Investment Risks |
Jan. 28, 2026 |
|---|---|
| Retail [Member] | Thornburg Global Opportunities Fund | Credit Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Credit Risk – The inability of an issuer to pay principal and interest on its debt obligations when due, or the downgrading of an issuer’s debt obligations by ratings agencies, may adversely affect the market’s perceptions of the issuer’s financial strength and may therefore result in declines in the issuer’s stock price. |
| Retail [Member] | Thornburg Global Opportunities Fund | Cybersecurity and Operational Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Cybersecurity and Operational Risk – Operational failures, cyber-attacks or other disruptions that affect the Fund’s service providers, the Fund’s counterparties, other market participants or the issuers of securities held by the Fund may adversely affect the Fund and its shareholders, including by causing losses for the Fund or impairing Fund operations. The rapid development and increasingly widespread use of artificial intelligence, including machine learning technology and generative artificial intelligence such as ChatGPT, could exacerbate these risks. |
| Retail [Member] | Thornburg Global Opportunities Fund | Developing Country Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Developing Country Risk – The risks which may affect investments in foreign issuers (see “Foreign Investment Risk,” below) may be more pronounced for investments in developing countries because the economies of those countries are usually less diversified, communications, transportation and economic infrastructures are less developed, and developing countries ordinarily have less established legal, political, business and social frameworks. At times the prices of equity securities of a developing country issuer may be extremely volatile. An issuer domiciled in a developed country may be similarly affected by these developing country risks to the extent that the issuer conducts its business in developing countries. |
| Retail [Member] | Thornburg Global Opportunities Fund | Equity Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Equity Risk – The value of the Fund’s equity investments may fluctuate significantly over time in response to factors affecting individual issuers, particular industries, or the market as a whole. Additionally, common stock ranks below preferred stock and debt securities in claims for dividends and for assets of a company in a liquidation or bankruptcy. |
| Retail [Member] | Thornburg Global Opportunities Fund | Foreign Currency Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Foreign Currency Risk – Fluctuations in currency exchange rates can adversely affect the value of the Fund’s foreign investments. Such fluctuations may occur for a number of reasons, including market and economic conditions, or a government’s decision to devalue its currency or impose currency controls. |
| Retail [Member] | Thornburg Global Opportunities Fund | Foreign Investment Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Foreign Investment Risk – Investments in securities of foreign issuers may involve risks including adverse fluctuations in currency exchange rates, political instability, confiscations, taxes or restrictions on currency exchange, difficulty in selling foreign investments, and reduced legal protection. |
| Retail [Member] | Thornburg Global Opportunities Fund | Liquidity Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Liquidity Risk – Due to a lack of demand in the marketplace or other factors, the Fund may not be able to sell some or all of its investments promptly, or may only be able to sell investments at less than desired prices. This risk may be more pronounced for the Fund’s investments in developing countries. |
| Retail [Member] | Thornburg Global Opportunities Fund | Management Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Management Risk – The Fund is an actively managed portfolio, and the value of the Fund may be reduced if Thornburg pursues unsuccessful investments or fails to correctly identify risks affecting the broad economy or specific issuers in which the Fund invests. |
| Retail [Member] | Thornburg Global Opportunities Fund | Market and Economic Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Market and Economic Risk – The value of the Fund’s investments may decline and its share value may be reduced due to changes in general economic and market conditions. The value of a security may change in response to developments affecting entire economies, markets or industries, including changes in interest rates, political, legal, and technological developments, and general market volatility. |
| Retail [Member] | Thornburg Global Opportunities Fund | Real Estate Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Real Estate Risk – The Fund’s investments in publicly traded real estate investment trusts (“REITs”) are subject to risks affecting real estate investments generally (including market conditions, competition, property obsolescence, changes in interest rates and casualty to real estate), as well as risks specifically affecting REITs (the quality and skill of REIT management and the internal expenses of the REIT). |
| Retail [Member] | Thornburg Global Opportunities Fund | Redemption Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Redemption Risk – If a significant percentage of the Fund’s shares is owned or controlled by a single shareholder, the Fund is subject to the risk that a redemption by that shareholder of all or a large portion of its shares may require the Fund to sell securities at less than desired prices, and the Fund’s remaining shareholders may also incur additional transaction costs or adverse tax consequences from such trading activity. |
| Retail [Member] | Thornburg Global Opportunities Fund | Risks Affecting Specific Countries or Regions [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Risks Affecting Specific Countries or Regions – If a significant portion of the Fund’s assets is invested in issuers that are economically exposed to one country or region, the Fund’s share value may be more susceptible to the conditions and developments in that country or region, and potentially more volatile than the share value of a more geographically diversified fund. A specific country or region could also be adversely affected by conditions or developments arising in other countries. For example, the U.S. government could take actions to prohibit or restrict individuals or companies within the U.S. from purchasing or holding the shares of issuers in another country, which may limit the Fund’s ability to invest in that country or cause the Fund to have to sell investments in that country at less than desired prices. The nature and degree of the risks affecting a given country or region, and the extent of the Fund’s exposure to any such country or region, is expected to vary over time. |
| Retail [Member] | Thornburg Global Opportunities Fund | Risks Affecting Specific Issuers [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Risks Affecting Specific Issuers – The value of a security may decline in response to developments affecting the specific issuer of the security, even if the overall industry or economy is unaffected. These developments may include a variety of factors, including but not limited to management issues or other corporate disruption, a decline in revenues or profitability, an increase in costs, or an adverse effect on the issuer’s competitive position. |
| Retail [Member] | Thornburg Global Opportunities Fund | Small and Mid-Cap Company Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Small and Mid-Cap Company Risk – Investments in small-capitalization companies and mid-capitalization companies may involve additional risks, which may be relatively higher with smaller companies. These additional risks may result from limited product lines, more limited access to markets and financial resources, greater vulnerability to competition and changes in markets, lack of management depth, increased volatility in share price, and possible difficulties in valuing or selling these investments. Additional information about Fund investments, investment strategies and risks of investing in the Fund appears beginning on page 125 of the Prospectus. |
| Retail [Member] | Thornburg Global Opportunities Fund | Risk Lose Money [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Accordingly, the loss of money is a risk of investing in the Fund. |
| Retail [Member] | Thornburg Global Opportunities Fund | Risk Not Insured [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | An investment in the Fund is not a deposit in any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. |
| Retail [Member] | Thornburg International Equity Fund | Credit Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Credit Risk – The inability of an issuer to pay principal and interest on its debt obligations when due, or the downgrading of an issuer’s debt obligations by ratings agencies, may adversely affect the market’s perceptions of the issuer’s financial strength and may therefore result in declines in the issuer’s stock price. |
| Retail [Member] | Thornburg International Equity Fund | Cybersecurity and Operational Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Cybersecurity and Operational Risk – Operational failures, cyber-attacks or other disruptions that affect the Fund’s service providers, the Fund’s counterparties, other market participants or the issuers of securities held by the Fund may adversely affect the Fund and its shareholders, including by causing losses for the Fund or impairing Fund operations. The rapid development and increasingly widespread use of artificial intelligence, including machine learning technology and generative artificial intelligence such as ChatGPT, could exacerbate these risks. |
| Retail [Member] | Thornburg International Equity Fund | Developing Country Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Developing Country Risk – The risks which may affect investments in foreign issuers (see “Foreign Investment Risk,” below) may be more pronounced for investments in developing countries because the economies of those countries are usually less diversified, communications, transportation and economic infrastructures are less developed, and developing countries ordinarily have less established legal, political, business and social frameworks. At times the prices of equity securities of a developing country issuer may be extremely volatile. An issuer domiciled in a developed country may be similarly affected by these developing country risks to the extent that the issuer conducts its business in developing countries. |
| Retail [Member] | Thornburg International Equity Fund | Equity Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Equity Risk – The value of the Fund’s equity investments may fluctuate significantly over time in response to factors affecting individual issuers, particular industries, or the market as a whole. Additionally, common stock ranks below preferred stock and debt securities in claims for dividends and for assets of a company in a liquidation or bankruptcy. |
| Retail [Member] | Thornburg International Equity Fund | Foreign Currency Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Foreign Currency Risk – Fluctuations in currency exchange rates can adversely affect the value of the Fund’s foreign investments. Such fluctuations may occur for a number of reasons, including market and economic conditions, or a government’s decision to devalue its currency or impose currency controls. |
| Retail [Member] | Thornburg International Equity Fund | Foreign Investment Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Foreign Investment Risk – Investments in securities of foreign issuers may involve risks including adverse fluctuations in currency exchange rates, political instability, confiscations, taxes or restrictions on currency exchange, difficulty in selling foreign investments, and reduced legal protection. |
| Retail [Member] | Thornburg International Equity Fund | Liquidity Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Liquidity Risk – Due to a lack of demand in the marketplace or other factors, the Fund may not be able to sell some or all of its investments promptly, or may only be able to sell investments at less than desired prices. |
| Retail [Member] | Thornburg International Equity Fund | Management Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Management Risk – The Fund is an actively managed portfolio, and the value of the Fund may be reduced if Thornburg pursues unsuccessful investments or fails to correctly identify risks affecting the broad economy or specific issuers in which the Fund invests. |
| Retail [Member] | Thornburg International Equity Fund | Market and Economic Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Market and Economic Risk – The value of the Fund’s investments may decline and its share value may be reduced due to changes in general economic and market conditions. The value of a security may change in response to developments affecting entire economies, markets or industries, including changes in interest rates, political, legal, and technological developments, and general market volatility. |
| Retail [Member] | Thornburg International Equity Fund | Redemption Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Redemption Risk – If a significant percentage of the Fund’s shares is owned or controlled by a single shareholder, the Fund is subject to the risk that a redemption by that shareholder of all or a large portion of its shares may require the Fund to sell securities at less than desired prices, and the Fund’s remaining shareholders may also incur additional transaction costs or adverse tax consequences from such trading activity. |
| Retail [Member] | Thornburg International Equity Fund | Risks Affecting Specific Countries or Regions [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Risks Affecting Specific Countries or Regions – If a significant portion of the Fund’s assets is invested in issuers that are economically exposed to one country or region, the Fund’s share value may be more susceptible to the conditions and developments in that country or region, and potentially more volatile than the share value of a more geographically diversified fund. A specific country or region could also be adversely affected by conditions or developments arising in other countries. For example, the U.S. government could take actions to prohibit or restrict individuals or companies within the U.S. from purchasing or holding the shares of issuers in another country, which may limit the Fund’s ability to invest in that country or cause the Fund to have to sell investments in that country at less than desired prices. The nature and degree of the risks affecting a given country or region, and the extent of the Fund’s exposure to any such country or region, is expected to vary over time. |
| Retail [Member] | Thornburg International Equity Fund | Risks Affecting Specific Issuers [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Risks Affecting Specific Issuers – The value of a security may decline in response to developments affecting the specific issuer of the security, even if the overall industry or economy is unaffected. These developments may include a variety of factors, including but not limited to management issues or other corporate disruption, a decline in revenues or profitability, an increase in costs, or an adverse effect on the issuer’s competitive position. |
| Retail [Member] | Thornburg International Equity Fund | Small and Mid-Cap Company Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Small and Mid-Cap Company Risk – Investments in small-capitalization companies and mid-capitalization companies may involve additional risks, which may be relatively higher with smaller companies. These additional risks may result from limited product lines, more limited access to markets and financial resources, greater vulnerability to competition and changes in markets, lack of management depth, increased volatility in share price, and possible difficulties in valuing or selling these investments. Additional information about Fund investments, investment strategies, and risks of investing in the Fund appears below beginning on page 125 of the Prospectus. |
| Retail [Member] | Thornburg International Equity Fund | Depositary Receipts Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Depositary Receipts Risk – An investment in American Depositary Receipts (“ADRs”), European Depositary Receipts (“EDRs”) or Global Depositary Receipts (“GDRs”) is an alternative to the purchase of the underlying securities in their national markets and/or currencies. However, ADRs, EDRs, and GDRs remain subject to many of the risks associated with investing directly in foreign securities, including the political and economic risks associated with the underlying issuer’s country. Certain countries may limit the ability to convert a depositary receipt into the underlying foreign security and vice versa, which may cause the securities of the foreign company to trade at a discount or premium to the market price of the related depositary receipts. Moreover, EDRs and GDRs can involve currency risk since, unlike ADRs, they may not be U.S. dollar denominated. |
| Retail [Member] | Thornburg International Equity Fund | Risk Lose Money [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Accordingly, the loss of money is a risk of investing in the Fund. |
| Retail [Member] | Thornburg International Equity Fund | Risk Not Insured [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | An investment in the Fund is not a deposit in any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. |
| Retail [Member] | Thornburg Better World International Fund | Credit Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Credit Risk – The inability of an issuer to pay principal and interest on its debt obligations when due, or the downgrading of an issuer’s debt obligations by ratings agencies, may adversely affect the market’s perceptions of the issuer’s financial strength and may therefore result in declines in the issuer’s stock price. |
| Retail [Member] | Thornburg Better World International Fund | Cybersecurity and Operational Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Cybersecurity and Operational Risk – Operational failures, cyber-attacks or other disruptions that affect the Fund’s service providers, the Fund’s counterparties, other market participants or the issuers of securities held by the Fund may adversely affect the Fund and its shareholders, including by causing losses for the Fund or impairing Fund operations. The rapid development and increasingly widespread use of artificial intelligence, including machine learning technology and generative artificial intelligence such as ChatGPT, could exacerbate these risks. |
| Retail [Member] | Thornburg Better World International Fund | Developing Country Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Developing Country Risk – The risks which may affect investments in foreign issuers (see “Foreign Investment Risk,” below) may be more pronounced for investments in developing countries because the economies of those countries are usually less diversified, communications, transportation and economic infrastructures are less developed, and developing countries ordinarily have less established legal, political, business and social frameworks. At times the prices of equity securities of a developing country issuer may be extremely volatile. An issuer domiciled in a developed country may be similarly affected by these developing country risks to the extent that the issuer conducts its business in developing countries. |
| Retail [Member] | Thornburg Better World International Fund | Equity Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Equity Risk – The value of the Fund’s equity investments may fluctuate significantly over time in response to factors affecting individual issuers, particular industries, or the market as a whole. Additionally, common stock ranks below preferred stock and debt securities in claims for dividends and for assets of a company in a liquidation or bankruptcy. |
| Retail [Member] | Thornburg Better World International Fund | Foreign Currency Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Foreign Currency Risk – Fluctuations in currency exchange rates can adversely affect the value of the Fund’s foreign investments. Such fluctuations may occur for a number of reasons, including market and economic conditions, or a government’s decision to devalue its currency or impose currency controls. |
| Retail [Member] | Thornburg Better World International Fund | Foreign Investment Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Foreign Investment Risk – Investments in securities of foreign issuers may involve risks including adverse fluctuations in currency exchange rates, political instability, confiscations, taxes or restrictions on currency exchange, difficulty in selling foreign investments, and reduced legal protection. |
| Retail [Member] | Thornburg Better World International Fund | Liquidity Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Liquidity Risk – Due to a lack of demand in the marketplace or other factors, the Fund may not be able to sell some or all of its investments promptly, or may only be able to sell investments at less than desired prices. This risk may be more pronounced for the Fund’s investments in developing countries. |
| Retail [Member] | Thornburg Better World International Fund | Management Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Management Risk – The Fund is an actively managed portfolio, and the value of the Fund may be reduced if Thornburg pursues unsuccessful investments or fails to correctly identify risks affecting the broad economy or specific issuers in which the Fund invests. |
| Retail [Member] | Thornburg Better World International Fund | Market and Economic Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Market and Economic Risk – The value of the Fund’s investments may decline and its share value may be reduced due to changes in general economic and market conditions. The value of a security may change in response to developments affecting entire economies, markets or industries, including changes in interest rates, political, legal, and technological developments, and general market volatility. |
| Retail [Member] | Thornburg Better World International Fund | Real Estate Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Real Estate Risk – The Fund’s investments in publicly traded real estate investment trusts (“REITs”) are subject to risks affecting real estate investments generally (including market conditions, competition, property obsolescence, changes in interest rates and casualty to real estate), as well as risks specifically affecting REITs (the quality and skill of REIT management and the internal expenses of the REIT). |
| Retail [Member] | Thornburg Better World International Fund | Redemption Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Redemption Risk – If a significant percentage of the Fund’s shares is owned or controlled by a single shareholder, the Fund is subject to the risk that a redemption by that shareholder of all or a large portion of its shares may require the Fund to sell securities at less than desired prices, and the Fund’s remaining shareholders may also incur additional transaction costs or adverse tax consequences from such trading activity. |
| Retail [Member] | Thornburg Better World International Fund | Risks Affecting Specific Countries or Regions [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Risks Affecting Specific Countries or Regions – If a significant portion of the Fund’s assets is invested in issuers that are economically exposed to one country or region, the Fund’s share value may be more susceptible to the conditions and developments in that country or region, and potentially more volatile than the share value of a more geographically diversified fund. A specific country or region could also be adversely affected by conditions or developments arising in other countries. For example, the U.S. government could take actions to prohibit or restrict individuals or companies within the U.S. from purchasing or holding the shares of issuers in another country, which may limit the Fund’s ability to invest in that country or cause the Fund to have to sell investments in that country at less than desired prices. The nature and degree of the risks affecting a given country or region, and the extent of the Fund’s exposure to any such country or region, is expected to vary over time. |
| Retail [Member] | Thornburg Better World International Fund | Risks Affecting Specific Issuers [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Risks Affecting Specific Issuers – The value of a security may decline in response to developments affecting the specific issuer of the security, even if the overall industry or economy is unaffected. These developments may include a variety of factors, including but not limited to management issues or other corporate disruption, a decline in revenues or profitability, an increase in costs, or an adverse effect on the issuer’s competitive position. |
| Retail [Member] | Thornburg Better World International Fund | Small and Mid-Cap Company Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Small and Mid-Cap Company Risk – Investments in small capitalization companies and mid-capitalization companies may involve additional risks, which may be relatively higher with smaller companies. These additional risks may result from limited product lines, more limited access to markets and financial resources, greater vulnerability to competition and changes in markets, lack of management depth, increased volatility in share price, and possible difficulties in valuing or selling these investments. Additional information about Fund investments, investment strategies and risks of investing in the Fund appears beginning on page 125 of the Prospectus. |
| Retail [Member] | Thornburg Better World International Fund | Depositary Receipts Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Depositary Receipts Risk – An investment in American Depositary Receipts (“ADRs”), European Depositary Receipts (“EDRs”) or Global Depositary Receipts (“GDRs”) is an alternative to the purchase of the underlying securities in their national markets and/or currencies. However, ADRs, EDRs, and GDRs remain subject to many of the risks associated with investing directly in foreign securities, including the political and economic risks associated with the underlying issuer’s country. Certain countries may limit the ability to convert a depositary receipt into the underlying foreign security and vice versa, which may cause the securities of the foreign company to trade at a discount or premium to the market price of the related depositary receipts. Moreover, EDRs and GDRs can involve currency risk since, unlike ADRs, they may not be U.S. dollar denominated. |
| Retail [Member] | Thornburg Better World International Fund | ESG Investing Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | ESG Investing Risk – Thornburg’s assessments of company ESG characteristics may result in decisions not to purchase, or to sell, investments which are otherwise consistent with the Fund’s investment goal and subsequently produce attractive investment performance, and Thornburg’s assessments of these characteristics may at times reduce the Fund’s exposure to market sectors or types of investments that produce positive investment performance. The application of ESG principles and the perceptions of the commitment of a given company to ESG principles vary among investors, analysts and other market observers. Consequently, Thornburg’s assessments respecting the ESG characteristics associated with any company may differ from the perceptions of other persons, including other mutual funds. Additionally, it may be difficult in certain instances for Thornburg to evaluate correctly a company’s commitment to positive ESG practices, and a failure to do so may result in investment in companies with practices that are not consistent with the Fund’s aspirations. |
| Retail [Member] | Thornburg Better World International Fund | Risk Lose Money [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Accordingly, the loss of money is a risk of investing in the Fund. |
| Retail [Member] | Thornburg Better World International Fund | Risk Not Insured [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | An investment in the Fund is not a deposit in any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. |
| Retail [Member] | Thornburg International Growth Fund | Credit Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Credit Risk – The inability of an issuer to pay principal and interest on its debt obligations when due, or the downgrading of an issuer’s debt obligations by ratings agencies, may adversely affect the market’s perceptions of the issuer’s financial strength and may therefore result in declines in the issuer’s stock price. |
| Retail [Member] | Thornburg International Growth Fund | Cybersecurity and Operational Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Cybersecurity and Operational Risk – Operational failures, cyber-attacks or other disruptions that affect the Fund’s service providers, the Fund’s counterparties, other market participants or the issuers of securities held by the Fund may adversely affect the Fund and its shareholders, including by causing losses for the Fund or impairing Fund operations. The rapid development and increasingly widespread use of artificial intelligence, including machine learning technology and generative artificial intelligence such as ChatGPT, could exacerbate these risks. |
| Retail [Member] | Thornburg International Growth Fund | Developing Country Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Developing Country Risk – The risks which may affect investments in foreign issuers (see “Foreign Investment Risk,” below) may be more pronounced for investments in developing countries because the economies of those countries are usually less diversified, communications, transportation and economic infrastructures are less developed, and developing countries ordinarily have less established legal, political, business and social frameworks. At times the prices of equity securities of a developing country issuer may be extremely volatile. An issuer domiciled in a developed country may be similarly affected by these developing country risks to the extent that the issuer conducts its business in developing countries. |
| Retail [Member] | Thornburg International Growth Fund | Equity Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Equity Risk – The value of the Fund’s equity investments may fluctuate significantly over time in response to factors affecting individual issuers, particular industries, or the market as a whole. Additionally, common stock ranks below preferred stock and debt securities in claims for dividends and for assets of a company in a liquidation or bankruptcy. |
| Retail [Member] | Thornburg International Growth Fund | Foreign Currency Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Foreign Currency Risk – Fluctuations in currency exchange rates can adversely affect the value of the Fund’s foreign investments. Such fluctuations may occur for a number of reasons, including market and economic conditions, or a government’s decision to devalue its currency or impose currency controls. |
| Retail [Member] | Thornburg International Growth Fund | Foreign Investment Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Foreign Investment Risk – Investments in securities of foreign issuers may involve risks including adverse fluctuations in currency exchange rates, political instability, confiscations, taxes or restrictions on currency exchange, difficulty in selling foreign investments, and reduced legal protection. |
| Retail [Member] | Thornburg International Growth Fund | Liquidity Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Liquidity Risk – Due to a lack of demand in the marketplace or other factors, the Fund may not be able to sell some or all of its investments promptly, or may only be able to sell investments at less than desired prices. This risk may be more pronounced for the Fund’s investments in developing countries. |
| Retail [Member] | Thornburg International Growth Fund | Management Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Management Risk – The Fund is an actively managed portfolio, and the value of the Fund may be reduced if Thornburg pursues unsuccessful investments or fails to correctly identify risks affecting the broad economy or specific issuers in which the Fund invests. |
| Retail [Member] | Thornburg International Growth Fund | Market and Economic Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Market and Economic Risk – The value of the Fund’s investments may decline and its share value may be reduced due to changes in general economic and market conditions. The value of a security may change in response to developments affecting entire economies, markets or industries, including changes in interest rates, political, legal, and technological developments, and general market volatility. |
| Retail [Member] | Thornburg International Growth Fund | Redemption Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Redemption Risk – If a significant percentage of the Fund’s shares is owned or controlled by a single shareholder, the Fund is subject to the risk that a redemption by that shareholder of all or a large portion of its shares may require the Fund to sell securities at less than desired prices, and the Fund’s remaining shareholders may also incur additional transaction costs or adverse tax consequences from such trading activity. |
| Retail [Member] | Thornburg International Growth Fund | Risks Affecting Specific Countries or Regions [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Risks Affecting Specific Countries or Regions – If a significant portion of the Fund’s assets is invested in issuers that are economically exposed to one country or region, the Fund’s share value may be more susceptible to the conditions and developments in that country or region, and potentially more volatile than the share value of a more geographically diversified fund. A specific country or region could also be adversely affected by conditions or developments arising in other countries. For example, the U.S. government could take actions to prohibit or restrict individuals or companies within the U.S. from purchasing or holding the shares of issuers in another country, which may limit the Fund’s ability to invest in that country or cause the Fund to have to sell investments in that country at less than desired prices. The nature and degree of the risks affecting a given country or region, and the extent of the Fund’s exposure to any such country or region, is expected to vary over time. |
| Retail [Member] | Thornburg International Growth Fund | Risks Affecting Specific Issuers [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Risks Affecting Specific Issuers – The value of a security may decline in response to developments affecting the specific issuer of the security, even if the overall industry or economy is unaffected. These developments may include a variety of factors, including but not limited to management issues or other corporate disruption, a decline in revenues or profitability, an increase in costs, or an adverse effect on the issuer’s competitive position. |
| Retail [Member] | Thornburg International Growth Fund | Small and Mid-Cap Company Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Small and Mid-Cap Company Risk – Investments in small-capitalization companies and mid-capitalization companies, including smaller, earlier stage companies, may involve additional risks. These risks may be relatively higher with smaller companies. These additional risks may result from limited product lines, more limited access to markets and financial resources, greater vulnerability to competition and changes in markets, lack of management depth, increased volatility in share price, and possible difficulties in valuing or selling these investments. Additional information about Fund investments, investment strategies, and risks of investing in the Fund appears below beginning on page 125 of the Prospectus. |
| Retail [Member] | Thornburg International Growth Fund | Depositary Receipts Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Depositary Receipts Risk – An investment in American Depositary Receipts (“ADRs”), European Depositary Receipts (“EDRs”) or Global Depositary Receipts (“GDRs”) is an alternative to the purchase of the underlying securities in their national markets and/or currencies. However, ADRs, EDRs, and GDRs remain subject to many of the risks associated with investing directly in foreign securities, including the political and economic risks associated with the underlying issuer’s country. Certain countries may limit the ability to convert a depositary receipt into the underlying foreign security and vice versa, which may cause the securities of the foreign company to trade at a discount or premium to the market price of the related depositary receipts. Moreover, EDRs and GDRs can involve currency risk since, unlike ADRs, they may not be U.S. dollar denominated. |
| Retail [Member] | Thornburg International Growth Fund | Growth Company Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Growth Company Risk – Growth company stocks may trade at higher multiples of current earnings than other equity securities and, therefore, may be more sensitive to changes in current or expected earnings than other equity securities and may be more volatile. If growth companies do not increase their earnings at a rate expected by investors, the market price of the stock may decline significantly, even if earnings show an absolute increase. Growth company stocks also typically lack the dividend yield that can cushion stock prices in market downturns. These risks may be more pronounced in companies that are in the earlier stages of their growth cycle. |
| Retail [Member] | Thornburg International Growth Fund | Information Technology Securities Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Information Technology Securities Risk – Information technology companies may at times be more vulnerable to product obsolescence caused by rapid technology changes, the failure to obtain or maintain intellectual property rights, the inability to develop new products, competition from new and existing market entrants, and changes in consumer preferences. Information technology stocks may also be more volatile than the overall market. |
| Retail [Member] | Thornburg International Growth Fund | Risk Lose Money [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Accordingly, the loss of money is a risk of investing in the Fund. |
| Retail [Member] | Thornburg International Growth Fund | Risk Not Insured [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | An investment in the Fund is not a deposit in any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. |
| Retail [Member] | Thornburg Developing World Fund | Credit Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Credit Risk – The inability of an issuer to pay principal and interest on its debt obligations when due, or the downgrading of an issuer’s debt obligations by ratings agencies, may adversely affect the market’s perceptions of the issuer’s financial strength and may therefore result in declines in the issuer’s stock price. |
| Retail [Member] | Thornburg Developing World Fund | Cybersecurity and Operational Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Cybersecurity and Operational Risk – Operational failures, cyber-attacks or other disruptions that affect the Fund’s service providers, the Fund’s counterparties, other market participants or the issuers of securities held by the Fund may adversely affect the Fund and its shareholders, including by causing losses for the Fund or impairing Fund operations. The rapid development and increasingly widespread use of artificial intelligence, including machine learning technology and generative artificial intelligence such as ChatGPT, could exacerbate these risks. |
| Retail [Member] | Thornburg Developing World Fund | Developing Country Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Developing Country Risk – The risks which may affect investments in foreign issuers (see “Foreign Investment Risk,” below) may be more pronounced for investments in developing countries because the economies of those countries are usually less diversified, communications, transportation and economic infrastructures are less developed, and developing countries ordinarily have less established legal, political, business and social frameworks. At times the prices of equity securities of a developing country issuer may be extremely volatile. An issuer domiciled in a developed country may be similarly affected by these developing country risks to the extent that the issuer conducts its business in developing countries. |
| Retail [Member] | Thornburg Developing World Fund | Equity Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Equity Risk – The value of the Fund’s equity investments may fluctuate significantly over time in response to factors affecting individual issuers, particular industries, or the market as a whole. Additionally, common stock ranks below preferred stock and debt securities in claims for dividends and for assets of a company in a liquidation or bankruptcy. |
| Retail [Member] | Thornburg Developing World Fund | Foreign Currency Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Foreign Currency Risk – Fluctuations in currency exchange rates can adversely affect the value of the Fund’s foreign investments. Such fluctuations may occur for a number of reasons, including market and economic conditions, or a government’s decision to devalue its currency or impose currency controls. |
| Retail [Member] | Thornburg Developing World Fund | Foreign Investment Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Foreign Investment Risk – Investments in securities of foreign issuers may involve risks including adverse fluctuations in currency exchange rates, political instability, confiscations, taxes or restrictions on currency exchange, difficulty in selling foreign investments, and reduced legal protections. |
