v3.26.1
Risk/Return Detail Data - StrategicAdvisersMunicipalBondFund-PRO - USD ($)
 12 Months Ended 60 Months Ended 108 Months Ended
Jul. 31, 2026
Jul. 31, 2026
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Jul. 31, 2026
Jul. 31, 2026
StrategicAdvisersTax-SensitiveShortDurationFund-PRO | Strategic Advisers Tax-Sensitive Short Duration Fund | Strategic Advisers Tax-Sensitive Short Duration Fund                        
Prospectus Line Items                        
Management Fees (as a percentage of Assets) [1] 0.32%                      
Distribution and Service (12b-1) Fees 0.00%                      
Other Expenses (as a percentage of Assets): 0.01%                      
Acquired Fund Fees and Expenses 0.02%                      
Expenses (as a percentage of Assets) [2] 0.35%                      
Fee Waiver or Reimbursement [1] (0.25%)                      
Net Expenses (as a percentage of Assets) [2] 0.10%                      
Expense Example, with Redemption, 1 Year $ 10                      
Expense Example, with Redemption, 3 Years 51                      
Expense Example, with Redemption, 5 Years 135                      
Expense Example, with Redemption, 10 Years $ 384                      
Annual Return, Inception Date Dec. 28, 2017                      
Average Annual Return, Label [Optional Text]   Return Before Taxes                    
Average Annual Return, Percent   3.62%                 2.20% 1.98% [3]
Annual Return [Percent]     3.62% 3.47% 3.83% (0.09%) 0.24% 1.31% 2.10% 1.50%    
StrategicAdvisersTax-SensitiveShortDurationFund-PRO | Strategic Advisers Tax-Sensitive Short Duration Fund                        
Prospectus Line Items                        
Risk/Return [Heading] Fund Summary Fund: Strategic Advisers® Tax-Sensitive Short Duration Fund                      
Objective [Heading] Investment Objective                      
Objective, Primary [Text Block]  Strategic Advisers® Tax-Sensitive Short Duration Fund seeks to provide a high level of after-tax income consistent with preservation of capital.                      
Expense Heading [Optional Text] Fee Table                      
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund.                      
Shareholder Fees Caption [Optional Text] Shareholder fees                      
Shareholder Fee, Other $ 0                      
Operating Expenses Caption [Optional Text] Annual Operating Expenses                      
Fee Waiver or Reimbursement over Assets, Date of Termination September 30, 2028                      
Portfolio Turnover [Heading] Portfolio Turnover                      
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of affiliated mutual funds but may incur transaction costs when buying or selling non-affiliated funds and other types of securities (including Exchange Traded Funds (ETFs)) directly (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 64% of the average value of its portfolio.                      
Portfolio Turnover, Rate 64.00%                      
Expenses Not Correlated to Ratio Due to Acquired Fund Fees [Text] Differs from the ratios of expenses to average net assets in the Financial Highlights section of the prospectus because of acquired fund fees and expenses.                      
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:                      
Strategy [Heading] Principal Investment Strategies                      
Strategy Narrative [Text Block] Normally investing primarily in U.S. dollar-denominated municipal money market securities and high quality investment-grade municipal debt securities whose interest is exempt from federal income tax (the "municipal strategy"). The Adviser may invest all of the fund's assets in municipal securities whose interest is subject to the federal alternative minimum tax.Potentially investing in taxable money market securities when after-tax yields are viewed as advantageous, taking into account the highest federal tax rates applicable to investment income of individuals (together with the municipal strategy, the "tax-sensitive" strategy) or for liquidity purposes.Normally maintaining a dollar-weighted average maturity of three years or less.Allocating assets across different market sectors and maturities.Potentially investing more than 25% of total assets in municipal securities that finance similar types of projects.Engaging in transactions that have a leveraging effect on the fund, including investments in derivatives - such as swaps (interest rate, total return, and credit default) and futures contracts - and forward-settling securities, to adjust the fund's risk exposure.Implementing investment strategies by investing directly in securities through one or more managers (sub-advisers) or indirectly in securities through one or more other funds, referred to as underlying funds, which in turn invest directly in securities (as described below).Allocating assets among affiliated funds (i.e., Fidelity® funds, including mutual funds and ETFs), non-affiliated funds and non-affiliated ETFs.Allocating assets among underlying funds and sub-advisers with reference to the interest rate risk of the Bloomberg Municipal Bond 1 Year (1-2 Y) Index (25%) and the iMoneyNetSM All Tax-Free National Retail Money Market Funds Average (75%).Allocating assets among sub-advisers and underlying funds using proprietary fundamental and quantitative research, considering factors including, but not limited to, performance in different market environments, manager experience and investment style, management company infrastructure, costs, asset size, and portfolio turnover.Investing in lower-quality debt securities (those of less than investment-grade quality, also referred to as high yield debt securities or junk bonds).Analyzing the credit quality of the issuer, the issuer's potential for success, the credit, currency and economic risks of the security and its issuer, security-specific features, current and potential future valuation, and trading opportunities to select investments. Pursuant to an exemptive order granted by the Securities and Exchange Commission (SEC), Strategic Advisers LLC (Strategic Advisers) is permitted, subject to the approval of the Board of Trustees, to enter into new or amended sub-advisory agreements with one or more unaffiliated sub-advisers without obtaining shareholder approval of such agreements. Subject to oversight by the Board of Trustees, Strategic Advisers has the ultimate responsibility to oversee the fund's sub-advisers and recommend their hiring, termination, and replacement. In the event the Board of Trustees approves a sub-advisory agreement with a new unaffiliated sub-adviser, shareholders will be provided with information about the new sub-adviser and sub-advisory agreement.                      
