Derivatives and Hedging Activities - Additional Information (Details) $ in Millions	3 Months Ended
	Mar. 31, 2022 USD ($) rating derivative	Dec. 31, 2021 USD ($) rating
Credit Derivatives [Line Items]
Derivative assets after effects of bilateral collateral and master netting agreements	$ 99
Derivative liabilities after effects of bilateral collateral and master netting agreements	(11)
Derivative assets not designated as hedging instruments after effects of bilateral collateral and master netting agreements, and a reserve for potential future losses	2,600
Derivative liabilities not designated as hedging instruments after effects of bilateral collateral and master netting agreements, and a reserve for potential future losses	609
Reclassify of after-tax net gains on derivative instruments from AOCI	$ (124)
Length of time hedge in cash flow hedge	12 months
Reclassification of net losses related to terminated cash flow hedges from AOCI to income	$ (3)
Maximum length of time over which forecasted transactions are hedged, years	5 years 5 months 1 day
Cash collateral netted against derivative assets	$ 149	$ 100
Collateral netted against derivative liabilities	2,200	1,100
Gross exposure on derivatives, after taking into account the effects of bilateral collateral and master netting agreements	209
Net exposure on derivatives, after taking into account, the effects of bilateral collateral and master netting agreements	305
Over-collateralization on derivatives to broker-dealers and banks, after the application of master netting agreements and collateral	303
Additional collateral held in the form of securities	2
Default reserve associated with uncollateralized contracts	19
Gross exposure on derivatives after taking into account effects of master netting agreements	2,600
Net exposure on derivatives with clients after application of master netting agreements collateral and related reserve	2,400
Net liability position totaled	5	$ 11
Banking Subsidiary
Credit Derivatives [Line Items]
Net liability position totaled	2,300
Derivative assets included in net liability position	265
Derivative liabilities included in net liability position	2,600
Cash and securities collateral posted	$ 2,300
Number of credit risk derivatives held | derivative	0
Banking Subsidiary | Unsecured Debt
Credit Derivatives [Line Items]
Number of ratings above noninvestment | rating	4	4
Banking Subsidiary | Maximum | Unsecured Debt
Credit Derivatives [Line Items]
Payments to terminate contracts (less than for the $1 million)	$ 4	$ 4