Income Taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Current income tax expense included in consolidated statement of income, federal	$ 1,252	$ 477	$ 636
Current income tax expense included in consolidated statement of income, foreign	70	20	97
Current income tax expense included in consolidated statement of income, state	14	7	8
Total current tax expense	1,336	504	741
Deferred income tax expense (benefit) included in consolidated statement of income, federal	(152)	(163)	(186)
Deferred income tax expense (benefit) included in consolidated statement of income, foreign	(3)	39	(43)
Total deferred tax benefit	(155)	(124)	(229)
Total income tax expense included in the consolidated statement of income	1,181	380	512
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)	(79)	520	(2,002)
Total income tax expense (benefit) included in the consolidated financial statements	$ 1,102	$ 900	$ (1,490)