v3.26.3
Shareholder Report, Line Graph (Details) - USD ($)
12 Months Ended 120 Months Ended 132 Months Ended
Jul. 31, 2026
Jul. 31, 2026
Jul. 31, 2026
C000161034_0_LG_BBIndexMember_11YRMember      
Account Value [Line Items]      
Line Graph and Table Measure Name     <span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">S&P 500® Index</span>
C000161034_0_BBIndexMember_AsOf_2016Member      
Account Value [Line Items]      
Accumulated Value $ 10,000    
C000161034_0_BBIndexMember_AsOf_2017Member      
Account Value [Line Items]      
Accumulated Value 11,604    
C000161034_0_BBIndexMember_AsOf_2018Member      
Account Value [Line Items]      
Accumulated Value 13,489    
C000161034_0_BBIndexMember_AsOf_2019Member      
Account Value [Line Items]      
Accumulated Value 14,566    
C000161034_0_BBIndexMember_AsOf_2020Member      
Account Value [Line Items]      
Accumulated Value 16,308    
C000161034_0_BBIndexMember_AsOf_2021Member      
Account Value [Line Items]      
Accumulated Value 22,251    
C000161034_0_BBIndexMember_AsOf_2022Member      
Account Value [Line Items]      
Accumulated Value 21,219    
C000161034_0_BBIndexMember_AsOf_2023Member      
Account Value [Line Items]      
Accumulated Value 23,980    
C000161034_0_BBIndexMember_AsOf_2024Member      
Account Value [Line Items]      
Accumulated Value 29,292    
C000161034_0_BBIndexMember_AsOf_2025Member      
Account Value [Line Items]      
Accumulated Value 34,076    
C000161034_0_BBIndexMember_AsOf_2026Member      
Account Value [Line Items]      
Accumulated Value 40,742    
C000177148_0_LG_BBIndexMember_10YRMember      
Account Value [Line Items]      
Line Graph and Table Measure Name   <span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">MSCI USA Custom Momentum Composite Index</span>  
C000177148_0_BBIndexMember_AsOf_2017Member      
Account Value [Line Items]      
Accumulated Value 10,000    
C000177148_0_BBIndexMember_AsOf_2018Member      
Account Value [Line Items]      
Accumulated Value 10,980    
C000177148_0_BBIndexMember_AsOf_2019Member      
Account Value [Line Items]      
Accumulated Value 13,432    
C000177148_0_BBIndexMember_AsOf_2020Member      
Account Value [Line Items]      
Accumulated Value 14,363    
C000177148_0_BBIndexMember_AsOf_2021Member      
Account Value [Line Items]      
Accumulated Value 16,770    
C000177148_0_BBIndexMember_AsOf_2022Member      
Account Value [Line Items]      
Accumulated Value 22,301    
C000177148_0_BBIndexMember_AsOf_2023Member      
Account Value [Line Items]      
Accumulated Value 19,835    
C000177148_0_BBIndexMember_AsOf_2024Member      
Account Value [Line Items]      
Accumulated Value 21,024    
C000177148_0_BBIndexMember_AsOf_2025Member      
Account Value [Line Items]      
Accumulated Value 28,399    
C000177148_0_BBIndexMember_AsOf_2026Member      
Account Value [Line Items]      
Accumulated Value 34,738    
C000177148_4_LG_BBIndexMember_10YRMember      
Account Value [Line Items]      
Line Graph and Table Measure Name   <span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">MSCI USA Index</span>  
C000177148_4_BBIndexMember_AsOf_2017Member      
Account Value [Line Items]      
Accumulated Value 10,000    
C000177148_4_BBIndexMember_AsOf_2018Member      
Account Value [Line Items]      
Accumulated Value 10,768    
C000177148_4_BBIndexMember_AsOf_2019Member      
Account Value [Line Items]      
Accumulated Value 12,450    
C000177148_4_BBIndexMember_AsOf_2020Member      
Account Value [Line Items]      
Accumulated Value 13,375    
C000177148_4_BBIndexMember_AsOf_2021Member      
Account Value [Line Items]      
Accumulated Value 15,041    
C000177148_4_BBIndexMember_AsOf_2022Member      
Account Value [Line Items]      
Accumulated Value 20,620    
C000177148_4_BBIndexMember_AsOf_2023Member      
Account Value [Line Items]      
Accumulated Value 19,123    
C000177148_4_BBIndexMember_AsOf_2024Member      
Account Value [Line Items]      
Accumulated Value 21,529    
C000177148_4_BBIndexMember_AsOf_2025Member      
Account Value [Line Items]      
Accumulated Value 26,154    
C000177148_4_BBIndexMember_AsOf_2026Member      
Account Value [Line Items]      
Accumulated Value 30,471    
C000158877_0_LG_BBIndexMember_11YRMember      
