GENERAL INFORMATION AND OTHER FINANCIAL DATA - VARIABLE INTEREST ENTITIES (Details) $ in Millions		3 Months Ended		6 Months Ended
	Mar. 09, 2018	Jun. 30, 2019 USD ($)	Jun. 30, 2018 USD ($)	Jun. 30, 2019 USD ($) MW	Jun. 30, 2018 USD ($)	Dec. 31, 2018 USD ($)
Variable Interest Entities [Line Items]
Energy-related businesses		$ 335	$ 355	$ 718	$ 701
Interest expense		(258)	(228)	(518)	(434)
Operation and maintenance		(838)	(742)	(1,670)	(1,483)
Depreciation and amortization		(389)	(377)	(772)	(749)
Income (loss) from continuing operations before income taxes and equity earnings (losses)		286	(1,183)	787	(590)
Income tax expense		(47)	602	(89)	360
Net income (loss)		435	(530)	953	(172)
(Earnings) losses attributable to noncontrolling interests		(45)	(5)	(86)	12
Equity method investment		10,930		10,930		$ 9,652	[1]
Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Assets of VIEs		651		651		286
Sempra Texas Utility [Member] | Oncor Holdings [Member]
Variable Interest Entities [Line Items]
Equity method investment		10,930		10,930		9,652
Sempra Renewables [Member] | Tax Equity Investors [Member]
Variable Interest Entities [Line Items]
Energy-related businesses		2	32	8	49
Operation and maintenance		0	(4)	(2)	(8)
Depreciation and amortization		(1)	(12)	(4)	(23)
Income (loss) from continuing operations before income taxes and equity earnings (losses)		1	16	2	18
Income tax expense		(1)	(7)	0	(12)
Net income (loss)		0	9	2	6
(Earnings) losses attributable to noncontrolling interests		2	20	(1)	41
Earnings attributable to common shares		2	29	1	47
Equity						158
Sempra Natural Gas [Member] | Cameron LNG Holdings [Member]
Variable Interest Entities [Line Items]
Equity method investment		1,242		1,242		1,271
San Diego Gas and Electric Company [Member]
Variable Interest Entities [Line Items]
Operation and maintenance		276	251	562	499
Depreciation and amortization		189	169	375	335
Operating income		263	215	525	463
Interest expense		(102)	(53)	(205)	(105)
Income (loss) from continuing operations before income taxes and equity earnings (losses)		181	188	363	413
Income tax expense		(35)	(42)	(40)	(98)
Net income (loss)		146	146	323	315
(Earnings) losses attributable to noncontrolling interests		(3)	0	$ (4)	1
San Diego Gas and Electric Company [Member] | Otay Mesa VIE [Member]
Variable Interest Entities [Line Items]
Generating capacity | MW				605
Conditional purchase obligation		280		$ 280
Equity of variable interest entity		103		103		$ 100
Secured debt of variable interest entity		211		211
Cost of electric fuel and purchased power		(19)	(16)	(35)	(32)
Operation and maintenance		4	4	8	8
Depreciation and amortization		8	7	15	15
Total operating expenses		(7)	(5)	(12)	(9)
Operating income		7	5	12	9
Interest expense		(4)	(5)	(8)	(10)
Net income (loss)		3	0	4	(1)
(Earnings) losses attributable to noncontrolling interests		(3)	0	(4)	1
Earnings attributable to common shares		$ 0	$ 0	$ 0	$ 0
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%

[1] Derived from audited financial statements.