v3.26.1
S000012098 [Member] Expense Example, No Redemption - Columbia U.S. Treasury Index Fund
Apr. 30, 2026
USD ($)
Columbia U.S. Treasury Index Fund Class A  
Prospectus [Line Items]  
Expense Example, No Redemption, 1 Year $ 33
Expense Example, No Redemption, 3 Years 153
Expense Example, No Redemption, 5 Years 284
Expense Example, No Redemption, 10 Years 667
Columbia U.S. Treasury Index Fund Institutional Class  
Prospectus [Line Items]  
Expense Example, No Redemption, 1 Year 17
Expense Example, No Redemption, 3 Years 105
Expense Example, No Redemption, 5 Years 201
Expense Example, No Redemption, 10 Years 483
Columbia U.S. Treasury Index Fund Institutional 2 Class  
Prospectus [Line Items]  
Expense Example, No Redemption, 1 Year 17
Expense Example, No Redemption, 3 Years 105
Expense Example, No Redemption, 5 Years 201
Expense Example, No Redemption, 10 Years 483
Columbia U.S. Treasury Index Fund Institutional 3 Class  
Prospectus [Line Items]  
Expense Example, No Redemption, 1 Year 17
Expense Example, No Redemption, 3 Years 105
Expense Example, No Redemption, 5 Years 201
Expense Example, No Redemption, 10 Years $ 483