The fund pays transaction costs, such as commissions, when it buys and sells securities (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 38 % of the average value of its portfolio.

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 Narrative [Text Block]

Normally investing at least 80% of assets in corporate bonds and other corporate debt securities and repurchase agreements for those securities. Corporate debt securities are bonds and other debt securities issued by corporations and other business structures to borrow money. The issuer usually pays a fixed, variable, or floating rate of interest, and must repay the amount borrowed, usually at the maturity of the security. Corporate debt securities include repurchase agreements with corporate counterparties and other securities, such as hybrids and synthetic securities, believed to have corporate debt-like characteristics, (e.g., securities classified as Tier 2 Regulatory capital, securities that rank above share capital in an insolvency waterfall, securities with maturity dates and non-cancellable interest payment structures). A repurchase agreement is an agreement to buy a security at one price and a simultaneous agreement to sell it back at an agreed-upon price. 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 corporate debt securities and repurchase agreements for those securities. Managing the fund to have similar overall interest rate risk to the Bloomberg U.S. Credit Bond Index. Investing in domestic and foreign issuers. Analyzing the credit quality of the issuer, security-specific features, current and potential future valuation, and trading opportunities to select investments. Investing in lower-quality debt securities (those of less than investment-grade quality, also referred to as high yield debt securities or junk bonds). 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), options, and futures contracts - and forward-settling securities, to adjust the fund's risk exposure.

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 and an additional index over various periods of time. The additional index has 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 Availability Website Address [Text]

www.fidelity.com

Bar Chart [Heading]

Year-by-Year Returns

Bar Chart, Year to Date Return, Date

Sep. 30, 2026

Highest Quarterly Return, Label [Optional Text]

Highest Quarter Return

Highest Quarterly Return

10.71%

Lowest Quarterly Return, Date

Jun. 30, 2022

Performance Table Heading

Average Annual Returns

Performance Table Not Relevant to Tax Deferred

The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).

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. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). 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.

Prospectus Line Items

Average Annual Return, Percent

6.14%

(1.34%)

2.13%

Prospectus Line Items

Average Annual Return, Percent

4.76%

(0.55%)

2.12%

Prospectus Line Items

Average Annual Return, Percent

7.30%

(0.36%)

2.01%

Prospectus Line Items

Average Annual Return, Percent

7.83%

(0.05%)

3.15%

Prospectus Line Items

Distribution and Service (12b-1) Fees

0.00%

Expenses (as a percentage of Assets)

0.36%

Expense Example, with Redemption, 3 Years

116

Expense Example, with Redemption, 10 Years

$ 456

Average Annual Return, Label [Optional Text]

Return Before Taxes

Annual Return [Percent]

7.25%

1.40%

6.42%

(13.60%)

Prospectus Line Items

Objective [Heading]

Investment Objective

Expense Heading [Optional Text]

Fee Table

Shareholder Fees Caption [Optional Text]

Shareholder fees

Operating Expenses Caption [Optional Text]

Annual Operating Expenses

Portfolio Turnover [Text Block]

The fund pays transaction costs, such as commissions, when it buys and sells securities (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 211 % of the average value of its portfolio.

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 Narrative [Text Block]

Normally investing at least 80% of assets in investment-grade debt securities (those of medium and high quality) of all types and repurchase agreements for those securities. Debt securities are used by issuers to borrow money. The issuer usually pays a fixed, variable, or floating rate of interest, and must repay the amount borrowed, usually at the maturity of the security. Debt securities include corporate bonds, government securities (including Treasury securities), repurchase agreements, money market securities, mortgage and other asset-backed securities, loans and loan participations, and other securities, such as hybrids and synthetic securities, believed to have debt-like characteristics (e.g., securities classified as Tier 2 Regulatory capital, securities that rank above share capital in an insolvency waterfall, securities with maturity dates and non-cancellable interest payment structures). 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. A repurchase agreement is an agreement to buy a security at one price and a simultaneous agreement to sell it back at an agreed-upon price. 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. Managing the fund to have similar overall interest rate risk to the Bloomberg U.S. Aggregate Bond Index. Allocating assets across different market sectors and maturities. Investing in domestic and foreign issuers. Analyzing the credit quality of the issuer, security-specific features, current and potential future valuation, and trading opportunities to select investments. Investing in lower-quality debt securities (those of less than investment-grade quality, also referred to as high yield debt securities or junk bonds). 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), options, and futures contracts - and forward-settling securities, to adjust the fund's risk exposure.

