Risk Management (Summary of Derivative Instruments and the Effect on the Condensed Consolidated Statements Of Operations) (Details) - Not Designated As Hedging Instruments - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Derivative Instruments	$ (56)	$ 7	$ (4)
Interest rate swap | Other income (expense)
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Derivative Instruments	1	1	1
Foreign exchange contracts | Other income (expense)
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Derivative Instruments	$ (57)	$ 6	$ (5)