v3.26.3
Shareholder Report
 6 Months Ended
Jul. 31, 2026
USD ($)
shares
Shareholder Report [Line Items]  
Document Type N-CSRS
Amendment Flag false
Registrant Name Fidelity Greenwood Street Trust
Entity Central Index Key 0001898391
Entity Investment Company Type N-1A
Document Period End Date Jul. 31, 2026
Fidelity SAI Convertible Arbitrage Fund  
Shareholder Report [Line Items]  
Fund Name Fidelity® SAI Convertible Arbitrage Fund
Class Name Fidelity® SAI Convertible Arbitrage Fund
Trading Symbol FSAWX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains information about Fidelity® SAI Convertible Arbitrage Fund for the period February 1, 2026 to July 31, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-800-544-3455 or by sending an e-mail to fidfunddocuments@fidelity.com.
Additional Information Phone Number 1-800-544-3455
Additional Information Email fidfunddocuments@fidelity.com
Additional Information Website fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block] What were your Fund costs for the last six months?
(based on hypothetical $10,000 investment)
 
 
 
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
 
Fidelity® SAI Convertible Arbitrage Fund 
$ 74 
1.45%
  
Expenses Paid, Amount $ 74
Expense Ratio, Percent 1.45%
Net Assets $ 1,272,626,272
Holdings Count | shares 51
Investment Company Portfolio Turnover 456.00%
Additional Fund Statistics [Text Block] Key Fund Statistics
(as of July 31, 2026)
 
KEY FACTS 
  
  
Fund Size
$1,272,626,272
  
Number of Holdings
51
  
Portfolio Turnover
456%
  
Holdings [Text Block] DERIVATIVE EXPOSURE (% of Fund's net assets)     Futures Contracts 22.1   Swaps 390.0           Swaps 76.2 Corporate Bonds 7.2 Common Stocks 5.6 U.S. Treasury Obligations 5.6 Futures Contracts 4.3 Domestic Equity Funds 0.3 Short-Term Investments and Net Other Assets (Liabilities) 0.8 ASSET ALLOCATION (% of Fund's total exposure)     Swaps - 76.2                               Corporate Bonds - 7.2                      Common Stocks - 5.6                        U.S. Treasury Obligations - 5.6            Futures Contracts - 4.3                    Domestic Equity Funds - 0.3                Short-Term Investments and Net Other Assets (Liabilities) - 0.8  
Largest Holdings [Text Block] TOP HOLDINGS(% of Fund's net assets)     US Treasury Bill 28.5   Mastercard Inc Class A 8.5   Philip Morris International Inc 6.7   Western Digital Corp 3.6   Knight-Swift Transportation Holdings Inc 3.5   Citigroup Inc 3.4   LCI Industries 3.4   Microsoft Corp 3.2   NVIDIA Corp 2.5   Pitney Bowes Inc 2.4     65.7  
Fidelity Risk Parity Fund  
Shareholder Report [Line Items]  
Fund Name Fidelity® Risk Parity Fund
Class Name Fidelity® Risk Parity Fund
Trading Symbol FAPSX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains information about Fidelity® Risk Parity Fund for the period February 1, 2026 to July 31, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-800-544-8544 or by sending an e-mail to fidfunddocuments@fidelity.com.
Additional Information Phone Number 1-800-544-8544
Additional Information Email fidfunddocuments@fidelity.com
Additional Information Website fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block] What were your Fund costs for the last six months?
(based on hypothetical $10,000 investment)
 
 
 
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
 
Fidelity® Risk Parity Fund 
$ 30 
0.60%
  
Expenses Paid, Amount $ 30
Expense Ratio, Percent 0.60%
Net Assets $ 15,735,719
Holdings Count | shares 33
Investment Company Portfolio Turnover 104.00%
Additional Fund Statistics [Text Block] Key Fund Statistics
(as of July 31, 2026)
 
KEY FACTS 
  
  
Fund Size
$15,735,719
  
Number of Holdings
33
  
Portfolio Turnover
104%
  
Holdings [Text Block] DERIVATIVE EXPOSURE (% of Fund's net assets)     Futures Contracts 15.0   Swaps 60.5           Swaps 34.5 Fixed-Income Funds 27.3 Domestic Equity Funds 21.0 Futures Contracts 8.5 International Equity Funds 3.8 Short-Term Investments and Net Other Assets (Liabilities) 4.9 ASSET ALLOCATION (% of Fund's total exposure)     Swaps - 34.5                               Fixed-Income Funds - 27.3                  Domestic Equity Funds - 21.0               Futures Contracts - 8.5                    International Equity Funds - 3.8           Short-Term Investments and Net Other Assets (Liabilities) - 4.9  
Largest Holdings [Text Block] TOP HOLDINGS(% of Fund's net assets)     Fidelity Inflation-Protected Bond Index Fund 24.0   Fidelity Commodity Strategy Fund 15.9   iShares US Treasury Bond ETF 11.2   Fidelity Small Cap Value Index Fund 8.2   iShares J.P. Morgan EM Local Currency Bond ETF 7.7   Fidelity Small Cap Index Fund 5.4   US Treasury Bill 5.2   Fidelity International Index Fund 4.2   Fidelity Real Estate Index Fund 3.7   Fidelity Long-Term Treasury Bond Index Fund 3.2     88.7  
Fidelity Advisor Risk Parity Fund - Class Z  
Shareholder Report [Line Items]  
Fund Name Fidelity® Risk Parity Fund
Class Name Fidelity Advisor® Risk Parity Fund Class Z
Trading Symbol FAPZX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains information about Fidelity® Risk Parity Fund for the period February 1, 2026 to July 31, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-877-208-0098 or by sending an e-mail to fidfunddocuments@fidelity.com.
Additional Information Phone Number 1-877-208-0098
Additional Information Email fidfunddocuments@fidelity.com
Additional Information Website fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block] What were your Fund costs for the last six months?
(based on hypothetical $10,000 investment)
 
 
 
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
 
Class Z 
$ 28 
0.55%
  
Expenses Paid, Amount $ 28
Expense Ratio, Percent 0.55%
Net Assets $ 15,735,719
Holdings Count | shares 33
Investment Company Portfolio Turnover 104.00%
Additional Fund Statistics [Text Block] Key Fund Statistics
(as of July 31, 2026)
 
