Net Interest Income (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Interest income:
Interest-bearing deposits with banks	$ 929	$ 696	$ 1,927	$ 1,338
Investment securities:
Investment securities available-for-sale	672	408	1,244	755
Investment securities held-to-maturity	277	320	571	640
Total investment securities	949	728	1,815	1,395
Securities purchased under resale agreements	166	81	333	157
Loans	563	442	1,109	839
Other interest-earning assets	391	285	703	530
Total interest income	2,998	2,232	5,887	4,259
Interest expense:
Interest-bearing deposits	1,637	1,193	3,277	2,147
Securities sold under repurchase agreements	43	13	82	22
Short-term borrowings	167	20	268	32
Long-term debt	267	209	525	393
Other interest-bearing liabilities	149	106	284	208
Total interest expense	2,263	1,541	4,436	2,802
Net interest income	$ 735	$ 691	$ 1,451	$ 1,457