Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	Pioneer Series Trust V
Prospectus Date	rr_ProspectusDate	Dec. 31, 2018
Pioneer High Income Municipal Fund
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	PIONEER HIGH INCOME MUNICIPAL FUND
Objective [Heading]	rr_ObjectiveHeading	INVESTMENT OBJECTIVE
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	Maximize total return through a combination of income that is exempt from regular federal income tax and capital appreciation.
Expense [Heading]	rr_ExpenseHeading	FEES AND EXPENSES OF THE FUND
Expense Narrative [Text Block]	rr_ExpenseNarrativeTextBlock	This table describes the fees and expenses that you may pay if you buy and hold shares of the fund. You may qualify for sales charge discounts if you or your family invest, or agree to invest in the future, at least $100,000 in Class A shares of the Pioneer funds. More information about these and other discounts is available from your investment professional and in the "Sales charges" section of the prospectus beginning on page 52, the "Intermediary defined sales charge waiver policies" section of the prospectus beginning on page 90, and the "Sales charges" section of the statement of additional information beginning on page 54. 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	SHAREOWNER FEES<br/>(fees paid directly from your investment)
Operating Expenses Caption [Text]	rr_OperatingExpensesCaption	ANNUAL FUND OPERATING EXPENSES<br/>(expenses that you pay each year as a percentage of<br/>the value of your investment)
Fee Waiver or Reimbursement over Assets, Date of Termination	rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination	December 31, 2019
Portfolio Turnover [Heading]	rr_PortfolioTurnoverHeading	PORTFOLIO TURNOVER
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 22% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	22.00%
Expenses Deferred Charges [Text Block]	rr_ExpensesDeferredChargesTextBlock	Class A purchases of $500,000 or more that are not subject to an initial sales charge may be subject to a contingent deferred sales charge of 1%. See "Sales charges."
Expense Breakpoint Discounts [Text]	rr_ExpenseBreakpointDiscounts	You may qualify for sales charge discounts if you or your family invest, or agree to invest in the future, at least $100,000 in Class A shares of the Pioneer funds.
Expense Breakpoint, Minimum Investment Required [Amount]	rr_ExpenseBreakpointMinimumInvestmentRequiredAmount	$ 100,000
Other Expenses, New Fund, Based on Estimates [Text]	rr_OtherExpensesNewFundBasedOnEstimates	Other expenses for Class K shares are estimated for the current year.
Expense Example [Heading]	rr_ExpenseExampleHeading	EXAMPLE
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. 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	IF YOU REDEEM YOUR SHARES<br/>NUMBER OF YEARS YOU OWN YOUR SHARES
Expense Example, No Redemption, By Year, Caption [Text]	rr_ExpenseExampleNoRedemptionByYearCaption	IF YOU DO NOT REDEEM YOUR SHARES<br/>NUMBER OF YEARS YOU OWN YOUR SHARES
Strategy [Heading]	rr_StrategyHeading	PRINCIPAL INVESTMENT STRATEGIES
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	Normally, the fund invests at least 80% of its net assets (plus the amount of borrowings, if any, for investment purposes) in debt securities and other obligations issued by or on behalf of states, counties, municipalities, territories and possessions of the United States and the District of Columbia and their authorities, political subdivisions, agencies and instrumentalities, the interest on which is exempt from regular federal income tax ("municipal securities"). Derivative instruments that provide exposure to municipal securities or have similar economic characteristics may be used to satisfy the fund's 80% policy. Municipal securities are generally issued to finance public works such as airports, bridges, highways, housing, hospitals, mass transportation projects, schools and water and sewer works. Municipal securities may be issued to repay outstanding obligations, to raise funds for general operating expenses, or to make loans to other institutions and facilities. They also may be issued by or on behalf of, public authorities to finance various privately operated facilities which are expected to benefit the municipality and its residents, such as business, manufacturing, housing, sports and pollution control, as well as public facilities such as airports, mass transit systems, ports and parking. The fund may invest in municipal securities with a broad range of maturities. Municipal securities with longer maturities are generally more volatile than other fixed income securities with shorter maturities. The fund may invest 25% or more of its assets in issuers in any one or more states or in the same economic sector or similar project type. The fund primarily invests in "high yield" municipal obligations, commonly referred to as "junk bonds." For this purpose, "high yield" municipal obligations are municipal obligations rated at the time of purchase Ba or lower by Moody's Investors Service, Inc. or BB or lower by Standard and Poor's Ratings Group or unrated securities determined by the adviser to be of comparable credit quality. The fund may invest in securities in any rating category, including those in default, and in debtor-in-possession financings. Interest income from certain types of municipal obligations in which the fund may invest generally will be subject to the federal alternative minimum tax (the "AMT"). The fund may not be suitable for investors subject to the AMT. The rate of interest paid on municipal securities normally is lower than the rate of interest paid on taxable securities. The fund's investments may have fixed or variable principal payments and all types of interest rate payment and reset terms, including fixed and floating rates, inverse floating rate, zero coupon, contingent, deferred and payment in kind and auction rate features. The fund's investments may include instruments that allow for balloon payments or negative amortization payments. The fund may, but is not required to, use derivatives, such as synthetic municipal securities, inverse floating rate obligations and credit default swaps. 