KEY FACTS 
  
  
Fund Size
$15,735,719
  
Number of Holdings
33
  
Portfolio Turnover
104%
  
Holdings [Text Block] DERIVATIVE EXPOSURE (% of Fund's net assets)     Futures Contracts 15.0   Swaps 60.5           Swaps 34.5 Fixed-Income Funds 27.3 Domestic Equity Funds 21.0 Futures Contracts 8.5 International Equity Funds 3.8 Short-Term Investments and Net Other Assets (Liabilities) 4.9 ASSET ALLOCATION (% of Fund's total exposure)     Swaps - 34.5                               Fixed-Income Funds - 27.3                  Domestic Equity Funds - 21.0               Futures Contracts - 8.5                    International Equity Funds - 3.8           Short-Term Investments and Net Other Assets (Liabilities) - 4.9  
Largest Holdings [Text Block] TOP HOLDINGS(% of Fund's net assets)     Fidelity Inflation-Protected Bond Index Fund 24.0   Fidelity Commodity Strategy Fund 15.9   iShares US Treasury Bond ETF 11.2   Fidelity Small Cap Value Index Fund 8.2   iShares J.P. Morgan EM Local Currency Bond ETF 7.7   Fidelity Small Cap Index Fund 5.4   US Treasury Bill 5.2   Fidelity International Index Fund 4.2   Fidelity Real Estate Index Fund 3.7   Fidelity Long-Term Treasury Bond Index Fund 3.2     88.7  
Fidelity Advisor Risk Parity Fund - Class M  
Shareholder Report [Line Items]  
Fund Name Fidelity® Risk Parity Fund
Class Name Fidelity Advisor® Risk Parity Fund Class M
Trading Symbol FAPWX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains information about Fidelity® Risk Parity Fund for the period February 1, 2026 to July 31, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-877-208-0098 or by sending an e-mail to fidfunddocuments@fidelity.com.
Additional Information Phone Number 1-877-208-0098
Additional Information Email fidfunddocuments@fidelity.com
Additional Information Website fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block] What were your Fund costs for the last six months?
(based on hypothetical $10,000 investment)
 
 
 
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
 
Class M 
$ 56 
1.10%
  
Expenses Paid, Amount $ 56
Expense Ratio, Percent 1.10%
Net Assets $ 15,735,719
Holdings Count | shares 33
Investment Company Portfolio Turnover 104.00%
Additional Fund Statistics [Text Block] Key Fund Statistics
(as of July 31, 2026)
 
KEY FACTS 
  
  
Fund Size
$15,735,719
  
Number of Holdings
33
  
Portfolio Turnover
104%
  
Holdings [Text Block] DERIVATIVE EXPOSURE (% of Fund's net assets)     Futures Contracts 15.0   Swaps 60.5           Swaps 34.5 Fixed-Income Funds 27.3 Domestic Equity Funds 21.0 Futures Contracts 8.5 International Equity Funds 3.8 Short-Term Investments and Net Other Assets (Liabilities) 4.9 ASSET ALLOCATION (% of Fund's total exposure)     Swaps - 34.5                               Fixed-Income Funds - 27.3                  Domestic Equity Funds - 21.0               Futures Contracts - 8.5                    International Equity Funds - 3.8           Short-Term Investments and Net Other Assets (Liabilities) - 4.9  
Largest Holdings [Text Block] TOP HOLDINGS(% of Fund's net assets)     Fidelity Inflation-Protected Bond Index Fund 24.0   Fidelity Commodity Strategy Fund 15.9   iShares US Treasury Bond ETF 11.2   Fidelity Small Cap Value Index Fund 8.2   iShares J.P. Morgan EM Local Currency Bond ETF 7.7   Fidelity Small Cap Index Fund 5.4   US Treasury Bill 5.2   Fidelity International Index Fund 4.2   Fidelity Real Estate Index Fund 3.7   Fidelity Long-Term Treasury Bond Index Fund 3.2     88.7  
Fidelity Advisor Risk Parity Fund - Class I  
Shareholder Report [Line Items]  
Fund Name Fidelity® Risk Parity Fund
Class Name Fidelity Advisor® Risk Parity Fund Class I
Trading Symbol FAPYX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains information about Fidelity® Risk Parity Fund for the period February 1, 2026 to July 31, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-877-208-0098 or by sending an e-mail to fidfunddocuments@fidelity.com.
Additional Information Phone Number 1-877-208-0098
Additional Information Email fidfunddocuments@fidelity.com
Additional Information Website fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block] What were your Fund costs for the last six months?
(based on hypothetical $10,000 investment)
 
 
 
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
 
Class I 
$ 30 
0.60%
  
Expenses Paid, Amount $ 30
Expense Ratio, Percent 0.60%
Net Assets $ 15,735,719
Holdings Count | shares 33
Investment Company Portfolio Turnover 104.00%
Additional Fund Statistics [Text Block] Key Fund Statistics
(as of July 31, 2026)
 
KEY FACTS 
  
  
Fund Size
$15,735,719
  
Number of Holdings
33
  
Portfolio Turnover
104%
  
Holdings [Text Block] DERIVATIVE EXPOSURE (% of Fund's net assets)     Futures Contracts 15.0   Swaps 60.5           Swaps 34.5 Fixed-Income Funds 27.3 Domestic Equity Funds 21.0 Futures Contracts 8.5 International Equity Funds 3.8 Short-Term Investments and Net Other Assets (Liabilities) 4.9 ASSET ALLOCATION (% of Fund's total exposure)     Swaps - 34.5                               Fixed-Income Funds - 27.3                  Domestic Equity Funds - 21.0               Futures Contracts - 8.5                    International Equity Funds - 3.8           Short-Term Investments and Net Other Assets (Liabilities) - 4.9  
Largest Holdings [Text Block] TOP HOLDINGS(% of Fund's net assets)     Fidelity Inflation-Protected Bond Index Fund 24.0   Fidelity Commodity Strategy Fund 15.9   iShares US Treasury Bond ETF 11.2   Fidelity Small Cap Value Index Fund 8.2   iShares J.P. Morgan EM Local Currency Bond ETF 7.7   Fidelity Small Cap Index Fund 5.4   US Treasury Bill 5.2   Fidelity International Index Fund 4.2   Fidelity Real Estate Index Fund 3.7   Fidelity Long-Term Treasury Bond Index Fund 3.2     88.7  
Fidelity Advisor Risk Parity Fund - Class C  
Shareholder Report [Line Items]  
Fund Name Fidelity® Risk Parity Fund
Class Name Fidelity Advisor® Risk Parity Fund Class C
Trading Symbol FAPVX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains information about Fidelity® Risk Parity Fund for the period February 1, 2026 to July 31, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-877-208-0098 or by sending an e-mail to fidfunddocuments@fidelity.com.
Additional Information Phone Number 1-877-208-0098
Additional Information Email fidfunddocuments@fidelity.com
Additional Information Website fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block] What were your Fund costs for the last six months?
(based on hypothetical $10,000 investment)
 
 
 
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
 
Class C 
$ 81 
1.60%
  
Expenses Paid, Amount $ 81
Expense Ratio, Percent 1.60%
Net Assets $ 15,735,719
Holdings Count | shares 33
Investment Company Portfolio Turnover 104.00%
Additional Fund Statistics [Text Block] Key Fund Statistics
(as of July 31, 2026)
 