| Retail [Member] | Thornburg Developing World Fund | Liquidity Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Liquidity Risk – Due to a lack of demand in the marketplace or other factors, the Fund may not be able to sell some or all of its investments promptly, or may only be able to sell investments at less than desired prices. This risk may be more pronounced for the Fund’s investments in developing countries. |
| Retail [Member] | Thornburg Developing World Fund | Management Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Management Risk – The Fund is an actively managed portfolio, and the value of the Fund may be reduced if Thornburg pursues unsuccessful investments or fails to correctly identify risks affecting the broad economy or specific issuers in which the Fund invests. |
| Retail [Member] | Thornburg Developing World Fund | Market and Economic Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Market and Economic Risk – The value of the Fund’s investments may decline and its share value may be reduced due to changes in general economic and market conditions. The value of a security may change in response to developments affecting entire economies, markets or industries, including changes in interest rates, political, legal, and technological developments, and general market volatility. These risks may be more pronounced for the Fund’s investments in developing countries. |
| Retail [Member] | Thornburg Developing World Fund | Redemption Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Redemption Risk – If a significant percentage of the Fund’s shares is owned or controlled by a single shareholder, the Fund is subject to the risk that a redemption by that shareholder of all or a large portion of its shares may require the Fund to sell securities at less than desired prices, and the Fund’s remaining shareholders may also incur additional transaction costs or adverse tax consequences from such trading activity. |
| Retail [Member] | Thornburg Developing World Fund | Risks Affecting Specific Countries or Regions [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Risks Affecting Specific Countries or Regions – If a significant portion of the Fund’s assets is invested in issuers that are economically exposed to one country or region, the Fund’s share value may be more susceptible to the conditions and developments in that country or region, and potentially more volatile than the share value of a more geographically diversified fund. A specific country or region could also be adversely affected by conditions or developments arising in other countries. For example, the U.S. government could take actions to prohibit or restrict individuals or companies within the U.S. from purchasing or holding the shares of issuers in another country, which may limit the Fund’s ability to invest in that country or cause the Fund to have to sell investments in that country at less than desired prices. The nature and degree of the risks affecting a given country or region, and the extent of the Fund’s exposure to any such country or region, is expected to vary over time. |
| Retail [Member] | Thornburg Developing World Fund | Risks Affecting Specific Issuers [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Risks Affecting Specific Issuers – The value of an equity security may decline in response to developments affecting the specific issuer of the security or obligation, even if the overall industry or economy is unaffected. These developments may include a variety of factors, including but not limited to management issues or other corporate disruption, a decline in revenues or profitability, an increase in costs, or an adverse effect on the issuer’s competitive position. |
| Retail [Member] | Thornburg Developing World Fund | Small and Mid-Cap Company Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Small and Mid-Cap Company Risk – Investments in small-capitalization companies and mid-capitalization companies may involve additional risks, which may be relatively higher with smaller companies. These additional risks may result from limited product lines, more limited access to markets and financial resources, greater vulnerability to competition and changes in markets, lack of management depth, increased volatility in share price, and possible difficulties in valuing or selling these investments. |
| Retail [Member] | Thornburg Developing World Fund | Risk Lose Money [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Accordingly, the loss of money is a risk of investing in the Fund. |
| Retail [Member] | Thornburg Developing World Fund | Risk Not Insured [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | An investment in the Fund is not a deposit in any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. |
| Retail [Member] | Thornburg Investment Income Builder Fund | Credit Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Credit Risk – If debt obligations held by the Fund are downgraded by ratings agencies or go into default, or if management action, legislation or other government action reduces the ability of issuers to pay principal and interest when due, the value of those obligations may decline and the Fund’s share value and the dividends paid by the Fund may be reduced. Because the ability of an issuer of a lower-rated or unrated obligation to pay principal and interest when due is typically less certain than for an issuer of a higher-rated obligation, lower-rated and unrated obligations are generally more vulnerable than higher-rated obligations to default, to ratings downgrades, and to liquidity risk. The inability of an issuer to pay principal and interest on its debt obligations when due, or the downgrading of an issuer’s debt obligations by ratings agencies, may adversely affect the market’s perceptions of the issuer’s financial strength and may therefore result in declines in the issuer’s stock price. |
| Retail [Member] | Thornburg Investment Income Builder Fund | Cybersecurity and Operational Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Cybersecurity and Operational Risk – Operational failures, cyber-attacks or other disruptions that affect the Fund’s service providers, the Fund’s counterparties, other market participants or the issuers of securities held by the Fund may adversely affect the Fund and its shareholders, including by causing losses for the Fund or impairing Fund operations. The rapid development and increasingly widespread use of artificial intelligence, including machine learning technology and generative artificial intelligence such as ChatGPT, could exacerbate these risks. |
| Retail [Member] | Thornburg Investment Income Builder Fund | Developing Country Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Developing Country Risk – The risks which may affect investments in foreign issuers (see “Foreign Investment Risk,” below) may be more pronounced for investments in developing countries because the economies of those countries are usually less diversified, communications, transportation and economic infrastructures are less developed, and developing countries ordinarily have less established legal, political, business and social frameworks. At times the prices of equity securities or debt obligations of a developing country issuer may be extremely volatile. An issuer domiciled in a developed country may be similarly affected by these developing country risks to the extent that the issuer conducts its business in developing countries. |
| Retail [Member] | Thornburg Investment Income Builder Fund | Equity Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Equity Risk – The value of the Fund’s equity investments may fluctuate significantly over time in response to factors affecting individual issuers, particular industries, or the market as a whole. Additionally, common stock ranks below preferred stock and debt securities in claims for dividends and for assets of a company in a liquidation or bankruptcy. |
| Retail [Member] | Thornburg Investment Income Builder Fund | Foreign Currency Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Foreign Currency Risk – Fluctuations in currency exchange rates can adversely affect the value of the Fund’s foreign investments. Such fluctuations may occur for a number of reasons, including market and economic conditions, or a government’s decision to devalue its currency or impose currency controls. |
| Retail [Member] | Thornburg Investment Income Builder Fund | Foreign Investment Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Foreign Investment Risk – Investments in securities of foreign issuers may involve risks including adverse fluctuations in currency exchange rates, political instability, confiscations, taxes or restrictions on currency exchange, difficulty in selling foreign investments, and reduced legal protection. In addition, some foreign government debt obligations may be subject to default, delays in payment, adverse legislation or government action, or could be downgraded by ratings agencies. |
| Retail [Member] | Thornburg Investment Income Builder Fund | Liquidity Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Liquidity Risk – Due to a lack of demand in the marketplace or other factors, the Fund may not be able to sell some or all of its investments promptly, or may only be able to sell investments at less than desired prices. |
| Retail [Member] | Thornburg Investment Income Builder Fund | Management Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Management Risk – The Fund is an actively managed portfolio, and the value of the Fund may be reduced if Thornburg pursues unsuccessful investments or fails to correctly identify risks affecting the broad economy or specific issuers in which the Fund invests. |
| Retail [Member] | Thornburg Investment Income Builder Fund | Market and Economic Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Market and Economic Risk – The value of the Fund’s investments may decline and its share value may be reduced due to changes in general economic and market conditions. The value of a security may change in response to developments affecting entire economies, markets or industries, including changes in interest rates, political, legal, and technological developments, and general market volatility. |
| Retail [Member] | Thornburg Investment Income Builder Fund | Real Estate Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Real Estate Risk – The Fund’s investments in publicly traded real estate investment trusts (“REITs”) are subject to risks affecting real estate investments generally (including market conditions, competition, property obsolescence, changes in interest rates and casualty to real estate), as well as risks specifically affecting REITs (the quality and skill of REIT management and the internal expenses of the REIT). |
| Retail [Member] | Thornburg Investment Income Builder Fund | Redemption Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Redemption Risk – If a significant percentage of the Fund’s shares is owned or controlled by a single shareholder, the Fund is subject to the risk that a redemption by that shareholder of all or a large portion of its shares may require the Fund to sell securities at less than desired prices, and the Fund’s remaining shareholders may also incur additional transaction costs or adverse tax consequences from such trading activity. |
| Retail [Member] | Thornburg Investment Income Builder Fund | Risks Affecting Specific Countries or Regions [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Risks Affecting Specific Countries or Regions – If a significant portion of the Fund’s assets is invested in issuers that are economically exposed to one country or region, the Fund’s share value may be more susceptible to the conditions and developments in that country or region, and potentially more volatile than the share value of a more geographically diversified fund. A specific country or region could also be adversely affected by conditions or developments arising in other countries. For example, the U.S. government could take actions to prohibit or restrict individuals or companies within the U.S. from purchasing or holding the shares of issuers in another country, which may limit the Fund’s ability to invest in that country or cause the Fund to have to sell investments in that country at less than desired prices. The nature and degree of the risks affecting a given country or region, and the extent of the Fund’s exposure to any such country or region, is expected to vary over time. |
| Retail [Member] | Thornburg Investment Income Builder Fund | Risks Affecting Specific Issuers [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Risks Affecting Specific Issuers – The value of an equity security or debt obligation may decline in response to developments affecting the specific issuer of the security or obligation, even if the overall industry or economy is unaffected. These developments may include a variety of factors, including but not limited to management issues or other corporate disruption, a decline in revenues or profitability, an increase in costs, or an adverse effect on the issuer’s competitive position. |
| Retail [Member] | Thornburg Investment Income Builder Fund | Small and Mid-Cap Company Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Small and Mid-Cap Company Risk – Investments in small-capitalization companies and mid-capitalization companies may involve additional risks, which may be relatively higher with smaller companies. These additional risks may result from limited product lines, more limited access to markets and financial resources, greater vulnerability to competition and changes in markets, lack of management depth, increased volatility in share price, and possible difficulty in valuing or selling these investments. |
| Retail [Member] | Thornburg Investment Income Builder Fund | Convertible Debt Obligation Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Convertible Debt Obligation Risk – The market value of a convertible debt obligation may vary with changes in prevailing interest rates and changing evaluations of the ability of the issuer to meet principal and interest payments. The market value of a convertible debt obligation may also vary in accordance with the market value of the underlying stock. As a result, convertible debt obligations held by the Fund will tend to perform more like equity securities when the underlying stock price is high (because it is assumed that the Fund will convert the obligation), and more like non-convertible debt obligations when the underlying stock price is low (because it is assumed that the Fund will not convert the obligation). Because its market value can be influenced by several factors, a convertible debt obligation will not be as sensitive to interest rate changes as a similar non-convertible debt obligation, and generally will have less potential for gain or loss than the underlying stock. |
| Retail [Member] | Thornburg Investment Income Builder Fund | Foreign Government Obligations Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Foreign Government Obligations Risk – Debt obligations may be issued by foreign governments and their agencies and instrumentalities, including the governments of developing countries and “supra-national” entities such as the International Bank for Reconstruction and Development. The Fund’s investments in these foreign debt obligations may be denominated in U.S. dollars or in foreign currencies. These securities, even if denominated in U.S. dollars, may be affected significantly by fluctuations in the value of foreign currencies, and the value of these securities in U.S. dollars may decline even if the securities increase in value in their home country. The governmental issuers of these debt obligations may be less willing or able than the U.S. to repay principal and interest when due, and they may require that the terms for payment be renegotiated. In some countries there may be political instability or insufficient government supervision of markets, and the legal protections for the Fund’s investments could be subject to unfavorable judicial or administrative changes. These risks may be more pronounced for the Fund’s investments in debt obligations issued by developing countries. |
| Retail [Member] | Thornburg Investment Income Builder Fund | High Yield Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | High Yield Risk – Debt obligations that are rated below investment grade and unrated obligations of similar credit quality (commonly referred to as “junk” or “high yield” bonds) may have a substantial risk of loss. These obligations are generally considered to be speculative with respect to the issuer’s ability to pay interest and principal when due. These obligations may be subject to greater price volatility than investment grade obligations, and their prices may decline significantly in periods of general economic difficulty or in response to adverse publicity, changes in investor perceptions or other factors. These obligations may also be subject to greater liquidity risk. |
| Retail [Member] | Thornburg Investment Income Builder Fund | Interest Rate Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Interest Rate Risk – When interest rates increase, the value of the Fund’s investments in debt obligations may decline and the Fund’s share value may be reduced. This effect is typically more pronounced for intermediate and longer-term obligations. This effect is also typically more pronounced for mortgage- and other asset-backed securities, the value of which may fluctuate more significantly in response to interest rate changes. When interest rates decrease, the Fund’s dividends may decline. |
| Retail [Member] | Thornburg Investment Income Builder Fund | Prepayment and Extension Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Prepayment and Extension Risk – When market interest rates decline, certain debt obligations held by the Fund may be repaid more quickly than anticipated, requiring the Fund to reinvest the proceeds of those repayments in obligations which bear a lower interest rate. Conversely, when market interest rates increase, certain debt obligations held by the Fund may be repaid more slowly than anticipated, causing assets of the Fund to remain invested in relatively lower yielding obligations. These risks may be more pronounced for the Fund’s investments in mortgage-backed and asset-backed securities. |
| Retail [Member] | Thornburg Investment Income Builder Fund | U.S. Government Obligations Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | U.S. Government Obligations Risk – U.S. government obligations are subject to the same risks affecting other debt obligations. Although securities backed by the full faith credit of the U.S. government are commonly regarded as having relatively less risk of default, it is possible that the U.S. government may be unwilling or unable to repay principal and interest when due and may require that the terms for payment be renegotiated. Further obligations that are backed by the full faith and credit of the U.S. government remain subject to the other general risks applicable to debt obligations, such as market risks, liquidity risks, and interest rate risks, and may be subject to ratings downgrades. U.S. government obligations also include obligations of U.S. government agencies, instrumentalities, and government-sponsored enterprises, commonly referred to as “agency obligations.” Some agency obligations are backed by the full faith and credit of the U.S. government, but other agency obligations have no specific backing or only limited support from the agency’s authority to borrow from the U.S. government or the discretionary authority of the Treasury to purchase obligations of the issuing agency. |
| Retail [Member] | Thornburg Investment Income Builder Fund | Risk Lose Money [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Accordingly, the loss of money is a risk of investing in the Fund. |
| Retail [Member] | Thornburg Investment Income Builder Fund | Risk Not Insured [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | An investment in the Fund is not a deposit in any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. |
| Retail [Member] | Thornburg Summit Fund | Credit Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Credit Risk – If debt obligations held by the Fund are downgraded by ratings agencies or go into default, or if management action, legislation or other government action reduces the ability of issuers to pay principal and interest when due, the value of those obligations may decline and the Fund’s share value and any dividends paid by the Fund may be reduced. Because the ability of an issuer of a lower-rated or unrated debt obligation to pay principal and interest when due is typically less certain than for an issuer of a higher-rated debt obligation, lower-rated and unrated debt obligations are generally more vulnerable than higher-rated debt obligations to default, to ratings downgrades, and to liquidity risk. Debt obligations backed by so-called “subprime” mortgages may also be subject to a greater risk of default or downgrade. Debt obligations issued by the U.S. government or its agencies, instrumentalities and government sponsored enterprises are also subject to credit risk. Securities backed by the full faith and credit of the U.S. government, such as U.S. Treasury obligations, are commonly regarded as having small exposure to credit risk. Obligations of certain U.S. agencies, instrumentalities and enterprises (sometimes referred to as “agency obligations”) are not direct obligations of the U.S. government, may not be backed by the full faith and credit of the U.S. government, and may have a greater exposure to credit risk. The inability of an issuer to pay principal and interest on its debt obligations when due, or the downgrading of an issuer’s debt obligations by ratings agencies, may adversely affect the market’s perceptions of the issuer’s financial strength and may therefore result in declines in the issuer’s stock price. |
| Retail [Member] | Thornburg Summit Fund | Cybersecurity and Operational Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Cybersecurity and Operational Risk – Operational failures, cyber-attacks or other disruptions that affect the Fund’s service providers, the Fund’s counterparties, other market participants or the issuers of securities held by the Fund may adversely affect the Fund and its shareholders, including by causing losses for the Fund or impairing Fund operations. The rapid development and increasingly widespread use of artificial intelligence, including machine learning technology and generative artificial intelligence such as ChatGPT, could exacerbate these risks. |
| Retail [Member] | Thornburg Summit Fund | Developing Country Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Developing Country Risk – The risks which may affect investments in foreign issuers (see “Foreign Investment Risk,” below) may be more pronounced for investments in developing countries because the economies of those countries are usually less diversified, communications, transportation and economic infrastructures are less developed, and developing countries ordinarily have less established legal, political, business and social frameworks. At times the prices of equity securities or debt obligations of a developing country issuer may be extremely volatile. An issuer domiciled in a developed country may be similarly affected by these developing country risks to the extent that the issuer conducts a significant percentage of its business in developing countries. |
| Retail [Member] | Thornburg Summit Fund | Equity Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Equity Risk – The value of the Fund’s equity investments may fluctuate significantly over time in response to factors affecting individual issuers, particular industries, or the market as a whole. Additionally, common stock ranks below preferred stock and debt securities in claims for dividends and for assets of a company in a liquidation or bankruptcy. |
| Retail [Member] | Thornburg Summit Fund | Foreign Currency Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Foreign Currency Risk – Fluctuations in currency exchange rates can adversely affect the value of the Fund’s foreign investments. Such fluctuations may occur for a number of reasons, including market and economic conditions, or a government’s decision to devalue its currency or impose currency controls. |
| Retail [Member] | Thornburg Summit Fund | Foreign Investment Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Foreign Investment Risk – Investments in securities of foreign issuers and in depositary receipts may involve risks including adverse fluctuations in currency exchange rates, political instability, confiscations, taxes or restrictions on currency exchange, difficulty in selling foreign investments, and reduced legal protection. In addition, some foreign government debt obligations may be subject to default, delays in payment, adverse legislation or government action, or could be downgraded by ratings agencies. |
| Retail [Member] | Thornburg Summit Fund | Liquidity Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Liquidity Risk – Due to a lack of demand in the marketplace or other factors, the Fund may not be able to sell some or all of the investments promptly, or may only be able to sell investments at less than desired prices. This risk may be more pronounced for the Fund’s investments in developing countries. Additionally, the market for lower-rated and unrated debt obligations (including particularly “junk” or “high yield” bonds) and debt obligations backed by so-called “subprime” mortgages may be less liquid than the market for other obligations, making it difficult for the Fund to value its investment in a lower-rated or unrated obligation or to sell the investment in a timely manner or at an acceptable price. |
| Retail [Member] | Thornburg Summit Fund | Management Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Management Risk – The Fund is an actively managed portfolio, and the value of the Fund may be reduced or the Fund may otherwise be unsuccessful in pursuing its investment goal if Thornburg pursues unsuccessful investments or fails to correctly identify risks affecting the broad economy or specific issuers in which the Fund invests. |
| Retail [Member] | Thornburg Summit Fund | Market and Economic Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Market and Economic Risk – The value of the Fund’s investments may decline and its share value may be reduced due to changes in general economic and market conditions. The value of a security may change in response to developments affecting entire economies, markets or industries, including changes in interest rates, political and legal developments, and general market volatility. This effect is typically more pronounced for lower-rated and unrated debt obligations (including particularly “junk” or “high yield” bonds), the value of which may fluctuate more significantly in response to poor economic growth or other changes in market conditions, political, economic, legal, and technological developments. Additionally, because the Fund has to accrue income on zero coupon bonds on a current basis even though the Fund does not receive the income from those bonds currently in cash, zero coupon bonds subject the Fund to the risk of having to generate cash from other sources (including through the sale of portfolio securities) in order to make required distributions of the income accrued from its investments in zero coupon bonds. |
| Retail [Member] | Thornburg Summit Fund | Real Estate Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Real Estate Risk – The Fund’s investments in publicly traded real estate investment trusts (“REITs”) are subject to risks affecting real estate investments generally (including market conditions, competition, property obsolescence, changes in interest rates and casualty to real estate), as well as risks specifically affecting REITs (the quality and skill of REIT management and the internal expenses of the REIT). |
| Retail [Member] | Thornburg Summit Fund | Redemption Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Redemption Risk – If a significant percentage of the Fund’s shares is owned or controlled by a single shareholder, the Fund is subject to the risk that a redemption by that shareholder of all or a large portion of its shares may require the Fund to sell securities at less than desired prices, and the Fund’s remaining shareholders may also incur additional transaction costs or adverse tax consequences from such trading activity. |
| Retail [Member] | Thornburg Summit Fund | Risks Affecting Specific Issuers [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Risks Affecting Specific Issuers – The value of an equity security or debt obligation may decline in response to developments affecting the specific issuer of the security or obligation, even if the overall industry or economy is unaffected. These developments may include a variety of factors, including but not limited to management issues or other corporate disruption, a decline in revenues or profitability, an increase in costs, or an adverse effect on the issuer’s competitive position. |
| Retail [Member] | Thornburg Summit Fund | Small and Mid-Cap Company Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Small and Mid-Cap Company Risk – Investments in small capitalization companies and mid-capitalization companies may involve additional risks, which may be relatively higher with smaller companies. These additional risks may result from limited product lines, more limited access to markets and financial resources, greater vulnerability to competition and changes in markets, lack of management depth, increased volatility in share price, and possible difficulty in valuing or selling these investments. |
| Retail [Member] | Thornburg Summit Fund | Depositary Receipts Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Depositary Receipts Risk – An investment in American Depositary Receipts (“ADRs”), European Depositary Receipts (“EDRs”) or Global Depositary Receipts (“GDRs”) is an alternative to the purchase of the underlying securities in their national markets and/or currencies. However, ADRs, EDRs, and GDRs remain subject to many of the risks associated with investing directly in foreign securities, including the political and economic risks associated with the underlying issuer’s country. Certain countries may limit the ability to convert a depositary receipt into the underlying foreign security and vice versa, which may cause the securities of the foreign company to trade at a discount or premium to the market price of the related depositary receipts. Moreover, EDRs and GDRs can involve currency risk since, unlike ADRs, they may not be U.S. dollar denominated. |
| Retail [Member] | Thornburg Summit Fund | Convertible Debt Obligation Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Convertible Debt Obligation Risk – The market value of a convertible debt obligation may vary with changes in prevailing interest rates and changing evaluations of the ability of the issuer to meet principal and interest payments. The market value of a convertible debt obligation may also vary in accordance with the market value of the underlying stock. As a result, convertible debt obligations held by the Fund will tend to perform more like equity securities when the underlying stock price is high (because it is assumed that the Fund will convert the obligation), and more like non-convertible debt obligations when the underlying stock price is low (because it is assumed that the Fund will not convert the obligation). Because its market value can be influenced by several factors, a convertible debt obligation will not be as sensitive to interest rate changes as a similar non-convertible debt obligation, and generally will have less potential for gain or loss than the underlying stock. |
| Retail [Member] | Thornburg Summit Fund | Foreign Government Obligations Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Foreign Government Obligations Risk – Debt obligations may be issued by foreign governments and their agencies and instrumentalities, including the governments of developing countries and “supra-national” entities such as the International Bank for Reconstruction and Development. The Fund’s investments in these foreign debt obligations may be denominated in U.S. dollars or in foreign currencies. These securities, even if denominated in U.S. dollars, may be affected significantly by fluctuations in the value of foreign currencies, and the value of these securities in U.S. dollars may decline even if the securities increase in value in their home country. The governmental issuers of these debt obligations may be less willing or able than the U.S. to repay principal and interest when due, and they may require that the terms for payment be renegotiated. In some countries there may be political instability or insufficient government supervision of markets, and the legal protections for the Fund’s investments could be subject to unfavorable judicial or administrative changes. These risks may be more pronounced for the Fund’s investments in debt obligations issued by developing countries. |
| Retail [Member] | Thornburg Summit Fund | High Yield Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | High Yield Risk – Debt obligations that are rated below investment grade and unrated obligations of similar credit quality (commonly referred to as “junk” or “high yield” bonds) may have a substantial risk of loss. These obligations are generally considered to be speculative with respect to the issuer’s ability to pay interest and principal when due. These obligations may be subject to greater price volatility than investment grade obligations, and their prices may decline significantly in periods of general economic difficulty or in response to adverse publicity, changes in investor perceptions or other factors. These obligations may also be subject to greater liquidity risk. |
| Retail [Member] | Thornburg Summit Fund | Interest Rate Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Interest Rate Risk – When interest rates increase, the value of the Fund’s investments in debt obligations may decline and the Fund’s share value may be reduced. This effect is typically more pronounced for intermediate and longer-term debt obligations. This effect is also typically more pronounced for zero coupon bonds and mortgage- and other asset-backed securities, the value of which may fluctuate more significantly in response to interest rate changes. When interest rates decrease, the Fund’s dividends, if any, may decline. |
| Retail [Member] | Thornburg Summit Fund | Prepayment and Extension Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Prepayment and Extension Risk – When market interest rates decline, certain debt obligations held by the Fund may be repaid more quickly than anticipated, requiring the Fund to reinvest the proceeds of those repayments in obligations which bear a lower interest rate. Conversely, when market interest rates increase, certain debt obligations held by the Fund may be repaid more slowly than anticipated, causing assets of the Fund to remain invested in relatively lower yielding obligations. These risks may be more pronounced for the Fund’s investments in mortgage-backed and asset-backed securities. |
| Retail [Member] | Thornburg Summit Fund | U.S. Government Obligations Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | U.S. Government Obligations Risk – U.S. government obligations are subject to the same risks affecting other debt obligations. Although securities backed by the full faith credit of the U.S. government are commonly regarded as having relatively less risk of default, it is possible that the U.S. government may be unwilling or unable to repay principal and interest when due and may require that the terms for payment be renegotiated. Further obligations that are backed by the full faith and credit of the U.S. government remain subject to the other general risks applicable to debt obligations, such as market risks, liquidity risks, and interest rate risks, and may be subject to ratings downgrades. U.S. government obligations also include obligations of U.S. government agencies, instrumentalities, and government-sponsored enterprises, commonly referred to as “agency obligations.” Some agency obligations are backed by the full faith and credit of the U.S. government, but other agency obligations have no specific backing or only limited support from the agency’s authority to borrow from the U.S. government or the discretionary authority of the Treasury to purchase obligations of the issuing agency. |
| Retail [Member] | Thornburg Summit Fund | Commodities-Related Investment Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Commodities-Related Investment Risk – Investments that expose the Fund to the commodities market, such as commodity-linked derivatives instruments or exchange traded funds or other investment vehicles that invest in commodities, may subject the Fund to greater volatility than investments in other securities. The value of a commodity-related investment may be affected by changes in overall market movements, commodity index volatility, changes in interest rates, risks affecting derivatives when used to obtain commodities exposure, or factors affecting a particular industry or commodity. |
| Retail [Member] | Thornburg Summit Fund | Derivatives Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Derivatives Risk – The Fund’s investments in futures, interest rate swaps, and credit default swaps involve the risks associated with the securities or other assets underlying those derivatives, including the risk of changes in the value of the underlying assets between the date that the Fund enters into the derivatives transaction and the date that the Fund closes out that transaction. The Fund’s investments in futures, interest rate swaps, and credit default swaps also involve the risk that the other party to the transaction will be unable or unwilling to perform its obligations to the Fund, that the Fund will be unable to sell or close its positions in such derivatives or will be delayed in doing so, and that the Fund will have difficulty valuing such derivatives. |
| Retail [Member] | Thornburg Summit Fund | Inflation Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Inflation Risk – Although the Fund seeks to generate capital appreciation and current income that exceeds the rate of inflation over a variety of different market environments, there is no guarantee that the Fund will be able to do so at all times. If at any time the rate of inflation exceeds Thornburg’s expectations, or if for other reasons the Fund’s portfolio is unsuccessful in producing a mix of capital appreciation and current income that exceeds the rate of inflation, the Fund may not achieve its goal. |
| Retail [Member] | Thornburg Summit Fund | Structured Products Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Structured Products Risk – Investments in securities that are backed by, or represent interests in, an underlying pool of securities or other assets, including investments in mortgage- and asset-backed securities and in CMOs, CDOs and CLOS, involve risks associated with the underlying assets (e.g., the risks of default by mortgagors whose mortgages are included in a mortgage-backed security or CMO), and may also involve different or greater risks, including the risk that distributions from the underlying assets will be inadequate to make interest or other payments to the Fund, the risk that the issuer of the securities will fail to administer the underlying assets properly or become insolvent, prepayment and extension risk, and the risk that the securities will be less liquid than other Fund investments. |
| Retail [Member] | Thornburg Summit Fund | Zero Coupon Bonds and Stripped Securities Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Zero Coupon Bonds and Stripped Securities Risk – Zero coupon bonds are corporate or government-issued debt obligations that do not provide for periodic or “coupon” payments of interest, and that are issued at a substantial discount to their face value. The buyer of a zero coupon bond realizes a stated rate of return determined by the gradual accretion in the value of the security. A “stripped” security is a debt obligation that has been transformed into a zero coupon bond by creating a separate, new security comprised of the separate income component of the debt obligation (commonly referred to as an “income only” or “I/O” security) or the separate principal component of the debt obligation (commonly referred to as a “principal only” or “P/O” security). Because zero coupon bonds do not provide for periodic payments of interest, their value is generally more volatile than the value of a comparable, interest-paying bond. The Fund may also have to recognize income on the bond and make distributions to shareholders before it has received any cash payments on the bond. To generate the cash necessary to satisfy such distributions, the Fund may have to sell portfolio securities that it otherwise might have continued to hold or use cash flows from other sources, including the proceeds from the sale of Fund shares. Additional information about Fund investments, investment strategies and risks of investing in the Fund appears below beginning on page 125 of the Prospectus. |
| Retail [Member] | Thornburg Summit Fund | Risk Lose Money [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Accordingly, the loss of money is a risk of investing in the Fund. |
| Retail [Member] | Thornburg Summit Fund | Risk Not Insured [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | An investment in the Fund is not a deposit in any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. |