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 fund also may invest in subordinated securities and asset-backed securities, including collateralized debt obligations, and may hold cash or other short-term investments. The fund may invest up to 20% of its net assets in inverse floating rate obligations. The fund may invest up to 20% of its net assets in taxable investments, including securities of other investment companies, commercial paper, U.S. government securities, U.S. or foreign bank instruments and repurchase agreements. The adviser considers both broad economic factors and issuer specific factors in selecting investments. In assessing the appropriate maturity and rating 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 issuer diversification.
Risk [Heading]	rr_RiskHeading	PRINCIPAL RISKS OF INVESTING IN THE FUND
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	You could lose money on your investment in the fund. As with any mutual fund, there is no guarantee that the fund will achieve its objective. MARKET RISK. The market prices of securities 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, inflation, changes in interest or currency rates, lack of liquidity in the bond markets or adverse investor sentiment. 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 and terror attacks); measures to address budget deficits; downgrading of sovereign debt; changes in oil and commodity prices; dramatic changes in currency exchange rates; and public sentiment. U.S. and non-U.S. governments and central banks have provided significant support to financial markets, including by keeping interest rates at historically low levels. The U.S. Federal Reserve is reducing its market support activities and has begun raising interest rates. Certain foreign governments and central banks have implemented or may implement so-called negative interest rates (e.g., charging depositors who keep their cash at a bank) to spur economic growth. Further Federal Reserve or other U.S. or non-U.S. governmental or central bank actions, including interest rate increases 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 and other events affecting global markets, such as the United Kingdom's expected exit from the European Union (or Brexit), are affecting many aspects of financial regulation, and may in some instances contribute to decreased liquidity and increased volatility in the financial markets. The impact of these changes on the markets, and the practical implications for market participants, may not be fully known for some time. Economies and financial markets throughout the world are increasingly interconnected. Economic, financial or political events, trading and tariff arrangements, terrorism, natural disasters and other circumstances in one country or region could have profound impacts 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 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 individual security or derivative position. INTEREST RATE RISK. Interest rates may go up, causing the value of the fund's investments to decline (this risk generally will be greater for securities with longer maturities or durations). 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. Interest rates in the U.S. have been historically low and have begun to rise, and the fund faces a heightened risk that interest rates may continue to rise. 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. 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. 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. 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. LIQUIDITY RISK. Some securities and derivatives held by the fund may be 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. Liquidity risk may be magnified in a rising interest rate environment. If the fund is forced to sell an illiquid asset or unwind a derivative position to meet redemption requests or other cash needs, the fund may be forced to sell at a loss. 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). 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. 