KEY FACTS 
  
  
Fund Size
$15,735,719
  
Number of Holdings
33
  
Portfolio Turnover
104%
  
Holdings [Text Block] DERIVATIVE EXPOSURE (% of Fund's net assets)     Futures Contracts 15.0   Swaps 60.5           Swaps 34.5 Fixed-Income Funds 27.3 Domestic Equity Funds 21.0 Futures Contracts 8.5 International Equity Funds 3.8 Short-Term Investments and Net Other Assets (Liabilities) 4.9 ASSET ALLOCATION (% of Fund's total exposure)     Swaps - 34.5                               Fixed-Income Funds - 27.3                  Domestic Equity Funds - 21.0               Futures Contracts - 8.5                    International Equity Funds - 3.8           Short-Term Investments and Net Other Assets (Liabilities) - 4.9  
Largest Holdings [Text Block] TOP HOLDINGS(% of Fund's net assets)     Fidelity Inflation-Protected Bond Index Fund 24.0   Fidelity Commodity Strategy Fund 15.9   iShares US Treasury Bond ETF 11.2   Fidelity Small Cap Value Index Fund 8.2   iShares J.P. Morgan EM Local Currency Bond ETF 7.7   Fidelity Small Cap Index Fund 5.4   US Treasury Bill 5.2   Fidelity International Index Fund 4.2   Fidelity Real Estate Index Fund 3.7   Fidelity Long-Term Treasury Bond Index Fund 3.2     88.7  
Fidelity Advisor Risk Parity Fund - Class A  
Shareholder Report [Line Items]  
Fund Name Fidelity® Risk Parity Fund
Class Name Fidelity Advisor® Risk Parity Fund Class A
Trading Symbol FAPUX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains information about Fidelity® Risk Parity Fund for the period February 1, 2026 to July 31, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-877-208-0098 or by sending an e-mail to fidfunddocuments@fidelity.com.
Additional Information Phone Number 1-877-208-0098
Additional Information Email fidfunddocuments@fidelity.com
Additional Information Website fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block] What were your Fund costs for the last six months?
(based on hypothetical $10,000 investment)
 
 
 
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
 
Class A 
$ 43 
0.85%
  
Expenses Paid, Amount $ 43
Expense Ratio, Percent 0.85%
Net Assets $ 15,735,719
Holdings Count | shares 33
Investment Company Portfolio Turnover 104.00%
Additional Fund Statistics [Text Block] Key Fund Statistics
(as of July 31, 2026)
 
KEY FACTS 
  
  
Fund Size
$15,735,719
  
Number of Holdings
33
  
Portfolio Turnover
104%
  
Holdings [Text Block] DERIVATIVE EXPOSURE (% of Fund's net assets)     Futures Contracts 15.0   Swaps 60.5           Swaps 34.5 Fixed-Income Funds 27.3 Domestic Equity Funds 21.0 Futures Contracts 8.5 International Equity Funds 3.8 Short-Term Investments and Net Other Assets (Liabilities) 4.9 ASSET ALLOCATION (% of Fund's total exposure)     Swaps - 34.5                               Fixed-Income Funds - 27.3                  Domestic Equity Funds - 21.0               Futures Contracts - 8.5                    International Equity Funds - 3.8           Short-Term Investments and Net Other Assets (Liabilities) - 4.9  
Largest Holdings [Text Block] TOP HOLDINGS(% of Fund's net assets)     Fidelity Inflation-Protected Bond Index Fund 24.0   Fidelity Commodity Strategy Fund 15.9   iShares US Treasury Bond ETF 11.2   Fidelity Small Cap Value Index Fund 8.2   iShares J.P. Morgan EM Local Currency Bond ETF 7.7   Fidelity Small Cap Index Fund 5.4   US Treasury Bill 5.2   Fidelity International Index Fund 4.2   Fidelity Real Estate Index Fund 3.7   Fidelity Long-Term Treasury Bond Index Fund 3.2     88.7  
Fidelity Hedged Equity Fund  
Shareholder Report [Line Items]  
Fund Name Fidelity® Hedged Equity Fund
Class Name Fidelity® Hedged Equity Fund
Trading Symbol FEQHX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains information about Fidelity® Hedged Equity Fund for the period February 1, 2026 to July 31, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-800-544-8544 or by sending an e-mail to fidfunddocuments@fidelity.com.
Additional Information Phone Number 1-800-544-8544
Additional Information Email fidfunddocuments@fidelity.com
Additional Information Website fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block] What were your Fund costs for the last six months?
(based on hypothetical $10,000 investment)
 
 
 
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
 
Fidelity® Hedged Equity Fund 
$ 28 
0.55%
  
Expenses Paid, Amount $ 28
Expense Ratio, Percent 0.55%
Net Assets $ 768,208,152
Holdings Count | shares 464
Investment Company Portfolio Turnover 98.00%
Additional Fund Statistics [Text Block] Key Fund Statistics
(as of July 31, 2026)
 
KEY FACTS 
  
  
Fund Size
$768,208,152
  
Number of Holdings
464
  
Portfolio Turnover
98%
  
Holdings [Text Block] DERIVATIVE EXPOSURE (% of Fund's net assets)     Options 1.0           Common Stocks 96.7 Domestic Equity Funds 1.9 Options 1.0 Short-Term Investments and Net Other Assets (Liabilities) 0.4 ASSET ALLOCATION (% of Fund's total exposure)     Common Stocks - 96.7                       Domestic Equity Funds - 1.9                Options - 1.0                              Short-Term Investments and Net Other Assets (Liabilities) - 0.4  
Largest Holdings [Text Block] TOP HOLDINGS(% of Fund's net assets)     NVIDIA Corp 7.5   Apple Inc 7.0   Alphabet Inc Class A 5.9   Microsoft Corp 5.6   Amazon.com Inc 4.2   Broadcom Inc 2.9   Meta Platforms Inc Class A 1.9   iShares Core S&P 500 ETF 1.9   Berkshire Hathaway Inc Class B 1.8   JPMorgan Chase & Co 1.8     40.5  
Fidelity Advisor Hedged Equity Fund - Class Z  
Shareholder Report [Line Items]  
Fund Name Fidelity® Hedged Equity Fund
Class Name Fidelity Advisor® Hedged Equity Fund Class Z
Trading Symbol FEQZX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains information about Fidelity® Hedged Equity Fund for the period February 1, 2026 to July 31, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-877-208-0098 or by sending an e-mail to fidfunddocuments@fidelity.com.
Additional Information Phone Number 1-877-208-0098
Additional Information Email fidfunddocuments@fidelity.com
Additional Information Website fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block] What were your Fund costs for the last six months?
(based on hypothetical $10,000 investment)
 
 
 
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
 
Class Z 
$ 26 
0.50%
  
Expenses Paid, Amount $ 26
Expense Ratio, Percent 0.50%
Net Assets $ 768,208,152
Holdings Count | shares 464
Investment Company Portfolio Turnover 98.00%
Additional Fund Statistics [Text Block] Key Fund Statistics
(as of July 31, 2026)
 
