This table describes the fees and expenses that you may pay when you buy, hold, and sell shares of the fund. Investors may also pay commissions or other fees to their financial intermediaries when they buy, hold, and sell shares of the fund, which are not reflected below.

Shareholder Fees - MFS Active Core Plus Bond ETF	MFS Active Core Plus Bond ETF
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price)	0.00%
Maximum Deferred Sales Charge (as a percentage of Offering Price)	0.00%

Annual Fund Operating Expenses [Table]

Annual Fund Operating Expenses - MFS Active Core Plus Bond ETF	MFS Active Core Plus Bond ETF
Management Fees (as a percentage of Assets)	0.34%
Other Expenses (as a percentage of Assets):	0.00%
Expenses (as a percentage of Assets)	0.34%

Expense Example Narrative [Text Block]

This example is intended to help you compare the cost of investing in the fund with the cost of investing in other funds. The example does not take into account brokerage commissions or other fees that you may pay to your financial intermediary when purchasing or selling shares of the fund.

The example assumes that: you invest $10,000 in the fund for the time periods indicated and you redeem your shares at the end of the time periods; your investment has a 5% return each year; and the fund’s operating expenses remain the same.

Expense Example, With Redemption [Table]

Expense Example - MFS Active Core Plus Bond ETF	MFS Active Core Plus Bond ETF USD ($)
Expense Example, with Redemption, 1 Year	$ 35
Expense Example, with Redemption, 3 Years	109
Expense Example, with Redemption, 5 Years	191
Expense Example, with Redemption, 10 Years	$ 431

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 shares are held in a taxable account. These transaction costs, which are not reflected in “Annual Fund Operating Expenses” or in the “Example,” affect the fund’s performance. During the most recent fiscal year, the fund’s portfolio turnover rate was 49% of the average value of its portfolio.

Expense Heading [Optional Text]

Fees and Expenses

Shareholder Fees Caption [Optional Text]

Shareholder Fees (fees paid directly from your investment):

Operating Expenses Caption [Optional Text]

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment):

Expense Example [Heading]

Example

Expense Example by, Year, Caption [Text]

Although your actual costs will likely be higher or lower, under these assumptions your costs would be:

Portfolio Turnover [Heading]

Portfolio Turnover

Portfolio Turnover, Rate

50.00%

Prospectus [Line Items]

Expense Narrative [Text Block]

This table describes the fees and expenses that you may pay when you buy, hold, and sell shares of the fund. Investors may also pay commissions or other fees to their financial intermediaries when they buy, hold, and sell shares of the fund, which are not reflected below.

Shareholder Fees [Table]

Shareholder Fees - MFS Active Intermediate Muni Bond ETF	MFS Active Intermediate Muni Bond ETF
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price)	0.00%
Maximum Deferred Sales Charge (as a percentage of Offering Price)	0.00%

Annual Fund Operating Expenses [Table]

Annual Fund Operating Expenses - MFS Active Intermediate Muni Bond ETF	MFS Active Intermediate Muni Bond ETF
Management Fees (as a percentage of Assets)	0.34%
Other Expenses (as a percentage of Assets):	0.00%
Expenses (as a percentage of Assets)	0.34%

Expense Example Narrative [Text Block]

This example is intended to help you compare the cost of investing in the fund with the cost of investing in other funds. The example does not take into account brokerage commissions or other fees that you may pay to your financial intermediary when purchasing or selling shares of the fund.

The example assumes that: you invest $10,000 in the fund for the time periods indicated and you redeem your shares at the end of the time periods; your investment has a 5% return each year; and the fund’s operating expenses remain the same.

Expense Example, With Redemption [Table]

Expense Example - MFS Active Intermediate Muni Bond ETF	MFS Active Intermediate Muni Bond ETF USD ($)
Expense Example, with Redemption, 1 Year	$ 35
Expense Example, with Redemption, 3 Years	109
Expense Example, with Redemption, 5 Years	191
Expense Example, with Redemption, 10 Years	$ 431

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 shares are held in a taxable account. These transaction costs, which are not reflected in “Annual Fund Operating Expenses” or in the “Example,” affect the fund’s performance. During the most recent fiscal year, the fund’s portfolio turnover rate was 12% of the average value of its portfolio.

