Other Assets - Schedule of Other Assets (Detail) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Accrued interest receivable	$ 2,081	$ 2,031
Benefit and insurance-related investments	460	452
Income tax asset, net	122	132
Derivatives at fair value	55	56
Accounts receivable	101	83
Fixed assets	62	74
Other	33	38
Total	$ 2,914	$ 2,866