v3.26.1
Regulation and Capital Adequacy - Risk Based Capital Requirements (Detail)
$ in Millions
Mar. 31, 2026
USD ($)
Dec. 31, 2025
USD ($)
Standardized    
Risk Based Capital Requirements [Abstract]    
CET1 capital ratio 0.045 0.045
Tier 1 capital ratio 0.060 0.060
Total capital ratio 0.080 0.080
Advanced    
Risk Based Capital Requirements [Abstract]    
CET1 capital ratio 0.045 0.045
Tier 1 capital ratio 0.060 0.060
Total capital ratio 0.080 0.080
Reportable Legal Entities    
Risk Based Capital Requirements [Abstract]    
CET1 capital ratio 0.045 0.045
Tier 1 capital ratio 0.060 0.060
Total capital ratio 0.105 0.105
Reportable Legal Entities | Standardized    
Risk-Based Capital and Risk-Weighted Assets [Abstract]    
CET1 capital $ 62,646 $ 64,071
Tier 1 capital 62,646 64,071
Tier 2 capital 2,201 2,052
Total capital 64,847 66,123
RWAs $ 445,853 $ 409,796
Risk-Based Capital Ratios [Abstract]    
CET1 capital ratio 0.141 0.156
Tier 1 capital ratio 0.141 0.156
Total capital ratio 0.145 0.161
Reportable Legal Entities | Advanced    
Risk-Based Capital and Risk-Weighted Assets [Abstract]    
CET1 capital $ 62,646 $ 64,071
Tier 1 capital 62,646 64,071
Tier 2 capital 617 677
Total capital 63,263 64,748
RWAs $ 345,372 $ 306,699
Risk-Based Capital Ratios [Abstract]    
CET1 capital ratio 0.181 0.209
Tier 1 capital ratio 0.181 0.209
Total capital ratio 0.183 0.211