Income Taxes (Unaudited) (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Income Tax Disclosure [Abstract]
Consolidated effective income tax rate (percent)			35.00%	38.00%
Schedule Of Income Taxes [Line Items]
U.S. operations	$ 5,000,000	$ 29,000,000	$ 8,000,000	$ 22,000,000
International operations	(520,000,000)	(215,000,000)	(1,029,000,000)	(382,000,000)
Total	(515,000,000)	(186,000,000)	(1,021,000,000)	(360,000,000)
Tax Cuts and Jobs Act of 2017, Measurement Period Adjustment, Income Tax Expense (Benefit)			0
Income Tax Examination, Liability (Refund) Adjustment from Settlement with Taxing Authority	$ 5,000,000		$ 5,000,000
Minimum Tax Credit Carryforwards [Member]
Schedule Of Income Taxes [Line Items]
U.S. operations		$ (32,000,000)		$ (31,000,000)