v3.24.4
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Risk Return Abstract rr_RiskReturnAbstract  
Registrant Name dei_EntityRegistrantName PIONEER SHORT TERM INCOME FUND
Prospectus Date rr_ProspectusDate Dec. 31, 2024
Pioneer Short Term Income Fund  
Risk Return Abstract rr_RiskReturnAbstract  
Risk/Return [Heading] rr_RiskReturnHeading <span style="color:#000000;font-family:Arial Narrow;font-size:14pt;font-weight:bold;">Fund summary</span>
Objective [Heading] rr_ObjectiveHeading <span style="color:#000000;font-family:Arial;font-size:11pt;font-weight:bold;">Investment objective</span>
Objective, Primary [Text Block] rr_ObjectivePrimaryTextBlock A high level of current income to the extent consistent with a relatively high level of stability of principal.
Expense [Heading] rr_ExpenseHeading <span style="color:#000000;font-family:Arial;font-size:11pt;font-weight:bold;">Fees and expenses of the fund</span>
Expense Narrative [Text Block] rr_ExpenseNarrativeTextBlock This table describes the fees and expenses that you may pay if you buy, hold and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.Information about sales charge discounts is available from your investment professional and in the “Sales charges” section of the prospectus beginning on page 66, the “Intermediary defined sales charge waiver policies” section of the prospectus beginning on page 99, and the “Sales charges” section of the statement of additional information beginning on page 64. If you invest in Class K shares or Class Y shares through an investment professional or financial intermediary, that investment professional or financial intermediary may charge you a commission. Such commissions, if any, are not charged by the fund and are not reflected in the fee table or expense example below.
Shareholder Fees Caption [Text] rr_ShareholderFeesCaption <span style="color:#000000;font-family:Arial;font-size:9pt;font-weight:bold;">Shareowner fees</span> <div> </div><span style="color:#000000;font-family:Arial;font-size:9pt;">(fees paid directly from your investment)</span>
Operating Expenses Caption [Text] rr_OperatingExpensesCaption <span style="color:#000000;font-family:Arial;font-size:9pt;font-weight:bold;">Annual fund operating expenses</span> <div> </div><span style="color:#000000;font-family:Arial;font-size:9pt;">(expenses that you pay each year as a percentage of the value of your investment)</span>
Fee Waiver or Reimbursement over Assets, Date of Termination rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination <span style="font-family:Arial Narrow;font-size:8pt;">January 1, 2026</span>
Portfolio Turnover [Heading] rr_PortfolioTurnoverHeading <span style="color:#000000;font-family:Arial;font-size:11pt;font-weight:bold;">Portfolio turnover</span>
Portfolio Turnover [Text Block] rr_PortfolioTurnoverTextBlock The fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 40% of the average value of its portfolio.
Portfolio Turnover, Rate rr_PortfolioTurnoverRate 40.00%
Expense Example [Heading] rr_ExpenseExampleHeading <span style="color:#000000;font-family:Arial;font-size:9pt;font-weight:bold;">Example</span>
Expense Example Narrative [Text Block] rr_ExpenseExampleNarrativeTextBlock This example is intended to help you compare the cost of investing in the fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the fund for the time periods shown and then, except as indicated, redeem all of your shares at the end of those periods. It also assumes that (a) your investment has a 5% return each year and (b) the fund's total annual operating expenses remain the same except for year one (which considers the effect of the expense limitation). Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Expense Example by, Year, Caption [Text] rr_ExpenseExampleByYearCaption <span style="font-family:Arial Narrow;font-size:7pt;font-weight:bold;">If you redeem your shares</span><span style="font-family:Arial Narrow;font-size:7pt;font-weight:bold;">Number of years you own your shares</span>
Expense Example, No Redemption, By Year, Caption [Text] rr_ExpenseExampleNoRedemptionByYearCaption <span style="font-family:Arial Narrow;font-size:7pt;font-weight:bold;">If you do not redeem your shares</span><span style="font-family:Arial Narrow;font-size:7pt;font-weight:bold;">Number of years you own your shares</span>
Strategy [Heading] rr_StrategyHeading <span style="color:#000000;font-family:Arial;font-size:11pt;font-weight:bold;">Principal investment strategies</span>
Strategy Narrative [Text Block] rr_StrategyNarrativeTextBlock Normally, the fund invests primarily in debt securities issued or guaranteed by the U.S. government, its agencies or instrumentalities, investment grade debt securities (including convertible debt) of U.S. and non-U.S. corporate and other issuers, mortgage-related securities, including “sub-prime” mortgages, and asset-backed securities of U.S. and non-U.S. issuers and short-term money market instruments of U.S. and non-U.S. issuers. Normally, at least 80% of the fund’s net assets (plus the amount of borrowings, if any, for investment purposes) are invested in debt securities that are rated investment grade at the time of purchase or cash and cash equivalents. The fund may invest in debt securities of issuers in any industry or market sector. Derivative instruments that provide exposure to investment grade debt securities or have similar economic characteristics may be used to satisfy the fund’s 80% policy. The fund may invest up to 20% of its net assets in below investment grade debt securities (known as “junk bonds”) including securities that are in default. The fund may invest in floating rate loans, subordinated debt securities and insurance-linked securities. The fund will normally maintain a dollar-weighted average portfolio maturity of no more than 3 years. The maturity of a fixed income security is a measure of the time remaining until final payment on the security is due. The fund’s investments may have fixed or variable principal payments and all types of interest rate payment and reset terms, including fixed rate, adjustable rate, floating rate, inverse floating rate, zero coupon, contingent, deferred, payment in kind and auction rate features. The fund may invest up to 20% of its total assets in securities of non-U.S. issuers, including up to 5% of its total assets in debt securities of emerging market issuers. The fund may invest a substantial portion of its assets in asset-backed securities and mortgage-related securities, including credit risk transfer securities, and commercial mortgage-backed securities, collateralized mortgage obligations (CMOs) and other mortgage-related securities issued by private issuers. The fund's investments in mortgage-related securities may include instruments, the underlying assets of which allow for balloon payments (where a substantial portion of a mortgage loan balance is paid at maturity, which can shorten the average life of the mortgage-backed instrument) or negative amortization payments (where as a result of a payment cap, payments on a mortgage loan are less than the amount of principal and interest owed, with excess amounts added to the outstanding principal balance, which can extend the average life of the mortgage-backed instrument). The fund may, but is not required to, use derivatives such as credit default swaps and forward foreign currency transactions. The fund may use derivatives for a variety of purposes, including: in an attempt to hedge against adverse changes in the market price of securities, interest rates or currency exchange rates; as a substitute for purchasing or selling securities; to attempt to increase the fund's return as a non-hedging strategy that may be considered speculative; to manage portfolio characteristics; and as a cash flow management technique. The fund may choose not to make use of derivatives for a variety of reasons, and any use may be limited by applicable law and regulations. The adviser considers both broad economic and issuer specific factors in selecting investments. In assessing the appropriate maturity, credit quality and sector weighting of the fund's portfolio, the adviser considers a variety of factors that are expected to influence economic activity and interest rates. The adviser selects individual securities to buy and sell based upon such factors as a security’s yield, liquidity and rating, an assessment of credit quality, and sector and issuer diversification.The adviser integrates environmental, social and corporate governance (ESG) considerations into its investment research process by evaluating the business models and practices of issuers and their ESG-related risks. The adviser believes ESG analysis is a meaningful facet of fundamental research, the process of evaluating an issuer based on its financial position, business operations, competitive standing and management. This process considers ESG information, where available, in assessing an investment’s performance potential. The adviser generally considers ESG information in the context of an issuer’s respective sector or industry. The adviser may consider ESG ratings provided by third parties or internal sources, as well as issuer disclosures and public information, in evaluating issuers. ESG considerations are not a primary focus of the fund, and the weight given by the adviser to ESG considerations in making investment decisions will vary and, for any specific decision, they may be given little or no weight. Notwithstanding the foregoing, the adviser generally will not invest fund assets in companies engaged in the production, sale, storage of, or providing services for, certain controversial weapons, including chemical, biological and depleted uranium weapons and certain antipersonnel mines and cluster bombs.
