Business Segment Information - Segments' Total Assets (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021
Segments’ total assets
Total assets	$ 3,238,223	$ 3,169,495	$ 2,969,992
Operating Segments
Segments’ total assets
Total assets	3,106,037		2,765,983
Asset and liability management activities
Segments’ total assets
Total assets	1,281,639		1,226,930
Other
Segments’ total assets
Total assets	66,948		63,347
Elimination of segment asset allocations to match liabilities
Segments’ total assets
Total assets	$ (1,216,401)		$ (1,086,268)