v3.26.3
Shareholder Report, Holdings (Details)
Aug. 31, 2026
Fidelity Total Bond ETF | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 25.60%
Fidelity Total Bond ETF | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 12.30%
Fidelity Total Bond ETF | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 5.00%
Fidelity Total Bond ETF | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 4.10%
Fidelity Total Bond ETF | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.40%
Fidelity Total Bond ETF | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.00%
Fidelity Total Bond ETF | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.60%
Fidelity Total Bond ETF | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity Total Bond ETF | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
Fidelity Total Bond ETF | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
Fidelity Total Bond ETF | QDUSGovernmentandUSGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 54.30%
Fidelity Total Bond ETF | QDAAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.50%
Fidelity Total Bond ETF | QDAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.50%
Fidelity Total Bond ETF | QDAMember  
Holdings [Line Items]  
Percent of Net Asset Value 8.80%
Fidelity Total Bond ETF | QDBBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 15.10%
Fidelity Total Bond ETF | QDBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.10%
Fidelity Total Bond ETF | QDBMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.80%
Fidelity Total Bond ETF | QDCCCCCCMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.70%
Fidelity Total Bond ETF | QDDMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Total Bond ETF | QDNotRatedMember  
Holdings [Line Items]  
Percent of Net Asset Value 8.20%
Fidelity Total Bond ETF | QDEquitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Total Bond ETF | United States  
Holdings [Line Items]  
Percent of Net Asset Value 87.70%
Fidelity Total Bond ETF | GrandCaymanUKOverseasTerMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.00%
Fidelity Total Bond ETF | United Kingdom  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Total Bond ETF | Mexico  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
Fidelity Total Bond ETF | BailiwickOfJerseyMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.80%
Fidelity Total Bond ETF | Germany  
Holdings [Line Items]  
Percent of Net Asset Value 0.60%
Fidelity Total Bond ETF | Ireland  
Holdings [Line Items]  
Percent of Net Asset Value 0.60%
Fidelity Total Bond ETF | Canada  
Holdings [Line Items]  
Percent of Net Asset Value 0.50%
Fidelity Total Bond ETF | Switzerland  
Holdings [Line Items]  
Percent of Net Asset Value 0.40%
Fidelity Total Bond ETF | OtherMember  
Holdings [Line Items]  
Percent of Net Asset Value 3.00%
Fidelity Total Bond ETF | AAUSTreasuryObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 37.90%
Fidelity Total Bond ETF | AACorporateBondsMember  
Holdings [Line Items]  
Percent of Net Asset Value 25.60%
Fidelity Total Bond ETF | AAUSGovernmentAgencyMortgageSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 16.40%
Fidelity Total Bond ETF | AAAssetBackedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 8.60%
Fidelity Total Bond ETF | AACMOsandOtherMortgageRelatedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 6.80%
Fidelity Total Bond ETF | AABankLoanObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.20%
Fidelity Total Bond ETF | AAForeignGovernmentandGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Total Bond ETF | AAPreferredSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Total Bond ETF | AAOptionsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Total Bond ETF | AAPreferredStocksMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Total Bond ETF | AAOtherInvestmentsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Total Bond ETF | AACommonStocksMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Tactical Bond ETF | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 33.10%
Fidelity Tactical Bond ETF | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 17.00%
Fidelity Tactical Bond ETF | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.90%
Fidelity Tactical Bond ETF | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity Tactical Bond ETF | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity Tactical Bond ETF | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity Tactical Bond ETF | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity Tactical Bond ETF | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Tactical Bond ETF | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.80%
Fidelity Tactical Bond ETF | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.70%
Fidelity Tactical Bond ETF | QDUSGovernmentandUSGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 50.10%
