v3.26.1
Annual Total Returns - American Century Government Income Trust
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
CAPITAL PRESERVATION FUND | CAPITAL PRESERVATION FUND INVESTOR CLASS                    
Prospectus [Line Items]                    
Annual Return [Percent] 3.87% 4.82% 4.64% 1.19% 0.01% 0.25% 1.75% 1.38% 0.41% 0.01%
GINNIE MAE FUND | GINNIE MAE FUND INVESTOR CLASS                    
Prospectus [Line Items]                    
Annual Return [Percent] 7.41% 0.51% 4.71% (11.51%) (1.65%) 3.71% 6.16% 0.42% 1.21% 1.05%
GOVERNMENT BOND FUND | GOVERNMENT BOND FUND INVESTOR CLASS                    
Prospectus [Line Items]                    
Annual Return [Percent] 7.24% 0.31% 3.50% (12.55%) (1.14%) 6.69% 6.16% 0.56% 2.14% 0.85%
SHORT-TERM GOVERNMENT FUND | SHORT-TERM GOVERNMENT FUND INVESTOR CLASS                    
Prospectus [Line Items]                    
Annual Return [Percent] 4.91% 3.56% 3.68% (3.96%) (0.09%) 3.35% 2.91% 1.11% 0.21% 0.41%
INFLATION-ADJUSTED BOND FUND | INFLATION-ADJUSTED BOND FUND INVESTOR CLASS                    
Prospectus [Line Items]                    
Annual Return [Percent] 6.67% 1.68% 3.16% (12.38%) 6.37% 10.28% 7.85% (2.51%) 3.08% 4.72%