v3.26.1
Fair Values of Assets and Liabilities - Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - USD ($)
$ in Millions
 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Mar. 31, 2026
Dec. 31, 2025
Mar. 31, 2025
Dec. 31, 2024
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Available-for-sale securities [1] $ 89,085     $ 90,838    
Mortgage loans held for sale 2,645     2,353    
Mortgage servicing rights 3,177 $ 3,305 $ 3,152 3,159 $ 3,312 $ 3,369
Derivative assets netting (3,212)     (3,151)    
Time deposits 13     718    
Long-term debt 1,904     1,414    
Derivative liabilities netting (3,946)     (3,392)    
Equity investments without readily determinable fair values 210     203    
Equity investments without readily determinable fair values impairment loss 0 $ 0        
U.S. Treasury and agencies            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Available-for-sale securities 28,755     28,770    
Residential mortgage-backed securities | Agency            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Available-for-sale securities 39,867     38,010    
Commercial mortgage-backed securities | Agency            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Available-for-sale securities 7,422     7,742    
Commercial mortgage-backed securities | Non-agency            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Available-for-sale securities 7     7    
Asset-backed securities            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Available-for-sale securities 5,535     6,527    
Obligations of state and political subdivisions            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Available-for-sale securities 7,361     9,514    
Other            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Available-for-sale securities 138     268    
Fair Value, Measurements, Recurring            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Available-for-sale securities 89,085     90,838    
Mortgage loans held for sale 2,645     2,353    
Mortgage servicing rights 3,177     3,159    
Derivative assets netting (3,212)     (3,151)    
Derivative assets 3,888     3,701    
Other assets 3,559     2,785    
Total assets 102,354     102,836    
Time deposits 13     718    
Long-term debt 1,904     1,414    
Derivative liabilities netting (3,946)     (3,392)    
Derivative liabilities 3,688     3,400    
Short-term borrowings and other liabilities 2,507     2,513    
Total liabilities 8,112     8,045    
Fair Value, Measurements, Recurring | U.S. Treasury and agencies            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Available-for-sale securities 28,755     28,770    
Fair Value, Measurements, Recurring | Residential mortgage-backed securities            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Available-for-sale securities 39,867     38,010    
Fair Value, Measurements, Recurring | Commercial mortgage-backed securities | Agency            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Available-for-sale securities 7,422     7,742    
Fair Value, Measurements, Recurring | Commercial mortgage-backed securities | Non-agency            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Available-for-sale securities 7     7    
Fair Value, Measurements, Recurring | Asset-backed securities            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Available-for-sale securities 5,535     6,527    
Fair Value, Measurements, Recurring | Obligations of state and political subdivisions            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Available-for-sale securities 7,361     9,514    
Fair Value, Measurements, Recurring | Other            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Available-for-sale securities 138     268    
Fair Value, Measurements, Recurring | Level 1            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Available-for-sale securities 24,099     24,038    
Mortgage loans held for sale 0     0    
Mortgage servicing rights 0     0    
Derivative assets before netting 342     147    
Other assets 695     524    
Total assets 25,136     24,709    
Time deposits 0     0    
Long-term debt 0     0    
Derivative liabilities before netting 114     72    
Short-term borrowings and other liabilities 729     717    
Total liabilities 843     789    
Fair Value, Measurements, Recurring | Level 1 | U.S. Treasury and agencies            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Available-for-sale securities 24,099     24,038    
Fair Value, Measurements, Recurring | Level 1 | Residential mortgage-backed securities            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Available-for-sale securities 0     0    
Fair Value, Measurements, Recurring | Level 1 | Commercial mortgage-backed securities | Agency            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Available-for-sale securities 0     0    
Fair Value, Measurements, Recurring | Level 1 | Commercial mortgage-backed securities | Non-agency            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Available-for-sale securities 0     0    
Fair Value, Measurements, Recurring | Level 1 | Asset-backed securities            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Available-for-sale securities 0     0    
Fair Value, Measurements, Recurring | Level 1 | Obligations of state and political subdivisions            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Available-for-sale securities 0     0    
Fair Value, Measurements, Recurring | Level 1 | Other            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Available-for-sale securities 0     0    
Fair Value, Measurements, Recurring | Level 2            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Available-for-sale securities 64,986     66,800    
Mortgage loans held for sale 2,645     2,353    
Mortgage servicing rights 0     0    
Derivative assets before netting 4,677     4,735    
Other assets 2,864     2,261    
Total assets 75,172     76,149    
Time deposits 13     718    
Long-term debt 1,904     1,414    
Derivative liabilities before netting 5,188     4,538    
Short-term borrowings and other liabilities 1,778     1,796    
Total liabilities 8,883     8,466    
Fair Value, Measurements, Recurring | Level 2 | U.S. Treasury and agencies            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Available-for-sale securities 4,656     4,732    
Fair Value, Measurements, Recurring | Level 2 | Residential mortgage-backed securities            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Available-for-sale securities 39,867     38,010    
Fair Value, Measurements, Recurring | Level 2 | Commercial mortgage-backed securities | Agency            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Available-for-sale securities 7,422     7,742    
Fair Value, Measurements, Recurring | Level 2 | Commercial mortgage-backed securities | Non-agency            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Available-for-sale securities 7     7    
Fair Value, Measurements, Recurring | Level 2 | Asset-backed securities            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Available-for-sale securities 5,535     6,527    
Fair Value, Measurements, Recurring | Level 2 | Obligations of state and political subdivisions            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Available-for-sale securities 7,361     9,514    
Fair Value, Measurements, Recurring | Level 2 | Other            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Available-for-sale securities 138     268    
Fair Value, Measurements, Recurring | Level 3            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Available-for-sale securities 0     0    
Mortgage loans held for sale 0     0    
Mortgage servicing rights 3,177     3,159    
Derivative assets before netting 2,081     1,970    
Other assets 0     0    
Total assets 5,258     5,129    
Time deposits 0     0    
Long-term debt 0     0    
Derivative liabilities before netting 2,332     2,182    
Short-term borrowings and other liabilities 0     0    
Total liabilities 2,332     2,182    
Fair Value, Measurements, Recurring | Level 3 | U.S. Treasury and agencies            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Available-for-sale securities 0     0    
Fair Value, Measurements, Recurring | Level 3 | Residential mortgage-backed securities            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Available-for-sale securities 0     0    
Fair Value, Measurements, Recurring | Level 3 | Commercial mortgage-backed securities | Agency            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Available-for-sale securities 0     0    
Fair Value, Measurements, Recurring | Level 3 | Commercial mortgage-backed securities | Non-agency            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Available-for-sale securities 0     0    
Fair Value, Measurements, Recurring | Level 3 | Asset-backed securities            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Available-for-sale securities 0     0    
Fair Value, Measurements, Recurring | Level 3 | Obligations of state and political subdivisions            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Available-for-sale securities 0     0    
Fair Value, Measurements, Recurring | Level 3 | Other            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Available-for-sale securities $ 0     $ 0    
[1] Includes only collateral pledged by the Company where counterparties have the right to sell or pledge the collateral.