KEY FACTS 
  
  
Fund Size
$768,208,152
  
Number of Holdings
464
  
Portfolio Turnover
98%
  
Holdings [Text Block] DERIVATIVE EXPOSURE (% of Fund's net assets)     Options 1.0           Common Stocks 96.7 Domestic Equity Funds 1.9 Options 1.0 Short-Term Investments and Net Other Assets (Liabilities) 0.4 ASSET ALLOCATION (% of Fund's total exposure)     Common Stocks - 96.7                       Domestic Equity Funds - 1.9                Options - 1.0                              Short-Term Investments and Net Other Assets (Liabilities) - 0.4  
Largest Holdings [Text Block] TOP HOLDINGS(% of Fund's net assets)     NVIDIA Corp 7.5   Apple Inc 7.0   Alphabet Inc Class A 5.9   Microsoft Corp 5.6   Amazon.com Inc 4.2   Broadcom Inc 2.9   Meta Platforms Inc Class A 1.9   iShares Core S&P 500 ETF 1.9   Berkshire Hathaway Inc Class B 1.8   JPMorgan Chase & Co 1.8     40.5  
Fidelity Advisor Hedged Equity Fund - Class M  
Shareholder Report [Line Items]  
Fund Name Fidelity® Hedged Equity Fund
Class Name Fidelity Advisor® Hedged Equity Fund Class M
Trading Symbol FEQNX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains information about Fidelity® Hedged Equity Fund for the period February 1, 2026 to July 31, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-877-208-0098 or by sending an e-mail to fidfunddocuments@fidelity.com.
Additional Information Phone Number 1-877-208-0098
Additional Information Email fidfunddocuments@fidelity.com
Additional Information Website fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block] What were your Fund costs for the last six months?
(based on hypothetical $10,000 investment)
 
 
 
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
 
Class M 
$ 54 
1.05%
  
Expenses Paid, Amount $ 54
Expense Ratio, Percent 1.05%
Net Assets $ 768,208,152
Holdings Count | shares 464
Investment Company Portfolio Turnover 98.00%
Additional Fund Statistics [Text Block] Key Fund Statistics
(as of July 31, 2026)
 
KEY FACTS 
  
  
Fund Size
$768,208,152
  
Number of Holdings
464
  
Portfolio Turnover
98%
  
Holdings [Text Block] DERIVATIVE EXPOSURE (% of Fund's net assets)     Options 1.0           Common Stocks 96.7 Domestic Equity Funds 1.9 Options 1.0 Short-Term Investments and Net Other Assets (Liabilities) 0.4 ASSET ALLOCATION (% of Fund's total exposure)     Common Stocks - 96.7                       Domestic Equity Funds - 1.9                Options - 1.0                              Short-Term Investments and Net Other Assets (Liabilities) - 0.4  
Largest Holdings [Text Block] TOP HOLDINGS(% of Fund's net assets)     NVIDIA Corp 7.5   Apple Inc 7.0   Alphabet Inc Class A 5.9   Microsoft Corp 5.6   Amazon.com Inc 4.2   Broadcom Inc 2.9   Meta Platforms Inc Class A 1.9   iShares Core S&P 500 ETF 1.9   Berkshire Hathaway Inc Class B 1.8   JPMorgan Chase & Co 1.8     40.5  
Fidelity Advisor Hedged Equity Fund - Class I  
Shareholder Report [Line Items]  
Fund Name Fidelity® Hedged Equity Fund
Class Name Fidelity Advisor® Hedged Equity Fund Class I
Trading Symbol FEQJX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains information about Fidelity® Hedged Equity Fund for the period February 1, 2026 to July 31, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-877-208-0098 or by sending an e-mail to fidfunddocuments@fidelity.com.
Additional Information Phone Number 1-877-208-0098
Additional Information Email fidfunddocuments@fidelity.com
Additional Information Website fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block] What were your Fund costs for the last six months?
(based on hypothetical $10,000 investment)
 
 
 
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
 
Class I 
$ 28 
0.55%
  
Expenses Paid, Amount $ 28
Expense Ratio, Percent 0.55%
Net Assets $ 768,208,152
Holdings Count | shares 464
Investment Company Portfolio Turnover 98.00%
Additional Fund Statistics [Text Block] Key Fund Statistics
(as of July 31, 2026)
 
KEY FACTS 
  
  
Fund Size
$768,208,152
  
Number of Holdings
464
  
Portfolio Turnover
98%
  
Holdings [Text Block] DERIVATIVE EXPOSURE (% of Fund's net assets)     Options 1.0           Common Stocks 96.7 Domestic Equity Funds 1.9 Options 1.0 Short-Term Investments and Net Other Assets (Liabilities) 0.4 ASSET ALLOCATION (% of Fund's total exposure)     Common Stocks - 96.7                       Domestic Equity Funds - 1.9                Options - 1.0                              Short-Term Investments and Net Other Assets (Liabilities) - 0.4  
Largest Holdings [Text Block] TOP HOLDINGS(% of Fund's net assets)     NVIDIA Corp 7.5   Apple Inc 7.0   Alphabet Inc Class A 5.9   Microsoft Corp 5.6   Amazon.com Inc 4.2   Broadcom Inc 2.9   Meta Platforms Inc Class A 1.9   iShares Core S&P 500 ETF 1.9   Berkshire Hathaway Inc Class B 1.8   JPMorgan Chase & Co 1.8     40.5  
Fidelity Advisor Hedged Equity Fund - Class C  
Shareholder Report [Line Items]  
Fund Name Fidelity® Hedged Equity Fund
Class Name Fidelity Advisor® Hedged Equity Fund Class C
Trading Symbol FEQDX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains information about Fidelity® Hedged Equity Fund for the period February 1, 2026 to July 31, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-877-208-0098 or by sending an e-mail to fidfunddocuments@fidelity.com.
Additional Information Phone Number 1-877-208-0098
Additional Information Email fidfunddocuments@fidelity.com
Additional Information Website fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block] What were your Fund costs for the last six months?
(based on hypothetical $10,000 investment)
 
 
 
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
 
Class C 
$ 79 
1.55%
  
Expenses Paid, Amount $ 79
Expense Ratio, Percent 1.55%
Net Assets $ 768,208,152
Holdings Count | shares 464
Investment Company Portfolio Turnover 98.00%
Additional Fund Statistics [Text Block] Key Fund Statistics
(as of July 31, 2026)
 
KEY FACTS 
  
  
Fund Size
$768,208,152
  
Number of Holdings
464
  
Portfolio Turnover
98%
  
Holdings [Text Block] DERIVATIVE EXPOSURE (% of Fund's net assets)     Options 1.0           Common Stocks 96.7 Domestic Equity Funds 1.9 Options 1.0 Short-Term Investments and Net Other Assets (Liabilities) 0.4 ASSET ALLOCATION (% of Fund's total exposure)     Common Stocks - 96.7                       Domestic Equity Funds - 1.9                Options - 1.0                              Short-Term Investments and Net Other Assets (Liabilities) - 0.4  
Largest Holdings [Text Block] TOP HOLDINGS(% of Fund's net assets)     NVIDIA Corp 7.5   Apple Inc 7.0   Alphabet Inc Class A 5.9   Microsoft Corp 5.6   Amazon.com Inc 4.2   Broadcom Inc 2.9   Meta Platforms Inc Class A 1.9   iShares Core S&P 500 ETF 1.9   Berkshire Hathaway Inc Class B 1.8   JPMorgan Chase & Co 1.8     40.5  
Fidelity Advisor Hedged Equity Fund - Class A  
Shareholder Report [Line Items]  
Fund Name Fidelity® Hedged Equity Fund
Class Name Fidelity Advisor® Hedged Equity Fund Class A
Trading Symbol FEQAX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains information about Fidelity® Hedged Equity Fund for the period February 1, 2026 to July 31, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-877-208-0098 or by sending an e-mail to fidfunddocuments@fidelity.com.
Additional Information Phone Number 1-877-208-0098
Additional Information Email fidfunddocuments@fidelity.com
Additional Information Website fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block] What were your Fund costs for the last six months?
(based on hypothetical $10,000 investment)
 