Fidelity Tactical Bond ETF | QDAAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity Tactical Bond ETF | QDAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Tactical Bond ETF | QDAMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.90%
Fidelity Tactical Bond ETF | QDBBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 11.70%
Fidelity Tactical Bond ETF | QDBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 13.60%
Fidelity Tactical Bond ETF | QDBMember  
Holdings [Line Items]  
Percent of Net Asset Value 7.60%
Fidelity Tactical Bond ETF | QDCCCCCCMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.60%
Fidelity Tactical Bond ETF | QDNotRatedMember  
Holdings [Line Items]  
Percent of Net Asset Value 3.70%
Fidelity Tactical Bond ETF | QDEquitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.00%
Fidelity Tactical Bond ETF | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.60%
Fidelity Tactical Bond ETF | United States  
Holdings [Line Items]  
Percent of Net Asset Value 83.40%
Fidelity Tactical Bond ETF | United Kingdom  
Holdings [Line Items]  
Percent of Net Asset Value 2.50%
Fidelity Tactical Bond ETF | Mexico  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity Tactical Bond ETF | Germany  
Holdings [Line Items]  
Percent of Net Asset Value 1.90%
Fidelity Tactical Bond ETF | Canada  
Holdings [Line Items]  
Percent of Net Asset Value 2.40%
Fidelity Tactical Bond ETF | Switzerland  
Holdings [Line Items]  
Percent of Net Asset Value 0.80%
Fidelity Tactical Bond ETF | OtherMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.10%
Fidelity Tactical Bond ETF | Brazil  
Holdings [Line Items]  
Percent of Net Asset Value 1.60%
Fidelity Tactical Bond ETF | Luxembourg  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
Fidelity Tactical Bond ETF | Guatemala  
Holdings [Line Items]  
Percent of Net Asset Value 0.80%
Fidelity Tactical Bond ETF | AAUSTreasuryObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 50.10%
Fidelity Tactical Bond ETF | AACorporateBondsMember  
Holdings [Line Items]  
Percent of Net Asset Value 30.20%
Fidelity Tactical Bond ETF | AAAssetBackedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.10%
Fidelity Tactical Bond ETF | AACMOsandOtherMortgageRelatedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
Fidelity Tactical Bond ETF | AABankLoanObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.50%
Fidelity Tactical Bond ETF | AAForeignGovernmentandGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 3.90%
Fidelity Tactical Bond ETF | AAPreferredSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.40%
Fidelity Tactical Bond ETF | AAPreferredStocksMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.10%
Fidelity Tactical Bond ETF | AACommonStocksMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Tactical Bond ETF | AAFixedIncomeFundsMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.90%
Fidelity Tactical Bond ETF | AAMunicipalSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.10%
Fidelity Tactical Bond ETF | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.60%
Fidelity Low Duration Bond Factor ETF | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 12.00%
Fidelity Low Duration Bond Factor ETF | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.70%
Fidelity Low Duration Bond Factor ETF | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.60%
Fidelity Low Duration Bond Factor ETF | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.50%
Fidelity Low Duration Bond Factor ETF | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.30%
Fidelity Low Duration Bond Factor ETF | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.10%
Fidelity Low Duration Bond Factor ETF | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.10%
Fidelity Low Duration Bond Factor ETF | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.00%
Fidelity Low Duration Bond Factor ETF | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.90%
Fidelity Low Duration Bond Factor ETF | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.80%
Fidelity Low Duration Bond Factor ETF | QDUSGovernmentandUSGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 12.20%
Fidelity Low Duration Bond Factor ETF | QDAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 27.80%
Fidelity Low Duration Bond Factor ETF | QDAMember  
Holdings [Line Items]  
Percent of Net Asset Value 51.80%
Fidelity Low Duration Bond Factor ETF | QDBBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 6.90%
Fidelity Low Duration Bond Factor ETF | QDBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.30%
Fidelity Low Duration Bond Factor ETF | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity Low Duration Bond Factor ETF | United States  
Holdings [Line Items]  
Percent of Net Asset Value 56.30%
Fidelity Low Duration Bond Factor ETF | United Kingdom  
Holdings [Line Items]  
Percent of Net Asset Value 5.90%
Fidelity Low Duration Bond Factor ETF | Germany  
Holdings [Line Items]  
Percent of Net Asset Value 3.00%
Fidelity Low Duration Bond Factor ETF | Canada  
