v3.26.3
Shareholder Report, Holdings (Details)
Jul. 31, 2026
Fidelity SAI Convertible Arbitrage Fund | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 28.50%
Fidelity SAI Convertible Arbitrage Fund | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 8.50%
Fidelity SAI Convertible Arbitrage Fund | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 6.70%
Fidelity SAI Convertible Arbitrage Fund | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.60%
Fidelity SAI Convertible Arbitrage Fund | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.50%
Fidelity SAI Convertible Arbitrage Fund | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.40%
Fidelity SAI Convertible Arbitrage Fund | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.40%
Fidelity SAI Convertible Arbitrage Fund | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.20%
Fidelity SAI Convertible Arbitrage Fund | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.50%
Fidelity SAI Convertible Arbitrage Fund | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.40%
Fidelity SAI Convertible Arbitrage Fund | DEFuturesContractsMember  
Holdings [Line Items]  
Percent of Net Asset Value 22.10%
Fidelity SAI Convertible Arbitrage Fund | DESwapsMember  
Holdings [Line Items]  
Percent of Net Asset Value 390.00%
Fidelity SAI Convertible Arbitrage Fund | AASwapsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 76.20%
Fidelity SAI Convertible Arbitrage Fund | AACorporateBondsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 7.20%
Fidelity SAI Convertible Arbitrage Fund | AACommonStocksMember  
Holdings [Line Items]  
Percent of Net Long Exposure 5.60%
Fidelity SAI Convertible Arbitrage Fund | AAUSTreasuryObligationsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 5.60%
Fidelity SAI Convertible Arbitrage Fund | AAFuturesContractsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 4.30%
Fidelity SAI Convertible Arbitrage Fund | AADomesticEquityFundsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 0.30%
Fidelity SAI Convertible Arbitrage Fund | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Long Exposure 0.80%
Fidelity Risk Parity Fund | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 24.00%
Fidelity Risk Parity Fund | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 15.90%
Fidelity Risk Parity Fund | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 11.20%
Fidelity Risk Parity Fund | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 8.20%
Fidelity Risk Parity Fund | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 7.70%
Fidelity Risk Parity Fund | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 5.40%
Fidelity Risk Parity Fund | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 5.20%
Fidelity Risk Parity Fund | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 4.20%
Fidelity Risk Parity Fund | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.70%
Fidelity Risk Parity Fund | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.20%
Fidelity Risk Parity Fund | DEFuturesContractsMember  
Holdings [Line Items]  
Percent of Net Asset Value 15.00%
Fidelity Risk Parity Fund | DESwapsMember  
Holdings [Line Items]  
Percent of Net Asset Value 60.50%
Fidelity Risk Parity Fund | AASwapsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 34.50%
Fidelity Risk Parity Fund | AAFuturesContractsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 8.50%
Fidelity Risk Parity Fund | AADomesticEquityFundsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 21.00%
Fidelity Risk Parity Fund | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Long Exposure 4.90%
Fidelity Risk Parity Fund | AAFixedIncomeFundsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 27.30%
Fidelity Risk Parity Fund | AAInternationalEquityFundsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 3.80%
Fidelity Advisor Risk Parity Fund - Class Z | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 24.00%
Fidelity Advisor Risk Parity Fund - Class Z | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 15.90%
Fidelity Advisor Risk Parity Fund - Class Z | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 11.20%
Fidelity Advisor Risk Parity Fund - Class Z | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 8.20%
Fidelity Advisor Risk Parity Fund - Class Z | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 7.70%
Fidelity Advisor Risk Parity Fund - Class Z | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 5.40%
Fidelity Advisor Risk Parity Fund - Class Z | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 5.20%
Fidelity Advisor Risk Parity Fund - Class Z | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 4.20%
Fidelity Advisor Risk Parity Fund - Class Z | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.70%
Fidelity Advisor Risk Parity Fund - Class Z | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.20%
Fidelity Advisor Risk Parity Fund - Class Z | DEFuturesContractsMember  
Holdings [Line Items]  
Percent of Net Asset Value 15.00%
Fidelity Advisor Risk Parity Fund - Class Z | DESwapsMember  
Holdings [Line Items]  
Percent of Net Asset Value 60.50%
Fidelity Advisor Risk Parity Fund - Class Z | AASwapsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 34.50%
Fidelity Advisor Risk Parity Fund - Class Z | AAFuturesContractsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 8.50%
Fidelity Advisor Risk Parity Fund - Class Z | AADomesticEquityFundsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 21.00%
