RECENT INVESTMENT ACTIVITY 2 (Details) - USD ($) $ in Millions		9 Months Ended
	Jul. 16, 2014	Sep. 30, 2015	Mar. 13, 2014
Energia Sierra Juarez wind project [Member]
Business Acquisition [Line Items]
Equity Method Investment Ownership Percentage	50.00%
Deconsolidation Gain Or Loss Amount After Tax	$ 14
Gain attributable to remeasurement, after tax	$ 7
Copper Mountain Solar 3 [Member]
Business Acquisition [Line Items]
Equity Method Investment Ownership Percentage			50.00%
California Solar Partnership [Member]
Business Acquisition [Line Items]
Equity Method Investment Ownership Percentage		50.00%
Equity Investment In Solar Projects		$ 109
Additional Equity investment in solar projects		12
Black Oak Getty Wind [Member]
Business Acquisition [Line Items]
Total business acquisition costs		$ 8
Ownership Percentage in consolidated entity		100.00%