Business Segment Information - Segments' Total Assets (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023	Sep. 30, 2023
Segments’ total assets
Total assets	$ 3,324,293	$ 3,180,151	$ 3,153,090
Operating Segments
Segments’ total assets
Total assets	2,964,287		2,849,187
Asset and liability management activities, including securities portfolio
Segments’ total assets
Total assets	1,251,025		1,185,910
Other
Segments’ total assets
Total assets	62,599		63,708
Elimination of segment asset allocations to match liabilities
Segments’ total assets
Total assets	$ (953,618)		$ (945,715)