Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Balance at beginning of period	$ 8,052
Other comprehensive loss, net of tax	(134)	$ (671)	$ (444)
Balance at end of period	8,693	8,052
AOCI Attributable to Parent [Member]
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Balance at beginning of period	(1,104)	(433)	11
Balance at end of period	(1,238)	(1,104)	(433)
Unrealized Gain from Cash Flow Hedges [Member]
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Balance at beginning of period	0	0	0
Other comprehensive loss, net of tax	17	0	0
Balance at end of period	17	0	0
Defined Benefit Plans [Member]
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Balance at beginning of period	(13)	(11)	3
Other comprehensive loss, net of tax	(7)	(2)	(14)
Balance at end of period	(20)	(13)	(11)
Foreign Currency Translation Adjustment [Member]
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Balance at beginning of period	(1,091)	(422)	8
Other comprehensive loss, net of tax	(144)	(669)	(430)
Balance at end of period	$ (1,235)	$ (1,091)	$ (422)