Accumulated Other Comprehensive Income (Loss) - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Unrealized gains (losses) on investment securities:
Accumulated Other Comprehensive Income (Loss) [Line Items]
Tax on net unrealized gains (losses) arising during period	$ (244)	$ 298	$ 145
Tax on reclassification adjustment	(18)	(33)	(21)
Tax on reversal of provision for credit losses realized in net income (loss)	0	(1)	0
Tax on amortization of net unrealized losses on securities transferred from available-for-sale to held-to-maturity realized in net income (loss)	4	8	4
Unrealized gains (losses) on fair value option liabilities attributable to our own credit spread:
Accumulated Other Comprehensive Income (Loss) [Line Items]
Tax on net unrealized gains (losses) arising during period	4	8	(68)
Tax on reclassification adjustment			(30)
Unrealized gains (losses) on derivatives designated as cash flow hedges:
Accumulated Other Comprehensive Income (Loss) [Line Items]
Tax on net unrealized gains (losses) arising during period	(16)	20	(5)
Tax on reclassification adjustment	(3)	3	8
Pension and postretirement benefit liability:
Accumulated Other Comprehensive Income (Loss) [Line Items]
Tax on net unrealized gains (losses) arising during period	$ 1	(1)	$ (5)
Accounting Standards Update 2016-13 | Cumulative Effect, Period of Adoption, Adjustment | Unrealized gains (losses) on investment securities:
Accumulated Other Comprehensive Income (Loss) [Line Items]
Tax on cumulative effect adjustment		$ 1