Holdings [Line Items]  
Percent of Net Asset Value 7.40%
Fidelity Low Duration Bond Factor ETF | OtherMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.50%
Fidelity Low Duration Bond Factor ETF | Australia  
Holdings [Line Items]  
Percent of Net Asset Value 10.50%
Fidelity Low Duration Bond Factor ETF | Japan  
Holdings [Line Items]  
Percent of Net Asset Value 5.80%
Fidelity Low Duration Bond Factor ETF | Netherlands  
Holdings [Line Items]  
Percent of Net Asset Value 3.00%
Fidelity Low Duration Bond Factor ETF | France  
Holdings [Line Items]  
Percent of Net Asset Value 2.20%
Fidelity Low Duration Bond Factor ETF | Spain  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity Low Duration Bond Factor ETF | AAUSTreasuryObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 12.20%
Fidelity Low Duration Bond Factor ETF | AACorporateBondsMember  
Holdings [Line Items]  
Percent of Net Asset Value 86.80%
Fidelity Low Duration Bond Factor ETF | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity Limited Term Bond ETF | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 12.30%
Fidelity Limited Term Bond ETF | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.60%
Fidelity Limited Term Bond ETF | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.60%
Fidelity Limited Term Bond ETF | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity Limited Term Bond ETF | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity Limited Term Bond ETF | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Limited Term Bond ETF | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
Fidelity Limited Term Bond ETF | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
Fidelity Limited Term Bond ETF | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
Fidelity Limited Term Bond ETF | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity Limited Term Bond ETF | QDUSGovernmentandUSGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 12.30%
Fidelity Limited Term Bond ETF | QDAAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 6.50%
Fidelity Limited Term Bond ETF | QDAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.50%
Fidelity Limited Term Bond ETF | QDAMember  
Holdings [Line Items]  
Percent of Net Asset Value 26.80%
Fidelity Limited Term Bond ETF | QDBBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 37.90%
Fidelity Limited Term Bond ETF | QDBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.10%
Fidelity Limited Term Bond ETF | QDBMember  
Holdings [Line Items]  
Percent of Net Asset Value 3.10%
Fidelity Limited Term Bond ETF | QDCCCCCCMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.70%
Fidelity Limited Term Bond ETF | QDNotRatedMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.10%
Fidelity Limited Term Bond ETF | QDEquitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Limited Term Bond ETF | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity Limited Term Bond ETF | United States  
Holdings [Line Items]  
Percent of Net Asset Value 72.10%
Fidelity Limited Term Bond ETF | GrandCaymanUKOverseasTerMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.50%
Fidelity Limited Term Bond ETF | United Kingdom  
Holdings [Line Items]  
Percent of Net Asset Value 5.50%
Fidelity Limited Term Bond ETF | BailiwickOfJerseyMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Limited Term Bond ETF | Germany  
Holdings [Line Items]  
Percent of Net Asset Value 2.70%
Fidelity Limited Term Bond ETF | Ireland  
Holdings [Line Items]  
Percent of Net Asset Value 1.80%
Fidelity Limited Term Bond ETF | Canada  
Holdings [Line Items]  
Percent of Net Asset Value 3.70%
Fidelity Limited Term Bond ETF | OtherMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.90%
Fidelity Limited Term Bond ETF | Japan  
Holdings [Line Items]  
Percent of Net Asset Value 1.60%
Fidelity Limited Term Bond ETF | France  
Holdings [Line Items]  
Percent of Net Asset Value 1.90%
Fidelity Limited Term Bond ETF | AAUSTreasuryObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 12.30%
Fidelity Limited Term Bond ETF | AACorporateBondsMember  
Holdings [Line Items]  
Percent of Net Asset Value 71.50%
Fidelity Limited Term Bond ETF | AAUSGovernmentAgencyMortgageSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Limited Term Bond ETF | AAAssetBackedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 8.90%
Fidelity Limited Term Bond ETF | AACMOsandOtherMortgageRelatedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 3.40%
Fidelity Limited Term Bond ETF | AABankLoanObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Limited Term Bond ETF | AAForeignGovernmentandGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.80%
Fidelity Limited Term Bond ETF | AAPreferredSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.70%
Fidelity Limited Term Bond ETF | AAPreferredStocksMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Limited Term Bond ETF | AAOtherInvestmentsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.10%
