v3.26.1
Contingent Liabilities and Guarantees - Narrative (Details) - USD ($)
$ in Millions
3 Months Ended
Mar. 31, 2026
Dec. 31, 2025
Mar. 31, 2025
Dec. 31, 2024
Commitments Contingencies And Guarantees [Line Items]        
Reserve for potential losses $ 296 $ 313 $ 278 $ 290
Standby letters of credit        
Commitments Contingencies And Guarantees [Line Items]        
Remaining weighted-average life of standby letters of credit (in years) 2 years 1 month 6 days      
Recourse agreement with FNMA        
Commitments Contingencies And Guarantees [Line Items]        
Weighted-average remaining term for outstanding commercial mortgage loans (in years) 5 years 8 months 12 days      
Unpaid principal balance outstanding of loans sold $ 25,200      
Maximum potential amount of undiscounted future payments possibly required as percentage of principal balance of loans outstanding (as a percent) 32.70%      
Reserve for potential losses $ 59      
Residential mortgage reserve        
Commitments Contingencies And Guarantees [Line Items]        
Unpaid principal balance outstanding of loans sold $ 11,500      
Maximum potential amount of undiscounted future payments possibly required as percentage of principal balance of loans outstanding (as a percent) 30.00%      
Liability for estimated repurchase obligations on loans sold $ 8      
Written options        
Commitments Contingencies And Guarantees [Line Items]        
Weighted average life of written put options (in years) 1 year 4 months 24 days      
Minimum | Standby letters of credit        
Commitments Contingencies And Guarantees [Line Items]        
Remaining actual life of standby letters of credit (in years) 1 year      
Minimum | Low        
Commitments Contingencies And Guarantees [Line Items]        
Guarantee obligations (as a percent) 0.00%      
Minimum | Moderate        
Commitments Contingencies And Guarantees [Line Items]        
Guarantee obligations (as a percent) 30.00%      
Minimum | High        
Commitments Contingencies And Guarantees [Line Items]        
Guarantee obligations (as a percent) 70.00%      
Maximum | Standby letters of credit        
Commitments Contingencies And Guarantees [Line Items]        
Remaining actual life of standby letters of credit (in years) 8 years 8 months 12 days      
Maximum | Low        
Commitments Contingencies And Guarantees [Line Items]        
Guarantee obligations (as a percent) 30.00%      
Maximum | Moderate        
Commitments Contingencies And Guarantees [Line Items]        
Guarantee obligations (as a percent) 70.00%