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S000065839 [Member] Performance Management - FlexShares Emerging Markets Quality Low Volatility Index Fund
Oct. 31, 2025
Prospectus [Line Items]  
Bar Chart and Performance Table [Heading] Fund Performance
Performance Narrative [Text Block]
The bar chart and table that follow show how the Fund has performed on a calendar year basis and provide an indication of the risks of investing in the Fund by showing (A) changes in the Fund’s performance from year to year, (B) how the Fund’s average annual returns compare with those of a broad-based securities market index and one or more style-specific indexes (reflecting the market segments in which the Fund invests), in that order. Past performance (before and after taxes) does not necessarily indicate how the Fund will perform in the future. Updated information on the Fund’s performance results can be obtained by visiting flexshares.com.
Performance Past Does Not Indicate Future [Text] Past performance (before and after taxes) does not necessarily indicate how the Fund will perform in the future.
Performance Information Illustrates Variability of Returns [Text] The bar chart and table that follow show how the Fund has performed on a calendar year basis and provide an indication of the risks of investing in the Fund by showing (A) changes in the Fund’s performance from year to year, (B) how the Fund’s average annual returns compare with those of a broad-based securities market index and one or more style-specific indexes (reflectingthe market segments in which the Fund invests),in that order.
Bar Chart [Heading] Calendar Year Total Returns
Bar Chart Closing [Text Block]
For the period shown in the bar chart above:
Best Quarter (6/30/2020): 12.19%
Worst Quarter (3/31/2020): -21.67%
Performance Table Heading Average Annual Total Returns (for the periods ended December 31, 2025) 
Performance Table Narrative
After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement plans. After-tax returns may exceed the return before taxes due to an assumed tax benefit from realizing a capital loss on a sale of Fund shares.
Performance Table Uses Highest Federal Rate After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes.
Performance Table Not Relevant to Tax Deferred After-tax returns shown are not relevant to investors who hold shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement plans.
Performance Table Explanation after Tax Higher After-tax returns may exceed the return before taxes due to an assumed tax benefit from realizing a capital loss on a sale of Fund shares.
Index No Deduction for Fees, Expenses, or Taxes [Text] Reflects no deduction for fees, expenses or taxes.
Performance Availability Website Address [Text] flexshares.com
FlexShares Emerging Markets Quality Low Volatility Index Fund  
Prospectus [Line Items]  
Highest Quarterly Return, Label [Optional Text] Best Quarter
Highest Quarterly Return 12.19%
Highest Quarterly Return, Date Jun. 30, 2020
Lowest Quarterly Return, Label [Optional Text] Worst Quarter
Lowest Quarterly Return (21.67%)
Lowest Quarterly Return, Date Mar. 31, 2020