Fidelity Advisor Risk Parity Fund - Class Z | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Long Exposure 4.90%
Fidelity Advisor Risk Parity Fund - Class Z | AAFixedIncomeFundsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 27.30%
Fidelity Advisor Risk Parity Fund - Class Z | AAInternationalEquityFundsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 3.80%
Fidelity Advisor Risk Parity Fund - Class M | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 24.00%
Fidelity Advisor Risk Parity Fund - Class M | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 15.90%
Fidelity Advisor Risk Parity Fund - Class M | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 11.20%
Fidelity Advisor Risk Parity Fund - Class M | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 8.20%
Fidelity Advisor Risk Parity Fund - Class M | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 7.70%
Fidelity Advisor Risk Parity Fund - Class M | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 5.40%
Fidelity Advisor Risk Parity Fund - Class M | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 5.20%
Fidelity Advisor Risk Parity Fund - Class M | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 4.20%
Fidelity Advisor Risk Parity Fund - Class M | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.70%
Fidelity Advisor Risk Parity Fund - Class M | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.20%
Fidelity Advisor Risk Parity Fund - Class M | DEFuturesContractsMember  
Holdings [Line Items]  
Percent of Net Asset Value 15.00%
Fidelity Advisor Risk Parity Fund - Class M | DESwapsMember  
Holdings [Line Items]  
Percent of Net Asset Value 60.50%
Fidelity Advisor Risk Parity Fund - Class M | AASwapsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 34.50%
Fidelity Advisor Risk Parity Fund - Class M | AAFuturesContractsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 8.50%
Fidelity Advisor Risk Parity Fund - Class M | AADomesticEquityFundsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 21.00%
Fidelity Advisor Risk Parity Fund - Class M | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Long Exposure 4.90%
Fidelity Advisor Risk Parity Fund - Class M | AAFixedIncomeFundsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 27.30%
Fidelity Advisor Risk Parity Fund - Class M | AAInternationalEquityFundsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 3.80%
Fidelity Advisor Risk Parity Fund - Class I | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 24.00%
Fidelity Advisor Risk Parity Fund - Class I | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 15.90%
Fidelity Advisor Risk Parity Fund - Class I | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 11.20%
Fidelity Advisor Risk Parity Fund - Class I | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 8.20%
Fidelity Advisor Risk Parity Fund - Class I | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 7.70%
Fidelity Advisor Risk Parity Fund - Class I | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 5.40%
Fidelity Advisor Risk Parity Fund - Class I | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 5.20%
Fidelity Advisor Risk Parity Fund - Class I | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 4.20%
Fidelity Advisor Risk Parity Fund - Class I | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.70%
Fidelity Advisor Risk Parity Fund - Class I | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.20%
Fidelity Advisor Risk Parity Fund - Class I | DEFuturesContractsMember  
Holdings [Line Items]  
Percent of Net Asset Value 15.00%
Fidelity Advisor Risk Parity Fund - Class I | DESwapsMember  
Holdings [Line Items]  
Percent of Net Asset Value 60.50%
Fidelity Advisor Risk Parity Fund - Class I | AASwapsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 34.50%
Fidelity Advisor Risk Parity Fund - Class I | AAFuturesContractsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 8.50%
Fidelity Advisor Risk Parity Fund - Class I | AADomesticEquityFundsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 21.00%
Fidelity Advisor Risk Parity Fund - Class I | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Long Exposure 4.90%
Fidelity Advisor Risk Parity Fund - Class I | AAFixedIncomeFundsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 27.30%
Fidelity Advisor Risk Parity Fund - Class I | AAInternationalEquityFundsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 3.80%
Fidelity Advisor Risk Parity Fund - Class C | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 24.00%
Fidelity Advisor Risk Parity Fund - Class C | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 15.90%
Fidelity Advisor Risk Parity Fund - Class C | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 11.20%
Fidelity Advisor Risk Parity Fund - Class C | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 8.20%
Fidelity Advisor Risk Parity Fund - Class C | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 7.70%
Fidelity Advisor Risk Parity Fund - Class C | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 5.40%
Fidelity Advisor Risk Parity Fund - Class C | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 5.20%
Fidelity Advisor Risk Parity Fund - Class C | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 4.20%
Fidelity Advisor Risk Parity Fund - Class C | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.70%
Fidelity Advisor Risk Parity Fund - Class C | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.20%
Fidelity Advisor Risk Parity Fund - Class C | DEFuturesContractsMember  
Holdings [Line Items]  
Percent of Net Asset Value 15.00%