Account Value [Line Items]      
Line Graph and Table Measure Name     <span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Russell SMID 500™ Index</span>
C000158877_0_BBIndexMember_AsOf_2016Member      
Account Value [Line Items]      
Accumulated Value 10,000    
C000158877_0_BBIndexMember_AsOf_2017Member      
Account Value [Line Items]      
Accumulated Value 11,241    
C000158877_0_BBIndexMember_AsOf_2018Member      
Account Value [Line Items]      
Accumulated Value 13,029    
C000158877_0_BBIndexMember_AsOf_2019Member      
Account Value [Line Items]      
Accumulated Value 13,715    
C000158877_0_BBIndexMember_AsOf_2020Member      
Account Value [Line Items]      
Accumulated Value 13,711    
C000158877_0_BBIndexMember_AsOf_2021Member      
Account Value [Line Items]      
Accumulated Value 20,154    
C000158877_0_BBIndexMember_AsOf_2022Member      
Account Value [Line Items]      
Accumulated Value 18,353    
C000158877_0_BBIndexMember_AsOf_2023Member      
Account Value [Line Items]      
Accumulated Value 19,880    
C000158877_0_BBIndexMember_AsOf_2024Member      
Account Value [Line Items]      
Accumulated Value 22,301    
C000158877_0_BBIndexMember_AsOf_2025Member      
Account Value [Line Items]      
Accumulated Value 24,064    
C000158877_0_BBIndexMember_AsOf_2026Member      
Account Value [Line Items]      
Accumulated Value 30,936    
C000158877_4_LG_BBIndexMember_11YRMember      
Account Value [Line Items]      
Line Graph and Table Measure Name     <span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Russell 3000® Index</span>
C000158877_4_BBIndexMember_AsOf_2016Member      
Account Value [Line Items]      
Accumulated Value 10,000    
C000158877_4_BBIndexMember_AsOf_2017Member      
Account Value [Line Items]      
Accumulated Value 11,614    
C000158877_4_BBIndexMember_AsOf_2018Member      
Account Value [Line Items]      
Accumulated Value 13,517    
C000158877_4_BBIndexMember_AsOf_2019Member      
Account Value [Line Items]      
Accumulated Value 14,470    
C000158877_4_BBIndexMember_AsOf_2020Member      
Account Value [Line Items]      
Accumulated Value 16,052    
C000158877_4_BBIndexMember_AsOf_2021Member      
Account Value [Line Items]      
Accumulated Value 22,268    
C000158877_4_BBIndexMember_AsOf_2022Member      
Account Value [Line Items]      
Accumulated Value 20,631    
C000158877_4_BBIndexMember_AsOf_2023Member      
Account Value [Line Items]      
Accumulated Value 23,240    
C000158877_4_BBIndexMember_AsOf_2024Member      
Account Value [Line Items]      
Accumulated Value 28,138    
C000158877_4_BBIndexMember_AsOf_2025Member      
Account Value [Line Items]      
Accumulated Value 32,551    
C000158877_4_BBIndexMember_AsOf_2026Member      
Account Value [Line Items]      
Accumulated Value 38,932    
C000163539_0_LG_BBIndexMember_11YRMember      
Account Value [Line Items]      
Line Graph and Table Measure Name     <span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">S&P 500® Index</span>
C000163539_0_BBIndexMember_AsOf_2016Member      
Account Value [Line Items]      
Accumulated Value 10,000    
C000163539_0_BBIndexMember_AsOf_2017Member      
Account Value [Line Items]      
Accumulated Value 11,604    
C000163539_0_BBIndexMember_AsOf_2018Member      
Account Value [Line Items]      
Accumulated Value 13,489    
C000163539_0_BBIndexMember_AsOf_2019Member      
Account Value [Line Items]      
Accumulated Value 14,566    
C000163539_0_BBIndexMember_AsOf_2020Member      
Account Value [Line Items]      
Accumulated Value 16,308    
C000163539_0_BBIndexMember_AsOf_2021Member      
Account Value [Line Items]      
Accumulated Value 22,251    
C000163539_0_BBIndexMember_AsOf_2022Member      
Account Value [Line Items]      
Accumulated Value 21,219    
C000163539_0_BBIndexMember_AsOf_2023Member      
Account Value [Line Items]      
Accumulated Value 23,980    
C000163539_0_BBIndexMember_AsOf_2024Member      
Account Value [Line Items]      
Accumulated Value 29,292    
C000163539_0_BBIndexMember_AsOf_2025Member      
Account Value [Line Items]      
Accumulated Value 34,076    
C000163539_0_BBIndexMember_AsOf_2026Member      
Account Value [Line Items]      
Accumulated Value 40,742    
C000103377_0_LG_BBIndexMember_11YRMember      