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 Availability Website Address [Text]

www.fidelity.com

Bar Chart [Heading]

Year-by-Year Returns

Bar Chart, Year to Date Return, Date

Sep. 30, 2026

Highest Quarterly Return, Label [Optional Text]

Highest Quarter Return

Highest Quarterly Return

6.97%

Lowest Quarterly Return, Date

Mar. 31, 2022

Performance Table Heading

Average Annual Returns

Performance Table Not Relevant to Tax Deferred

The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).

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. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). 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.

Prospectus Line Items

Average Annual Return, Percent

5.43%

(1.03%)

^[1]

Prospectus Line Items

Average Annual Return, Percent

4.26%

(0.35%)

^[1]

Prospectus Line Items

Average Annual Return, Percent

7.30%

0.09%

Prospectus Line Items

Distribution and Service (12b-1) Fees

0.00%

Expenses (as a percentage of Assets)

0.36%

Expense Example, with Redemption, 3 Years

116

Expense Example, with Redemption, 10 Years

$ 456

Average Annual Return, Label [Optional Text]

Return Before Taxes

Annual Return [Percent]

8.39%

2.04%

5.41%

(12.57%)

Prospectus Line Items

Objective [Heading]

Investment Objective

Expense Heading [Optional Text]

Fee Table

Shareholder Fees Caption [Optional Text]

Shareholder fees

Operating Expenses Caption [Optional Text]

Annual Operating Expenses

Portfolio Turnover [Text Block]

The fund pays transaction costs, such as commissions, when it buys and sells securities (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 620 % of the average value of its portfolio.

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 Narrative [Text Block]

Normally investing at least 80% of assets in investment-grade securitized debt securities (those of medium and high quality) and repurchase agreements for those securities. Securitized debt securities are interests in pools of mortgages, loans, receivables, or other assets, and include such instruments as mortgage-backed securities, commercial mortgage-backed securities, and other asset-backed securities that are issued by the U.S. Government, its agencies or instrumentalities, foreign governments, financial institutions, trusts and corporations. Payment of principal or interest on securitized debt instruments generally depends on the cash flows generated by the underlying assets and may be supported by letters of credit, surety bonds, or other credit enhancements. 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. A repurchase agreement is an agreement to buy a security at one price and a simultaneous agreement to sell it back at an agreed-upon price. 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. Investing in U.S. Government securities issued by entities that are chartered or sponsored by Congress but whose securities are neither issued nor guaranteed by the U.S. Treasury. Managing the fund to have similar overall interest rate risk to the Bloomberg U.S. Securitized Index. Allocating assets across different market sectors and maturities. Investing in domestic and foreign issuers. Analyzing the credit quality of the issuer, security-specific features, current and potential future valuation, and trading opportunities to select investments. Investing in lower-quality debt securities (those of less than investment-grade quality, also referred to as high yield debt securities or junk bonds). 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), options, and futures contracts - and forward-settling securities, to adjust the fund's risk exposure.

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 and an additional index over various periods of time. The additional index has 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 Availability Website Address [Text]

www.fidelity.com

Bar Chart [Heading]

Year-by-Year Returns

Bar Chart, Year to Date Return, Date

Sep. 30, 2026

Highest Quarterly Return, Label [Optional Text]

Highest Quarter Return

Highest Quarterly Return

7.49%

Lowest Quarterly Return, Date

Sep. 30, 2022

Performance Table Heading

Average Annual Returns

Performance Table Not Relevant to Tax Deferred

The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).

