RECENT INVESTMENT ACTIVITY (DETAILS) (USD $) In Millions, unless otherwise specified	1 Months Ended	3 Months Ended	6 Months Ended
	Feb. 28, 2013	Jun. 30, 2012 Willmut Gas [Member]	Jun. 30, 2012 Willmut Gas [Member]	May 20, 2012 Willmut Gas [Member]
Property, plant and equipment
Total liabilities				$ (10)
Pro forma revenues		1	7
Cash consideration (fair value of total consideration)				19
Proceeds from sale of Mesquite Power plant	371
Gain on sale of Mesquite Power plant	74
Gain on sale of Mesquite Power plant, after tax	$ 44