Fidelity Advisor Risk Parity Fund - Class C | DESwapsMember  
Holdings [Line Items]  
Percent of Net Asset Value 60.50%
Fidelity Advisor Risk Parity Fund - Class C | AASwapsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 34.50%
Fidelity Advisor Risk Parity Fund - Class C | AAFuturesContractsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 8.50%
Fidelity Advisor Risk Parity Fund - Class C | AADomesticEquityFundsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 21.00%
Fidelity Advisor Risk Parity Fund - Class C | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Long Exposure 4.90%
Fidelity Advisor Risk Parity Fund - Class C | AAFixedIncomeFundsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 27.30%
Fidelity Advisor Risk Parity Fund - Class C | AAInternationalEquityFundsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 3.80%
Fidelity Advisor Risk Parity Fund - Class A | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 24.00%
Fidelity Advisor Risk Parity Fund - Class A | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 15.90%
Fidelity Advisor Risk Parity Fund - Class A | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 11.20%
Fidelity Advisor Risk Parity Fund - Class A | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 8.20%
Fidelity Advisor Risk Parity Fund - Class A | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 7.70%
Fidelity Advisor Risk Parity Fund - Class A | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 5.40%
Fidelity Advisor Risk Parity Fund - Class A | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 5.20%
Fidelity Advisor Risk Parity Fund - Class A | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 4.20%
Fidelity Advisor Risk Parity Fund - Class A | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.70%
Fidelity Advisor Risk Parity Fund - Class A | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.20%
Fidelity Advisor Risk Parity Fund - Class A | DEFuturesContractsMember  
Holdings [Line Items]  
Percent of Net Asset Value 15.00%
Fidelity Advisor Risk Parity Fund - Class A | DESwapsMember  
Holdings [Line Items]  
Percent of Net Asset Value 60.50%
Fidelity Advisor Risk Parity Fund - Class A | AASwapsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 34.50%
Fidelity Advisor Risk Parity Fund - Class A | AAFuturesContractsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 8.50%
Fidelity Advisor Risk Parity Fund - Class A | AADomesticEquityFundsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 21.00%
Fidelity Advisor Risk Parity Fund - Class A | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Long Exposure 4.90%
Fidelity Advisor Risk Parity Fund - Class A | AAFixedIncomeFundsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 27.30%
Fidelity Advisor Risk Parity Fund - Class A | AAInternationalEquityFundsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 3.80%
Fidelity Hedged Equity Fund | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 7.50%
Fidelity Hedged Equity Fund | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 7.00%
Fidelity Hedged Equity Fund | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 5.90%
Fidelity Hedged Equity Fund | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 5.60%
Fidelity Hedged Equity Fund | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 4.20%
Fidelity Hedged Equity Fund | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.90%
Fidelity Hedged Equity Fund | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.90%
Fidelity Hedged Equity Fund | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.90%
Fidelity Hedged Equity Fund | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.80%
Fidelity Hedged Equity Fund | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.80%
Fidelity Hedged Equity Fund | AACommonStocksMember  
Holdings [Line Items]  
Percent of Net Long Exposure 96.70%
Fidelity Hedged Equity Fund | AADomesticEquityFundsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 1.90%
Fidelity Hedged Equity Fund | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Long Exposure 0.40%
Fidelity Hedged Equity Fund | DEOptionsMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity Hedged Equity Fund | AAOptionsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 1.00%
Fidelity Advisor Hedged Equity Fund - Class Z | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 7.50%
Fidelity Advisor Hedged Equity Fund - Class Z | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 7.00%
Fidelity Advisor Hedged Equity Fund - Class Z | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 5.90%
Fidelity Advisor Hedged Equity Fund - Class Z | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 5.60%
Fidelity Advisor Hedged Equity Fund - Class Z | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 4.20%
Fidelity Advisor Hedged Equity Fund - Class Z | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.90%
Fidelity Advisor Hedged Equity Fund - Class Z | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.90%
Fidelity Advisor Hedged Equity Fund - Class Z | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.90%
Fidelity Advisor Hedged Equity Fund - Class Z | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.80%
Fidelity Advisor Hedged Equity Fund - Class Z | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.80%
Fidelity Advisor Hedged Equity Fund - Class Z | AACommonStocksMember  
Holdings [Line Items]  
Percent of Net Long Exposure 96.70%
Fidelity Advisor Hedged Equity Fund - Class Z | AADomesticEquityFundsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 1.90%