 
 
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
 
Class A 
$ 41 
0.80%
  
Expenses Paid, Amount $ 41
Expense Ratio, Percent 0.80%
Net Assets $ 768,208,152
Holdings Count | shares 464
Investment Company Portfolio Turnover 98.00%
Additional Fund Statistics [Text Block] Key Fund Statistics
(as of July 31, 2026)
 
KEY FACTS 
  
  
Fund Size
$768,208,152
  
Number of Holdings
464
  
Portfolio Turnover
98%
  
Holdings [Text Block] DERIVATIVE EXPOSURE (% of Fund's net assets)     Options 1.0           Common Stocks 96.7 Domestic Equity Funds 1.9 Options 1.0 Short-Term Investments and Net Other Assets (Liabilities) 0.4 ASSET ALLOCATION (% of Fund's total exposure)     Common Stocks - 96.7                       Domestic Equity Funds - 1.9                Options - 1.0                              Short-Term Investments and Net Other Assets (Liabilities) - 0.4  
Largest Holdings [Text Block] TOP HOLDINGS(% of Fund's net assets)     NVIDIA Corp 7.5   Apple Inc 7.0   Alphabet Inc Class A 5.9   Microsoft Corp 5.6   Amazon.com Inc 4.2   Broadcom Inc 2.9   Meta Platforms Inc Class A 1.9   iShares Core S&P 500 ETF 1.9   Berkshire Hathaway Inc Class B 1.8   JPMorgan Chase & Co 1.8     40.5  
Fidelity Equity Market Neutral Fund  
Shareholder Report [Line Items]  
Fund Name Fidelity® Equity Market Neutral Fund
Class Name Fidelity® Equity Market Neutral Fund
Trading Symbol FEMNX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains information about Fidelity® Equity Market Neutral Fund for the period February 1, 2026 to July 31, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-800-544-8544 or by sending an e-mail to fidfunddocuments@fidelity.com.
Additional Information Phone Number 1-800-544-8544
Additional Information Email fidfunddocuments@fidelity.com
Additional Information Website fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block] What were your Fund costs for the last six months?
(based on hypothetical $10,000 investment)
 
 
 
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
 
Fidelity® Equity Market Neutral Fund 
$ 55 
1.10%
  
Expenses Paid, Amount $ 55
Expense Ratio, Percent 1.10%
Net Assets $ 20,226,263
Holdings Count | shares 167
Investment Company Portfolio Turnover 79.00%
Additional Fund Statistics [Text Block] Key Fund Statistics
(as of July 31, 2026)
 
KEY FACTS 
  
  
Fund Size
$20,226,263
  
Number of Holdings
167
  
Portfolio Turnover
79%
  
Holdings [Text Block] DERIVATIVE EXPOSURE (% of Fund's net assets)     Swaps 126.0   Forward Foreign Currency Contracts 52.6           Swaps 45.2 Common Stocks 34.6 Forward Foreign Currency Contracts 18.9 Short-Term Investments and Net Other Assets (Liabilities) 1.3 ASSET ALLOCATION (% of Fund's total exposure)     Swaps - 45.2                               Common Stocks - 34.6                       Forward Foreign Currency Contracts - 18.9   Short-Term Investments and Net Other Assets (Liabilities) - 1.3  
Largest Holdings [Text Block] TOP HOLDINGS(% of Fund's net assets)     Morgan Stanley Institutional Liquidity Prime Portfolio Institutional Class 5.1   BNP Paribas SA 2.5   Wells Fargo & Co 2.4   Taiwan Semiconductor Manufacturing Co Ltd 2.2   Motorola Solutions Inc 2.2   Microsoft Corp 2.2   Naturgy Energy Group SA 2.1   Bristol-Myers Squibb Co 2.1   Dollar Tree Inc 2.1   Novartis AG 2.1     25.0  
Fidelity Advisor Equity Market Neutral Fund - Class A  
Shareholder Report [Line Items]  
Fund Name Fidelity® Equity Market Neutral Fund
Class Name Fidelity Advisor® Equity Market Neutral Fund Class A
Trading Symbol FEMLX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains information about Fidelity® Equity Market Neutral Fund for the period February 1, 2026 to July 31, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-877-208-0098 or by sending an e-mail to fidfunddocuments@fidelity.com.
Additional Information Phone Number 1-877-208-0098
Additional Information Email fidfunddocuments@fidelity.com
Additional Information Website fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block] What were your Fund costs for the last six months?
(based on hypothetical $10,000 investment)
 
 
 
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
 
Class A 
$ 67 
1.35%
  
Expenses Paid, Amount $ 67
Expense Ratio, Percent 1.35%
Net Assets $ 20,226,263
Holdings Count | shares 167
Investment Company Portfolio Turnover 79.00%
Additional Fund Statistics [Text Block] Key Fund Statistics
(as of July 31, 2026)
 
KEY FACTS 
  
  
Fund Size
$20,226,263
  
Number of Holdings
167
  
Portfolio Turnover
79%
  
Holdings [Text Block] DERIVATIVE EXPOSURE (% of Fund's net assets)     Swaps 126.0   Forward Foreign Currency Contracts 52.6           Swaps 45.2 Common Stocks 34.6 Forward Foreign Currency Contracts 18.9 Short-Term Investments and Net Other Assets (Liabilities) 1.3 ASSET ALLOCATION (% of Fund's total exposure)     Swaps - 45.2                               Common Stocks - 34.6                       Forward Foreign Currency Contracts - 18.9   Short-Term Investments and Net Other Assets (Liabilities) - 1.3  
Largest Holdings [Text Block] TOP HOLDINGS(% of Fund's net assets)     Morgan Stanley Institutional Liquidity Prime Portfolio Institutional Class 5.1   BNP Paribas SA 2.5   Wells Fargo & Co 2.4   Taiwan Semiconductor Manufacturing Co Ltd 2.2   Motorola Solutions Inc 2.2   Microsoft Corp 2.2   Naturgy Energy Group SA 2.1   Bristol-Myers Squibb Co 2.1   Dollar Tree Inc 2.1   Novartis AG 2.1     25.0  
Fidelity Advisor Equity Market Neutral Fund - Class M  
Shareholder Report [Line Items]  
Fund Name Fidelity® Equity Market Neutral Fund
Class Name Fidelity Advisor® Equity Market Neutral Fund Class M
Trading Symbol FEMOX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains information about Fidelity® Equity Market Neutral Fund for the period February 1, 2026 to July 31, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-877-208-0098 or by sending an e-mail to fidfunddocuments@fidelity.com.
Additional Information Phone Number 1-877-208-0098
Additional Information Email fidfunddocuments@fidelity.com
Additional Information Website fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block] What were your Fund costs for the last six months?
(based on hypothetical $10,000 investment)
 
 
 
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
 
Class M 
$ 79 
1.60%
  
Expenses Paid, Amount $ 79
Expense Ratio, Percent 1.60%
Net Assets $ 20,226,263
Holdings Count | shares 167
Investment Company Portfolio Turnover 79.00%
Additional Fund Statistics [Text Block] Key Fund Statistics
(as of July 31, 2026)
 
