INVESTMENTS IN UNCONSOLIDATED ENTITIES - SUMMARY OF INVESTMENTS (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2018	Dec. 31, 2017		Dec. 31, 2016
Schedule of Equity Method Investments [Line Items]
Equity method investment		$ 9,652	$ 0
Other investments		2,337	2,527
Goodwill		2,373	2,397		$ 2,364
Equity earnings, before income tax		(236)	34		6
Equity earnings (losses), net of tax		412	42		78
Total equity earnings		176	76	[1]	84	[1]
Cameron LNG Holdings [Member]
Schedule of Equity Method Investments [Line Items]
Difference between carrying amount of equity method investment and underlying equity		284	237
R B S Sempra Commodities [Member]
Schedule of Equity Method Investments [Line Items]
Other than temporary impairment	$ 65
Other Equity Method Investments [Member]
Schedule of Equity Method Investments [Line Items]
Other investments		2,326	2,517
Other Equity Method Investments [Member]
Schedule of Equity Method Investments [Line Items]
Other investments		$ 11	$ 10
Sempra Texas Intermediate Holding Company LLC [Member] | Oncor Holdings Electric Delivery Company LLC [Member]
Schedule of Equity Method Investments [Line Items]
Ownership percentage in equity method investee		100.00%	0.00%
Equity method investment		$ 9,652	$ 0
Difference between carrying amount of equity method investment and underlying equity		2,814
Equity method investment, difference between carrying amount and underlying equity, aoci		69
Equity method investment, difference between carrying amount and underlying equity, tax sharing liability		123
Equity earnings (losses), net of tax		$ 371	$ 0		0
Sempra South American Utilities [Member] | Eletrans [Member]
Schedule of Equity Method Investments [Line Items]
Ownership percentage in equity method investee		50.00%	50.00%
Other investments		$ 17	$ 16
Equity earnings (losses), net of tax		$ 1	$ 4		3
Sempra Renewables [Member] | California Solar Partnership [Member]
Schedule of Equity Method Investments [Line Items]
Ownership percentage in equity method investee		0.00%	50.00%
Other investments		$ 0	$ 107
Equity earnings, before income tax		$ 8	$ 7		7
Sempra Renewables [Member] | Copper Mountain Solar 3 [Member]
Schedule of Equity Method Investments [Line Items]
Ownership percentage in equity method investee		0.00%	50.00%
Other investments		$ 0	$ 44
Equity earnings, before income tax		$ 8	$ 8		8
Sempra Renewables [Member] | Broken Bow 2 Wind [Member]
Schedule of Equity Method Investments [Line Items]
Ownership percentage in equity method investee		0.00%	50.00%
Other investments		$ 0	$ 32
Equity earnings, before income tax		$ (2)	$ (2)		(2)
Sempra Renewables [Member] | Cedar Creek 2 Wind Farm [Member]
Schedule of Equity Method Investments [Line Items]
Ownership percentage in equity method investee		50.00%	50.00%
Other investments		$ 69	$ 72
Equity earnings, before income tax		$ (1)	$ (2)		(2)
Sempra Renewables [Member] | Flat Ridge 2 Wind Farm [Member]
Schedule of Equity Method Investments [Line Items]
Ownership percentage in equity method investee		50.00%	50.00%
Other investments		$ 82	$ 255
Other than temporary impairment in investment		169
Equity earnings, before income tax		$ (178)	$ (13)		(7)
Sempra Renewables [Member] | Fowler Ridge 2 Wind Farm [Member]
Schedule of Equity Method Investments [Line Items]
Ownership percentage in equity method investee		50.00%	50.00%
Other investments		$ 45	$ 44
Equity earnings, before income tax		$ 3	$ 4		4
Sempra Renewables [Member] | Mehoopany Wind Farm [Member]
Schedule of Equity Method Investments [Line Items]
Ownership percentage in equity method investee		50.00%	50.00%
Other investments		$ 57	$ 89
Other than temporary impairment in investment		31
Equity earnings, before income tax		$ (30)	$ (1)		0
Sempra Renewables [Member] | Copper Mountain Solar 2 [Member]
Schedule of Equity Method Investments [Line Items]
Ownership percentage in equity method investee		0.00%	50.00%
Other investments		$ 0	$ 35
Equity earnings, before income tax		$ 5	$ 5		6
Sempra Renewables [Member] | Mesquite Solar 1 [Member]
Schedule of Equity Method Investments [Line Items]
Ownership percentage in equity method investee		0.00%	50.00%
Other investments		$ 0	$ 81
Equity earnings, before income tax		$ 18	$ 18		17
Sempra Renewables [Member] | Auwahi Wind [Member]
Schedule of Equity Method Investments [Line Items]
Ownership percentage in equity method investee		50.00%	50.00%
Other investments		$ 38	$ 42
Equity earnings, before income tax		3	5		4
Sempra Renewables [Member] | Other Equity Method Investments [Member]
Schedule of Equity Method Investments [Line Items]
Other investments		0	12
Equity earnings, before income tax		$ (3)	$ 0		(1)
Sempra LNG & Midstream [Member] | Cameron LNG Holdings [Member]
Schedule of Equity Method Investments [Line Items]
Ownership percentage in equity method investee		50.20%	50.20%
Other investments		$ 1,271	$ 997
Equity earnings, before income tax		0	5		(2)
Sempra LNG & Midstream [Member] | Rockies Express [Member]
Schedule of Equity Method Investments [Line Items]
Equity earnings, before income tax		$ 0	$ 0		(26)
Sempra Energy and Other [Member] | R B S Sempra Commodities [Member]
Schedule of Equity Method Investments [Line Items]
Ownership percentage in equity method investee		49.00%	49.00%
Other investments		$ 0	$ 67
Equity earnings, before income tax		(67)	0		0
Sempra Mexico [Member] | Ductos Energéticos del Norte [Member]
Schedule of Equity Method Investments [Line Items]
Equity earnings (losses), net of tax		$ 0	$ (13)		5
Sempra Mexico [Member] | Energia Sierra Juarez Wind Project [Member]
Schedule of Equity Method Investments [Line Items]
Ownership percentage in equity method investee		50.00%	50.00%
Other investments		$ 43	$ 39
Difference between carrying amount of equity method investment and underlying equity		12
Equity earnings (losses), net of tax		2	0		6
Sempra Mexico [Member] | IEnova Pipelines [Member]
Schedule of Equity Method Investments [Line Items]
Equity earnings (losses), net of tax		$ 0	$ 0		64
Sempra Mexico [Member] | IMG [Member]
Schedule of Equity Method Investments [Line Items]
Ownership percentage in equity method investee		40.00%	40.00%
Other investments		$ 328	$ 221
Difference between carrying amount of equity method investment and underlying equity		5
Equity earnings (losses), net of tax		$ 29	$ 45		0
Sempra Mexico [Member] | TAG [Member]
Schedule of Equity Method Investments [Line Items]
Ownership percentage in equity method investee		50.00%	50.00%
Other investments		$ 376	$ 364
Difference between carrying amount of equity method investment and underlying equity		130
Equity earnings (losses), net of tax		9	$ 6		$ 0
Sempra Texas Holdings Corp [Member] | Oncor Holdings Electric Delivery Company LLC [Member]
Schedule of Equity Method Investments [Line Items]
Goodwill		$ 2,868

[1] As adjusted for the retrospective adoption of ASU 2017-07, which we discuss in Note 2, and a reclassification to conform to current year presentation, which we discuss in Note 1.