Risk [Heading] rr_RiskHeading <span style="color:#000000;font-family:Arial;font-size:11pt;font-weight:bold;">Principal risks of investing in the fund</span>
Bar Chart and Performance Table [Heading] rr_BarChartAndPerformanceTableHeading <span style="color:#000000;font-family:Arial;font-size:11pt;font-weight:bold;">The fund's past performance</span>
Performance Narrative [Text Block] rr_PerformanceNarrativeTextBlock The bar chart and table indicate the risks and volatility of an investment in the fund by showing how the fund has performed in the past. The bar chart shows changes in the performance of the fund's Class A shares from calendar year to calendar year. The table shows the average annual total returns for each class of the fund over time and compares these returns to the returns of two indexes: (1) the Bloomberg U.S. Aggregate Bond Index, which may provide an indication of the performance of the overall U.S. fixed income market, and (2) the Bloomberg One- to Three-Year Government/Credit Index.You can obtain updated performance information by visiting https://www.amundi.com/usinvestors/Products/Mutual-Funds or by calling 1-800-225-6292.The fund's past performance (before and after taxes) does not necessarily indicate how it will perform in the future.The bar chart does not reflect any sales charge you may pay when you buy fund shares. If this amount was reflected, returns would be less than those shown.
Performance Information Illustrates Variability of Returns [Text] rr_PerformanceInformationIllustratesVariabilityOfReturns <span style="font-family:Times New Roman;font-size:10pt;">The bar chart and table indicate the risks and volatility of an investment in the fund by showing how the fund has performed in the past. The bar chart shows changes in the performance of the fund's Class A shares from calendar year to calendar year. </span><span style="font-family:Times New Roman;font-size:10pt;">The table shows the average annual total returns for each class of </span><span style="font-family:Times New Roman;font-size:10pt;">the fund over time and compares these returns to the returns of two indexes:</span><span style="font-family:Times New Roman;font-size:10pt;line-height:12pt;"> </span><span style="font-family:Times New Roman;font-size:10pt;">(1) the Bloomberg U.S. Aggregate Bond Index, which may provide an indication of the performance of the overall U.S. fixed income market, and (2) the Bloomberg One- to Three-Year Government/Credit Index.</span>
Performance Additional Market Index [Text] rr_PerformanceAdditionalMarketIndex <span style="font-family:Times New Roman;font-size:10pt;">The table shows the average annual total returns for each class of </span><span style="font-family:Times New Roman;font-size:10pt;">the fund over time and compares these returns to the returns of two indexes:</span><span style="font-family:Times New Roman;font-size:10pt;line-height:12pt;"> </span><span style="font-family:Times New Roman;font-size:10pt;">(1) the Bloomberg U.S. Aggregate Bond Index, which may provide an indication of the performance of the overall U.S. fixed income market, and (2) the Bloomberg One- to Three-Year Government/Credit Index.</span>
Performance Availability Phone [Text] rr_PerformanceAvailabilityPhone <span style="font-family:Times New Roman;font-size:10pt;">1-800-225-6292</span>
Performance Availability Website Address [Text] rr_PerformanceAvailabilityWebSiteAddress <span style="font-family:Times New Roman;font-size:10pt;">https://www.amundi.com/usinvestors/Products/Mutual-Funds</span>
Performance Past Does Not Indicate Future [Text] rr_PerformancePastDoesNotIndicateFuture <span style="color:#000000;font-family:Times New Roman;font-size:10pt;">The fund's past performance (before and after taxes) does not necessarily indicate how it will perform in the future.</span>
Bar Chart [Heading] rr_BarChartHeading <span style="color:#000000;font-family:Arial;font-size:9pt;font-weight:bold;">Annual return Class A shares (%) </span><span style="color:#000000;font-family:Times New Roman;font-size:10pt;">(Year ended December 31)</span>
Bar Chart Does Not Reflect Sales Loads [Text] rr_BarChartDoesNotReflectSalesLoads <span style="color:#000000;font-family:Times New Roman;font-size:10pt;">The bar chart does not reflect any sales charge you may pay when you buy fund shares. If this amount was reflected, returns would be less than those shown.</span>
Bar Chart Closing [Text Block] rr_BarChartClosingTextBlock For the period covered by the bar chart:ReturnsPeriod BeginningPeriod EndingHighest Calendar Quarter4.80%04/01/2020 to06/30/2020Lowest Calendar Quarter-7.96%01/01/2020 to03/31/2020Year-to-Date5.53%September 30, 2024
Performance Table Heading rr_PerformanceTableHeading <span style="color:#000000;font-family:Arial;font-size:9pt;font-weight:bold;">Average annual total return (%) </span><span style="font-family:Times New Roman;font-size:10pt;">(for periods ended December 31, 2023)</span>
Performance Table Uses Highest Federal Rate rr_PerformanceTableUsesHighestFederalRate <span style="font-family:Times New Roman;font-size:10pt;">After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes.</span>
Performance Table Not Relevant to Tax Deferred rr_PerformanceTableNotRelevantToTaxDeferred <span style="font-family:Times New Roman;font-size:10pt;">Actual after-tax returns depend on the investor's tax situation and may differ from those shown. The after-tax returns shown are not relevant to investors who hold fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.</span>
Performance Table One Class of after Tax Shown [Text] rr_PerformanceTableOneClassOfAfterTaxShown <span style="color:#000000;font-family:Times New Roman;font-size:10pt;">After-tax returns are shown only for Class A shares. After-tax returns for Class C, Class C2, Class K and Class Y shares will vary.</span>
Performance Table Narrative rr_PerformanceTableNarrativeTextBlock After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes.Actual after-tax returns depend on the investor's tax situation and may differ from those shown. The after-tax returns shown are not relevant to investors who hold fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.After-tax returns are shown only for Class A shares. After-tax returns for Class C, Class C2, Class K and Class Y shares will vary.
