S000033314 [Member] Average Annual Total Returns

12 Months Ended

60 Months Ended

120 Months Ended

Dec. 31, 2025

Dec. 31, 2025

Dec. 31, 2025

MSCI Emerging Markets Index

Prospectus [Line Items]

Average Annual Return, Percent

^[1]

33.57%

4.20%

8.42%

MSCI Emerging Markets Investable Market Index [Member]

Prospectus [Line Items]

Average Annual Return, Percent

^[1]

31.38%

4.67%

8.37%

Morningstar® Emerging Markets Factor Tilt Index℠

Prospectus [Line Items]

Average Annual Return, Percent

^[1]

29.82%

6.88%

8.62%

FlexShares Morningstar Emerging Markets Factor Tilt Index Fund

Prospectus [Line Items]

Average Annual Return, Percent

29.57%

5.96%

7.77%

FlexShares Morningstar Emerging Markets Factor Tilt Index Fund | After Taxes on Distributions

Prospectus [Line Items]

Average Annual Return, Percent

28.37%

5.03%

6.99%

FlexShares Morningstar Emerging Markets Factor Tilt Index Fund | After Taxes on Distributions and Sales

Prospectus [Line Items]

Average Annual Return, Percent

18.24%

4.50%

6.17%

[1]	Reflects no deduction for fees, expenses or taxes.