v3.26.3
Shareholder Report
 6 Months Ended
Aug. 31, 2026
USD ($)
shares
Shareholder Report [Line Items]  
Document Type N-CSRS
Amendment Flag false
Registrant Name Fidelity Rutland Square Trust II
Entity Central Index Key 0001364924
Entity Investment Company Type N-1A
Document Period End Date Aug. 31, 2026
Strategic Advisers International Fund  
Shareholder Report [Line Items]  
Fund Name Strategic Advisers® International Fund
Class Name Strategic Advisers® International Fund
Trading Symbol FILFX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains information about Strategic Advisers® International Fund for the period March 1, 2026 to August 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
 
Strategic Advisers® International Fund 
$ 9 
0.18%
  
Expenses Paid, Amount $ 9
Expense Ratio, Percent 0.18%
Net Assets $ 29,186,553,666
Holdings Count | shares 1,045
Investment Company Portfolio Turnover 47.00%
Additional Fund Statistics [Text Block] Key Fund Statistics
(as of August 31, 2026)
 
KEY FACTS 
  
  
Fund Size
$29,186,553,666
  
Number of Holdings
1,045
  
Portfolio Turnover
47%
  
Holdings [Text Block]       MARKET SECTORS (% of Fund's net assets)     Financials 18.0   Industrials 12.8   Information Technology 8.5   Health Care 6.6   Consumer Discretionary 4.9   Materials 4.4   Consumer Staples 3.6   Energy 2.6   Communication Services 2.2   Utilities 1.7   Real Estate 0.6     Common Stocks 65.9 International Equity Funds 30.3 Preferred Stocks 0.0 Short-Term Investments and Net Other Assets (Liabilities) 3.8 ASSET ALLOCATION (% of Fund's net assets)     Common Stocks - 65.9                       International Equity Funds - 30.3          Preferred Stocks - 0.0                     Short-Term Investments and Net Other Assets (Liabilities) - 3.8   United States 39.2 Japan 13.6 United Kingdom 9.6 France 7.0 Germany 5.6 Netherlands 3.5 Italy 2.7 Switzerland 2.3 Spain 2.2 Others 14.3 GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets)     United States - 39.2                       Japan - 13.6                               United Kingdom - 9.6                       France - 7.0                               Germany - 5.6                              Netherlands - 3.5                          Italy - 2.7                                Switzerland - 2.3                          Spain - 2.2                                Others - 14.3                                 
Largest Holdings [Text Block] TOP HOLDINGS(% of Fund's net assets)     Fidelity SAI International Value Index Fund 7.3   Fidelity SAI International Low Volatility Index Fund 4.9   Artisan International Value Fund Investor Class 3.7   iShares MSCI Eurozone ETF 3.4   State Street Institutional U.S. Government Money Market Fund Premier Class 2.8   ASML Holding NV 2.0   Fidelity SAI Japan Stock Index Fund 1.8   WCM Focused International Growth Fund Investor Class 1.4   Fidelity Advisor Japan Fund - Class Z 1.4   Roche Holding AG 1.1     29.8  
Strategic Advisers Income Opportunities Fund  
Shareholder Report [Line Items]  
Fund Name Strategic Advisers® Income Opportunities Fund
Class Name Strategic Advisers® Income Opportunities Fund
Trading Symbol FPIOX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains information about Strategic Advisers® Income Opportunities Fund for the period March 1, 2026 to August 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
 
Strategic Advisers® Income Opportunities Fund 
$ 8 
0.16%
  
Expenses Paid, Amount $ 8
Expense Ratio, Percent 0.16%
Net Assets $ 1,763,225,678
Holdings Count | shares 1,414
Investment Company Portfolio Turnover 57.00%
Additional Fund Statistics [Text Block] Key Fund Statistics
(as of August 31, 2026)
 
KEY FACTS 
  
  
Fund Size
$1,763,225,678
  
Number of Holdings
1,414
  
Portfolio Turnover
57%
  
Holdings [Text Block]         Fixed-Income Funds 50.0 Corporate Bonds 40.8 Bank Loan Obligations 3.2 U.S. Treasury Obligations 1.8 Preferred Securities 1.2 Common Stocks 0.6 Preferred Stocks 0.2 Municipal Securities 0.1 Asset-Backed Securities 0.1 Short-Term Investments and Net Other Assets (Liabilities) 2.0 ASSET ALLOCATION (% of Fund's net assets)     Fixed-Income Funds - 50.0                  Corporate Bonds - 40.8                     Bank Loan Obligations - 3.2                U.S. Treasury Obligations - 1.8            Preferred Securities - 1.2                 Common Stocks - 0.6                        Preferred Stocks - 0.2                     Municipal Securities - 0.1                 Asset-Backed Securities - 0.1              Short-Term Investments and Net Other Assets (Liabilities) - 2.0  
Largest Holdings [Text Block] TOP HOLDINGS(% of Fund's net assets)     Artisan High Income Fund Investor Shares 13.4   BlackRock High Yield Portfolio Class K 12.6   Fidelity Capital & Income Fund 10.7   Eaton Vance Income Fund of Boston Class A 5.7   Vanguard High-Yield Corporate Fund Admiral Shares 4.5   NYLI MacKay High Yield Corporate Bond Fund Class A 3.1   US Treasury Notes 1.7   TransDigm Inc 0.7   NRG Energy Inc 0.7   CCO Holdings LLC / CCO Holdings Capital Corp 0.7     53.8  
Strategic Advisers Fidelity International Fund  
Shareholder Report [Line Items]  
Fund Name Strategic Advisers® Fidelity® International Fund
Class Name Strategic Advisers® Fidelity® International Fund
Trading Symbol FUSIX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains information about Strategic Advisers® Fidelity® International Fund for the period March 1, 2026 to August 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
 