Bar Chart and Performance Table [Heading] Performance                      
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index, a hypothetical composite of market indexes, and an additional index over various periods of time. The hypothetical composite of market indexes and additional index have characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance. Visit www.fidelity.com for more recent performance information.                      
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index, a hypothetical composite of market indexes, and an additional index over various periods of time.                      
Performance Availability Website Address [Text] www.fidelity.com                      
Performance Past Does Not Indicate Future [Text] Past performance (before and after taxes) is not an indication of future performance.                      
Bar Chart [Heading] Year-by-Year Returns                      
Year to Date Return, Label [Optional Text]    Year-to-Date Return                      
Bar Chart, Year to Date Return, Date Jun. 30, 2026                      
Bar Chart, Year to Date Return 1.49%                      
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return                      
Highest Quarterly Return, Date Dec. 31, 2023                      
Highest Quarterly Return 1.96%                      
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return                      
Lowest Quarterly Return, Date Mar. 31, 2022                      
Lowest Quarterly Return (0.99%)                      
Performance Table Heading Average Annual Returns                      
Performance Table Uses Highest Federal Rate After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes.                      
Performance Table Explanation after Tax Higher Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.                      
Performance Table Narrative After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. Actual after-tax returns may differ depending on your individual circumstances. Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.                      
StrategicAdvisersTax-SensitiveShortDurationFund-PRO | Strategic Advisers Tax-Sensitive Short Duration Fund | After Taxes on Distributions | Strategic Advisers Tax-Sensitive Short Duration Fund                        
Prospectus Line Items                        
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions                    
Average Annual Return, Percent   3.58%                 2.15% 1.93% [3]
StrategicAdvisersTax-SensitiveShortDurationFund-PRO | Strategic Advisers Tax-Sensitive Short Duration Fund | After Taxes on Distributions and Sales | Strategic Advisers Tax-Sensitive Short Duration Fund                        
Prospectus Line Items                        
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions and Sale of Fund Shares                    
Average Annual Return, Percent   3.41%                 2.14% 1.92% [3]
StrategicAdvisersTax-SensitiveShortDurationFund-PRO | Strategic Advisers Tax-Sensitive Short Duration Fund | IXYDZ                        
Prospectus Line Items                        
Average Annual Return, Label [Optional Text]   Strategic Advisers Tax Sensitive Short Duration Composite Index℠                    
Average Annual Return, Percent   3.00%                 2.08% 1.83%
StrategicAdvisersTax-SensitiveShortDurationFund-PRO | Strategic Advisers Tax-Sensitive Short Duration Fund | LB319                        
Prospectus Line Items                        
Average Annual Return, Label [Optional Text]   Bloomberg Municipal Bond 1 Year (1-2 Y) Index                    
Average Annual Return, Percent   3.47%                 1.73% 1.83%
StrategicAdvisersTax-SensitiveShortDurationFund-PRO | Strategic Advisers Tax-Sensitive Short Duration Fund | LB015                        
Prospectus Line Items                        
Average Annual Return, Label [Optional Text]   Bloomberg Municipal Bond Index                    
Average Annual Return, Percent   4.25%                 0.80% 2.23%
StrategicAdvisersMunicipalBondFund-PRO | Strategic Advisers Municipal Bond Fund | Strategic Advisers Municipal Bond Fund                        
Prospectus Line Items                        
Management Fees (as a percentage of Assets) [4] 0.33%                      
Distribution and Service (12b-1) Fees 0.00%                      
Other Expenses (as a percentage of Assets): 0.00%                      
Acquired Fund Fees and Expenses 0.11%                      
Expenses (as a percentage of Assets) [5] 0.44%                      
Fee Waiver or Reimbursement [4] (0.25%)                      
Net Expenses (as a percentage of Assets) [5] 0.19%                      
Expense Example, with Redemption, 1 Year $ 19                      
Expense Example, with Redemption, 3 Years 80                      
Expense Example, with Redemption, 5 Years 186                      
Expense Example, with Redemption, 10 Years $ 496                      
Annual Return, Inception Date Jun. 17, 2021                      
Average Annual Return, Label [Optional Text]   Return Before Taxes                    
Average Annual Return, Percent   3.80%                 0.61% [6]  
Annual Return [Percent]     3.80% 2.98% 7.13% (10.58%)            
StrategicAdvisersMunicipalBondFund-PRO | Strategic Advisers Municipal Bond Fund                        
