v3.26.1
Goodwill and Mortgage Servicing Rights (Mortgage Servicing Rights) (Details) - USD ($)
$ in Millions
3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Servicing Asset at Fair Value, Amount [Roll Forward]    
Mortgage servicing rights, beginning balance $ 3,659  
Mortgage servicing rights, ending balance 3,816  
Mortgage Servicing Rights | Commercial real estate    
Servicing Asset at Fair Value, Amount [Roll Forward]    
Mortgage servicing rights, beginning balance 1,021 $ 1,085
Mortgage servicing rights, ending balance 1,030 1,041
Unpaid principal balance of loans serviced for others at end of period 296,482 293,685
Servicing advances 642 641
Mortgage Servicing Rights | Commercial real estate | Time and Payoffs    
Servicing Asset at Fair Value, Amount [Roll Forward]    
Changes in Fair Value (71) (78)
Mortgage Servicing Rights | Commercial real estate | Other    
Servicing Asset at Fair Value, Amount [Roll Forward]    
Changes in Fair Value 49 (2)
Mortgage Servicing Rights | Commercial real estate | FirstBank Acquisition    
Servicing Asset at Fair Value, Amount [Roll Forward]    
Additions 0 0
Mortgage Servicing Rights | Commercial real estate | From loans sold with servicing retained    
Servicing Asset at Fair Value, Amount [Roll Forward]    
Additions 15 9
Mortgage Servicing Rights | Commercial real estate | Purchases    
Servicing Asset at Fair Value, Amount [Roll Forward]    
Additions 16 27
Mortgage Servicing Rights | Residential mortgage loans held for sale    
Servicing Asset at Fair Value, Amount [Roll Forward]    
Mortgage servicing rights, beginning balance 2,638 2,626
Mortgage servicing rights, ending balance 2,786 2,523
Unpaid principal balance of loans serviced for others at end of period 212,261 193,417
Servicing advances 121 133
Mortgage Servicing Rights | Residential mortgage loans held for sale | Time and Payoffs    
Servicing Asset at Fair Value, Amount [Roll Forward]    
Changes in Fair Value (73) (60)
Mortgage Servicing Rights | Residential mortgage loans held for sale | Other    
Servicing Asset at Fair Value, Amount [Roll Forward]    
Changes in Fair Value (13) (51)
Mortgage Servicing Rights | Residential mortgage loans held for sale | FirstBank Acquisition    
Servicing Asset at Fair Value, Amount [Roll Forward]    
Additions 10 0
Mortgage Servicing Rights | Residential mortgage loans held for sale | From loans sold with servicing retained    
Servicing Asset at Fair Value, Amount [Roll Forward]    
Additions 10 7
Mortgage Servicing Rights | Residential mortgage loans held for sale | Purchases    
Servicing Asset at Fair Value, Amount [Roll Forward]    
Additions $ 214 $ 1