Net Interest Income - Components of Interest Revenue and Interest Expense (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Interest income:
Interest-bearing deposits with banks	$ 3,634	$ 2,869	$ 842
Investment securities:
Investment securities available-for-sale	2,680	1,744	724
Investment securities held-to-maturity	1,090	1,262	979
Total investment securities	3,770	3,006	1,703
Securities purchased under resale agreements	686	312	188
Loans	2,271	1,862	972
Other interest-earning assets	1,616	1,131	383
Total interest income	11,977	9,180	4,088
Interest expense:
Interest-bearing deposits	6,627	4,991	967
Securities sold under repurchase agreements	156	34	14
Federal funds purchased	0	3	0
Short-term borrowings	577	40	26
Long-term debt	1,086	888	376
Other interest-bearing liabilities	608	465	161
Total interest expense	9,054	6,421	1,544
Net interest income	$ 2,923	$ 2,759	$ 2,544