Federal Income Taxes - Federal Income Tax Expense (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Tax Expense (Benefit), Continuing Operations [Abstract]
Current	$ (3)	$ 3	$ 12
Deferred	(393)	364	853
Federal income tax expense (benefit)	$ (396)	$ 367	$ 865