CALIFORNIA UTILITIES' REGULATORY MATTERS - SCHEDULE OF GENERAL RATE CASE (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended	12 Months Ended
	Jun. 30, 2016	Jun. 30, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
San Diego Gas and Electric Company [Member] | Year 2016 [Member]
Public Utilities General Disclosures [Line Items]
General Rate Case, Revenue Requirement					$ 1,791
General Rate Case, Revenue Requirement, Revised Request					1,811
General Rate Case, Revenue Requirement Increase (Decrease), Revised Request					(20)
General Rate Case, Revenue Requirement Percentage Annual Escalation			3.50%	3.50%
General Rate Case, Rate Base Adjustment					(55)
General Rate Case, Revenue Requirement Adjustment Due To Rate Base Adjustment					(7)
General Rate Case, Regulatory Asset Due To Retroactive Revenue	$ 23	$ 23
General Rate Case, Regulatory Asset Due To Retroactive Revenue, Noncurrent	8	8
General Rate Case, Deductible Per Event	5	5
General Rate Case, Regulatory Liability	15	15
San Diego Gas and Electric Company [Member] | Pre Tax [Member]
Rate Case Impacts [Line Items]
General Rate Case, Retroactive Revenue Requirement Increase From 2016 GRC	15
General Rate Case, Adjustment To Revenue, Refund Of 2015 Tax Memorandum Account	(37)
General Rate Case, Adjustment To Revenue, True Up Of 2012-2014 Tax Estimates	(15)
General Rate Case, Total Adjustments To Revenue Related To Tax Repairs Deductions	(52)
San Diego Gas and Electric Company [Member] | After Tax [Member]
Rate Case Impacts [Line Items]
General Rate Case, Retroactive Revenue Requirement Increase From 2016 GRC	9
General Rate Case, Adjustment To Revenue, Refund Of 2015 Tax Memorandum Account	(22)
General Rate Case, Adjustment To Revenue, True Up Of 2012-2014 Tax Estimates	(9)
General Rate Case, Total Adjustments To Revenue Related To Tax Repairs Deductions	(31)
Southern California Gas Company [Member] | Year 2016 [Member]
Public Utilities General Disclosures [Line Items]
General Rate Case, Revenue Requirement					2,204
General Rate Case, Revenue Requirement, Revised Request					2,219
General Rate Case, Revenue Requirement Increase (Decrease), Revised Request					(15)
General Rate Case, Revenue Requirement Percentage Annual Escalation			3.50%	3.50%
General Rate Case, Rate Base Adjustment					(38)
General Rate Case, Revenue Requirement Adjustment Due To Rate Base Adjustment					$ (5)
General Rate Case, Regulatory Asset Due To Retroactive Revenue	60	60
General Rate Case, Regulatory Asset Due To Retroactive Revenue, Noncurrent	21	21
General Rate Case, Deductible Per Event	5	5
General Rate Case, Regulatory Liability	11	11
Southern California Gas Company [Member] | Pre Tax [Member]
Rate Case Impacts [Line Items]
General Rate Case, Earnings Charge Due To Income Tax Forecasted Incurred	15	15
General Rate Case, Retroactive Revenue Requirement Increase From 2016 GRC	20
General Rate Case, Adjustment To Revenue, Refund Of 2015 Tax Memorandum Account	(72)
General Rate Case, Adjustment To Revenue, True Up Of 2012-2014 Tax Estimates	(11)
General Rate Case, Total Adjustments To Revenue Related To Tax Repairs Deductions	(83)
Southern California Gas Company [Member] | After Tax [Member]
Rate Case Impacts [Line Items]
General Rate Case, Earnings Charge Due To Income Tax Forecasted Incurred	9	$ 9
General Rate Case, Retroactive Revenue Requirement Increase From 2016 GRC	12
General Rate Case, Adjustment To Revenue, Refund Of 2015 Tax Memorandum Account	(43)
General Rate Case, Adjustment To Revenue, True Up Of 2012-2014 Tax Estimates	(6)
General Rate Case, Total Adjustments To Revenue Related To Tax Repairs Deductions	$ (49)