Pioneer Short Term Income Fund | Risk Lose Money [Member]  
Risk Return Abstract rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock You could lose money on your investment in the fund.
Pioneer Short Term Income Fund | Risk Not Insured Depository Institution [Member]  
Risk Return Abstract rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock An investment in the fund is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.
Pioneer Short Term Income Fund | Market Risk [Member]  
Risk Return Abstract rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock Market risk. The market prices of securities or other assets held by the fund may go up or down, sometimes rapidly or unpredictably, due to general market conditions, such as real or perceived adverse economic, political, or regulatory conditions, political instability, recessions, inflation, changes in interest or currency rates, lack of liquidity in the bond markets, the spread of infectious illness or other public health issues, weather or climate events, armed conflict, market disruptions caused by tariffs, trade disputes, sanctions or other government actions, or other factors or adverse investor sentiment. If the market prices of the fund's securities and assets fall, the value of your investment will go down. A change in financial condition or other event affecting a single issuer or market may adversely impact securities markets as a whole. In the past decade, financial markets throughout the world have experienced increased volatility, depressed valuations, decreased liquidity and heightened uncertainty. Governmental and non-governmental issuers have defaulted on, or been forced to restructure, their debts. These conditions may continue, recur, worsen or spread. Events that have contributed to these market conditions include, but are not limited to, major cybersecurity events; geopolitical events (including wars, terror attacks and economic sanctions); measures to address budget deficits; downgrading of sovereign debt; changes in oil and commodity prices; dramatic changes in currency exchange rates; global pandemics; and public sentiment. Some sectors of the economy and individual issuers have experienced or may experience particularly large losses. Periods of extreme volatility in the financial markets, reduced liquidity of many instruments, increased government debt, inflation, and disruptions to supply chains, consumer demand and employee availability, may continue for some time. Raising the ceiling on U.S. government debt has become increasingly politicized. Any failure to increase the total amount that the U.S. government is authorized to borrow could lead to a default on U.S. government obligations, with unpredictable consequences for economies and markets in the U.S. and elsewhere. Inflation and interest rates may increase. These circumstances could adversely affect the value and liquidity of the fund's investments, impair the fund's ability to satisfy redemption requests, and negatively impact the fund's performance. In addition, inflation, rising interest rates, global supply chain disruptions and other market events could adversely affect the companies or issuers in which the fund invests. Following Russia’s invasion of Ukraine, Russian securities lost all, or nearly all, their market value. Other securities or markets could be similarly affected by past or future political, geopolitical or other events or conditions. Governments and central banks, including the U.S. Federal Reserve, have taken extraordinary and unprecedented actions to support local and global economies and the financial markets. These actions have resulted in significant expansion of public debt, including in the U.S. The consequences of high public debt, including its future impact on the economy and securities markets, may not be known for some time. U.S. Federal Reserve or other U.S. or non-U.S. governmental or central bank actions, including increases or decreases in interest rates, or contrary actions by different governments, could negatively affect financial markets generally, increase market volatility and reduce the value and liquidity of securities in which the fund invests. Policy and legislative changes in the U.S. and in other countries are affecting many aspects of financial regulation, and these and other events affecting global markets, such as the United Kingdom’s exit from the European Union (or Brexit), potential trade imbalances with China or other countries or sanctions or other government actions against Russia, other nations or individuals or companies (or their countermeasures), may contribute to decreased liquidity and increased volatility in the financial markets. The impact of these changes on the markets, and the implications for market participants, may not be fully known for some time. The U.S. and other countries are periodically involved in disputes over trade and other matters, which may result in tariffs, investment restrictions and adverse impacts on affected companies and securities. For example, the U.S. has imposed tariffs and other trade barriers on Chinese exports, has restricted sales of certain categories of goods to China, and has established barriers to investments in China. Trade disputes may adversely affect the economies of the U.S. and its trading partners, as well as companies directly or indirectly affected and financial markets generally. The U.S. government has prohibited U.S. persons, such as the fund, from investing in Chinese companies designated as related to the Chinese military. These and possible future restrictions could limit the fund's opportunities for investment and require the sale of securities at a loss or make them illiquid. Moreover, the Chinese government is involved in a longstanding dispute with Taiwan that has included threats of invasion. If the political climate between the U.S. and China does not improve or continues to deteriorate, if China were to attempt unification of Taiwan by force, or if other geopolitical conflicts develop or get worse, economies, markets and individual securities may be severely affected both regionally and globally, and the value of the fund's assets may go down. Economies and financial markets throughout the world are increasingly interconnected. Economic, financial or political events, trading and tariff arrangements, armed conflict such as between Russia and Ukraine or in the Middle East, terrorism, natural disasters, infectious illness or public health issues, cybersecurity events, supply chain disruptions, sanctions against Russia, other nations or individuals or companies and possible countermeasures, and other circumstances in one country or region could have profound impacts on other countries or regions and on global economies or markets. As a result, whether or not the fund invests in securities of issuers located in or with significant exposure to the countries or regions directly affected, the value and liquidity of the fund’s investments may be negatively affected. The fund may experience a substantial or complete loss on any security or derivative position.
Pioneer Short Term Income Fund | Interest Rate Risk [Member]  
Risk Return Abstract rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock Interest rate risk. The market prices of the fund's fixed income securities may fluctuate significantly when interest rates change. The value of your investment will generally go down when interest rates rise. A rise in rates tends to have a greater impact on the prices of longer term or duration securities. For example, if interest rates increase by 1%, the value of a fund’s portfolio with a portfolio duration of ten years would be expected to decrease by 10%, all other things being equal. A general rise in interest rates could adversely affect the price and liquidity of fixed income securities and could also result in increased redemptions from the fund. The maturity of a security may be significantly longer than its effective duration. A security’s maturity and other features may be more relevant than its effective duration in determining the security’s sensitivity to other factors affecting the issuer or markets generally, such as changes in credit quality or in the yield premium that the market may establish for certain types of securities (sometimes called “credit spread”). In general, the longer its maturity the more a security may be susceptible to these factors. When the credit spread for a fixed income security goes up or “widens,” the value of the security will generally go down.Rising interest rates can lead to increased default rates, as issuers of floating rate securities find themselves faced with higher payments. Unlike fixed rate securities, floating rate securities generally will not increase in value if interest rates decline. Changes in interest rates also will affect the amount of interest income the fund earns on its floating rate investments.