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. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). 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.

Prospectus Line Items

Average Annual Return, Percent

6.53%

(0.78%)

^[2]

Prospectus Line Items

Average Annual Return, Percent

4.94%

(0.25%)

^[2]

Prospectus Line Items

Average Annual Return, Percent

7.30%

0.09%

Prospectus Line Items

Average Annual Return, Percent

8.49%

0.32%

Prospectus Line Items

Distribution and Service (12b-1) Fees

0.00%

Expenses (as a percentage of Assets)

0.25%

Expense Example, with Redemption, 3 Years

80

Expense Example, with Redemption, 10 Years

$ 318

Average Annual Return, Percent

6.71%

2.03%

2.65%

Risk/Return [Heading]

Fund Summary Fund: Fidelity® Limited Term Bond ETF

Objective, Primary [Text Block]

Fidelity® Limited Term Bond ETF seeks to provide a high rate of income.

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. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.

Shareholder Fee, Other

$ 0

Portfolio Turnover [Heading]

Portfolio Turnover

Portfolio Turnover, Rate

77.00%

Strategy [Heading]

Principal Investment Strategies

Bar Chart and Performance Table [Heading]

Performance

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, an additional index, and a hypothetical composite of market indexes over various periods of time.

Performance Past Does Not Indicate Future [Text]

Past performance (before and after taxes) is not an indication of future performance.

Year to Date Return, Label [Optional Text]

Year-to-Date Return

Bar Chart, Year to Date Return

(0.05%)

Highest Quarterly Return, Date

Jun. 30, 2020

Lowest Quarterly Return, Label [Optional Text]

Lowest Quarter Return

Lowest Quarterly Return

(3.67%)

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.

Average Annual Return, Label [Optional Text]

Return After Taxes on Distributions

Average Annual Return, Label [Optional Text]

Return After Taxes on Distributions and Sale of Fund Shares

Average Annual Return, Label [Optional Text]

Bloomberg U.S. Aggregate Bond Index

Average Annual Return, Label [Optional Text]

Bloomberg U.S. 1-5 Year Government/Credit Bond Index

Average Annual Return, Label [Optional Text]

Fidelity Limited Term Composite Index℠

Management Fees (as a percentage of Assets)

0.36%

Other Expenses (as a percentage of Assets):

0.00%

Expense Example, with Redemption, 1 Year

$ 37

Expense Example, with Redemption, 5 Years

202

Average Annual Return, Label [Optional Text]

Return Before Taxes

Annual Return [Percent]

7.58%

2.36%

6.84%

(12.73%)

(0.35%)

9.51%

9.90%

(0.67%)

4.07%

6.64%

Prospectus Line Items

Objective [Heading]

Investment Objective

Expense Heading [Optional Text]

Fee Table

Shareholder Fees Caption [Optional Text]

Shareholder fees

Operating Expenses Caption [Optional Text]

Annual Operating Expenses

Portfolio Turnover [Text Block]

The fund pays transaction costs, such as commissions, when it buys and sells securities (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 157 % of the average value of its portfolio.

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 Narrative [Text Block]

Normally investing at least 80% of assets in debt securities of all types and repurchase agreements for those securities. Debt securities are used by issuers to borrow money. The issuer usually pays a fixed, variable, or floating rate of interest, and must repay the amount borrowed, usually at the maturity of the security. Debt securities include corporate bonds, government securities (including Treasury securities), repurchase agreements, money market securities, mortgage and other asset-backed securities, loans and loan participations, and other securities, such as hybrids and synthetic securities, believed to have debt-like characteristics (e.g., securities classified as Tier 2 Regulatory capital, securities that rank above share capital in an insolvency waterfall, securities with maturity dates and non-cancellable interest payment structures). A repurchase agreement is an agreement to buy a security at one price and a simultaneous agreement to sell it back at an agreed-upon price. 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. Allocating assets across investment-grade, high yield, and emerging markets debt securities. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Investing up to 20% of assets in lower-quality debt securities (those of less than investment-grade quality, also referred to as high yield debt securities or junk bonds). Managing the fund to have similar overall interest rate risk to the Bloomberg U.S. Aggregate Bond Index. Investing in domestic and foreign issuers. Allocating assets across different asset classes, market sectors, and maturities. 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. 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), options, and futures contracts - and forward-settling securities, to adjust the fund's risk exposure.

