Accounting for Transfers and Servicing of Financial Assets and Variable Interest Entities - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Variable Interest Entity [Line Items]
Assets related to consolidated VIEs	$ 591,381		$ 591,381		$ 573,284
Liabilities related to consolidated VIEs	542,312		542,312		517,897
Community Development And Tax Advantaged Investments [Member]
Variable Interest Entity [Line Items]
Federal and state income tax credits recognized in tax expense	112	$ 110	225	$ 243
Expense related to investments	106	106	208	232
Investment tax credits	162	123	175	160
Expenses related to investments recognized in tax expense	92	87	183	179
Financial Support Waived Fees [Member]
Variable Interest Entity [Line Items]
Financial or other support to money market funds	7	$ 70	65	$ 117
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	46		46		40
Variable Interest Entity Not Primary Beneficiary [Member] | Community Development And Tax Advantaged Investments [Member]
Variable Interest Entity [Line Items]
Maximum exposure to loss	9,872		9,872		9,899
Assets related to consolidated VIEs	4,999		4,999		4,484
Liabilities related to consolidated VIEs	2,210		2,210		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	105		105		75
Variable Interest Entity Primary Beneficiary [Member] | Community Development And Tax Advantaged Investments [Member]
Variable Interest Entity [Line Items]
Assets related to consolidated VIEs	4,900		4,900		5,000
Liabilities related to consolidated VIEs	3,300		3,300		3,400
Variable Interest Entity Primary Beneficiary [Member] | Tender Option Bond Program [Member]
Variable Interest Entity [Line Items]
Assets related to consolidated VIEs	1,500		1,500		1,700
Liabilities related to consolidated VIEs	$ 1,200		$ 1,200		$ 1,200