v3.26.1
Loans - Summary of Criticized Assets for Commercial Loans (Detail) - USD ($)
$ in Millions
Jun. 30, 2026
Dec. 31, 2025
Financing Receivable, Credit Quality Indicator [Line Items]    
Total $ 62,103 $ 59,894
Commercial loans    
Financing Receivable, Credit Quality Indicator [Line Items]    
Current year 3,662 5,446
One year prior to current year 5,343 4,443
Two years prior to current year 3,312 2,011
Three years prior to current year 1,927 2,353
Four years prior to current year 1,114 1,245
Prior 4,961 7,147
Revolving Loans 21,343 15,648
Revolving Loans Converted to Term Loans 9 1,051
Total 41,671 39,344
Commercial loans | Commercial mortgages    
Financing Receivable, Credit Quality Indicator [Line Items]    
Current year 0 2
One year prior to current year 1 19
Two years prior to current year 19 237
Three years prior to current year 229 386
Four years prior to current year 138 34
Prior 557 761
Revolving Loans 0 0
Revolving Loans Converted to Term Loans 0 0
Total 944 1,439
Commercial loans | Business and corporate banking    
Financing Receivable, Credit Quality Indicator [Line Items]    
Current year 3,662 4,960
One year prior to current year 5,310 4,105
Two years prior to current year 3,229 1,687
Three years prior to current year 1,698 1,648
Four years prior to current year 971 873
Prior 4,391 5,194
Revolving Loans 11,656 8,787
Revolving Loans Converted to Term Loans 9 1,051
Total 30,926 28,305
Commercial loans | Other commercial    
Financing Receivable, Credit Quality Indicator [Line Items]    
Current year 0 484
One year prior to current year 32 319
Two years prior to current year 64 87
Three years prior to current year 0 319
Four years prior to current year 5 338
Prior 13 1,192
Revolving Loans 9,687 6,861
Revolving Loans Converted to Term Loans 0 0
Total 9,801 9,600
Commercial loans | Pass rated | Commercial mortgages    
Financing Receivable, Credit Quality Indicator [Line Items]    
Current year 0 2
One year prior to current year 1 18
Two years prior to current year 1 237
Three years prior to current year 229 266
Four years prior to current year 67 34
Prior 250 278
Revolving Loans 0 0
Revolving Loans Converted to Term Loans 0 0
Total 548 835
Commercial loans | Pass rated | Business and corporate banking    
Financing Receivable, Credit Quality Indicator [Line Items]    
Current year 3,623 4,634
One year prior to current year 5,065 3,496
Two years prior to current year 2,826 1,504
Three years prior to current year 1,625 1,486
Four years prior to current year 931 798
Prior 4,177 4,887
Revolving Loans 10,973 8,316
Revolving Loans Converted to Term Loans 7 1,040
Total 29,227 26,161
Commercial loans | Pass rated | Other commercial    
Financing Receivable, Credit Quality Indicator [Line Items]    
Current year 0 484
One year prior to current year 32 319
Two years prior to current year 64 87
Three years prior to current year 0 319
Four years prior to current year 5 338
Prior 13 1,192
Revolving Loans 9,687 6,861
Revolving Loans Converted to Term Loans 0 0
Total 9,801 9,600
Commercial loans | Criticized | Commercial mortgages    
Financing Receivable, Credit Quality Indicator [Line Items]    
Current year 0 0
One year prior to current year 0 1
Two years prior to current year 18 0
Three years prior to current year 0 120
Four years prior to current year 71 0
Prior 307 483
Revolving Loans 0 0
Revolving Loans Converted to Term Loans 0 0
Total 396 604
Commercial loans | Criticized | Business and corporate banking    
Financing Receivable, Credit Quality Indicator [Line Items]    
Current year 39 326
One year prior to current year 245 609
Two years prior to current year 403 183
Three years prior to current year 73 162
Four years prior to current year 40 75
Prior 214 307
Revolving Loans 683 471
Revolving Loans Converted to Term Loans 2 11
Total $ 1,699 $ 2,144