Income Taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Current income tax expense included in consolidated statement of income, federal	$ 659	$ 532	$ 546
Current income tax expense included in consolidated statement of income, foreign	67	35	7
Current income tax expense included in consolidated statement of income, state	6	4	6
Total current tax expense	732	571	559
Deferred income tax expense (benefit) included in consolidated statement of income, federal	62	(29)	(33)
Deferred income tax expense (benefit) included in consolidated statement of income, foreign	2	(2)	(10)
Total deferred tax expense (benefit)	64	(31)	(43)
Total income tax expense included in the consolidated statement of income	796	540	516
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)	(362)	490	641
Total income tax expense included in the consolidated financial statements	$ 434	$ 1,030	$ 1,157