Account Value [Line Items]      
Line Graph and Table Measure Name     <span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">S&P 500® Index</span>
C000103377_0_BBIndexMember_AsOf_2016Member      
Account Value [Line Items]      
Accumulated Value 10,000    
C000103377_0_BBIndexMember_AsOf_2017Member      
Account Value [Line Items]      
Accumulated Value 11,604    
C000103377_0_BBIndexMember_AsOf_2018Member      
Account Value [Line Items]      
Accumulated Value 13,489    
C000103377_0_BBIndexMember_AsOf_2019Member      
Account Value [Line Items]      
Accumulated Value 14,566    
C000103377_0_BBIndexMember_AsOf_2020Member      
Account Value [Line Items]      
Accumulated Value 16,308    
C000103377_0_BBIndexMember_AsOf_2021Member      
Account Value [Line Items]      
Accumulated Value 22,251    
C000103377_0_BBIndexMember_AsOf_2022Member      
Account Value [Line Items]      
Accumulated Value 21,219    
C000103377_0_BBIndexMember_AsOf_2023Member      
Account Value [Line Items]      
Accumulated Value 23,980    
C000103377_0_BBIndexMember_AsOf_2024Member      
Account Value [Line Items]      
Accumulated Value 29,292    
C000103377_0_BBIndexMember_AsOf_2025Member      
Account Value [Line Items]      
Accumulated Value 34,076    
C000103377_0_BBIndexMember_AsOf_2026Member      
Account Value [Line Items]      
Accumulated Value 40,742    
C000195574_LG_ClassMember_10YRMember      
Account Value [Line Items]      
Line Graph and Table Measure Name   <span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Fidelity® SAI U.S. Value Index Fund</span>  
C000195574_ClassMember_AsOf_2017Member      
Account Value [Line Items]      
Accumulated Value 10,000    
C000195574_ClassMember_AsOf_2018Member      
Account Value [Line Items]      
Accumulated Value 10,367    
C000195574_ClassMember_AsOf_2019Member      
Account Value [Line Items]      
Accumulated Value 10,431    
C000195574_ClassMember_AsOf_2020Member      
Account Value [Line Items]      
Accumulated Value 9,375    
C000195574_ClassMember_AsOf_2021Member      
Account Value [Line Items]      
Accumulated Value 13,348    
C000195574_ClassMember_AsOf_2022Member      
Account Value [Line Items]      
Accumulated Value 14,044    
C000195574_ClassMember_AsOf_2023Member      
Account Value [Line Items]      
Accumulated Value 14,991    
C000195574_ClassMember_AsOf_2024Member      
Account Value [Line Items]      
Accumulated Value 17,716    
C000195574_ClassMember_AsOf_2025Member      
Account Value [Line Items]      
Accumulated Value 19,237    
C000195574_ClassMember_AsOf_2026Member      
Account Value [Line Items]      
Accumulated Value 26,182    
C000195574_LG_1_AdditionalIndexMember_10YRMember      
Account Value [Line Items]      
Line Graph and Table Measure Name   <span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Fidelity U.S. Value Focus Index℠</span>  
C000195574_1_AdditionalIndexMember_AsOf_2017Member      
Account Value [Line Items]      
Accumulated Value 10,000    
C000195574_1_AdditionalIndexMember_AsOf_2018Member      
Account Value [Line Items]      
Accumulated Value 10,382    
C000195574_1_AdditionalIndexMember_AsOf_2019Member      
Account Value [Line Items]      
Accumulated Value 10,441    
C000195574_1_AdditionalIndexMember_AsOf_2020Member      
Account Value [Line Items]      
Accumulated Value 9,377    
C000195574_1_AdditionalIndexMember_AsOf_2021Member      
Account Value [Line Items]      
Accumulated Value 13,369    
C000195574_1_AdditionalIndexMember_AsOf_2022Member      
Account Value [Line Items]      
Accumulated Value 14,083    
C000195574_1_AdditionalIndexMember_AsOf_2023Member      
Account Value [Line Items]      
Accumulated Value 15,064    
C000195574_1_AdditionalIndexMember_AsOf_2024Member      
Account Value [Line Items]      
Accumulated Value 17,800    
C000195574_1_AdditionalIndexMember_AsOf_2025Member      
Account Value [Line Items]      
Accumulated Value 19,341    
C000195574_1_AdditionalIndexMember_AsOf_2026Member      
Account Value [Line Items]      
Accumulated Value 26,358    
C000195574_LG_2_AdditionalIndexMember_10YRMember      
Account Value [Line Items]      
Line Graph and Table Measure Name   <span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">S&P 500® Index</span>  
