v3.26.3
Shareholder Report, Line Graph (Details) - USD ($)
12 Months Ended 132 Months Ended
Jul. 31, 2026
Jul. 31, 2026
C000133805_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;">Bloomberg Commodity Total Return Index</span>
C000133805_0_BBIndexMember_AsOf_2016Member    
Account Value [Line Items]    
Accumulated Value $ 10,000  
C000133805_0_BBIndexMember_AsOf_2017Member    
Account Value [Line Items]    
Accumulated Value 9,273  
C000133805_0_BBIndexMember_AsOf_2018Member    
Account Value [Line Items]    
Accumulated Value 9,526  
C000133805_0_BBIndexMember_AsOf_2019Member    
Account Value [Line Items]    
Accumulated Value 9,015  
C000133805_0_BBIndexMember_AsOf_2020Member    
Account Value [Line Items]    
Accumulated Value 7,927  
C000133805_0_BBIndexMember_AsOf_2021Member    
Account Value [Line Items]    
Accumulated Value 11,120  
C000133805_0_BBIndexMember_AsOf_2022Member    
Account Value [Line Items]    
Accumulated Value 14,147  
C000133805_0_BBIndexMember_AsOf_2023Member    
Account Value [Line Items]    
Accumulated Value 13,032  
C000133805_0_BBIndexMember_AsOf_2024Member    
Account Value [Line Items]    
Accumulated Value 12,358  
C000133805_0_BBIndexMember_AsOf_2025Member    
Account Value [Line Items]    
Accumulated Value 13,558  
C000133805_0_BBIndexMember_AsOf_2026Member    
Account Value [Line Items]    
Accumulated Value 19,969  
C000133805_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;">MSCI ACWI (All Country World Index) Index</span>
C000133805_4_BBIndexMember_AsOf_2016Member    
Account Value [Line Items]    
Accumulated Value 10,000  
C000133805_4_BBIndexMember_AsOf_2017Member    
Account Value [Line Items]    
Accumulated Value 11,753  
C000133805_4_BBIndexMember_AsOf_2018Member    
Account Value [Line Items]    
Accumulated Value 13,092  
C000133805_4_BBIndexMember_AsOf_2019Member    
Account Value [Line Items]    
Accumulated Value 13,532  
C000133805_4_BBIndexMember_AsOf_2020Member    
Account Value [Line Items]    
Accumulated Value 14,564  
C000133805_4_BBIndexMember_AsOf_2021Member    
Account Value [Line Items]    
Accumulated Value 19,458  
C000133805_4_BBIndexMember_AsOf_2022Member    
Account Value [Line Items]    
Accumulated Value 17,474  
C000133805_4_BBIndexMember_AsOf_2023Member    
Account Value [Line Items]    
Accumulated Value 19,804  
C000133805_4_BBIndexMember_AsOf_2024Member    
Account Value [Line Items]    
Accumulated Value 23,253  
C000133805_4_BBIndexMember_AsOf_2025Member    
Account Value [Line Items]    
Accumulated Value 27,031  
C000133805_4_BBIndexMember_AsOf_2026Member    
Account Value [Line Items]    
Accumulated Value 33,101  
C000133805_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® Commodity Strategy Central Fund</span>
C000133805_ClassMember_AsOf_2016Member    
Account Value [Line Items]    
Accumulated Value 10,000  
C000133805_ClassMember_AsOf_2017Member    
Account Value [Line Items]    
Accumulated Value 10,177  
C000133805_ClassMember_AsOf_2018Member    
Account Value [Line Items]    
Accumulated Value 10,702  
C000133805_ClassMember_AsOf_2019Member    
Account Value [Line Items]    
Accumulated Value 9,976  
C000133805_ClassMember_AsOf_2020Member    
Account Value [Line Items]    
Accumulated Value 8,939  
C000133805_ClassMember_AsOf_2021Member    
Account Value [Line Items]    
Accumulated Value 12,443  
C000133805_ClassMember_AsOf_2022Member    
Account Value [Line Items]    
Accumulated Value 15,883  
C000133805_ClassMember_AsOf_2023Member    
Account Value [Line Items]    
Accumulated Value 14,470  
C000133805_ClassMember_AsOf_2024Member    
Account Value [Line Items]    
Accumulated Value 13,954  
C000133805_ClassMember_AsOf_2025Member    
Account Value [Line Items]    
Accumulated Value 15,269  
C000133805_ClassMember_AsOf_2026Member    
Account Value [Line Items]    
Accumulated Value 19,706  
C000133805_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 Commodity Strategy Linked Index</span>
C000133805_1_AdditionalIndexMember_AsOf_2016Member    
Account Value [Line Items]    
Accumulated Value 10,000  
C000133805_1_AdditionalIndexMember_AsOf_2017Member    
Account Value [Line Items]    
Accumulated Value 10,077  
C000133805_1_AdditionalIndexMember_AsOf_2018Member    
Account Value [Line Items]    
Accumulated Value 10,352  
C000133805_1_AdditionalIndexMember_AsOf_2019Member    
Account Value [Line Items]    
Accumulated Value 9,797  
C000133805_1_AdditionalIndexMember_AsOf_2020Member    
Account Value [Line Items]    
Accumulated Value 8,614  
C000133805_1_AdditionalIndexMember_AsOf_2021Member    
Account Value [Line Items]    
Accumulated Value 12,084  
C000133805_1_AdditionalIndexMember_AsOf_2022Member    
Account Value [Line Items]    
Accumulated Value 15,374  
C000133805_1_AdditionalIndexMember_AsOf_2023Member    
Account Value [Line Items]    
Accumulated Value 14,162  
C000133805_1_AdditionalIndexMember_AsOf_2024Member    
Account Value [Line Items]    
Accumulated Value 13,429  
C000133805_1_AdditionalIndexMember_AsOf_2025Member    
Account Value [Line Items]    
Accumulated Value 14,734  
C000133805_1_AdditionalIndexMember_AsOf_2026Member    
Account Value [Line Items]    
Accumulated Value 18,904  
C000133805_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;">Bloomberg Commodity 3 Month Forward Total Return Index</span>
C000133805_2_AdditionalIndexMember_AsOf_2016Member    
Account Value [Line Items]    
Accumulated Value 10,000  
C000133805_2_AdditionalIndexMember_AsOf_2017Member    
Account Value [Line Items]    
Accumulated Value 10,250  
C000133805_2_AdditionalIndexMember_AsOf_2018Member    
Account Value [Line Items]    
Accumulated Value 10,750  
C000133805_2_AdditionalIndexMember_AsOf_2019Member    
Account Value [Line Items]    
Accumulated Value 10,237  
C000133805_2_AdditionalIndexMember_AsOf_2020Member    
Account Value [Line Items]    
Accumulated Value 9,671  
C000133805_2_AdditionalIndexMember_AsOf_2021Member    
Account Value [Line Items]    
Accumulated Value 13,744  
C000133805_2_AdditionalIndexMember_AsOf_2022Member    
Account Value [Line Items]    
Accumulated Value 18,015  
C000133805_2_AdditionalIndexMember_AsOf_2023Member    
Account Value [Line Items]    
Accumulated Value 17,196  
C000133805_2_AdditionalIndexMember_AsOf_2024Member    
Account Value [Line Items]    
Accumulated Value 16,736  
C000133805_2_AdditionalIndexMember_AsOf_2025Member    
Account Value [Line Items]    
Accumulated Value 18,294  
C000133805_2_AdditionalIndexMember_AsOf_2026Member    
Account Value [Line Items]    
Accumulated Value $ 23,489