v3.25.2
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
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