REVENUES - CONTRACT LIABILITIES (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Contract with Customer, Liability [Roll Forward]
Contract liabilities, opening balance	$ (70)	$ 0
Adoption of ASC 606 adjustment		(61)
Revenue from performance obligations satisfied during reporting period	1	5
Payments received in advance	(2)	(7)
Contract liabilities, closing balance	(71)	(63)
Other Current Liabilities [Member]
Contract with Customer, Liability [Roll Forward]
Contract liabilities, closing balance	0
Deferred Credits and Other [Member]
Contract with Customer, Liability [Roll Forward]
Contract liabilities, closing balance	(71)
San Diego Gas and Electric Company [Member]
Contract with Customer, Liability [Roll Forward]
Contract liabilities, closing balance	0	0
Southern California Gas Company [Member]
Contract with Customer, Liability [Roll Forward]
Contract liabilities, closing balance	$ 0	$ 0