Fidelity Advisor Hedged Equity Fund - Class Z | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Long Exposure 0.40%
Fidelity Advisor Hedged Equity Fund - Class Z | DEOptionsMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity Advisor Hedged Equity Fund - Class Z | AAOptionsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 1.00%
Fidelity Advisor Hedged Equity Fund - Class M | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 7.50%
Fidelity Advisor Hedged Equity Fund - Class M | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 7.00%
Fidelity Advisor Hedged Equity Fund - Class M | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 5.90%
Fidelity Advisor Hedged Equity Fund - Class M | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 5.60%
Fidelity Advisor Hedged Equity Fund - Class M | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 4.20%
Fidelity Advisor Hedged Equity Fund - Class M | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.90%
Fidelity Advisor Hedged Equity Fund - Class M | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.90%
Fidelity Advisor Hedged Equity Fund - Class M | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.90%
Fidelity Advisor Hedged Equity Fund - Class M | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.80%
Fidelity Advisor Hedged Equity Fund - Class M | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.80%
Fidelity Advisor Hedged Equity Fund - Class M | AACommonStocksMember  
Holdings [Line Items]  
Percent of Net Long Exposure 96.70%
Fidelity Advisor Hedged Equity Fund - Class M | AADomesticEquityFundsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 1.90%
Fidelity Advisor Hedged Equity Fund - Class M | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Long Exposure 0.40%
Fidelity Advisor Hedged Equity Fund - Class M | DEOptionsMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity Advisor Hedged Equity Fund - Class M | AAOptionsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 1.00%
Fidelity Advisor Hedged Equity Fund - Class I | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 7.50%
Fidelity Advisor Hedged Equity Fund - Class I | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 7.00%
Fidelity Advisor Hedged Equity Fund - Class I | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 5.90%
Fidelity Advisor Hedged Equity Fund - Class I | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 5.60%
Fidelity Advisor Hedged Equity Fund - Class I | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 4.20%
Fidelity Advisor Hedged Equity Fund - Class I | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.90%
Fidelity Advisor Hedged Equity Fund - Class I | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.90%
Fidelity Advisor Hedged Equity Fund - Class I | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.90%
Fidelity Advisor Hedged Equity Fund - Class I | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.80%
Fidelity Advisor Hedged Equity Fund - Class I | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.80%
Fidelity Advisor Hedged Equity Fund - Class I | AACommonStocksMember  
Holdings [Line Items]  
Percent of Net Long Exposure 96.70%
Fidelity Advisor Hedged Equity Fund - Class I | AADomesticEquityFundsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 1.90%
Fidelity Advisor Hedged Equity Fund - Class I | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Long Exposure 0.40%
Fidelity Advisor Hedged Equity Fund - Class I | DEOptionsMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity Advisor Hedged Equity Fund - Class I | AAOptionsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 1.00%
Fidelity Advisor Hedged Equity Fund - Class C | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 7.50%
Fidelity Advisor Hedged Equity Fund - Class C | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 7.00%
Fidelity Advisor Hedged Equity Fund - Class C | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 5.90%
Fidelity Advisor Hedged Equity Fund - Class C | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 5.60%
Fidelity Advisor Hedged Equity Fund - Class C | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 4.20%
Fidelity Advisor Hedged Equity Fund - Class C | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.90%
Fidelity Advisor Hedged Equity Fund - Class C | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.90%
Fidelity Advisor Hedged Equity Fund - Class C | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.90%
Fidelity Advisor Hedged Equity Fund - Class C | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.80%
Fidelity Advisor Hedged Equity Fund - Class C | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.80%
Fidelity Advisor Hedged Equity Fund - Class C | AACommonStocksMember  
Holdings [Line Items]  
Percent of Net Long Exposure 96.70%
Fidelity Advisor Hedged Equity Fund - Class C | AADomesticEquityFundsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 1.90%
Fidelity Advisor Hedged Equity Fund - Class C | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Long Exposure 0.40%
Fidelity Advisor Hedged Equity Fund - Class C | DEOptionsMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity Advisor Hedged Equity Fund - Class C | AAOptionsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 1.00%
Fidelity Advisor Hedged Equity Fund - Class A | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 7.50%
Fidelity Advisor Hedged Equity Fund - Class A | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 7.00%