| Retail [Member] | Thornburg Ultra Short Income Fund | Credit Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Credit Risk – All securities owned by the Fund may be subject to default, delays in payment, adverse legislation or other government action, or could be downgraded by ratings agencies, reducing the value of the Fund’s shares. Securities backed by the full faith and credit of the U.S. government, such as U.S. Treasury obligations, are commonly regarded as having small exposure to credit risk. Obligations of certain U.S. government agencies, instrumentalities and government sponsored enterprises (sometimes referred to as “agency obligations”) are not direct obligations of the United States, may not be backed by the full faith and credit of the U.S. government, and may have a greater exposure to credit risk. Although the U.S. government is required by law to provide credit support for some agency obligations, there is no assurance that the U.S. government would provide financial support for any such obligation on a default by the issuing agency, instrumentality or enterprise in the absence of a legal requirement to do so. As of the date of this Prospectus, securities backed by the U.S. government, and the securities of U.S. government agencies, instrumentalities and enterprises that may be purchased by the Fund are rated “Aaa” by Moody’s Investors Services or “AA+” by S&P Global Ratings. Ratings agencies may reduce the ratings of any securities in the future. |
| Retail [Member] | Thornburg Ultra Short Income Fund | Cybersecurity and Operational Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Cybersecurity and Operational Risk – Operational failures, cyber-attacks or other disruptions that affect the Fund’s service providers, the Fund’s counterparties, other market participants or the issuers of securities held by the Fund may adversely affect the Fund and its shareholders, including by causing losses for the Fund or impairing Fund operations. The rapid development and increasingly widespread use of artificial intelligence, including machine learning technology and generative artificial intelligence such as ChatGPT, could exacerbate these risks. |
| Retail [Member] | Thornburg Ultra Short Income Fund | Foreign Investment Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Foreign Investment Risk – Investments in the debt obligations of foreign issuers may involve risks including adverse fluctuations in currency exchange rates, political instability, confiscations, taxes, or restrictions on currency exchange, difficulty in selling foreign investments, and reduced legal protection. These risks may be more pronounced for investments in developing countries. In addition, some foreign government debt obligations may be subject to default, delays in payment, adverse legislation or government action, or could be downgraded by ratings agencies. |
| Retail [Member] | Thornburg Ultra Short Income Fund | Liquidity Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Liquidity Risk – Due to lack of demand in the marketplace or other factors, the Fund may not be able to sell promptly some or all of the obligations that it holds, or may only be able to sell obligations at less than desired prices. |
| Retail [Member] | Thornburg Ultra Short Income Fund | Management Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Management Risk – The Fund is an actively managed portfolio, and the value of the Fund may be reduced if Thornburg pursues unsuccessful investments or fails to correctly identify risks affecting the broad economy or specific issuers in which the Fund invests. |
| Retail [Member] | Thornburg Ultra Short Income Fund | Market and Economic Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Market and Economic Risk – The value of the Fund’s investments may decline and its share value may be reduced due to changes in general economic and market conditions. For example, a fall in worldwide demand for U.S. government securities or general economic decline could lower the value of those securities. |
| Retail [Member] | Thornburg Ultra Short Income Fund | Redemption Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Redemption Risk – If a significant percentage of the Fund’s shares is owned or controlled by a single shareholder, the Fund is subject to the risk that a redemption by that shareholder of all or a large portion of its shares may require the Fund to sell securities at less than desired prices, and the Fund’s remaining shareholders may also incur additional transaction costs or adverse tax consequences from such trading activity. |
| Retail [Member] | Thornburg Ultra Short Income Fund | Risks Affecting Specific Issuers [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Risks Affecting Specific Issuers – The value of a debt obligation may decline in response to developments affecting the specific issuer of the obligation, even if other issuers or the overall economy are unaffected. These developments may include a variety of factors, including but not limited to management issues or other corporate disruption, a decline in revenues or profitability, an increase in costs, or an adverse effect on the issuer’s competitive position. |
| Retail [Member] | Thornburg Ultra Short Income Fund | Foreign Government Obligations Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Foreign Government Obligations Risk – Debt obligations may be issued by foreign governments and their agencies and instrumentalities, including the governments of developing countries and “supra-national” entities such as the International Bank for Reconstruction and Development. The Fund’s investments in these foreign debt obligations may be denominated in U.S. dollars or in foreign currencies. These securities, even if denominated in U.S. dollars, may be affected significantly by fluctuations in the value of foreign currencies, and the value of these securities in U.S. dollars may decline even if the securities increase in value in their home country. The governmental issuers of these debt obligations may be less willing or able than the U.S. to repay principal and interest when due, and they may require that the terms for payment be renegotiated. In some countries there may be political instability or insufficient government supervision of markets, and the legal protections for the Fund’s investments could be subject to unfavorable judicial or administrative changes. These risks may be more pronounced for the Fund’s investments in debt obligations issued by developing countries. |
| Retail [Member] | Thornburg Ultra Short Income Fund | High Yield Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | High Yield Risk – Debt obligations that are rated below investment grade and unrated obligations of similar credit quality (commonly referred to as “junk” or “high yield” bonds) may have a substantial risk of loss. These obligations are generally considered to be speculative with respect to the issuer’s ability to pay interest and principal when due. These obligations may be subject to greater price volatility than investment grade obligations, and their prices may decline significantly in periods of general economic difficulty or in response to adverse publicity, changes in investor perceptions or other factors. These obligations may also be subject to greater liquidity risk. |
| Retail [Member] | Thornburg Ultra Short Income Fund | Interest Rate Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Interest Rate Risk – When interest rates increase, the value of the Fund’s investments may decline and the Fund’s share value may be reduced. This effect is typically more pronounced for intermediate and longer-term obligations. When interest rates decrease, the Fund’s dividends may decline. |
| Retail [Member] | Thornburg Ultra Short Income Fund | Prepayment and Extension Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Prepayment and Extension Risk – When market interest rates decline, certain debt obligations held by the Fund may be repaid more quickly than anticipated, requiring the Fund to reinvest the proceeds of those repayments in obligations which bear a lower interest rate. Conversely, when market interest rates increase, certain debt obligations held by the Fund may be repaid more slowly than anticipated, causing assets of the Fund to remain invested in relatively lower yielding obligations. These risks may be more pronounced for the Fund’s investments in mortgage-backed and asset-backed securities. |
| Retail [Member] | Thornburg Ultra Short Income Fund | U.S. Government Obligations Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | U.S. Government Obligations Risk – U.S. government obligations are subject to the same risks affecting other debt obligations. Although securities backed by the full faith credit of the U.S. government are commonly regarded as having relatively less risk of default, it is possible that the U.S. government may be unwilling or unable to repay principal and interest when due and may require that the terms for payment be renegotiated. Further obligations that are backed by the full faith and credit of the U.S. government remain subject to the other general risks applicable to debt obligations, such as market risks, liquidity risks, and interest rate risks, and may be subject to ratings downgrades. U.S. government obligations also include obligations of U.S. government agencies, instrumentalities, and government-sponsored enterprises, commonly referred to as “agency obligations.” Some agency obligations are backed by the full faith and credit of the U.S. government, but other agency obligations have no specific backing or only limited support from the agency’s authority to borrow from the U.S. government or the discretionary authority of the Treasury to purchase obligations of the issuing agency. Additional information about Fund investments, investment strategies and risks of investing in the Fund appears beginning on page 125 of the Prospectus. |
| Retail [Member] | Thornburg Ultra Short Income Fund | Structured Products Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Structured Products Risk – Investments in securities that are backed by, or represent interests in, an underlying pool of securities or other assets, including investments in mortgage- and asset-backed securities and in collateralized mortgage obligations and collateralized debt obligations, involve the risks associated with the underlying assets (e.g., the risk of default by mortgagors whose mortgages are included in a mortgage-backed security or collateralized mortgage obligation), and may also involve the risk that distributions from the underlying assets will be inadequate to make interest or other payments to the Fund, the risk that the issuer of the securities will fail to administer the underlying assets properly or become insolvent, and the risk that the securities will be less liquid than other Fund investments. |
| Retail [Member] | Thornburg Ultra Short Income Fund | Risk Lose Money [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Accordingly, the loss of money is a risk of investing in the Fund. |
| Retail [Member] | Thornburg Ultra Short Income Fund | Risk Not Insured [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | An investment in the Fund is not a deposit in any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. |
| Retail [Member] | Thornburg Limited Term U.S. Government Fund | Credit Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Credit Risk – All securities owned by the Fund may be subject to default, delays in payment, adverse legislation or other government action, or could be downgraded by ratings agencies, reducing the value of the Fund’s shares. Securities backed by the full faith and credit of the U.S. government, such as U.S. Treasury obligations, are commonly regarded as having small exposure to credit risk. Obligations of certain U.S. government agencies, instrumentalities and government-sponsored enterprises (sometimes referred to as “agency obligations”) are not direct obligations of the United States, may not be backed by the full faith and credit of the U.S. government, and may have a greater exposure to credit risk. Although the U.S. government is required by law to provide credit support for some agency obligations, there is no assurance that the U.S. government would provide financial support for any such obligation on a default by the issuing agency, instrumentality or enterprise in the absence of a legal requirement to do so. As of the date of this Prospectus, securities backed by the full faith and credit of the U.S. government, and securities of U.S. government agencies, instrumentalities and enterprises which may be purchased by the Fund are rated “Aaa” by Moody’s Investors Services or “AA+” by S&P Global Ratings. Ratings agencies may reduce the ratings of any securities in the future. |
| Retail [Member] | Thornburg Limited Term U.S. Government Fund | Cybersecurity and Operational Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Cybersecurity and Operational Risk – Operational failures, cyber-attacks or other disruptions that affect the Fund’s service providers, the Fund’s counterparties, other market participants or the issuers of securities held by the Fund may adversely affect the Fund and its shareholders, including by causing losses for the Fund or impairing Fund operations. The rapid development and increasingly widespread use of artificial intelligence, including machine learning technology and generative artificial intelligence such as ChatGPT, could exacerbate these risks. |
| Retail [Member] | Thornburg Limited Term U.S. Government Fund | Liquidity Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Liquidity Risk – Due to a lack of demand in the marketplace or other factors, the Fund may not be able to sell promptly some or all of the obligations that it holds, or may only be able to sell obligations at less than desired prices. |
| Retail [Member] | Thornburg Limited Term U.S. Government Fund | Management Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Management Risk – The Fund is an actively managed portfolio, and the value of the Fund may be reduced if Thornburg pursues unsuccessful investments or fails to correctly identify risks affecting the broad economy or specific issuers in which the Fund invests. |
| Retail [Member] | Thornburg Limited Term U.S. Government Fund | Market and Economic Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Market and Economic Risk – The value of the Fund’s investments may decline and its share value may be reduced due to changes in general economic and market conditions. For example, a fall in worldwide demand for U.S. government securities or general economic decline could lower the value of those securities. |
| Retail [Member] | Thornburg Limited Term U.S. Government Fund | Redemption Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Redemption Risk – If a significant percentage of the Fund’s shares is owned or controlled by a single shareholder, the Fund is subject to the risk that a redemption by that shareholder of all or a large portion of its shares may require the Fund to sell securities at less than desired prices, and the Fund’s remaining shareholders may also incur additional transaction costs or adverse tax consequences from such trading activity. |
| Retail [Member] | Thornburg Limited Term U.S. Government Fund | Interest Rate Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Interest Rate Risk – When interest rates increase, the value of the Fund’s investments may decline and the Fund’s share value may be reduced. This effect is typically more pronounced for intermediate and longer-term obligations. This effect is also typically more pronounced for the Fund’s investment in mortgage-backed securities, the value of which may fluctuate more significantly in response to interest rate changes. When interest rates decrease, the Fund’s dividends may decline. |
| Retail [Member] | Thornburg Limited Term U.S. Government Fund | Prepayment and Extension Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Prepayment and Extension Risk – When market interest rates decline, certain debt obligations held by the Fund may be repaid more quickly than anticipated, requiring the Fund to reinvest the proceeds of those repayments in obligations which bear a lower interest rate. Conversely, when market interest rates increase, certain debt obligations held by the Fund may be repaid more slowly than anticipated, causing assets of the Fund to remain invested in relatively lower yielding obligations. These risks may be more pronounced for the Fund’s investments in mortgage-backed securities. |
| Retail [Member] | Thornburg Limited Term U.S. Government Fund | U.S. Government Obligations Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | U.S. Government Obligations Risk – U.S. government obligations are subject to the same risks affecting other debt obligations. Although securities backed by the full faith credit of the U.S. government are commonly regarded as having relatively less risk of default, it is possible that the U.S. government may be unwilling or unable to repay principal and interest when due and may require that the terms for payment be renegotiated. Further obligations that are backed by the full faith and credit of the U.S. government remain subject to the other general risks applicable to debt obligations, such as market risks, liquidity risks, and interest rate risks, and may be subject to ratings downgrades. U.S. government obligations also include obligations of U.S. government agencies, instrumentalities, and government-sponsored enterprises, commonly referred to as “agency obligations.” Some agency obligations are backed by the full faith and credit of the U.S. government, but other agency obligations have no specific backing or only limited support from the agency’s authority to borrow from the U.S. government or the discretionary authority of the Treasury to purchase obligations of the issuing agency. Additional information about Fund investments, investment strategies, and risks of investing in the Fund appears below beginning on page 125 of the Prospectus. |
| Retail [Member] | Thornburg Limited Term U.S. Government Fund | Structured Products Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Structured Products Risk – Investments in securities that are backed by, or represent interests in, an underlying pool of securities or other assets, including investments in mortgage-backed securities and in CMOs, involve the risks associated with the underlying assets (e.g., the risk of default by mortgagors whose mortgages are included in a mortgage-backed security or CMO), and may also involve different or greater risks, including the risk that distributions from the underlying assets will be inadequate to make interest or other payments to the Fund, the risk that the issuer of the securities will fail to administer the underlying assets properly or become insolvent, and the risk that the securities will be less liquid than other Fund investments. |
| Retail [Member] | Thornburg Limited Term U.S. Government Fund | Risk Lose Money [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Accordingly, the loss of money is a risk of investing in the Fund. |
| Retail [Member] | Thornburg Limited Term U.S. Government Fund | Risk Not Insured [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | An investment in the Fund is not a deposit in any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. |
| Retail [Member] | Thornburg Limited Term Income Fund | Credit Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Credit Risk – All securities owned by the Fund may be subject to default, delays in payment, adverse legislation or other government action, or could be downgraded by ratings agencies, reducing the value of the Fund’s shares. Securities backed by the full faith and credit of the U.S. government, such as U.S. Treasury obligations, are commonly regarded as having small exposure to credit risk. Obligations of certain U.S. government agencies, instrumentalities and government sponsored enterprises (sometimes referred to as “agency obligations”) are not direct obligations of the United States, may not be backed by the full faith and credit of the U.S. government, and may have a greater exposure to credit risk. Although the U.S. government is required by law to provide credit support for some agency obligations, there is no assurance that the U.S. government would provide financial support for any such obligation on a default by the issuing agency, instrumentality or enterprise in the absence of a legal requirement to do so. As of the date of this Prospectus, securities backed by the full faith and credit of the U.S. government, and securities of U.S. government agencies, instrumentalities and enterprises which may be purchased by the Fund, are rated “Aaa” by Moody’s Investors Services or “AA+” by S&P Global Ratings. Ratings agencies may reduce the ratings of any securities in the future. Lower-rated or unrated obligations in which the Fund is permitted to invest may have, or may be perceived to have, greater risk of default and ratings downgrades. |
| Retail [Member] | Thornburg Limited Term Income Fund | Cybersecurity and Operational Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Cybersecurity and Operational Risk – Operational failures, cyber-attacks or other disruptions that affect the Fund’s service providers, the Fund’s counterparties, other market participants or the issuers of securities held by the Fund may adversely affect the Fund and its shareholders, including by causing losses for the Fund or impairing Fund operations. The rapid development and increasingly widespread use of artificial intelligence, including machine learning technology and generative artificial intelligence such as ChatGPT, could exacerbate these risks. |
| Retail [Member] | Thornburg Limited Term Income Fund | Foreign Investment Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Foreign Investment Risk – Investments in the debt obligations of foreign issuers may involve risks including adverse fluctuations in currency exchange rates, political instability, confiscations, taxes or restrictions on currency exchange, difficulty in selling foreign investments, and reduced legal protection. These risks may be more pronounced for investments in developing countries. In addition, some foreign government debt obligations may be subject to default, delays in payment, adverse legislation or government action, or could be downgraded by ratings agencies. |
| Retail [Member] | Thornburg Limited Term Income Fund | Liquidity Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Liquidity Risk – Due to a lack of demand in the marketplace or other factors, the Fund may not be able to sell promptly some or all of the obligations that it holds, or may only be able to sell obligations at less than desired prices. |
| Retail [Member] | Thornburg Limited Term Income Fund | Management Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Management Risk – The Fund is an actively managed portfolio, and the value of the Fund may be reduced if Thornburg pursues unsuccessful investments or fails to correctly identify risks affecting the broad economy or specific issuers in which the Fund invests. |
| Retail [Member] | Thornburg Limited Term Income Fund | Market and Economic Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Market and Economic Risk – The value of the Fund’s investments may decline and its share value may be reduced due to changes in general economic and market conditions. For example, a fall in worldwide demand for U.S. government securities or general economic decline could lower the value of those securities. |
| Retail [Member] | Thornburg Limited Term Income Fund | Redemption Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Redemption Risk – If a significant percentage of the Fund’s shares is owned or controlled by a single shareholder, the Fund is subject to the risk that a redemption by that shareholder of all or a large portion of its shares may require the Fund to sell securities at less than desired prices, and the Fund’s remaining shareholders may also incur additional transaction costs or adverse tax consequences from such trading activity. |
| Retail [Member] | Thornburg Limited Term Income Fund | Risks Affecting Specific Issuers [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Risks Affecting Specific Issuers – The value of a debt obligation may decline in response to developments affecting the specific issuer of the obligation, even if other issuers or the overall economy are unaffected. These developments may include a variety of factors, including but not limited to management issues or other corporate disruption, a decline in revenues or profitability, an increase in costs, or an adverse effect on the issuer’s competitive position. |
| Retail [Member] | Thornburg Limited Term Income Fund | Foreign Government Obligations Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Foreign Government Obligations Risk – Debt obligations may be issued by foreign governments and their agencies and instrumentalities, including the governments of developing countries and “supra-national” entities such as the International Bank for Reconstruction and Development. The Fund’s investments in these foreign debt obligations may be denominated in U.S. dollars or in foreign currencies. These securities, even if denominated in U.S. dollars, may be affected significantly by fluctuations in the value of foreign currencies, and the value of these securities in U.S. dollars may decline even if the securities increase in value in their home country. The governmental issuers of these debt obligations may be less willing or able than the U.S. to repay principal and interest when due, and they may require that the terms for payment be renegotiated. In some countries there may be political instability or insufficient government supervision of markets, and the legal protections for the Fund’s investments could be subject to unfavorable judicial or administrative changes. These risks may be more pronounced for the Fund’s investments in debt obligations issued by developing countries. |
| Retail [Member] | Thornburg Limited Term Income Fund | Interest Rate Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Interest Rate Risk – When interest rates increase, the value of the Fund’s investments may decline and the Fund’s share value may be reduced. This effect is typically more pronounced for intermediate and longer-term obligations. This effect is also typically more pronounced for the Fund’s investment in mortgage- and other asset-backed securities, the value of which may fluctuate more significant in response to interest rate changes. When interest rates decrease, the Fund’s dividends may decline. |
| Retail [Member] | Thornburg Limited Term Income Fund | Prepayment and Extension Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Prepayment and Extension Risk – When market interest rates decline, certain debt obligations held by the Fund may be repaid more quickly than anticipated, requiring the Fund to reinvest the proceeds of those repayments in obligations which bear a lower interest rate. Conversely, when market interest rates increase, certain debt obligations held by the Fund may be repaid more slowly than anticipated, causing assets of the Fund to remain invested in relatively lower yielding obligations. These risks may be more pronounced for the Fund’s investments in mortgage-backed and asset-backed securities. |
| Retail [Member] | Thornburg Limited Term Income Fund | U.S. Government Obligations Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | U.S. Government Obligations Risk – U.S. government obligations are subject to the same risks affecting other debt obligations. Although securities backed by the full faith credit of the U.S. government are commonly regarded as having relatively less risk of default, it is possible that the U.S. government may be unwilling or unable to repay principal and interest when due and may require that the terms for payment be renegotiated. Further obligations that are backed by the full faith and credit of the U.S. government remain subject to the other general risks applicable to debt obligations, such as market risks, liquidity risks, and interest rate risks, and may be subject to ratings downgrades. U.S. government obligations also include obligations of U.S. government agencies, instrumentalities, and government-sponsored enterprises, commonly referred to as “agency obligations.” Some agency obligations are backed by the full faith and credit of the U.S. government, but other agency obligations have no specific backing or only limited support from the agency’s authority to borrow from the U.S. government or the discretionary authority of the Treasury to purchase obligations of the issuing agency. Additional information about Fund investments, investment strategies, and risks of investing in the Fund appears below beginning on page 125 of the Prospectus. |
| Retail [Member] | Thornburg Limited Term Income Fund | Structured Products Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Structured Products Risk – Investments in securities that are backed by, or represent interests in, an underlying pool of securities or other assets, including investments in mortgage- and asset-backed securities and in collateralized mortgage obligations and collateralized debt obligations, involve the risks associated with the underlying assets (e.g., the risk of default by mortgagors whose mortgages are included in a mortgage-backed security or collateralized mortgage obligation), and may also involve different or greater risks, including the risk that distributions from the underlying assets will be inadequate to make interest or other payments to the Fund, the risk that the issuer of the securities will fail to administer the underlying assets properly or become insolvent, and the risk that the securities will be less liquid than other Fund investments. |
| Retail [Member] | Thornburg Limited Term Income Fund | Risk Lose Money [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Accordingly, the loss of money is a risk of investing in the Fund. |
| Retail [Member] | Thornburg Limited Term Income Fund | Risk Not Insured [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | An investment in the Fund is not a deposit in any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. |
| Retail [Member] | Thornburg Core Plus Bond Fund | Credit Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Credit Risk – If obligations held by the Fund are downgraded by ratings agencies or go into default, or if management action, legislation or other government action reduces the ability of issuers to pay principal and interest when due, the value of those obligations may decline and the Fund’s share value and the dividends paid by the Fund may be reduced. Because the ability of an issuer of a lower-rated or unrated obligation to pay principal and interest when due is typically less certain than for an issuer of a higher-rated obligation, lower-rated and unrated obligations are generally more vulnerable than higher- rated obligations to default, to ratings downgrades, and to liquidity risk. Debt obligations backed by so-called “subprime” mortgages may also be subject to a greater risk of default or downgrade. Debt obligations issued by the U.S. government or its agencies, instrumentalities and government sponsored enterprises are also subject to credit risk. Securities backed by the full faith and credit of the U.S. government, such as U.S. Treasury obligations, are commonly regarded as having small exposure to credit risk. Obligations of certain U.S. agencies, instrumentalities and enterprises (sometimes referred to as “agency obligations”) are not direct obligations of the U.S. government, may not be backed by the full faith and credit of the U.S. government, and may have a greater exposure to credit risk. |
| Retail [Member] | Thornburg Core Plus Bond Fund | Cybersecurity and Operational Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Cybersecurity and Operational Risk – Operational failures, cyber-attacks or other disruptions that affect the Fund’s service providers, the Fund’s counterparties, other market participants, or the issuers of securities held by the Fund may adversely affect the Fund and its shareholders, including by causing losses for the Fund or impairing Fund operations. The rapid development and increasingly widespread use of artificial intelligence, including machine learning technology and generative artificial intelligence such as ChatGPT, could exacerbate these risks. |
| Retail [Member] | Thornburg Core Plus Bond Fund | Foreign Currency Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Foreign Currency Risk – Fluctuations in currency exchange rates can adversely affect the value of the Fund’s foreign investments. Such fluctuations may occur for a number of reasons, including market and economic conditions, or a government’s decision to devalue its currency or impose currency controls. |
| Retail [Member] | Thornburg Core Plus Bond Fund | Foreign Investment Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Foreign Investment Risk – Investments in the debt obligations of foreign issuers may involve risks including adverse fluctuations in currency exchange rates, political instability, confiscations, taxes or restrictions on currency exchange, difficulty in selling foreign investments, and reduced legal protection. In addition, some foreign government debt obligations may be subject to default, delays in payment, adverse legislation or government action, or could be downgraded by ratings agencies. |
| Retail [Member] | Thornburg Core Plus Bond Fund | Liquidity Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Liquidity Risk – Due to a lack of demand in the marketplace or other factors, the Fund may not be able to sell some or all of its investments promptly, or may only be able to sell investments at less than desired prices. The market for lower-rated and unrated debt obligations (including particularly “junk” or “high yield” bonds) and debt obligations backed by so-called “subprime” mortgages may be less liquid than the market for other obligations, making it difficult for the Fund to value its investment in a lower-rated or unrated obligation or to sell the investment in a timely manner or at an acceptable price. |
| Retail [Member] | Thornburg Core Plus Bond Fund | Management Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Management Risk – The Fund is an actively managed portfolio, and the value of the Fund may be reduced if Thornburg pursues unsuccessful investments or fails to correctly identify risks affecting the broad economy or specific issuers in which the Fund invests. |
| Retail [Member] | Thornburg Core Plus Bond Fund | Market and Economic Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Market and Economic Risk – The value of the Fund’s investments may decline and its share value may be reduced due to changes in general economic and market conditions. This effect is typically more pronounced for lower-rated and unrated debt obligations (including particularly “junk” or “high yield” bonds), the value of which may fluctuate more significantly in response to poor economic growth or other changes in market conditions, political, economic, legal, and technological developments, and developments affecting specific issuers. |
| Retail [Member] | Thornburg Core Plus Bond Fund | Redemption Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Redemption Risk – If a significant percentage of the Fund’s shares is owned or controlled by a single shareholder, the Fund is subject to the risk that a redemption by that shareholder of all or a large portion of its shares may require the Fund to sell securities at less than desired prices, and the Fund’s remaining shareholders may also incur additional transaction costs or adverse tax consequences from such trading activity. |
| Retail [Member] | Thornburg Core Plus Bond Fund | Risks Affecting Specific Issuers [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Risks Affecting Specific Issuers – The value of a debt obligation may decline in response to developments affecting the specific issuer of the obligation or security, even if the overall industry or economy is unaffected. These developments may include a variety of factors, including but not limited to management issues or other corporate disruption, a decline in revenues or profitability, an increase in costs, or an adverse effect on the issuer’s competitive position. |
| Retail [Member] | Thornburg Core Plus Bond Fund | Small and Mid-Cap Company Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Small and Mid-Cap Company Risk – Debt obligations of small-capitalization companies and mid-capitalization companies may involve additional risks, which may be relatively higher with smaller companies. These additional risks may result from limited product lines, more limited access to markets and financial resources, greater vulnerability to competition and changes in markets, lack of management depth, increased volatility, and possible difficulties in valuing or selling these investments. |
| Retail [Member] | Thornburg Core Plus Bond Fund | Foreign Government Obligations Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Foreign Government Obligations Risk – Debt obligations may be issued by foreign governments and their agencies and instrumentalities, including the governments of developing countries and “supra-national” entities such as the International Bank for Reconstruction and Development. The Fund’s investments in these foreign debt obligations may be denominated in U.S. dollars or in foreign currencies. These securities, even if denominated in U.S. dollars, may be affected significantly by fluctuations in the value of foreign currencies, and the value of these securities in U.S. dollars may decline even if the securities increase in value in their home country. The governmental issuers of these debt obligations may be less willing or able than the U.S. to repay principal and interest when due, and they may require that the terms for payment be renegotiated. In some countries there may be political instability or insufficient government supervision of markets, and the legal protections for the Fund’s investments could be subject to unfavorable judicial or administrative changes. These risks may be more pronounced for the Fund’s investments in debt obligations issued by developing countries. |
| Retail [Member] | Thornburg Core Plus Bond Fund | High Yield Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | High Yield Risk – Debt obligations that are rated below investment grade and unrated obligations of similar credit quality (commonly referred to as “junk” or “high yield” bonds) may have a substantial risk of loss. These obligations are generally considered to be speculative with respect to the issuer’s ability to pay interest and principal when due. These obligations may be subject to greater price volatility than investment grade obligations, and their prices may decline significantly in periods of general economic difficulty or in response to adverse publicity, changes in investor perceptions or other factors. These obligations may also be subject to greater liquidity risk. |
| Retail [Member] | Thornburg Core Plus Bond Fund | Interest Rate Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Interest Rate Risk – When interest rates increase, the value of the Fund’s investments may decline and the Fund’s share value may be reduced. This effect is typically more pronounced for intermediate and longer-term obligations. This effect is also typically more pronounced for mortgage- and other asset-backed securities, the value of which may fluctuate more significantly in response to interest rate changes. When interest rates decrease, the Fund’s dividends may decline. |
| Retail [Member] | Thornburg Core Plus Bond Fund | Prepayment and Extension Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Prepayment and Extension Risk – When market interest rates decline, certain debt obligations held by the Fund may be repaid more quickly than anticipated, requiring the Fund to reinvest the proceeds of those repayments in obligations which bear a lower interest rate. Conversely, when market interest rates increase, certain debt obligations held by the Fund may be repaid more slowly than anticipated, causing assets of the Fund to remain invested in relatively lower yielding obligations. These risks may be more pronounced for the Fund’s investments in mortgage-backed and asset-backed securities. |
| Retail [Member] | Thornburg Core Plus Bond Fund | U.S. Government Obligations Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | U.S. Government Obligations Risk – U.S. government obligations are subject to the same risks affecting other debt obligations. Although securities backed by the full faith credit of the U.S. government are commonly regarded as having relatively less risk of default, it is possible that the U.S. government may be unwilling or unable to repay principal and interest when due and may require that the terms for payment be renegotiated. Further obligations that are backed by the full faith and credit of the U.S. government remain subject to the other general risks applicable to debt obligations, such as market risks, liquidity risks, and interest rate risks, and may be subject to ratings downgrades. U.S. government obligations also include obligations of U.S. government agencies, instrumentalities, and government-sponsored enterprises, commonly referred to as “agency obligations.” Some agency obligations are backed by the full faith and credit of the U.S. government, but other agency obligations have no specific backing or only limited support from the agency’s authority to borrow from the U.S. government or the discretionary authority of the Treasury to purchase obligations of the issuing agency. Additional information about Fund investments, investment strategies and risks of investing in the Fund appears below beginning on page 125. |
| Retail [Member] | Thornburg Core Plus Bond Fund | Derivatives Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Derivatives Risk – The Fund’s investments in futures contracts, options, swaps, forward contracts, and other derivative instruments involve the risks associated with the securities or other assets underlying those derivatives, and also may involve risks different or greater than the risks affecting the underlying assets, including the inability or unwillingness of the other party to a derivative to perform its obligations to the Fund, the Fund’s inability or delays in selling or closing positions in derivatives, and difficulties in valuing derivatives. |
