Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance			$ 37,203
Other comprehensive income (loss) before reclassifications	$ (3)	$ (61)	37	$ (99)
Amounts reclassified from accumulated other comprehensive income(2)	1	0	2	0
Net other comprehensive income (loss)	(2)	(61)	39	(99)
Ending balance	35,954		35,954
Accumulated Translation Adjustment
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(125)	(104)	(165)	(65)
Other comprehensive income (loss) before reclassifications	(3)	(61)	37	(100)
Amounts reclassified from accumulated other comprehensive income(2)	0	0	0	0
Net other comprehensive income (loss)	(3)	(61)	37	(100)
Ending balance	(128)	(165)	(128)	(165)
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 (loss) before reclassifications	0	0	0	1
Amounts reclassified from accumulated other comprehensive income(2)	1	0	2	0
Net other comprehensive income (loss)	1	0	2	1
Ending balance	(5)	(8)	(5)	(8)
Defined Benefit Pension Items
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(186)	(143)	(186)	(143)
Other comprehensive income (loss) before reclassifications	0	0	0	0
Amounts reclassified from accumulated other comprehensive income(2)	0	0	0	0
Net other comprehensive income (loss)	0	0	0	0
Ending balance	(186)	(143)	(186)	(143)
AOCI
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(317)	(255)	(358)	(217)
Ending balance	$ (319)	$ (316)	$ (319)	$ (316)