Fidelity Advisor Hedged Equity Fund - Class A | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 5.90%
Fidelity Advisor Hedged Equity Fund - Class A | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 5.60%
Fidelity Advisor Hedged Equity Fund - Class A | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 4.20%
Fidelity Advisor Hedged Equity Fund - Class A | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.90%
Fidelity Advisor Hedged Equity Fund - Class A | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.90%
Fidelity Advisor Hedged Equity Fund - Class A | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.90%
Fidelity Advisor Hedged Equity Fund - Class A | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.80%
Fidelity Advisor Hedged Equity Fund - Class A | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.80%
Fidelity Advisor Hedged Equity Fund - Class A | AACommonStocksMember  
Holdings [Line Items]  
Percent of Net Long Exposure 96.70%
Fidelity Advisor Hedged Equity Fund - Class A | AADomesticEquityFundsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 1.90%
Fidelity Advisor Hedged Equity Fund - Class A | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Long Exposure 0.40%
Fidelity Advisor Hedged Equity Fund - Class A | DEOptionsMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity Advisor Hedged Equity Fund - Class A | AAOptionsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 1.00%
Fidelity Equity Market Neutral Fund | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 5.10%
Fidelity Equity Market Neutral Fund | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.50%
Fidelity Equity Market Neutral Fund | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.40%
Fidelity Equity Market Neutral Fund | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.20%
Fidelity Equity Market Neutral Fund | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.20%
Fidelity Equity Market Neutral Fund | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.20%
Fidelity Equity Market Neutral Fund | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.10%
Fidelity Equity Market Neutral Fund | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.10%
Fidelity Equity Market Neutral Fund | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.10%
Fidelity Equity Market Neutral Fund | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.10%
Fidelity Equity Market Neutral Fund | DESwapsMember  
Holdings [Line Items]  
Percent of Net Asset Value 126.00%
Fidelity Equity Market Neutral Fund | AASwapsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 45.20%
Fidelity Equity Market Neutral Fund | AACommonStocksMember  
Holdings [Line Items]  
Percent of Net Long Exposure 34.60%
Fidelity Equity Market Neutral Fund | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Long Exposure 1.30%
Fidelity Equity Market Neutral Fund | DEForwardForeignCurrencyContractsMember  
Holdings [Line Items]  
Percent of Net Asset Value 52.60%
Fidelity Equity Market Neutral Fund | AAForwardForeignCurrencyContractsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 18.90%
Fidelity Advisor Equity Market Neutral Fund - Class A | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 5.10%
Fidelity Advisor Equity Market Neutral Fund - Class A | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.50%
Fidelity Advisor Equity Market Neutral Fund - Class A | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.40%
Fidelity Advisor Equity Market Neutral Fund - Class A | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.20%
Fidelity Advisor Equity Market Neutral Fund - Class A | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.20%
Fidelity Advisor Equity Market Neutral Fund - Class A | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.20%
Fidelity Advisor Equity Market Neutral Fund - Class A | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.10%
Fidelity Advisor Equity Market Neutral Fund - Class A | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.10%
Fidelity Advisor Equity Market Neutral Fund - Class A | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.10%
Fidelity Advisor Equity Market Neutral Fund - Class A | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.10%
Fidelity Advisor Equity Market Neutral Fund - Class A | DESwapsMember  
Holdings [Line Items]  
Percent of Net Asset Value 126.00%
Fidelity Advisor Equity Market Neutral Fund - Class A | AASwapsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 45.20%
Fidelity Advisor Equity Market Neutral Fund - Class A | AACommonStocksMember  
Holdings [Line Items]  
Percent of Net Long Exposure 34.60%
Fidelity Advisor Equity Market Neutral Fund - Class A | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Long Exposure 1.30%
Fidelity Advisor Equity Market Neutral Fund - Class A | DEForwardForeignCurrencyContractsMember  
Holdings [Line Items]  
Percent of Net Asset Value 52.60%
Fidelity Advisor Equity Market Neutral Fund - Class A | AAForwardForeignCurrencyContractsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 18.90%
Fidelity Advisor Equity Market Neutral Fund - Class M | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 5.10%
Fidelity Advisor Equity Market Neutral Fund - Class M | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.50%
Fidelity Advisor Equity Market Neutral Fund - Class M | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.40%
Fidelity Advisor Equity Market Neutral Fund - Class M | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.20%
