OTHER FINANCIAL DATA - SHARE-BASED COMPENSATION (Details) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation expense, net of income taxes	$ 7	$ 6
Restricted stock units issued by IEnova	136,996
Performance-Based [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Restricted stock units granted	443,791
Service-Based [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Restricted stock units granted	77,492
Performance-Based, Total Shareholder Return [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Restricted stock units granted	355,278
Performance-Based, Earnings Per Share [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Restricted stock units granted	88,513