GENERAL INFORMATION AND OTHER FINANCIAL DATA - VARIABLE INTEREST ENTITIES (Details)			3 Months Ended		9 Months Ended
	Aug. 23, 2019 USD ($)	Mar. 09, 2018	Sep. 30, 2019 USD ($)	Sep. 30, 2018 USD ($)	Sep. 30, 2019 USD ($) MW	Sep. 30, 2018 USD ($)	Dec. 31, 2018 USD ($)
Variable Interest Entities [Line Items]
Cash and cash equivalents			$ 106,000,000		$ 106,000,000		$ 102,000,000	[1]
Inventories			270,000,000		270,000,000		258,000,000	[1]
Total current assets			3,666,000,000		3,666,000,000		3,645,000,000	[1]
Property, plant and equipment, net			35,520,000,000		35,520,000,000		34,439,000,000	[1]
Other noncurrent assets			850,000,000		850,000,000		962,000,000	[1]
Total assets			64,585,000,000		64,585,000,000		60,638,000,000	[1]
Other			914,000,000		914,000,000		935,000,000	[1]
Total current liabilities			9,498,000,000		9,498,000,000		7,523,000,000	[1]
Deferred credits and other			2,049,000,000		2,049,000,000		1,493,000,000	[1]
Other noncontrolling interests			1,911,000,000		1,911,000,000		2,090,000,000	[1]
Total liabilities and equity			64,585,000,000		64,585,000,000		60,638,000,000	[1]
Energy-related businesses			360,000,000	$ 463,000,000	1,078,000,000	$ 1,164,000,000
Interest expense			(279,000,000)	(222,000,000)	(797,000,000)	(656,000,000)
Operation and maintenance			(845,000,000)	(792,000,000)	(2,515,000,000)	(2,275,000,000)
Depreciation and amortization			(402,000,000)	(366,000,000)	(1,174,000,000)	(1,115,000,000)
Income (loss) from continuing operations before income taxes and equity earnings			448,000,000	345,000,000	1,235,000,000	(245,000,000)
Income tax expense			(61,000,000)	(139,000,000)	(150,000,000)	221,000,000
Net income			909,000,000	334,000,000	1,862,000,000	162,000,000
Earnings attributable to noncontrolling interests			(60,000,000)	(24,000,000)	(146,000,000)	(12,000,000)
Equity method investment			11,145,000,000		11,145,000,000		9,652,000,000	[1]
Variable Interest Entity, Primary Beneficiary
Variable Interest Entities [Line Items]
Assets of VIEs			779,000,000		779,000,000		286,000,000
Sempra Texas Utilities [Member] | Oncor Holdings [Member]
Variable Interest Entities [Line Items]
Equity method investment			11,145,000,000		11,145,000,000		9,652,000,000
Sempra Renewables [Member] | Tax Equity Investors [Member]
Variable Interest Entities [Line Items]
Energy-related businesses				28,000,000	8,000,000	77,000,000
Operation and maintenance				(5,000,000)	(2,000,000)	(13,000,000)
Depreciation and amortization				(13,000,000)	(4,000,000)	(36,000,000)
Income (loss) from continuing operations before income taxes and equity earnings				10,000,000	2,000,000	28,000,000
Income tax expense				(4,000,000)	0	(16,000,000)
Net income				6,000,000	2,000,000	12,000,000
Earnings attributable to noncontrolling interests				9,000,000	(1,000,000)	50,000,000
Earnings attributable to common shares				15,000,000	1,000,000	62,000,000
Equity							158,000,000
Sempra Natural Gas [Member] | Cameron LNG Holdings [Member]
Variable Interest Entities [Line Items]
Equity method investment			1,216,000,000		1,216,000,000		1,271,000,000
San Diego Gas and Electric Company [Member]
Variable Interest Entities [Line Items]
Cash and cash equivalents			24,000,000		24,000,000		8,000,000	[1]
Inventories			92,000,000		92,000,000		102,000,000	[1]
Total current assets			1,066,000,000		1,066,000,000		894,000,000	[1]
Property, plant and equipment, net			16,611,000,000		16,611,000,000		16,310,000,000	[1]
Other noncurrent assets			390,000,000		390,000,000		420,000,000	[1]
Total assets			20,336,000,000		20,336,000,000		19,225,000,000	[1]
