Stockholders' Equity (Deficit) (Components of Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Unrealized translation - Beginning balance	$ (2,252)	$ (1,335)
Other comprehensive income/(loss) before reclassifications	200	(465)
(Income)/loss reclassified from AOCI	0	0
Unrealized currency translation adjustments	208	(468)
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax	(6)	8
Unrealized translation - Ending balance	(2,052)	(1,812)
Other	(19)	20
Shares purchased from noncontrolling interest and other		0
Pension Plan
Defined benefit and other postretirement benefit plans - Beginning balance	(1,013)	(1,924)
Other comprehensive income/(loss) before reclassifications	(12)	(8)
(Income)/loss reclassified from AOCI	7	14
Defined benefit and other postretirement benefit plans - Ending balance	(1,018)	(1,918)
Other Postretirement Benefit Plans, Defined Benefit
Defined benefit and other postretirement benefit plans - Beginning balance	(3)	(37)
Other comprehensive income/(loss) before reclassifications	0	2
(Income)/loss reclassified from AOCI	0	0
Defined benefit and other postretirement benefit plans - Ending balance	(3)	(35)
Parent
Unrealized currency translation adjustments	200	(465)
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax	(5)
Other	(19)
Shares purchased from noncontrolling interest and other		(12)
Parent | Pension Plan
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax	(5)	6
Shares purchased from noncontrolling interest and other		0
Parent | Other Postretirement Benefit Plans, Defined Benefit
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax	0	2
Shares purchased from noncontrolling interest and other		0
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent
Cash flow hedge and other - Beginning balance	(10)	(16)
Other comprehensive income/(loss) before reclassifications	(13)	37
Income/loss reclassified from AOCI	(6)	(17)
Cash flow hedge and other - Ending balance	(29)	4
Other	$ (19)	$ 20