SIGNIFICANT ACCOUNTING POLICIES AND OTHER FINANCIAL DATA - REVENUES (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenues Disclosure [Abstract]
Electric revenues	$ 5,415	$ 5,211	$ 5,158
Natural gas revenues	4,361	4,050	4,096
Total Utilities Revenues at Sempra Energy Consolidated	$ 9,776	$ 9,261	$ 9,254