S000016628 [Member] Investment Risks - Western Asset Managed Municipals Fund	Feb. 28, 2025
Market events risk [Member]
Prospectus [Line Items]
Risk [Text Block]	Market events risk. The market values of securities or other assets will fluctuate, sometimes sharply and unpredictably, due to factors such as economic events, governmental actions or intervention, actions taken by the U.S. Federal Reserve or foreign central banks, market disruptions caused by trade disputes, labor strikes or other factors, political developments, armed conflicts, economic sanctions and countermeasures in response to sanctions, major cybersecurity events, the global and domestic effects of widespread or local health, weather or climate events, and other factors that may or may not be related to the issuer of the security or other asset. Economies and financial markets throughout the world are increasingly interconnected. Economic, financial or political events, trading and tariff arrangements, public health events, terrorism, wars, 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 or markets directly affected, the value and liquidity of the fund’s investments may be negatively affected. Ongoing armed conflicts between Russia and Ukraine in Europe and among Israel, Hamas and other militant groups in the Middle East have caused and could continue to cause significant market disruptions and volatility. The hostilities and sanctions resulting from those hostilities have and could continue to have a significant impact on certain fund investments as well as fund performance and liquidity. Following Russia’s invasion of Ukraine in 2022, Russian stocks lost all, or nearly all, of their market value. Other securities or markets could be similarly affected by past or future geopolitical or other events or conditions. Furthermore, events involving limited liquidity, defaults, non-performance or other adverse developments that affect one industry, such as the financial services industry, or concerns or rumors about any events of these kinds, have in the past and may in the future lead to market-wide liquidity problems, may spread to other industries, and could negatively affect the value and liquidity of the fund’s investments. 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. Recently, inflation and interest rates have been volatile and may increase in the future. 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.
Inflation risk [Member]
Prospectus [Line Items]
Risk [Text Block]	Inflation risk. Inflation risk is the risk that the value of assets or income from investments will be worth less in the future as prices go up and the purchasing power of money goes down. The market prices of debt securities generally fall as inflation increases because the purchasing power of the principal and income is expected to be less when paid. Inflation often is accompanied or followed by a recession, or period of decline in economic activity, which may include job loss and other hardships and may cause the value of securities to go down generally.
Credit risks [Member]
Prospectus [Line Items]
Risk [Text Block]	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 or its credit is downgraded, or is perceived to be less creditworthy, or if the value of the assets underlying a security 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. Subordinated securities (meaning securities that rank below other securities with respect to claims on the issuer’s assets) are more likely to suffer a credit loss than non-subordinated securities of the same issuer and will be disproportionately affected by a default, downgrade or perceived decline in creditworthiness.
High yield junk bonds risk [Member]
Prospectus [Line Items]
Risk [Text Block]	High yield (“junk”) bonds risk. High yield bonds are generally subject to greater credit risks than higher-grade bonds, including the risk of default on the payment of interest or principal. High yield bonds are considered speculative, typically have lower liquidity and are more difficult to value than higher grade bonds. High yield bonds tend to be volatile and more susceptible to adverse events, credit downgrades and negative sentiments and may be difficult to sell at a desired price, or at all, during periods of uncertainty or market turmoil.
Leverage risk [Member]
Prospectus [Line Items]
Risk [Text Block]	Leverage risk. The value of your investment may be more volatile if the fund borrows or uses instruments, such as derivatives, that have a leveraging effect on the fund’s portfolio. Other risks described in the Prospectus also will be compounded because leverage generally magnifies the effect of a change in the value of an asset and creates a risk of loss of value on a larger pool of assets than the fund would otherwise have had. The fund may also have to sell assets at inopportune times to satisfy its obligations created by the use of leverage or derivatives. The use of leverage is considered to be a speculative investment practice and may result in the loss of a substantial amount, and possibly all, of the fund’s assets. In addition, the fund’s portfolio will be leveraged if it exercises its right to delay payment on a redemption, and losses will result if the value of the fund’s assets declines between the time a redemption request is deemed to be received by the fund and the time the fund liquidates assets to meet redemption requests.
