SIGNIFICANT ACCOUNTING POLICIES AND OTHER FINANCIAL DATA - INVENTORIES (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Inventory [Line Items]
Natural gas	$ 95	$ 109
LNG	4	11
Materials and supplies	197	187
Inventories	296	307
SDG&E [Member]
Inventory [Line Items]
Natural gas	0	4
LNG	0	0
Materials and supplies	102	101
Inventories	102	105
SoCalGas [Member]
Inventory [Line Items]
Natural gas	92	75
LNG	0	0
Materials and supplies	42	49
Inventories	134	124
Sempra South American Utilities [Member]
Inventory [Line Items]
Natural gas	0	0
LNG	0	0
Materials and supplies	38	30
Inventories	38	30
Sempra Mexico [Member]
Inventory [Line Items]
Natural gas	0	0
LNG	4	7
Materials and supplies	15	2
Inventories	19	9
Sempra Renewables [Member]
Inventory [Line Items]
Natural gas	0	0
LNG	0	0
Materials and supplies	0	5
Inventories	0	5
Sempra LNG & Midstream [Member]
Inventory [Line Items]
Natural gas	3	30
LNG	0	4
Materials and supplies	0	0
Inventories	$ 3	$ 34