Income Taxes - Reconciliation of Income Taxes Computed at Statutory U.S. Federal Income Tax Rate to Income Tax Expense (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Income tax expense computed at the statutory U.S. federal income tax rate	$ (210)	$ (42)	$ 37
Increases (reductions) in income tax expense resulting from:
Foreign income taxed at different rates	2	8	19
Transition tax under Tax Cuts and Jobs Act ("TCJA")	0	0	11
State and local taxes on income, net of U.S. federal income tax benefit	(26)	(14)	(6)
Changes in valuation allowance for tax loss carryforwards and credits	605	36	0
Investment and R&D tax credits	(15)	(19)	(12)
Foreign earnings subject to U.S. federal income tax	18	12	13
Non-deductible expenses	15	16	3
Goodwill impairment and other non-deductible impairment	65	22	0
Tax contingencies	2	(7)	1
Gains on transfers of subsidiaries	0	21	0
Nonconsolidated affiliates	(10)	(8)	(4)
Other	13	(6)	1
Income tax expense	$ 459	$ 19	$ 63