Tender option bond risk [Member]
Prospectus [Line Items]
Risk [Text Block]	Tender option bond risk. Tender option bond (“TOB”) transactions expose the fund to leverage and credit risk, and generally involve greater risk than direct investments in fixed rate municipal bonds, including the risk of loss of principal. The interest payments that the fund would typically receive in connection with a TOB transaction (“inverse floaters”) vary inversely with short-term interest rates and will be reduced (and potentially eliminated) when short-term interest rates increase. In addition, the fund will be subject to leverage risk to the extent that the fund uses the proceeds that it receives from a TOB transaction to invest in other securities. The fund’s investment in a TOB will generally underperform the market for fixed rate municipal securities when interest rates rise. The value and market for such inverse floaters can be volatile and can have limited liquidity. Investments in inverse floaters issued in TOB transactions are derivative instruments and, therefore, are also subject to the risks generally applicable to investments in derivatives.
Illiquidity risk [Member]
Prospectus [Line Items]
Risk [Text Block]	Illiquidity risk. Some assets held by the fund may be or become impossible or difficult to sell and some assets that the fund wants to invest in may be impossible or difficult to purchase, particularly during times of market turmoil or due to adverse changes in the conditions of a particular issuer. These illiquid assets may also be volatile and difficult to value. Markets may become illiquid quickly. Markets may become illiquid when, for instance, there are few, if any, interested buyers or sellers or when dealers are unwilling or unable to make a market for certain securities. As a general matter, dealers have been less willing to make markets in recent years. Federal banking regulations may also cause certain dealers to reduce their inventories of certain securities, which may further decrease the fund’s ability to buy or sell such securities. 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 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).
Transportation bond risk [Member]
Prospectus [Line Items]
Risk [Text Block]	Transportation bond risk. Certain facility revenue bonds are payable from and secured by the revenue from the ownership and operation of particular facilities, such as airports, highways, port authorities or other transit facilities. Airport operating income may be affected by the general stability of the airline industry and on the ability of airlines to meet their obligations under agreements with airports. Similarly, payment on bonds related to other facilities is dependent on revenues from the projects, such as use fees from ports, tolls on turnpikes and bridges and rents from buildings. Therefore, payment may be adversely affected by reduction in revenues due to such factors and increased cost of maintenance or decreased use of a facility. Fuel costs, transportation taxes and fees, and availability of fuel also affect other transportation-related securities, as do the presence of alternate forms of transportation, such as public transportation. The portfolio manager cannot predict what effect conditions may have on revenues which are required for payment on these bonds.
Tax risk [Member]
Prospectus [Line Items]
Risk [Text Block]	Tax risk. The income on the fund’s municipal securities could become subject to U.S. federal income tax due to noncompliant conduct by issuers, unfavorable legislation or litigation or adverse interpretations by regulatory authorities. All or a portion of the fund’s dividends that are exempt from regular U.S. federal income tax may nevertheless be taken into account for purposes of the U.S. federal alternative minimum tax.
Prepayment or call risk [Member]
Prospectus [Line Items]
Risk [Text Block]	Prepayment or call risk. Many issuers have a right to prepay their fixed income securities. Issuers may be more likely to prepay their securities if interest rates fall. If this happens, the fund may not benefit from the rise in the market price of the securities 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 prepaid securities. The fund may also lose any premium it paid to purchase the securities.
Extension risk [Member]
Prospectus [Line Items]
Risk [Text Block]	Extension risk. When interest rates rise, repayments of fixed income securities, particularly asset- and mortgage-backed securities, may occur more slowly than anticipated, extending the effective duration of these fixed income securities at below market interest rates and causing their market prices to decline more than they would have declined due to the rise in interest rates alone. This may cause the fund’s share price to be more volatile.
Risk of investing in fewer issuers [Member]
Prospectus [Line Items]
Risk [Text Block]	Risk of investing in fewer issuers. To the extent the fund invests its assets in a small number of issuers, or in issuers in related businesses or that are subject to related operating risks, the fund will be more susceptible to negative events affecting those issuers.
Risks relating to investments in municipal securities [Member]
Prospectus [Line Items]
Risk [Text Block]	Risks relating to investments in municipal securities. 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. 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. In the past, a number of municipal issuers defaulted on obligations, were downgraded or commenced insolvency proceedings. Financial difficulties of municipal issuers may experience a resurgence, particularly in the event of economic or market turmoil or a recession.
