Income Taxes (Net Deferred Tax Asset (Liability)) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Noncurrent deferred tax asset	$ 33	$ 38
Noncurrent deferred tax liability	(481)	(577)
Net deferred tax liability	$ (448)	$ (539)

Amount after allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards classified as noncurrent.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant