- GENERAL RATE CASE (Details) - USD ($) $ in Millions		1 Months Ended	3 Months Ended
	Oct. 06, 2017	Apr. 30, 2018	Mar. 31, 2018
Southern California Gas Company [Member]
General Rate Case [Line Items]
GRC requested revenue requirement	$ 2,989
GRC requested revenue requirement adjustment	533
Tax Cuts and Jobs Act, Change in Tax Rate, Change in Revenue Requirement			$ 58
GRC revenue requirement			2,931
Southern California Gas Company [Member] | General Rate Case [Member]
General Rate Case [Line Items]
Tracked income tax expense liability			77
Southern California Gas Company [Member] | Future Refund of Rates to Customers [Member]
General Rate Case [Line Items]
Regulatory liability			19
San Diego Gas and Electric Company [Member]
General Rate Case [Line Items]
GRC requested revenue requirement	2,199
GRC requested revenue requirement adjustment	$ 217
Tax Cuts and Jobs Act, Change in Tax Rate, Change in Revenue Requirement			58
San Diego Gas and Electric Company [Member] | General Rate Case [Member]
General Rate Case [Line Items]
Tracked income tax expense liability			67
San Diego Gas and Electric Company [Member] | Future Refund of Rates to Customers [Member]
General Rate Case [Line Items]
Regulatory liability			18
San Diego Gas and Electric Company [Member] | Future Refund of Rates to Customers - FERC [Member]
General Rate Case [Line Items]
Regulatory liability			$ 15
Minimum [Member] | Southern California Gas Company [Member]
General Rate Case [Line Items]
GRC requested revenue requirement adjustment percentage	6.00%
Minimum [Member] | San Diego Gas and Electric Company [Member]
General Rate Case [Line Items]
GRC requested revenue requirement adjustment percentage	5.00%
Maximum [Member] | Southern California Gas Company [Member]
General Rate Case [Line Items]
GRC requested revenue requirement adjustment percentage	8.00%
Maximum [Member] | San Diego Gas and Electric Company [Member]
General Rate Case [Line Items]
GRC requested revenue requirement adjustment percentage	7.00%
Subsequent Event [Member] | Southern California Gas Company [Member]
General Rate Case [Line Items]
GRC requested revenue requirement		$ 2,695
GRC requested revenue requirement adjustment		239
Subsequent Event [Member] | San Diego Gas and Electric Company [Member]
General Rate Case [Line Items]
GRC requested revenue requirement		1,918
GRC requested revenue requirement adjustment		$ 64
Proposed annual attrition percentage		4.00%
Subsequent Event [Member] | Minimum [Member] | Southern California Gas Company [Member]
General Rate Case [Line Items]
Proposed annual attrition percentage		4.00%
Subsequent Event [Member] | Maximum [Member] | Southern California Gas Company [Member]
General Rate Case [Line Items]
Proposed annual attrition percentage		5.00%
Otay Mesa Energy Center [Member] | Subsequent Event [Member] | San Diego Gas and Electric Company [Member]
General Rate Case [Line Items]
Owning and operating costs		$ 68