Federal Income Taxes - Federal Income Tax Expense (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Income Tax Expense (Benefit), Continuing Operations [Abstract]
Current	$ 6	$ (3)	$ 3
Deferred	741	(393)	364
Federal income tax expense (benefit)	$ 747	$ (396)	$ 367