GENERAL INFORMATION AND OTHER FINANCIAL DATA - INVENTORIES (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Inventory [Line Items]
Natural gas	$ 21	$ 95
LNG	7	4
Materials and supplies	161	159
Inventory	189	258	[1]
SDG&E [Member]
Inventory [Line Items]
Natural gas	0	0
LNG	0	0
Materials and supplies	99	102
Inventory	99	102
SoCalGas [Member]
Inventory [Line Items]
Natural gas	12	92
LNG	0	0
Materials and supplies	46	42
Inventory	58	134
Sempra Mexico [Member]
Inventory [Line Items]
Natural gas	0	0
LNG	7	4
Materials and supplies	16	15
Inventory	23	19
Sempra LNG [Member]
Inventory [Line Items]
Natural gas	9	3
LNG	0	0
Materials and supplies	0	0
Inventory	$ 9	$ 3

[1] Derived from audited financial statements.