INVESTMENTS IN UNCONSOLIDATED ENTITIES (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Schedule of Equity Method Investments [Line Items]
Equity method investment	$ 2,517	$ 2,080
Income (Loss) from Equity Method Investments	34	6	$ 104
Cameron LNG Holdings [Member]
Schedule of Equity Method Investments [Line Items]
Difference between carrying amount of equity method investment and underlying equity	237	190
R B S Sempra Commodities [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investment	67
Other Equity Method Investments [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investment	10	17
Income (loss) from equity method investment earnings (losses) net of tax	42	78	85
Other Equity Method Investments And Other Investments [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investment	2,527	2,097
Sempra Renewables [Member] | California Solar Partnership [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investment	107	113
Income (Loss) from Equity Method Investments	7	7	6
Sempra Renewables [Member] | Copper Mountain Solar 3 [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investment	44	42
Income (Loss) from Equity Method Investments	8	8	8
Sempra Renewables [Member] | Broken Bow 2 Wind [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investment	32	35
Income (Loss) from Equity Method Investments	(2)	(2)	(2)
Sempra Renewables [Member] | Cedar Creek 2 Wind Farm [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investment	72	75
Income (Loss) from Equity Method Investments	(2)	(2)	(6)
Sempra Renewables [Member] | Flat Ridge 2 Wind Farm [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investment	255	271
Income (Loss) from Equity Method Investments	(13)	(7)	(12)
Sempra Renewables [Member] | Fowler Ridge 2 Wind Farm [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investment	44	43
Income (Loss) from Equity Method Investments	4	4	4
Sempra Renewables [Member] | Mehoopany Wind Farm [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investment	89	92
Income (Loss) from Equity Method Investments	(1)	0	(1)
Sempra Renewables [Member] | Copper Mountain Solar 2 [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investment	35	33
Income (Loss) from Equity Method Investments	5	6	7
Sempra Renewables [Member] | Mesquite Solar 1 [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investment	81	86
Income (Loss) from Equity Method Investments	18	17	16
Sempra Renewables [Member] | Auwahi Wind [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investment	42	41
Income (Loss) from Equity Method Investments	5	4	4
Sempra Renewables [Member] | Other Equity Method Investments [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investment	12	13
Income (Loss) from Equity Method Investments	0	(1)	0
Sempra LNG & Midstream [Member] | Cameron LNG Holdings [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investment	997	997
Income (Loss) from Equity Method Investments	5	(2)	5
Sempra LNG & Midstream [Member] | Rockies Express [Member]
Schedule of Equity Method Investments [Line Items]
Income (Loss) from Equity Method Investments	0	(26)	79
Sempra Energy and Other [Member] | R B S Sempra Commodities [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investment	67	67
Income (Loss) from Equity Method Investments	0	0	(4)
Sempra South American Utilities [Member] | Eletrans [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investment	16	(8)
Income (loss) from equity method investment earnings (losses) net of tax	4	3	(4)
Sempra Mexico [Member] | Ductos Energéticos del Norte [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investment	0	42
Income (loss) from equity method investment earnings (losses) net of tax	(13)	5	0
Sempra Mexico [Member] | Energia Sierra Juarez Wind Project [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investment	39	38
Difference between carrying amount of equity method investment and underlying equity				$ 12
Income (loss) from equity method investment earnings (losses) net of tax	0	6	6
Sempra Mexico [Member] | IEnova Pipelines [Member]
Schedule of Equity Method Investments [Line Items]
Income (loss) from equity method investment earnings (losses) net of tax	0	64	83
Sempra Mexico [Member] | IMG [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investment	221	100
Difference between carrying amount of equity method investment and underlying equity	5
Income (loss) from equity method investment earnings (losses) net of tax	45	0	0
Sempra Mexico [Member] | TAG [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investment	364	0
Difference between carrying amount of equity method investment and underlying equity	130
Income (loss) from equity method investment earnings (losses) net of tax	$ 6	$ 0	$ 0