Investing in ETFs risk [Member]
Prospectus [Line Items]
Risk [Text Block]	Investing in ETFs risk. Unlike shares of typical mutual funds or unit investment trusts, shares of exchange-traded funds (“ETFs”) are traded on an exchange and may trade throughout a trading day. ETFs are bought and sold based on market values and not at net asset value, and therefore may trade at either a premium or discount to net asset value and may experience volatility in certain market conditions. The fund will pay brokerage commissions in connection with the purchase and sales of shares of ETFs. In addition, the fund will indirectly bear its pro rata share of fees and expenses incurred by an ETF in which it invests, including advisory fees. These expenses are in addition to management fees and other expenses that the fund bears directly in connection with its own operations. Certain ETFs are also subject to portfolio management risk. Investments in ETFs are subject to the risk that the listing exchange may halt trading of an ETF’s shares, in which case the fund would be unable to sell its ETF shares unless and until trading is resumed.
Valuation risk [Member]
Prospectus [Line Items]
Risk [Text Block]	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 securities that trade in thin or volatile markets or that are valued using a fair value methodology. These differences may increase significantly and affect fund investments more broadly during periods of market volatility. 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 securities or had used a different valuation methodology. The fund’s ability to value its investments may be impacted by technological issues and/or errors by pricing services or other third party service providers. The valuation of the fund’s investments involves subjective judgment, which may prove to be incorrect.
Portfolio management risk [Member]
Prospectus [Line Items]
Risk [Text Block]	Portfolio management risk. The value of your investment may decrease if the subadviser’s judgment about the quality, relative yield, value or market trends affecting a particular security, industry, sector or region, or about interest rates or other market factors, is incorrect or does not produce the desired results, or if there are imperfections, errors or limitations in the models, tools and data used by the subadviser. In addition, the fund’s investment strategies or policies may change from time to time. Those changes may not lead to the results intended by the subadviser and could have an adverse effect on the value or performance of the fund.
Redemption risk [Member]
Prospectus [Line Items]
Risk [Text Block]	Redemption risk. The fund may experience heavy redemptions that could cause the fund to liquidate its assets at inopportune times or unfavorable prices or increase or accelerate taxable gains or transaction costs and may negatively affect the fund’s net asset value, performance, or ability to satisfy redemptions in a timely manner, which could cause the value of your investment to decline.
Cybersecurity risk [Member]
Prospectus [Line Items]
Risk [Text Block]	Cybersecurity risk. Like other funds and business enterprises, the fund, the manager, the subadviser and their service providers are subject to the risk of cyber incidents occurring from time to time. Cybersecurity incidents, whether intentionally caused by third parties or otherwise, may allow an unauthorized party to gain access to fund assets, fund or customer data (including private shareholder information) or proprietary information, cause the fund, the manager, the subadviser and/or their service providers (including, but not limited to, fund accountants, custodians, sub-custodians, transfer agents and financial intermediaries) to suffer data breaches, data corruption or loss of operational functionality, or prevent fund investors from purchasing, redeeming or exchanging shares, receiving distributions or receiving timely information regarding the fund or their investment in the fund. The fund, the manager, and the subadviser have limited ability to prevent or mitigate cybersecurity incidents affecting third party service providers, and such third party service providers may have limited indemnification obligations to the fund, the manager, and/or the subadviser. Cybersecurity incidents may result in financial losses to the fund and its shareholders, and substantial costs may be incurred in order to prevent or mitigate any future cybersecurity incidents. Issuers of securities in which the fund invests are also subject to cybersecurity risks, and the value of these securities could decline if the issuers experience cybersecurity incidents. New ways to carry out cyber attacks continue to develop. 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.
