INVESTMENTS IN UNCONSOLIDATED ENTITIES - Narrative (Details) - USD ($) $ in Millions			1 Months Ended		3 Months Ended
	Apr. 23, 2018	Mar. 09, 2018	Apr. 30, 2018	Mar. 31, 2018	Mar. 31, 2018	Mar. 31, 2017		Dec. 31, 2017	[1]
Schedule of Equity Method Investments [Line Items]
Goodwill				$ 2,406	$ 2,406			$ 2,397
Equity earnings				15
Equitization of note receivable due from unconsolidated affiliate					0	$ 19	[2]
Maximum exposure under guarantor obligations				4,500	4,500
Aggregate carrying value of guarantor obligations				31	31
Joint Venture [Member] | Sempra South American Utilities [Member] | Eletrans [Member]
Schedule of Equity Method Investments [Line Items]
Equitization of note receivable due from unconsolidated affiliate						19
Joint Venture [Member] | Sempra Mexico [Member] | IMG [Member]
Schedule of Equity Method Investments [Line Items]
Investments made during period					25	46
Joint Venture [Member] | Sempra LNG & Midstream [Member] | Cameron LNG [Member]
Schedule of Equity Method Investments [Line Items]
Investments made during period					29	1
Capitalized interest					$ 11	$ 11
Oncor Holdings [Member]
Schedule of Equity Method Investments [Line Items]
Equity earnings				19
Oncor Electric Delivery Company LLC. [Member]
Schedule of Equity Method Investments [Line Items]
Acquired percentage interest		80.25%
Subsequent Event [Member] | Joint Venture [Member] | Sempra LNG & Midstream [Member] | Cameron LNG [Member]
Schedule of Equity Method Investments [Line Items]
Investments made during period			$ 32
Sempra Texas Holdings Corp [Member] | Oncor Holdings [Member]
Schedule of Equity Method Investments [Line Items]
Consideration		$ 9,161
Goodwill		$ 2,672
Sempra Texas Holdings Corp [Member] | Oncor Holdings [Member] | Sempra Texas Intermediate Holding Company LLC [Member]
Schedule of Equity Method Investments [Line Items]
Ownership percentage in consolidated entity		100.00%
Sempra Texas Holdings Corp [Member] | Oncor Electric Delivery Company LLC. [Member]
Schedule of Equity Method Investments [Line Items]
Acquired percentage interest		80.03%
Sempra Texas Holdings Corp [Member] | Oncor Electric Delivery Company LLC. [Member] | Oncor Holdings [Member]
Schedule of Equity Method Investments [Line Items]
Ownership percentage in consolidated entity		80.25%
Oncor Electric Delivery Company LLC. [Member]
Schedule of Equity Method Investments [Line Items]
Equity earnings				$ 15
Oncor Electric Delivery Company LLC. [Member] | Subsequent Event [Member]
Schedule of Equity Method Investments [Line Items]
Investments made during period	$ 117

[1] Derived from audited financial statements.

[2] As adjusted for the retrospective adoption of ASU 2016-18, which we discuss in Note 2.