| Retail [Member] | Thornburg Core Plus Bond Fund | Structured Products Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Structured Products Risk – Investments in securities that are backed by, or represent interests in, an underlying pool of securities or other assets, including investments in mortgage- and asset-backed securities and in collateralized mortgage obligations, involve the risks associated with the underlying assets (e.g., the risk of default by mortgagors whose mortgages are included in a mortgage-backed security or collateralized mortgage obligation), and may also involve different or greater risks, including the risk that distributions from the underlying assets will be inadequate to make interest or other payments to the Fund, the risk that the issuer of the securities will fail to administer the underlying assets properly or become insolvent, and the risk that the securities will be less liquid than other Fund investments. |
| Retail [Member] | Thornburg Core Plus Bond Fund | Emerging Markets Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Emerging Markets Risk – The risks which may affect investments in foreign issuers (see “Foreign Investment Risk,” below) may be more pronounced for investments in emerging markets, also known as developing countries, because the economies of those markets are usually less diversified, communications, transportation and economic infrastructures are less developed, and emerging markets ordinarily have less established legal, political, business and social frameworks. At times the prices of debt obligations of an issuer in an emerging market may be extremely volatile. An issuer in a developed country may be similarly affected by these emerging markets risks to the extent that the issuer conducts its business in emerging markets. |
| Retail [Member] | Thornburg Core Plus Bond Fund | Risk Lose Money [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Accordingly, the loss of money is a risk of investing in the Fund. |
| Retail [Member] | Thornburg Core Plus Bond Fund | Risk Not Insured [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | An investment in the Fund is not a deposit in any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. |
| Retail [Member] | Thornburg Strategic Income Fund | Credit Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Credit Risk – If obligations held by the Fund are downgraded by ratings agencies or go into default, or if management action, legislation or other government action reduces the ability of issuers to pay principal and interest when due, the value of those obligations may decline and the Fund’s share value and the dividends paid by the Fund may be reduced. Because the ability of an issuer of a lower-rated or unrated obligation to pay principal and interest when due is typically less certain than for an issuer of a higher-rated obligation, lower-rated and unrated obligations are generally more vulnerable than higher- rated obligations to default, to ratings downgrades, and to liquidity risk. Debt obligations backed by so-called “subprime” mortgages may also be subject to a greater risk of default or downgrade. Debt obligations issued by the U.S. government or its agencies, instrumentalities and government sponsored enterprises are also subject to credit risk. Securities backed by the full faith and credit of the U.S. government, such as U.S. Treasury obligations, are commonly regarded as having small exposure to credit risk. Obligations of certain U.S. agencies, instrumentalities and enterprises (sometimes referred to as “agency obligations”) are not direct obligations of the U.S. government, may not be backed by the full faith and credit of the U.S. government, and may have a greater exposure to credit risk. |
| Retail [Member] | Thornburg Strategic Income Fund | Cybersecurity and Operational Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Cybersecurity and Operational Risk – Operational failures, cyber-attacks or other disruptions that affect the Fund’s service providers, the Fund’s counterparties, other market participants or the issuers of securities held by the Fund may adversely affect the Fund and its shareholders, including by causing losses for the Fund or impairing Fund operations. The rapid development and increasingly widespread use of artificial intelligence, including machine learning technology and generative artificial intelligence such as ChatGPT, could exacerbate these risks. |
| Retail [Member] | Thornburg Strategic Income Fund | Developing Country Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Developing Country Risk – The risks which may affect investments in foreign issuers (see “Foreign Investment Risk,” below) may be more pronounced for investments in developing countries because the economies of those countries are usually less diversified, communications, transportation and economic infrastructures are less developed, and developing countries ordinarily have less established legal, political, business and social frameworks. At times the prices of debt obligations of a developing country issuer may be extremely volatile. An issuer domiciled in a developed country may be similarly affected by these developing country risks to the extent that the issuer conducts its business in developing countries. |
| Retail [Member] | Thornburg Strategic Income Fund | Foreign Currency Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Foreign Currency Risk – Fluctuations in currency exchange rates can adversely affect the value of the Fund’s foreign investments. Such fluctuations may occur for a number of reasons, including market and economic conditions, or a government’s decision to devalue its currency or impose currency controls. |
| Retail [Member] | Thornburg Strategic Income Fund | Foreign Investment Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Foreign Investment Risk – Investments in the debt obligations of foreign issuers may involve risks including adverse fluctuations in currency exchange rates, political instability, confiscations, taxes or restrictions on currency exchange, difficulty in selling foreign investments, and reduced legal protection. In addition, some foreign government debt obligations may be subject to default, delays in payment, adverse legislation or government action, or could be downgraded by ratings agencies. |
| Retail [Member] | Thornburg Strategic Income Fund | Liquidity Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Liquidity Risk – Due to a lack of demand in the marketplace or other factors, the Fund may not be able to sell some or all of its investments promptly, or may only be able to sell investments at less than desired prices. The market for lower-rated and unrated debt obligations (including particularly “junk” or “high yield” bonds) and debt obligations backed by so-called “subprime” mortgages may be less liquid than the market for other obligations, making it difficult for the Fund to value its investment in a lower-rated or unrated obligation or to sell the investment in a timely manner or at an acceptable price. |
| Retail [Member] | Thornburg Strategic Income Fund | Management Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Management Risk – The Fund is an actively managed portfolio, and the value of the Fund may be reduced if Thornburg pursues unsuccessful investments or fails to correctly identify risks affecting the broad economy or specific issuers in which the Fund invests. |
| Retail [Member] | Thornburg Strategic Income Fund | Market and Economic Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Market and Economic Risk – The value of the Fund’s investments may decline and its share value may be reduced due to changes in general economic and market conditions. This effect is typically more pronounced for lower-rated and unrated debt obligations (including particularly “junk” or “high yield” bonds), the value of which may fluctuate more significantly in response to poor economic growth or other changes in market conditions, political, economic, legal, and technological developments. The market value of any zero coupon bonds or “stripped” securities that the Fund may purchase will typically be more volatile than the value of a comparable, interest-paying bond. Additionally, zero coupon bonds and “stripped” securities are subject to the risk that the Fund may have to recognize income on its investment and make distributions to shareholders before it has received any cash payments on its investment. |
| Retail [Member] | Thornburg Strategic Income Fund | Redemption Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Redemption Risk – If a significant percentage of the Fund’s shares is owned or controlled by a single shareholder, the Fund is subject to the risk that a redemption by that shareholder of all or a large portion of its shares may require the Fund to sell securities at less than desired prices, and the Fund’s remaining shareholders may also incur additional transaction costs or adverse tax consequences from such trading activity. |
| Retail [Member] | Thornburg Strategic Income Fund | Risks Affecting Specific Issuers [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Risks Affecting Specific Issuers – The value of a debt obligation may decline in response to developments affecting the specific issuer of the obligation or security, even if the overall industry or economy is unaffected. These developments may include a variety of factors, including but not limited to management issues or other corporate disruption, a decline in revenues or profitability, an increase in costs, or an adverse effect on the issuer’s competitive position. |
| Retail [Member] | Thornburg Strategic Income Fund | Small and Mid-Cap Company Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Small and Mid-Cap Company Risk – Investments in small-capitalization companies and mid-capitalization companies may involve additional risks, which may be relatively higher with smaller companies. These additional risks may result from limited product lines, more limited access to markets and financial resources, greater vulnerability to competition and changes in markets, lack of management depth, increased volatility in share price, and possible difficulties in valuing or selling these investments. |
| Retail [Member] | Thornburg Strategic Income Fund | Convertible Debt Obligation Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Convertible Debt Obligation Risk – The market value of a convertible debt obligation may vary with changes in prevailing interest rates and changing evaluations of the ability of the issuer to meet principal and interest payments. The market value of a convertible debt obligation may also vary in accordance with the market value of the underlying stock. As a result, convertible debt obligations held by the Fund will tend to perform more like equity securities when the underlying stock price is high (because it is assumed that the Fund will convert the obligation), and more like non-convertible debt obligations when the underlying stock price is low (because it is assumed that the Fund will not convert the obligation). Because its market value can be influenced by several factors, a convertible debt obligation will not be as sensitive to interest rate changes as a similar non-convertible debt obligation, and generally will have less potential for gain or loss than the underlying stock. |
| Retail [Member] | Thornburg Strategic Income Fund | Foreign Government Obligations Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Foreign Government Obligations Risk – Debt obligations may be issued by foreign governments and their agencies and instrumentalities, including the governments of developing countries and “supra-national” entities such as the International Bank for Reconstruction and Development. The Fund’s investments in these foreign debt obligations may be denominated in U.S. dollars or in foreign currencies. These securities, even if denominated in U.S. dollars, may be affected significantly by fluctuations in the value of foreign currencies, and the value of these securities in U.S. dollars may decline even if the securities increase in value in their home country. The governmental issuers of these debt obligations may be less willing or able than the U.S. to repay principal and interest when due, and they may require that the terms for payment be renegotiated. In some countries there may be political instability or insufficient government supervision of markets, and the legal protections for the Fund’s investments could be subject to unfavorable judicial or administrative changes. These risks may be more pronounced for the Fund’s investments in debt obligations issued by developing countries. |
| Retail [Member] | Thornburg Strategic Income Fund | High Yield Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | High Yield Risk – Debt obligations that are rated below investment grade and unrated obligations of similar credit quality (commonly referred to as “junk” or “high yield” bonds) may have a substantial risk of loss. These obligations are generally considered to be speculative with respect to the issuer’s ability to pay interest and principal when due. These obligations may be subject to greater price volatility than investment grade obligations, and their prices may decline significantly in periods of general economic difficulty or in response to adverse publicity, changes in investor perceptions or other factors. These obligations may also be subject to greater liquidity risk. |
| Retail [Member] | Thornburg Strategic Income Fund | Interest Rate Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Interest Rate Risk – When interest rates increase, the value of the Fund’s investments may decline and the Fund’s share value may be reduced. This effect is typically more pronounced for intermediate and longer-term obligations. This effect is also typically more pronounced for mortgage- and other asset-backed securities, the value of which may fluctuate more significantly in response to interest rate changes. When interest rates decrease, the Fund’s dividends may decline. |
| Retail [Member] | Thornburg Strategic Income Fund | Prepayment and Extension Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Prepayment and Extension Risk – When market interest rates decline, certain debt obligations held by the Fund may be repaid more quickly than anticipated, requiring the Fund to reinvest the proceeds of those repayments in obligations which bear a lower interest rate. Conversely, when market interest rates increase, certain debt obligations held by the Fund may be repaid more slowly than anticipated, causing assets of the Fund to remain invested in relatively lower yielding obligations. These risks may be more pronounced for the Fund’s investments in mortgage-backed and asset-backed securities. |
| Retail [Member] | Thornburg Strategic Income Fund | U.S. Government Obligations Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | U.S. Government Obligations Risk – U.S. government obligations are subject to the same risks affecting other debt obligations. Although securities backed by the full faith credit of the U.S. government are commonly regarded as having relatively less risk of default, it is possible that the U.S. government may be unwilling or unable to repay principal and interest when due and may require that the terms for payment be renegotiated. Further obligations that are backed by the full faith and credit of the U.S. government remain subject to the other general risks applicable to debt obligations, such as market risks, liquidity risks, and interest rate risks, and may be subject to ratings downgrades. U.S. government obligations also include obligations of U.S. government agencies, instrumentalities, and government-sponsored enterprises, commonly referred to as “agency obligations.” Some agency obligations are backed by the full faith and credit of the U.S. government, but other agency obligations have no specific backing or only limited support from the agency’s authority to borrow from the U.S. government or the discretionary authority of the Treasury to purchase obligations of the issuing agency. |
| Retail [Member] | Thornburg Strategic Income Fund | Structured Products Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Structured Products Risk – Investments in securities that are backed by, or represent interests in, an underlying pool of securities or other assets, including investments in mortgage- and asset-backed securities and in collateralized mortgage obligations and collateralized debt obligations, involve the risks associated with the underlying assets (e.g., the risk of default by mortgagors whose mortgages are included in a mortgage-backed security or collateralized mortgage obligation), and may also involve different or greater risks, including the risk that distributions from the underlying assets will be inadequate to make interest or other payments to the Fund, the risk that the issuer of the securities will fail to administer the underlying assets properly or become insolvent, and the risk that the securities will be less liquid than other Fund investments. |
| Retail [Member] | Thornburg Strategic Income Fund | Zero Coupon Bonds and Stripped Securities Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Zero Coupon Bonds and Stripped Securities Risk – Zero coupon bonds are corporate or government-issued debt obligations that do not provide for periodic or “coupon” payments of interest, and that are issued at a substantial discount to their face value. The buyer of a zero coupon bond realizes a stated rate of return determined by the gradual accretion in the value of the security. A “stripped” security is a debt obligation that has been transformed into a zero coupon bond by creating a separate, new security comprised of the separate income component of the debt obligation (commonly referred to as an “income only” or “I/O” security) or the separate principal component of the debt obligation (commonly referred to as a “principal only” or “P/O” security). Because zero coupon bonds do not provide for periodic payments of interest, their value is generally more volatile than the value of a comparable, interest-paying bond. The Fund may also have to recognize income on the bond and make distributions to shareholders before it has received any cash payments on the bond. To generate the cash necessary to satisfy such distributions, the Fund may have to sell portfolio securities that it otherwise might have continued to hold or use cash flows from other sources, including the proceeds from the sale of Fund shares. Additional information about Fund investments, investment strategies and risks of investing in the Fund appears beginning on page 125 of the Prospectus. |
| Retail [Member] | Thornburg Strategic Income Fund | Risk Lose Money [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Accordingly, the loss of money is a risk of investing in the Fund. |
| Retail [Member] | Thornburg Strategic Income Fund | Risk Not Insured [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | An investment in the Fund is not a deposit in any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. |
| Retail [Member] | Thornburg Short Duration Municipal Fund | Credit Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Credit Risk – If obligations held by the Fund are downgraded by ratings agencies or go into default, or if legislation or other government action reduces the ability of issuers to pay principal and interest when due, the value of those obligations may decline and the Fund’s share value and any dividends paid by the Fund may be reduced. For example, municipal leases held by the Fund may be subject to non-appropriation provisions which permit governmental agencies or issuers to discontinue payments to the Fund under the municipal leases. |
| Retail [Member] | Thornburg Short Duration Municipal Fund | Cybersecurity and Operational Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Cybersecurity and Operational Risk – Operational failures, cyber-attacks or other disruptions that affect the Fund’s service providers, the Fund’s counterparties, other market participants or the issuers of securities held by the Fund may adversely affect the Fund and its shareholders, including by causing losses for the Fund or impairing Fund operations. The rapid development and increasingly widespread use of artificial intelligence, including machine learning technology and generative artificial intelligence such as ChatGPT, could exacerbate these risks. |
| Retail [Member] | Thornburg Short Duration Municipal Fund | Liquidity Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Liquidity Risk – Due to a lack of demand in the marketplace or other factors, the Fund may not be able to sell promptly some or all of the obligations that it holds, or may only be able to sell obligations at less than desired prices. |
| Retail [Member] | Thornburg Short Duration Municipal Fund | Management Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Management Risk – The Fund is an actively managed portfolio, and the value of the Fund may be reduced if Thornburg pursues unsuccessful investments or fails to correctly identify risks affecting the broad economy or specific issuers in which the Fund invests. |
| Retail [Member] | Thornburg Short Duration Municipal Fund | Market and Economic Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Market and Economic Risk – The value of the Fund’s investments may decline and its share value may be reduced due to changes in general economic and market conditions. This effect is typically more pronounced for the Fund’s investments in lower rated and unrated municipal obligations, the value of which may fluctuate more significant in response to poor economic growth or other changes in market conditions, political, economic, legal, and technological developments, and developments affecting specific issuers. |
| Retail [Member] | Thornburg Short Duration Municipal Fund | Redemption Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Redemption Risk – If a significant percentage of the Fund’s shares is owned or controlled by a single shareholder, the Fund is subject to the risk that a redemption by that shareholder of all or a large portion of its shares may require the Fund to sell securities at less than desired prices, and the Fund’s remaining shareholders may also incur additional transaction costs or adverse tax consequences from such trading activity. |
| Retail [Member] | Thornburg Short Duration Municipal Fund | High Yield Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | High Yield Risk – Debt obligations that are rated below investment grade and unrated obligations of similar credit quality (commonly referred to as “junk” or “high yield” bonds) may have a substantial risk of loss. These obligations are generally considered to be speculative with respect to the issuer’s ability to pay interest and principal when due. These obligations may be subject to greater price volatility than investment grade obligations, and their prices may decline significantly in periods of general economic difficulty or in response to adverse publicity, changes in investor perceptions or other factors. These obligations may also be subject to greater liquidity risk. |
| Retail [Member] | Thornburg Short Duration Municipal Fund | Interest Rate Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Interest Rate Risk – When interest rates increase, the value of the Fund’s investments may decline and the Fund’s share value may be reduced. This effect is typically more pronounced for intermediate and longer-term obligations. When interest rates decrease, the Fund’s dividends may decline. Decreases in market interest rates may also result in prepayments of obligations the Fund acquires, requiring the Fund to reinvest at lower interest rates. |
| Retail [Member] | Thornburg Short Duration Municipal Fund | Tax Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Tax Risk – The income on the Fund’s municipal obligations could become subject to federal income or state income tax due to noncompliant conduct by issuers, unfavorable legislation or litigation or adverse interpretations by regulatory authorities. All or a portion of the Fund’s distributions that are exempt from regular federal income tax may nevertheless be taken into account for purposes of the federal AMT and state income tax. Additional information about Fund investments, investment strategies and risks of investing in the Fund appears beginning on page 125 of the Prospectus. |
| Retail [Member] | Thornburg Short Duration Municipal Fund | Risk Lose Money [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Accordingly, the loss of money is a risk of investing in the Fund. |
| Retail [Member] | Thornburg Short Duration Municipal Fund | Risk Not Insured [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | An investment in the Fund is not a deposit in any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. |
| Retail [Member] | Thornburg Limited Term Municipal Fund | Credit Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Credit Risk – If obligations held by the Fund are downgraded by ratings agencies or go into default, or if legislation or other government action reduces the ability of issuers to pay principal and interest when due, the value of those obligations may decline and the Fund’s share value and the dividends paid by the Fund may be reduced. Lower-rated or unrated obligations held by the Fund may have, or may be perceived to have, greater risk of default and ratings downgrades. For example, municipal leases held by the Fund may be subject to non-appropriation provisions which permit governmental agencies or issuers to discontinue payments to the Fund under the municipal leases. |
| Retail [Member] | Thornburg Limited Term Municipal Fund | Cybersecurity and Operational Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Cybersecurity and Operational Risk – Operational failures, cyber-attacks or other disruptions that affect the Fund’s service providers, the Fund’s counterparties, other market participants or the issuers of securities held by the Fund may adversely affect the Fund and its shareholders, including by causing losses for the Fund or impairing Fund operations. The rapid development and increasingly widespread use of artificial intelligence, including machine learning technology and generative artificial intelligence such as ChatGPT, could exacerbate these risks. |
| Retail [Member] | Thornburg Limited Term Municipal Fund | Liquidity Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Liquidity Risk – Due to a lack of demand in the marketplace or other factors, the Fund may not be able to sell promptly some or all of the obligations that it holds, or may only be able to sell obligations at less than desired prices. The market for lower- rated and unrated obligations may be less liquid than the market for other obligations, making it difficult for the Fund to value its investment in a lower-rated or unrated obligation or to sell the investment in a timely manner or at an acceptable price. |
| Retail [Member] | Thornburg Limited Term Municipal Fund | Management Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Management Risk – The Fund is an actively managed portfolio, and the value of the Fund may be reduced if Thornburg pursues unsuccessful investments or fails to correctly identify risks affecting the broad economy or specific issuers in which the Fund invests. |
| Retail [Member] | Thornburg Limited Term Municipal Fund | Market and Economic Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Market and Economic Risk – The value of the Fund’s investments may decline and its share value may be reduced due to changes in general economic and market conditions. This effect is typically more pronounced for the Fund’s investments in lower- rated and unrated municipal obligations, the value of which may fluctuate more significantly in response to poor economic growth or other changes in market conditions, political, economic, legal, and technological developments, and developments affecting specific issuers. |
| Retail [Member] | Thornburg Limited Term Municipal Fund | Redemption Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Redemption Risk – If a significant percentage of the Fund’s shares is owned or controlled by a single shareholder, the Fund is subject to the risk that a redemption by that shareholder of all or a large portion of its shares may require the Fund to sell securities at less than desired prices, and the Fund’s remaining shareholders may also incur additional transaction costs or adverse tax consequences from such trading activity. |
| Retail [Member] | Thornburg Limited Term Municipal Fund | High Yield Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | High Yield Risk – Debt obligations that are rated below investment grade and unrated obligations of similar credit quality (commonly referred to as “junk” or “high yield” bonds) may have a substantial risk of loss. These obligations are generally considered to be speculative with respect to the issuer’s ability to pay interest and principal when due. These obligations may be subject to greater price volatility than investment grade obligations, and their prices may decline significantly in periods of general economic difficulty or in response to adverse publicity, changes in investor perceptions or other factors. These obligations may also be subject to greater liquidity risk. |
| Retail [Member] | Thornburg Limited Term Municipal Fund | Interest Rate Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Interest Rate Risk – When interest rates increase, the value of the Fund’s investments may decline and the Fund’s share value may be reduced. This effect is typically more pronounced for intermediate and longer-term obligations. When interest rates decrease, the Fund’s dividends may decline. Decreases in market interest rates may also result in prepayments of obligations the Fund acquires, requiring the Fund to reinvest at lower interest rates. |
| Retail [Member] | Thornburg Limited Term Municipal Fund | Tax Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Tax Risk – The income on the Fund’s municipal obligations could become subject to federal income or state income tax due to noncompliant conduct by issuers, unfavorable legislation or litigation or adverse interpretations by regulatory authorities. All or a portion of the Fund’s distributions that are exempt from regular federal income tax may nevertheless be taken into account for purposes of the federal AMT and state income tax. Additional information about Fund investments, investment strategies and risks of investing in the Fund appears beginning on page 125 of the Prospectus. |
| Retail [Member] | Thornburg Limited Term Municipal Fund | Risk Lose Money [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Accordingly, the loss of money is a risk of investing in the Fund. |
| Retail [Member] | Thornburg Limited Term Municipal Fund | Risk Not Insured [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | An investment in the Fund is not a deposit in any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. |
| Retail [Member] | Thornburg Intermediate Municipal Fund | Credit Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Credit Risk – If obligations held by the Fund are downgraded by ratings agencies or go into default, or if legislation or other government action reduces the ability of issuers to pay principal and interest when due, the value of those obligations may decline and the Fund’s share value and the dividends paid by the Fund may be reduced. Lower-rated or unrated obligations held by the Fund may have, or may be perceived to have, greater risk of default and ratings downgrades. For example, municipal leases held by the Fund may be subject to non-appropriation provisions which permit governmental agencies or issuers to discontinue payments to the Fund under the municipal leases. |
| Retail [Member] | Thornburg Intermediate Municipal Fund | Cybersecurity and Operational Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Cybersecurity and Operational Risk – Operational failures, cyber-attacks or other disruptions that affect the Fund’s service providers, the Fund’s counterparties, other market participants or the issuers of securities held by the Fund may adversely affect the Fund and its shareholders, including by causing losses for the Fund or impairing Fund operations. The rapid development and increasingly widespread use of artificial intelligence, including machine learning technology and generative artificial intelligence such as ChatGPT, could exacerbate these risks. |
| Retail [Member] | Thornburg Intermediate Municipal Fund | Liquidity Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Liquidity Risk – Due to a lack of demand in the marketplace or other factors, the Fund may not be able to sell promptly some or all of the obligations that it holds, or may only be able to sell obligations at less than desired prices. The market for lower-rated and unrated obligations may be less liquid than the market for other obligations, making it difficult for the Fund to value its investment in a lower-rated or unrated obligation or to sell the investment in a timely manner or at an acceptable price. |
| Retail [Member] | Thornburg Intermediate Municipal Fund | Management Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Management Risk – The Fund is an actively managed portfolio, and the value of the Fund may be reduced if Thornburg pursues unsuccessful investments or fails to correctly identify risks affecting the broad economy or specific issuers in which the Fund invests. |
| Retail [Member] | Thornburg Intermediate Municipal Fund | Market and Economic Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Market and Economic Risk – The value of the Fund’s investments may decline and its share value may be reduced due to changes in general economic and market conditions. This effect is typically more pronounced for the Fund’s investments in lower- rated and unrated municipal obligations, the value of which may fluctuate more significantly in response to poor economic growth or other changes in market conditions, political, economic, legal, and technological developments, and developments affecting specific issuers. |
| Retail [Member] | Thornburg Intermediate Municipal Fund | Redemption Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Redemption Risk – If a significant percentage of the Fund’s shares is owned or controlled by a single shareholder, the Fund is subject to the risk that a redemption by that shareholder of all or a large portion of its shares may require the Fund to sell securities at less than desired prices, and the Fund’s remaining shareholders may also incur additional transaction costs or adverse tax consequences from such trading activity. |
| Retail [Member] | Thornburg Intermediate Municipal Fund | High Yield Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | High Yield Risk – Debt obligations that are rated below investment grade and unrated obligations of similar credit quality (commonly referred to as “junk” or “high yield” bonds) may have a substantial risk of loss. These obligations are generally considered to be speculative with respect to the issuer’s ability to pay interest and principal when due. These obligations may be subject to greater price volatility than investment grade obligations, and their prices may decline significantly in periods of general economic difficulty or in response to adverse publicity, changes in investor perceptions or other factors. These obligations may also be subject to greater liquidity risk. |
| Retail [Member] | Thornburg Intermediate Municipal Fund | Interest Rate Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Interest Rate Risk – When interest rates increase, the value of the Fund’s investments may decline and the Fund’s share value may be reduced. This effect is typically more pronounced for intermediate and longer-term obligations. When interest rates decrease, the Fund’s dividends may decline. Decreases in market interest rates may also result in prepayments of obligations the Fund acquires, requiring the Fund to reinvest at lower interest rates. |
| Retail [Member] | Thornburg Intermediate Municipal Fund | Tax Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Tax Risk – The income on the Fund’s municipal obligations could become subject to federal income or state income tax due to noncompliant conduct by issuers, unfavorable legislation or litigation or adverse interpretations by regulatory authorities. All or a portion of the Fund’s distributions that are exempt from regular federal income tax may nevertheless be taken into account for purposes of the federal AMT and state income tax. Additional information about Fund investments, investment strategies and risks of investing in the Fund appears beginning on page 125 of the Prospectus. |
| Retail [Member] | Thornburg Intermediate Municipal Fund | Risk Lose Money [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Accordingly, the loss of money is a risk of investing in the Fund. |
| Retail [Member] | Thornburg Intermediate Municipal Fund | Risk Not Insured [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | An investment in the Fund is not a deposit in any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. |
| Retail [Member] | Thornburg Strategic Municipal Income Fund | Credit Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Credit Risk – If obligations held by the Fund are downgraded by ratings agencies or go into default, or if legislation or other government action reduces the ability of issuers to pay principal and interest when due, the value of those obligations may decline and the Fund’s share value and the dividends paid by the Fund may be reduced. Because the ability of an issuer of a lower-rated or unrated obligation to pay principal and interest when due is typically less certain than for an issuer of a higher- rated obligation, lower-rated and unrated obligations are generally more vulnerable than higher-rated obligations to default, to ratings downgrades, and to liquidity risk. For example, municipal leases held by the Fund may be subject to non-appropriation provisions which permit governmental agencies or issuers to discontinue payments to the Fund under the municipal leases. |
| Retail [Member] | Thornburg Strategic Municipal Income Fund | Cybersecurity and Operational Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Cybersecurity and Operational Risk – Operational failures, cyber-attacks or other disruptions that affect the Fund’s service providers, the Fund’s counterparties, other market participants or the issuers of securities held by the Fund may adversely affect the Fund and its shareholders, including by causing losses for the Fund or impairing Fund operations. The rapid development and increasingly widespread use of artificial intelligence, including machine learning technology and generative artificial intelligence such as ChatGPT, could exacerbate these risks. |
| Retail [Member] | Thornburg Strategic Municipal Income Fund | Liquidity Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Liquidity Risk – Due to a lack of demand in the marketplace or other factors, the Fund may not be able to sell promptly some or all of the obligations that it holds, or may only be able to sell obligations at less than desired prices. The market for lower-rated and unrated obligations (including particularly “junk” or “high yield” bonds) may be less liquid than the market for other obligations, making it difficult for the Fund to value its investment in a lower-rated or unrated obligation or to sell the investment in a timely manner or at an acceptable price. |
| Retail [Member] | Thornburg Strategic Municipal Income Fund | Management Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Management Risk – The Fund is an actively managed portfolio, and the value of the Fund may be reduced if Thornburg pursues unsuccessful investments or fails to correctly identify risks affecting the broad economy or specific issuers in which the Fund invests. |
| Retail [Member] | Thornburg Strategic Municipal Income Fund | Market and Economic Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Market and Economic Risk – The value of the Fund’s investments may decline and its share value may be reduced due to changes in general economic and market conditions. This effect is typically more pronounced for the Fund’s investments in lower-rated and unrated municipal obligations (including particularly “junk” or “high yield” bonds), the value of which may fluctuate more significantly in response to poor economic growth or other changes in market conditions, political, economic, legal, and technological developments, and developments affecting specific issuers. |
| Retail [Member] | Thornburg Strategic Municipal Income Fund | Redemption Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Redemption Risk – If a significant percentage of the Fund’s shares is owned or controlled by a single shareholder, the Fund is subject to the risk that a redemption by that shareholder of all or a large portion of its shares may require the Fund to sell securities at less than desired prices, and the Fund’s remaining shareholders may also incur additional transaction costs or adverse tax consequences from such trading activity. |
| Retail [Member] | Thornburg Strategic Municipal Income Fund | High Yield Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | High Yield Risk – Debt obligations that are rated below investment grade and unrated obligations of similar credit quality (commonly referred to as “junk” or “high yield” bonds) may have a substantial risk of loss. These obligations are generally considered to be speculative with respect to the issuer’s ability to pay interest and principal when due. These obligations may be subject to greater price volatility than investment grade obligations, and their prices may decline significantly in periods of general economic difficulty or in response to adverse publicity, changes in investor perceptions or other factors. These obligations may also be subject to greater liquidity risk. |
| Retail [Member] | Thornburg Strategic Municipal Income Fund | Interest Rate Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Interest Rate Risk – When interest rates increase, the value of the Fund’s investments may decline and the Fund’s share value may be reduced. This effect is typically more pronounced for intermediate and longer-term obligations. When interest rates decrease, the Fund’s dividends may decline. Decreases in market interest rates may also result in prepayments of obligations the Fund acquires, requiring the Fund to reinvest at lower interest rates. |
