Risk/Return Summary - FidelityFlexMunicipalIncomeFund-PRO - FidelityFlexMunicipalIncomeFund-PRO - Fidelity Flex Municipal Income Fund	Mar. 01, 2025
Risk Lose Money [Text]
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Risk Text Block	You could lose money by investing in the fund.
Risk Not Insured Depository Institution [Text]
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Risk Text Block	An investment in the fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency .
InterestRateChangesMember
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Risk Text Block	Interest Rate Changes. Interest rate increases can cause the price of a debt security to decrease.
IssuerSpecificChangesMember
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Risk Text Block	Issuer-Specific Changes. The value of an individual security or particular type of security can be more volatile than, and can perform differently from, the market as a whole. A decline in the credit quality of an issuer or a provider of credit support (such as guarantees) or a maturity-shortening structure (such as demand and put features) for a security can cause the price of a security to decrease.
MunicipalMarketVolatilityMember
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Risk Text Block	Municipal Market Volatility. The municipal market is volatile and can be significantly affected by adverse tax, legislative, or political changes and the financial condition of the issuers of municipal securities.

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

Risk Text Block

Issuer-Specific Changes. The value of an individual security or particular type of security can be more volatile than, and can perform differently from, the market as a whole. A decline in the credit quality of an issuer or a provider of credit support (such as guarantees) or a maturity-shortening structure (such as demand and put features) for a security can cause the price of a security to decrease.

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