Other Income, Net (Schedule of Foreign Exchange Gain (Loss)) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Foreign Currency Exchange Gain (Loss) [Line Items]
Net exchange (losses) gains	$ (106)	$ 30	$ 196
Net exchange gains (losses), tax	(16)	(218)	(419)
Net exchange gains (losses), after-tax	(122)	(188)	(223)
Subsidiaries [Member]
Foreign Currency Exchange Gain (Loss) [Line Items]
Net exchange (losses) gains	198	(404)	(411)
Net exchange gains (losses), tax	(126)	(61)	(207)
Net exchange gains (losses), after-tax	72	(465)	(618)
Hedging Program [Member]
Foreign Currency Exchange Gain (Loss) [Line Items]
Net exchange (losses) gains	(304)	434	607
Net exchange gains (losses), tax	110	(157)	(212)
Net exchange gains (losses), after-tax	$ (194)	$ 277	$ 395