Prospectus Line Items                        
Risk/Return [Heading] Fund Summary Fund: Strategic Advisers® Municipal Bond Fund                      
Objective [Heading] Investment Objective                      
Objective, Primary [Text Block] Strategic Advisers® Municipal Bond Fund seeks to provide a high current yield exempt from federal income tax.                      
Expense Heading [Optional Text] Fee Table                      
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund.                      
Shareholder Fees Caption [Optional Text] Shareholder fees                      
Shareholder Fee, Other $ 0                      
Operating Expenses Caption [Optional Text] Annual Operating Expenses                      
Fee Waiver or Reimbursement over Assets, Date of Termination September 30, 2028                      
Portfolio Turnover [Heading] Portfolio Turnover                      
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of affiliated mutual funds but may incur transaction costs when buying or selling non-affiliated funds and other types of securities (including Exchange Traded Funds (ETFs)) directly (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 24% of the average value of its portfolio.                      
Portfolio Turnover, Rate 24.00%                      
Expenses Not Correlated to Ratio Due to Acquired Fund Fees [Text] Differs from the ratios of expenses to average net assets in the Financial Highlights section of the prospectus because of acquired fund fees and expenses.                      
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:                      
Strategy [Heading] Principal Investment Strategies                      
Strategy Narrative [Text Block] Normally investing at least 80% of assets in municipal securities whose interest is exempt from federal income tax. The municipal securities in which the fund invests are normally investment-grade (those of medium and high quality). Municipal debt securities are issued to raise money for a variety of public and private purposes, including general financing for state and local governments, financing for eligible non-profit organizations, or financing for a specific project or public facility. Municipal debt securities in which the fund invests include securities issued by U.S. territories and possessions, general obligation bonds of municipalities, local or state governments, project or revenue-specific bonds, or pre-refunded or escrowed bonds, municipal money market securities, and synthetic securities. Municipal securities usually pay a fixed, variable, or floating rate of interest, and must repay the amount borrowed, usually at the maturity of the security. Municipal debt securities also include shares of underlying funds (including mutual funds and ETFs) that invest at least 80% of assets in municipal debt securities. Investment grade securities in which the fund invests include securities or issuers rated at least BBB- or its equivalent by at least one nationally recognized statistical ratings organization (NRSRO), or, if unrated, determined by the Adviser to be of comparable quality. Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Normally investing primarily in investment-grade municipal securities.Allocating assets across different market sectors and maturities.Potentially investing more than 25% of total assets in municipal securities that finance similar types of projects.Implementing investment strategies by investing directly in securities through one or more managers (sub-advisers) or indirectly in securities through one or more other funds, referred to as underlying funds, which in turn invest directly in securities (as described below).Allocating assets among affiliated funds (i.e., Fidelity® funds, including mutual funds and ETFs), non-affiliated funds and non-affiliated ETFs.Allocating assets among sub-advisers and underlying funds using proprietary fundamental and quantitative research, considering factors including, but not limited to, performance in different market environments, manager experience and investment style, management company infrastructure, costs, asset size, and portfolio turnover.Investing up to 30% in lower-quality debt securities (those of less than investment-grade quality, also referred to as high yield debt securities or junk bonds).Analyzing the credit quality of the issuer, the issuer's potential for success, the credit, currency and economic risks of the security and its issuer, security-specific features, current and potential future valuation, and trading opportunities to select investments. Pursuant to an exemptive order granted by the Securities and Exchange Commission (SEC), Strategic Advisers LLC (Strategic Advisers) is permitted, subject to the approval of the Board of Trustees, to enter into new or amended sub-advisory agreements with one or more unaffiliated sub-advisers without obtaining shareholder approval of such agreements. Subject to oversight by the Board of Trustees, Strategic Advisers has the ultimate responsibility to oversee the fund's sub-advisers and recommend their hiring, termination, and replacement. In the event the Board of Trustees approves a sub-advisory agreement with a new unaffiliated sub-adviser, shareholders will be provided with information about the new sub-adviser and sub-advisory agreement.                      
