Securities - Narrative (Details) - USD ($) $ in Millions			3 Months Ended		6 Months Ended
	Jun. 30, 2022	Dec. 31, 2021	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2022	Jun. 30, 2021
Debt Securities, Available-for-sale [Line Items]
Available-for-sale securities transferred to held-to-maturity					$ 906	$ 5,945
Debt securities, available-for-sale and held-to-maturity, allowance for credit loss	$ 10	$ 10	$ 10		$ 10
AOCI, transfers from AFS to HTM Securities, gross unrealized losses	$ (200)	$ 75
Agency RMBS, U.S. Government Agencies and Commercial MBS
Debt Securities, Available-for-sale [Line Items]
AOCI, transfers from AFS to HTM Securities, gross unrealized losses, amortized cost			975	$ 5,300
Available-for-sale securities transferred to held-to-maturity			$ 906	$ 5,200