Equity (Details) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended		36 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Jun. 30, 2013	Dec. 31, 2012
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance			$ 7,514	$ 9,729
Net income (loss)	223	(1,402)	755	(680)
Total foreign currency translation adjustment, net of income tax	(6)	(25)	(223)	(269)
Total change in derivative fair value, net of income tax	34	(28)	205	(14)
Total pension adjustments, net of income tax	12	6	39	19
Capital contributions from noncontrolling interests			86	12
Distributions to noncontrolling interests			(382)	(625)
Disposition of businesses			(20)	(37)
Acquisition of treasury stock			(63)	(301)
Issuance and exercise of stock-based compensation benefit plans, net of income tax			39	40
Dividends declared on common stock ($0.08 per share)			(60)	(30)
Sale of subsidiary shares to noncontrolling interests			83	0
Acquisition of subsidiary shares from noncontrolling interests			(7)	(8)
Ending Balance	7,966	7,836	7,966	7,836
Dividend
Dividends declared on common stock (per share amount)	$ 0	$ 0.04	$ 0.08	$ 0.04
Stock Repurchase Plan [Abstract]
Acquisition of treasury stock (shares)	3,738,142				64,012,231
Treasury Stock Value Acquired Cost Method Excluding Commissions	45				743
Treasury Stock Acquired Average Cost Per Share					$ 11.60
Stock Repurchase Program, Remaining Authorized Repurchase Amount			237
Treasury stock, shares (in shares)	70,832,607		70,832,607			66,415,984
Unrealized Derivative Losses [Roll Forward]
Unrealized derivative losses, beginning balance			(481)
Other comprehensive income before reclassifications			54
Amount reclassified from accumulated other comprehensive loss			97
Net current-period other comprehensive income			151
Unrealized Derivative Losses, ending balance	(330)		(330)
Unfunded PensionObligation [Roll Forward]
Unfunded pension obligation, beginning balance			(382)
Amount reclassified from accumulated other comprehensive loss			9
Net current-period other comprehensive income			9
Unfunded pension obligation, ending balance	(373)		(373)
Available For Sale Securities [Roll Forward] [Roll Forward]
Available for sale securities, beginning balance			0
Other comprehensive income before reclassification	0	1	(1)	1
Amounts reclassified from accumulated other comprehensive income	0	0	1	0
Net current-period other comprehensive income			0
Available for sale securities, ending balance	0		0
Foreign Currency Translation Adjustment [Roll Forward]
Foreign currency translation adjustment, beginning balance			(2,057)
Other comprehensive income before reclassification			(194)
Amounts reclassified from accumulated other comprehensive income			36
Net current-period other comprehensive income			(158)
Foreign currency translation adjustment, ending balance	(2,215)		(2,215)
Accumulated Other Comprehensive Income Loss Net Of Tax [Roll Forward]
Accumulated other comprehensive loss, beginning balance			(2,920)
Other comprehensive income before reclassifications			(141)
Amounts reclassified from accumulated other comprehensive loss			143
Net current-period other comprehensive income			2
Accumulated other comprehensive loss, ending balance	(2,918)		(2,918)
Parent [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance			4,569	5,946
Net income (loss)			320	(1,087)
Total foreign currency translation adjustment, net of income tax			(158)	(158)
Total change in derivative fair value, net of income tax			151	6
Total pension adjustments, net of income tax			9	5
Capital contributions from noncontrolling interests			0	0
Distributions to noncontrolling interests			0	0
Disposition of businesses			0	0
Acquisition of treasury stock			(63)	(301)
Issuance and exercise of stock-based compensation benefit plans, net of income tax			39	40
Dividends declared on common stock ($0.08 per share)			(60)	(30)
Sale of subsidiary shares to noncontrolling interests			12	0
Acquisition of subsidiary shares from noncontrolling interests			(6)	3
Ending Balance	4,813	4,424	4,813	4,424
Noncontrolling Interest [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance			2,945	3,783
Net income (loss)			435	407
Total foreign currency translation adjustment, net of income tax			(65)	(111)
Total change in derivative fair value, net of income tax			54	(20)
Total pension adjustments, net of income tax			30	14
Capital contributions from noncontrolling interests			86	12
Distributions to noncontrolling interests			(382)	(625)
Disposition of businesses			(20)	(37)
Acquisition of treasury stock			0	0
Issuance and exercise of stock-based compensation benefit plans, net of income tax			0	0
Dividends declared on common stock ($0.08 per share)			0	0
Sale of subsidiary shares to noncontrolling interests			71	0
Acquisition of subsidiary shares from noncontrolling interests			(1)	(11)
Ending Balance	$ 3,153	$ 3,412	$ 3,153	$ 3,412