Pioneer Short Term Income Fund | Credit Risk [Member]  
Risk Return Abstract rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock Credit risk. If an issuer or guarantor of a security held by the fund or a counterparty to a financial contract with the fund defaults on its obligation to pay principal and/or interest, has its credit rating downgraded or is perceived to be less creditworthy, or the credit quality or value of any underlying assets declines, the value of your investment will typically decline. Changes in actual or perceived creditworthiness may occur quickly. The fund could be delayed or hindered in its enforcement of rights against an issuer, guarantor or counterparty.
Pioneer Short Term Income Fund | Prepayment Or Call Risk [Member]  
Risk Return Abstract rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock Prepayment or call risk. Many issuers have a right to prepay their securities. If interest rates fall, an issuer may exercise this right. If this happens, the fund will not benefit from the rise in market price that normally accompanies a decline in interest rates, and will be forced to reinvest prepayment proceeds at a time when yields on securities available in the market are lower than the yield on the prepaid security. The fund also may lose any premium it paid on the security.
Pioneer Short Term Income Fund | Extension Risk [Member]  
Risk Return Abstract rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock Extension risk. During periods of rising interest rates, the average life of certain types of securities may be extended because of slower than expected principal payments. This may lock in a below market interest rate, increase the security's duration and reduce the value of the security.
Pioneer Short Term Income Fund | Liquidity Risk [Member]  
Risk Return Abstract rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock Liquidity risk. Some securities and derivatives held by the fund may be or become impossible or difficult to purchase, sell or unwind, particularly during times of market turmoil. An instrument’s liquidity may be affected by reduced trading volume, a relative lack of market makers or legal restrictions, and illiquid securities and derivatives also may be difficult to value. Markets may become illiquid quickly. Liquidity risk may be magnified in an environment of rising interest rates or widening credit spreads. During times of market turmoil, there have been, and may be, no buyers or sellers for securities in entire asset classes. If the fund is forced to sell an illiquid asset or unwind a derivative position to meet redemption requests or other cash needs, or to try to limit losses, the fund may be forced to sell at a substantial loss or may not be able to sell at all. The fund may not receive its proceeds from the sale of certain securities for an extended period (for example, several weeks or even longer). In extreme cases, this may constrain the fund’s ability to meet its obligations (including obligations to redeeming shareholders).
Pioneer Short Term Income Fund | Portfolio Selection Risk [Member]  
Risk Return Abstract rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock Portfolio selection risk. The adviser’s judgment about the quality, relative yield, relative value or market trends affecting a particular sector or region, market segment, security, industry or about interest rates or other market factors may prove to be incorrect or may not produce the desired results, or there may be imperfections, errors or limitations in the models, tools and information used by the adviser.
Pioneer Short Term Income Fund | ESG Risk [Member]  
Risk Return Abstract rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock ESG risk. The fund’s adviser may consider ESG information in its investment research process. This may mean forgoing some investment opportunities available to funds that do not consider ESG information. In considering ESG information, the adviser may use third party ESG ratings information that it believes to be reliable, but such information may not be accurate or complete, or may be biased. ESG considerations are not a primary focus of the fund, and the weight given by the adviser to ESG considerations in making investment decisions will vary and, for any specific decision, they may be given little or no weight.
Pioneer Short Term Income Fund | US Treasury Obligations Risk [Member]  
Risk Return Abstract rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock U.S. Treasury obligations risk. The market value of direct obligations of the U.S. Treasury may vary due to changes in interest rates. In addition, changes to the financial condition or credit rating of the U.S. government may cause the value of the fund’s investments in obligations issued by the U.S. Treasury to decline.
Pioneer Short Term Income Fund | US Government Agency Obligations Risk [Member]  
Risk Return Abstract rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock U.S. government agency obligations risk. The fund invests in obligations issued by agencies and instrumentalities of the U.S. government. Government-sponsored entities such as the Federal National Mortgage Association (FNMA), the Federal Home Loan Mortgage Corporation (FHLMC) and the Federal Home Loan Banks (FHLBs), although chartered or sponsored by Congress, are not funded by congressional appropriations and the debt and mortgage-backed securities issued by them are neither guaranteed nor issued by the U.S. government. The maximum potential liability of the issuers of some U.S. government obligations may greatly exceed their current resources, including any legal right to support from the U.S. government. Such debt and mortgage-backed securities are subject to the risk of default on the payment of interest and/or principal, similar to debt of private issuers. Although the U.S. government has provided financial support to FNMA and FHLMC in the past, there can be no assurance that it will support these or other government-sponsored entities in the future.
Pioneer Short Term Income Fund | Mortgage Related And Asset Backed Securities Risk [Member]  
Risk Return Abstract rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock Mortgage-related and asset-backed securities risk. The value of mortgage-related securities, including commercial mortgage-backed securities, collateralized mortgage-backed securities, credit risk transfer securities, and asset-backed securities, will be influenced by factors affecting the assets underlying such securities. As a result, during periods of declining asset value, difficult or frozen credit markets, swings in interest rates, or deteriorating economic conditions, mortgage-related and asset-backed securities may decline in value, face valuation difficulties, become more volatile and/or become illiquid. Mortgage-backed securities tend to be more sensitive to changes in interest rates than other types of debt securities. These securities are also subject to interest rate, prepayment and extension risks. Some of these securities may receive little or no collateral protection from the underlying assets and are thus subject to the risk of default. The risk of such defaults is generally higher in the case of mortgage-backed investments offered by non-governmental issuers and those that include so-called “sub-prime” mortgages. The structure of some of these securities may be complex and there may be less available information than for other types of debt securities. Upon the occurrence of certain triggering events or defaults, the fund may become the holder of underlying assets at a time when those assets may be difficult to sell or may be sold only at a loss.
Pioneer Short Term Income Fund | Risks Of Investing In Collateralized Debt Obligations [Member]  
Risk Return Abstract rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock Risks of investing in collateralized debt obligations. Investment in a collateralized debt obligation (CDO) is subject to the credit, subordination, interest rate, valuation, prepayment, extension and other risks of the obligations underlying the CDO and the tranche of the CDO in which the fund invests. CDOs are subject to liquidity risk. Synthetic CDOs are also subject to the risks of investing in derivatives, such as credit default swaps, and leverage risk.
Pioneer Short Term Income Fund | Risks Of Instruments That Allow For Balloon Payments Or Negative Amortization Payments [Member]  
Risk Return Abstract rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock Risks of instruments that allow for balloon payments or negative amortization payments. Certain debt instruments allow for balloon payments or negative amortization payments. Such instruments permit the borrower to avoid paying currently a portion of the interest accruing on the instrument. While these features make the debt instrument more affordable to the borrower in the near term, they increase the risk that the borrower will be unable to make the resulting higher payment or payments that become due at the maturity of the loan.
