Shareholders' Equity (Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Balance	$ (1,676)
Balance	(1,196)
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Balance	(1,275)	$ (1,171)
Other comprehensive income	434	385
Equity method affiliates	16	43
Net current-period other comprehensive income	450	428
Balance	$ (825)	$ (743)