| Retail [Member] | Thornburg Strategic Municipal Income Fund | Tax Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Tax Risk – The income on the Fund’s municipal obligations could become subject to federal income or state income tax due to noncompliant conduct by issuers, unfavorable legislation or litigation or adverse interpretations by regulatory authorities. All or a portion of the Fund’s distributions that are exempt from regular federal income tax may nevertheless be taken into account for purposes of the federal AMT and state income tax. Additional information about Fund investments, investment strategies and risks of investing in the Fund appears beginning on page 125 of the Prospectus. |
| Retail [Member] | Thornburg Strategic Municipal Income Fund | Risk Lose Money [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Accordingly, the loss of money is a risk of investing in the Fund. |
| Retail [Member] | Thornburg Strategic Municipal Income Fund | Risk Not Insured [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | An investment in the Fund is not a deposit in any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. |
| Retail [Member] | Thornburg California Limited Term Municipal Fund | Credit Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Credit Risk – If obligations held by the Fund are downgraded by ratings agencies or go into default, or if legislation or other government action reduces the ability of issuers to pay principal and interest when due, the value of those obligations may decline and the Fund’s share value and the dividends paid by the Fund may be reduced. Lower-rated or unrated obligations held by the Fund may have, or may be perceived to have, greater risk of default and ratings downgrades. For example, municipal leases held by the Fund may be subject to non-appropriation provisions which permit governmental agencies or issuers to discontinue payments to the Fund under the municipal leases. |
| Retail [Member] | Thornburg California Limited Term Municipal Fund | Cybersecurity and Operational Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Cybersecurity and Operational Risk – Operational failures, cyber-attacks or other disruptions that affect the Fund’s service providers, the Fund’s counterparties, other market participants or the issuers of securities held by the Fund may adversely affect the Fund and its shareholders, including by causing losses for the Fund or impairing Fund operations. The rapid development and increasingly widespread use of artificial intelligence, including machine learning technology and generative artificial intelligence such as ChatGPT, could exacerbate these risks. |
| Retail [Member] | Thornburg California Limited Term Municipal Fund | Liquidity Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Liquidity Risk – Due to a lack of demand in the marketplace or other factors, the Fund may not be able to sell promptly some or all of the obligations that it holds, or may only be able to sell obligations at less than desired prices. The market for lower- rated and unrated obligations may be less liquid than the market for other obligations, making it difficult for the Fund to value its investment in a lower-rated or unrated obligation or to sell the investment in a timely manner or at an acceptable price. |
| Retail [Member] | Thornburg California Limited Term Municipal Fund | Management Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Management Risk – The Fund is an actively managed portfolio, and the value of the Fund may be reduced if Thornburg pursues unsuccessful investments or fails to correctly identify risks affecting the broad economy or specific issuers in which the Fund invests. |
| Retail [Member] | Thornburg California Limited Term Municipal Fund | Market and Economic Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Market and Economic Risk – The value of the Fund’s investments may decline and its share value may be reduced due to changes in general economic and market conditions. This effect is typically more pronounced for the Fund’s investments in lower- rated and unrated municipal obligations, the value of which may fluctuate more significant in response to poor economic growth or other changes in market conditions, political, economic, legal, and technological developments, and developments affecting specific issuers. |
| Retail [Member] | Thornburg California Limited Term Municipal Fund | Redemption Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Redemption Risk – If a significant percentage of the Fund’s shares is owned or controlled by a single shareholder, the Fund is subject to the risk that a redemption by that shareholder of all or a large portion of its shares may require the Fund to sell securities at less than desired prices, and the Fund’s remaining shareholders may also incur additional transaction costs or adverse tax consequences from such trading activity. |
| Retail [Member] | Thornburg California Limited Term Municipal Fund | High Yield Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | High Yield Risk – Debt obligations that are rated below investment grade and unrated obligations of similar credit quality (commonly referred to as “junk” or “high yield” bonds) may have a substantial risk of loss. These obligations are generally considered to be speculative with respect to the issuer’s ability to pay interest and principal when due. These obligations may be subject to greater price volatility than investment grade obligations, and their prices may decline significantly in periods of general economic difficulty or in response to adverse publicity, changes in investor perceptions or other factors. These obligations may also be subject to greater liquidity risk. |
| Retail [Member] | Thornburg California Limited Term Municipal Fund | Interest Rate Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Interest Rate Risk – When interest rates increase, the value of the Fund’s investments may decline and the Fund’s share value may be reduced. This effect is typically more pronounced for intermediate and longer-term obligations. When interest rates decrease, the Fund’s dividends may decline. Decreases in market interest rates may also result in prepayments of obligations the Fund acquires, requiring the Fund to reinvest at lower interest rates. |
| Retail [Member] | Thornburg California Limited Term Municipal Fund | Tax Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Tax Risk – The income on the Fund’s municipal obligations could become subject to federal income or state income tax due to noncompliant conduct by issuers, unfavorable legislation or litigation or adverse interpretations by regulatory authorities. All or a portion of the Fund’s distributions that are exempt from regular federal income tax may nevertheless be taken into account for purposes of the federal AMT and state income tax. Additional information about Fund investments, investment strategies and risks of investing in the Fund appears beginning on page 125 of the Prospectus. |
| Retail [Member] | Thornburg California Limited Term Municipal Fund | Single State Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Single State Risk – Because the Fund invests primarily in obligations originating in California, the Fund’s share value may be more sensitive to adverse economic, political or regulatory developments in that state. Budgetary concerns, decreased revenues, and adverse conditions significant to a sector of the state, municipalities within the state, or local economies may negatively affect the ability of state and local issuers to make full and timely principal or interest payments on their debt obligations. |
| Retail [Member] | Thornburg California Limited Term Municipal Fund | Risk Lose Money [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Accordingly, the loss of money is a risk of investing in the Fund. |
| Retail [Member] | Thornburg California Limited Term Municipal Fund | Risk Not Insured [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | An investment in the Fund is not a deposit in any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. |
| Retail [Member] | Thornburg New Mexico Intermediate Municipal Fund | Credit Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Credit Risk – If obligations held by the Fund are downgraded by ratings agencies or go into default, or if legislation or other government action reduces the ability of issuers to pay principal and interest when due, the value of those obligations may decline and the Fund’s share value and the dividends paid by the Fund may be reduced. Lower-rated or unrated obligations held by the Fund may have, or may be perceived to have, greater risk of default and ratings downgrades. For example, municipal leases held by the Fund may be subject to non-appropriation provisions which permit governmental agencies or issuers to discontinue payments to the Fund under the municipal leases. |
| Retail [Member] | Thornburg New Mexico Intermediate Municipal Fund | Cybersecurity and Operational Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Cybersecurity and Operational Risk – Operational failures, cyber-attacks or other disruptions that affect the Fund’s service providers, the Fund’s counterparties, other market participants or the issuers of securities held by the Fund may adversely affect the Fund and its shareholders, including by causing losses for the Fund or impairing Fund operations. The rapid development and increasingly widespread use of artificial intelligence, including machine learning technology and generative artificial intelligence such as ChatGPT, could exacerbate these risks. |
| Retail [Member] | Thornburg New Mexico Intermediate Municipal Fund | Liquidity Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Liquidity Risk – Due to a lack of demand in the marketplace or other factors, the Fund may not be able to sell promptly some or all of the obligations that it holds, or may only be able to sell obligations at less than desired prices. The market for lower- rated and unrated obligations may be less liquid than the market for other obligations, making it difficult for the Fund to value its investment in a lower-rated or unrated obligation or to sell the investment in a timely manner or at an acceptable price. |
| Retail [Member] | Thornburg New Mexico Intermediate Municipal Fund | Management Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Management Risk – The Fund is an actively managed portfolio, and the value of the Fund may be reduced if Thornburg pursues unsuccessful investments or fails to correctly identify risks affecting the broad economy or specific issuers in which the Fund invests. |
| Retail [Member] | Thornburg New Mexico Intermediate Municipal Fund | Market and Economic Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Market and Economic Risk – The value of the Fund’s investments may decline and its share value may be reduced due to changes in general economic and market conditions. This effect is typically more pronounced for the Fund’s investments in lower- rated and unrated municipal obligations, the value of which may fluctuate more significant in response to poor economic growth or other changes in market conditions, political, economic, legal, and technological developments, and developments affecting specific issuers. |
| Retail [Member] | Thornburg New Mexico Intermediate Municipal Fund | Redemption Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Redemption Risk – If a significant percentage of the Fund’s shares is owned or controlled by a single shareholder, the Fund is subject to the risk that a redemption by that shareholder of all or a large portion of its shares may require the Fund to sell securities at less than desired prices, and the Fund’s remaining shareholders may also incur additional transaction costs or adverse tax consequences from such trading activity. |
| Retail [Member] | Thornburg New Mexico Intermediate Municipal Fund | High Yield Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | High Yield Risk – Debt obligations that are rated below investment grade and unrated obligations of similar credit quality (commonly referred to as “junk” or “high yield” bonds) may have a substantial risk of loss. These obligations are generally considered to be speculative with respect to the issuer’s ability to pay interest and principal when due. These obligations may be subject to greater price volatility than investment grade obligations, and their prices may decline significantly in periods of general economic difficulty or in response to adverse publicity, changes in investor perceptions or other factors. These obligations may also be subject to greater liquidity risk. |
| Retail [Member] | Thornburg New Mexico Intermediate Municipal Fund | Interest Rate Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Interest Rate Risk – When interest rates increase, the value of the Fund’s investments may decline and the Fund’s share value may be reduced. This effect is typically more pronounced for intermediate and longer-term obligations. When interest rates decrease, the Fund’s dividends may decline. Decreases in market interest rates may also result in prepayments of obligations the Fund acquires, requiring the Fund to reinvest at lower interest rates. |
| Retail [Member] | Thornburg New Mexico Intermediate Municipal Fund | Tax Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Tax Risk – The income on the Fund’s municipal obligations could become subject to federal income or state income tax due to noncompliant conduct by issuers, unfavorable legislation or litigation or adverse interpretations by regulatory authorities. All or a portion of the Fund’s distributions that are exempt from regular federal income tax may nevertheless be taken into account for purposes of the federal AMT and state income tax. Additional information about Fund investments, investment strategies and risks of investing in the Fund appears beginning on page 125 of the Prospectus. |
| Retail [Member] | Thornburg New Mexico Intermediate Municipal Fund | Single State Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Single State Risk – Because the Fund invests primarily in obligations originating in New Mexico, the Fund’s share value may be more sensitive to adverse economic, political or regulatory developments in that state. Budgetary concerns, decreased revenues, and adverse conditions significant to a sector of the state, municipalities within the state, or local economies may negatively affect the ability of state and local issuers to make full and timely principal or interest payments on their debt obligations. |
| Retail [Member] | Thornburg New Mexico Intermediate Municipal Fund | Risk Lose Money [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Accordingly, the loss of money is a risk of investing in the Fund. |
| Retail [Member] | Thornburg New Mexico Intermediate Municipal Fund | Risk Not Insured [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | An investment in the Fund is not a deposit in any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. |
| Retail [Member] | Thornburg New Mexico Intermediate Municipal Fund | Risk Nondiversified Status [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Non-diversification Risk – The Fund is a non-diversified investment company, which means that it may invest a greater proportion of its assets in the securities of a single issuer. This may be riskier, because a default or other adverse condition affecting such an issuer could cause the Fund’s share price to decline to a greater degree. |
| Retail [Member] | Thornburg New York Intermediate Municipal Fund | Credit Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Credit Risk – If obligations held by the Fund are downgraded by ratings agencies or go into default, or if legislation or other government action reduces the ability of issuers to pay principal and interest when due, the value of those obligations may decline and the Fund’s share value and the dividends paid by the Fund may be reduced. Lower-rated or unrated obligations held by the Fund may have, or may be perceived to have, greater risk of default and ratings downgrades. For example, municipal leases held by the Fund may be subject to non-appropriation provisions which permit governmental agencies or issuers to discontinue payments to the Fund under the municipal leases. |
| Retail [Member] | Thornburg New York Intermediate Municipal Fund | Cybersecurity and Operational Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Cybersecurity and Operational Risk – Operational failures, cyber-attacks or other disruptions that affect the Fund’s service providers, the Fund’s counterparties, other market participants or the issuers of securities held by the Fund may adversely affect the Fund and its shareholders, including by causing losses for the Fund or impairing Fund operations. The rapid development and increasingly widespread use of artificial intelligence, including machine learning technology and generative artificial intelligence such as ChatGPT, could exacerbate these risks. |
| Retail [Member] | Thornburg New York Intermediate Municipal Fund | Liquidity Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Liquidity Risk – Due to a lack of demand in the marketplace or other factors, the Fund may not be able to sell promptly some or all of the obligations that it holds, or may only be able to sell obligations at less than desired prices. The market for lower- rated and unrated obligations may be less liquid than the market for other obligations, making it difficult for the Fund to value its investment in a lower-rated or unrated obligation or to sell the investment in a timely manner or at an acceptable price. |
| Retail [Member] | Thornburg New York Intermediate Municipal Fund | Management Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Management Risk – The Fund is an actively managed portfolio, and the value of the Fund may be reduced if Thornburg pursues unsuccessful investments or fails to correctly identify risks affecting the broad economy or specific issuers in which the Fund invests. |
| Retail [Member] | Thornburg New York Intermediate Municipal Fund | Market and Economic Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Market and Economic Risk – The value of the Fund’s investments may decline and its share value may be reduced due to changes in general economic and market conditions. This effect is typically more pronounced for the Fund’s investments in lower- rated and unrated municipal obligations, the value of which may fluctuate more significantly in response to poor economic growth or other changes in market conditions, political, economic, legal, and technological developments, and developments affecting specific issuers. |
| Retail [Member] | Thornburg New York Intermediate Municipal Fund | Redemption Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Redemption Risk – If a significant percentage of the Fund’s shares is owned or controlled by a single shareholder, the Fund is subject to the risk that a redemption by that shareholder of all or a large portion of its shares may require the Fund to sell securities at less than desired prices, and the Fund’s remaining shareholders may also incur additional transaction costs or adverse tax consequences from such trading activity. |
| Retail [Member] | Thornburg New York Intermediate Municipal Fund | High Yield Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | High Yield Risk – Debt obligations that are rated below investment grade and unrated obligations of similar credit quality (commonly referred to as “junk” or “high yield” bonds) may have a substantial risk of loss. These obligations are generally considered to be speculative with respect to the issuer’s ability to pay interest and principal when due. These obligations may be subject to greater price volatility than investment grade obligations, and their prices may decline significantly in periods of general economic difficulty or in response to adverse publicity, changes in investor perceptions or other factors. These obligations may also be subject to greater liquidity risk. |
| Retail [Member] | Thornburg New York Intermediate Municipal Fund | Interest Rate Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Interest Rate Risk – When interest rates increase, the value of the Fund’s investments may decline and the Fund’s share value may be reduced. This effect is typically more pronounced for intermediate and longer-term obligations. When interest rates decrease, the Fund’s dividends may decline. Decreases in market interest rates may also result in prepayments of obligations the Fund acquires, requiring the Fund to reinvest at lower interest rates. |
| Retail [Member] | Thornburg New York Intermediate Municipal Fund | Tax Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Tax Risk – The income on the Fund’s municipal obligations could become subject to federal income or state income tax due to noncompliant conduct by issuers, unfavorable legislation or litigation or adverse interpretations by regulatory authorities. All or a portion of the Fund’s distributions that are exempt from regular federal income tax may nevertheless be taken into account for purposes of the federal AMT and state income tax. Additional information about Fund investments, investment strategies and risks of investing in the Fund appears beginning on page 125 of the Prospectus. |
| Retail [Member] | Thornburg New York Intermediate Municipal Fund | Single State Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Single State Risk – Because the Fund invests primarily in obligations originating in New York, the Fund’s share value may be more sensitive to adverse economic, political or regulatory developments in that state. Budgetary concerns, decreased revenues, and adverse conditions significant to a sector of the state, municipalities within the state, or local economies may negatively affect the ability of state and local issuers to make full and timely principal or interest payments on their debt obligations. |
| Retail [Member] | Thornburg New York Intermediate Municipal Fund | Risk Lose Money [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Accordingly, the loss of money is a risk of investing in the Fund. |
| Retail [Member] | Thornburg New York Intermediate Municipal Fund | Risk Not Insured [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | An investment in the Fund is not a deposit in any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. |
| Retail [Member] | Thornburg New York Intermediate Municipal Fund | Risk Nondiversified Status [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Non-diversification Risk – The Fund is a non-diversified investment company, which means that it may invest a greater proportion of its assets in the securities of a single issuer. This may be riskier, because a default or other adverse condition affecting such an issuer could cause the Fund’s share price to decline to a greater degree. |
| Retirement | Thornburg Global Opportunities Fund | Credit Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Credit Risk – The inability of an issuer to pay principal and interest on its debt obligations when due, or the downgrading of an issuer’s debt obligations by ratings agencies, may adversely affect the market’s perceptions of the issuer’s financial strength and may therefore result in declines in the issuer’s stock price. |
| Retirement | Thornburg Global Opportunities Fund | Cybersecurity and Operational Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Cybersecurity and Operational Risk – Operational failures, cyber-attacks or other disruptions that affect the Fund’s service providers, the Fund’s counterparties, other market participants or the issuers of securities held by the Fund may adversely affect the Fund and its shareholders, including by causing losses for the Fund or impairing Fund operations. The rapid development and increasingly widespread use of artificial intelligence, including machine learning technology and generative artificial intelligence such as ChatGPT, could exacerbate these risks. |
| Retirement | Thornburg Global Opportunities Fund | Developing Country Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Developing Country Risk – The risks which may affect investments in foreign issuers (see “Foreign Investment Risk,” below) may be more pronounced for investments in developing countries because the economies of those countries are usually less diversified, communications, transportation and economic infrastructures are less developed, and developing countries ordinarily have less established legal, political, business and social frameworks. At times the prices of equity securities of a developing country issuer may be extremely volatile. An issuer domiciled in a developed country may be similarly affected by these developing country risks to the extent that the issuer conducts its business in developing countries. |
| Retirement | Thornburg Global Opportunities Fund | Equity Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Equity Risk – The value of the Fund’s equity investments may fluctuate significantly over time in response to factors affecting individual issuers, particular industries, or the market as a whole. Additionally, common stock ranks below preferred stock and debt securities in claims for dividends and for assets of a company in a liquidation or bankruptcy. |
| Retirement | Thornburg Global Opportunities Fund | Foreign Currency Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Foreign Currency Risk – Fluctuations in currency exchange rates can adversely affect the value of the Fund’s foreign investments. Such fluctuations may occur for a number of reasons, including market and economic conditions, or a government’s decision to devalue its currency or impose currency controls. |
| Retirement | Thornburg Global Opportunities Fund | Foreign Investment Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Foreign Investment Risk – Investments in securities of foreign issuers may involve risks including adverse fluctuations in currency exchange rates, political instability, confiscations, taxes or restrictions on currency exchange, difficulty in selling foreign investments, and reduced legal protection. |
| Retirement | Thornburg Global Opportunities Fund | Liquidity Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Liquidity Risk – Due to a lack of demand in the marketplace or other factors, the Fund may not be able to sell some or all of its investments promptly, or may only be able to sell investments at less than desired prices. This risk may be more pronounced for the Fund’s investments in developing countries. |
| Retirement | Thornburg Global Opportunities Fund | Management Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Management Risk – The Fund is an actively managed portfolio, and the value of the Fund may be reduced if Thornburg pursues unsuccessful investments or fails to correctly identify risks affecting the broad economy or specific issuers in which the Fund invests. |
| Retirement | Thornburg Global Opportunities Fund | Market and Economic Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Market and Economic Risk – The value of the Fund’s investments may decline and its share value may be reduced due to changes in general economic and market conditions. The value of a security may change in response to developments affecting entire economies, markets or industries, including changes in interest rates, political, legal, and technological developments, and general market volatility. |
| Retirement | Thornburg Global Opportunities Fund | Real Estate Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Real Estate Risk – The Fund’s investments in publicly traded real estate investment trusts (“REITs”) are subject to risks affecting real estate investments generally (including market conditions, competition, property obsolescence, changes in interest rates and casualty to real estate), as well as risks specifically affecting REITs (the quality and skill of REIT management and the internal expenses of the REIT). |
| Retirement | Thornburg Global Opportunities Fund | Redemption Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Redemption Risk – If a significant percentage of the Fund’s shares is owned or controlled by a single shareholder, the Fund is subject to the risk that a redemption by that shareholder of all or a large portion of its shares may require the Fund to sell securities at less than desired prices, and the Fund’s remaining shareholders may also incur additional transaction costs or adverse tax consequences from such trading activity. |
| Retirement | Thornburg Global Opportunities Fund | Risks Affecting Specific Countries or Regions [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Risks Affecting Specific Countries or Regions – If a significant portion of the Fund’s assets is invested in issuers that are economically exposed to one country or region, the Fund’s share value may be more susceptible to the conditions and developments in that country or region, and potentially more volatile than the share value of a more geographically diversified fund. A specific country or region could also be adversely affected by conditions or developments arising in other countries. For example, the U.S. government could take actions to prohibit or restrict individuals or companies within the U.S. from purchasing or holding the shares of issuers in another country, which may limit the Fund’s ability to invest in that country or cause the Fund to have to sell investments in that country at less than desired prices. The nature and degree of the risks affecting a given country or region, and the extent of the Fund’s exposure to any such country or region, is expected to vary over time. |
| Retirement | Thornburg Global Opportunities Fund | Risks Affecting Specific Issuers [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Risks Affecting Specific Issuers – The value of a security may decline in response to developments affecting the specific issuer of the security, even if the overall industry or economy is unaffected. These developments may include a variety of factors, including but not limited to management issues or other corporate disruption, a decline in revenues or profitability, an increase in costs, or an adverse effect on the issuer’s competitive position. |
| Retirement | Thornburg Global Opportunities Fund | Small and Mid-Cap Company Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Small and Mid-Cap Company Risk – Investments in small-capitalization companies and mid-capitalization companies may involve additional risks, which may be relatively higher with smaller companies. These additional risks may result from limited product lines, more limited access to markets and financial resources, greater vulnerability to competition and changes in markets, lack of management depth, increased volatility in share price, and possible difficulties in valuing or selling these investments. Additional information about Fund investments, investment strategies and risks of investing in the Fund appears below beginning on page 51 of the Prospectus. |
| Retirement | Thornburg Global Opportunities Fund | Risk Lose Money [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Accordingly, the loss of money is a risk of investing in the Fund. |
| Retirement | Thornburg Global Opportunities Fund | Risk Not Insured [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | An investment in the Fund is not a deposit in any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. |
| Retirement | Thornburg International Equity Fund | Credit Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Credit Risk – The inability of an issuer to pay principal and interest on its debt obligations when due, or the downgrading of an issuer’s debt obligations by ratings agencies, may adversely affect the market’s perceptions of the issuer’s financial strength and may therefore result in declines in the issuer’s stock price. |
| Retirement | Thornburg International Equity Fund | Cybersecurity and Operational Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Cybersecurity and Operational Risk – Operational failures, cyber-attacks or other disruptions that affect the Fund’s service providers, the Fund’s counterparties, other market participants or the issuers of securities held by the Fund may adversely affect the Fund and its shareholders, including by causing losses for the Fund or impairing Fund operations. The rapid development and increasingly widespread use of artificial intelligence, including machine learning technology and generative artificial intelligence such as ChatGPT, could exacerbate these risks. |
| Retirement | Thornburg International Equity Fund | Developing Country Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Developing Country Risk – The risks which may affect investments in foreign issuers (see “Foreign Investment Risk,” below) may be more pronounced for investments in developing countries because the economies of those countries are usually less diversified, communications, transportation and economic infrastructures are less developed, and developing countries ordinarily have less established legal, political, business and social frameworks. At times the prices of equity securities of a developing country issuer may be extremely volatile. An issuer domiciled in a developed country may be similarly affected by these developing country risks to the extent that the issuer conducts its business in developing countries. |
| Retirement | Thornburg International Equity Fund | Equity Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Equity Risk – The value of the Fund’s equity investments may fluctuate significantly over time in response to factors affecting individual issuers, particular industries, or the market as a whole. Additionally, common stock ranks below preferred stock and debt securities in claims for dividends and for assets of a company in a liquidation or bankruptcy. |
| Retirement | Thornburg International Equity Fund | Foreign Currency Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Foreign Currency Risk – Fluctuations in currency exchange rates can adversely affect the value of the Fund’s foreign investments. Such fluctuations may occur for a number of reasons, including market and economic conditions, or a government’s decision to devalue its currency or impose currency controls. |
| Retirement | Thornburg International Equity Fund | Foreign Investment Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Foreign Investment Risk – Investments in securities of foreign issuers may involve risks including adverse fluctuations in currency exchange rates, political instability, confiscations, taxes or restrictions on currency exchange, difficulty in selling foreign investments, and reduced legal protection. |
| Retirement | Thornburg International Equity Fund | Liquidity Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Liquidity Risk – Due to a lack of demand in the marketplace or other factors, the Fund may not be able to sell some or all of its investments promptly, or may only be able to sell investments at less than desired prices. |
| Retirement | Thornburg International Equity Fund | Management Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Management Risk – The Fund is an actively managed portfolio, and the value of the Fund may be reduced if Thornburg pursues unsuccessful investments or fails to correctly identify risks affecting the broad economy or specific issuers in which the Fund invests. |
| Retirement | Thornburg International Equity Fund | Market and Economic Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Market and Economic Risk – The value of the Fund’s investments may decline and its share value may be reduced due to changes in general economic and market conditions. The value of a security may change in response to developments affecting entire economies, markets or industries, including changes in interest rates, political, legal, and technological developments, and general market volatility. |
| Retirement | Thornburg International Equity Fund | Redemption Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Redemption Risk – If a significant percentage of the Fund’s shares is owned or controlled by a single shareholder, the Fund is subject to the risk that a redemption by that shareholder of all or a large portion of its shares may require the Fund to sell securities at less than desired prices, and the Fund’s remaining shareholders may also incur additional transaction costs or adverse tax consequences from such trading activity. |
| Retirement | Thornburg International Equity Fund | Risks Affecting Specific Countries or Regions [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Risks Affecting Specific Countries or Regions – If a significant portion of the Fund’s assets is invested in issuers that are economically exposed to one country or region, the Fund’s share value may be more susceptible to the conditions and developments in that country or region, and potentially more volatile than the share value of a more geographically diversified fund. A specific country or region could also be adversely affected by conditions or developments arising in other countries. For example, the U.S. government could take actions to prohibit or restrict individuals or companies within the U.S. from purchasing or holding the shares of issuers in another country, which may limit the Fund’s ability to invest in that country or cause the Fund to have to sell investments in that country at less than desired prices. The nature and degree of the risks affecting a given country or region, and the extent of the Fund’s exposure to any such country or region, is expected to vary over time. |
| Retirement | Thornburg International Equity Fund | Risks Affecting Specific Issuers [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Risks Affecting Specific Issuers – The value of a security may decline in response to developments affecting the specific issuer of the security, even if the overall industry or economy is unaffected. These developments may include a variety of factors, including but not limited to management issues or other corporate disruption, a decline in revenues or profitability, an increase in costs, or an adverse effect on the issuer’s competitive position. |
| Retirement | Thornburg International Equity Fund | Small and Mid-Cap Company Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Small and Mid-Cap Company Risk – Investments in small-capitalization companies and mid-capitalization companies may involve additional risks, which may be relatively higher with smaller companies. These additional risks may result from limited product lines, more limited access to markets and financial resources, greater vulnerability to competition and changes in markets, lack of management depth, increased volatility in share price, and possible difficulties in valuing or selling these investments. Additional information about Fund investments, investment strategies, and risks of investing in the Fund appears beginning on page 51 of the Prospectus. |
| Retirement | Thornburg International Equity Fund | Depositary Receipts Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Depositary Receipts Risk – An investment in American Depositary Receipts (“ADRs”), European Depositary Receipts (“EDRs”) or Global Depositary Receipts (“GDRs”) is an alternative to the purchase of the underlying securities in their national markets and/or currencies. However, ADRs, EDRs, and GDRs remain subject to many of the risks associated with investing directly in foreign securities, including the political and economic risks associated with the underlying issuer’s country. Certain countries may limit the ability to convert a depositary receipt into the underlying foreign security and vice versa, which may cause the securities of the foreign company to trade at a discount or premium to the market price of the related depositary receipts. Moreover, EDRs and GDRs can involve currency risk since, unlike ADRs, they may not be U.S. dollar denominated. |
| Retirement | Thornburg International Equity Fund | Risk Lose Money [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Accordingly, the loss of money is a risk of investing in the Fund. |
| Retirement | Thornburg International Equity Fund | Risk Not Insured [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | An investment in the Fund is not a deposit in any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. |
| Retirement | Thornburg International Growth Fund | Credit Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Credit Risk – The inability of an issuer to pay principal and interest on its debt obligations when due, or the downgrading of an issuer’s debt obligations by ratings agencies, may adversely affect the market’s perceptions of the issuer’s financial strength and may therefore result in declines in the issuer’s stock price. |
| Retirement | Thornburg International Growth Fund | Cybersecurity and Operational Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Cybersecurity and Operational Risk – Operational failures, cyber-attacks or other disruptions that affect the Fund’s service providers, the Fund’s counterparties, other market participants or the issuers of securities held by the Fund may adversely affect the Fund and its shareholders, including by causing losses for the Fund or impairing Fund operations. The rapid development and increasingly widespread use of artificial intelligence, including machine learning technology and generative artificial intelligence such as ChatGPT, could exacerbate these risks. |
| Retirement | Thornburg International Growth Fund | Developing Country Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Developing Country Risk – The risks which may affect investments in foreign issuers (see “Foreign Investment Risk,” below) may be more pronounced for investments in developing countries because the economies of those countries are usually less diversified, communications, transportation and economic infrastructures are less developed, and developing countries ordinarily have less established legal, political, business and social frameworks. At times the prices of equity securities of a developing country issuer may be extremely volatile. An issuer domiciled in a developed country may be similarly affected by these developing country risks to the extent that the issuer conducts its business in developing countries. |
