Other Income, Net (Schedule of Foreign Exchange Gain (Loss)) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Foreign Currency Exchange Gain (Loss) [Line Items]
Net exchange (losses) gains	$ (59)	$ (121)
Net exchange (losses) gains, tax	66	68
Net exchange (losses) gains, after-tax	7	(53)
Subsidiary Monetary Position Gain (Loss) [Member]
Foreign Currency Exchange Gain (Loss) [Line Items]
Net exchange (losses) gains	26	33
Net exchange (losses) gains, tax	36	13
Net exchange (losses) gains, after-tax	62	46
Hedging Program Gain (Loss) [Member]
Foreign Currency Exchange Gain (Loss) [Line Items]
Net exchange (losses) gains	(85)	(154)
Net exchange (losses) gains, tax	30	55
Net exchange (losses) gains, after-tax	$ (55)	$ (99)