SIGNIFICANT ACCOUNTING POLICIES AND OTHER FINANCIAL DATA - ASSET RETIREMENT OBLIGATIONS (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Beginning Balance	$ 2,972	$ 2,876
Accretion expense	123	121
Liabilities incurred	2	7
Deconsolidation and reclassification	(2)	(61)
Payments	(46)	(42)
Revisions	34	71
Ending Balance	3,083	2,972
San Diego Gas and Electric Company [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Beginning Balance	874	839
Accretion expense	39	39
Liabilities incurred	0	0
Deconsolidation and reclassification	(2)	0
Payments	(44)	(39)
Revisions	(1)	35
Ending Balance	866	874
Southern California Gas Company [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Beginning Balance	2,063	1,953
Accretion expense	81	78
Liabilities incurred	0	0
Deconsolidation and reclassification	0	0
Payments	(2)	(3)
Revisions	35	35
Ending Balance	$ 2,177	2,063
Termoelectrica de Mexicali [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Reclassified from held for sale		5
Sempra Renewables [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Reclassified to held for sale		6
Sempra LNG [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Reclassified to held for sale		8
Sempra Renewables [Member] | Disposal Group Disposed of by Sale [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Deconsolidation and reclassification		$ 52