Income Taxes - Components of Income Tax Expense (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Current tax expense (benefit):
Federal	$ 14	$ 0	$ (45)
Deferred tax expense (benefit):
Federal	(1)	(51)	201
Total deferred tax expense (benefit)	(1)	(51)	201
Income tax expense (benefit)	$ 13	$ (51)	$ 156