Netting Arrangements for Certain Financial Instruments and Securities Financing Activities - Summary of Maturities by Category of Collateral Pledged for Repurchase Agreements and Securities Loaned Transactions (Detail) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements	$ 2,559	$ 1,432
Securities loaned	182	120
Gross amount of recognized liabilities	2,741	1,552
Overnight and Continuous [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements	2,559	1,432
Securities loaned	182	120
Gross amount of recognized liabilities	2,741	1,552
U.S. Treasury and Agencies [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements	1,560	147
U.S. Treasury and Agencies [Member] | Overnight and Continuous [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements	1,560	147
Residential Mortgage-Backed Securities [Member] | Agency [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements	327	846
Residential Mortgage-Backed Securities [Member] | Overnight and Continuous [Member] | Agency [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements	327	846
Corporate Debt Securities [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements	672	439
Securities loaned	182	120
Corporate Debt Securities [Member] | Overnight and Continuous [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements	672	439
Securities loaned	$ 182	$ 120