Fidelity Advisor Equity Market Neutral Fund - Class M | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.20%
Fidelity Advisor Equity Market Neutral Fund - Class M | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.20%
Fidelity Advisor Equity Market Neutral Fund - Class M | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.10%
Fidelity Advisor Equity Market Neutral Fund - Class M | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.10%
Fidelity Advisor Equity Market Neutral Fund - Class M | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.10%
Fidelity Advisor Equity Market Neutral Fund - Class M | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.10%
Fidelity Advisor Equity Market Neutral Fund - Class M | DESwapsMember  
Holdings [Line Items]  
Percent of Net Asset Value 126.00%
Fidelity Advisor Equity Market Neutral Fund - Class M | AASwapsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 45.20%
Fidelity Advisor Equity Market Neutral Fund - Class M | AACommonStocksMember  
Holdings [Line Items]  
Percent of Net Long Exposure 34.60%
Fidelity Advisor Equity Market Neutral Fund - Class M | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Long Exposure 1.30%
Fidelity Advisor Equity Market Neutral Fund - Class M | DEForwardForeignCurrencyContractsMember  
Holdings [Line Items]  
Percent of Net Asset Value 52.60%
Fidelity Advisor Equity Market Neutral Fund - Class M | AAForwardForeignCurrencyContractsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 18.90%
Fidelity Advisor Equity Market Neutral Fund - Class C | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 5.10%
Fidelity Advisor Equity Market Neutral Fund - Class C | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.50%
Fidelity Advisor Equity Market Neutral Fund - Class C | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.40%
Fidelity Advisor Equity Market Neutral Fund - Class C | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.20%
Fidelity Advisor Equity Market Neutral Fund - Class C | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.20%
Fidelity Advisor Equity Market Neutral Fund - Class C | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.20%
Fidelity Advisor Equity Market Neutral Fund - Class C | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.10%
Fidelity Advisor Equity Market Neutral Fund - Class C | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.10%
Fidelity Advisor Equity Market Neutral Fund - Class C | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.10%
Fidelity Advisor Equity Market Neutral Fund - Class C | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.10%
Fidelity Advisor Equity Market Neutral Fund - Class C | DESwapsMember  
Holdings [Line Items]  
Percent of Net Asset Value 126.00%
Fidelity Advisor Equity Market Neutral Fund - Class C | AASwapsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 45.20%
Fidelity Advisor Equity Market Neutral Fund - Class C | AACommonStocksMember  
Holdings [Line Items]  
Percent of Net Long Exposure 34.60%
Fidelity Advisor Equity Market Neutral Fund - Class C | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Long Exposure 1.30%
Fidelity Advisor Equity Market Neutral Fund - Class C | DEForwardForeignCurrencyContractsMember  
Holdings [Line Items]  
Percent of Net Asset Value 52.60%
Fidelity Advisor Equity Market Neutral Fund - Class C | AAForwardForeignCurrencyContractsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 18.90%
Fidelity Advisor Equity Market Neutral Fund - Class I | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 5.10%
Fidelity Advisor Equity Market Neutral Fund - Class I | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.50%
Fidelity Advisor Equity Market Neutral Fund - Class I | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.40%
Fidelity Advisor Equity Market Neutral Fund - Class I | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.20%
Fidelity Advisor Equity Market Neutral Fund - Class I | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.20%
Fidelity Advisor Equity Market Neutral Fund - Class I | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.20%
Fidelity Advisor Equity Market Neutral Fund - Class I | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.10%
Fidelity Advisor Equity Market Neutral Fund - Class I | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.10%
Fidelity Advisor Equity Market Neutral Fund - Class I | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.10%
Fidelity Advisor Equity Market Neutral Fund - Class I | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.10%
Fidelity Advisor Equity Market Neutral Fund - Class I | DESwapsMember  
Holdings [Line Items]  
Percent of Net Asset Value 126.00%
Fidelity Advisor Equity Market Neutral Fund - Class I | AASwapsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 45.20%
Fidelity Advisor Equity Market Neutral Fund - Class I | AACommonStocksMember  
Holdings [Line Items]  
Percent of Net Long Exposure 34.60%
Fidelity Advisor Equity Market Neutral Fund - Class I | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Long Exposure 1.30%
Fidelity Advisor Equity Market Neutral Fund - Class I | DEForwardForeignCurrencyContractsMember  
Holdings [Line Items]  
Percent of Net Asset Value 52.60%
Fidelity Advisor Equity Market Neutral Fund - Class I | AAForwardForeignCurrencyContractsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 18.90%
Fidelity Advisor Equity Market Neutral Fund - Class Z | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 5.10%
