S000073359 [Member] Expense Example - FlexShares ESG & Climate Developed Markets ex-US Core Index Fund - FlexShares ESG & Climate Developed Markets ex-US Core Index Fund	Oct. 31, 2025 USD ($)
Prospectus [Line Items]
Expense Example, with Redemption, 1 Year	$ 12
Expense Example, with Redemption, 3 Years	47
Expense Example, with Redemption, 5 Years	86
Expense Example, with Redemption, 10 Years	$ 201

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