Pioneer Short Term Income Fund | High Yield Or Junk Bond Risk [Member]  
Risk Return Abstract rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock High yield or “junk” bond risk. Debt securities that are below investment grade, called “junk bonds,” are speculative, have a higher risk of default or are already in default, tend to be less liquid and are more difficult to value than higher grade securities. Junk bonds tend to be volatile and more susceptible to adverse events and negative sentiments. These risks are more pronounced for securities that are already in default.
Pioneer Short Term Income Fund | Risks Of Investing In Loans [Member]  
Risk Return Abstract rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock Risks of investing in loans. Floating rate loans and similar investments may be illiquid or less liquid than other investments and difficult to value. The value of collateral, if any, securing a floating rate loan can decline or may be insufficient to meet the issuer’s obligations or may be difficult to liquidate. Market quotations for these securities may be volatile and/or subject to large spreads between bid and ask prices. No active trading market may exist for many floating rate loans, and many loans are subject to restrictions on resale. Any secondary market may be subject to irregular trading activity and extended trade settlement periods. In particular, loans may take longer than seven days to settle, potentially leading to the sale proceeds of loans not being available to meet redemption requests for a substantial period of time after the sale of the loans. To the extent that sale proceeds of loans are not available, the fund may sell securities that have shorter settlement periods or may access other sources of liquidity to meet redemption requests. There is less readily available, reliable information about most senior loans than is the case for many other types of securities. The adviser’s decision not to receive material, non-public information about an issuer of a loan either held by, or considered for investment by, the fund, under normal circumstances could place it at a disadvantage, relative to other loan investors, in assessing a loan or the loan’s issuer, and adversely affect the fund’s investment performance. Loans may not be considered “securities,” and purchasers, such as the fund, therefore may not be entitled to rely on the anti-fraud protections afforded by federal securities laws.
Pioneer Short Term Income Fund | Risks Of Investing In Insurance Linked Securities [Member]  
Risk Return Abstract rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock Risks of investing in insurance-linked securities. The fund could lose a portion or all of the principal it has invested in an insurance-linked security, and the right to additional interest and/or dividend payments with respect to the security, upon the occurrence of one or more trigger events, as defined within the terms of an insurance-linked security. Trigger events may include natural or other perils of a specific size or magnitude that occur in a designated geographic region during a specified time period, and/or that involve losses or other metrics that exceed a specific amount. The fund may also invest in insurance-linked securities that are subject to “indemnity triggers.” An indemnity trigger is a trigger based on the actual losses of the ceding sponsor (i.e., the party seeking reinsurance). Insurance-linked securities subject to indemnity triggers are often regarded as being subject to potential moral hazard, since such insurance-linked securities are triggered by actual losses of the ceding sponsor and the ceding sponsor may have an incentive to take actions and/or risks that would have an adverse effect on the fund. There is no way to accurately predict whether a trigger event will occur and, accordingly, insurance-linked securities carry significant risk. In addition to the specified trigger events, insurance-linked securities may expose the fund to other risks, including but not limited to issuer (credit) default, adverse regulatory or jurisdictional interpretations and adverse tax consequences. Certain insurance-linked securities may have limited liquidity, or may be illiquid. The fund has limited transparency into the individual contracts underlying certain insurance-linked securities, which may make the risk assessment of such securities more difficult. Certain insurance-linked securities may be difficult to value.
Pioneer Short Term Income Fund | Risks Of Subordinated Securities [Member]  
Risk Return Abstract rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock Risks of subordinated securities. A holder of securities that are subordinated or “junior” to more senior securities of an issuer is entitled to payment after holders of more senior securities of the issuer. Subordinated securities are more likely to suffer a credit loss than non-subordinated securities of the same issuer, any loss incurred by the subordinated securities is likely to be proportionately greater, and any recovery of interest or principal may take more time. As a result, even a perceived decline in creditworthiness of the issuer is likely to have a greater impact on subordinated securities than more senior securities.
Pioneer Short Term Income Fund | Risks Of Zero Coupon Bonds Payment In Kind Deferred And Contingent Payment Securities [Member]  
Risk Return Abstract rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock Risks of zero coupon bonds, payment in kind, deferred and contingent payment securities. These securities may be more speculative and may fluctuate more in value than securities which pay income periodically and in cash. In addition, although the fund receives no periodic cash payments on such securities, the fund is deemed for tax purposes to receive income from such securities, which applicable tax rules require the fund to distribute to shareholders. Such distributions may be taxable when distributed to shareholders.
Pioneer Short Term Income Fund | Risks Of Non US Investments [Member]  
Risk Return Abstract rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock Risks of non-U.S. investments. Investing in non-U.S. issuers, or in U.S. issuers that have significant exposure to foreign markets, may involve unique risks compared to investing in securities of U.S. issuers. These risks are more pronounced for issuers in emerging markets or to the extent that the fund invests significantly in one region or country. These risks may include different financial reporting practices and regulatory standards, less liquid trading markets, extreme price volatility, currency risks, changes in economic, political, regulatory and social conditions, military conflicts and sanctions, terrorism, sustained economic downturns, financial instability, reduction of government or central bank support, inadequate accounting standards, auditing and financial recordkeeping requirements, tariffs, tax disputes or other tax burdens, nationalization or expropriation of assets, arbitrary application of laws and regulations or lack of rule of law, and investment and repatriation restrictions. Investors in foreign countries often have limited rights and few practical remedies to pursue shareholder claims. Lack of information and less market regulation also may affect the value of these securities. Withholding and other non-U.S. taxes may decrease the fund’s return. Non-U.S. issuers may be located in parts of the world that have historically been prone to natural disasters. Emerging market economies tend to be less diversified than those of more developed countries. They typically have fewer medical and economic resources than more developed countries and thus they may be less able to control or mitigate the effects of a pandemic. Investing in depositary receipts is subject to many of the same risks as investing directly in non-U.S. issuers. Depositary receipts may involve higher expenses and may trade at a discount (or premium) to the underlying security. A number of countries in the European Union (EU) have experienced, and may continue to experience, severe economic and financial difficulties. In addition, the United Kingdom has withdrawn from the EU (commonly known as “Brexit”). The range and potential implications of possible political, regulatory, economic, and market outcomes of Brexit cannot be fully known but could be significant, potentially resulting in increased volatility, illiquidity and potentially lower economic growth in the affected markets, which will adversely affect the fund's investments. If one or more stockholders of a supranational entity such as the World Bank fail to make necessary additional capital contributions, the entity may be unable to pay interest or repay principal on its debt securities. Sanctions or other government actions against certain countries could negatively impact the fund’s investments in securities that have exposure to those countries. Circumstances that impact one country could have profound impacts on other countries and on global economies or markets. China and other developing market countries may be subject to considerable degrees of economic, political and social instability. The U.S. government has imposed restrictions on U.S. investor participation in certain Chinese investments. These matters could adversely affect China’s economy. In addition, China's long-running conflict over Taiwan's sovereignty, border disputes with many neighbors and historically strained relations with other Asian countries could result in military conflict that could adversely impact the economies of China and other Asian countries, disrupt supply chains, and severely affect global economies and markets. Russia launched a large-scale invasion of Ukraine on February 24, 2022. In response to the military action by Russia, various countries, including the U.S., the United Kingdom, and European Union, issued broad-ranging economic sanctions against Russia and Belarus and certain companies and individuals. Russia has taken retaliatory actions, including preventing repatriation of capital by U.S. and other investors. Since then, Russian securities lost all, or nearly all, their market value, and many other issuers, securities and markets have been adversely affected. The ongoing conflict has resulted in significant market disruptions, including in certain markets, industries and sectors, such as the oil and natural gas markets, and negatively affected global supply chains, food supplies, inflation and global growth. The U.S. and other countries may impose sanctions on other countries, companies and individuals in light of Russia’s military invasion. The extent and duration of the military action or future escalation of such hostilities, the extent and impact of existing and future sanctions, market disruptions and volatility, and the result of any diplomatic negotiations cannot be predicted. These and any related events could have a significant impact on the value and liquidity of certain fund investments, on fund performance and the value of an investment in the fund.
