Equity (Details) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended		6 Months Ended		60 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance				$ 7,325	$ 7,651
Net income		$ 264	$ 275	518	341
Total foreign currency translation adjustment, net of income tax		77	(29)	(344)	(18)
Total change in derivative fair value, net of income tax		89	(92)	29	(193)
Total pension adjustments, net of income tax		4	25	9	31
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets		(5)	0	(5)	0	$ (5)
Capital contributions from noncontrolling interests				97	113
Distributions to noncontrolling interests				(119)	(215)
Noncontrolling Interest, Increase from Business Combination	[1]			16	0
Disposition of businesses				0	(151)
Acquisition of treasury stock		(271)		(307)	(32)	(1,600)
Issuance and exercise of stock-based compensation benefit plans, net of income tax				17	16
Dividends declared on common stock				(70)	(36)
Sale of subsidiary shares to noncontrolling interests				(82)	0
noncontrolling interest, increase from transaction between entities under common control				0	7
Acquisition of subsidiary shares from noncontrolling interests				0	(6)
Ending Balance		$ 7,084	$ 7,508	$ 7,084	$ 7,508	7,084
Common Stock, Dividends, Per Share, Declared		$ 0.10	$ 0.05	$ 0.10	$ 0.05
Common Stock, Dividends, Per Share, Cash Paid				$ 0.10
Parent [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance				$ 4,272	$ 4,330
Net income				211	75
Total foreign currency translation adjustment, net of income tax				(204)	(56)
Total change in derivative fair value, net of income tax				30	(99)
Total pension adjustments, net of income tax				2	14
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets		$ (5)	$ 0	(5)	0	(5)
Capital contributions from noncontrolling interests				0	0
Distributions to noncontrolling interests				0	0
Noncontrolling Interest, Increase from Business Combination	[1]			0	0
Disposition of businesses				0	0
Acquisition of treasury stock				(307)	(32)
Issuance and exercise of stock-based compensation benefit plans, net of income tax				17	16
Dividends declared on common stock				(70)	(36)
Sale of subsidiary shares to noncontrolling interests				(82)	0
noncontrolling interest, increase from transaction between entities under common control				0	5
Acquisition of subsidiary shares from noncontrolling interests				0	(6)
Ending Balance		3,864	4,211	3,864	4,211	3,864
Noncontrolling Interest [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance				3,053	3,321
Net income				307	266
Total foreign currency translation adjustment, net of income tax				(140)	38
Total change in derivative fair value, net of income tax				(1)	(94)
Total pension adjustments, net of income tax				7	17
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets		0	0	0	0	0
Capital contributions from noncontrolling interests				97	113
Distributions to noncontrolling interests				(119)	(215)
Noncontrolling Interest, Increase from Business Combination	[1]			16	0
Disposition of businesses				0	(151)
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	0
Sale of subsidiary shares to noncontrolling interests				0	0
noncontrolling interest, increase from transaction between entities under common control				0	2
Acquisition of subsidiary shares from noncontrolling interests				0	0
Ending Balance		$ 3,220	$ 3,297	$ 3,220	$ 3,297	$ 3,220

[1] (1) Fair value of a tax equity partner’s right to preferential returns as a result of the acquisition of Solar Power PR, LLC (Solar Puerto Rico), which was previously accounted for as an equity method investment.