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 Availability Website Address [Text]

www.fidelity.com

Bar Chart [Heading]

Year-by-Year Returns

Bar Chart, Year to Date Return, Date

Sep. 30, 2026

Highest Quarterly Return, Label [Optional Text]

Highest Quarter Return

Highest Quarterly Return

6.85%

Lowest Quarterly Return, Date

Jun. 30, 2022

Performance Table Heading

Average Annual Returns

Performance Table Not Relevant to Tax Deferred

The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).

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. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). 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.

Prospectus Line Items

Average Annual Return, Percent

5.53%

(1.05%)

1.69%

Prospectus Line Items

Average Annual Return, Percent

4.45%

(0.31%)

1.78%

Prospectus Line Items

Average Annual Return, Percent

7.30%

(0.36%)

2.01%

Prospectus Line Items

Distribution and Service (12b-1) Fees

0.00%

Expenses (as a percentage of Assets)

0.55%

Expense Example, with Redemption, 3 Years

176

Expense Example, with Redemption, 10 Years

$ 689

Average Annual Return, Label [Optional Text]

Return Before Taxes

Annual Return [Percent]

8.37%

1.67%

Prospectus Line Items

Objective [Heading]

Investment Objective

Expense Heading [Optional Text]

Fee Table

Shareholder Fees Caption [Optional Text]

Shareholder fees

Operating Expenses Caption [Optional Text]

Annual Operating Expenses

Portfolio Turnover [Text Block]

The fund pays transaction costs, such as commissions, when it buys and sells securities (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 48 % of the average value of its portfolio.

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 Narrative [Text Block]

Normally investing at least 80% of assets in debt securities of all types and repurchase agreements for those securities. Debt securities are used by issuers to borrow money. The issuer usually pays a fixed, variable, or floating rate of interest, and must repay the amount borrowed, usually at the maturity of the security. Debt securities include corporate bonds, government securities (including Treasury securities), repurchase agreements, money market securities, mortgage and other asset-backed securities, loans and loan participations, and other securities, such as hybrids and synthetic securities, believed to have debt-like characteristics (e.g., securities classified as Tier 2 Regulatory capital, securities that rank above share capital in an insolvency waterfall, securities with maturity dates and non-cancellable interest payment structures). A repurchase agreement is an agreement to buy a security at one price and a simultaneous agreement to sell it back at an agreed-upon price. 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. Allocating assets across the full spectrum of the debt market, including investment-grade (those of medium and high quality), high yield and emerging markets debt securities across different maturities. In addition to the debt securities listed above, investments also will normally include lower-quality debt securities (those of less than investment-grade quality, also referred to as high yield debt securities or junk bonds), investment-grade securitized debt securities (those of medium and high quality), floating rate loans and other floating rate securities, inflation-protected debt securities, preferred securities, contingent convertible securities, and securities of foreign issuers, including securities of issuers located in emerging markets. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Investing in both U.S. dollar-denominated and non-U.S. dollar-denominated securities, and generally hedging the fund's foreign currency exposures utilizing forward foreign currency exchange contracts. Investing in collateralized loan obligations (CLO). Analyzing the credit quality of the issuer, security-specific features, current and potential future valuation, and trading opportunities to select investments. 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), options, and futures contracts - and forward-settling securities, to adjust the fund's risk exposure.

