Securitization Activities - Firms Continuing Involvement in Securitization Entities to Which Firm Sold Assets (Detail) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Qualitative and Quantitative Information, Transferor's Continuing Involvement [Line Items]
Outstanding Principal Amount	$ 136,562	$ 115,351
Retained Interests	4,908	3,552
Purchased Interests	271	266
Fair value of retained interests	4,830	3,570
U.S. government agency-issued CMOs
Qualitative and Quantitative Information, Transferor's Continuing Involvement [Line Items]
Outstanding Principal Amount	39,848	33,984
Retained Interests	1,899	955
Purchased Interests	0	3
Other residential mortgage-backed
Qualitative and Quantitative Information, Transferor's Continuing Involvement [Line Items]
Outstanding Principal Amount	27,703	23,262
Retained Interests	1,233	1,114
Purchased Interests	129	96
Other commercial mortgage-backed
Qualitative and Quantitative Information, Transferor's Continuing Involvement [Line Items]
Outstanding Principal Amount	59,919	50,350
Retained Interests	1,351	1,123
Purchased Interests	108	130
Corporate debt and other asset-backed
Qualitative and Quantitative Information, Transferor's Continuing Involvement [Line Items]
Outstanding Principal Amount	9,092	7,755
Retained Interests	425	360
Purchased Interests	$ 34	$ 37