C000195574_2_AdditionalIndexMember_AsOf_2017Member      
Account Value [Line Items]      
Accumulated Value 10,000    
C000195574_2_AdditionalIndexMember_AsOf_2018Member      
Account Value [Line Items]      
Accumulated Value 10,621    
C000195574_2_AdditionalIndexMember_AsOf_2019Member      
Account Value [Line Items]      
Accumulated Value 11,469    
C000195574_2_AdditionalIndexMember_AsOf_2020Member      
Account Value [Line Items]      
Accumulated Value 12,841    
C000195574_2_AdditionalIndexMember_AsOf_2021Member      
Account Value [Line Items]      
Accumulated Value 17,520    
C000195574_2_AdditionalIndexMember_AsOf_2022Member      
Account Value [Line Items]      
Accumulated Value 16,708    
C000195574_2_AdditionalIndexMember_AsOf_2023Member      
Account Value [Line Items]      
Accumulated Value 18,882    
C000195574_2_AdditionalIndexMember_AsOf_2024Member      
Account Value [Line Items]      
Accumulated Value 23,064    
C000195574_2_AdditionalIndexMember_AsOf_2025Member      
Account Value [Line Items]      
Accumulated Value 26,831    
C000195574_2_AdditionalIndexMember_AsOf_2026Member      
Account Value [Line Items]      
Accumulated Value 32,080    
C000161034_LG_ClassMember_11YRMember      
Account Value [Line Items]      
Line Graph and Table Measure Name     <span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Fidelity® SAI U.S. Quality Index Fund</span>
C000161034_ClassMember_AsOf_2016Member      
Account Value [Line Items]      
Accumulated Value 10,000    
C000161034_ClassMember_AsOf_2017Member      
Account Value [Line Items]      
Accumulated Value 11,470    
C000161034_ClassMember_AsOf_2018Member      
Account Value [Line Items]      
Accumulated Value 13,845    
C000161034_ClassMember_AsOf_2019Member      
Account Value [Line Items]      
Accumulated Value 15,188    
C000161034_ClassMember_AsOf_2020Member      
Account Value [Line Items]      
Accumulated Value 18,246    
C000161034_ClassMember_AsOf_2021Member      
Account Value [Line Items]      
Accumulated Value 24,203    
C000161034_ClassMember_AsOf_2022Member      
Account Value [Line Items]      
Accumulated Value 22,617    
C000161034_ClassMember_AsOf_2023Member      
Account Value [Line Items]      
Accumulated Value 26,002    
C000161034_ClassMember_AsOf_2024Member      
Account Value [Line Items]      
Accumulated Value 32,725    
C000161034_ClassMember_AsOf_2025Member      
Account Value [Line Items]      
Accumulated Value 37,363    
C000161034_ClassMember_AsOf_2026Member      
Account Value [Line Items]      
Accumulated Value 43,741    
C000161034_LG_1_AdditionalIndexMember_11YRMember      
Account Value [Line Items]      
Line Graph and Table Measure Name     <span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Fidelity SAI U.S. Quality Index Fund Linked Index℠</span>
C000161034_1_AdditionalIndexMember_AsOf_2016Member      
Account Value [Line Items]      
Accumulated Value 10,000    
C000161034_1_AdditionalIndexMember_AsOf_2017Member      
Account Value [Line Items]      
Accumulated Value 11,496    
C000161034_1_AdditionalIndexMember_AsOf_2018Member      
Account Value [Line Items]      
Accumulated Value 13,893    
C000161034_1_AdditionalIndexMember_AsOf_2019Member      
Account Value [Line Items]      
Accumulated Value 15,251    
C000161034_1_AdditionalIndexMember_AsOf_2020Member      
Account Value [Line Items]      
Accumulated Value 18,325    
C000161034_1_AdditionalIndexMember_AsOf_2021Member      
Account Value [Line Items]      
Accumulated Value 24,321    
C000161034_1_AdditionalIndexMember_AsOf_2022Member      
Account Value [Line Items]      
Accumulated Value 22,722    
C000161034_1_AdditionalIndexMember_AsOf_2023Member      
Account Value [Line Items]      
Accumulated Value 26,170    
C000161034_1_AdditionalIndexMember_AsOf_2024Member      
Account Value [Line Items]      
Accumulated Value 32,910    
C000161034_1_AdditionalIndexMember_AsOf_2025Member      
Account Value [Line Items]      
Accumulated Value 37,680    
C000161034_1_AdditionalIndexMember_AsOf_2026Member      
Account Value [Line Items]      
Accumulated Value 44,334    
C000161034_LG_2_AdditionalIndexMember_11YRMember      
Account Value [Line Items]      
