Net Interest Income (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Interest income:
Interest-bearing deposits with banks	$ 998	$ 641
Investment securities:
Investment securities available-for-sale	572	347
Investment securities held-to-maturity	294	321
Total investment securities	866	668
Securities purchased under resale agreements	167	76
Loans	546	397
Other interest-earning assets	312	245
Total interest income	2,889	2,027
Interest expense:
Interest-bearing deposits	1,640	953
Securities sold under repurchase agreements	39	9
Short-term borrowings	101	12
Long-term debt	258	184
Other interest-bearing liabilities	135	103
Interest expense	2,173	1,261
Net interest income	$ 716	$ 766