Fidelity Limited Term Bond ETF | AACommonStocksMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Limited Term Bond ETF | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity Investment Grade Securitized ETF | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 28.90%
Fidelity Investment Grade Securitized ETF | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 22.80%
Fidelity Investment Grade Securitized ETF | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 20.70%
Fidelity Investment Grade Securitized ETF | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 10.70%
Fidelity Investment Grade Securitized ETF | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 7.30%
Fidelity Investment Grade Securitized ETF | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.70%
Fidelity Investment Grade Securitized ETF | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.30%
Fidelity Investment Grade Securitized ETF | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.80%
Fidelity Investment Grade Securitized ETF | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity Investment Grade Securitized ETF | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity Investment Grade Securitized ETF | QDUSGovernmentandUSGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 86.60%
Fidelity Investment Grade Securitized ETF | QDAAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 10.90%
Fidelity Investment Grade Securitized ETF | QDAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.80%
Fidelity Investment Grade Securitized ETF | QDAMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.10%
Fidelity Investment Grade Securitized ETF | QDCCCCCCMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Investment Grade Securitized ETF | QDNotRatedMember  
Holdings [Line Items]  
Percent of Net Asset Value 22.70%
Fidelity Investment Grade Securitized ETF | United States  
Holdings [Line Items]  
Percent of Net Asset Value 100.00%
Fidelity Investment Grade Securitized ETF | Canada  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Investment Grade Securitized ETF | AAUSTreasuryObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 3.70%
Fidelity Investment Grade Securitized ETF | AAUSGovernmentAgencyMortgageSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 82.90%
Fidelity Investment Grade Securitized ETF | AAAssetBackedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 7.60%
Fidelity Investment Grade Securitized ETF | AACMOsandOtherMortgageRelatedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 26.70%
Fidelity Investment Grade Securitized ETF | AAOptionsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Investment Grade Bond ETF | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 34.90%
Fidelity Investment Grade Bond ETF | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 11.90%
Fidelity Investment Grade Bond ETF | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 4.90%
Fidelity Investment Grade Bond ETF | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.90%
Fidelity Investment Grade Bond ETF | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.60%
Fidelity Investment Grade Bond ETF | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.20%
Fidelity Investment Grade Bond ETF | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity Investment Grade Bond ETF | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity Investment Grade Bond ETF | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Investment Grade Bond ETF | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity Investment Grade Bond ETF | QDUSGovernmentandUSGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 62.80%
Fidelity Investment Grade Bond ETF | QDAAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.00%
Fidelity Investment Grade Bond ETF | QDAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.60%
Fidelity Investment Grade Bond ETF | QDAMember  
Holdings [Line Items]  
Percent of Net Asset Value 7.30%
Fidelity Investment Grade Bond ETF | QDBBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 14.40%
Fidelity Investment Grade Bond ETF | QDBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.90%
Fidelity Investment Grade Bond ETF | QDBMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.70%
Fidelity Investment Grade Bond ETF | QDNotRatedMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.30%
Fidelity Investment Grade Bond ETF | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.00%
Fidelity Investment Grade Bond ETF | United States  
Holdings [Line Items]  
Percent of Net Asset Value 92.10%
Fidelity Investment Grade Bond ETF | GrandCaymanUKOverseasTerMember  
Holdings [Line Items]  
Percent of Net Asset Value 3.60%
Fidelity Investment Grade Bond ETF | United Kingdom  
Holdings [Line Items]  
Percent of Net Asset Value 0.70%
Fidelity Investment Grade Bond ETF | Mexico  
Holdings [Line Items]  
Percent of Net Asset Value 0.70%
