v3.26.1
Loans and allowance for loan losses - Summary of Loan grades applied various classes of Commercial and Real Estate Loans (Detail) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Dec. 31, 2025
Financing Receivable, Credit Quality Indicator [Line Items]          
Year one $ 15,481   $ 15,481   $ 23,922
Year two 21,126   21,126   14,450
Year three 12,538   12,538   11,389
Year four 9,860   9,860   14,171
Year five 12,420   12,420   9,181
Prior 33,998   33,998   28,808
Total [1] 143,193   143,193   138,702
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]          
Year one     5    
Year two     35    
Year three     50    
Year four     41    
Year five     26    
Prior     64    
Total 138 $ 156 291 $ 316  
Commercial and industrial          
Financing Receivable, Credit Quality Indicator [Line Items]          
Year one 6,839   6,839   9,686
Year two 8,672   8,672   7,026
Year three 5,978   5,978   4,626
Year four 3,784   3,784   4,541
Year five 3,626   3,626   2,344
Prior 6,684   6,684   5,562
Revolving Loans 30,415   30,415   29,615
Revolving Loans Converted to Term Loans 145   145   148
Total 66,143   66,143   63,548
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]          
Year one     0    
Year two     10    
Year three     18    
Year four     9    
Year five     8    
Prior     8    
Revolving Loans     32    
Revolving Loans Converted to Term Loans     0    
Total     85    
Commercial and industrial | Pass          
Financing Receivable, Credit Quality Indicator [Line Items]          
Year one 6,787   6,787   9,462
Year two 8,417   8,417   6,640
Year three 5,539   5,539   4,075
Year four 3,315   3,315   4,086
Year five 3,285   3,285   2,203
Prior 6,176   6,176   5,059
Revolving Loans 29,143   29,143   28,124
Revolving Loans Converted to Term Loans 93   93   95
Total 62,755   62,755   59,744
Commercial and industrial | Criticized accrual          
Financing Receivable, Credit Quality Indicator [Line Items]          
Year one 49   49   216
Year two 222   222   337
Year three 370   370   479
Year four 405   405   390
Year five 266   266   116
Prior 349   349   348
Revolving Loans 1,125   1,125   1,355
Revolving Loans Converted to Term Loans 32   32   36
Total 2,818   2,818   3,277
Commercial and industrial | Criticized nonaccrual          
Financing Receivable, Credit Quality Indicator [Line Items]          
Year one 3   3   8
Year two 33   33   49
Year three 69   69   72
Year four 64   64   65
Year five 75   75   25
Prior 159   159   155
Revolving Loans 147   147   136
Revolving Loans Converted to Term Loans 20   20   17
Total 570   570   527
Commercial real estate          
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]          
Total 15 $ 25 33 $ 47  
Commercial real estate | Commercial          
Financing Receivable, Credit Quality Indicator [Line Items]          
Year one 2,888   2,888   3,781
Year two 3,302   3,302   429
Year three 422   422   1,822
Year four 1,833   1,833   1,950
Year five 1,936   1,936   1,250
Prior 10,465   10,465   10,592
Revolving Loans 388   388   368
Revolving Loans Converted to Term Loans 0   0   0
Total 21,234   21,234   20,192
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]          
Year one     0    
Year two     0    
Year three     0    
Year four     9    
Year five     2    
Prior     21    
Revolving Loans     0    
Revolving Loans Converted to Term Loans     0    
Total     32    
Commercial real estate | Commercial | Pass          
Financing Receivable, Credit Quality Indicator [Line Items]          
Year one 2,888   2,888   3,757
Year two 3,290   3,290   400
Year three 413   413   1,535
Year four 1,655   1,655   1,681
Year five 1,782   1,782   1,121
Prior 9,032   9,032   8,970
Revolving Loans 388   388   367
Revolving Loans Converted to Term Loans 0   0   0
Total 19,448   19,448   17,831
Commercial real estate | Commercial | Criticized accrual          
Financing Receivable, Credit Quality Indicator [Line Items]          
Year one 0   0   0
Year two 12   12   29
Year three 9   9   283
Year four 155   155   244
Year five 131   131   80
Prior 1,263   1,263   1,404
Revolving Loans 0   0   1
Revolving Loans Converted to Term Loans 0   0   0
Total 1,570   1,570   2,041
Commercial real estate | Commercial | Criticized nonaccrual          
