Derivatives and Hedging Activities - Narrative (Details) $ in Millions	9 Months Ended
	Sep. 30, 2023 USD ($) group	Dec. 31, 2022 USD ($)
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative assets after effects of bilateral collateral and master netting agreements	$ 18
Derivative liabilities after effects of bilateral collateral and master netting agreements (less than)	1
Derivative assets not designated as hedging instruments after effects of bilateral collateral and master netting agreements, and a reserve for potential future losses	404
Derivative liabilities not designated as hedging instruments after effects of bilateral collateral and master netting agreements, and a reserve for potential future losses	1,700
Reclassify of after-tax net losses on derivative instruments from AOCI	588
Reclassification of net losses related to terminated cash flow hedges from AOCI to income	$ 4
Maximum length of time over which forecasted transactions are hedged (in years)	4 years 3 months 7 days
Cash collateral netted against derivative assets	$ 239	$ 10
Collateral netted against derivative liabilities	$ 285	626
Number of derivative transactions group | group	2
Gross exposure on derivatives, after taking into account the effects of bilateral collateral and master netting agreements	$ 474
Net exposure on derivatives, after taking into account, the effects of bilateral collateral and master netting agreements	32
Default reserve associated with uncollateralized contracts	6
Gross exposure on derivatives after taking into account effects of master netting agreements	470
Net exposure on derivatives with clients after application of master netting agreements collateral and related reserve	391
Net liability position	$ 3	$ 2