v3.26.1
Loans and allowance for loan losses - Changes in Allowance for Credit Losses (Detail) - USD ($)
$ in Millions
 3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Accounts Receivable, Allowance for Credit Loss [Roll Forward]    
Beginning balance $ 2,116 $ 2,184
Provision for credit losses 125 130
Charge-offs (153) (160)
Recoveries 48 46
Net charge-offs (105) (114)
Ending balance 2,136 2,200
Commercial and industrial    
Accounts Receivable, Allowance for Credit Loss [Roll Forward]    
Beginning balance 771 769
Provision for credit losses 71 22
Charge-offs (46) (50)
Recoveries 21 21
Net charge-offs (25) (29)
Ending balance 817 762
Commercial Real Estate    
Accounts Receivable, Allowance for Credit Loss [Roll Forward]    
Beginning balance 472 599
Provision for credit losses (34) 30
Charge-offs (18) (22)
Recoveries 1 3
Net charge-offs (17) (19)
Ending balance 421 610
Residential Real Estate    
Accounts Receivable, Allowance for Credit Loss [Roll Forward]    
Beginning balance 100 108
Provision for credit losses (2) (3)
Charge-offs (1) (2)
Recoveries 2 2
Net charge-offs 1 0
Ending balance 99 105
Consumer    
Accounts Receivable, Allowance for Credit Loss [Roll Forward]    
Beginning balance 773 708
Provision for credit losses 90 81
Charge-offs (88) (86)
Recoveries 24 20
Net charge-offs (64) (66)
Ending balance 799 723
Reserve for Unfunded Credit Commitments    
Accounts Receivable, Allowance for Credit Loss [Roll Forward]    
Beginning balance 80 60
Provision for credit losses 15 0
Charge-offs 0 0
Recoveries 0 0
Net charge-offs 0 0
Ending balance $ 95 $ 60