OTHER FINANCIAL DATA - VARIABLE INTEREST ENTITIES (Details) $ in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2017 USD ($)	Jun. 30, 2016 USD ($)		Jun. 30, 2017 USD ($) MW	Jun. 30, 2016 USD ($)		Dec. 31, 2016 USD ($)
Variable Interest Entities [Line Items]
Property, plant and equipment, net	$ 34,561			$ 34,561			$ 32,931	[1]
Other noncontrolling interests	2,253			2,253			2,270	[1]
Energy-related businesses	336	$ 162	[2]	669	$ 342	[2]
Other Cost and Expense, Operating	731	706	[2]	1,445	1,406	[2]
Depreciation and amortization	368	314	[2]	728	642	[2],[3]
Interest expense	(159)	(142)	[2]	(328)	(285)	[2]
Income before income taxes	415	(112)	[2]	1,170	343	[2]
Income tax (expense) benefit	(167)	106	[2]	(462)	(2)	[2]
Income (loss) before income taxes/Net income (loss)	248	27	[2]	700	391	[2],[3]
(Earnings) losses attributable to noncontrolling interest	12	(10)	[2]	1	(21)	[2]
Earnings attributable to common shares	259	16	[2]	700	369	[2]
Otay Mesa VIE [Member]
Variable Interest Entities [Line Items]
Property, plant and equipment, net	335			335			354
Sempra Renewables [Member] | Tax Equity Investors [Member]
Variable Interest Entities [Line Items]
Property, plant and equipment, net	912			912			926
Other noncontrolling interests	454			454			468
Energy-related businesses	18			31
Other Cost and Expense, Operating	7			9
Depreciation and amortization	8			16
Income before income taxes	3			6
Income tax (expense) benefit	(4)			(6)
Income (loss) before income taxes/Net income (loss)	(1)			0
(Earnings) losses attributable to noncontrolling interest	7			10
Earnings attributable to common shares	6			10
Sempra Natural Gas [Member] | Cameron LNG Holdings [Member]
Investments [Abstract]
Carrying value of equity method investment	977			977			997
San Diego Gas and Electric Company [Member]
Variable Interest Entities [Line Items]
Property, plant and equipment, net	14,215			14,215			13,250	[1]
Other noncontrolling interests	34			34			37	[1]
Operation and maintenance	237	266		464	512	[2]
Depreciation and amortization	166	158		329	317	[2]
Operating income (loss)	241	170		519	406	[2]
Interest expense	(49)	(48)		(98)	(96)	[2]
Income before income taxes	207	135		454	337	[2]
Income tax (expense) benefit	(54)	(48)		(144)	(113)	[2]
Income (loss) before income taxes/Net income (loss)	153	87		310	224	[2]
(Earnings) losses attributable to noncontrolling interest	(4)	13		$ (6)	12	[2]
San Diego Gas and Electric Company [Member] | Otay Mesa VIE [Member]
Variable Interest Entities [Line Items]
Power generating capacity | MW				605
Conditional purchase obligation	280			$ 280
Equity of variable interest entity	34			34			37
Secured debt of variable interest entity	300			300
Property, plant and equipment, net	335			335			$ 354
Cost of electric fuel and purchased power	(21)	(17)		(39)	(34)
Operation and maintenance	5	15		9	19
Depreciation and amortization	7	10		14	17
Total operating expenses	(9)	8		(16)	2
Operating income (loss)	9	(8)		16	(2)
Interest expense	(5)	(5)		(10)	(10)
Income (loss) before income taxes/Net income (loss)	4	(13)		6	(12)
(Earnings) losses attributable to noncontrolling interest	(4)	13		(6)	12
Earnings attributable to common shares	$ 0	$ 0		$ 0	$ 0

[1] Derived from audited financial statements.

[2] As adjusted for the adoption of ASU 2016-09 as of January 1, 2016.

[3] As adjusted for the adoption of ASU 2016-09 as of January 1, 2016.