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 Availability Website Address [Text]

www.fidelity.com

Bar Chart [Heading]

Year-by-Year Returns

Bar Chart, Year to Date Return, Date

Sep. 30, 2026

Highest Quarterly Return, Label [Optional Text]

Highest Quarter Return

Highest Quarterly Return

5.29%

Lowest Quarterly Return, Date

Dec. 31, 2024

Performance Table Heading

Average Annual Returns

Performance Table Not Relevant to Tax Deferred

The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).

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. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). 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.

Prospectus Line Items

Average Annual Return, Percent

6.16%

2.60%

^[3]

Prospectus Line Items

Average Annual Return, Percent

4.92%

2.67%

^[3]

Prospectus Line Items

Average Annual Return, Percent

7.30%

3.68%

Prospectus Line Items

Distribution and Service (12b-1) Fees

0.00%

Expenses (as a percentage of Assets)

0.20%

Expense Example, with Redemption, 3 Years

64

Expense Example, with Redemption, 10 Years

$ 255

Average Annual Return, Label [Optional Text]

Return Before Taxes

Annual Return [Percent]

4.79%

Prospectus Line Items

Objective [Heading]

Investment Objective

Expense Heading [Optional Text]

Fee Table

Shareholder Fees Caption [Optional Text]

Shareholder fees

Operating Expenses Caption [Optional Text]

Annual Operating Expenses

Portfolio Turnover [Text Block]

The fund pays transaction costs, such as commissions, when it buys and sells securities (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 60 % of the average value of its portfolio.

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 Narrative [Text Block]

Normally investing at least 80% of assets in investment-grade debt securities (those of medium and high quality) of all types and repurchase agreements for those securities. Debt securities are used by issuers to borrow money. The issuer usually pays a fixed, variable, or floating rate of interest, and must repay the amount borrowed, usually at the maturity of the security. Debt securities include corporate bonds, government securities (including Treasury securities), repurchase agreements, money market securities, mortgage and other asset-backed securities, loans and loan participations, and other securities, such as hybrids and synthetic securities, believed to have debt-like characteristics (e.g., securities classified as Tier 2 Regulatory capital, securities that rank above share capital in an insolvency waterfall, securities with maturity dates and non-cancellable interest payment structures). 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. A repurchase agreement is an agreement to buy a security at one price and a simultaneous agreement to sell it back at an agreed-upon price. 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 maintaining a duration of 1 year or less. Managing the fund to have similar overall interest rate risk to the Bloomberg US Treasury Bill: 6-9 Months Index. Normally maintaining a dollar-weighted average maturity of two years or less. Allocating assets across different market sectors and maturities. Investing more than 25% of total assets in the financial services industries. Investing in domestic and foreign issuers. Analyzing the credit quality of the issuer, security-specific features, current and potential future valuation, and trading opportunities to select investments. 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), options, and futures contracts - and forward-settling securities, to adjust the fund's risk exposure.

Performance Narrative [Text Block]

The following information is intended to help you understand the risks of investing in the fund. The information illustrates the performance of the fund's shares over the past year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time. The additional index has 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 Availability Website Address [Text]

www.fidelity.com

Bar Chart [Heading]

Year-by-Year Returns

Bar Chart, Year to Date Return, Date

Sep. 30, 2026

Highest Quarterly Return, Label [Optional Text]

Highest Quarter Return

Highest Quarterly Return

1.24%

Lowest Quarterly Return, Date

Dec. 31, 2025

Performance Table Heading

Average Annual Returns

Performance Table Not Relevant to Tax Deferred

The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).

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. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). 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 .

