Business Segment Information - Segments' Total Assets (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022	Sep. 30, 2022
Segments’ total assets
Total assets	$ 3,153,090	$ 3,051,375	$ 3,072,953
Operating Segments
Segments’ total assets
Total assets	2,849,187		2,944,902
Asset and liability management activities
Segments’ total assets
Total assets	1,185,910		1,129,824
Other
Segments’ total assets
Total assets	63,708		63,284
Elimination of segment asset allocations to match liabilities
Segments’ total assets
Total assets	$ (945,715)		$ (1,065,057)