Line Graph and Table Measure Name     <span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Fidelity U.S. Quality Focus Index℠</span>
C000161034_2_AdditionalIndexMember_AsOf_2016Member      
Account Value [Line Items]      
Accumulated Value 10,000    
C000161034_2_AdditionalIndexMember_AsOf_2017Member      
Account Value [Line Items]      
Accumulated Value 11,470    
C000161034_2_AdditionalIndexMember_AsOf_2018Member      
Account Value [Line Items]      
Accumulated Value 13,845    
C000161034_2_AdditionalIndexMember_AsOf_2019Member      
Account Value [Line Items]      
Accumulated Value 15,204    
C000161034_2_AdditionalIndexMember_AsOf_2020Member      
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Accumulated Value 18,268    
C000161034_2_AdditionalIndexMember_AsOf_2021Member      
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Accumulated Value 24,246    
C000161034_2_AdditionalIndexMember_AsOf_2022Member      
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Accumulated Value 22,651    
C000161034_2_AdditionalIndexMember_AsOf_2023Member      
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Accumulated Value 26,088    
C000161034_2_AdditionalIndexMember_AsOf_2024Member      
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Accumulated Value 32,808    
C000161034_2_AdditionalIndexMember_AsOf_2025Member      
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Accumulated Value 37,563    
C000161034_2_AdditionalIndexMember_AsOf_2026Member      
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Accumulated Value 44,196    
C000177148_LG_ClassMember_10YRMember      
Account Value [Line Items]      
Line Graph and Table Measure Name   <span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Fidelity® SAI U.S. Momentum Index Fund</span>  
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Account Value [Line Items]      
Accumulated Value 10,000    
C000177148_ClassMember_AsOf_2018Member      
Account Value [Line Items]      
Accumulated Value 10,980    
C000177148_ClassMember_AsOf_2019Member      
Account Value [Line Items]      
Accumulated Value 13,432    
C000177148_ClassMember_AsOf_2020Member      
Account Value [Line Items]      
Accumulated Value 14,363    
C000177148_ClassMember_AsOf_2021Member      
Account Value [Line Items]      
Accumulated Value 16,770    
C000177148_ClassMember_AsOf_2022Member      
Account Value [Line Items]      
Accumulated Value 22,301    
C000177148_ClassMember_AsOf_2023Member      
Account Value [Line Items]      
Accumulated Value 19,835    
C000177148_ClassMember_AsOf_2024Member      
Account Value [Line Items]      
Accumulated Value 21,024    
C000177148_ClassMember_AsOf_2025Member      
Account Value [Line Items]      
Accumulated Value 28,399    
C000177148_ClassMember_AsOf_2026Member      
Account Value [Line Items]      
Accumulated Value 34,738    
C000177148_LG_1_AdditionalIndexMember_10YRMember      
Account Value [Line Items]      
Line Graph and Table Measure Name   <span style="font-family:'Fidelity Sans';font-size:9px;color:#000000;font-style:normal;font-weight:normal;">Fidelity U.S. Momentum Linked Index</span>  
C000177148_1_AdditionalIndexMember_AsOf_2017Member      
Account Value [Line Items]      
Accumulated Value 10,000    
C000177148_1_AdditionalIndexMember_AsOf_2018Member      
Account Value [Line Items]      
Accumulated Value 11,002    
C000177148_1_AdditionalIndexMember_AsOf_2019Member      
Account Value [Line Items]      
Accumulated Value 13,464    
C000177148_1_AdditionalIndexMember_AsOf_2020Member      
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Accumulated Value 14,416    
C000177148_1_AdditionalIndexMember_AsOf_2021Member      
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Accumulated Value 16,851    
C000177148_1_AdditionalIndexMember_AsOf_2022Member      
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Accumulated Value 22,435    
C000177148_1_AdditionalIndexMember_AsOf_2023Member      
Account Value [Line Items]      
Accumulated Value 19,974    
C000177148_1_AdditionalIndexMember_AsOf_2024Member      
Account Value [Line Items]      
Accumulated Value 21,212    
C000177148_1_AdditionalIndexMember_AsOf_2025Member      
Account Value [Line Items]      
Accumulated Value 28,645    
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