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 or about interest rates generally may prove to be incorrect. MUNICIPAL SECURITIES RISK. The municipal bond market can be susceptible to unusual volatility, particularly for lower-rated and unrated securities. Liquidity can be reduced unpredictably in response to overall economic conditions or credit tightening. Municipal issuers may be adversely affected by rising health care costs, increasing unfunded pension liabilities, and by the phasing out of federal programs providing financial support. Unfavorable conditions and developments relating to projects financed with municipal securities can result in lower revenues to issuers of municipal securities, potentially resulting in defaults. Issuers often depend on revenues from these projects to make principal and interest payments. The value of municipal securities can also be adversely affected by changes in the financial condition of one or more individual municipal issuers or insurers of municipal issuers, regulatory and political developments, tax law changes or other legislative actions, and by uncertainties and public perceptions concerning these and other factors. Municipal securities may be more susceptible to downgrades or defaults during recessions or similar periods of economic stress. In recent periods, an increasing number of municipal issuers in the United States have defaulted on obligations and commenced insolvency proceedings. Financial difficulties of municipal issuers may continue or get worse. To the extent the fund invests significantly in a single state, or in securities the payments on which are dependent upon a single project or source of revenues, or that relate to a sector or industry, including health care facilities, education, special revenues and pollution control, the fund will be more susceptible to associated risks and developments. TAXABLE INVESTMENT RISK. Although distributions of interest income from the fund's tax-exempt securities are generally exempt from regular federal income tax, distributions from other sources, including capital gain distributions, and any gains on the sale of your shares are not. In addition, the interest on the fund's municipal securities could become subject to regular federal income tax or the AMT due to noncompliant conduct by issuers, unfavorable legislation or litigation, or adverse interpretations by regulatory authorities. You should consult a tax adviser about whether the AMT applies to you and about state and local taxes on your fund distributions. ASSET-BACKED SECURITIES RISK. The value of 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, asset-backed securities may decline in value, face valuation difficulties, become more volatile and/or become illiquid. These securities are also subject to prepayment and call risk. 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 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. 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. 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. 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. 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. 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. 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 FNMA, FHLMC and the 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. DERIVATIVES RISK. Using synthetic municipal securities, inverse floating rate obligations, credit default swaps and other derivatives can increase fund losses and reduce opportunities for gains when market prices, interest rates 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. 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 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. SYNTHETIC MUNICIPAL SECURITIES RISK. The tax-exempt character of the interest paid on tender option bonds, bond receipts and similar synthetic municipal securities, a type of derivative instrument, is based on the tax-exempt income stream from the collateral. In addition to the risks of investing in municipal securities and in derivatives generally, investments in synthetic municipal securities are subject to the risk that income derived from such securities is deemed to be taxable. 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. 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. 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 or meet segregation requirements. REPURCHASE AGREEMENT RISK. In the event that the other party to a repurchase agreement defaults on its obligations, the fund may encounter delay and incur costs before being able to sell the security. Such a delay may involve loss of interest or a decline in price of the security. In addition, if the fund is characterized by a court as an unsecured creditor, it would be at risk of losing some or all of the principal and interest involved in the transaction. 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. VALUATION RISK. 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 or that are valued using a fair value methodology. Investors who purchase or redeem fund shares on days when the fund is holding fair-valued securities may receive fewer or more shares or lower or higher redemption proceeds than they would have received if the fund had not fair-valued the securities or had used a different valuation methodology. The fund's ability to value its investments may also be impacted by technological issues and/or errors by pricing services or other third party service providers. 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, which could cause the value of your investment to decline. CYBERSECURITY RISK. Cybersecurity failures by and breaches of the fund's adviser, transfer agent, distributor, custodian, fund accounting agent and 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, cause loss of or unauthorized access to private shareholder information, and result in financial losses, regulatory fines, penalties, reputational damage, or additional compliance costs. 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. Please note that there are many other factors that could adversely affect your investment and that could prevent the fund from achieving its goals. 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.
