REVENUES - CONTRACT LIABILITIES (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Contract with Customer, Liability [Roll Forward]
Contract liabilities, opening balance	$ (163)	$ (70)
Revenue from performance obligations satisfied during reporting period	3	1
Payments received in advance		(95)
Contract liabilities, closing balance	(160)	(164)
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	(156)
San Diego Gas and Electric Company [Member]
Contract with Customer, Liability [Roll Forward]
Contract liabilities, opening balance	(91)	0
Revenue from performance obligations satisfied during reporting period	3	0
Payments received in advance		(92)
Contract liabilities, closing balance	(88)	$ (92)
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	$ (84)