Fidelity Investment Grade Bond ETF | BailiwickOfJerseyMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.70%
Fidelity Investment Grade Bond ETF | Germany  
Holdings [Line Items]  
Percent of Net Asset Value 0.40%
Fidelity Investment Grade Bond ETF | Ireland  
Holdings [Line Items]  
Percent of Net Asset Value 0.60%
Fidelity Investment Grade Bond ETF | Switzerland  
Holdings [Line Items]  
Percent of Net Asset Value 0.30%
Fidelity Investment Grade Bond ETF | OtherMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.60%
Fidelity Investment Grade Bond ETF | Japan  
Holdings [Line Items]  
Percent of Net Asset Value 0.30%
Fidelity Investment Grade Bond ETF | AAUSTreasuryObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 46.80%
Fidelity Investment Grade Bond ETF | AACorporateBondsMember  
Holdings [Line Items]  
Percent of Net Asset Value 23.00%
Fidelity Investment Grade Bond ETF | AAUSGovernmentAgencyMortgageSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 16.00%
Fidelity Investment Grade Bond ETF | AAAssetBackedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 7.50%
Fidelity Investment Grade Bond ETF | AACMOsandOtherMortgageRelatedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.70%
Fidelity Investment Grade Bond ETF | AAOtherInvestmentsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Investment Grade Bond ETF | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.00%
Fidelity Corporate Bond ETF | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.80%
Fidelity Corporate Bond ETF | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.50%
Fidelity Corporate Bond ETF | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.20%
Fidelity Corporate Bond ETF | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.10%
Fidelity Corporate Bond ETF | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.10%
Fidelity Corporate Bond ETF | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.80%
Fidelity Corporate Bond ETF | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.80%
Fidelity Corporate Bond ETF | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.60%
Fidelity Corporate Bond ETF | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.50%
Fidelity Corporate Bond ETF | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity Corporate Bond ETF | QDUSGovernmentandUSGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 3.20%
Fidelity Corporate Bond ETF | QDAAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity Corporate Bond ETF | QDAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 3.10%
Fidelity Corporate Bond ETF | QDAMember  
Holdings [Line Items]  
Percent of Net Asset Value 27.50%
Fidelity Corporate Bond ETF | QDBBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 58.10%
Fidelity Corporate Bond ETF | QDBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 4.30%
Fidelity Corporate Bond ETF | QDBMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.30%
Fidelity Corporate Bond ETF | QDNotRatedMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.60%
Fidelity Corporate Bond ETF | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.70%
Fidelity Corporate Bond ETF | United States  
Holdings [Line Items]  
Percent of Net Asset Value 82.80%
Fidelity Corporate Bond ETF | United Kingdom  
Holdings [Line Items]  
Percent of Net Asset Value 3.30%
Fidelity Corporate Bond ETF | Germany  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Corporate Bond ETF | Ireland  
Holdings [Line Items]  
Percent of Net Asset Value 3.10%
Fidelity Corporate Bond ETF | Canada  
Holdings [Line Items]  
Percent of Net Asset Value 3.00%
Fidelity Corporate Bond ETF | OtherMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.70%
Fidelity Corporate Bond ETF | Australia  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
Fidelity Corporate Bond ETF | Japan  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Corporate Bond ETF | Netherlands  
Holdings [Line Items]  
Percent of Net Asset Value 0.70%
Fidelity Corporate Bond ETF | France  
Holdings [Line Items]  
Percent of Net Asset Value 0.70%
Fidelity Corporate Bond ETF | AAUSTreasuryObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 3.20%
Fidelity Corporate Bond ETF | AACorporateBondsMember  
Holdings [Line Items]  
Percent of Net Asset Value 91.00%
Fidelity Corporate Bond ETF | AAAssetBackedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.50%
Fidelity Corporate Bond ETF | AACMOsandOtherMortgageRelatedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.70%
Fidelity Corporate Bond ETF | AAForeignGovernmentandGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.50%
Fidelity Corporate Bond ETF | AAPreferredSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.30%
Fidelity Corporate Bond ETF | AAOtherInvestmentsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.10%
Fidelity Corporate Bond ETF | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.70%
Fidelity Low Duration Bond ETF | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 27.30%
