Net Interest Income - Components of Interest Revenue and Interest Expenses (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Interest income:
Interest-bearing deposits with banks	$ (15)	$ 76	$ 416
Investment securities:
Investment securities available-for-sale	572	748	1,023
Investment securities held-to-maturity	665	829	974
Investment securities purchased under money market liquidity facility	4	117	0
Total Investment securities	1,241	1,694	1,997
Securities purchased under resale agreements	27	126	364
Loans	638	624	769
Other interest-earning assets	17	55	395
Total interest income	1,908	2,575	3,941
Interest expense:
Interest-bearing deposits	(263)	(117)	663
Short term borrowings under money market liquidity facility	4	101	0
Securities sold under repurchase agreements	0	4	31
Other short-term borrowings	2	17	21
Long-term debt	219	312	414
Other interest-bearing liabilities	41	58	246
Total interest expense	3	375	1,375
Net interest income	$ 1,905	$ 2,200	$ 2,566