S000050614 [Member] Average Annual Total Returns |
12 Months Ended | 60 Months Ended | 120 Months Ended | ||
|---|---|---|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2025 |
Dec. 31, 2025 |
|||
| S&P 500 Index | |||||
| Prospectus [Line Items] | |||||
| Average Annual Return, Percent | [1] | 17.88% | 14.43% | 14.82% | |
| Northern Trust Quality Large Cap Index℠ | |||||
| Prospectus [Line Items] | |||||
| Average Annual Return, Percent | [1] | 23.66% | 16.28% | 14.05% | |
| FlexShares US Quality Large Cap Index Fund | |||||
| Prospectus [Line Items] | |||||
| Average Annual Return, Percent | 23.27% | 15.91% | 13.71% | ||
| FlexShares US Quality Large Cap Index Fund | After Taxes on Distributions | |||||
| Prospectus [Line Items] | |||||
| Average Annual Return, Percent | 22.96% | 15.58% | 13.32% | ||
| FlexShares US Quality Large Cap Index Fund | After Taxes on Distributions and Sales | |||||
| Prospectus [Line Items] | |||||
| Average Annual Return, Percent | 13.95% | 12.78% | 11.40% | ||
| |||||