| Retirement | Thornburg International Growth Fund | Equity Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Equity Risk – The value of the Fund’s equity investments may fluctuate significantly over time in response to factors affecting individual issuers, particular industries, or the market as a whole. Additionally, common stock ranks below preferred stock and debt securities in claims for dividends and for assets of a company in a liquidation or bankruptcy. |
| Retirement | Thornburg International Growth Fund | Foreign Currency Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Foreign Currency Risk – Fluctuations in currency exchange rates can adversely affect the value of the Fund’s foreign investments. Such fluctuations may occur for a number of reasons, including market and economic conditions, or a government’s decision to devalue its currency or impose currency controls. |
| Retirement | Thornburg International Growth Fund | Foreign Investment Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Foreign Investment Risk – Investments in securities of foreign issuers may involve risks including adverse fluctuations in currency exchange rates, political instability, confiscations, taxes or restrictions on currency exchange, difficulty in selling foreign investments, and reduced legal protection. |
| Retirement | Thornburg International Growth Fund | Liquidity Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Liquidity Risk – Due to a lack of demand in the marketplace or other factors, the Fund may not be able to sell some or all of its investments promptly, or may only be able to sell investments at less than desired prices. This risk may be more pronounced for the Fund’s investments in developing countries. |
| Retirement | Thornburg International Growth Fund | Management Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Management Risk – The Fund is an actively managed portfolio, and the value of the Fund may be reduced if Thornburg pursues unsuccessful investments or fails to correctly identify risks affecting the broad economy or specific issuers in which the Fund invests. |
| Retirement | Thornburg International Growth Fund | Market and Economic Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Market and Economic Risk – The value of the Fund’s investments may decline and its share value may be reduced due to changes in general economic and market conditions. The value of a security may change in response to developments affecting entire economies, markets or industries, including changes in interest rates, political, legal, and technological developments, and general market volatility. |
| Retirement | Thornburg International Growth Fund | Redemption Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Redemption Risk – If a significant percentage of the Fund’s shares is owned or controlled by a single shareholder, the Fund is subject to the risk that a redemption by that shareholder of all or a large portion of its shares may require the Fund to sell securities at less than desired prices, and the Fund’s remaining shareholders may also incur additional transaction costs or adverse tax consequences from such trading activity. |
| Retirement | Thornburg International Growth Fund | Risks Affecting Specific Countries or Regions [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Risks Affecting Specific Countries or Regions – If a significant portion of the Fund’s assets is invested in issuers that are economically exposed to one country or region, the Fund’s share value may be more susceptible to the conditions and developments in that country or region, and potentially more volatile than the share value of a more geographically diversified fund. A specific country or region could also be adversely affected by conditions or developments arising in other countries. For example, the U.S. government could take actions to prohibit or restrict individuals or companies within the U.S. from purchasing or holding the shares of issuers in another country, which may limit the Fund’s ability to invest in that country or cause the Fund to have to sell investments in that country at less than desired prices. The nature and degree of the risks affecting a given country or region, and the extent of the Fund’s exposure to any such country or region, is expected to vary over time. |
| Retirement | Thornburg International Growth Fund | Risks Affecting Specific Issuers [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Risks Affecting Specific Issuers – The value of a security may decline in response to developments affecting the specific issuer of the security, even if the overall industry or economy is unaffected. These developments may include a variety of factors, including but not limited to management issues or other corporate disruption, a decline in revenues or profitability, an increase in costs, or an adverse effect on the issuer’s competitive position. |
| Retirement | Thornburg International Growth Fund | Small and Mid-Cap Company Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Small and Mid-Cap Company Risk – Investments in small-capitalization companies and mid-capitalization companies, including smaller, earlier stage companies, may involve additional risks. These risks may be relatively higher with smaller companies. These additional risks may result from limited product lines, more limited access to markets and financial resources, greater vulnerability to competition and changes in markets, lack of management depth, increased volatility in share price, and possible difficulties in valuing or selling these investments. Additional information about Fund investments, investment strategies, and risks of investing in the Fund appears beginning on page 51 of the Prospectus. |
| Retirement | Thornburg International Growth Fund | Depositary Receipts Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Depositary Receipts Risk – An investment in American Depositary Receipts (“ADRs”), European Depositary Receipts (“EDRs”) or Global Depositary Receipts (“GDRs”) is an alternative to the purchase of the underlying securities in their national markets and/or currencies. However, ADRs, EDRs, and GDRs remain subject to many of the risks associated with investing directly in foreign securities, including the political and economic risks associated with the underlying issuer’s country. Certain countries may limit the ability to convert a depositary receipt into the underlying foreign security and vice versa, which may cause the securities of the foreign company to trade at a discount or premium to the market price of the related depositary receipts. Moreover, EDRs and GDRs can involve currency risk since, unlike ADRs, they may not be U.S. dollar denominated. |
| Retirement | Thornburg International Growth Fund | Growth Company Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Growth Company Risk – Growth company stocks may trade at higher multiples of current earnings than other equity securities and, therefore, may be more sensitive to changes in current or expected earnings than other equity securities and may be more volatile. If growth companies do not increase their earnings at a rate expected by investors, the market price of the stock may decline significantly, even if earnings show an absolute increase. Growth company stocks also typically lack the dividend yield that can cushion stock prices in market downturns. These risks may be more pronounced in companies that are in the earlier stages of their growth cycle. |
| Retirement | Thornburg International Growth Fund | Information Technology Securities Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Information Technology Securities Risk – Information technology companies may at times be more vulnerable to product obsolescence caused by rapid technology changes, the failure to obtain or maintain intellectual property rights, the inability to develop new products, competition from new and existing market entrants, and changes in consumer preferences. Information technology stocks may also be more volatile than the overall market. |
| Retirement | Thornburg International Growth Fund | Risk Lose Money [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Accordingly, the loss of money is a risk of investing in the Fund. |
| Retirement | Thornburg International Growth Fund | Risk Not Insured [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | An investment in the Fund is not a deposit in any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. |
| Retirement | Thornburg Developing World Fund | Credit Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Credit Risk – The inability of an issuer to pay principal and interest on its debt obligations when due, or the downgrading of an issuer’s debt obligations by ratings agencies, may adversely affect the market’s perceptions of the issuer’s financial strength and may therefore result in declines in the issuer’s stock price. |
| Retirement | Thornburg Developing World Fund | Cybersecurity and Operational Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Cybersecurity and Operational Risk – Operational failures, cyber-attacks or other disruptions that affect the Fund’s service providers, the Fund’s counterparties, other market participants or the issuers of securities held by the Fund may adversely affect the Fund and its shareholders, including by causing losses for the Fund or impairing Fund operations. The rapid development and increasingly widespread use of artificial intelligence, including machine learning technology and generative artificial intelligence such as ChatGPT, could exacerbate these risks. |
| Retirement | Thornburg Developing World Fund | Developing Country Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Developing Country Risk – The risks which may affect investments in foreign issuers (see “Foreign Investment Risk,” below) may be more pronounced for investments in developing countries because the economies of those countries are usually less diversified, communications, transportation and economic infrastructures are less developed, and developing countries ordinarily have less established legal, political, business and social frameworks. At times the prices of equity securities of a developing country issuer may be extremely volatile. An issuer domiciled in a developed country may be similarly affected by these developing country risks to the extent that the issuer conducts its business in developing countries. |
| Retirement | Thornburg Developing World Fund | Equity Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Equity Risk – The value of the Fund’s equity investments may fluctuate significantly over time in response to factors affecting individual issuers, particular industries, or the market as a whole. Additionally, common stock ranks below preferred stock and debt securities in claims for dividends and for assets of a company in a liquidation or bankruptcy. |
| Retirement | Thornburg Developing World Fund | Foreign Currency Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Foreign Currency Risk – Fluctuations in currency exchange rates can adversely affect the value of the Fund’s foreign investments. Such fluctuations may occur for a number of reasons, including market and economic conditions, or a government’s decision to devalue its currency or impose currency controls. |
| Retirement | Thornburg Developing World Fund | Foreign Investment Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Foreign Investment Risk – Investments in securities of foreign issuers may involve risks including adverse fluctuations in currency exchange rates, political instability, confiscations, taxes or restrictions on currency exchange, difficulty in selling foreign investments, and reduced legal protections. |
| Retirement | Thornburg Developing World Fund | Liquidity Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Liquidity Risk – Due to a lack of demand in the marketplace or other factors, the Fund may not be able to sell some or all of its investments promptly, or may only be able to sell investments at less than desired prices. This risk may be more pronounced for the Fund’s investments in developing countries. |
| Retirement | Thornburg Developing World Fund | Management Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Management Risk – The Fund is an actively managed portfolio, and the value of the Fund may be reduced if Thornburg pursues unsuccessful investments or fails to correctly identify risks affecting the broad economy or specific issuers in which the Fund invests. |
| Retirement | Thornburg Developing World Fund | Market and Economic Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Market and Economic Risk – The value of the Fund’s investments may decline and its share value may be reduced due to changes in general economic and market conditions. The value of a security may change in response to developments affecting entire economies, markets or industries, including changes in interest rates, political, legal, and technological developments, and general market volatility. These risks may be more pronounced for the Fund’s investments in developing countries. |
| Retirement | Thornburg Developing World Fund | Redemption Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Redemption Risk – If a significant percentage of the Fund’s shares is owned or controlled by a single shareholder, the Fund is subject to the risk that a redemption by that shareholder of all or a large portion of its shares may require the Fund to sell securities at less than desired prices, and the Fund’s remaining shareholders may also incur additional transaction costs or adverse tax consequences from such trading activity. |
| Retirement | Thornburg Developing World Fund | Risks Affecting Specific Countries or Regions [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Risks Affecting Specific Countries or Regions – If a significant portion of the Fund’s assets is invested in issuers that are economically exposed to one country or region, the Fund’s share value may be more susceptible to the conditions and developments in that country or region, and potentially more volatile than the share value of a more geographically diversified fund. A specific country or region could also be adversely affected by conditions or developments arising in other countries. For example, the U.S. government could take actions to prohibit or restrict individuals or companies within the U.S. from purchasing or holding the shares of issuers in another country, which may limit the Fund’s ability to invest in that country or cause the Fund to have to sell investments in that country at less than desired prices. The nature and degree of the risks affecting a given country or region, and the extent of the Fund’s exposure to any such country or region, is expected to vary over time. |
| Retirement | Thornburg Developing World Fund | Risks Affecting Specific Issuers [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Risks Affecting Specific Issuers – The value of an equity security may decline in response to developments affecting the specific issuer of the security or obligation, even if the overall industry or economy is unaffected. These developments may include a variety of factors, including but not limited to management issues or other corporate disruption, a decline in revenues or profitability, an increase in costs, or an adverse effect on the issuer’s competitive position. |
| Retirement | Thornburg Developing World Fund | Small and Mid-Cap Company Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Small and Mid-Cap Company Risk – Investments in small-capitalization companies and mid-capitalization companies may involve additional risks, which may be relatively higher with smaller companies. These additional risks may result from limited product lines, more limited access to markets and financial resources, greater vulnerability to competition and changes in markets, lack of management depth, increased volatility in share price, and possible difficulties in valuing or selling these investments. Additional information about Fund investments, investment strategies and risks of investing in the Fund appears below beginning on page 51 of the Prospectus. |
| Retirement | Thornburg Developing World Fund | Risk Lose Money [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Accordingly, the loss of money is a risk of investing in the Fund. |
| Retirement | Thornburg Developing World Fund | Risk Not Insured [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | An investment in the Fund is not a deposit in any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. |
| Retirement | Thornburg Investment Income Builder Fund | Credit Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Credit Risk – If debt obligations held by the Fund are downgraded by ratings agencies or go into default, or if management action, legislation or other government action reduces the ability of issuers to pay principal and interest when due, the value of those obligations may decline and the Fund’s share value and the dividends paid by the Fund may be reduced. Because the ability of an issuer of a lower-rated or unrated obligation to pay principal and interest when due is typically less certain than for an issuer of a higher-rated obligation, lower-rated and unrated obligations are generally more vulnerable than higher-rated obligations to default, to ratings downgrades, and to liquidity risk. The inability of an issuer to pay principal and interest on its debt obligations when due, or the downgrading of an issuer’s debt obligations by ratings agencies, may adversely affect the market’s perceptions of the issuer’s financial strength and may therefore result in declines in the issuer’s stock price. |
| Retirement | Thornburg Investment Income Builder Fund | Cybersecurity and Operational Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Cybersecurity and Operational Risk – Operational failures, cyber-attacks or other disruptions that affect the Fund’s service providers, the Fund’s counterparties, other market participants or the issuers of securities held by the Fund may adversely affect the Fund and its shareholders, including by causing losses for the Fund or impairing Fund operations. The rapid development and increasingly widespread use of artificial intelligence, including machine learning technology and generative artificial intelligence such as ChatGPT, could exacerbate these risks. |
| Retirement | Thornburg Investment Income Builder Fund | Developing Country Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Developing Country Risk – The risks which may affect investments in foreign issuers (see “Foreign Investment Risk,” below) may be more pronounced for investments in developing countries because the economies of those countries are usually less diversified, communications, transportation and economic infrastructures are less developed, and developing countries ordinarily have less established legal, political, business and social frameworks. At times the prices of equity securities or debt obligations of a developing country issuer may be extremely volatile. An issuer domiciled in a developed country may be similarly affected by these developing country risks to the extent that the issuer conducts its business in developing countries. |
| Retirement | Thornburg Investment Income Builder Fund | Equity Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Equity Risk – The value of the Fund’s equity investments may fluctuate significantly over time in response to factors affecting individual issuers, particular industries, or the market as a whole. Additionally, common stock ranks below preferred stock and debt securities in claims for dividends and for assets of a company in a liquidation or bankruptcy. |
| Retirement | Thornburg Investment Income Builder Fund | Foreign Currency Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Foreign Currency Risk – Fluctuations in currency exchange rates can adversely affect the value of the Fund’s foreign investments. Such fluctuations may occur for a number of reasons, including market and economic conditions, or a government’s decision to devalue its currency or impose currency controls. |
| Retirement | Thornburg Investment Income Builder Fund | Foreign Investment Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Foreign Investment Risk – Investments in securities of foreign issuers may involve risks including adverse fluctuations in currency exchange rates, political instability, confiscations, taxes or restrictions on currency exchange, difficulty in selling foreign investments, and reduced legal protection. In addition, some foreign government debt obligations may be subject to default, delays in payment, adverse legislation or government action, or could be downgraded by ratings agencies. |
| Retirement | Thornburg Investment Income Builder Fund | Liquidity Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Liquidity Risk – Due to a lack of demand in the marketplace or other factors, the Fund may not be able to sell some or all of its investments promptly, or may only be able to sell investments at less than desired prices. |
| Retirement | Thornburg Investment Income Builder Fund | Management Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Management Risk – The Fund is an actively managed portfolio, and the value of the Fund may be reduced if Thornburg pursues unsuccessful investments or fails to correctly identify risks affecting the broad economy or specific issuers in which the Fund invests. |
| Retirement | Thornburg Investment Income Builder Fund | Market and Economic Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Market and Economic Risk – The value of the Fund’s investments may decline and its share value may be reduced due to changes in general economic and market conditions. The value of a security may change in response to developments affecting entire economies, markets or industries, including changes in interest rates, political, legal, and technological developments, and general market volatility. |
| Retirement | Thornburg Investment Income Builder Fund | Real Estate Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Real Estate Risk – The Fund’s investments in publicly traded real estate investment trusts (“REITs”) are subject to risks affecting real estate investments generally (including market conditions, competition, property obsolescence, changes in interest rates and casualty to real estate), as well as risks specifically affecting REITs (the quality and skill of REIT management and the internal expenses of the REIT). |
| Retirement | Thornburg Investment Income Builder Fund | Redemption Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Redemption Risk – If a significant percentage of the Fund’s shares is owned or controlled by a single shareholder, the Fund is subject to the risk that a redemption by that shareholder of all or a large portion of its shares may require the Fund to sell securities at less than desired prices, and the Fund’s remaining shareholders may also incur additional transaction costs or adverse tax consequences from such trading activity. |
| Retirement | Thornburg Investment Income Builder Fund | Risks Affecting Specific Countries or Regions [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Risks Affecting Specific Countries or Regions – If a significant portion of the Fund’s assets is invested in issuers that are economically exposed to one country or region, the Fund’s share value may be more susceptible to the conditions and developments in that country or region, and potentially more volatile than the share value of a more geographically diversified fund. A specific country or region could also be adversely affected by conditions or developments arising in other countries. For example, the U.S. government could take actions to prohibit or restrict individuals or companies within the U.S. from purchasing or holding the shares of issuers in another country, which may limit the Fund’s ability to invest in that country or cause the Fund to have to sell investments in that country at less than desired prices. The nature and degree of the risks affecting a given country or region, and the extent of the Fund’s exposure to any such country or region, is expected to vary over time. |
| Retirement | Thornburg Investment Income Builder Fund | Risks Affecting Specific Issuers [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Risks Affecting Specific Issuers – The value of an equity security or debt obligation may decline in response to developments affecting the specific issuer of the security or obligation, even if the overall industry or economy is unaffected. These developments may include a variety of factors, including but not limited to management issues or other corporate disruption, a decline in revenues or profitability, an increase in costs, or an adverse effect on the issuer’s competitive position. |
| Retirement | Thornburg Investment Income Builder Fund | Small and Mid-Cap Company Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Small and Mid-Cap Company Risk – Investments in small-capitalization companies and mid-capitalization companies may involve additional risks, which may be relatively higher with smaller companies. These additional risks may result from limited product lines, more limited access to markets and financial resources, greater vulnerability to competition and changes in markets, lack of management depth, increased volatility in share price, and possible difficulty in valuing or selling these investments. |
| Retirement | Thornburg Investment Income Builder Fund | Convertible Debt Obligation Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Convertible Debt Obligation Risk – The market value of a convertible debt obligation may vary with changes in prevailing interest rates and changing evaluations of the ability of the issuer to meet principal and interest payments. The market value of a convertible debt obligation may also vary in accordance with the market value of the underlying stock. As a result, convertible debt obligations held by the Fund will tend to perform more like equity securities when the underlying stock price is high (because it is assumed that the Fund will convert the obligation), and more like non-convertible debt obligations when the underlying stock price is low (because it is assumed that the Fund will not convert the obligation). Because its market value can be influenced by several factors, a convertible debt obligation will not be as sensitive to interest rate changes as a similar non-convertible debt obligation, and generally will have less potential for gain or loss than the underlying stock. |
| Retirement | Thornburg Investment Income Builder Fund | Foreign Government Obligations Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Foreign Government Obligations Risk – Debt obligations may be issued by foreign governments and their agencies and instrumentalities, including the governments of developing countries and “supra-national” entities such as the International Bank for Reconstruction and Development. The Fund’s investments in these foreign debt obligations may be denominated in U.S. dollars or in foreign currencies. These securities, even if denominated in U.S. dollars, may be affected significantly by fluctuations in the value of foreign currencies, and the value of these securities in U.S. dollars may decline even if the securities increase in value in their home country. The governmental issuers of these debt obligations may be less willing or able than the U.S. to repay principal and interest when due, and they may require that the terms for payment be renegotiated. In some countries there may be political instability or insufficient government supervision of markets, and the legal protections for the Fund’s investments could be subject to unfavorable judicial or administrative changes. These risks may be more pronounced for the Fund’s investments in debt obligations issued by developing countries. |
| Retirement | Thornburg Investment Income Builder Fund | High Yield Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | High Yield Risk – Debt obligations that are rated below investment grade and unrated obligations of similar credit quality (commonly referred to as “junk” or “high yield” bonds) may have a substantial risk of loss. These obligations are generally considered to be speculative with respect to the issuer’s ability to pay interest and principal when due. These obligations may be subject to greater price volatility than investment grade obligations, and their prices may decline significantly in periods of general economic difficulty or in response to adverse publicity, changes in investor perceptions or other factors. These obligations may also be subject to greater liquidity risk. |
| Retirement | Thornburg Investment Income Builder Fund | Interest Rate Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Interest Rate Risk – When interest rates increase, the value of the Fund’s investments in debt obligations may decline and the Fund’s share value may be reduced. This effect is typically more pronounced for intermediate and longer-term obligations. This effect is also typically more pronounced for mortgage- and other asset-backed securities, the value of which may fluctuate more significantly in response to interest rate changes. When interest rates decrease, the Fund’s dividends may decline. |
| Retirement | Thornburg Investment Income Builder Fund | Prepayment and Extension Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Prepayment and Extension Risk – When market interest rates decline, certain debt obligations held by the Fund may be repaid more quickly than anticipated, requiring the Fund to reinvest the proceeds of those repayments in obligations which bear a lower interest rate. Conversely, when market interest rates increase, certain debt obligations held by the Fund may be repaid more slowly than anticipated, causing assets of the Fund to remain invested in relatively lower yielding obligations. These risks may be more pronounced for the Fund’s investments in mortgage-backed and asset-backed securities. |
| Retirement | Thornburg Investment Income Builder Fund | U.S. Government Obligations Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | U.S. Government Obligations Risk – U.S. government obligations are subject to the same risks affecting other debt obligations. Although securities backed by the full faith credit of the U.S. government are commonly regarded as having relatively less risk of default, it is possible that the U.S. government may be unwilling or unable to repay principal and interest when due and may require that the terms for payment be renegotiated. Further obligations that are backed by the full faith and credit of the U.S. government remain subject to the other general risks applicable to debt obligations, such as market risks, liquidity risks, and interest rate risks, and may be subject to ratings downgrades. U.S. government obligations also include obligations of U.S. government agencies, instrumentalities, and government-sponsored enterprises, commonly referred to as “agency obligations.” Some agency obligations are backed by the full faith and credit of the U.S. government, but other agency obligations have no specific backing or only limited support from the agency’s authority to borrow from the U.S. government or the discretionary authority of the Treasury to purchase obligations of the issuing agency. Additional information about Fund investments, investment strategies and risks of investing in the Fund appears below beginning on page 51 of the Prospectus. |
| Retirement | Thornburg Investment Income Builder Fund | Risk Lose Money [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Accordingly, the loss of money is a risk of investing in the Fund. |
| Retirement | Thornburg Investment Income Builder Fund | Risk Not Insured [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | An investment in the Fund is not a deposit in any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. |
| Retirement | Thornburg Limited Term U.S. Government Fund | Credit Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Credit Risk – All securities owned by the Fund may be subject to default, delays in payment, adverse legislation or other government action, or could be downgraded by ratings agencies, reducing the value of the Fund’s shares. Securities backed by the full faith and credit of the U.S. government, such as U.S. Treasury obligations, are commonly regarded as having small exposure to credit risk. Obligations of certain U.S. government agencies, instrumentalities and government-sponsored enterprises (sometimes referred to as “agency obligations”) are not direct obligations of the United States, may not be backed by the full faith and credit of the U.S. government, and may have a greater exposure to credit risk. Although the U.S. government is required by law to provide credit support for some agency obligations, there is no assurance that the U.S. government would provide financial support for any such obligation on a default by the issuing agency, instrumentality or enterprise in the absence of a legal requirement to do so. As of the date of this Prospectus, securities backed by the full faith and credit of the U.S. government, and securities of U.S. government agencies, instrumentalities and enterprises which may be purchased by the Fund are rated “Aaa” by Moody’s Investors Services or “AA+” by S&P Global Ratings. Ratings agencies may reduce the ratings of any securities in the future. |
| Retirement | Thornburg Limited Term U.S. Government Fund | Cybersecurity and Operational Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Cybersecurity and Operational Risk – Operational failures, cyber-attacks or other disruptions that affect the Fund’s service providers, the Fund’s counterparties, other market participants or the issuers of securities held by the Fund may adversely affect the Fund and its shareholders, including by causing losses for the Fund or impairing Fund operations. The rapid development and increasingly widespread use of artificial intelligence, including machine learning technology and generative artificial intelligence such as ChatGPT, could exacerbate these risks. |
| Retirement | Thornburg Limited Term U.S. Government Fund | Liquidity Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Liquidity Risk – Due to a lack of demand in the marketplace or other factors, the Fund may not be able to sell promptly some or all of the obligations that it holds, or may only be able to sell obligations at less than desired prices. |
| Retirement | Thornburg Limited Term U.S. Government Fund | Management Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Management Risk – The Fund is an actively managed portfolio, and the value of the Fund may be reduced if Thornburg pursues unsuccessful investments or fails to correctly identify risks affecting the broad economy or specific issuers in which the Fund invests. |
| Retirement | Thornburg Limited Term U.S. Government Fund | Market and Economic Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Market and Economic Risk – The value of the Fund’s investments may decline and its share value may be reduced due to changes in general economic and market conditions. For example, a fall in worldwide demand for U.S. government securities or general economic decline could lower the value of those securities. |
| Retirement | Thornburg Limited Term U.S. Government Fund | Redemption Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Redemption Risk – If a significant percentage of the Fund’s shares is owned or controlled by a single shareholder, the Fund is subject to the risk that a redemption by that shareholder of all or a large portion of its shares may require the Fund to sell securities at less than desired prices, and the Fund’s remaining shareholders may also incur additional transaction costs or adverse tax consequences from such trading activity. |
| Retirement | Thornburg Limited Term U.S. Government Fund | Interest Rate Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Interest Rate Risk – When interest rates increase, the value of the Fund’s investments may decline and the Fund’s share value may be reduced. This effect is typically more pronounced for intermediate and longer-term obligations. This effect is also typically more pronounced for the Fund’s investment in mortgage-backed securities, the value of which may fluctuate more significantly in response to interest rate changes. When interest rates decrease, the Fund’s dividends may decline. |
| Retirement | Thornburg Limited Term U.S. Government Fund | Prepayment and Extension Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Prepayment and Extension Risk – When market interest rates decline, certain debt obligations held by the Fund may be repaid more quickly than anticipated, requiring the Fund to reinvest the proceeds of those repayments in obligations which bear a lower interest rate. Conversely, when market interest rates increase, certain debt obligations held by the Fund may be repaid more slowly than anticipated, causing assets of the Fund to remain invested in relatively lower yielding obligations. These risks may be more pronounced for the Fund’s investments in mortgage-backed securities. |
| Retirement | Thornburg Limited Term U.S. Government Fund | U.S. Government Obligations Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | U.S. Government Obligations Risk – U.S. government obligations are subject to the same risks affecting other debt obligations. Although securities backed by the full faith credit of the U.S. government are commonly regarded as having relatively less risk of default, it is possible that the U.S. government may be unwilling or unable to repay principal and interest when due and may require that the terms for payment be renegotiated. Further obligations that are backed by the full faith and credit of the U.S. government remain subject to the other general risks applicable to debt obligations, such as market risks, liquidity risks, and interest rate risks, and may be subject to ratings downgrades. U.S. government obligations also include obligations of U.S. government agencies, instrumentalities, and government-sponsored enterprises, commonly referred to as “agency obligations.” Some agency obligations are backed by the full faith and credit of the U.S. government, but other agency obligations have no specific backing or only limited support from the agency’s authority to borrow from the U.S. government or the discretionary authority of the Treasury to purchase obligations of the issuing agency. Additional information about Fund investments, investment strategies, and risks of investing in the Fund appears beginning on page 51 of the Prospectus. |
| Retirement | Thornburg Limited Term U.S. Government Fund | Structured Products Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Structured Products Risk – Investments in securities that are backed by, or represent interests in, an underlying pool of securities or other assets, including investments in mortgage-backed securities and in CMOs, involve the risks associated with the underlying assets (e.g., the risk of default by mortgagors whose mortgages are included in a mortgage-backed security or CMO), and may also involve different or greater risks, including the risk that distributions from the underlying assets will be inadequate to make interest or other payments to the Fund, the risk that the issuer of the securities will fail to administer the underlying assets properly or become insolvent, and the risk that the securities will be less liquid than other Fund investments. |
| Retirement | Thornburg Limited Term U.S. Government Fund | Risk Lose Money [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Accordingly, the loss of money is a risk of investing in the Fund. |
| Retirement | Thornburg Limited Term U.S. Government Fund | Risk Not Insured [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | An investment in the Fund is not a deposit in any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. |
| Retirement | Thornburg Limited Term Income Fund | Credit Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Credit Risk – All securities owned by the Fund may be subject to default, delays in payment, adverse legislation or other government action, or could be downgraded by ratings agencies, reducing the value of the Fund’s shares. Securities backed by the full faith and credit of the U.S. government, such as U.S. Treasury obligations, are commonly regarded as having small exposure to credit risk. Obligations of certain U.S. government agencies, instrumentalities and government sponsored enterprises (sometimes referred to as “agency obligations”) are not direct obligations of the United States, may not be backed by the full faith and credit of the U.S. government, and may have a greater exposure to credit risk. Although the U.S. government is required by law to provide credit support for some agency obligations, there is no assurance that the U.S. government would provide financial support for any such obligation on a default by the issuing agency, instrumentality or enterprise in the absence of a legal requirement to do so. As of the date of this Prospectus, securities backed by the full faith and credit of the U.S. government, and securities of U.S. government agencies, instrumentalities and enterprises which may be purchased by the Fund, are rated “Aaa” by Moody’s Investors Services or “AA+” by S&P Global Ratings. Ratings agencies may reduce the ratings of any securities in the future. Lower-rated or unrated obligations in which the Fund is permitted to invest may have, or may be perceived to have, greater risk of default and ratings downgrades. |