Expense Heading [Optional Text]

Fees and Expenses

Shareholder Fees Caption [Optional Text]

Shareholder Fees (fees paid directly from your investment):

Operating Expenses Caption [Optional Text]

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment):

Expense Example [Heading]

Example

Expense Example by, Year, Caption [Text]

Although your actual costs will likely be higher or lower, under these assumptions your costs would be:

Portfolio Turnover [Heading]

Portfolio Turnover

Portfolio Turnover, Rate

10.00%

Prospectus [Line Items]

Expense Narrative [Text Block]

This table describes the fees and expenses that you may pay when you buy, hold, and sell shares of the fund. Investors may also pay commissions or other fees to their financial intermediaries when they buy, hold, and sell shares of the fund, which are not reflected below.

Shareholder Fees [Table]

Shareholder Fees - MFS Active Mid Cap ETF	MFS Active Mid Cap ETF
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price)	0.00%
Maximum Deferred Sales Charge (as a percentage of Offering Price)	0.00%

Annual Fund Operating Expenses [Table]

Annual Fund Operating Expenses - MFS Active Mid Cap ETF	MFS Active Mid Cap ETF
Management Fees (as a percentage of Assets)	0.59%
Other Expenses (as a percentage of Assets):	0.00%	^[1]
Expenses (as a percentage of Assets)	0.59%

[1]	The annual fund operating expenses are based on estimated "Other Expenses" for the current fiscal year expressed as a percentage of the fund’s estimated average net assets during the period.

Expense Example Narrative [Text Block]

This example is intended to help you compare the cost of investing in the fund with the cost of investing in other funds. The example does not take into account brokerage commissions or other fees that you may pay to your financial intermediary when purchasing or selling shares of the fund.

The example assumes that: you invest $10,000 in the fund for the time periods indicated and you redeem your shares at the end of the time periods; your investment has a 5% return each year; and the fund’s operating expenses remain the same.

Expense Example, With Redemption [Table]

Expense Example - MFS Active Mid Cap ETF	MFS Active Mid Cap ETF USD ($)
Expense Example, with Redemption, 1 Year	$ 60
Expense Example, with Redemption, 3 Years	$ 189

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 shares are held in a taxable account. These transaction costs, which are not reflected in “Annual Fund Operating Expenses” or in the “Example,” affect the fund’s performance. For the period from the fund's commencement of operations on September 24, 2025, to the fund's fiscal year end of February 28, 2026, the fund’s portfolio turnover rate was 8% of the average value of its portfolio.

Other Expenses, New Fund, Based on Estimates [Text]

The annual fund operating expenses are based on estimated "Other Expenses" for the current fiscal year expressed as a percentage of the fund’s estimated average net assets during the period.

Prospectus [Line Items]

Expense Narrative [Text Block]

This table describes the fees and expenses that you may pay when you buy, hold, and sell shares of the fund. Investors may also pay commissions or other fees to their financial intermediaries when they buy, hold, and sell shares of the fund, which are not reflected below.

Shareholder Fees [Table]

Shareholder Fees - MFS Active Value ETF	MFS Active Value ETF
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price)	0.00%
Maximum Deferred Sales Charge (as a percentage of Offering Price)	0.00%

Annual Fund Operating Expenses [Table]

Annual Fund Operating Expenses - MFS Active Value ETF	MFS Active Value ETF
Management Fees (as a percentage of Assets)	0.44%
Other Expenses (as a percentage of Assets):	0.00%
Expenses (as a percentage of Assets)	0.44%

Expense Example Narrative [Text Block]

This example is intended to help you compare the cost of investing in the fund with the cost of investing in other funds. The example does not take into account brokerage commissions or other fees that you may pay to your financial intermediary when purchasing or selling shares of the fund.

The example assumes that: you invest $10,000 in the fund for the time periods indicated and you redeem your shares at the end of the time periods; your investment has a 5% return each year; and the fund’s operating expenses remain the same.

