Income Taxes - Unrecognized Tax Benefits, Including Attributable to Discontinued Operations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Income Tax Expense (Benefit) [Rollforward]
Balance at January 1	$ 35	$ 43
Additions based on tax positions related to current year	1	1
Additions for tax positions of prior years	1	2
Reductions for tax positions of prior years	(1)	(1)
Settlements and agreements	0	(4)
Lapse of statute of limitations	(4)	(6)
Balance at December 31	$ 32	$ 35