FAIR VALUE MEASUREMENTS 3 (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	$ 95	$ 58	$ 99	$ 61
Realized and unrealized gains (losses)	5	(2)	6	(3)
Allocated transmission instruments			1	0
Settlements	(15)	(9)	(21)	(11)
Balance at end of period	85	47	85	47
Change in unrealized gains (losses) relating to instruments still held at period end	0	(1)	0	(1)
CRR Auction Rate Per MWh, Minimum	(6)	(8)	(6)	(8)
CRR Auction Rate Per MWh, Maximum	$ 12	$ 8	$ 12	$ 8