Fidelity Advisor Equity Market Neutral Fund - Class Z | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.50%
Fidelity Advisor Equity Market Neutral Fund - Class Z | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.40%
Fidelity Advisor Equity Market Neutral Fund - Class Z | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.20%
Fidelity Advisor Equity Market Neutral Fund - Class Z | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.20%
Fidelity Advisor Equity Market Neutral Fund - Class Z | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.20%
Fidelity Advisor Equity Market Neutral Fund - Class Z | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.10%
Fidelity Advisor Equity Market Neutral Fund - Class Z | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.10%
Fidelity Advisor Equity Market Neutral Fund - Class Z | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.10%
Fidelity Advisor Equity Market Neutral Fund - Class Z | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.10%
Fidelity Advisor Equity Market Neutral Fund - Class Z | DESwapsMember  
Holdings [Line Items]  
Percent of Net Asset Value 126.00%
Fidelity Advisor Equity Market Neutral Fund - Class Z | AASwapsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 45.20%
Fidelity Advisor Equity Market Neutral Fund - Class Z | AACommonStocksMember  
Holdings [Line Items]  
Percent of Net Long Exposure 34.60%
Fidelity Advisor Equity Market Neutral Fund - Class Z | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Long Exposure 1.30%
Fidelity Advisor Equity Market Neutral Fund - Class Z | DEForwardForeignCurrencyContractsMember  
Holdings [Line Items]  
Percent of Net Asset Value 52.60%
Fidelity Advisor Equity Market Neutral Fund - Class Z | AAForwardForeignCurrencyContractsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 18.90%
Fidelity Yield Enhanced Equity ETF | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 7.80%
Fidelity Yield Enhanced Equity ETF | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 7.30%
Fidelity Yield Enhanced Equity ETF | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 5.10%
Fidelity Yield Enhanced Equity ETF | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 4.20%
Fidelity Yield Enhanced Equity ETF | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.70%
Fidelity Yield Enhanced Equity ETF | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.00%
Fidelity Yield Enhanced Equity ETF | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.10%
Fidelity Yield Enhanced Equity ETF | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.10%
Fidelity Yield Enhanced Equity ETF | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.00%
Fidelity Yield Enhanced Equity ETF | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.90%
Fidelity Yield Enhanced Equity ETF | DEFuturesContractsMember  
Holdings [Line Items]  
Percent of Net Asset Value 2.20%
Fidelity Yield Enhanced Equity ETF | AACommonStocksMember  
Holdings [Line Items]  
Percent of Net Long Exposure 95.60%
Fidelity Yield Enhanced Equity ETF | AAFuturesContractsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 2.10%
Fidelity Yield Enhanced Equity ETF | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Long Exposure 2.60%
Fidelity Yield Enhanced Equity ETF | DEOptionsMember  
Holdings [Line Items]  
Percent of Net Asset Value (0.40%)
Fidelity Dynamic Buffered Equity ETF | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 7.80%
Fidelity Dynamic Buffered Equity ETF | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 7.30%
Fidelity Dynamic Buffered Equity ETF | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 4.90%
Fidelity Dynamic Buffered Equity ETF | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 4.30%
Fidelity Dynamic Buffered Equity ETF | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.60%
Fidelity Dynamic Buffered Equity ETF | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.00%
Fidelity Dynamic Buffered Equity ETF | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.40%
Fidelity Dynamic Buffered Equity ETF | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.00%
Fidelity Dynamic Buffered Equity ETF | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.00%
Fidelity Dynamic Buffered Equity ETF | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.90%
Fidelity Dynamic Buffered Equity ETF | DEFuturesContractsMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.30%
Fidelity Dynamic Buffered Equity ETF | AACommonStocksMember  
Holdings [Line Items]  
Percent of Net Long Exposure 97.00%
Fidelity Dynamic Buffered Equity ETF | AAFuturesContractsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 1.20%
Fidelity Dynamic Buffered Equity ETF | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Long Exposure 1.70%
Fidelity Dynamic Buffered Equity ETF | DEOptionsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.00%
Fidelity Dynamic Buffered Equity ETF | AAOptionsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 0.10%
Fidelity Hedged Equity ETF | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 7.80%
Fidelity Hedged Equity ETF | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 7.30%
Fidelity Hedged Equity ETF | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 5.20%
Fidelity Hedged Equity ETF | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 4.20%
Fidelity Hedged Equity ETF | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.40%
Fidelity Hedged Equity ETF | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.90%
Fidelity Hedged Equity ETF | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.50%
