GENERAL INFORMATION AND OTHER FINANCIAL DATA - INVENTORIES (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Inventory [Line Items]
Natural gas	$ 55	$ 110
LNG	5	9
Materials and supplies	157	158
Inventory	217	277	[1]
San Diego Gas and Electric Company [Member]
Inventory [Line Items]
Natural gas	1	1
LNG	0	0
Materials and supplies	92	93
Inventory	93	94	[1]
Southern California Gas Company [Member]
Inventory [Line Items]
Natural gas	32	90
LNG	0	0
Materials and supplies	47	46
Inventory	$ 79	$ 136	[1]

[1] Derived from audited financial statements.