Income Taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Current income tax expense included in consolidated statement of income, federal	$ 477	$ 636	$ 659
Current income tax expense included in consolidated statement of income, foreign	20	97	67
Current income tax expense included in consolidated statement of income, state	7	8	6
Total current tax expense	504	741	732
Deferred income tax expense (benefit) included in consolidated statement of income, federal	(163)	(186)	62
Deferred income tax expense (benefit) included in consolidated statement of income, foreign	39	(43)	2
Total deferred tax expense (benefit)	(124)	(229)	64
Total income tax expense included in the consolidated statement of income	380	512	796
Expense (benefit) relating to changes in the unrealized gain (loss) on investments, unrealized loss on foreign exchange and other items in other comprehensive income (loss)	520	(2,002)	(362)
Total income tax expense (benefit) included in the consolidated financial statements	$ 900	$ (1,490)	$ 434