Pioneer Short Term Income Fund | Currency risk [Member]  
Risk Return Abstract rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock Currency risk. The fund could experience losses based on changes in the exchange rate between non-U.S. currencies and the U.S. dollar or as a result of currency conversion costs. Currency exchange rates can be volatile, and are affected by factors such as general economic conditions, the actions of the U.S. and foreign governments or central banks, the imposition of currency controls and speculation.
Pioneer Short Term Income Fund | Risks Of Convertible Securities [Member]  
Risk Return Abstract rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock Risks of convertible securities. The market values of convertible securities tend to decline as interest rates increase and, conversely, to increase as interest rates decline. A downturn in equity markets may cause the price of convertible securities to decrease relative to other fixed income securities.
Pioneer Short Term Income Fund | Derivatives Risk [Member]  
Risk Return Abstract rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock Derivatives risk. Using swaps and other derivatives can increase fund losses and reduce opportunities for gains when market prices, interest rates, currencies or the derivative instruments themselves behave in a way not anticipated by the fund. Using derivatives may increase the volatility of the fund's net asset value and may not provide the result intended. Derivatives may have a leveraging effect on the fund. Some derivatives have the potential for unlimited loss, regardless of the size of the fund’s initial investment. Derivatives are generally subject to the risks applicable to the assets, rates, indices or other indicators underlying the derivative. Changes in a derivative’s value may not correlate well with the referenced asset or metric. The fund also may have to sell assets at inopportune times to satisfy its obligations. Derivatives may be difficult to sell, unwind or value, and the counterparty may default on its obligations to the fund. Use of derivatives may have different tax consequences for the fund than an investment in the underlying security, and such differences may affect the amount, timing and character of income distributed to shareholders. The U.S. government and foreign governments have adopted and implemented or are in the process of adopting and implementing regulations governing derivatives markets, including mandatory clearing of certain derivatives, margin and reporting requirements. The ultimate impact of the regulations remains unclear. Additional regulation of derivatives may make them more costly, limit their availability or utility, otherwise adversely affect their performance or disrupt markets.
Pioneer Short Term Income Fund | Credit Default Swap Risk [Member]  
Risk Return Abstract rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock Credit default swap risk. Credit default swap contracts, a type of derivative instrument, involve special risks and may result in losses to the fund. Credit default swaps may in some cases be illiquid, and they increase credit risk since the fund has exposure to the issuer of the referenced obligation and either the counterparty to the credit default swap or, if it is a cleared transaction, the brokerage firm through which the trade was cleared and the clearing organization that is the counterparty to that trade.
Pioneer Short Term Income Fund | Structured Securities Risk [Member]  
Risk Return Abstract rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock Structured securities risk. Structured securities may behave in ways not anticipated by the fund, or they may not receive the tax, accounting or regulatory treatment anticipated by the fund.
Pioneer Short Term Income Fund | Risks Of Investing In Inverse Floating Rate Obligations [Member]  
Risk Return Abstract rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock Risks of investing in inverse floating rate obligations. The interest rate on inverse floating rate obligations will generally decrease as short-term interest rates increase, and increase as short-term rates decrease. Due to their leveraged structure, the sensitivity of the market value of an inverse floating rate obligation to changes in interest rates is generally greater than a comparable long-term bond issued by the same issuer and with similar credit quality, redemption and maturity provisions. Inverse floating rate obligations may be volatile and involve leverage risk.
Pioneer Short Term Income Fund | Forward foreign currency transactions risk [Member]  
Risk Return Abstract rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock Forward foreign currency transactions risk. The fund may not fully benefit from or may lose money on forward foreign currency transactions if changes in currency rates do not occur as anticipated or do not correspond accurately to changes in the value of the fund's holdings, or if the counterparty defaults. Such transactions may also prevent the fund from realizing profits on favorable movements in exchange rates. Risk of counterparty default is greater for counterparties located in emerging markets.
Pioneer Short Term Income Fund | Leveraging Risk [Member]  
Risk Return Abstract rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock Leveraging risk. The value of your investment may be more volatile and other risks tend to be compounded if the fund borrows or uses derivatives or other investments, such as ETFs, that have embedded leverage. Leverage generally magnifies the effect of any increase or decrease in the value of the fund's underlying assets and creates a risk of loss of value on a larger pool of assets than the fund would otherwise have, potentially resulting in the loss of all assets. Engaging in such transactions may cause the fund to liquidate positions when it may not be advantageous to do so to satisfy its obligations. New derivatives regulations require the fund, to the extent it uses derivatives to a material extent, to, among other things, comply with certain overall limits on leverage. These regulations may limit the ability of the fund to pursue its investment strategies and may not be effective to mitigate the fund's risk of loss from derivatives.
Pioneer Short Term Income Fund | Market Segment Risk [Member]  
Risk Return Abstract rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock Market segment risk. To the extent the fund emphasizes, from time to time, investments in a market segment, the fund will be subject to a greater degree to the risks particular to that segment, and may experience greater market fluctuation than a fund without the same focus.
Pioneer Short Term Income Fund | Valuation Risk [Member]  
Risk Return Abstract rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock Valuation risk. Nearly all of the fund's investments are valued using a fair value methodology. The sales price the fund could receive for any particular portfolio investment may differ from the fund’s valuation of the investment, particularly for illiquid securities and securities that trade in thin or volatile markets. These differences may increase significantly and affect fund investments more broadly during periods of market volatility. Investors who purchase or redeem fund shares may receive fewer or more shares or lower or higher redemption proceeds than they would have received if the securities had not been fair-valued or if a different valuation methodology had been used. The ability to value the fund’s investments may also be impacted by technological issues and/or errors by pricing services or other third party service providers.
