v3.26.1
Regulatory Requirements - Regulatory Capital and Ratios (Details)
$ in Millions
Jun. 30, 2026
USD ($)
Dec. 31, 2025
USD ($)
CSC    
Common Equity Tier 1 Risk-Based Capital    
Actual Amount $ 36,538 $ 36,081
Actual Ratio 0.244 0.304
Minimum Capital Requirement Amount $ 6,751 $ 5,345
Minimum Capital Requirement Ratio 0.045 0.045
Tier 1 Risk-Based Capital    
Actual Amount $ 42,751 $ 42,844
Actual Ratio 0.285 0.361
Minimum Capital Requirement Amount $ 9,002 $ 7,127
Minimum Capital Requirement Ratio 0.060 0.060
Total Risk-Based Capital    
Actual Amount $ 42,792 $ 42,894
Actual Ratio 0.285 0.361
Minimum Capital Requirement Amount $ 12,002 $ 9,503
Minimum Capital Requirement Ratio 0.080 0.080
Tier 1 Leverage    
Actual Amount $ 42,751 $ 42,844
Actual Ratio 0.087 0.093
Minimum Capital Requirement Amount $ 19,589 $ 18,499
Minimum Capital Requirement Ratio 0.040 0.040
Supplementary Leverage Ratio    
Actual Amount $ 42,751 $ 42,844
Actual Ratio 0.086 0.092
Minimum Capital Requirement Amount $ 14,852 $ 13,974
Minimum Capital Requirement Ratio 0.030 0.030
CSB    
Common Equity Tier 1 Risk-Based Capital    
Actual Amount $ 27,085 $ 28,126
Actual Ratio 0.301 0.359
Minimum to be Well Capitalized Amount $ 5,840 $ 5,088
Minimum to be Well Capitalized Ratio 0.065 0.065
Minimum Capital Requirement Amount $ 4,043 $ 3,523
Minimum Capital Requirement Ratio 0.045 0.045
Tier 1 Risk-Based Capital    
Actual Amount $ 27,085 $ 28,126
Actual Ratio 0.301 0.359
Minimum to be Well Capitalized Amount $ 7,188 $ 6,262
Minimum to be Well Capitalized Ratio 0.080 0.080
Minimum Capital Requirement Amount $ 5,391 $ 4,697
Minimum Capital Requirement Ratio 0.060 0.060
Total Risk-Based Capital    
Actual Amount $ 27,124 $ 28,163
Actual Ratio 0.302 0.360
Minimum to be Well Capitalized Amount $ 8,985 $ 7,828
Minimum to be Well Capitalized Ratio 0.100 0.100
Minimum Capital Requirement Amount $ 7,188 $ 6,262
Minimum Capital Requirement Ratio 0.080 0.080
Tier 1 Leverage    
Actual Amount $ 27,085 $ 28,126
Actual Ratio 0.107 0.111
Minimum to be Well Capitalized Amount $ 12,711 $ 12,641
Minimum to be Well Capitalized Ratio 0.050 0.050
Minimum Capital Requirement Amount $ 10,169 $ 10,113
Minimum Capital Requirement Ratio 0.040 0.040
Supplementary Leverage Ratio    
Actual Amount $ 27,085 $ 28,126
Actual Ratio 0.105 0.110
Minimum Capital Requirement Amount $ 7,710 $ 7,649
Minimum Capital Requirement Ratio 0.030 0.030