Risk Lose Money [Text]	rr_RiskLoseMoney	You could lose money on your investment in the fund.
Risk Not Insured Depository Institution [Text]	rr_RiskNotInsuredDepositoryInstitution	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.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	THE FUND'S PAST PERFORMANCE
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 the Bloomberg Barclays U.S. Municipal High Yield Bond Index, a broad-based measure of market performance that has characteristics relevant to the fund's investment strategies. You can obtain updated performance information by visiting https://us.amundipioneer.com/products/mutual-funds/performance.html 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	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 the Bloomberg Barclays U.S. Municipal High Yield Bond Index, a broad-based measure of market performance that has characteristics relevant to the fund's investment strategies.
Performance One Year or Less [Text]	rr_PerformanceOneYearOrLess	No performance information is presented for Class K shares in the table because Class K shares do not have annual returns for at least one calendar year.
Performance Additional Market Index [Text]	rr_PerformanceAdditionalMarketIndex	The table shows the average annual total returns for each class of the fund over time and compares these returns to the returns of the Bloomberg Barclays U.S. Municipal High Yield Bond Index, a broad-based measure of market performance that has characteristics relevant to the fund's investment strategies.
Performance Availability Phone [Text]	rr_PerformanceAvailabilityPhone	1-800-225-6292
Performance Availability Website Address [Text]	rr_PerformanceAvailabilityWebSiteAddress	https://us.amundipioneer.com/products/mutual-funds/performance.html
Performance Past Does Not Indicate Future [Text]	rr_PerformancePastDoesNotIndicateFuture	The fund's past performance (before and after taxes) does not necessarily indicate how it will perform in the future.
Bar Chart [Heading]	rr_BarChartHeading	ANNUAL RETURN CLASS A SHARES (%)<br/>(Year ended December 31)
Bar Chart Does Not Reflect Sales Loads [Text]	rr_BarChartDoesNotReflectSalesLoads	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.
Bar Chart Closing [Text Block]	rr_BarChartClosingTextBlock	For the period covered by the bar chart: THE HIGHEST CALENDAR QUARTERLY RETURN WAS 21.23% (07/01/2009 TO 09/30/2009). THE LOWEST CALENDAR QUARTERLY RETURN WAS -23.20% (10/01/2008 TO 12/31/2008). At September 30, 2018, the year-to-date return was 3.77%.
Performance Table Heading	rr_PerformanceTableHeading	AVERAGE ANNUAL TOTAL RETURN (%) <br/><br/>(for periods ended December 31, 2017)
Performance Table Uses Highest Federal Rate	rr_PerformanceTableUsesHighestFederalRate	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.
Performance Table Not Relevant to Tax Deferred	rr_PerformanceTableNotRelevantToTaxDeferred	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.
Performance Table One Class of after Tax Shown [Text]	rr_PerformanceTableOneClassOfAfterTaxShown	After-tax returns are shown only for Class A shares. After-tax returns for Class C, Class K and Class Y shares will vary.
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 K and Class Y shares will vary.
Performance Table Closing [Text Block]	rr_PerformanceTableClosingTextBlock	No performance information is presented for Class K shares in the table because Class K shares do not have annual returns for at least one calendar year. The returns for Class K shares would differ from those of other classes of shares because they have different expenses.
