REVENUES - CONTRACT LIABILITIES (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Contract with Customer, Liability [Roll Forward]
Contract liabilities, opening balance	$ (163)	$ (70)
Revenue from performance obligations satisfied during reporting period	1	1
Payments received in advance		(2)
Contract liabilities, closing balance	(162)	$ (71)
Other Current Liabilities [Member]
Contract with Customer, Liability [Roll Forward]
Contract liabilities, closing balance	(4)
Deferred Credits and Other [Member]
Contract with Customer, Liability [Roll Forward]
Contract liabilities, closing balance	(158)
San Diego Gas and Electric Company [Member]
Contract with Customer, Liability [Roll Forward]
Contract liabilities, opening balance	(91)
Revenue from performance obligations satisfied during reporting period	1
Contract liabilities, closing balance	(90)
San Diego Gas and Electric Company [Member] | Other Current Liabilities [Member]
Contract with Customer, Liability [Roll Forward]
Contract liabilities, closing balance	(4)
San Diego Gas and Electric Company [Member] | Deferred Credits and Other [Member]
Contract with Customer, Liability [Roll Forward]
Contract liabilities, closing balance	$ (86)