Bar Chart and Performance Table [Heading] Performance                      
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index over various periods of time. The index description appears in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance. Visit www.fidelity.com for more recent performance information.                      
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index over various periods of time.                      
Performance Availability Website Address [Text] www.fidelity.com                      
Performance Past Does Not Indicate Future [Text] Past performance (before and after taxes) is not an indication of future performance.                      
Bar Chart [Heading] Year-by-Year Returns                      
Year to Date Return, Label [Optional Text]    Year-to-Date Return                      
Bar Chart, Year to Date Return, Date Jun. 30, 2026                      
Bar Chart, Year to Date Return 2.89%                      
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return                      
Highest Quarterly Return, Date Dec. 31, 2023                      
Highest Quarterly Return 7.60%                      
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return                      
Lowest Quarterly Return, Date Mar. 31, 2022                      
Lowest Quarterly Return (6.55%)                      
Performance Table Heading Average Annual Returns                      
Performance Table Uses Highest Federal Rate After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes.                      
Performance Table Explanation after Tax Higher Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.                      
Performance Table Narrative After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. Actual after-tax returns may differ depending on your individual circumstances. Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.                      
StrategicAdvisersMunicipalBondFund-PRO | Strategic Advisers Municipal Bond Fund | After Taxes on Distributions | Strategic Advisers Municipal Bond Fund                        
Prospectus Line Items                        
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions                    
Average Annual Return, Percent   3.80%                 0.61% [6]  
StrategicAdvisersMunicipalBondFund-PRO | Strategic Advisers Municipal Bond Fund | After Taxes on Distributions and Sales | Strategic Advisers Municipal Bond Fund                        
Prospectus Line Items                        
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions and Sale of Fund Shares                    
Average Annual Return, Percent   3.87%                 1.20% [6]  
StrategicAdvisersMunicipalBondFund-PRO | Strategic Advisers Municipal Bond Fund | LB015                        
Prospectus Line Items                        
Average Annual Return, Label [Optional Text]   Bloomberg Municipal Bond Index                    
Average Annual Return, Percent   4.25%                 0.63%  
Document Type 497                      
Registrant Name Fidelity Rutland Square Trust II                      
[1] AStrategic Advisers LLC (Strategic Advisers) has contractually agreed that the fund's maximum aggregate annual management fee will not exceed 0.55% of the fund's average daily net assets. In addition, Strategic Advisers has contractually agreed to waive a portion of the fund's management fee in an amount equal to 0.25% of the fund's average daily net assets. This arrangement will remain in effect through September 30, 2028, and neither Strategic Advisers nor any of its affiliates retain the ability to be repaid with respect to this arrangement. Strategic Advisers may not terminate this arrangement without the approval of the Board of Trustees.
[2] BDiffers from the ratios of expenses to average net assets in the Financial Highlights section of the prospectus because of acquired fund fees and expenses.
[3] AFrom December 28, 2017.
[4] AStrategic Advisers LLC (Strategic Advisers) has contractually agreed that the fund's maximum aggregate annual management fee will not exceed 0.60% of the fund's average daily net assets. In addition, Strategic Advisers has contractually agreed to waive a portion of the fund's management fee in an amount equal to 0.25% of the fund's average daily net assets. This arrangement will remain in effect through September 30, 2028, and neither Strategic Advisers nor any of its affiliates retain the ability to be repaid with respect to this arrangement. Strategic Advisers may not terminate this arrangement without the approval of the Board of Trustees.
[5] BDiffers from the ratios of expenses to average net assets in the Financial Highlights section of the prospectus because of acquired fund fees and expenses.
[6] AFrom June 17, 2021.