Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance			$ 37,203
Net other comprehensive income	$ 22	$ 9	41	$ (38)
Ending balance	34,766		34,766
Accumulated Translation Adjustment
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(147)	(113)	(165)	(65)
Other comprehensive income before reclassifications	22	9	40	(39)
Amounts reclassified from accumulated other comprehensive income(2)	0	0	0	0
Net other comprehensive income	22	9	40	(39)
Ending balance	(125)	(104)	(125)	(104)
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(6)	(8)	(7)	(9)
Other comprehensive income before reclassifications	0	0	0	0
Amounts reclassified from accumulated other comprehensive income(2)	0	0	1	1
Net other comprehensive income	0	0	1	1
Ending balance	(6)	(8)	(6)	(8)
Defined Benefit Pension Items
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(186)	(143)	(186)	(143)
Other comprehensive income before reclassifications	0	0	0	0
Amounts reclassified from accumulated other comprehensive income(2)	0	0	0	0
Net other comprehensive income	0	0	0	0
Ending balance	(186)	(143)	(186)	(143)
AOCI
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(339)	(264)	(358)	(217)
Other comprehensive income before reclassifications	22	9	40	(39)
Amounts reclassified from accumulated other comprehensive income(2)	0	0	1	1
Net other comprehensive income	22	9	41	(38)
Ending balance	$ (317)	$ (255)	$ (317)	$ (255)