Alger Responsible Investing Fund Investment Risks - Class I Shares [Member] - Alger Responsible Investing Fund	Oct. 31, 2025
Investment Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	Investment Risk – An investment in the Fund is subject to investment risk, including the possible loss of the entire principal amount that you invest.
Market Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	Market Risk – Your investment in Fund shares represents an indirect investment in the securities owned by the Fund. The value of these securities, like other investments, may move up or down, sometimes rapidly and unpredictably. Your Fund shares at any point in time may be worth less than what you invested, even after taking into account the reinvestment of Fund dividends and distributions. Local, regional or global events such as environmental or natural disasters, war, terrorism, pandemics, outbreaks of infectious diseases, and similar public health threats, trade disputes and changes in trade regulations, civil unrest, recessions, or other events could have a significant impact on the Fund and its investments.
Equity Securities Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	Equity Securities Risk – As with any fund that invests in stocks, your investment will fluctuate in value, and the loss of your investment is a risk of investing. The Fund’s price per share will fluctuate due to changes in the market prices of its investments. Also, the Fund’s investments may not grow as fast as the rate of inflation and stocks tend to be more volatile than some other investments you could make, such as bonds.
Growth Securities Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	Growth Securities Risk – Prices of growth stocks tend to be higher in relation to their companies’ earnings and may be more sensitive to market, political and economic developments than other stocks, making their prices more volatile. An investment in the Fund may be better suited to investors who seek long-term capital growth and can tolerate fluctuations in their investment’s value.
Environmental Social and or Governance Sustainability-Related Securities Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	Environmental, Social and/or Governance Sustainability-Related Securities Risk – The Fund’s ESG investment criteria may result in the selection or exclusion of securities of certain issuers for reasons other than financial performance, and carries the risk that the Fund’s investment returns may underperform funds that do not utilize an ESG investment strategy. The application of this strategy may affect the Fund’s investment exposure to certain companies, sectors, regions, countries or types of investments, which could negatively impact the Fund’s performance depending on whether such investments are in or out of favor. Applying ESG criteria to investment decisions is qualitative and subjective by nature, and there is no guarantee that the criteria utilized by the Manager or any judgment exercised by the Manager will reflect the beliefs or values of any particular investor. ESG standards differ by region and industry, and a company’s ESG practices or the Manager’s assessment of a company’s ESG practices may change over time.
Sector Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	Sector Risk – The Fund may have a significant portion of its assets invested in securities of companies conducting business within a single sector, as defined by third party sources. Companies in the same sector may be similarly affected by economic, regulatory, political or market events or conditions, which may make the Fund more vulnerable to unfavorable developments in that sector than a fund that has a more diversified portfolio. Generally, the more broadly the Fund invests, the more it spreads risk and potentially reduces the risks of loss and volatility.
Information Technology Sector Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	●Information Technology Sector Risk – The Fund may have a significant portion of its assets invested in securities of technology-related companies. Therefore, the Fund may be more susceptible to particular risks that may affect companies in the information technology sector and technology-related sectors than if it were invested in a wider variety of companies in unrelated sectors. At times, the performance of such companies will lag the performance of other industries or the broader market as a whole. Certain technology related companies may face special risks that their products or services may not prove to be commercially successful. Technology related companies are also strongly affected by worldwide scientific or technological developments. As a result, their products may rapidly become obsolete. Such companies are also often subject to governmental regulation and may, therefore, be adversely affected by governmental policies. These factors may lead to limited earnings and/or failing profit margins. As a result, the value of technology related companies’ securities may fall or fail to rise. Many technology related companies’ securities have historically been more volatile than other securities, especially over the short term.
Consumer Discretionary Sector Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	●Consumer Discretionary Sector Risk – The consumer discretionary sector may be affected by changes in domestic and international economies, exchange and interest rates, competition, consumers’ disposable income, consumer preferences, social trends and marketing campaigns.
Communication Services Sector Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	●Communication Services Sector Risk – Communication services companies are particularly vulnerable to the potential obsolescence of products and services due to technological advancement and the innovation of competitors. Companies in the communication services sector may also be affected by other competitive pressures, such as pricing competition, as well as research and development costs, substantial capital requirements and government regulation. Additionally, fluctuating domestic and international demand, shifting demographics and often unpredictable changes in consumer tastes can drastically affect a communication services company’s profitability. While all companies may be susceptible to network security breaches, certain companies in the communication services sector may be particular targets of hacking and potential theft of proprietary or consumer information or disruptions in service, which could have a material adverse effect on their businesses.
Cash Position Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	Cash Position Risk – At times, the Fund may hold up to 15% of its net assets in cash (and cash equivalents), which may underperform relative to equity securities.
Risk Lose Money [Member]
Prospectus [Line Items]
Risk [Text Block]	The Fund’s share price may go down, which means you could lose money.
Risk Not Insured Depository Institution [Member]
Prospectus [Line Items]
Risk [Text Block]	An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Alger Responsible Investing Fund Investment Risks - Class I Shares [Member] - Alger Responsible Investing Fund

Oct. 31, 2025

Investment Risk – An investment in the Fund is subject to investment risk, including the possible loss of the entire principal amount that you invest.

Prospectus [Line Items]

Risk [Text Block]

Market Risk – Your investment in Fund shares represents an indirect investment in the securities owned by the Fund. The value of these securities, like other investments, may move up or down, sometimes rapidly and unpredictably. Your Fund shares at any point in time may be worth less than what you invested, even after taking into account the reinvestment of Fund dividends and distributions. Local, regional or global events such as environmental or natural disasters, war, terrorism, pandemics, outbreaks of infectious diseases, and similar public health threats, trade disputes and changes in trade regulations, civil unrest, recessions, or other events could have a significant impact on the Fund and its investments.

Equity Securities Risk [Member]

Prospectus [Line Items]

Risk [Text Block]

Equity Securities Risk – As with any fund that invests in stocks, your investment will fluctuate in value, and the loss of your investment is a risk of investing. The Fund’s price per share will fluctuate due to changes in the market prices of its investments. Also, the Fund’s investments may not grow as fast as the rate of inflation and stocks tend to be more volatile than some other investments you could make, such as bonds.

Growth Securities Risk [Member]

Prospectus [Line Items]

Risk [Text Block]

Growth Securities Risk – Prices of growth stocks tend to be higher in relation to their companies’ earnings and may be more sensitive to market, political and economic developments than other stocks, making their prices more volatile. An investment in the Fund may be better suited to investors who seek long-term capital growth and can tolerate fluctuations in their investment’s value.

Environmental Social and or Governance Sustainability-Related Securities Risk [Member]

Prospectus [Line Items]

Risk [Text Block]

Environmental, Social and/or Governance Sustainability-Related Securities Risk – The Fund’s ESG investment criteria may result in the selection or exclusion of securities of certain issuers for reasons other than financial performance, and carries the risk that the Fund’s investment returns may underperform funds that do not utilize an ESG investment strategy. The application of this strategy may affect the Fund’s investment exposure to certain companies, sectors, regions, countries or types of investments, which could negatively impact the Fund’s performance depending on whether such investments are in or out of favor. Applying ESG criteria to investment decisions is qualitative and subjective by nature, and there is no guarantee that the criteria utilized by the Manager or any judgment exercised by the Manager will reflect the beliefs or values of any particular investor. ESG standards differ by region and industry, and a company’s ESG practices or the Manager’s assessment of a company’s ESG practices may change over time.

Sector Risk [Member]

Prospectus [Line Items]

Risk [Text Block]

Sector Risk – The Fund may have a significant portion of its assets invested in securities of companies conducting business within a single sector, as defined by third party sources. Companies in the same sector may be similarly affected by economic, regulatory, political or market events or conditions, which may make the Fund more vulnerable to unfavorable developments in that sector than a fund that has a more diversified portfolio. Generally, the more broadly the Fund invests, the more it spreads risk and potentially reduces the risks of loss and volatility.

Information Technology Sector Risk [Member]

Prospectus [Line Items]

Risk [Text Block]

●Information Technology Sector Risk – The Fund may have a significant portion of its assets invested in securities of technology-related companies. Therefore, the Fund may be more susceptible to particular risks that may affect companies in the information technology sector and technology-related sectors than if it were invested in a wider variety of companies in unrelated sectors. At times, the performance of such companies will lag the performance of other industries or the broader market as a whole. Certain technology related companies may face special risks that their products or services may not prove to be commercially successful. Technology related companies are also strongly affected by worldwide scientific or technological developments. As a result, their products may rapidly become obsolete. Such companies are also often subject to governmental regulation and may, therefore, be adversely affected by governmental policies. These factors may lead to limited earnings and/or failing profit margins. As a result, the value of technology related companies’ securities may fall or fail to rise. Many technology related companies’ securities have historically been more volatile than other securities, especially over the short term.

Consumer Discretionary Sector Risk [Member]

Prospectus [Line Items]

Risk [Text Block]

●Consumer Discretionary Sector Risk – The consumer discretionary sector may be affected by changes in domestic and international economies, exchange and interest rates, competition, consumers’ disposable income, consumer preferences, social trends and marketing campaigns.

Communication Services Sector Risk [Member]

Prospectus [Line Items]

Risk [Text Block]

●Communication Services Sector Risk – Communication services companies are particularly vulnerable to the potential obsolescence of products and services due to technological advancement and the innovation of competitors. Companies in the communication services sector may also be affected by other competitive pressures, such as pricing competition, as well as research and development costs, substantial capital requirements and government regulation. Additionally, fluctuating domestic and international demand, shifting demographics and often unpredictable changes in consumer tastes can drastically affect a communication services company’s profitability. While all companies may be susceptible to network security breaches, certain companies in the communication services sector may be particular targets of hacking and potential theft of proprietary or consumer information or disruptions in service, which could have a material adverse effect on their businesses.

Cash Position Risk [Member]

Prospectus [Line Items]

Risk [Text Block]

Cash Position Risk – At times, the Fund may hold up to 15% of its net assets in cash (and cash equivalents), which may underperform relative to equity securities.

Risk Lose Money [Member]

Prospectus [Line Items]

Risk [Text Block]

The Fund’s share price may go down, which means you could lose money.

Risk Not Insured Depository Institution [Member]

Prospectus [Line Items]

Risk [Text Block]

An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.