Income Taxes - Provision for Federal & Foreign Income Tax Expense (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Federal income tax expense (benefit):
Current	$ 1,574	$ 1,618	$ 1,325
Deferred	(503)	(776)	(194)
Total federal income tax expense	1,071	842	1,131
Foreign income tax expense (benefit):
Current	102	87	93
Deferred	5	19	11
Total foreign income tax expense	107	106	104
Total federal and foreign income tax expense	$ 1,178	$ 948	$ 1,235