Strategic Advisers® Fidelity® International Fund 
$ 8 
0.15%
  
Expenses Paid, Amount $ 8
Expense Ratio, Percent 0.15%
Net Assets $ 78,532,993,338
Holdings Count | shares 400
Investment Company Portfolio Turnover 68.00%
Additional Fund Statistics [Text Block] Key Fund Statistics
(as of August 31, 2026)
 
KEY FACTS 
  
  
Fund Size
$78,532,993,338
  
Number of Holdings
400
  
Portfolio Turnover
68%
  
Holdings [Text Block]       MARKET SECTORS (% of Fund's net assets)     Financials 17.6   Industrials 13.6   Information Technology 7.7   Health Care 4.5   Materials 4.5   Consumer Discretionary 3.9   Consumer Staples 2.8   Energy 1.9   Utilities 1.6   Communication Services 1.4   Real Estate 0.3     Common Stocks 59.7 International Equity Funds 32.3 Preferred Stocks 0.1 Domestic Equity Funds 0.0 Short-Term Investments and Net Other Assets (Liabilities) 7.9 ASSET ALLOCATION (% of Fund's net assets)     Common Stocks - 59.7                       International Equity Funds - 32.3          Preferred Stocks - 0.1                     Domestic Equity Funds - 0.0                Short-Term Investments and Net Other Assets (Liabilities) - 7.9   United States 45.6 Japan 13.1 United Kingdom 8.3 Germany 5.1 France 4.4 Netherlands 3.1 Spain 3.1 Italy 3.0 Switzerland 2.0 Others 12.3 GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets)     United States - 45.6                       Japan - 13.1                               United Kingdom - 8.3                       Germany - 5.1                              France - 4.4                               Netherlands - 3.1                          Spain - 3.1                                Italy - 3.0                                Switzerland - 2.0                          Others - 12.3                                 
Largest Holdings [Text Block] TOP HOLDINGS(% of Fund's net assets)     Fidelity SAI International Value Index Fund 15.1   Fidelity SAI International Index Fund 6.3   State Street Institutional U.S. Government Money Market Fund Premier Class 6.1   Fidelity SAI International Low Volatility Index Fund 5.6   Fidelity SAI International Quality Index Fund 2.1   ASML Holding NV 2.0   Banco Santander SA 1.5   Roche Holding AG 1.2   Fidelity SAI International Momentum Index Fund 1.1   Schneider Electric SE 1.1     42.1  
Strategic Advisers Emerging Markets Fund  
Shareholder Report [Line Items]  
Fund Name Strategic Advisers® Emerging Markets Fund
Class Name Strategic Advisers® Emerging Markets Fund
Trading Symbol FSAMX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains information about Strategic Advisers® Emerging Markets Fund for the period March 1, 2026 to August 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
 
Strategic Advisers® Emerging Markets Fund 
$ 15 
0.29%
  
Expenses Paid, Amount $ 15
Expense Ratio, Percent 0.29%
Net Assets $ 16,675,038,416
Holdings Count | shares 1,069
Investment Company Portfolio Turnover 65.00%
Additional Fund Statistics [Text Block] Key Fund Statistics
(as of August 31, 2026)
 