KEY FACTS 
  
  
Fund Size
$20,226,263
  
Number of Holdings
167
  
Portfolio Turnover
79%
  
Holdings [Text Block] DERIVATIVE EXPOSURE (% of Fund's net assets)     Swaps 126.0   Forward Foreign Currency Contracts 52.6           Swaps 45.2 Common Stocks 34.6 Forward Foreign Currency Contracts 18.9 Short-Term Investments and Net Other Assets (Liabilities) 1.3 ASSET ALLOCATION (% of Fund's total exposure)     Swaps - 45.2                               Common Stocks - 34.6                       Forward Foreign Currency Contracts - 18.9   Short-Term Investments and Net Other Assets (Liabilities) - 1.3  
Largest Holdings [Text Block] TOP HOLDINGS(% of Fund's net assets)     Morgan Stanley Institutional Liquidity Prime Portfolio Institutional Class 5.1   BNP Paribas SA 2.5   Wells Fargo & Co 2.4   Taiwan Semiconductor Manufacturing Co Ltd 2.2   Motorola Solutions Inc 2.2   Microsoft Corp 2.2   Naturgy Energy Group SA 2.1   Bristol-Myers Squibb Co 2.1   Dollar Tree Inc 2.1   Novartis AG 2.1     25.0  
Fidelity Advisor Equity Market Neutral Fund - Class C  
Shareholder Report [Line Items]  
Fund Name Fidelity® Equity Market Neutral Fund
Class Name Fidelity Advisor® Equity Market Neutral Fund Class C
Trading Symbol FEMQX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains information about Fidelity® Equity Market Neutral Fund for the period February 1, 2026 to July 31, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-877-208-0098 or by sending an e-mail to fidfunddocuments@fidelity.com.
Additional Information Phone Number 1-877-208-0098
Additional Information Email fidfunddocuments@fidelity.com
Additional Information Website fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block] What were your Fund costs for the last six months?
(based on hypothetical $10,000 investment)
 
 
 
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
 
Class C 
$ 104 
2.10%
  
Expenses Paid, Amount $ 104
Expense Ratio, Percent 2.10%
Net Assets $ 20,226,263
Holdings Count | shares 167
Investment Company Portfolio Turnover 79.00%
Additional Fund Statistics [Text Block] Key Fund Statistics
(as of July 31, 2026)
 
KEY FACTS 
  
  
Fund Size
$20,226,263
  
Number of Holdings
167
  
Portfolio Turnover
79%
  
Holdings [Text Block] DERIVATIVE EXPOSURE (% of Fund's net assets)     Swaps 126.0   Forward Foreign Currency Contracts 52.6           Swaps 45.2 Common Stocks 34.6 Forward Foreign Currency Contracts 18.9 Short-Term Investments and Net Other Assets (Liabilities) 1.3 ASSET ALLOCATION (% of Fund's total exposure)     Swaps - 45.2                               Common Stocks - 34.6                       Forward Foreign Currency Contracts - 18.9   Short-Term Investments and Net Other Assets (Liabilities) - 1.3  
Largest Holdings [Text Block] TOP HOLDINGS(% of Fund's net assets)     Morgan Stanley Institutional Liquidity Prime Portfolio Institutional Class 5.1   BNP Paribas SA 2.5   Wells Fargo & Co 2.4   Taiwan Semiconductor Manufacturing Co Ltd 2.2   Motorola Solutions Inc 2.2   Microsoft Corp 2.2   Naturgy Energy Group SA 2.1   Bristol-Myers Squibb Co 2.1   Dollar Tree Inc 2.1   Novartis AG 2.1     25.0  
Fidelity Advisor Equity Market Neutral Fund - Class I  
Shareholder Report [Line Items]  
Fund Name Fidelity® Equity Market Neutral Fund
Class Name Fidelity Advisor® Equity Market Neutral Fund Class I
Trading Symbol FEMUX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains information about Fidelity® Equity Market Neutral Fund for the period February 1, 2026 to July 31, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-877-208-0098 or by sending an e-mail to fidfunddocuments@fidelity.com.
Additional Information Phone Number 1-877-208-0098
Additional Information Email fidfunddocuments@fidelity.com
Additional Information Website fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block] What were your Fund costs for the last six months?
(based on hypothetical $10,000 investment)
 
 
 
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
 
Class I 
$ 55 
1.10%
  
Expenses Paid, Amount $ 55
Expense Ratio, Percent 1.10%
Net Assets $ 20,226,263
Holdings Count | shares 167
Investment Company Portfolio Turnover 79.00%
Additional Fund Statistics [Text Block] Key Fund Statistics
(as of July 31, 2026)
 
KEY FACTS 
  
  
Fund Size
$20,226,263
  
Number of Holdings
167
  
Portfolio Turnover
79%
  
Holdings [Text Block] DERIVATIVE EXPOSURE (% of Fund's net assets)     Swaps 126.0   Forward Foreign Currency Contracts 52.6           Swaps 45.2 Common Stocks 34.6 Forward Foreign Currency Contracts 18.9 Short-Term Investments and Net Other Assets (Liabilities) 1.3 ASSET ALLOCATION (% of Fund's total exposure)     Swaps - 45.2                               Common Stocks - 34.6                       Forward Foreign Currency Contracts - 18.9   Short-Term Investments and Net Other Assets (Liabilities) - 1.3  
Largest Holdings [Text Block] TOP HOLDINGS(% of Fund's net assets)     Morgan Stanley Institutional Liquidity Prime Portfolio Institutional Class 5.1   BNP Paribas SA 2.5   Wells Fargo & Co 2.4   Taiwan Semiconductor Manufacturing Co Ltd 2.2   Motorola Solutions Inc 2.2   Microsoft Corp 2.2   Naturgy Energy Group SA 2.1   Bristol-Myers Squibb Co 2.1   Dollar Tree Inc 2.1   Novartis AG 2.1     25.0  
Fidelity Advisor Equity Market Neutral Fund - Class Z  
Shareholder Report [Line Items]  
Fund Name Fidelity® Equity Market Neutral Fund
Class Name Fidelity Advisor® Equity Market Neutral Fund Class Z
Trading Symbol FEMWX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains information about Fidelity® Equity Market Neutral Fund for the period February 1, 2026 to July 31, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-877-208-0098 or by sending an e-mail to fidfunddocuments@fidelity.com.
Additional Information Phone Number 1-877-208-0098
Additional Information Email fidfunddocuments@fidelity.com
Additional Information Website fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block] What were your Fund costs for the last six months?
(based on hypothetical $10,000 investment)
 
 
 
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
 
Class Z 
$ 52 
1.05%
  
Expenses Paid, Amount $ 52
Expense Ratio, Percent 1.05%
Net Assets $ 20,226,263
Holdings Count | shares 167
Investment Company Portfolio Turnover 79.00%
Additional Fund Statistics [Text Block] Key Fund Statistics
(as of July 31, 2026)
 