Prospectus Line Items

Average Annual Return, Percent

2.81%

3.19%

^[4]

Prospectus Line Items

Average Annual Return, Percent

2.83%

3.11%

^[4]

Prospectus Line Items

Average Annual Return, Percent

4.15%

4.59%

Prospectus Line Items

Average Annual Return, Percent

7.30%

5.79%

Prospectus Line Items

Distribution and Service (12b-1) Fees

0.00%

Expenses (as a percentage of Assets)

0.05%

Expense Example, with Redemption, 3 Years

16

Expense Example, with Redemption, 10 Years

$ 64

Average Annual Return, Label [Optional Text]

Return Before Taxes

Annual Return [Percent]

3.72%

1.30%

5.92%

(9.42%)

1.27%

3.10%

Prospectus Line Items

Objective [Heading]

Investment Objective

Expense Heading [Optional Text]

Fee Table

Shareholder Fees Caption [Optional Text]

Shareholder fees

Operating Expenses Caption [Optional Text]

Annual Operating Expenses

Portfolio Turnover [Text Block]

The fund pays transaction costs, such as commissions, when it buys and sells securities (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 15 % of the average value of its portfolio.

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 Narrative [Text Block]

Normally investing at least 80% of assets in municipal securities whose interest is exempt from federal income tax (but may be subject to the federal alternative minimum tax). Normally investing at least 80% of assets in securities included in the Fidelity Systematic U.S. Municipal Bond IndexSM, which aims to increase exposure to municipal bonds with higher risk-adjusted performance and liquidity characteristics relative to traditional market-capitalization weighted U.S. investment grade municipal bond indices. The Fidelity Systematic U.S. Municipal Bond Index SM is constructed using Fidelity's rules-based proprietary index methodology. The universe of securities includes U.S. dollar-denominated investment-grade tax-exempt debt publicly issued in the domestic market by U.S. states and territories, and their political subdivisions, that meet specific criteria such as issue size, deal size and maturity. Mandatory put or mandatory tender securities, as well as original issue zero-coupon bonds, are included in the universe. Floating rate bonds, derivatives, secondarily insured securities, Rule 144A securities, securities in legal default, securities issued under the municipal liquidity facility, or a municipal commercial paper program, and limited offering securities are excluded from the universe. Index constituents are not market capitalization weighted; instead each constituent's weight is determined by its characteristics such as credit quality, issue size, and maturity - aiming for higher risk-adjusted performance at the index level. Additionally, exposure is balanced across maturity buckets to ensure the index's overall duration is similar to traditional indices. Using statistical sampling techniques based on duration, maturity, interest rate sensitivity, security structure, and credit quality to attempt to replicate the returns of the Fidelity Systematic U.S. Municipal Bond IndexSM using a smaller number of securities.

Performance Narrative [Text Block]

Effective April 4, 2025, Fidelity® Municipal Bond Index Fund ("Predecessor Fund") was reorganized into Fidelity® Systematic Municipal Bond Index ETF ("Reorganization"). The Predecessor Fund is designated as the accounting survivor in the Reorganization. Therefore, Fidelity® Systematic Municipal Bond Index ETF has assumed the Predecessor Fund's historical performance and the performance information shown below for periods prior to April 4, 2025, reflects that of the Predecessor Fund. The performance of the Predecessor Fund has not been restated to reflect the annual operating expenses of Fidelity® Systematic Municipal Bond Index ETF, which are lower than those of the Predecessor Fund. Past performance may have been different if Fidelity® Systematic Municipal Bond Index ETF's current fee structure had been in place during the period. 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 Predecessor Fund's shares from year to year and compares the performance of the Predecessor Fund's shares to the performance of the Bloomberg Municipal Bond Index. The Predecessor Fund had a principal investment strategy attempting to replicate the performance of the Bloomberg Municipal Bond Index whereas Fidelity® Systematic Municipal Bond Index ETF has a principal investment strategy to attempt to replicate the performance of the Fidelity Systematic U.S. Municipal Bond Index SM . As a result, the Predecessor Fund's historical performance may not represent Fidelity® Systematic Municipal Bond Index ETF's current principal 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.

