Shareholder Report, Line Graph (Details) - USD ($) |
12 Months Ended | 24 Months Ended | 36 Months Ended | 48 Months Ended | 60 Months Ended | 72 Months Ended | 84 Months Ended | 96 Months Ended | 108 Months Ended | 120 Months Ended | 132 Months Ended | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Apr. 30, 2025 |
Apr. 30, 2015 |
Apr. 30, 2016 |
Apr. 30, 2017 |
Apr. 30, 2018 |
Apr. 30, 2019 |
Apr. 30, 2020 |
Apr. 30, 2021 |
Apr. 30, 2022 |
Apr. 30, 2023 |
Apr. 30, 2024 |
Apr. 30, 2025 |
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| Columbia U.S. Treasury Index Fund - Class A | ||||||||||||
| Account Value [Line Items] | ||||||||||||
| Line Graph and Table Measure Name | Class A | |||||||||||
| Accumulated Value | $ 10,000 | $ 10,238 | $ 10,142 | $ 10,006 | $ 10,438 | $ 11,887 | $ 11,332 | $ 10,478 | $ 10,346 | $ 10,035 | $ 10,763 | |
| Columbia U.S. Treasury Index Fund - Institutional Class | ||||||||||||
| Account Value [Line Items] | ||||||||||||
| Line Graph and Table Measure Name | Institutional Class | |||||||||||
| Accumulated Value | 10,000 | 10,254 | 10,172 | 10,051 | 10,510 | 11,976 | 11,444 | 10,588 | 10,481 | 10,171 | 10,937 | |
| Columbia U.S. Treasury Index Fund - Institutional 2 Class | ||||||||||||
| Account Value [Line Items] | ||||||||||||
| Line Graph and Table Measure Name | Institutional 2 Class | |||||||||||
| Accumulated Value | 10,000 | 10,254 | 10,172 | 10,050 | 10,500 | 11,968 | 11,435 | 10,587 | 10,479 | 10,168 | 10,934 | |
| Columbia U.S. Treasury Index Fund - Institutional 3 Class | ||||||||||||
| Account Value [Line Items] | ||||||||||||
| Line Graph and Table Measure Name | Institutional 3 Class | |||||||||||
| Accumulated Value | 10,000 | 10,254 | 10,171 | 10,042 | 10,500 | 11,967 | 11,430 | 10,580 | 10,474 | 10,168 | 10,920 | |
| Bloomberg U.S. Aggregate Bond Index [Member] | ||||||||||||
| Account Value [Line Items] | ||||||||||||
| Line Graph and Table Measure Name | Bloomberg U.S. Aggregate Bond Index | |||||||||||
| Accumulated Value | 10,000 | 10,272 | 10,357 | 10,324 | 10,870 | 12,049 | 12,017 | 10,994 | 10,947 | 10,786 | 11,651 | |
| FTSE USBIG Treasury Index [Member] | ||||||||||||
| Account Value [Line Items] | ||||||||||||
| Line Graph and Table Measure Name | FTSE USBIG Treasury Index | |||||||||||
| Accumulated Value | $ 10,000 | $ 10,277 | $ 10,213 | $ 10,106 | $ 10,584 | $ 12,087 | $ 11,563 | $ 10,736 | $ 10,625 | $ 10,332 | $ 11,124 | |