Loans - Summary of Past Due Loans (Detail) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Financing Receivable, Past Due [Line Items]
Carrying Value	$ 239,882	$ 200,866
Total divided by gross loans at amortized cost	0.40%	0.70%
Corporate
Financing Receivable, Past Due [Line Items]
Carrying Value	$ 30,676	$ 29,972
Commercial real estate
Financing Receivable, Past Due [Line Items]
Carrying Value	37,409	29,789
Residential real estate
Financing Receivable, Past Due [Line Items]
Carrying Value	31,957	25,969
Securities-based
Financing Receivable, Past Due [Line Items]
Carrying Value	18,079	16,477
Other collateralized
Financing Receivable, Past Due [Line Items]
Carrying Value	98,999	75,107
Credit cards
Financing Receivable, Past Due [Line Items]
Carrying Value	19,742	21,403
Other
Financing Receivable, Past Due [Line Items]
Carrying Value	3,020	2,149
Past due
Financing Receivable, Past Due [Line Items]
Carrying Value	770	1,392
Past due \| Corporate
Financing Receivable, Past Due [Line Items]
Carrying Value	32	15
Past due \| Commercial real estate
Financing Receivable, Past Due [Line Items]
Carrying Value	617	472
Past due \| Residential real estate
Financing Receivable, Past Due [Line Items]
Carrying Value	22	21
Past due \| Securities-based
Financing Receivable, Past Due [Line Items]
Carrying Value	2	6
Past due \| Other collateralized
Financing Receivable, Past Due [Line Items]
Carrying Value	63	5
Past due \| Credit cards
Financing Receivable, Past Due [Line Items]
Carrying Value		873
Past due \| Other
Financing Receivable, Past Due [Line Items]
Carrying Value	34
30-89 days
Financing Receivable, Past Due [Line Items]
Carrying Value	398	612
30-89 days \| Corporate
Financing Receivable, Past Due [Line Items]
Carrying Value	0	0
30-89 days \| Commercial real estate
Financing Receivable, Past Due [Line Items]
Carrying Value	336	186
30-89 days \| Residential real estate
Financing Receivable, Past Due [Line Items]
Carrying Value	3	3
30-89 days \| Securities-based
Financing Receivable, Past Due [Line Items]
Carrying Value	2	6
30-89 days \| Other collateralized
Financing Receivable, Past Due [Line Items]
Carrying Value	57	0
30-89 days \| Credit cards
Financing Receivable, Past Due [Line Items]
Carrying Value		417
30-89 days \| Other
Financing Receivable, Past Due [Line Items]
Carrying Value	0
90 days or more
Financing Receivable, Past Due [Line Items]
Carrying Value	372	780
90 days or more \| Corporate
Financing Receivable, Past Due [Line Items]
Carrying Value	32	15
90 days or more \| Commercial real estate
Financing Receivable, Past Due [Line Items]
Carrying Value	281	286
90 days or more \| Residential real estate
Financing Receivable, Past Due [Line Items]
Carrying Value	19	18
90 days or more \| Securities-based
Financing Receivable, Past Due [Line Items]
Carrying Value	0	0
90 days or more \| Other collateralized
Financing Receivable, Past Due [Line Items]
Carrying Value	6	5
90 days or more \| Credit cards
Financing Receivable, Past Due [Line Items]
Carrying Value		$ 456
90 days or more \| Other
Financing Receivable, Past Due [Line Items]
Carrying Value	$ 34