Bar Chart [Heading]

Year-by-Year Returns

Bar Chart, Year to Date Return, Date

Sep. 30, 2026

Highest Quarterly Return, Label [Optional Text]

Highest Quarter Return

Highest Quarterly Return

7.70%

Lowest Quarterly Return, Date

Mar. 31, 2022

Performance Table Heading

Average Annual Returns

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.

Average Annual Return, Label [Optional Text]

Return After Taxes on Distributions

Average Annual Return, Label [Optional Text]

Return After Taxes on Distributions and Sale of Fund Shares

Average Annual Return, Label [Optional Text]

Bloomberg Municipal Bond Index

Average Annual Return, Label [Optional Text]

Fidelity Systematic U.S. Municipal Bond Index℠

Management Fees (as a percentage of Assets)

0.20%

Other Expenses (as a percentage of Assets):

0.00%

Expense Example, with Redemption, 1 Year

$ 20

Expense Example, with Redemption, 5 Years

113

Risk/Return [Heading]

Fund Summary Fund: Fidelity® AAA CLO ETF

Objective, Primary [Text Block]

Fidelity® AAA CLO ETF seeks to generate income.

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. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.

Shareholder Fee, Other

$ 0

Portfolio Turnover [Heading]

Portfolio Turnover

Portfolio Turnover, Rate

10.00%

Strategy [Heading]

Principal Investment Strategies

Bar Chart and Performance Table [Heading]

Performance

Performance One Year or Less [Text]

Performance history will be available for the fund after the fund has been in operation for one calendar year.

Prospectus Line Items

Distribution and Service (12b-1) Fees

0.00%

Expenses (as a percentage of Assets)

0.15%

Expense Example, with Redemption, 3 Years

48

Expense Example, with Redemption, 10 Years

$ 192

Average Annual Return, Label [Optional Text]

Return Before Taxes

Annual Return [Percent]

5.46%

5.73%

6.39%

(0.56%)

(0.04%)

1.98%

4.51%

Prospectus Line Items

Objective [Heading]

Investment Objective

Expense Heading [Optional Text]

Fee Table

Shareholder Fees Caption [Optional Text]

Shareholder fees

Operating Expenses Caption [Optional Text]

Annual Operating Expenses

Portfolio Turnover [Text Block]

The fund pays transaction costs, such as commissions, when it buys and sells securities (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 34 % of the average value of its portfolio.

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 Narrative [Text Block]

Normally investing at least 80% of assets in securities included in the Fidelity Low Duration Investment Grade Factor IndexSM. The index is designed to optimize the balance of interest rate risk and credit risk such that both returns and risk measures may be improved relative to traditional U.S. investment grade floating rate note indices. The index is comprised solely of U.S. investment grade floating rate notes and U.S. Treasury notes. The Fidelity Low Duration Investment Grade Factor Index is constructed using Fidelity's rules-based proprietary index methodology. The weight of each component in the blend is set to target a duration, which seeks to optimize the balance of credit risk and interest rate risk. The final weights of securities within the corporate floating rate notes component are determined by their market capitalization, subject to an issuer cap of 3.5%. 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 maintaining a duration of 1 year or less. Using statistical sampling techniques based on duration, maturity, interest rate sensitivity, security structure, and credit quality to attempt to replicate the returns of the Fidelity Low Duration Investment Grade Factor Index℠ using a smaller number of securities. Lending securities to earn income for the fund.

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 and additional indexes over various periods of time. The additional indexes 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 Availability Website Address [Text]

www.fidelity.com

Bar Chart [Heading]

Year-by-Year Returns

Bar Chart, Year to Date Return, Date

Sep. 30, 2026

Highest Quarterly Return, Label [Optional Text]

Highest Quarter Return

Highest Quarterly Return

3.56%

Lowest Quarterly Return, Date

Mar. 31, 2020

Performance Table Heading

Average Annual Returns

Performance Table Not Relevant to Tax Deferred

The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).

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. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). 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.