OTHER FINANCIAL DATA - SHARE-BASED COMPENSATION (Details) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation expense, net of income taxes	$ 6	$ 5	$ 17	$ 18
Restricted Stock Awards Granted			4,617
Restricted stock units issued by IEnova			1,014,899
Performance-Based [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Restricted stock units granted			651,193
Service-Based [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Restricted stock units granted			105,680