| Retirement | Thornburg Limited Term Income Fund | Cybersecurity and Operational Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Cybersecurity and Operational Risk – Operational failures, cyber-attacks or other disruptions that affect the Fund’s service providers, the Fund’s counterparties, other market participants or the issuers of securities held by the Fund may adversely affect the Fund and its shareholders, including by causing losses for the Fund or impairing Fund operations. The rapid development and increasingly widespread use of artificial intelligence, including machine learning technology and generative artificial intelligence such as ChatGPT, could exacerbate these risks. |
| Retirement | Thornburg Limited Term Income Fund | Foreign Investment Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Foreign Investment Risk – Investments in the debt obligations of foreign issuers may involve risks including adverse fluctuations in currency exchange rates, political instability, confiscations, taxes or restrictions on currency exchange, difficulty in selling foreign investments, and reduced legal protection. These risks may be more pronounced for investments in developing countries. In addition, some foreign government debt obligations may be subject to default, delays in payment, adverse legislation or government action, or could be downgraded by ratings agencies. |
| Retirement | Thornburg Limited Term Income Fund | Liquidity Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Liquidity Risk – Due to a lack of demand in the marketplace or other factors, the Fund may not be able to sell promptly some or all of the obligations that it holds, or may only be able to sell obligations at less than desired prices. |
| Retirement | Thornburg Limited Term Income Fund | Management Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Management Risk – The Fund is an actively managed portfolio, and the value of the Fund may be reduced if Thornburg pursues unsuccessful investments or fails to correctly identify risks affecting the broad economy or specific issuers in which the Fund invests. |
| Retirement | Thornburg Limited Term Income Fund | Market and Economic Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Market and Economic Risk – The value of the Fund’s investments may decline and its share value may be reduced due to changes in general economic and market conditions. For example, a fall in worldwide demand for U.S. government securities or general economic decline could lower the value of those securities. |
| Retirement | Thornburg Limited Term Income Fund | Redemption Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Redemption Risk – If a significant percentage of the Fund’s shares is owned or controlled by a single shareholder, the Fund is subject to the risk that a redemption by that shareholder of all or a large portion of its shares may require the Fund to sell securities at less than desired prices, and the Fund’s remaining shareholders may also incur additional transaction costs or adverse tax consequences from such trading activity. |
| Retirement | Thornburg Limited Term Income Fund | Risks Affecting Specific Issuers [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Risks Affecting Specific Issuers – The value of a debt obligation may decline in response to developments affecting the specific issuer of the obligation, even if other issuers or the overall economy are unaffected. These developments may include a variety of factors, including but not limited to management issues or other corporate disruption, a decline in revenues or profitability, an increase in costs, or an adverse effect on the issuer’s competitive position. |
| Retirement | Thornburg Limited Term Income Fund | Foreign Government Obligations Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Foreign Government Obligations Risk – Debt obligations may be issued by foreign governments and their agencies and instrumentalities, including the governments of developing countries and “supra-national” entities such as the International Bank for Reconstruction and Development. The Fund’s investments in these foreign debt obligations may be denominated in U.S. dollars or in foreign currencies. These securities, even if denominated in U.S. dollars, may be affected significantly by fluctuations in the value of foreign currencies, and the value of these securities in U.S. dollars may decline even if the securities increase in value in their home country. The governmental issuers of these debt obligations may be less willing or able than the U.S. to repay principal and interest when due, and they may require that the terms for payment be renegotiated. In some countries there may be political instability or insufficient government supervision of markets, and the legal protections for the Fund’s investments could be subject to unfavorable judicial or administrative changes. These risks may be more pronounced for the Fund’s investments in debt obligations issued by developing countries. |
| Retirement | Thornburg Limited Term Income Fund | Interest Rate Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Interest Rate Risk – When interest rates increase, the value of the Fund’s investments may decline and the Fund’s share value may be reduced. This effect is typically more pronounced for intermediate and longer-term obligations. This effect is also typically more pronounced for the Fund’s investment in mortgage- and other asset-backed securities, the value of which may fluctuate more significant in response to interest rate changes. When interest rates decrease, the Fund’s dividends may decline. |
| Retirement | Thornburg Limited Term Income Fund | Prepayment and Extension Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Prepayment and Extension Risk – When market interest rates decline, certain debt obligations held by the Fund may be repaid more quickly than anticipated, requiring the Fund to reinvest the proceeds of those repayments in obligations which bear a lower interest rate. Conversely, when market interest rates increase, certain debt obligations held by the Fund may be repaid more slowly than anticipated, causing assets of the Fund to remain invested in relatively lower yielding obligations. These risks may be more pronounced for the Fund’s investments in mortgage-backed and asset-backed securities. |
| Retirement | Thornburg Limited Term Income Fund | U.S. Government Obligations Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | U.S. Government Obligations Risk – U.S. government obligations are subject to the same risks affecting other debt obligations. Although securities backed by the full faith credit of the U.S. government are commonly regarded as having relatively less risk of default, it is possible that the U.S. government may be unwilling or unable to repay principal and interest when due and may require that the terms for payment be renegotiated. Further obligations that are backed by the full faith and credit of the U.S. government remain subject to the other general risks applicable to debt obligations, such as market risks, liquidity risks, and interest rate risks, and may be subject to ratings downgrades. U.S. government obligations also include obligations of U.S. government agencies, instrumentalities, and government-sponsored enterprises, commonly referred to as “agency obligations.” Some agency obligations are backed by the full faith and credit of the U.S. government, but other agency obligations have no specific backing or only limited support from the agency’s authority to borrow from the U.S. government or the discretionary authority of the Treasury to purchase obligations of the issuing agency. Additional information about Fund investments, investment strategies, and risks of investing in the Fund appears beginning on page 51 of the Prospectus. |
| Retirement | Thornburg Limited Term Income Fund | Structured Products Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Structured Products Risk – Investments in securities that are backed by, or represent interests in, an underlying pool of securities or other assets, including investments in mortgage- and asset-backed securities and in collateralized mortgage obligations and collateralized debt obligations, involve the risks associated with the underlying assets (e.g., the risk of default by mortgagors whose mortgages are included in a mortgage-backed security or collateralized mortgage obligation), and may also involve different or greater risks, including the risk that distributions from the underlying assets will be inadequate to make interest or other payments to the Fund, the risk that the issuer of the securities will fail to administer the underlying assets properly or become insolvent, and the risk that the securities will be less liquid than other Fund investments. |
| Retirement | Thornburg Limited Term Income Fund | Risk Lose Money [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Accordingly, the loss of money is a risk of investing in the Fund. |
| Retirement | Thornburg Limited Term Income Fund | Risk Not Insured [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | An investment in the Fund is not a deposit in any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. |
| Retirement | Thornburg Strategic Income Fund | Credit Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Credit Risk – If obligations held by the Fund are downgraded by ratings agencies or go into default, or if management action, legislation or other government action reduces the ability of issuers to pay principal and interest when due, the value of those obligations may decline and the Fund’s share value and the dividends paid by the Fund may be reduced. Because the ability of an issuer of a lower-rated or unrated obligation to pay principal and interest when due is typically less certain than for an issuer of a higher-rated obligation, lower-rated and unrated obligations are generally more vulnerable than higher- rated obligations to default, to ratings downgrades, and to liquidity risk. Debt obligations backed by so-called “subprime” mortgages may also be subject to a greater risk of default or downgrade. Debt obligations issued by the U.S. government or its agencies, instrumentalities and government sponsored enterprises are also subject to credit risk. Securities backed by the full faith and credit of the U.S. government, such as U.S. Treasury obligations, are commonly regarded as having small exposure to credit risk. Obligations of certain U.S. agencies, instrumentalities and enterprises (sometimes referred to as “agency obligations”) are not direct obligations of the U.S. government, may not be backed by the full faith and credit of the U.S. government, and may have a greater exposure to credit risk. |
| Retirement | Thornburg Strategic Income Fund | Cybersecurity and Operational Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Cybersecurity and Operational Risk – Operational failures, cyber-attacks or other disruptions that affect the Fund’s service providers, the Fund’s counterparties, other market participants or the issuers of securities held by the Fund may adversely affect the Fund and its shareholders, including by causing losses for the Fund or impairing Fund operations. The rapid development and increasingly widespread use of artificial intelligence, including machine learning technology and generative artificial intelligence such as ChatGPT, could exacerbate these risks. |
| Retirement | Thornburg Strategic Income Fund | Developing Country Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Developing Country Risk – The risks which may affect investments in foreign issuers (see “Foreign Investment Risk,” below) may be more pronounced for investments in developing countries because the economies of those countries are usually less diversified, communications, transportation and economic infrastructures are less developed, and developing countries ordinarily have less established legal, political, business and social frameworks. At times the prices of debt obligations of a developing country issuer may be extremely volatile. An issuer domiciled in a developed country may be similarly affected by these developing country risks to the extent that the issuer conducts its business in developing countries. |
| Retirement | Thornburg Strategic Income Fund | Foreign Currency Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Foreign Currency Risk – Fluctuations in currency exchange rates can adversely affect the value of the Fund’s foreign investments. Such fluctuations may occur for a number of reasons, including market and economic conditions, or a government’s decision to devalue its currency or impose currency controls. |
| Retirement | Thornburg Strategic Income Fund | Foreign Investment Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Foreign Investment Risk – Investments in the debt obligations of foreign issuers may involve risks including adverse fluctuations in currency exchange rates, political instability, confiscations, taxes or restrictions on currency exchange, difficulty in selling foreign investments, and reduced legal protection. In addition, some foreign government debt obligations may be subject to default, delays in payment, adverse legislation or government action, or could be downgraded by ratings agencies. |
| Retirement | Thornburg Strategic Income Fund | Liquidity Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Liquidity Risk – Due to a lack of demand in the marketplace or other factors, the Fund may not be able to sell some or all of its investments promptly, or may only be able to sell investments at less than desired prices. The market for lower-rated and unrated debt obligations (including particularly “junk” or “high yield” bonds) and debt obligations backed by so-called “subprime” mortgages may be less liquid than the market for other obligations, making it difficult for the Fund to value its investment in a lower-rated or unrated obligation or to sell the investment in a timely manner or at an acceptable price. |
| Retirement | Thornburg Strategic Income Fund | Management Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Management Risk – The Fund is an actively managed portfolio, and the value of the Fund may be reduced if Thornburg pursues unsuccessful investments or fails to correctly identify risks affecting the broad economy or specific issuers in which the Fund invests. |
| Retirement | Thornburg Strategic Income Fund | Market and Economic Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Market and Economic Risk – The value of the Fund’s investments may decline and its share value may be reduced due to changes in general economic and market conditions. This effect is typically more pronounced for lower-rated and unrated debt obligations (including particularly “junk” or “high yield” bonds), the value of which may fluctuate more significantly in response to poor economic growth or other changes in market conditions, political, economic, legal, and technological developments, and developments affecting specific issuers. The market value of any zero coupon bonds or “stripped” securities that the Fund may purchase will typically be more volatile than the value of a comparable, interest-paying bond. Additionally, zero coupon bonds and “stripped” securities are subject to the risk that the Fund may have to recognize income on its investment and make distributions to shareholders before it has received any cash payments on its investment. |
| Retirement | Thornburg Strategic Income Fund | Redemption Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Redemption Risk – If a significant percentage of the Fund’s shares is owned or controlled by a single shareholder, the Fund is subject to the risk that a redemption by that shareholder of all or a large portion of its shares may require the Fund to sell securities at less than desired prices, and the Fund’s remaining shareholders may also incur additional transaction costs or adverse tax consequences from such trading activity. |
| Retirement | Thornburg Strategic Income Fund | Risks Affecting Specific Issuers [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Risks Affecting Specific Issuers – The value of a debt obligation may decline in response to developments affecting the specific issuer of the obligation or security, even if the overall industry or economy is unaffected. These developments may include a variety of factors, including but not limited to management issues or other corporate disruption, a decline in revenues or profitability, an increase in costs, or an adverse effect on the issuer’s competitive position. |
| Retirement | Thornburg Strategic Income Fund | Small and Mid-Cap Company Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Small and Mid-Cap Company Risk – Investments in small-capitalization companies and mid-capitalization companies may involve additional risks, which may be relatively higher with smaller companies. These additional risks may result from limited product lines, more limited access to markets and financial resources, greater vulnerability to competition and changes in markets, lack of management depth, increased volatility in share price, and possible difficulties in valuing or selling these investments. |
| Retirement | Thornburg Strategic Income Fund | Convertible Debt Obligation Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Convertible Debt Obligation Risk – The market value of a convertible debt obligation may vary with changes in prevailing interest rates and changing evaluations of the ability of the issuer to meet principal and interest payments. The market value of a convertible debt obligation may also vary in accordance with the market value of the underlying stock. As a result, convertible debt obligations held by the Fund will tend to perform more like equity securities when the underlying stock price is high (because it is assumed that the Fund will convert the obligation), and more like non-convertible debt obligations when the underlying stock price is low (because it is assumed that the Fund will not convert the obligation). Because its market value can be influenced by several factors, a convertible debt obligation will not be as sensitive to interest rate changes as a similar non-convertible debt obligation, and generally will have less potential for gain or loss than the underlying stock. |
| Retirement | Thornburg Strategic Income Fund | Foreign Government Obligations Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Foreign Government Obligations Risk – Debt obligations may be issued by foreign governments and their agencies and instrumentalities, including the governments of developing countries and “supra-national” entities such as the International Bank for Reconstruction and Development. The Fund’s investments in these foreign debt obligations may be denominated in U.S. dollars or in foreign currencies. These securities, even if denominated in U.S. dollars, may be affected significantly by fluctuations in the value of foreign currencies, and the value of these securities in U.S. dollars may decline even if the securities increase in value in their home country. The governmental issuers of these debt obligations may be less willing or able than the U.S. to repay principal and interest when due, and they may require that the terms for payment be renegotiated. In some countries there may be political instability or insufficient government supervision of markets, and the legal protections for the Fund’s investments could be subject to unfavorable judicial or administrative changes. These risks may be more pronounced for the Fund’s investments in debt obligations issued by developing countries. |
| Retirement | Thornburg Strategic Income Fund | High Yield Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | High Yield Risk – Debt obligations that are rated below investment grade and unrated obligations of similar credit quality (commonly referred to as “junk” or “high yield” bonds) may have a substantial risk of loss. These obligations are generally considered to be speculative with respect to the issuer’s ability to pay interest and principal when due. These obligations may be subject to greater price volatility than investment grade obligations, and their prices may decline significantly in periods of general economic difficulty or in response to adverse publicity, changes in investor perceptions or other factors. These obligations may also be subject to greater liquidity risk. |
| Retirement | Thornburg Strategic Income Fund | Interest Rate Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Interest Rate Risk – When interest rates increase, the value of the Fund’s investments may decline and the Fund’s share value may be reduced. This effect is typically more pronounced for intermediate and longer-term obligations. This effect is also typically more pronounced for mortgage- and other asset-backed securities, the value of which may fluctuate more significantly in response to interest rate changes. When interest rates decrease, the Fund’s dividends may decline. |
| Retirement | Thornburg Strategic Income Fund | Prepayment and Extension Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Prepayment and Extension Risk – When market interest rates decline, certain debt obligations held by the Fund may be repaid more quickly than anticipated, requiring the Fund to reinvest the proceeds of those repayments in obligations which bear a lower interest rate. Conversely, when market interest rates increase, certain debt obligations held by the Fund may be repaid more slowly than anticipated, causing assets of the Fund to remain invested in relatively lower yielding obligations. These risks may be more pronounced for the Fund’s investments in mortgage-backed and asset-backed securities. |
| Retirement | Thornburg Strategic Income Fund | U.S. Government Obligations Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | U.S. Government Obligations Risk – U.S. government obligations are subject to the same risks affecting other debt obligations. Although securities backed by the full faith credit of the U.S. government are commonly regarded as having relatively less risk of default, it is possible that the U.S. government may be unwilling or unable to repay principal and interest when due and may require that the terms for payment be renegotiated. Further obligations that are backed by the full faith and credit of the U.S. government remain subject to the other general risks applicable to debt obligations, such as market risks, liquidity risks, and interest rate risks, and may be subject to ratings downgrades. U.S. government obligations also include obligations of U.S. government agencies, instrumentalities, and government-sponsored enterprises, commonly referred to as “agency obligations.” Some agency obligations are backed by the full faith and credit of the U.S. government, but other agency obligations have no specific backing or only limited support from the agency’s authority to borrow from the U.S. government or the discretionary authority of the Treasury to purchase obligations of the issuing agency. |
| Retirement | Thornburg Strategic Income Fund | Structured Products Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Structured Products Risk – Investments in securities that are backed by, or represent interests in, an underlying pool of securities or other assets, including investments in mortgage- and asset-backed securities and in collateralized mortgage obligations and collateralized debt obligations, involve the risks associated with the underlying assets (e.g., the risk of default by mortgagors whose mortgages are included in a mortgage-backed security or collateralized mortgage obligation), and may also involve different or greater risks, including the risk that distributions from the underlying assets will be inadequate to make interest or other payments to the Fund, the risk that the issuer of the securities will fail to administer the underlying assets properly or become insolvent, and the risk that the securities will be less liquid than other Fund investments. |
| Retirement | Thornburg Strategic Income Fund | Zero Coupon Bonds and Stripped Securities Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Zero Coupon Bonds and Stripped Securities Risk – Zero coupon bonds are corporate or government-issued debt obligations that do not provide for periodic or “coupon” payments of interest, and that are issued at a substantial discount to their face value. The buyer of a zero coupon bond realizes a stated rate of return determined by the gradual accretion in the value of the security. A “stripped” security is a debt obligation that has been transformed into a zero coupon bond by creating a separate, new security comprised of the separate income component of the debt obligation (commonly referred to as an “income only” or “I/O” security) or the separate principal component of the debt obligation (commonly referred to as a “principal only” or “P/O” security). Because zero coupon bonds do not provide for periodic payments of interest, their value is generally more volatile than the value of a comparable, interest-paying bond. The Fund may also have to recognize income on the bond and make distributions to shareholders before it has received any cash payments on the bond. To generate the cash necessary to satisfy such distributions, the Fund may have to sell portfolio securities that it otherwise might have continued to hold or use cash flows from other sources, including the proceeds from the sale of Fund shares. Additional information about Fund investments, investment strategies and risks of investing in the Fund appears below beginning on page 51 of the Prospectus. |
| Retirement | Thornburg Strategic Income Fund | Risk Lose Money [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Accordingly, the loss of money is a risk of investing in the Fund. |
| Retirement | Thornburg Strategic Income Fund | Risk Not Insured [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | An investment in the Fund is not a deposit in any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. |
| Managed Funds | Thornburg Emerging Markets Managed Account Fund | Credit Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Credit Risk – The inability of an issuer to pay principal and interest on its debt obligations when due, or the downgrading of an issuer’s debt obligations by ratings agencies, may adversely affect the market’s perceptions of the issuer’s financial strength and may therefore result in declines in the issuer’s stock price. |
| Managed Funds | Thornburg Emerging Markets Managed Account Fund | Cybersecurity and Operational Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Cybersecurity and Operational Risk – Operational failures, cyber-attacks or other disruptions that affect the Fund’s service providers, the Fund’s counterparties, other market participants or the issuers of securities held by the Fund may adversely affect the Fund and its shareholders, including by causing losses for the Fund or impairing Fund operations. The rapid development and increasingly widespread use of artificial intelligence, including machine learning technology and generative artificial intelligence such as ChatGPT, could exacerbate these risks. |
| Managed Funds | Thornburg Emerging Markets Managed Account Fund | Equity Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Equity Risk – The value of the Fund’s equity investments may fluctuate significantly over time in response to factors affecting individual issuers, particular industries, or the market as a whole. Additionally, common stock ranks below preferred stock and debt securities in claims for dividends and for assets of a company in a liquidation or bankruptcy. |
| Managed Funds | Thornburg Emerging Markets Managed Account Fund | Foreign Currency Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Foreign Currency Risk – Fluctuations in currency exchange rates can adversely affect the value of the Fund’s foreign investments. Such fluctuations may occur for a number of reasons, including market and economic conditions, or a government’s decision to devalue its currency or impose currency controls. |
| Managed Funds | Thornburg Emerging Markets Managed Account Fund | Foreign Investment Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Foreign Investment Risk – Investments in securities of foreign issuers may involve risks including adverse fluctuations in currency exchange rates, political instability, confiscations, taxes or restrictions on currency exchange, difficulty in selling foreign investments, and reduced legal protections. |
| Managed Funds | Thornburg Emerging Markets Managed Account Fund | Liquidity Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Liquidity Risk – Due to a lack of demand in the marketplace or other factors, the Fund may not be able to sell some or all of its investments promptly, or may only be able to sell investments at less than desired prices. This risk may be more pronounced for the Fund’s investments in emerging markets. |
| Managed Funds | Thornburg Emerging Markets Managed Account Fund | Management Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Management Risk – The Fund is an actively managed portfolio, and the value of the Fund may be reduced if Thornburg pursues unsuccessful investments or fails to correctly identify risks affecting the broad economy or specific issuers in which the Fund invests. |
| Managed Funds | Thornburg Emerging Markets Managed Account Fund | Market and Economic Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Market and Economic Risk – The value of the Fund’s investments may decline and its share value may be reduced due to changes in general economic and market conditions. The value of a security may change in response to developments affecting entire economies, markets or industries, including changes in interest rates, political, legal, and technological developments, and general market volatility. These risks may be more pronounced for the Fund’s investments in emerging markets. |
| Managed Funds | Thornburg Emerging Markets Managed Account Fund | Redemption Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Redemption Risk – Fund shares may only be redeemed by Thornburg on behalf of separately managed accounts or by certain managed account program sponsors and not by individual investors. If a significant percentage of the Fund’s shares is owned or controlled by a single managed account shareholder, the Fund is subject to the risk that a redemption by that managed account shareholder of all or a large portion of its shares may require the Fund to sell securities at less than desired prices, and the Fund’s remaining managed account shareholders may also incur additional transaction costs or adverse tax consequences from such trading activity. See also “Purchase and Sale of Fund Shares” in the Fund Summary. |
| Managed Funds | Thornburg Emerging Markets Managed Account Fund | Risks Affecting Specific Countries or Regions [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Risks Affecting Specific Countries or Regions – If a significant portion of the Fund’s assets is invested in issuers that are economically exposed to one country or region, the Fund’s share value may be more susceptible to the conditions and developments in that country or region, and potentially more volatile than the share value of a more geographically diversified fund. A specific country or region could also be adversely affected by conditions or developments arising in other countries. For example, the U.S. government could take actions to prohibit or restrict individuals or companies within the U.S. from purchasing or holding the shares of issuers in another country, which may limit the Fund’s ability to invest in that country or cause the Fund to have to sell investments in that country at less than desired prices. The nature and degree of the risks affecting a given country or region, and the extent of the Fund’s exposure to any such country or region, is expected to vary over time. |
| Managed Funds | Thornburg Emerging Markets Managed Account Fund | Risks Affecting Specific Issuers [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Risks Affecting Specific Issuers – The value of an equity security may decline in response to developments affecting the specific issuer of the security or obligation, even if the overall industry or economy is unaffected. These developments may include a variety of factors, including but not limited to management issues or other corporate disruption, a decline in revenues or profitability, an increase in costs, or an adverse effect on the issuer’s competitive position. |
| Managed Funds | Thornburg Emerging Markets Managed Account Fund | Small and Mid-Cap Company Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Small and Mid-Cap Company Risk – Investments in small-capitalization companies and mid-capitalization companies may involve additional risks, which may be relatively higher with smaller companies. These additional risks may result from limited product lines, more limited access to markets and financial resources, greater vulnerability to competition and changes in markets, lack of management depth, increased volatility in share price, and possible difficulties in valuing or selling these investments. Additional information about Fund investments, investment strategies and risks of investing in the Fund appears beginning on page 25 of the Prospectus. |
| Managed Funds | Thornburg Emerging Markets Managed Account Fund | Emerging Markets Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Emerging Markets Risk – The risks which may affect investments in foreign issuers (see “Foreign Investment Risk,” below) may be more pronounced for investments in emerging markets because the economies of those markets are usually less diversified, communications, transportation and economic infrastructures are less developed, and emerging markets ordinarily have less established legal, political, business and social frameworks. At times the prices of equity securities of an emerging markets issuer may be extremely volatile. An issuer domiciled in an emerging market may be similarly affected by these emerging markets risks to the extent that the issuer conducts its business in emerging markets. |
| Managed Funds | Thornburg Emerging Markets Managed Account Fund | Risk Lose Money [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Accordingly, the loss of money is a risk of investing in the Fund. |
| Managed Funds | Thornburg Emerging Markets Managed Account Fund | Risk Not Insured [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | An investment in the Fund is not a deposit in any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. |
| Managed Funds | Thornburg Emerging Markets Managed Account Fund | Risk Nondiversified Status [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Non-diversification Risk – The Fund is a non-diversified investment company, which means that it may invest a greater proportion of its assets in the securities of a single issuer. This may be riskier, because a default or other adverse condition affecting such an issuer could cause the Fund’s share price to decline to a greater degree. |
| Managed Funds | Thornburg High Income Bond Managed Account Fund | Credit Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Credit Risk – If obligations held by the Fund are downgraded by ratings agencies or go into default, or if management action, legislation or other government action reduces the ability of issuers to pay principal and interest when due, the value of those obligations may decline and the Fund’s share value and the dividends paid by the Fund may be reduced. Because the ability of an issuer of a lower-rated or unrated obligation to pay principal and interest when due is typically less certain than for an issuer of a higher-rated obligation, lower-rated and unrated obligations are generally more vulnerable than higher- rated obligations to default, to ratings downgrades, and to liquidity risk. Debt obligations backed by so-called “subprime” mortgages may also be subject to a greater risk of default or downgrade. Debt obligations issued by the U.S. government or its agencies, instrumentalities and government sponsored enterprises are also subject to credit risk. Securities backed by the full faith and credit of the U.S. government, such as U.S. Treasury obligations, are commonly regarded as having small exposure to credit risk. Obligations of certain U.S. agencies, instrumentalities and enterprises (sometimes referred to as “agency obligations”) are not direct obligations of the U.S. government, may not be backed by the full faith and credit of the U.S. government, and may have a greater exposure to credit risk. |
| Managed Funds | Thornburg High Income Bond Managed Account Fund | Cybersecurity and Operational Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Cybersecurity and Operational Risk – Operational failures, cyber-attacks or other disruptions that affect the Fund’s service providers, the Fund’s counterparties, other market participants or the issuers of securities held by the Fund may adversely affect the Fund and its shareholders, including by causing losses for the Fund or impairing Fund operations. The rapid development and increasingly widespread use of artificial intelligence, including machine learning technology and generative artificial intelligence such as ChatGPT, could exacerbate these risks. |
| Managed Funds | Thornburg High Income Bond Managed Account Fund | Foreign Currency Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Foreign Currency Risk – Fluctuations in currency exchange rates can adversely affect the value of the Fund’s foreign investments. Such fluctuations may occur for a number of reasons, including market and economic conditions, or a government’s decision to devalue its currency or impose currency controls. |
| Managed Funds | Thornburg High Income Bond Managed Account Fund | Foreign Investment Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Foreign Investment Risk – Investments in the debt obligations of foreign issuers may involve risks including adverse fluctuations in currency exchange rates, political instability, confiscations, taxes or restrictions on currency exchange, difficulty in selling foreign investments, and reduced legal protection. In addition, some foreign government debt obligations may be subject to default, delays in payment, adverse legislation or government action, or could be downgraded by ratings agencies. |
| Managed Funds | Thornburg High Income Bond Managed Account Fund | Liquidity Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Liquidity Risk – Due to a lack of demand in the marketplace or other factors, the Fund may not be able to sell some or all of its investments promptly, or may only be able to sell investments at less than desired prices. The market for lower-rated and unrated debt obligations (including particularly “junk” or “high yield” bonds) and debt obligations backed by so-called “subprime” mortgages may be less liquid than the market for other obligations, making it difficult for the Fund to value its investment in a lower-rated or unrated obligation or to sell the investment in a timely manner or at an acceptable price. |
| Managed Funds | Thornburg High Income Bond Managed Account Fund | Management Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Management Risk – The Fund is an actively managed portfolio, and the value of the Fund may be reduced if Thornburg pursues unsuccessful investments or fails to correctly identify risks affecting the broad economy or specific issuers in which the Fund invests. |
| Managed Funds | Thornburg High Income Bond Managed Account Fund | Market and Economic Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Market and Economic Risk – The value of the Fund’s investments may decline and its share value may be reduced due to changes in general economic and market conditions. This effect is typically more pronounced for lower-rated and unrated debt obligations (including particularly “junk” or “high yield” bonds), the value of which may fluctuate more significantly in response to poor economic growth or other changes in market conditions, political, economic, legal, and technological developments. |
| Managed Funds | Thornburg High Income Bond Managed Account Fund | Redemption Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Redemption Risk – Fund shares may only be redeemed by Thornburg on behalf of separately managed accounts or by certain managed account program sponsors and not by individual investors. If a significant percentage of the Fund’s shares is owned or controlled by a single managed account shareholder, the Fund is subject to the risk that a redemption by that managed account shareholder of all or a large portion of its shares may require the Fund to sell securities at less than desired prices, and the Fund’s remaining managed account shareholders may also incur additional transaction costs or adverse tax consequences from such trading activity. See also “Purchase and Sale of Fund Shares” in the Fund Summary. |
| Managed Funds | Thornburg High Income Bond Managed Account Fund | Risks Affecting Specific Issuers [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Risks Affecting Specific Issuers – The value of a debt obligation may decline in response to developments affecting the specific issuer of the obligation or security, even if the overall industry or economy is unaffected. These developments may include a variety of factors, including but not limited to management issues or other corporate disruption, a decline in revenues or profitability, an increase in costs, or an adverse effect on the issuer’s competitive position. |
| Managed Funds | Thornburg High Income Bond Managed Account Fund | High Yield Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | High Yield Risk – Debt obligations that are rated below investment grade and unrated obligations of similar credit quality (commonly referred to as “junk” or “high yield” bonds) may have a substantial risk of loss. These obligations are generally considered to be speculative with respect to the issuer’s ability to pay interest and principal when due. These obligations may be subject to greater price volatility than investment grade obligations, and their prices may decline significantly in periods of general economic difficulty or in response to adverse publicity, changes in investor perceptions or other factors. These obligations may also be subject to greater liquidity risk. |
