Equity (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		57 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2015
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	$ 7,325	$ 7,651
Net income	254	66
Total foreign currency translation adjustment, net of income tax	(421)	11
Total change in derivative fair value, net of income tax	(60)	(101)
Total pension adjustments, net of income tax	5	6
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets	(5)	0	(5)
Capital contributions from noncontrolling interests	67	31
Distributions to noncontrolling interests	(19)	(24)
Disposition of businesses	0	(5)
Acquisition of treasury stock	(35)	0	(1,300)
Issuance and exercise of stock-based compensation benefit plans, net of income tax	5	6
Sale of subsidiary shares to noncontrolling interests	(81)	0
Ending Balance	7,035	7,641	7,035
Common Stock, Dividends, Per Share, Declared	$ 0.00	$ 0.00
Common Stock, Dividends, Per Share, Cash Paid	$ 0.10
Unrealized Derivative Losses [Roll Forward]
Unrealized derivative losses, beginning balance	(396)
Unrealized derivative losses, ending balance	(422)		(422)
Unfunded PensionObligation [Roll Forward]
Unfunded pension obligation, beginning balance	(295)
Unfunded pension obligation, ending balance	(294)		(294)
Foreign Currency Translation Adjustment [Roll Forward]
Foreign currency translation adjustment, beginning balance	(2,595)
Foreign currency translation adjustment, ending balance	(2,833)		(2,833)
Accumulated Other Comprehensive Income Loss Net Of Tax [Roll Forward]
Accumulated other comprehensive loss, beginning balance	(3,286)
Other comprehensive income before reclassifications	(286)
Amounts reclassified from accumulated other comprehensive loss	(10)
Accumulated other comprehensive loss, ending balance	(3,549)		(3,549)
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income Loss Net Of Tax [Roll Forward]
Other comprehensive income before reclassifications	(35)
Amounts reclassified from accumulated other comprehensive loss	(9)
Accumulated Translation Adjustment [Member]
Accumulated Other Comprehensive Income Loss Net Of Tax [Roll Forward]
Other comprehensive income before reclassifications	(251)
Amounts reclassified from accumulated other comprehensive loss	0
Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated Other Comprehensive Income Loss Net Of Tax [Roll Forward]
Other comprehensive income before reclassifications	0
Amounts reclassified from accumulated other comprehensive loss	(1)
Parent [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	4,272	4,330
Net income	142	(58)
Total foreign currency translation adjustment, net of income tax	(251)	(40)
Total change in derivative fair value, net of income tax	(26)	(47)
Total pension adjustments, net of income tax	1	2
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets	(5)	0	(5)
Capital contributions from noncontrolling interests	0	0
Distributions to noncontrolling interests	0	0
Disposition of businesses	0	0
Acquisition of treasury stock	(35)	0
Issuance and exercise of stock-based compensation benefit plans, net of income tax	5	6
Sale of subsidiary shares to noncontrolling interests	(81)	0
Ending Balance	4,022	4,193	4,022
Noncontrolling Interest [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	3,053	3,321
Net income	112	124
Total foreign currency translation adjustment, net of income tax	(170)	51
Total change in derivative fair value, net of income tax	(34)	(54)
Total pension adjustments, net of income tax	4	4
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets	0	0	0
Capital contributions from noncontrolling interests	67	31
Distributions to noncontrolling interests	(19)	(24)
Disposition of businesses	0	(5)
Acquisition of treasury stock	0	0
Issuance and exercise of stock-based compensation benefit plans, net of income tax	0	0
Sale of subsidiary shares to noncontrolling interests	0	0
Ending Balance	$ 3,013	$ 3,448	$ 3,013