Accounts payable			444,000,000		444,000,000		439,000,000	[1]
Other			268,000,000		268,000,000		141,000,000	[1]
Total current liabilities			1,245,000,000		1,245,000,000		1,428,000,000	[1]
Deferred credits and other			686,000,000		686,000,000		488,000,000	[1]
Other noncontrolling interests			0		0		100,000,000	[1]
Total liabilities and equity			20,336,000,000		20,336,000,000		19,225,000,000	[1]
Operation and maintenance			295,000,000	262,000,000	857,000,000	761,000,000
Depreciation and amortization			196,000,000	174,000,000	571,000,000	509,000,000
Operating income			423,000,000	300,000,000	948,000,000	763,000,000
Interest expense			(106,000,000)	(56,000,000)	(311,000,000)	(161,000,000)
Income (loss) from continuing operations before income taxes and equity earnings			337,000,000	269,000,000	700,000,000	682,000,000
Income tax expense			(71,000,000)	(53,000,000)	(111,000,000)	(151,000,000)
Net income			266,000,000	216,000,000	589,000,000	531,000,000
Earnings attributable to noncontrolling interests			(3,000,000)	(11,000,000)	$ (7,000,000)	(10,000,000)
San Diego Gas and Electric Company [Member] | Variable Interest Entity, Primary Beneficiary
Variable Interest Entities [Line Items]
Equity of variable interest entity							$ 100,000,000
Oncor Electric Delivery Company LLC. [Member]
Variable Interest Entities [Line Items]
Acquired percentage interest		80.25%
Sempra Texas Holdings Corp [Member] | Oncor Holdings [Member] | Sempra Texas Intermediate Holding Company LLC [Member]
Variable Interest Entities [Line Items]
Ownership percentage in consolidated entity		100.00%
Sempra Texas Holdings Corp [Member] | Oncor Electric Delivery Company LLC. [Member]
Variable Interest Entities [Line Items]
Acquired percentage interest		80.03%
Otay Mesa VIE [Member] | Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entities [Line Items]
Cash and cash equivalents	$ 8,000,000
Accounts receivable, net	11,000,000
Inventories	4,000,000
Total current assets	23,000,000
Property, plant and equipment, net	272,000,000
Other noncurrent assets	27,000,000
Total assets	322,000,000
Accounts payable	10,000,000
Other	2,000,000
Total current liabilities	12,000,000
Asset retirement obligations	2,000,000
Deferred credits and other	27,000,000
Asset Retirement Obligations And Deferred Credits And Other Liabilities	29,000,000
Other noncontrolling interests	281,000,000
Total liabilities and equity	322,000,000
Otay Mesa VIE [Member] | San Diego Gas and Electric Company [Member] | Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entities [Line Items]
Gain recognized upon deconsolidation	$ 0
Otay Mesa VIE [Member] | San Diego Gas and Electric Company [Member] | Variable Interest Entity, Primary Beneficiary
Variable Interest Entities [Line Items]
Generating capacity | MW					605
Conditional purchase obligation			280,000,000		$ 280,000,000
Cost of electric fuel and purchased power			(17,000,000)	(28,000,000)	(52,000,000)	(60,000,000)
Operation and maintenance			2,000,000	3,000,000	10,000,000	11,000,000
Depreciation and amortization			8,000,000	8,000,000	23,000,000	23,000,000
Total operating expenses			(7,000,000)	(17,000,000)	(19,000,000)	(26,000,000)
Operating income			7,000,000	17,000,000	19,000,000	26,000,000
Interest expense			(4,000,000)	(6,000,000)	(12,000,000)	(16,000,000)
Net income			3,000,000	11,000,000	7,000,000	10,000,000
Earnings attributable to noncontrolling interests			(3,000,000)	(11,000,000)	(7,000,000)	(10,000,000)
Earnings attributable to common shares			$ 0	$ 0	$ 0	$ 0

[1] Derived from audited financial statements.