Derivatives and Hedging Activities - Additional Information (Details) $ in Millions	9 Months Ended
	Sep. 30, 2022 USD ($) derivative rating	Dec. 31, 2021 USD ($) rating
Credit Derivatives [Line Items]
Derivative assets after effects of bilateral collateral and master netting agreements	$ 66
Derivative liabilities after effects of bilateral collateral and master netting agreements	10
Derivative assets not designated as hedging instruments after effects of bilateral collateral and master netting agreements, and a reserve for potential future losses	1,500
Derivative liabilities not designated as hedging instruments after effects of bilateral collateral and master netting agreements, and a reserve for potential future losses	1,600
Reclassify of after-tax net gains on derivative instruments from AOCI	$ (566)
Length of time hedge in cash flow hedge (in months)	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 (in years)	4 years 11 months 1 day
Cash collateral netted against derivative assets	$ (31)	$ 100
Collateral netted against derivative liabilities	1,200	1,100
Gross exposure on derivatives, after taking into account the effects of bilateral collateral and master netting agreements	443
Net exposure on derivatives, after taking into account, the effects of bilateral collateral and master netting agreements	244
Over-collateralization on derivatives to broker-dealers and banks, after the application of master netting agreements and collateral	243
Additional collateral held in the form of securities	1
Default reserve associated with uncollateralized contracts	25
Gross exposure on derivatives after taking into account effects of master netting agreements	1,500
Net exposure on derivatives with clients after application of master netting agreements collateral and related reserve	1,400
Net liability position totaled	3	$ 11
Banking Subsidiary
Credit Derivatives [Line Items]
Net liability position totaled	1,100
Derivative assets included in net liability position	315
Derivative liabilities included in net liability position	1,400
Cash and securities collateral posted	$ 1,100
Number of credit risk derivatives held | derivative	0
Banking Subsidiary | Unsecured Debt
Credit Derivatives [Line Items]
Number of ratings above noninvestment | rating	3	3
Banking Subsidiary | Unsecured Debt | Maximum
Credit Derivatives [Line Items]
Payments to terminate contracts (less than for the $1 million)	$ 2	$ 4