| Managed Funds | Thornburg High Income Bond Managed Account Fund | Interest Rate Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Interest Rate Risk – When interest rates increase, the value of the Fund’s investments may decline and the Fund’s share value may be reduced. This effect is typically more pronounced for intermediate and longer-term obligations. This effect is also typically more pronounced for mortgage- and other asset-backed securities, the value of which may fluctuate more significantly in response to interest rate changes. When interest rates decrease, the Fund’s dividends may decline. |
| Managed Funds | Thornburg High Income Bond Managed Account Fund | Prepayment and Extension Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Prepayment and Extension Risk – When market interest rates decline, certain debt obligations held by the Fund may be repaid more quickly than anticipated, requiring the Fund to reinvest the proceeds of those repayments in obligations which bear a lower interest rate. Conversely, when market interest rates increase, certain debt obligations held by the Fund may be repaid more slowly than anticipated, causing assets of the Fund to remain invested in relatively lower yielding obligations. These risks may be more pronounced for the Fund’s investments in mortgage-backed and asset-backed securities. |
| Managed Funds | Thornburg High Income Bond Managed Account Fund | U.S. Government Obligations Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | U.S. Government Obligations Risk – U.S. government obligations are subject to the same risks affecting other debt obligations. Although securities backed by the full faith credit of the U.S. government are commonly regarded as having relatively less risk of default, it is possible that the U.S. government may be unwilling or unable to repay principal and interest when due and may require that the terms for payment be renegotiated. Further obligations that are backed by the full faith and credit of the U.S. government remain subject to the other general risks applicable to debt obligations, such as market risks, liquidity risks, and interest rate risks, and may be subject to ratings downgrades. U.S. government obligations also include obligations of U.S. government agencies, instrumentalities, and government-sponsored enterprises, commonly referred to as “agency obligations.” Some agency obligations are backed by the full faith and credit of the U.S. government, but other agency obligations have no specific backing or only limited support from the agency’s authority to borrow from the U.S. government or the discretionary authority of the Treasury to purchase obligations of the issuing agency. Additional information about Fund investments, investment strategies and risks of investing in the Fund appears beginning on page 25 of the Prospectus. |
| Managed Funds | Thornburg High Income Bond Managed Account Fund | Derivatives Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Derivatives Risk – The Fund’s investments in derivative instruments involve the risks associated with the securities or other assets underlying those derivatives and also may involve risks different or greater than the risks affecting the underlying assets, including that such instruments may be less liquid that other investments and may be more difficult to value. The Fund’s use of futures contracts exposes the Fund to the risk of loss caused by unanticipated market movements affecting the value of the underlying asset. If those movements are significant enough, the negative impact on the Fund’s asset value could be disproportionately large compared to the size of the Fund’s investment in the futures contract, and could even cause the Fund to lose more than the principal amount invested in such contracts. The Fund’s use of credit default swaps may increase the Fund’s overall credit risk because the Fund has exposure not only to the issuer of the underlying obligation, but also to the risk that the swap’s counterparty will default or otherwise fail to fulfill its obligations under the swap. While the Fund’s use of currency forward contracts is intended to reduce losses associated with changes in the value of foreign currencies, those same currency forward contracts could also have the effect of reducing or eliminating gains that the Fund would have otherwise realized had it not hedged the currency exposure. Furthermore, as with credit default swaps, the Fund’s use of currency forward contracts exposes the Fund to the credit risks of the contract’s counterparty. |
| Managed Funds | Thornburg High Income Bond Managed Account Fund | Structured Products Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Structured Products Risk – The Fund may invest in collateralized debt obligations (“CDOs”), which are securities backed by, or represent interests in, an underlying pool of assets. CDOs are typically issued in multiple “tranches,” each of which represents a portion of the full economic interest in the underlying assets, and each of which is issued at a specific fixed or floating interest rate. Principal payments received on the underlying pool of assets are often applied to each tranche in the order of its stated maturity, so that none of the principal payments received in a given period will be distributed to a particular tranche of the CDO until all other, more senior tranches are paid in full for that period. While all CDOs are subject to the risks that affect debt obligations generally, the relative riskiness of the Fund’s investment in a CDO will depend largely on the type of collateral in the underlying pool of assets and the tranche of the CDO in which the Fund invests. If, for example, the Fund is invested in a more junior tranche of a CDO, there is a greater risk that distributions from the underlying pool of assets will be insufficient to pay the Fund after all more senior tranches have been paid. Similarly, a CDO backed by less creditworthy assets, such as a CMO or a REMIC backed primarily by subprime mortgages, a CLO backed primarily by below investment grade loans, or a CBO backed primarily by below investment grade bonds, will generally present greater risks for the Fund, because the underlying assets are more likely to default or be downgraded, and the CDO securities themselves are more likely to be harder to value and less liquid. Additionally, with all CDOs, there is a risk that the manager of the special purpose entity that holds the underlying assets may fail in its management responsibilities, which may in turn delay or disrupt the payment of distributions to the Fund. |
| Managed Funds | Thornburg High Income Bond Managed Account Fund | Emerging Markets Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Emerging Markets Risk – The risks which may affect investments in foreign issuers (see “Foreign Investment Risk,” below) may be more pronounced for investments in emerging markets, also known as developing countries, because the economies of those markets are usually less diversified, communications, transportation and economic infrastructures are less developed, and emerging markets ordinarily have less established legal, political, business and social frameworks. At times the prices of debt obligations of an issuer in an emerging market may be extremely volatile. An issuer in a developed country may be similarly affected by these emerging markets risks to the extent that the issuer conducts its business in emerging markets. |
| Managed Funds | Thornburg High Income Bond Managed Account Fund | Bank Loans Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Bank Loans Risk – investments in corporate loans made by commercial banks and other financial institutions involve the associated with investments in other types of debt obligations, including credit risk, interest rate risk, liquidity risk, market and economic risk, and prepayment and extension risk (see those risk discussions below). Investments in such loans may also involve additional risks, including: (a) the risk that the loan is not secured by any collateral, or that the value of the collateral securing a loan may decline, be insufficient to meet the obligations of the borrower, or be difficult to liquidate; (b) the risk that a bankruptcy or other court proceeding could delay or limit the ability to collect the principal and interest payments on a loan or adversely affect the Fund’s right to access any collateral securing the loan; (c) increased liquidity risk due to the fact that many such loans are subject to legal or contractual restrictions on resales; (d) exposure to the credit risk of both the underlying borrower and the bank or other financial institution that is administering the loan; (e) the risk that there is limited public information available regarding the loan and the relevant borrower(s); and (f) the risk that the Fund’s sales of bank loans take longer than seven days to settle, in which case the sale proceeds may not be available to meet shareholder redemptions and the Fund may have to sell other investments at a loss to meet those redemptions. Additionally, bank loans may not be considered “securities” and may, therefore, not benefit from the protections of federal securities laws. These risks may be more significant for investments in loans involving so-called “subprime” borrowers, including borrowers that have substantial other debts outstanding or a poor credit history |
| Managed Funds | Thornburg High Income Bond Managed Account Fund | Foreign Government Obligations Risks [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Foreign Government Obligations Risks – Debt obligations may be issued by foreign governments and their agencies and instrumentalities, including the governments of emerging markets and “supra-national” entities such as the International Bank for Reconstruction and Development. The Fund’s investments in these foreign debt obligations may be denominated in U.S. dollars or in foreign currencies. These securities, even if denominated in U.S. dollars, may be affected significantly by fluctuations in the value of foreign currencies, and the value of these securities in U.S. dollars may decline even if the securities increase in value in their home country. The governmental issuers of these debt obligations may be less willing or able than the U.S. to repay principal and interest when due, and they may require that the terms for payment be renegotiated. In some countries there may be political instability or insufficient government supervision of markets, and the legal protections for the Fund’s investments could be subject to unfavorable judicial or administrative changes. These risks may be more pronounced for the Fund’s investments in debt obligations issued by emerging markets. |
| Managed Funds | Thornburg High Income Bond Managed Account Fund | Market Capitalization Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Market Capitalization Risk – To the extent the Fund invests in debt securities of micro-, small-, mid-, or large-cap issuers, it takes on the associated risks, and issuers of different market capitalizations tend to go in and out of favor based on market and economic conditions. Micro-, small-, or mid-cap issuers may have additional risks that result from limited product lines, more limited access to markets and financial resources, greater vulnerability to competition and changes in markets, lack of management depth, increased volatility, and possible difficulties in valuing or selling these investments. Large-cap issuers may be unable to respond as quickly to market changes and opportunities and may grow at a slower rate. During a period when issuers of a particular market capitalization fall behind other types of investments, the Fund’s performance could be impacted. |
| Managed Funds | Thornburg High Income Bond Managed Account Fund | Risks Affecting Mortgage-Backed Securities and Asset-Backed Securities [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Risks Affecting Mortgage-Backed Securities and Asset-Backed Securities – Mortgage-backed securities are debt obligations, and are subject to the risks that affect debt obligations generally and which may adversely affect the value of mortgage-backed securities held by the Fund, including credit risk, interest rate risk, market and liquidity risks, prepayment risk and extension, and management risk. Because mortgage-backed securities represent interests in underlying mortgages, mortgage-backed securities are subject to the risks associated with those underlying mortgages, including delays or defaults in payments on those mortgages. During periods of declining interest rates, more mortgagors can be expected to prepay the remaining principal on their mortgages before the mortgages’ scheduled maturity dates, reducing the value of mortgage-backed securities held by the Fund, and lowering the Fund’s yield as it reinvests the prepayment proceeds at the lower prevailing interest rates. Conversely, during periods of rising interest rates, the rate of prepayment on the underlying mortgages can be expected to slow, and the Fund will not have those additional prepayment proceeds to invest in other securities at the higher prevailing interest rates. While mortgage-backed securities issued by non-governmental issuers are often supported by some type of insurance or guarantee to enhance the credit of the issuing party, there is no assurance that the private insurer or guarantor will meet its obligations. Additionally, the trust or other entity that has been organized to administer the pool of mortgages may fail to make distribution payments to investors or otherwise perform poorly. Furthermore, such mortgage-backed securities may be harder to value and less liquid than mortgage-backed securities issued by a government or government agency. As with mortgage-backed securities, asset-backed securities are subject to the risks affecting debt obligations generally and which may adversely affect the value of asset-backed securities, held by the Fund, including credit risk, interest rate risk, market and liquidity risks, prepayment and extension risk, and management risk. These securities are subject to the risk of default by the issuer of the security and by the borrowers of the underlying loans in the pool. As with mortgage-backed securities, the market value and expected yield of asset-backed securities will vary in response to changes in prevailing interest rates and the rate of prepayment on the underlying loans. |
| Managed Funds | Thornburg High Income Bond Managed Account Fund | Risk Lose Money [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Accordingly, the loss of money is a risk of investing in the Fund. |
| Managed Funds | Thornburg High Income Bond Managed Account Fund | Risk Not Insured [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | An investment in the Fund is not a deposit in any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. |
| Managed Funds | Thornburg High Income Bond Managed Account Fund | Risk Nondiversified Status [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Non-diversification Risk – The Fund is a non-diversified investment company, which means that it may invest a greater proportion of its assets in the securities of a single issuer. This may be riskier, because a default or other adverse condition affecting such an issuer could cause the Fund’s share price to decline to a greater degree. |
| Managed Funds | Thornburg Investment Grade Bond Managed Account Fund | Credit Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Credit Risk – If obligations held by the Fund are downgraded by ratings agencies or go into default, or if management action, legislation or other government action reduces the ability of issuers to pay principal and interest when due, the value of those obligations may decline and the Fund’s share value and the dividends paid by the Fund may be reduced. Because the ability of an issuer of a lower-rated or unrated obligation to pay principal and interest when due is typically less certain than for an issuer of a higher-rated obligation, lower-rated and unrated obligations are generally more vulnerable than higher- rated obligations to default, to ratings downgrades, and to liquidity risk. Debt obligations backed by so-called “subprime” mortgages may also be subject to a greater risk of default or downgrade. Debt obligations issued by the U.S. government or its agencies, instrumentalities and government sponsored enterprises are also subject to credit risk. Securities backed by the full faith and credit of the U.S. government, such as U.S. Treasury obligations, are commonly regarded as having small exposure to credit risk. Obligations of certain U.S. agencies, instrumentalities and enterprises (sometimes referred to as “agency obligations”) are not direct obligations of the U.S. government, may not be backed by the full faith and credit of the U.S. government, and may have a greater exposure to credit risk. |
| Managed Funds | Thornburg Investment Grade Bond Managed Account Fund | Cybersecurity and Operational Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Cybersecurity and Operational Risk – Operational failures, cyber-attacks or other disruptions that affect the Fund’s service providers, the Fund’s counterparties, other market participants, or the issuers of securities held by the Fund may adversely affect the Fund and its shareholders, including by causing losses for the Fund or impairing Fund operations. The rapid development and increasingly widespread use of artificial intelligence, including machine learning technology and generative artificial intelligence such as ChatGPT, could exacerbate these risks. |
| Managed Funds | Thornburg Investment Grade Bond Managed Account Fund | Foreign Currency Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Foreign Currency Risk – Fluctuations in currency exchange rates can adversely affect the value of the Fund’s foreign investments. Such fluctuations may occur for a number of reasons, including market and economic conditions, or a government’s decision to devalue its currency or impose currency controls. |
| Managed Funds | Thornburg Investment Grade Bond Managed Account Fund | Foreign Investment Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Foreign Investment Risk – Investments in the debt obligations of foreign issuers may involve risks including adverse fluctuations in currency exchange rates, political instability, confiscations, taxes or restrictions on currency exchange, difficulty in selling foreign investments, and reduced legal protection. In addition, some foreign government debt obligations may be subject to default, delays in payment, adverse legislation or government action, or could be downgraded by ratings agencies. |
| Managed Funds | Thornburg Investment Grade Bond Managed Account Fund | Liquidity Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Liquidity Risk – Due to a lack of demand in the marketplace or other factors, the Fund may not be able to sell some or all of its investments promptly, or may only be able to sell investments at less than desired prices. The market for lower-rated and unrated debt obligations and debt obligations backed by so-called “subprime” mortgages may be less liquid than the market for other obligations, making it difficult for the Fund to value its investment in a lower-rated or unrated obligation or to sell the investment in a timely manner or at an acceptable price. |
| Managed Funds | Thornburg Investment Grade Bond Managed Account Fund | Management Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Management Risk – The Fund is an actively managed portfolio, and the value of the Fund may be reduced if Thornburg pursues unsuccessful investments or fails to correctly identify risks affecting the broad economy or specific issuers in which the Fund invests. |
| Managed Funds | Thornburg Investment Grade Bond Managed Account Fund | Market and Economic Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Market and Economic Risk – The value of the Fund’s investments may decline and its share value may be reduced due to changes in general economic and market conditions. This effect is typically more pronounced for lower-rated and unrated debt obligations, the value of which may fluctuate more significantly in response to poor economic growth or other changes in market conditions, political, economic, legal, and technological developments, and developments affecting specific issuers. |
| Managed Funds | Thornburg Investment Grade Bond Managed Account Fund | Redemption Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Redemption Risk – Fund shares may only be redeemed by Thornburg on behalf of separately managed accounts or by certain managed account program sponsors and not by individual investors. If a significant percentage of the Fund’s shares is owned or controlled by a single managed account shareholder, the Fund is subject to the risk that a redemption by that managed account shareholder of all or a large portion of its shares may require the Fund to sell securities at less than desired prices, and the Fund’s remaining managed account shareholders may also incur additional transaction costs or adverse tax consequences from such trading activity. See also “Purchase and Sale of Fund Shares” in the Fund Summary. |
| Managed Funds | Thornburg Investment Grade Bond Managed Account Fund | Risks Affecting Specific Issuers [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Risks Affecting Specific Issuers – The value of a debt obligation may decline in response to developments affecting the specific issuer of the obligation or security, even if the overall industry or economy is unaffected. These developments may include a variety of factors, including but not limited to management issues or other corporate disruption, a decline in revenues or profitability, an increase in costs, or an adverse effect on the issuer’s competitive position. |
| Managed Funds | Thornburg Investment Grade Bond Managed Account Fund | Foreign Government Obligations Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Foreign Government Obligations Risk – Debt obligations may be issued by foreign governments and their agencies and instrumentalities, including the governments of emerging markets and “supra-national” entities such as the International Bank for Reconstruction and Development. The Fund’s investments in these foreign debt obligations may be denominated in U.S. dollars or in foreign currencies. These securities, even if denominated in U.S. dollars, may be affected significantly by fluctuations in the value of foreign currencies, and the value of these securities in U.S. dollars may decline even if the securities increase in value in their home country. The governmental issuers of these debt obligations may be less willing or able than the U.S. to repay principal and interest when due, and they may require that the terms for payment be renegotiated. In some countries there may be political instability or insufficient government supervision of markets, and the legal protections for the Fund’s investments could be subject to unfavorable judicial or administrative changes. These risks may be more pronounced for the Fund’s investments in debt obligations issued by emerging markets. |
| Managed Funds | Thornburg Investment Grade Bond Managed Account Fund | Interest Rate Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Interest Rate Risk – When interest rates increase, the value of the Fund’s investments may decline and the Fund’s share value may be reduced. This effect is typically more pronounced for intermediate and longer-term obligations. This effect is also typically more pronounced for mortgage- and other asset-backed securities, the value of which may fluctuate more significantly in response to interest rate changes. When interest rates decrease, the Fund’s dividends may decline. |
| Managed Funds | Thornburg Investment Grade Bond Managed Account Fund | Prepayment and Extension Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Prepayment and Extension Risk – When market interest rates decline, certain debt obligations held by the Fund may be repaid more quickly than anticipated, requiring the Fund to reinvest the proceeds of those repayments in obligations which bear a lower interest rate. Conversely, when market interest rates increase, certain debt obligations held by the Fund may be repaid more slowly than anticipated, causing assets of the Fund to remain invested in relatively lower yielding obligations. These risks may be more pronounced for the Fund’s investments in mortgage-backed and asset-backed securities. |
| Managed Funds | Thornburg Investment Grade Bond Managed Account Fund | U.S. Government Obligations Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | U.S. Government Obligations Risk – U.S. government obligations are subject to the same risks affecting other debt obligations. Although securities backed by the full faith credit of the U.S. government are commonly regarded as having relatively less risk of default, it is possible that the U.S. government may be unwilling or unable to repay principal and interest when due and may require that the terms for payment be renegotiated. Further obligations that are backed by the full faith and credit of the U.S. government remain subject to the other general risks applicable to debt obligations, such as market risks, liquidity risks, and interest rate risks, and may be subject to ratings downgrades. U.S. government obligations also include obligations of U.S. government agencies, instrumentalities, and government-sponsored enterprises, commonly referred to as “agency obligations.” Some agency obligations are backed by the full faith and credit of the U.S. government, but other agency obligations have no specific backing or only limited support from the agency’s authority to borrow from the U.S. government or the discretionary authority of the Treasury to purchase obligations of the issuing agency. Additional information about Fund investments, investment strategies and risks of investing in the Fund appears beginning on page 25 of the Prospectus. |
| Managed Funds | Thornburg Investment Grade Bond Managed Account Fund | Derivatives Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Derivatives Risk – The Fund’s investments in derivative instruments involve the risks associated with the securities or other assets underlying those derivatives and also may involve risks different or greater than the risks affecting the underlying assets, including that such instruments may be less liquid that other investments and may be more difficult to value. The Fund’s use of futures contracts exposes the Fund to the risk of loss caused by unanticipated market movements affecting the value of the underlying asset. If those movements are significant enough, the negative impact on the Fund’s asset value could be disproportionately large compared to the size of the Fund’s investment in the futures contract, and could even cause the Fund to lose more than the principal amount invested in such contracts. While the Fund’s use of currency forward contracts is intended to reduce losses associated with changes in the value of foreign currencies, those same currency forward contracts could also have the effect or reducing or eliminating gains that the Fund would have otherwise realized had it not hedged the currency exposure. Furthermore, currency forward contracts are over-the-counter instruments, meaning the Fund is subject to the risk that the counterparty to the forward contract will default or otherwise fail to fulfill its obligations. |
| Managed Funds | Thornburg Investment Grade Bond Managed Account Fund | Structured Products Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Structured Products Risk – The Fund may invest in collateralized debt obligations (“CDOs”), which are securities backed by, or represent interests in, an underlying pool of assets. CDOs are typically issued in multiple “tranches,” each of which represents a portion of the full economic interest in the underlying assets, and each of which is issued at a specific fixed or floating interest rate. Principal payments received on the underlying pool of assets are often applied to each tranche in the order of its stated maturity, so that none of the principal payments received in a given period will be distributed to a particular tranche of the CDO until all other, more senior tranches are paid in full for that period. While all CDOs are subject to the risks that affect debt obligations generally, the relative riskiness of the Fund’s investment in a CDO will depend largely on the type of collateral in the underlying pool of assets and the tranche of the CDO in which the Fund invests. If, for example, the Fund is invested in a more junior tranche of a CDO, there is a greater risk that distributions from the underlying pool of assets will be insufficient to pay the Fund after all more senior tranches have been paid. Similarly, a CDO backed by less creditworthy assets, such as a CMO or a REMIC backed primarily by subprime mortgages, a CLO backed primarily by below investment grade loans, or a CBO backed primarily by below investment grade bonds, will generally present greater risks for the Fund, because the underlying assets are more likely to default or be downgraded, and the CDO securities themselves are more likely to be harder to value and less liquid. Additionally, with all CDOs, there is a risk that the manager of the special purpose entity that holds the underlying assets may fail in its management responsibilities, which may in turn delay or disrupt the payment of distributions to the Fund. |
| Managed Funds | Thornburg Investment Grade Bond Managed Account Fund | Emerging Markets Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Emerging Markets Risk – The risks which may affect investments in foreign issuers (see “Foreign Investment Risk,” below) may be more pronounced for investments in emerging markets, also known as developing countries, because the economies of those markets are usually less diversified, communications, transportation and economic infrastructures are less developed, and emerging markets ordinarily have less established legal, political, business and social frameworks. At times the prices of debt obligations of an issuer in an emerging market may be extremely volatile. An issuer in a developed country may be similarly affected by these emerging markets risks to the extent that the issuer conducts its business in emerging markets. |
| Managed Funds | Thornburg Investment Grade Bond Managed Account Fund | Market Capitalization Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Market Capitalization Risk – To the extent the Fund invests in debt securities of micro-, small-, mid-, or large-cap issuers, it takes on the associated risks, and issuers of different market capitalizations tend to go in and out of favor based on market and economic conditions. Micro-, small-, or mid-cap issuers may have additional risks that result from limited product lines, more limited access to markets and financial resources, greater vulnerability to competition and changes in markets, lack of management depth, increased volatility, and possible difficulties in valuing or selling these investments. Large-cap issuers may be unable to respond as quickly to market changes and opportunities and may grow at a slower rate. During a period when issuers of a particular market capitalization fall behind other types of investments, the Fund’s performance could be impacted. |
| Managed Funds | Thornburg Investment Grade Bond Managed Account Fund | Risks Affecting Mortgage-Backed Securities and Asset-Backed Securities [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Risks Affecting Mortgage-Backed Securities and Asset-Backed Securities – Mortgage-backed securities are debt obligations, and are subject to the risks that affect debt obligations generally and which may adversely affect the value of mortgage-backed securities held by the Fund, including credit risk, interest rate risk, market and liquidity risks, prepayment risk and extension, and management risk. Because mortgage-backed securities represent interests in underlying mortgages, mortgage-backed securities are subject to the risks associated with those underlying mortgages, including delays or defaults in payments on those mortgages. During periods of declining interest rates, more mortgagors can be expected to prepay the remaining principal on their mortgages before the mortgages’ scheduled maturity dates, reducing the value of mortgage-backed securities held by the Fund, and lowering the Fund’s yield as it reinvests the prepayment proceeds at the lower prevailing interest rates. Conversely, during periods of rising interest rates, the rate of prepayment on the underlying mortgages can be expected to slow, and the Fund will not have those additional prepayment proceeds to invest in other securities at the higher prevailing interest rates. While mortgage-backed securities issued by non-governmental issuers are often supported by some type of insurance or guarantee to enhance the credit of the issuing party, there is no assurance that the private insurer or guarantor will meet its obligations. Additionally, the trust or other entity that has been organized to administer the pool of mortgages may fail to make distribution payments to investors or otherwise perform poorly. Furthermore, such mortgage-backed securities may be harder to value and less liquid than mortgage-backed securities issued by a government or government agency. As with mortgage-backed securities, asset-backed securities are subject to the risks affecting debt obligations generally and which may adversely affect the value of asset-backed securities, held by the Fund, including credit risk, interest rate risk, market and liquidity risks, prepayment and extension risk, and management risk. These securities are subject to the risk of default by the issuer of the security and by the borrowers of the underlying loans in the pool. As with mortgage-backed securities, the market value and expected yield of asset-backed securities will vary in response to changes in prevailing interest rates and the rate of prepayment on the underlying loans. |
| Managed Funds | Thornburg Investment Grade Bond Managed Account Fund | Risk Lose Money [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Accordingly, the loss of money is a risk of investing in the Fund. |
| Managed Funds | Thornburg Investment Grade Bond Managed Account Fund | Risk Not Insured [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | An investment in the Fund is not a deposit in any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. |
| Managed Funds | Thornburg Investment Grade Bond Managed Account Fund | Risk Nondiversified Status [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Non-diversification Risk – The Fund is a non-diversified investment company, which means that it may invest a greater proportion of its assets in the securities of a single issuer. This may be riskier, because a default or other adverse condition affecting such an issuer could cause the Fund’s share price to decline to a greater degree. |
| Managed Funds | Thornburg Municipal Managed Account Fund | Credit Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Credit Risk – If obligations held by the Fund are downgraded by ratings agencies or go into default, or if legislation or other government action reduces the ability of issuers to pay principal and interest when due, the value of those obligations may decline and the Fund’s share value and the dividends paid by the Fund may be reduced. Because the ability of an issuer of a lower-rated or unrated obligation to pay principal and interest when due is typically less certain than for an issuer of a higher-rated obligation, lower-rated and unrated obligations are generally more vulnerable than higher-rated obligations to default, to ratings downgrades, and to liquidity risk. For example, municipal leases held by the Fund may be subject to non-appropriation provisions which permit governmental agencies or issuers to discontinue payments to the Fund under the municipal leases. |
| Managed Funds | Thornburg Municipal Managed Account Fund | Cybersecurity and Operational Risk [Member] | |
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| Risk [Text Block] | Cybersecurity and Operational Risk – Operational failures, cyber-attacks or other disruptions that affect the Fund’s service providers, the Fund’s counterparties, other market participants or the issuers of securities held by the Fund may adversely affect the Fund and its shareholders, including by causing losses for the Fund or impairing Fund operations. The rapid development and increasingly widespread use of artificial intelligence, including machine learning technology and generative artificial intelligence such as ChatGPT, could exacerbate these risks. |
| Managed Funds | Thornburg Municipal Managed Account Fund | Liquidity Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Liquidity Risk – Due to a lack of demand in the marketplace or other factors, the Fund may not be able to sell promptly some or all of the obligations that it holds, or may only be able to sell obligations at less than desired prices. The market for lower-rated and unrated obligations (including particularly “junk” or “high yield” bonds) may be less liquid than the market for other obligations, making it difficult for the Fund to value its investment in a lower-rated or unrated obligation or to sell the investment in a timely manner or at an acceptable price. |
| Managed Funds | Thornburg Municipal Managed Account Fund | Management Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Management Risk – The Fund is an actively managed portfolio, and the value of the Fund may be reduced if Thornburg pursues unsuccessful investments or fails to correctly identify risks affecting the broad economy or specific issuers in which the Fund invests. |
| Managed Funds | Thornburg Municipal Managed Account Fund | Market and Economic Risk [Member] | |
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| Risk [Text Block] | Market and Economic Risk – The value of the Fund’s investments may decline and its share value may be reduced due to changes in general economic and market conditions. This effect is typically more pronounced for the Fund’s investments in lower-rated and unrated municipal obligations (including particularly “junk” or “high yield” bonds), the value of which may fluctuate more significantly in response to poor economic growth or other changes in market conditions, political, economic, legal, and technological developments, and developments affecting specific issuers. |
| Managed Funds | Thornburg Municipal Managed Account Fund | Redemption Risk [Member] | |
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| Risk [Text Block] | Redemption Risk – Fund shares may only be redeemed by Thornburg on behalf of separately managed accounts or by certain managed account program sponsors and not by individual investors. If a significant percentage of the Fund’s shares is owned or controlled by a single managed account shareholder, the Fund is subject to the risk that a redemption by that managed account shareholder of all or a large portion of its shares may require the Fund to sell securities at less than desired prices, and the Fund’s remaining managed account shareholders may also incur additional transaction costs or adverse tax consequences from such trading activity. See also “Purchase and Sale of Fund Shares” in the Fund Summary. |
| Managed Funds | Thornburg Municipal Managed Account Fund | High Yield Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | High Yield Risk – Debt obligations that are rated below investment grade and unrated obligations of similar credit quality (commonly referred to as “junk” or “high yield” bonds) may have a substantial risk of loss. These obligations are generally considered to be speculative with respect to the issuer’s ability to pay interest and principal when due. These obligations may be subject to greater price volatility than investment grade obligations, and their prices may decline significantly in periods of general economic difficulty or in response to adverse publicity, changes in investor perceptions or other factors. These obligations may also be subject to greater liquidity risk. |
| Managed Funds | Thornburg Municipal Managed Account Fund | Interest Rate Risk [Member] | |
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| Risk [Text Block] | Interest Rate Risk – When interest rates increase, the value of the Fund’s investments may decline and the Fund’s share value may be reduced. This effect is typically more pronounced for intermediate and longer-term obligations. When interest rates decrease, the Fund’s dividends may decline. Decreases in market interest rates may also result in prepayments of obligations the Fund acquires, requiring the Fund to reinvest at lower interest rates. |
| Managed Funds | Thornburg Municipal Managed Account Fund | Tax Risk [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Tax Risk – The income on the Fund’s municipal obligations could become subject to federal income or state income tax due to noncompliant conduct by issuers, unfavorable legislation or litigation or adverse interpretations by regulatory authorities. All or a portion of the Fund’s distributions that are exempt from regular federal income tax may nevertheless be taken into account for purposes of the federal AMT and state income tax. Additional information about Fund investments, investment strategies and risks of investing in the Fund appears beginning on page 25 of the Prospectus. |
| Managed Funds | Thornburg Municipal Managed Account Fund | Risk Lose Money [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Accordingly, the loss of money is a risk of investing in the Fund. |
| Managed Funds | Thornburg Municipal Managed Account Fund | Risk Not Insured [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | An investment in the Fund is not a deposit in any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. |
| Managed Funds | Thornburg Municipal Managed Account Fund | Risk Nondiversified Status [Member] | |
| Prospectus [Line Items] | |
| Risk [Text Block] | Non-diversification Risk – The Fund is a non-diversified investment company, which means that it may invest a greater proportion of its assets in the securities of a single issuer. This may be riskier, because a default or other adverse condition affecting such an issuer could cause the Fund’s share price to decline to a greater degree. |