Net Interest Income (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Interest income:
Interest-bearing deposits with banks	$ 70	$ (4)	$ 79	$ (13)
Investment securities:
Investment securities available-for-sale	122	145	276	285
Investment securities held-to-maturity	230	163	401	343
Investment securities purchased under money market liquidity facility	0	0	0	4
Total investment securities	352	308	677	632
Securities purchased under resale agreements	38	3	48	13
Loans	199	157	371	298
Other interest-earning assets	45	3	50	8
Total interest income	704	467	1,225	938
Interest expense:
Interest-bearing deposits	23	(65)	(40)	(134)
Short-term borrowings under money market liquidity facility	0	0	0	4
Securities sold under repurchase agreements	3	0	3	0
Other short-term borrowings	1	1	1	1
Long-term debt	72	54	137	114
Other interest-bearing liabilities	21	10	31	19
Interest expense	120	0	132	4
Net interest income	$ 584	$ 467	$ 1,093	$ 934