Shareholder Report, Holdings (Details)	Apr. 30, 2025
Columbia U.S. Treasury Index Fund - Class A \| U.S. Treasury 02/15/2035 4.625% [Member]
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Columbia U.S. Treasury Index Fund - Class A \| U.S. Treasury 05/15/2034 4.375% [Member]
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Columbia U.S. Treasury Index Fund - Class A \| U.S. Treasury 02/15/2034 4.000% [Member]
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Columbia U.S. Treasury Index Fund - Class A \| U.S. Treasury 11/15/2034 4.250% [Member]
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Columbia U.S. Treasury Index Fund - Class A \| U.S. Treasury 11/15/2033 4.500% [Member]
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Columbia U.S. Treasury Index Fund - Class A \| U.S. Treasury 08/15/2034 3.875% [Member]
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Columbia U.S. Treasury Index Fund - Class A \| U.S. Treasury 08/15/2033 3.875% [Member]
Holdings [Line Items]
Percent of Net Asset Value	0.80%
Columbia U.S. Treasury Index Fund - Class A \| U.S. Treasury 02/28/2030 4.000% [Member]
Holdings [Line Items]
Percent of Net Asset Value	0.80%
Columbia U.S. Treasury Index Fund - Class A \| U.S. Treasury 11/15/2032 4.125% [Member]
Holdings [Line Items]
Percent of Net Asset Value	0.80%
Columbia U.S. Treasury Index Fund - Class A \| U.S. Treasury 02/15/2033 3.500% [Member]
Holdings [Line Items]
Percent of Net Asset Value	0.70%
Columbia U.S. Treasury Index Fund - Class A \| AA rating [Member]
Holdings [Line Items]
Percent of Net Asset Value	98.90%
Columbia U.S. Treasury Index Fund - Class A \| U.S. Treasury Obligations [Member]
Holdings [Line Items]
Percent of Net Asset Value	98.90%
Columbia U.S. Treasury Index Fund - Class A \| Other [Member]
Holdings [Line Items]
Percent of Net Asset Value	0.30%
Columbia U.S. Treasury Index Fund - Institutional Class \| U.S. Treasury 02/15/2035 4.625% [Member]
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Columbia U.S. Treasury Index Fund - Institutional Class \| U.S. Treasury 05/15/2034 4.375% [Member]
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Columbia U.S. Treasury Index Fund - Institutional Class \| U.S. Treasury 02/15/2034 4.000% [Member]
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Columbia U.S. Treasury Index Fund - Institutional Class \| U.S. Treasury 11/15/2034 4.250% [Member]
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Columbia U.S. Treasury Index Fund - Institutional Class \| U.S. Treasury 11/15/2033 4.500% [Member]
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Columbia U.S. Treasury Index Fund - Institutional Class \| U.S. Treasury 08/15/2034 3.875% [Member]
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Columbia U.S. Treasury Index Fund - Institutional Class \| U.S. Treasury 08/15/2033 3.875% [Member]
Holdings [Line Items]
Percent of Net Asset Value	0.80%
Columbia U.S. Treasury Index Fund - Institutional Class \| U.S. Treasury 02/28/2030 4.000% [Member]
Holdings [Line Items]
Percent of Net Asset Value	0.80%
Columbia U.S. Treasury Index Fund - Institutional Class \| U.S. Treasury 11/15/2032 4.125% [Member]
Holdings [Line Items]
Percent of Net Asset Value	0.80%
Columbia U.S. Treasury Index Fund - Institutional Class \| U.S. Treasury 02/15/2033 3.500% [Member]
Holdings [Line Items]
Percent of Net Asset Value	0.70%
Columbia U.S. Treasury Index Fund - Institutional Class \| AA rating [Member]
Holdings [Line Items]
Percent of Net Asset Value	98.90%
Columbia U.S. Treasury Index Fund - Institutional Class \| U.S. Treasury Obligations [Member]
Holdings [Line Items]
Percent of Net Asset Value	98.90%
Columbia U.S. Treasury Index Fund - Institutional Class \| Other [Member]
Holdings [Line Items]
Percent of Net Asset Value	0.30%
Columbia U.S. Treasury Index Fund - Institutional 2 Class \| U.S. Treasury 02/15/2035 4.625% [Member]