Pioneer High Income Municipal Fund | CLASS A
Risk/Return:	rr_RiskReturnAbstract
Maximum sales charge (load) when you buy shares (as a percentage of offering price)	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	4.50%
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	[1]
Management Fees	rr_ManagementFeesOverAssets	0.50%
Distribution and Service (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	0.25%
Other Expenses	rr_OtherExpensesOverAssets	0.11%	[2]
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	0.86%
Less: Fee Waiver and Expense Reimbursement	rr_FeeWaiverOrReimbursementOverAssets	(0.03%)	[3]
Net Expenses	rr_NetExpensesOverAssets	0.83%	[3]
1	rr_ExpenseExampleYear01	$ 531
3	rr_ExpenseExampleYear03	709
5	rr_ExpenseExampleYear05	903
10	rr_ExpenseExampleYear10	1,460
1	rr_ExpenseExampleNoRedemptionYear01	531
3	rr_ExpenseExampleNoRedemptionYear03	709
5	rr_ExpenseExampleNoRedemptionYear05	903
10	rr_ExpenseExampleNoRedemptionYear10	$ 1,460
2008	rr_AnnualReturn2008	(30.80%)
2009	rr_AnnualReturn2009	34.06%
2010	rr_AnnualReturn2010	6.88%
2011	rr_AnnualReturn2011	1.73%
2012	rr_AnnualReturn2012	20.90%
2013	rr_AnnualReturn2013	(8.17%)
2014	rr_AnnualReturn2014	10.63%
2015	rr_AnnualReturn2015	5.63%
2016	rr_AnnualReturn2016	1.49%
2017	rr_AnnualReturn2017	8.23%
Year to Date Return, Label	rr_YearToDateReturnLabel	year-to-date return
Bar Chart, Year to Date Return, Date	rr_BarChartYearToDateReturnDate	Sep. 30, 2018
Bar Chart, Year to Date Return	rr_BarChartYearToDateReturn	3.77%
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	HIGHEST CALENDAR QUARTERLY RETURN
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Sep. 30, 2009
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	21.23%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	LOWEST CALENDAR QUARTERLY RETURN
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Dec. 31, 2008
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	(23.20%)
1 YEAR	rr_AverageAnnualReturnYear01	3.42%
5 YEARS	rr_AverageAnnualReturnYear05	2.41%
10 YEARS	rr_AverageAnnualReturnYear10	3.22%
SINCE INCEPTION	rr_AverageAnnualReturnSinceInception	2.89%
INCEPTION DATE	rr_AverageAnnualReturnInceptionDate	Oct. 17, 2006
Pioneer High Income Municipal Fund | CLASS C
Risk/Return:	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	0.50%
Distribution and Service (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	1.00%
Other Expenses	rr_OtherExpensesOverAssets	0.13%	[2]
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	1.63%
Less: Fee Waiver and Expense Reimbursement	rr_FeeWaiverOrReimbursementOverAssets	none	[3]
Net Expenses	rr_NetExpensesOverAssets	1.63%	[3]
1	rr_ExpenseExampleYear01	$ 266
3	rr_ExpenseExampleYear03	514
5	rr_ExpenseExampleYear05	887
10	rr_ExpenseExampleYear10	1,933
1	rr_ExpenseExampleNoRedemptionYear01	166
3	rr_ExpenseExampleNoRedemptionYear03	514
5	rr_ExpenseExampleNoRedemptionYear05	887
10	rr_ExpenseExampleNoRedemptionYear10	$ 1,933
1 YEAR	rr_AverageAnnualReturnYear01	7.26%
5 YEARS	rr_AverageAnnualReturnYear05	2.56%
10 YEARS	rr_AverageAnnualReturnYear10	2.88%
SINCE INCEPTION	rr_AverageAnnualReturnSinceInception	2.48%
INCEPTION DATE	rr_AverageAnnualReturnInceptionDate	Oct. 17, 2006
Pioneer High Income Municipal Fund | CLASS K
Risk/Return:	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	0.50%
Distribution and Service (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	none
