Stockholders' Equity - Changes in Each Component of AOCI of the Parent (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance,				$ (1,174)
Other comprehensive income (loss):
Other comprehensive income (loss) attributable to the parent company		$ (30)	$ 23	11	$ (60)
Balance,		(1,163)		(1,163)
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance,		(579)	(526)	(608)	(427)
Other comprehensive income (loss):
Currency translation adjustments		(24)	18	5	(83)
Holding gains and losses on net investment hedge			(4)		(2)
Other comprehensive income (loss) attributable to the parent company		(24)	14	5	(85)
Balance,		(603)	(512)	(603)	(512)
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance,		(1)	(10)	(4)	(9)
Other comprehensive income (loss):
Holding gains and losses		(14)	(3)	(13)	(9)
Reclassification of amount to net income	[1]	1	6	3	11
Other comprehensive income (loss) attributable to the parent company		(13)	3	(10)	2
Balance,		(14)	(7)	(14)	(7)
Accumulated Net Investment Gain (Loss) Attributable to Parent [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance,		4	6	2	5
Other comprehensive income (loss):
Holding gains and losses		1	(1)	3
Reclassification of amount to net income	[1]
Other comprehensive income (loss) attributable to the parent company		1	(1)	3	0
Balance,		5	5	5	5
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance,		(557)	(550)	(564)	(566)
Other comprehensive income (loss):
Reclassification adjustment for net actuarial losses included in net periodic benefit cost	[2]	6	7	13	13
Elimination of net prior service costs and actuarial losses of disposal group					10
Other comprehensive income (loss) attributable to the parent company		6	7	13	23
Balance,		(551)	(543)	(551)	(543)
AOCI Attributable to Parent [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance,		(1,133)	(1,080)	(1,174)	(997)
Other comprehensive income (loss):
Currency translation adjustments		(24)	18	5	(83)
Holding gains and losses on net investment hedge			(4)		(2)
Holding gains and losses		(13)	(4)	(10)	(9)
Reclassification of amount to net income	[1]	1	6	3	11
Reclassification adjustment for net actuarial losses included in net periodic benefit cost	[2]	6	7	13	13
Elimination of net prior service costs and actuarial losses of disposal group					10
Other comprehensive income (loss) attributable to the parent company		(30)	23	11	(60)
Balance,		$ (1,163)	$ (1,057)	$ (1,163)	$ (1,057)

[1] Foreign currency contract and investment reclassifications are included in other income, net.

[2] See Note 9 for additional details.