KEY FACTS 
  
  
Fund Size
$20,226,263
  
Number of Holdings
167
  
Portfolio Turnover
79%
  
Holdings [Text Block] DERIVATIVE EXPOSURE (% of Fund's net assets)     Swaps 126.0   Forward Foreign Currency Contracts 52.6           Swaps 45.2 Common Stocks 34.6 Forward Foreign Currency Contracts 18.9 Short-Term Investments and Net Other Assets (Liabilities) 1.3 ASSET ALLOCATION (% of Fund's total exposure)     Swaps - 45.2                               Common Stocks - 34.6                       Forward Foreign Currency Contracts - 18.9   Short-Term Investments and Net Other Assets (Liabilities) - 1.3  
Largest Holdings [Text Block] TOP HOLDINGS(% of Fund's net assets)     Morgan Stanley Institutional Liquidity Prime Portfolio Institutional Class 5.1   BNP Paribas SA 2.5   Wells Fargo & Co 2.4   Taiwan Semiconductor Manufacturing Co Ltd 2.2   Motorola Solutions Inc 2.2   Microsoft Corp 2.2   Naturgy Energy Group SA 2.1   Bristol-Myers Squibb Co 2.1   Dollar Tree Inc 2.1   Novartis AG 2.1     25.0  
Fidelity Yield Enhanced Equity ETF  
Shareholder Report [Line Items]  
Fund Name Fidelity® Yield Enhanced Equity ETF
Class Name Fidelity® Yield Enhanced Equity ETF
Trading Symbol FYEE
Security Exchange Name CboeBZX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains information about Fidelity® Yield Enhanced Equity ETF for the period February 1, 2026 to July 31, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-800-FIDELITY or by sending an e-mail to fidfunddocuments@fidelity.com.
Additional Information Phone Number 1-800-FIDELITY
Additional Information Email fidfunddocuments@fidelity.com
Additional Information Website fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block] What were your Fund costs for the last six months?
(based on hypothetical $10,000 investment)
 
 
 
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
 
Fidelity® Yield Enhanced Equity ETF 
$ 0 A
0.00%B
  
AAmount represents less than $.50
BAmount represents less than 0.005%
 
Expenses Paid, Amount $ 0
Expense Ratio, Percent 0.00%
Net Assets $ 218,260,352
Holdings Count | shares 185
Investment Company Portfolio Turnover 93.00%
Additional Fund Statistics [Text Block] Key Fund Statistics
(as of July 31, 2026)
 
KEY FACTS 
  
  
Fund Size
$218,260,352
  
Number of Holdings
185
  
Portfolio Turnover
93%
  
Holdings [Text Block] DERIVATIVE EXPOSURE (% of Fund's net assets)     Futures Contracts 2.2   Options (0.4)           Common Stocks 95.6 Futures Contracts 2.1 Short-Term Investments and Net Other Assets (Liabilities) 2.6 ASSET ALLOCATION (% of Fund's total exposure)     Common Stocks - 95.6                       Futures Contracts - 2.1                    Short-Term Investments and Net Other Assets (Liabilities) - 2.6 Options - (0.3)%  
Largest Holdings [Text Block] TOP HOLDINGS(% of Fund's net assets)     NVIDIA Corp 7.8   Apple Inc 7.3   Microsoft Corp 5.1   Amazon.com Inc 4.2   Alphabet Inc Class A 3.7   Broadcom Inc 3.0   Meta Platforms Inc Class A 2.1   Alphabet Inc Class C 2.1   Berkshire Hathaway Inc Class B 2.0   JPMorgan Chase & Co 1.9     39.2  
Fidelity Dynamic Buffered Equity ETF  
Shareholder Report [Line Items]  
Fund Name Fidelity® Dynamic Buffered Equity ETF
Class Name Fidelity® Dynamic Buffered Equity ETF
Trading Symbol FBUF
Security Exchange Name CboeBZX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains information about Fidelity® Dynamic Buffered Equity ETF for the period February 1, 2026 to July 31, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-800-FIDELITY or by sending an e-mail to fidfunddocuments@fidelity.com.
Additional Information Phone Number 1-800-FIDELITY
Additional Information Email fidfunddocuments@fidelity.com
Additional Information Website fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block] What were your Fund costs for the last six months?
(based on hypothetical $10,000 investment)
 
 
 
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
 
Fidelity® Dynamic Buffered Equity ETF 
$ 25 
0.48%
  
Expenses Paid, Amount $ 25
Expense Ratio, Percent 0.48%
Net Assets $ 23,897,902
Holdings Count | shares 181
Investment Company Portfolio Turnover 89.00%
Additional Fund Statistics [Text Block] Key Fund Statistics
(as of July 31, 2026)
 
KEY FACTS 
  
  
Fund Size
$23,897,902
  
Number of Holdings
181
  
Portfolio Turnover
89%
  
Holdings [Text Block] DERIVATIVE EXPOSURE (% of Fund's net assets)     Futures Contracts 1.3   Options 0.0           Common Stocks 97.0 Futures Contracts 1.2 Options 0.1 Short-Term Investments and Net Other Assets (Liabilities) 1.7 ASSET ALLOCATION (% of Fund's total exposure)     Common Stocks - 97.0                       Futures Contracts - 1.2                    Options - 0.1                              Short-Term Investments and Net Other Assets (Liabilities) - 1.7  
Largest Holdings [Text Block] TOP HOLDINGS(% of Fund's net assets)     NVIDIA Corp 7.8   Apple Inc 7.3   Microsoft Corp 4.9   Amazon.com Inc 4.3   Alphabet Inc Class A 3.6   Broadcom Inc 3.0   Alphabet Inc Class C 2.4   Meta Platforms Inc Class A 2.0   Berkshire Hathaway Inc Class B 2.0   JPMorgan Chase & Co 1.9     39.2  
Fidelity Hedged Equity ETF  
Shareholder Report [Line Items]  
Fund Name Fidelity® Hedged Equity ETF
Class Name Fidelity® Hedged Equity ETF
Trading Symbol FHEQ
Security Exchange Name CboeBZX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains information about Fidelity® Hedged Equity ETF for the period February 1, 2026 to July 31, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-800-FIDELITY or by sending an e-mail to fidfunddocuments@fidelity.com.
Additional Information Phone Number 1-800-FIDELITY
Additional Information Email fidfunddocuments@fidelity.com
Additional Information Website fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block] What were your Fund costs for the last six months?
(based on hypothetical $10,000 investment)
 
 
 
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
 
Fidelity® Hedged Equity ETF 
$ 25 
0.48%
  
Expenses Paid, Amount $ 25
Expense Ratio, Percent 0.48%
Net Assets $ 928,895,897
Holdings Count | shares 193
Investment Company Portfolio Turnover 89.00%
Additional Fund Statistics [Text Block] Key Fund Statistics
(as of July 31, 2026)
 
