Accounting for Transfers and Servicing of Financial Assets and Variable Interest Entities - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Variable Interest Entity [Line Items]
Assets related to consolidated VIEs	$ 600,973		$ 600,973		$ 573,284
Liabilities related to consolidated VIEs	552,995		552,995		517,897
Community Development And Tax Advantaged Investments [Member]
Variable Interest Entity [Line Items]
Federal and state income tax credits recognized in tax expense	111	$ 113	336	$ 356
Expense related to investments	102	101	310	333
Investment tax credits	117	75	292	235
Expenses related to investments recognized in tax expense	87	83	270	262
Financial Support Waived Fees [Member]
Variable Interest Entity [Line Items]
Financial or other support to money market funds		$ 67	65	$ 184
Variable Interest Entity Not Primary Beneficiary [Member] | Private Investment Funds and Partnerships [Member]
Variable Interest Entity [Line Items]
Maximum exposure to loss	87		87		84
Assets related to consolidated VIEs	48		48		40
Variable Interest Entity Not Primary Beneficiary [Member] | Community Development And Tax Advantaged Investments [Member]
Variable Interest Entity [Line Items]
Maximum exposure to loss	9,922		9,922		9,899
Assets related to consolidated VIEs	5,617		5,617		4,484
Liabilities related to consolidated VIEs	2,842		2,842		1,890
Variable Interest Entity Not Primary Beneficiary [Member] | Minimum [Member]
Variable Interest Entity [Line Items]
Aggregate amount of investments in unconsolidated VIEs	1		1		1
Variable Interest Entity Not Primary Beneficiary [Member] | Maximum [Member]
Variable Interest Entity [Line Items]
Aggregate amount of investments in unconsolidated VIEs	123		123		75
Variable Interest Entity Primary Beneficiary [Member] | Community Development And Tax Advantaged Investments [Member]
Variable Interest Entity [Line Items]
Assets related to consolidated VIEs	5,200		5,200		5,000
Liabilities related to consolidated VIEs	3,700		3,700		3,400
Variable Interest Entity Primary Beneficiary [Member] | Tender Option Bond Program [Member]
Variable Interest Entity [Line Items]
Assets related to consolidated VIEs	1,400		1,400		1,700
Liabilities related to consolidated VIEs	$ 1,500		$ 1,500		$ 1,200