Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Income Tax Disclosure [Abstract]
Tax (benefit)	$ 12	$ 82	$ 55	$ 115
(Loss) income from continuing operations before income taxes	(3)	$ 302	154	$ 476
Disproportionate tax effect related to termination of pension plans	$ 11		$ 11
Effective tax rate (as a percent)		27.00%	36.00%	24.00%
Income tax expense, elimination of disproportionate tax			$ 5
Change in deferred tax assets valuation allowance		$ 2
Income tax expense on stock-based compensation				$ 7
Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Amount				$ 6