Pioneer Short Term Income Fund | Redemption risk [Member]  
Risk Return Abstract rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock Redemption risk. The fund may experience heavy redemptions that could cause the fund to liquidate its assets at inopportune times or at a loss or depressed value, or accelerate taxable gains or transaction costs, which could cause the value of your investment to decline.
Pioneer Short Term Income Fund | Cybersecurity Risk [Member]  
Risk Return Abstract rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock Cybersecurity risk. Cybersecurity failures by and breaches of the fund’s adviser, transfer agent, distributor, custodian, fund accounting agent or other service providers may disrupt fund operations, interfere with the fund’s ability to calculate its NAV, prevent fund shareholders from purchasing, redeeming or exchanging shares or receiving distributions or receiving timely information regarding the fund or their investment in the fund, cause loss of or unauthorized access to private shareholder information, and result in financial losses to the fund and its shareholders, regulatory fines, penalties, reputational damage, or additional compliance costs. New ways to carry out cyber attacks continue to develop. Therefore, there is a chance that some risks have not been identified or prepared for, or that an attack may not be detected, which puts limitations on the fund's ability to plan for or respond to a cyber attack.
Pioneer Short Term Income Fund | Expense Risk [Member]  
Risk Return Abstract rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock Expense risk. Your actual costs of investing in the fund may be higher than the expenses shown in “Annual fund operating expenses” for a variety of reasons. For example, expense ratios may be higher than those shown if overall net assets decrease. Net assets are more likely to decrease and fund expense ratios are more likely to increase when markets are volatile.
Pioneer Short Term Income Fund | A  
Risk Return Abstract rr_RiskReturnAbstract  
Maximum sales charge (load) when you buy shares (as a percentage of offering price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice none
Maximum deferred sales charge (load) (as a percentage of offering price or the amount you receive when you sell shares, whichever is less) rr_MaximumDeferredSalesChargeOverOther none
Management Fees rr_ManagementFeesOverAssets 0.35%
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 0.20%
Other Expenses rr_OtherExpensesOverAssets 0.38%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 0.93%
Less: Fee Waiver and Expense Reimbursement rr_FeeWaiverOrReimbursementOverAssets 0.10% [1]
Net Expenses rr_NetExpensesOverAssets 0.83% [1]
1 rr_ExpenseExampleYear01 $ 85
3 rr_ExpenseExampleYear03 286
5 rr_ExpenseExampleYear05 505
10 rr_ExpenseExampleYear10 1,134
1 rr_ExpenseExampleNoRedemptionYear01 85
3 rr_ExpenseExampleNoRedemptionYear03 286
5 rr_ExpenseExampleNoRedemptionYear05 505
10 rr_ExpenseExampleNoRedemptionYear10 $ 1,134
2014 rr_AnnualReturn2014 1.04%
2015 rr_AnnualReturn2015 0.67%
2016 rr_AnnualReturn2016 1.74%
2017 rr_AnnualReturn2017 1.39%
2018 rr_AnnualReturn2018 1.40%
2019 rr_AnnualReturn2019 4.49%
2020 rr_AnnualReturn2020 0.99%
2021 rr_AnnualReturn2021 1.58%
2022 rr_AnnualReturn2022 (3.80%)
2023 rr_AnnualReturn2023 6.87%
Year to Date Return, Label rr_YearToDateReturnLabel <span style="font-family:Arial Narrow;font-size:8pt;margin-left:0.0pt;">Year-to-Date</span>
Bar Chart, Year to Date Return, Date rr_BarChartYearToDateReturnDate Sep. 30, 2024
Bar Chart, Year to Date Return rr_BarChartYearToDateReturn 5.53%
Highest Quarterly Return, Label rr_HighestQuarterlyReturnLabel <span style="font-family:Arial Narrow;font-size:8pt;margin-left:0.0pt;">Highest Calendar Quarter</span>
Highest Quarterly Return, Date rr_BarChartHighestQuarterlyReturnDate Jun. 30, 2020
Highest Quarterly Return rr_BarChartHighestQuarterlyReturn 4.80%
Lowest Quarterly Return, Label rr_LowestQuarterlyReturnLabel <span style="font-family:Arial Narrow;font-size:8pt;margin-left:0.0pt;">Lowest Calendar Quarter</span>
Lowest Quarterly Return, Date rr_BarChartLowestQuarterlyReturnDate Mar. 31, 2020
Lowest Quarterly Return rr_BarChartLowestQuarterlyReturn (7.96%)
1 Year rr_AverageAnnualReturnYear01 6.87%
5 Years rr_AverageAnnualReturnYear05 1.97%
10 Years rr_AverageAnnualReturnYear10 1.61%
SinceInception rr_AverageAnnualReturnSinceInception 2.37%
InceptionDate rr_AverageAnnualReturnInceptionDate Jul. 08, 2004
Pioneer Short Term Income Fund | C  
Risk Return Abstract rr_RiskReturnAbstract  
Maximum sales charge (load) when you buy shares (as a percentage of offering price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice none
Maximum deferred sales charge (load) (as a percentage of offering price or the amount you receive when you sell shares, whichever is less) rr_MaximumDeferredSalesChargeOverOther none
Management Fees rr_ManagementFeesOverAssets 0.35%
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 0.50%
Other Expenses rr_OtherExpensesOverAssets 0.18%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 1.03%
Less: Fee Waiver and Expense Reimbursement rr_FeeWaiverOrReimbursementOverAssets none [1]
Net Expenses rr_NetExpensesOverAssets 1.03% [1]
1 rr_ExpenseExampleYear01 $ 105
3 rr_ExpenseExampleYear03 328
5 rr_ExpenseExampleYear05 569
10 rr_ExpenseExampleYear10 1,259
1 rr_ExpenseExampleNoRedemptionYear01 105
3 rr_ExpenseExampleNoRedemptionYear03 328
5 rr_ExpenseExampleNoRedemptionYear05 569
10 rr_ExpenseExampleNoRedemptionYear10 $ 1,259
1 Year rr_AverageAnnualReturnYear01 6.70%
5 Years rr_AverageAnnualReturnYear05 1.82%
10 Years rr_AverageAnnualReturnYear10 1.42%
SinceInception rr_AverageAnnualReturnSinceInception 1.89%
InceptionDate rr_AverageAnnualReturnInceptionDate Jul. 08, 2004
Pioneer Short Term Income Fund | C2  
Risk Return Abstract rr_RiskReturnAbstract  
Maximum sales charge (load) when you buy shares (as a percentage of offering price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice none
