GENERAL INFORMATION AND OTHER FINANCIAL DATA - VARIABLE INTEREST ENTITIES (Details)		1 Months Ended	3 Months Ended			6 Months Ended
	Mar. 09, 2018	Jun. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)		Jun. 30, 2018 USD ($) MW	Jun. 30, 2017 USD ($)		Dec. 31, 2017 USD ($)
Variable Interest Entities [Line Items]
Equity method investment		$ 9,407,000,000	$ 9,407,000,000			$ 9,407,000,000			$ 0	[1]
Property, plant and equipment, net		34,916,000,000	34,916,000,000			34,916,000,000			36,503,000,000	[1]
Other noncontrolling interests		2,518,000,000	2,518,000,000			2,518,000,000			2,450,000,000	[1]
Energy-related businesses			374,000,000	$ 336,000,000	[2]	738,000,000	$ 669,000,000	[2]
Operation and maintenance			(783,000,000)	(748,000,000)	[2]	(1,564,000,000)	(1,467,000,000)	[2]
Depreciation and amortization			(392,000,000)	(368,000,000)	[2]	(778,000,000)	(728,000,000)	[2],[3]
Interest expense			(237,000,000)	(159,000,000)	[2]	(453,000,000)	(328,000,000)	[2]
Income before income taxes			(1,109,000,000)	397,000,000	[2]	(442,000,000)	1,149,000,000	[2]
Income tax expense			583,000,000	(167,000,000)	[2]	294,000,000	(462,000,000)	[2]
Income (loss) before income taxes/Net income (loss)			(530,000,000)	248,000,000	[2]	(172,000,000)	700,000,000	[2],[3]
(Earnings) losses attributable to noncontrolling interest			(5,000,000)	12,000,000	[2]	12,000,000	1,000,000	[2]
Earnings attributable to common shares			(561,000,000)	259,000,000		(214,000,000)	700,000,000
Otay Mesa VIE [Member]
Variable Interest Entities [Line Items]
Property, plant and equipment, net		310,000,000	310,000,000			310,000,000			321,000,000
Sempra Renewables [Member] | Tax Equity Investors [Member]
Variable Interest Entities [Line Items]
Property, plant and equipment, net									1,412,000,000
Equity		669,000,000	669,000,000			669,000,000			631,000,000
Energy-related businesses			32,000,000	18,000,000		49,000,000	31,000,000
Operation and maintenance			(4,000,000)	(7,000,000)		(8,000,000)	(9,000,000)
Depreciation and amortization			(12,000,000)	(8,000,000)		(23,000,000)	(16,000,000)
Income before income taxes			16,000,000	3,000,000		18,000,000	6,000,000
Income tax expense			(7,000,000)	(4,000,000)		(12,000,000)	(6,000,000)
Income (loss) before income taxes/Net income (loss)			9,000,000	(1,000,000)		6,000,000	0
(Earnings) losses attributable to noncontrolling interest			20,000,000	7,000,000		41,000,000	10,000,000
Earnings attributable to common shares			29,000,000	6,000,000		47,000,000	10,000,000
Sempra Natural Gas [Member] | Cameron LNG Holdings [Member]
Variable Interest Entities [Line Items]
Equity method investment		1,182,000,000	1,182,000,000			1,182,000,000			997,000,000
Sempra Texas Utility [Member] | Oncor Holdings [Member]
Variable Interest Entities [Line Items]
Equity method investment		9,407,000,000	9,407,000,000			9,407,000,000
San Diego Gas and Electric Company [Member]
Variable Interest Entities [Line Items]
Property, plant and equipment, net		15,310,000,000	15,310,000,000			15,310,000,000			14,838,000,000	[1]
Other noncontrolling interests		29,000,000	29,000,000			29,000,000			28,000,000	[1]
Operation and maintenance			251,000,000	241,000,000	[2]	499,000,000	472,000,000	[2]
Depreciation and amortization			169,000,000	166,000,000	[3]	335,000,000	329,000,000	[2]
Operating income			215,000,000	237,000,000	[2]	463,000,000	511,000,000	[2]
Interest expense			(53,000,000)	(49,000,000)	[2]	(105,000,000)	(98,000,000)	[2]
Income before income taxes			188,000,000	207,000,000	[2]	413,000,000	454,000,000	[2]
Income tax expense			(42,000,000)	(54,000,000)	[2]	(98,000,000)	(144,000,000)	[2]
Income (loss) before income taxes/Net income (loss)			146,000,000	153,000,000	[2]	315,000,000	310,000,000	[2]
(Earnings) losses attributable to noncontrolling interest			0	(4,000,000)	[2]	$ 1,000,000	(6,000,000)	[2]
San Diego Gas and Electric Company [Member] | Otay Mesa VIE [Member]
Variable Interest Entities [Line Items]
Generating capacity | MW						605
Conditional purchase obligation		280,000,000	280,000,000			$ 280,000,000
Equity of variable interest entity		29,000,000	29,000,000			29,000,000			28,000,000
Secured debt of variable interest entity		290,000,000	290,000,000			290,000,000
Property, plant and equipment, net		310,000,000	310,000,000			310,000,000			$ 321,000,000
Cost of electric fuel and purchased power			(16,000,000)	(21,000,000)		(32,000,000)	(39,000,000)
Operation and maintenance			4,000,000	5,000,000		8,000,000	9,000,000
Depreciation and amortization			7,000,000	7,000,000		15,000,000	14,000,000
Total operating expenses			(5,000,000)	(9,000,000)		(9,000,000)	(16,000,000)
Operating income			5,000,000	9,000,000		9,000,000	16,000,000
Interest expense			(5,000,000)	(5,000,000)		(10,000,000)	(10,000,000)
Income (loss) before income taxes/Net income (loss)			0	4,000,000		(1,000,000)	6,000,000
(Earnings) losses attributable to noncontrolling interest			0	(4,000,000)		1,000,000	(6,000,000)
Earnings attributable to common shares			$ 0	$ 0		$ 0	$ 0
Oncor Holdings [Member] | Sempra Texas Holdings Corp [Member] | Sempra Texas Intermediate Holding Company LLC [Member]
Variable Interest Entities [Line Items]
Ownership percentage in consolidated entity	100.00%
Oncor Electric Delivery Company LLC. [Member]
Variable Interest Entities [Line Items]
Acquired percentage interest	80.25%
Oncor Electric Delivery Company LLC. [Member] | Sempra Texas Holdings Corp [Member]
Variable Interest Entities [Line Items]
Acquired percentage interest	80.03%
Property, Plant and Equipment, Net [Member] | Sempra Renewables [Member] | Tax Equity Investors [Member]
Variable Interest Entities [Line Items]
Assets reclassified to held-for-sale		$ 1,423,000,000

[1] Derived from audited financial statements.

[2] 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.

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