v3.26.1
Goodwill and Mortgage Servicing Rights (Mortgage Servicing Rights) (Details) - USD ($)
$ in Millions
6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Servicing Asset at Fair Value, Amount [Roll Forward]    
Mortgage servicing rights, beginning balance $ 3,659  
Mortgage servicing rights, ending balance 3,801  
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 1,039 1,010
Unpaid principal balance of loans serviced for others at end of period 294,011 294,675
Servicing advances 690 707
Mortgage Servicing Rights | Commercial real estate | Time and Payoffs    
Servicing Asset at Fair Value, Amount [Roll Forward]    
Changes in Fair Value (146) (155)
Mortgage Servicing Rights | Commercial real estate | Other    
Servicing Asset at Fair Value, Amount [Roll Forward]    
Changes in Fair Value 107 11
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 26 24
Mortgage Servicing Rights | Commercial real estate | Purchases    
Servicing Asset at Fair Value, Amount [Roll Forward]    
Additions 31 45
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 2,762 2,457
Unpaid principal balance of loans serviced for others at end of period 208,949 189,216
Servicing advances 103 110
Mortgage Servicing Rights | Residential mortgage loans held for sale | Time and Payoffs    
Servicing Asset at Fair Value, Amount [Roll Forward]    
Changes in Fair Value (155) (127)
Mortgage Servicing Rights | Residential mortgage loans held for sale | Other    
Servicing Asset at Fair Value, Amount [Roll Forward]    
Changes in Fair Value 9 (57)
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 20 14
Mortgage Servicing Rights | Residential mortgage loans held for sale | Purchases    
Servicing Asset at Fair Value, Amount [Roll Forward]    
Additions $ 240 $ 1