Maximum deferred sales charge (load) (as a percentage of offering price or the amount you receive when you sell shares, whichever is less) rr_MaximumDeferredSalesChargeOverOther 1.00%
Management Fees rr_ManagementFeesOverAssets 0.35%
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 0.50%
Other Expenses rr_OtherExpensesOverAssets 0.14%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 0.99%
Less: Fee Waiver and Expense Reimbursement rr_FeeWaiverOrReimbursementOverAssets none [1]
Net Expenses rr_NetExpensesOverAssets 0.99% [1]
1 rr_ExpenseExampleYear01 $ 201
3 rr_ExpenseExampleYear03 315
5 rr_ExpenseExampleYear05 547
10 rr_ExpenseExampleYear10 1,213
1 rr_ExpenseExampleNoRedemptionYear01 101
3 rr_ExpenseExampleNoRedemptionYear03 315
5 rr_ExpenseExampleNoRedemptionYear05 547
10 rr_ExpenseExampleNoRedemptionYear10 $ 1,213
1 Year rr_AverageAnnualReturnYear01 5.59%
5 Years rr_AverageAnnualReturnYear05 1.84%
10 Years rr_AverageAnnualReturnYear10 1.44%
SinceInception rr_AverageAnnualReturnSinceInception 1.44%
InceptionDate rr_AverageAnnualReturnInceptionDate Aug. 01, 2013
Pioneer Short Term Income Fund | K  
Risk Return Abstract rr_RiskReturnAbstract  
Maximum sales charge (load) when you buy shares (as a percentage of offering price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice none
Maximum deferred sales charge (load) (as a percentage of offering price or the amount you receive when you sell shares, whichever is less) rr_MaximumDeferredSalesChargeOverOther none
Management Fees rr_ManagementFeesOverAssets 0.35%
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Other Expenses rr_OtherExpensesOverAssets 0.11%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 0.46%
Less: Fee Waiver and Expense Reimbursement rr_FeeWaiverOrReimbursementOverAssets none [1]
Net Expenses rr_NetExpensesOverAssets 0.46% [1]
1 rr_ExpenseExampleYear01 $ 47
3 rr_ExpenseExampleYear03 148
5 rr_ExpenseExampleYear05 258
10 rr_ExpenseExampleYear10 579
1 rr_ExpenseExampleNoRedemptionYear01 47
3 rr_ExpenseExampleNoRedemptionYear03 148
5 rr_ExpenseExampleNoRedemptionYear05 258
10 rr_ExpenseExampleNoRedemptionYear10 $ 579
1 Year rr_AverageAnnualReturnYear01 7.26%
5 Years rr_AverageAnnualReturnYear05 2.40%
10 Years rr_AverageAnnualReturnYear10
SinceInception rr_AverageAnnualReturnSinceInception 2.05%
InceptionDate rr_AverageAnnualReturnInceptionDate Dec. 01, 2014
Pioneer Short Term Income Fund | Y  
Risk Return Abstract rr_RiskReturnAbstract  
Maximum sales charge (load) when you buy shares (as a percentage of offering price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice none
Maximum deferred sales charge (load) (as a percentage of offering price or the amount you receive when you sell shares, whichever is less) rr_MaximumDeferredSalesChargeOverOther none
Management Fees rr_ManagementFeesOverAssets 0.35%
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Other Expenses rr_OtherExpensesOverAssets 0.20%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 0.55%
Less: Fee Waiver and Expense Reimbursement rr_FeeWaiverOrReimbursementOverAssets 0.09% [1]
Net Expenses rr_NetExpensesOverAssets 0.46% [1]
1 rr_ExpenseExampleYear01 $ 47
3 rr_ExpenseExampleYear03 167
5 rr_ExpenseExampleYear05 298
10 rr_ExpenseExampleYear10 681
1 rr_ExpenseExampleNoRedemptionYear01 47
3 rr_ExpenseExampleNoRedemptionYear03 167
5 rr_ExpenseExampleNoRedemptionYear05 298
10 rr_ExpenseExampleNoRedemptionYear10 $ 681
1 Year rr_AverageAnnualReturnYear01 7.26%
5 Years rr_AverageAnnualReturnYear05 2.37%
10 Years rr_AverageAnnualReturnYear10 1.93%
SinceInception rr_AverageAnnualReturnSinceInception 2.70%
InceptionDate rr_AverageAnnualReturnInceptionDate Jul. 08, 2004
Pioneer Short Term Income Fund | Return After Taxes on Distributions | A  
Risk Return Abstract rr_RiskReturnAbstract  
1 Year rr_AverageAnnualReturnYear01 4.65%
5 Years rr_AverageAnnualReturnYear05 0.66%
10 Years rr_AverageAnnualReturnYear10 0.55%
SinceInception rr_AverageAnnualReturnSinceInception 1.21%
Pioneer Short Term Income Fund | Return After Taxes on Distributions and Sale of Fund Shares | A  
Risk Return Abstract rr_RiskReturnAbstract  
1 Year rr_AverageAnnualReturnYear01 4.02%
5 Years rr_AverageAnnualReturnYear05 0.94%
10 Years rr_AverageAnnualReturnYear10 0.76%
SinceInception rr_AverageAnnualReturnSinceInception 1.35%
Pioneer Short Term Income Fund | Bloomberg U.S. Aggregate Bond Index (reflects no deduction for fees, expenses or taxes)  
Risk Return Abstract rr_RiskReturnAbstract  
1 Year rr_AverageAnnualReturnYear01 5.53%
5 Years rr_AverageAnnualReturnYear05 1.10%
10 Years rr_AverageAnnualReturnYear10 1.81%
SinceInception rr_AverageAnnualReturnSinceInception 3.21%
InceptionDate rr_AverageAnnualReturnInceptionDate Jul. 08, 2004
Pioneer Short Term Income Fund | Bloomberg One- to Three-Year Government/Credit Index (reflects no deduction for fees, expenses or taxes)  
Risk Return Abstract rr_RiskReturnAbstract  
1 Year rr_AverageAnnualReturnYear01 4.61%
5 Years rr_AverageAnnualReturnYear05 1.51%
10 Years rr_AverageAnnualReturnYear10 1.27%
SinceInception rr_AverageAnnualReturnSinceInception 2.12%
InceptionDate rr_AverageAnnualReturnInceptionDate Jul. 08, 2004
[1] The fund’s investment adviser has contractually agreed to limit ordinary operating expenses (ordinary operating expenses means all fund expenses other than taxes, brokerage commissions, acquired fund fees and expenses, and extraordinary expenses, such as litigation) to the extent required to reduce fund expenses to 0.83% and 0.46% of the average daily net assets attributable to Class A and Class Y shares, respectively. These expense limitations are in effect through January 1, 2026. There can be no assurance that the adviser will extend the expense limitations beyond such time. Net expenses for a class may exceed the applicable expense limitation to the extent that the fund incurs excluded expenses. While in effect, the arrangement may be terminated for a class only by agreement of the adviser and the Board of Trustees.