Financing Receivable, Credit Quality Indicator [Line Items]          
Year one 0   0   24
Year two 0   0   0
Year three 0   0   4
Year four 23   23   25
Year five 23   23   49
Prior 170   170   218
Revolving Loans 0   0   0
Revolving Loans Converted to Term Loans 0   0   0
Total 216   216   320
Commercial real estate | Residential builder and developer          
Financing Receivable, Credit Quality Indicator [Line Items]          
Year one 47   47   9
Year two 18   18   1
Year three 2   2   2
Year four 0   0   14
Year five 11   11   0
Prior 4   4   5
Revolving Loans 28   28   38
Revolving Loans Converted to Term Loans 0   0   0
Total 110   110   69
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]          
Year one     0    
Year two     0    
Year three     0    
Year four     0    
Year five     0    
Prior     0    
Revolving Loans     0    
Revolving Loans Converted to Term Loans     0    
Total     0    
Commercial real estate | Residential builder and developer | Pass          
Financing Receivable, Credit Quality Indicator [Line Items]          
Year one 47   47   9
Year two 18   18   1
Year three 2   2   2
Year four 0   0   2
Year five 0   0   0
Prior 4   4   5
Revolving Loans 28   28   38
Revolving Loans Converted to Term Loans 0   0   0
Total 99   99   57
Commercial real estate | Residential builder and developer | Criticized accrual          
Financing Receivable, Credit Quality Indicator [Line Items]          
Year one 0   0   0
Year two 0   0   0
Year three 0   0   0
Year four 0   0   12
Year five 11   11   0
Prior 0   0   0
Revolving Loans 0   0   0
Revolving Loans Converted to Term Loans 0   0   0
Total 11   11   12
Commercial real estate | Residential builder and developer | Criticized nonaccrual          
Financing Receivable, Credit Quality Indicator [Line Items]          
Year one 0   0   0
Year two 0   0   0
Year three 0   0   0
Year four 0   0   0
Year five 0   0   0
Prior 0   0   0
Revolving Loans 0   0   0
Revolving Loans Converted to Term Loans 0   0   0
Total 0   0   0
Commercial real estate | Other commercial construction          
Financing Receivable, Credit Quality Indicator [Line Items]          
Year one 215   215   313
Year two 548   548   229
Year three 250   250   1,282
Year four 1,034   1,034   1,107
Year five 672   672   200
Prior 354   354   376
Revolving Loans 75   75   51
Revolving Loans Converted to Term Loans 0   0   0
Total 3,148   3,148   3,558
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]          
Year one     0    
Year two     0    
Year three     0    
Year four     0    
Year five     0    
Prior     1    
Revolving Loans     0    
Revolving Loans Converted to Term Loans     0    
Total     1    
Commercial real estate | Other commercial construction | Pass          
Financing Receivable, Credit Quality Indicator [Line Items]          
Year one 215   215   313
Year two 548   548   221
Year three 240   240   1,031
Year four 922   922   606
Year five 316   316   63
Prior 166   166   198
Revolving Loans 74   74   45
Revolving Loans Converted to Term Loans 0   0   0
Total 2,481   2,481   2,477
Commercial real estate | Other commercial construction | Criticized accrual          
Financing Receivable, Credit Quality Indicator [Line Items]          
Year one 0   0   0
Year two 0   0   8
Year three 10   10   251
Year four 112   112   493
Year five 349   349   136
Prior 159   159   174
Revolving Loans 1   1   6
Revolving Loans Converted to Term Loans 0   0   0
Total 631   631   1,068
Commercial real estate | Other commercial construction | Criticized nonaccrual          
Financing Receivable, Credit Quality Indicator [Line Items]          
Year one 0   0   0
Year two 0   0   0
Year three 0   0   0
Year four 0   0   8
Year five 7   7   1
Prior 29   29   4
Revolving Loans 0   0   0
Revolving Loans Converted to Term Loans 0   0   0
Total $ 36   $ 36   $ 13
[1] Loans of $3.1 billion and $2.1 billion at June 30, 2026 and December 31, 2025, respectively, were held in special purpose trusts to settle the respective obligations of asset-backed notes issued by those trusts. The outstanding balances of those asset-backed notes issued to third party investors were included in Long-term borrowings and were $2.8 billion at June 30, 2026 and $1.7 billion at December 31, 2025.