Fidelity Hedged Equity ETF | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.00%
Fidelity Hedged Equity ETF | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.00%
Fidelity Hedged Equity ETF | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.90%
Fidelity Hedged Equity ETF | DEFuturesContractsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.60%
Fidelity Hedged Equity ETF | AACommonStocksMember  
Holdings [Line Items]  
Percent of Net Long Exposure 97.00%
Fidelity Hedged Equity ETF | AAFuturesContractsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 0.60%
Fidelity Hedged Equity ETF | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Long Exposure 1.40%
Fidelity Hedged Equity ETF | DEOptionsMember  
Holdings [Line Items]  
Percent of Net Asset Value 1.00%
Fidelity Hedged Equity ETF | AAOptionsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 1.00%
Fidelity Managed Futures ETF | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 49.60%
Fidelity Managed Futures ETF | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 3.80%
Fidelity Managed Futures ETF | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 2.10%
Fidelity Managed Futures ETF | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.80%
Fidelity Managed Futures ETF | DEFuturesContractsMember  
Holdings [Line Items]  
Percent of Net Asset Value 850.90%
Fidelity Managed Futures ETF | DESwapsMember  
Holdings [Line Items]  
Percent of Net Asset Value 199.40%
Fidelity Managed Futures ETF | AASwapsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 13.20%
Fidelity Managed Futures ETF | AACommonStocksMember  
Holdings [Line Items]  
Percent of Net Long Exposure 0.20%
Fidelity Managed Futures ETF | AAFuturesContractsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 56.70%
Fidelity Managed Futures ETF | AADomesticEquityFundsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 0.30%
Fidelity Managed Futures ETF | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Long Exposure 6.20%
Fidelity Managed Futures ETF | DEForwardForeignCurrencyContractsMember  
Holdings [Line Items]  
Percent of Net Asset Value 351.70%
Fidelity Managed Futures ETF | AAForwardForeignCurrencyContractsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 23.40%
Fidelity SAI Merger Arbitrage Fund | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 15.10%
Fidelity SAI Merger Arbitrage Fund | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 12.30%
Fidelity SAI Merger Arbitrage Fund | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 9.80%
Fidelity SAI Merger Arbitrage Fund | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 9.00%
Fidelity SAI Merger Arbitrage Fund | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 8.20%
Fidelity SAI Merger Arbitrage Fund | TH5Member  
Holdings [Line Items]  
Percent of Net Asset Value 7.90%
Fidelity SAI Merger Arbitrage Fund | TH6Member  
Holdings [Line Items]  
Percent of Net Asset Value 5.00%
Fidelity SAI Merger Arbitrage Fund | TH7Member  
Holdings [Line Items]  
Percent of Net Asset Value 5.00%
Fidelity SAI Merger Arbitrage Fund | TH8Member  
Holdings [Line Items]  
Percent of Net Asset Value 4.30%
Fidelity SAI Merger Arbitrage Fund | TH9Member  
Holdings [Line Items]  
Percent of Net Asset Value 4.20%
Fidelity SAI Merger Arbitrage Fund | DESwapsMember  
Holdings [Line Items]  
Percent of Net Asset Value 60.30%
Fidelity SAI Merger Arbitrage Fund | AASwapsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 37.60%
Fidelity SAI Merger Arbitrage Fund | AACommonStocksMember  
Holdings [Line Items]  
Percent of Net Long Exposure 54.70%
Fidelity SAI Merger Arbitrage Fund | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Long Exposure 7.70%
Fidelity SAI Merger Arbitrage Fund | DEOptionsMember  
Holdings [Line Items]  
Percent of Net Asset Value 0.20%
Fidelity SAI Merger Arbitrage Fund | AAOptionsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 0.00%
Fidelity SAI Managed Futures Fund | TH0Member  
Holdings [Line Items]  
Percent of Net Asset Value 50.50%
Fidelity SAI Managed Futures Fund | TH1Member  
Holdings [Line Items]  
Percent of Net Asset Value 4.40%
Fidelity SAI Managed Futures Fund | TH2Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.40%
Fidelity SAI Managed Futures Fund | TH3Member  
Holdings [Line Items]  
Percent of Net Asset Value 1.10%
Fidelity SAI Managed Futures Fund | TH4Member  
Holdings [Line Items]  
Percent of Net Asset Value 0.90%
Fidelity SAI Managed Futures Fund | DEFuturesContractsMember  
Holdings [Line Items]  
Percent of Net Asset Value 841.60%
Fidelity SAI Managed Futures Fund | DESwapsMember  
Holdings [Line Items]  
Percent of Net Asset Value 152.60%
Fidelity SAI Managed Futures Fund | AASwapsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 10.90%
Fidelity SAI Managed Futures Fund | AACommonStocksMember  
Holdings [Line Items]  
Percent of Net Long Exposure 0.10%
Fidelity SAI Managed Futures Fund | AAFuturesContractsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 60.40%
Fidelity SAI Managed Futures Fund | AADomesticEquityFundsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 0.40%
Fidelity SAI Managed Futures Fund | AAShortTermInvestmentsandNetOtherAssetsLiabilitiesMember  
Holdings [Line Items]  
Percent of Net Long Exposure 6.60%
Fidelity SAI Managed Futures Fund | DEForwardForeignCurrencyContractsMember  
Holdings [Line Items]  
Percent of Net Asset Value 300.40%
Fidelity SAI Managed Futures Fund | AAForwardForeignCurrencyContractsMember  
Holdings [Line Items]  
Percent of Net Long Exposure 21.60%