Expense Example, With Redemption [Table]

Expense Example - MFS Active Value ETF	MFS Active Value ETF USD ($)
Expense Example, with Redemption, 1 Year	$ 45
Expense Example, with Redemption, 3 Years	141
Expense Example, with Redemption, 5 Years	246
Expense Example, with Redemption, 10 Years	$ 555

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 shares are held in a taxable account. These transaction costs, which are not reflected in “Annual Fund Operating Expenses” or in the “Example,” affect the fund’s performance. During the most recent fiscal year, the fund’s portfolio turnover rate was 10% of the average value of its portfolio.

Expense Heading [Optional Text]

Fees and Expenses

Shareholder Fees Caption [Optional Text]

Shareholder Fees (fees paid directly from your investment):

Operating Expenses Caption [Optional Text]

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment):

Expense Example [Heading]

Example

Expense Example by, Year, Caption [Text]

Although your actual costs will likely be higher or lower, under these assumptions your costs would be:

Portfolio Turnover [Heading]

Portfolio Turnover

Portfolio Turnover, Rate

5.00%

Prospectus [Line Items]

Expense Heading [Optional Text]

Fees and Expenses

Shareholder Fees Caption [Optional Text]

Shareholder Fees (fees paid directly from your investment):

Operating Expenses Caption [Optional Text]

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment):

Expense Example [Heading]

Example

Expense Example by, Year, Caption [Text]

Although your actual costs will likely be higher or lower, under these assumptions your costs would be:

Portfolio Turnover [Heading]

Portfolio Turnover

Other Expenses, New Fund, Based on Estimates [Text]

The annual fund operating expenses are based on estimated "Other Expenses" for the current fiscal year expressed as a percentage of the fund’s estimated average net assets during the period.

Prospectus [Line Items]

Expense Narrative [Text Block]

This table describes the fees and expenses that you may pay when you buy, hold, and sell shares of the fund. Investors may also pay commissions or other fees to their financial intermediaries when they buy, hold, and sell shares of the fund, which are not reflected below.

Shareholder Fees [Table]

Shareholder Fees - MFS Blended Research International Equity ETF	MFS Blended Research International Equity ETF
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price)	0.00%
Maximum Deferred Sales Charge (as a percentage of Offering Price)	0.00%

Annual Fund Operating Expenses [Table]

Annual Fund Operating Expenses - MFS Blended Research International Equity ETF	MFS Blended Research International Equity ETF
Management Fees (as a percentage of Assets)	0.34%
Other Expenses (as a percentage of Assets):	0.00%	^[1]
Expenses (as a percentage of Assets)	0.34%

[1]	The annual fund operating expenses are based on estimated "Other Expenses" for the current fiscal year expressed as a percentage of the fund’s estimated average net assets during the period.

Expense Example Narrative [Text Block]

This example is intended to help you compare the cost of investing in the fund with the cost of investing in other funds. The example does not take into account brokerage commissions or other fees that you may pay to your financial intermediary when purchasing or selling shares of the fund.

The example assumes that: you invest $10,000 in the fund for the time periods indicated and you redeem your shares at the end of the time periods; your investment has a 5% return each year; and the fund’s operating expenses remain the same.

Expense Example, With Redemption [Table]

Expense Example - MFS Blended Research International Equity ETF	MFS Blended Research International Equity ETF USD ($)
Expense Example, with Redemption, 1 Year	$ 35
Expense Example, with Redemption, 3 Years	$ 109

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 shares are held in a taxable account. These transaction costs, which are not reflected in “Annual Fund Operating Expenses” or in the “Example,” affect the fund’s performance. For the period from the fund's commencement of operations on October 22, 2025, to the fund's fiscal year end of February 28, 2026, the fund’s portfolio turnover rate was 8% of the average value of its portfolio.

Other Expenses, New Fund, Based on Estimates [Text]

The annual fund operating expenses are based on estimated "Other Expenses" for the current fiscal year expressed as a percentage of the fund’s estimated average net assets during the period.