Derivatives risks [Member]
Prospectus [Line Items]
Risk [Text Block]	Derivatives risk. Using derivatives can increase fund losses and reduce opportunities for gains, such as when market prices, interest rates, or the derivatives themselves, behave in a way not anticipated by the fund’s subadviser. Using derivatives also can have a leveraging effect and increase fund volatility. Certain derivatives have the potential for unlimited loss, regardless of the size of the initial investment. Derivatives may not be available at the time or price desired, may be difficult to sell, unwind or value, and the counterparty may default on its obligations to the fund. Derivatives are generally subject to the risks applicable to the assets, rates, indices or other indicators underlying the derivative. The value of a derivative may fluctuate more than the underlying assets, rates, indices or other indicators to which it relates. Use of derivatives may have different tax consequences for the fund than an investment in the underlying asset, and those differences may affect the amount, timing and character of income distributed to shareholders, including the proportion of income consisting of exempt-interest dividends. The U.S. government and non-U.S. governments have adopted and implemented 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 derivatives more costly, limit their availability or utility, otherwise adversely affect their performance or disrupt markets.
Market and interest rate risk [Member]
Prospectus [Line Items]
Risk [Text Block]	Market and interest rate risk. The market prices of securities held by the fund may go up or down, sometimes rapidly or unpredictably. If the market prices of the fund’s securities fall, the value of your investment in the fund will decline. The market price of a security may fall due to general market conditions, such as real or perceived adverse economic or political conditions or trends, tariffs and trade disruptions, inflation, substantial economic downturn or recession, changes in interest rates, lack of liquidity in the bond markets or adverse investor sentiment. Changes in market conditions will not typically have the same impact on all types of securities. 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. A general rise in interest rates may cause investors to move out of fixed income securities on a large scale, which could adversely affect the price and liquidity of fixed income securities and could also result in increased redemptions from the fund. Recently, there have been inflationary price movements. As a result, fixed income securities markets may experience heightened levels of interest rate volatility and liquidity risk. The U.S. government and the U.S. Federal Reserve, as well as certain foreign governments and central banks, have from time to time taken steps to support financial markets. The U.S. government and the U.S. Federal Reserve may, conversely, reduce market support activities, including by taking action intended to increase certain interest rates. This and other government intervention may not work as intended, particularly if the efforts are perceived by investors as being unlikely to achieve the desired results. Changes in government activities in this regard, such as changes in interest rate policy, can negatively affect financial markets generally, increase market volatility and reduce the value and liquidity of securities in which the fund invests. The maturity of a security may be significantly longer than its duration. A security’s maturity and other features may be more relevant than its 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.
Risk Lose Money [Member]
Prospectus [Line Items]
Risk [Text Block]	You may lose part or all of your investment in the fund or your investment may not perform as well as other similar investments.
Risk Not Insured Depository Institution [Member]
Prospectus [Line Items]
Risk [Text Block]	An investment in the fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or by any bank or government agency.

S000016628 [Member] Investment Risks - Western Asset Managed Municipals Fund

Feb. 28, 2025

Market events risk. The market values of securities or other assets will fluctuate, sometimes sharply and unpredictably, due to factors such as economic events, governmental actions or intervention, actions taken by the U.S. Federal Reserve or foreign central banks, market disruptions caused by trade disputes, labor strikes or other factors, political developments, armed conflicts, economic sanctions and countermeasures in response to sanctions, major cybersecurity events, the global and domestic effects of widespread or local health, weather or climate events, and other factors that may or may not be related to the issuer of the security or other asset. Economies and financial markets throughout the world are increasingly interconnected. Economic, financial or political events, trading and tariff arrangements, public health events, terrorism, wars, 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 or markets directly affected, the value and liquidity of the fund’s investments may be negatively affected. Ongoing armed conflicts between Russia and Ukraine in Europe and among Israel, Hamas and other militant groups in the Middle East have caused and could continue to cause significant market disruptions and volatility. The hostilities and sanctions resulting from those hostilities have and could continue to have a significant impact on certain fund investments as well as fund performance and liquidity. Following Russia’s invasion of Ukraine in 2022, Russian stocks lost all, or nearly all, of their market value. Other securities or markets could be similarly affected by past or future geopolitical or other events or conditions. Furthermore, events involving limited liquidity, defaults, non-performance or other adverse developments that affect one industry, such as the financial services industry, or concerns or rumors about any events of these kinds, have in the past and may in the future lead to market-wide liquidity problems, may spread to other industries, and could negatively affect the value and liquidity of the fund’s investments.

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. Recently, inflation and interest rates have been volatile and may increase in the future. 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.