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Columbia U.S. Treasury Index Fund - Institutional 2 Class \| U.S. Treasury 05/15/2034 4.375% [Member]
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Columbia U.S. Treasury Index Fund - Institutional 2 Class \| U.S. Treasury 02/15/2034 4.000% [Member]
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Columbia U.S. Treasury Index Fund - Institutional 2 Class \| U.S. Treasury 11/15/2034 4.250% [Member]
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Columbia U.S. Treasury Index Fund - Institutional 2 Class \| U.S. Treasury 11/15/2033 4.500% [Member]
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Columbia U.S. Treasury Index Fund - Institutional 2 Class \| U.S. Treasury 08/15/2034 3.875% [Member]
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Columbia U.S. Treasury Index Fund - Institutional 2 Class \| U.S. Treasury 08/15/2033 3.875% [Member]
Holdings [Line Items]
Percent of Net Asset Value	0.80%
Columbia U.S. Treasury Index Fund - Institutional 2 Class \| U.S. Treasury 02/28/2030 4.000% [Member]
Holdings [Line Items]
Percent of Net Asset Value	0.80%
Columbia U.S. Treasury Index Fund - Institutional 2 Class \| U.S. Treasury 11/15/2032 4.125% [Member]
Holdings [Line Items]
Percent of Net Asset Value	0.80%
Columbia U.S. Treasury Index Fund - Institutional 2 Class \| U.S. Treasury 02/15/2033 3.500% [Member]
Holdings [Line Items]
Percent of Net Asset Value	0.70%
Columbia U.S. Treasury Index Fund - Institutional 2 Class \| AA rating [Member]
Holdings [Line Items]
Percent of Net Asset Value	98.90%
Columbia U.S. Treasury Index Fund - Institutional 2 Class \| U.S. Treasury Obligations [Member]
Holdings [Line Items]
Percent of Net Asset Value	98.90%
Columbia U.S. Treasury Index Fund - Institutional 2 Class \| Other [Member]
Holdings [Line Items]
Percent of Net Asset Value	0.30%
Columbia U.S. Treasury Index Fund - Institutional 3 Class \| U.S. Treasury 02/15/2035 4.625% [Member]
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Columbia U.S. Treasury Index Fund - Institutional 3 Class \| U.S. Treasury 05/15/2034 4.375% [Member]
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Columbia U.S. Treasury Index Fund - Institutional 3 Class \| U.S. Treasury 02/15/2034 4.000% [Member]
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Columbia U.S. Treasury Index Fund - Institutional 3 Class \| U.S. Treasury 11/15/2034 4.250% [Member]
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Columbia U.S. Treasury Index Fund - Institutional 3 Class \| U.S. Treasury 11/15/2033 4.500% [Member]
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Columbia U.S. Treasury Index Fund - Institutional 3 Class \| U.S. Treasury 08/15/2034 3.875% [Member]
Holdings [Line Items]
Percent of Net Asset Value	0.90%
Columbia U.S. Treasury Index Fund - Institutional 3 Class \| U.S. Treasury 08/15/2033 3.875% [Member]
Holdings [Line Items]
Percent of Net Asset Value	0.80%
Columbia U.S. Treasury Index Fund - Institutional 3 Class \| U.S. Treasury 02/28/2030 4.000% [Member]
Holdings [Line Items]
Percent of Net Asset Value	0.80%
Columbia U.S. Treasury Index Fund - Institutional 3 Class \| U.S. Treasury 11/15/2032 4.125% [Member]
Holdings [Line Items]
Percent of Net Asset Value	0.80%
Columbia U.S. Treasury Index Fund - Institutional 3 Class \| U.S. Treasury 02/15/2033 3.500% [Member]
Holdings [Line Items]
Percent of Net Asset Value	0.70%
Columbia U.S. Treasury Index Fund - Institutional 3 Class \| AA rating [Member]
Holdings [Line Items]
Percent of Net Asset Value	98.90%
Columbia U.S. Treasury Index Fund - Institutional 3 Class \| U.S. Treasury Obligations [Member]
Holdings [Line Items]
Percent of Net Asset Value	98.90%
Columbia U.S. Treasury Index Fund - Institutional 3 Class \| Other [Member]
Holdings [Line Items]
Percent of Net Asset Value	0.30%

Shareholder Report, Holdings (Details)

Apr. 30, 2025