Loans - Wholesale Loan Portfolio, Geographic Distribution and Delinquency (Details) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Financing Receivable, Past Due [Line Items]
Retained loans	$ 1,408,905	$ 1,299,590	$ 1,280,870
Wholesale
Financing Receivable, Past Due [Line Items]
Retained loans	792,367	690,396	$ 672,472
Wholesale | Criticized nonaccrual
Financing Receivable, Past Due [Line Items]
Retained loans	4,398	3,942
Wholesale | Current
Financing Receivable, Past Due [Line Items]
Retained loans	784,998	683,244
Wholesale | 30–89 days past due and still accruing
Financing Receivable, Past Due [Line Items]
Retained loans	2,913	2,938
Wholesale | 90 or more days past due and still accruing
Financing Receivable, Past Due [Line Items]
Retained loans	58	272
Wholesale | Total U.S.
Financing Receivable, Past Due [Line Items]
Retained loans	626,060	564,912
Wholesale | Total non-U.S.
Financing Receivable, Past Due [Line Items]
Retained loans	166,307	125,484
Secured by real estate | Wholesale
Financing Receivable, Past Due [Line Items]
Retained loans	165,545	162,432
Secured by real estate | Wholesale | Criticized nonaccrual
Financing Receivable, Past Due [Line Items]
Retained loans	1,678	1,439
Secured by real estate | Wholesale | Current
Financing Receivable, Past Due [Line Items]
Retained loans	163,189	159,949
Secured by real estate | Wholesale | 30–89 days past due and still accruing
Financing Receivable, Past Due [Line Items]
Retained loans	636	918
Secured by real estate | Wholesale | 90 or more days past due and still accruing
Financing Receivable, Past Due [Line Items]
Retained loans	42	126
Secured by real estate | Wholesale | Total U.S.
Financing Receivable, Past Due [Line Items]
Retained loans	162,378	159,209
Secured by real estate | Wholesale | Total non-U.S.
Financing Receivable, Past Due [Line Items]
Retained loans	3,167	3,223
Commercial and industrial | Wholesale
Financing Receivable, Past Due [Line Items]
Retained loans	174,403	166,790
Commercial and industrial | Wholesale | Criticized nonaccrual
Financing Receivable, Past Due [Line Items]
Retained loans	1,954	1,760
Commercial and industrial | Wholesale | Current
Financing Receivable, Past Due [Line Items]
Retained loans	171,227	164,104
Commercial and industrial | Wholesale | 30–89 days past due and still accruing
Financing Receivable, Past Due [Line Items]
Retained loans	1,220	868
Commercial and industrial | Wholesale | 90 or more days past due and still accruing
Financing Receivable, Past Due [Line Items]
Retained loans	2	58
Commercial and industrial | Wholesale | Total U.S.
Financing Receivable, Past Due [Line Items]
Retained loans	131,945	127,626
Commercial and industrial | Wholesale | Total non-U.S.
Financing Receivable, Past Due [Line Items]
Retained loans	42,458	39,164
Other | Wholesale
Financing Receivable, Past Due [Line Items]
Retained loans	452,419	361,174
Other | Wholesale | Criticized nonaccrual
Financing Receivable, Past Due [Line Items]
Retained loans	766	743
Other | Wholesale | Current
Financing Receivable, Past Due [Line Items]
Retained loans	450,582	359,191
Other | Wholesale | 30–89 days past due and still accruing
Financing Receivable, Past Due [Line Items]
Retained loans	1,057	1,152
Other | Wholesale | 90 or more days past due and still accruing
Financing Receivable, Past Due [Line Items]
Retained loans	14	88
Other | Wholesale | Total U.S.
Financing Receivable, Past Due [Line Items]
Retained loans	331,737	278,077
Other | Wholesale | Total non-U.S.
Financing Receivable, Past Due [Line Items]
Retained loans	$ 120,682	$ 83,097