KEY FACTS 
  
  
Fund Size
$16,675,038,416
  
Number of Holdings
1,069
  
Portfolio Turnover
65%
  
Holdings [Text Block]       MARKET SECTORS (% of Fund's net assets)     Information Technology 29.2   Financials 13.3   Industrials 6.7   Consumer Discretionary 4.6   Communication Services 4.2   Materials 4.1   Energy 2.3   Health Care 2.3   Consumer Staples 1.1   Utilities 0.3   Real Estate 0.3     Common Stocks 67.9 International Equity Funds 27.5 Preferred Stocks 0.5 Domestic Equity Funds 0.0 Short-Term Investments and Net Other Assets (Liabilities) 4.1 ASSET ALLOCATION (% of Fund's net assets)     Common Stocks - 67.9                       International Equity Funds - 27.5          Preferred Stocks - 0.5                     Domestic Equity Funds - 0.0                Short-Term Investments and Net Other Assets (Liabilities) - 4.1   United States 32.1 Taiwan 18.7 China 15.0 Korea (South) 13.4 India 5.3 Brazil 2.5 South Africa 1.9 Mexico 1.5 Saudi Arabia 0.9 Others 8.7 GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets)     United States - 32.1                       Taiwan - 18.7                              China - 15.0                               Korea (South) - 13.4                       India - 5.3                                Brazil - 2.5                               South Africa - 1.9                         Mexico - 1.5                               Saudi Arabia - 0.9                         Others - 8.7                                  
Largest Holdings [Text Block] TOP HOLDINGS(% of Fund's net assets)     Fidelity SAI Emerging Markets Value Index Fund 13.3   Taiwan Semiconductor Manufacturing Co Ltd 10.5   Fidelity SAI Emerging Markets Low Volatility Index Fund 5.3   Samsung Electronics Co Ltd 5.3   SK Hynix Inc 3.5   Goldman Sachs Emerging Markets Equity Fund Institutional Class 3.3   State Street Institutional U.S. Government Money Market Fund Premier Class 3.1   Fidelity SAI Emerging Markets Index Fund 2.6   Tencent Holdings Ltd 2.5   MediaTek Inc 1.6     51.0  
Strategic Advisers Core Income Fund  
Shareholder Report [Line Items]  
Fund Name Strategic Advisers® Core Income Fund
Class Name Strategic Advisers® Core Income Fund
Trading Symbol FPCIX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains information about Strategic Advisers® Core Income Fund for the period March 1, 2026 to August 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
 
Strategic Advisers® Core Income Fund 
$ 3 
0.06%
  
Expenses Paid, Amount $ 3
Expense Ratio, Percent 0.06%
Net Assets $ 41,084,008,557
Holdings Count | shares 11,348
Investment Company Portfolio Turnover 207.00%
Additional Fund Statistics [Text Block] Key Fund Statistics
(as of August 31, 2026)
 
KEY FACTS 
  
  
Fund Size
$41,084,008,557
  
Number of Holdings
11,348
  
Portfolio Turnover
207%
  
Holdings [Text Block]   U.S. Government and U.S. Government Agency Obligations 33.5 AAA 4.2 AA 1.1 A 6.8 BBB 8.6 BB 1.7 B 0.2 CCC,CC,C 0.1 D 0.0 Not Rated 5.5 Equities 40.8 QUALITY DIVERSIFICATION (% of Fund's net assets)     U.S. Government and U.S. Government Agency Obligations - 33.5   AAA - 4.2                                  AA - 1.1                                   A - 6.8                                    BBB - 8.6                                  BB - 1.7                                   B - 0.2                                    CCC,CC,C - 0.1                             D - 0.0                                    Not Rated - 5.5                            Equities - 40.8                          Short-Term Investments and Net Other Assets (Liabilities) - (2.5)%   We have used ratings from Moody's Investors Service, Inc. Where Moody's® ratings are not available, we have used S&P® ratings. All ratings are as of the date indicated and do not reflect subsequent changes.         Fixed-Income Funds 40.8 U.S. Government Agency - Mortgage Securities 18.1 Corporate Bonds 16.0 U.S. Treasury Obligations 15.4 CMOs and Other Mortgage Related Securities 5.6 Asset-Backed Securities 4.8 Foreign Government and Government Agency Obligations 1.2 Preferred Securities 0.2 Bank Loan Obligations 0.2 Municipal Securities 0.1 Other Investments 0.1 Others 0.0 ASSET ALLOCATION (% of Fund's net assets)     Fixed-Income Funds - 40.8                  U.S. Government Agency - Mortgage Securities - 18.1   Corporate Bonds - 16.0                     U.S. Treasury Obligations - 15.4           CMOs and Other Mortgage Related Securities - 5.6   Asset-Backed Securities - 4.8              Foreign Government and Government Agency Obligations - 1.2   Preferred Securities - 0.2                 Bank Loan Obligations - 0.2                Municipal Securities - 0.1                 Other Investments - 0.1                    Others - 0.0                             Short-Term Investments and Net Other Assets (Liabilities) - (2.5)%   United States 93.1 Grand Cayman (UK Overseas Ter) 1.6 United Kingdom 1.0 Ireland 0.5 Canada 0.5 Germany 0.5 Mexico 0.4 France 0.3 Japan 0.3 Others 1.8 GEOGRAPHIC DIVERSIFICATION (% of Fund's net assets)     United States - 93.1                       Grand Cayman (UK Overseas Ter) - 1.6       United Kingdom - 1.0                       Ireland - 0.5                              Canada - 0.5                               Germany - 0.5                              Mexico - 0.4                               France - 0.3                               Japan - 0.3                                Others - 1.8                                  
Largest Holdings [Text Block] TOP HOLDINGS(% of Fund's net assets)     US Treasury Notes 9.3   Uniform Mortgage Backed Securities 6.9   Fidelity SAI Total Bond Fund 6.5   US Treasury Bonds 5.7   Fannie Mae Mortgage pass-thru certificates 5.2   PIMCO Mortgage Opportunities and Bond Fund Institutional Class 5.0   Voya Intermediate Bond Fund Class I 3.5   Freddie Mac Gold Pool 3.3   American Funds The Bond Fund of America Class F-2 3.2   PIMCO Income Fund Institutional Class 3.1     51.7