KEY FACTS 
  
  
Fund Size
$928,895,897
  
Number of Holdings
193
  
Portfolio Turnover
89%
  
Holdings [Text Block] DERIVATIVE EXPOSURE (% of Fund's net assets)     Futures Contracts 0.6   Options 1.0           Common Stocks 97.0 Options 1.0 Futures Contracts 0.6 Short-Term Investments and Net Other Assets (Liabilities) 1.4 ASSET ALLOCATION (% of Fund's total exposure)     Common Stocks - 97.0                       Options - 1.0                              Futures Contracts - 0.6                    Short-Term Investments and Net Other Assets (Liabilities) - 1.4  
Largest Holdings [Text Block] TOP HOLDINGS(% of Fund's net assets)     NVIDIA Corp 7.8   Apple Inc 7.3   Microsoft Corp 5.2   Amazon.com Inc 4.2   Alphabet Inc Class A 3.4   Broadcom Inc 2.9   Alphabet Inc Class C 2.5   Meta Platforms Inc Class A 2.0   Berkshire Hathaway Inc Class B 2.0   JPMorgan Chase & Co 1.9     39.2  
Fidelity Managed Futures ETF  
Shareholder Report [Line Items]  
Fund Name Fidelity® Managed Futures ETF
Class Name Fidelity® Managed Futures ETF
Trading Symbol FFUT
Security Exchange Name NASDAQ
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains information about Fidelity® Managed Futures ETF for the period February 1, 2026 to July 31, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-800-FIDELITY or by sending an e-mail to fidfunddocuments@fidelity.com.
Additional Information Phone Number 1-800-FIDELITY
Additional Information Email fidfunddocuments@fidelity.com
Additional Information Website fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block] What were your Fund costs for the last six months?
(based on hypothetical $10,000 investment)
 
 
 
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
 
Fidelity® Managed Futures ETF 
$ 42 
0.80%
  
Expenses Paid, Amount $ 42
Expense Ratio, Percent 0.80%
Net Assets $ 331,106,086
Holdings Count | shares 423
Investment Company Portfolio Turnover 19.00%
Additional Fund Statistics [Text Block] Key Fund Statistics
(as of July 31, 2026)
 
KEY FACTS 
  
  
Fund Size
$331,106,086
  
Number of Holdings
423
  
Portfolio Turnover
19%
  
Holdings [Text Block] DERIVATIVE EXPOSURE (% of Fund's net assets)     Futures Contracts 850.9   Swaps 199.4   Forward Foreign Currency Contracts 351.7           Futures Contracts 56.7 Forward Foreign Currency Contracts 23.4 Swaps 13.2 Domestic Equity Funds 0.3 Common Stocks 0.2 Short-Term Investments and Net Other Assets (Liabilities) 6.2 ASSET ALLOCATION (% of Fund's total exposure)     Futures Contracts - 56.7                   Forward Foreign Currency Contracts - 23.4   Swaps - 13.2                               Domestic Equity Funds - 0.3                Common Stocks - 0.2                        Short-Term Investments and Net Other Assets (Liabilities) - 6.2  
Largest Holdings [Text Block] TOP HOLDINGS(% of Fund's net assets)     US Treasury Bill 49.6   iShares Core S&P 500 ETF 3.8   NVIDIA Corp 2.1   Microsoft Corp 0.8     56.3  
Fidelity SAI Merger Arbitrage Fund  
Shareholder Report [Line Items]  
Fund Name Fidelity® SAI Merger Arbitrage Fund
Class Name Fidelity® SAI Merger Arbitrage Fund
Trading Symbol FMADX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains information about Fidelity® SAI Merger Arbitrage Fund for the period February 1, 2026 to July 31, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-800-544-3455 or by sending an e-mail to fidfunddocuments@fidelity.com.
Additional Information Phone Number 1-800-544-3455
Additional Information Email fidfunddocuments@fidelity.com
Additional Information Website fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block] What were your Fund costs for the last six months?
(based on hypothetical $10,000 investment)
 
 
 
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
 
Fidelity® SAI Merger Arbitrage Fund 
$ 56 
1.10%
  
Expenses Paid, Amount $ 56
Expense Ratio, Percent 1.10%
Net Assets $ 637,050,306
Holdings Count | shares 36
Investment Company Portfolio Turnover 113.00%
Additional Fund Statistics [Text Block] Key Fund Statistics
(as of July 31, 2026)
 
KEY FACTS 
  
  
Fund Size
$637,050,306
  
Number of Holdings
36
  
Portfolio Turnover
113%
  
Holdings [Text Block] DERIVATIVE EXPOSURE (% of Fund's net assets)     Swaps 60.3   Options 0.2           Common Stocks 54.7 Swaps 37.6 Options 0.0 Short-Term Investments and Net Other Assets (Liabilities) 7.7 ASSET ALLOCATION (% of Fund's total exposure)     Common Stocks - 54.7                       Swaps - 37.6                               Options - 0.0                              Short-Term Investments and Net Other Assets (Liabilities) - 7.7  
Largest Holdings [Text Block] TOP HOLDINGS(% of Fund's net assets)     Mastercard Inc Class A 15.1   US Treasury Bill 12.3   Warner Bros Discovery Inc 9.8   Kenvue Inc 9.0   Electronic Arts Inc 8.2   NVIDIA Corp 7.9   DigitalBridge Group Inc Class A 5.0   Apogee Therapeutics Inc 5.0   Crinetics Pharmaceuticals Inc 4.3   Bio-Techne Corp 4.2     80.8  
Fidelity SAI Managed Futures Fund  
Shareholder Report [Line Items]  
Fund Name Fidelity® SAI Managed Futures Fund
Class Name Fidelity® SAI Managed Futures Fund
Trading Symbol FMFLX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains information about Fidelity® SAI Managed Futures Fund for the period February 1, 2026 to July 31, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-800-544-3455 or by sending an e-mail to fidfunddocuments@fidelity.com.
Additional Information Phone Number 1-800-544-3455
Additional Information Email fidfunddocuments@fidelity.com
Additional Information Website fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block] What were your Fund costs for the last six months?
(based on hypothetical $10,000 investment)
 
 
 
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
 
Fidelity® SAI Managed Futures Fund 
$ 55 
1.05%
  
Expenses Paid, Amount $ 55
Expense Ratio, Percent 1.05%
Net Assets $ 269,292,119
Holdings Count | shares 361
Investment Company Portfolio Turnover 27.00%
Additional Fund Statistics [Text Block] Key Fund Statistics
(as of July 31, 2026)
 
KEY FACTS 
  
  
Fund Size
$269,292,119
  
Number of Holdings
361
  
Portfolio Turnover
27%
  
Holdings [Text Block] DERIVATIVE EXPOSURE (% of Fund's net assets)     Futures Contracts 841.6   Swaps 152.6   Forward Foreign Currency Contracts 300.4           Futures Contracts 60.4 Forward Foreign Currency Contracts 21.6 Swaps 10.9 Domestic Equity Funds 0.4 Common Stocks 0.1 Short-Term Investments and Net Other Assets (Liabilities) 6.6 ASSET ALLOCATION (% of Fund's total exposure)     Futures Contracts - 60.4                   Forward Foreign Currency Contracts - 21.6   Swaps - 10.9                               Domestic Equity Funds - 0.4                Common Stocks - 0.1                        Short-Term Investments and Net Other Assets (Liabilities) - 6.6  
Largest Holdings [Text Block] TOP HOLDINGS(% of Fund's net assets)     US Treasury Bill 50.5   iShares Core S&P 500 ETF 4.4   Vanguard S&P 500 ETF 1.4   Microsoft Corp 1.1   NVIDIA Corp 0.9     58.3