Other Expenses	rr_OtherExpensesOverAssets	0.10%	[2]
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	0.60%
Less: Fee Waiver and Expense Reimbursement	rr_FeeWaiverOrReimbursementOverAssets	none	[3]
Net Expenses	rr_NetExpensesOverAssets	0.60%	[3]
1	rr_ExpenseExampleYear01	$ 61
3	rr_ExpenseExampleYear03	192
5	rr_ExpenseExampleYear05	335
10	rr_ExpenseExampleYear10	750
1	rr_ExpenseExampleNoRedemptionYear01	61
3	rr_ExpenseExampleNoRedemptionYear03	192
5	rr_ExpenseExampleNoRedemptionYear05	335
10	rr_ExpenseExampleNoRedemptionYear10	$ 750
Pioneer High Income Municipal Fund | CLASS Y
Risk/Return:	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	0.50%
Distribution and Service (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	none
Other Expenses	rr_OtherExpensesOverAssets	0.18%	[2]
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	0.68%
Less: Fee Waiver and Expense Reimbursement	rr_FeeWaiverOrReimbursementOverAssets	(0.13%)	[3]
Net Expenses	rr_NetExpensesOverAssets	0.55%	[3]
1	rr_ExpenseExampleYear01	$ 56
3	rr_ExpenseExampleYear03	176
5	rr_ExpenseExampleYear05	307
10	rr_ExpenseExampleYear10	689
1	rr_ExpenseExampleNoRedemptionYear01	56
3	rr_ExpenseExampleNoRedemptionYear03	176
5	rr_ExpenseExampleNoRedemptionYear05	307
10	rr_ExpenseExampleNoRedemptionYear10	$ 689
1 YEAR	rr_AverageAnnualReturnYear01	8.31%
5 YEARS	rr_AverageAnnualReturnYear05	3.50%
10 YEARS	rr_AverageAnnualReturnYear10	3.76%
SINCE INCEPTION	rr_AverageAnnualReturnSinceInception	3.32%
INCEPTION DATE	rr_AverageAnnualReturnInceptionDate	Oct. 17, 2006
Pioneer High Income Municipal Fund | Return after taxes on distributions | CLASS A
Risk/Return:	rr_RiskReturnAbstract
1 YEAR	rr_AverageAnnualReturnYear01	3.34%
5 YEARS	rr_AverageAnnualReturnYear05	2.35%
10 YEARS	rr_AverageAnnualReturnYear10	3.18%
SINCE INCEPTION	rr_AverageAnnualReturnSinceInception	2.85%
INCEPTION DATE	rr_AverageAnnualReturnInceptionDate	Oct. 17, 2006
Pioneer High Income Municipal Fund | Return after taxes on distributions and sale of shares | CLASS A
Risk/Return:	rr_RiskReturnAbstract
1 YEAR	rr_AverageAnnualReturnYear01	3.97%
5 YEARS	rr_AverageAnnualReturnYear05	2.97%
10 YEARS	rr_AverageAnnualReturnYear10	3.66%
SINCE INCEPTION	rr_AverageAnnualReturnSinceInception	3.36%
INCEPTION DATE	rr_AverageAnnualReturnInceptionDate	Oct. 17, 2006
Pioneer High Income Municipal Fund | Bloomberg Barclays U.S. Municipal High Yield Bond Index (reflects no deduction for fees, expenses or taxes)
Risk/Return:	rr_RiskReturnAbstract
1 YEAR	rr_AverageAnnualReturnYear01	9.69%
5 YEARS	rr_AverageAnnualReturnYear05	4.35%
10 YEARS	rr_AverageAnnualReturnYear10	5.25%
SINCE INCEPTION	rr_AverageAnnualReturnSinceInception	4.64%
INCEPTION DATE	rr_AverageAnnualReturnInceptionDate	Oct. 17, 2006

[1] Class A purchases of $500,000 or more that are not subject to an initial sales charge may be subject to a contingent deferred sales charge of 1%. See "Sales charges."

[2] Other expenses for Class K shares are estimated for the current year.

[3] 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 0.55% of the average daily net assets attributable to Class A and Class Y shares, respectively. These expense limitations are in effect through December 31, 2019. There can be no assurance that the adviser will extend the expense limitations beyond such time. While in effect, the arrangement may be terminated for a class only by agreement of the adviser and the Board of Trustees.