v3.26.1
Shareholder Report
 6 Months Ended
Jan. 31, 2026
USD ($)
shares
Shareholder Report [Line Items]  
Document Type N-CSRS
Amendment Flag false
Registrant Name Fidelity Oxford Street Trust II
Entity Central Index Key 0001586462
Entity Investment Company Type N-1A
Document Period End Date Jan. 31, 2026
Fidelity Commodity Strategy Central Fund  
Shareholder Report [Line Items]  
Fund Name Fidelity® Commodity Strategy Central Fund
Class Name Fidelity® Commodity Strategy Central Fund
No Trading Symbol Flag true
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains information about Fidelity® Commodity Strategy Central Fund for the period August 1, 2025 to January 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.
Additional Information Phone Number 1-800-544-8544
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® Commodity Strategy Central Fund 
$ 0 A
0.01%
  
A Amount represents less than $.50
 
Expenses Paid, Amount $ 0
Expense Ratio, Percent 0.01%
Net Assets $ 527,525,780
Holdings Count | shares 55
Investment Company Portfolio Turnover 0.00%
Additional Fund Statistics [Text Block] Key Fund Statistics
(as of January 31, 2026)
 
KEY FACTS 
  
  
Fund Size
$527,525,780
  
Number of Holdings
55
  
Portfolio Turnover
0%
  
Holdings [Text Block] Industrial Metals 31.8 Energy 27.0 Agriculture 21.9 Precious Metals 14.9 Livestock 4.4 COMMODITY SECTOR DIVERSIFICATION (% of Fund's net assets)   Industrial Metals - 31.8                   Energy - 27.0                              Agriculture - 21.9                         Precious Metals - 14.9                     Livestock - 4.4                            DERIVATIVE EXPOSURE (% of Fund's net assets)     Futures Contracts 68.1   Swaps 51.2           Futures Contracts 31.0 Swaps 23.3 Short-Term Investments and Net Other Assets (Liabilities) 45.7 ASSET ALLOCATION (% of Fund's total exposure)     Futures Contracts - 31.0                   Swaps - 23.3                               Short-Term Investments and Net Other Assets (Liabilities) - 45.7