Fidelity Low Duration Bond ETF | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.70%
Fidelity Low Duration Bond ETF | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.70%
Fidelity Low Duration Bond ETF | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.60%
Fidelity Low Duration Bond ETF | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity Low Duration Bond ETF | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
Fidelity Low Duration Bond ETF | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
Fidelity Low Duration Bond ETF | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.80%
Fidelity Low Duration Bond ETF | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.80%
Fidelity Low Duration Bond ETF | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.80%
Fidelity Low Duration Bond ETF | QDUSGovernmentandUSGovernmentAgencyObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 27.30%
Fidelity Low Duration Bond ETF | QDAAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 17.20%
Fidelity Low Duration Bond ETF | QDAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.20%
Fidelity Low Duration Bond ETF | QDAMember  
Holdings [Line Items]  
Percent of Net Asset Value 31.50%
Fidelity Low Duration Bond ETF | QDBBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 11.30%
Fidelity Low Duration Bond ETF | QDBBMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.30%
Fidelity Low Duration Bond ETF | QDNotRatedMember  
Holdings [Line Items]  
Percent of Net Asset Value 3.30%
Fidelity Low Duration Bond ETF | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 3.90%
Fidelity Low Duration Bond ETF | United States  
Holdings [Line Items]  
Percent of Net Asset Value 74.50%
Fidelity Low Duration Bond ETF | GrandCaymanUKOverseasTerMember  
Holdings [Line Items]  
Percent of Net Asset Value 3.80%
Fidelity Low Duration Bond ETF | United Kingdom  
Holdings [Line Items]  
Percent of Net Asset Value 5.10%
Fidelity Low Duration Bond ETF | Germany  
Holdings [Line Items]  
Percent of Net Asset Value 1.90%
Fidelity Low Duration Bond ETF | Canada  
Holdings [Line Items]  
Percent of Net Asset Value 5.70%
Fidelity Low Duration Bond ETF | Switzerland  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity Low Duration Bond ETF | OtherMember  
Holdings [Line Items]  
Percent of Net Asset Value 3.70%
Fidelity Low Duration Bond ETF | Japan  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
Fidelity Low Duration Bond ETF | Netherlands  
Holdings [Line Items]  
Percent of Net Asset Value 2.30%
Fidelity Low Duration Bond ETF | Denmark  
Holdings [Line Items]  
Percent of Net Asset Value 0.80%
Fidelity Low Duration Bond ETF | AAUSTreasuryObligationsMember  
Holdings [Line Items]  
Percent of Net Asset Value 27.30%
Fidelity Low Duration Bond ETF | AACorporateBondsMember  
Holdings [Line Items]  
Percent of Net Asset Value 48.10%
Fidelity Low Duration Bond ETF | AAAssetBackedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 18.20%
Fidelity Low Duration Bond ETF | AACMOsandOtherMortgageRelatedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.40%
Fidelity Low Duration Bond ETF | AAOtherInvestmentsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.10%
Fidelity Low Duration Bond ETF | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 3.90%
Fidelity AAA CLO ETF | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.60%
Fidelity AAA CLO ETF | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.60%
Fidelity AAA CLO ETF | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.60%
Fidelity AAA CLO ETF | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity AAA CLO ETF | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity AAA CLO ETF | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity AAA CLO ETF | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity AAA CLO ETF | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity AAA CLO ETF | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity AAA CLO ETF | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity AAA CLO ETF | QDAAAMember  
Holdings [Line Items]  
Percent of Net Asset Value 74.80%
Fidelity AAA CLO ETF | QDNotRatedMember  
Holdings [Line Items]  
Percent of Net Asset Value 24.40%
Fidelity AAA CLO ETF | QDShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.80%
Fidelity AAA CLO ETF | United States  
Holdings [Line Items]  
Percent of Net Asset Value 4.80%
Fidelity AAA CLO ETF | GrandCaymanUKOverseasTerMember  
Holdings [Line Items]  
Percent of Net Asset Value 87.90%
Fidelity AAA CLO ETF | BailiwickOfJerseyMember  
Holdings [Line Items]  
Percent of Net Asset Value 5.90%
Fidelity AAA CLO ETF | Bermuda  
Holdings [Line Items]  
Percent of Net Asset Value 1.20%
Fidelity AAA CLO ETF | MultinationalMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity AAA CLO ETF | AAAssetBackedSecuritiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 99.20%
Fidelity AAA CLO ETF | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.80%