Shareholders' Equity (Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Balance			$ (1,676)
Balance	$ (1,201)		(1,201)
Other Comprehensive Income (Loss), Equity Method Investments, Tax		$ 19		$ 19
Foreign Currency Transaction Gain (Loss), Tax	(16)	41	0	17
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Balance	(825)	(743)	(1,275)	(1,171)
Other comprehensive income	(49)	240	385	625
Equity method affiliates	3	(44)	19	(1)
Net current-period other comprehensive income	(46)	196	404	624
Balance	(871)	(547)	(871)	(547)
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Balance	(346)	(588)	(347)	(588)
Other comprehensive income	(1)	(29)		(35)
Amounts reclassified from accumulated other comprehensive income	17	29	17	36
Equity method affiliates		265		264
Net current-period other comprehensive income	16	265	17	265
Balance	(330)	$ (323)	(330)	$ (323)
Amounts reclassified from accumulated other comprehensive income, Tax	$ 9		$ 10