Income Taxes - Deferred Tax Valuation Allowance (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Deferred tax valuation allowance, rollfoward
Balance at beginning of year	$ 177
Balance at end of year	216	$ 177
Deferred tax asset valuation allowance
Deferred tax valuation allowance, rollfoward
Balance at beginning of year	177	149	$ 158
Charged to Income tax expense	39	28	(9)
Balance at end of year	$ 216	$ 177	$ 149