REVENUES - DISAGGREGATION OF REVENUE (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	[1]	Sep. 30, 2018	Sep. 30, 2017	[1]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	$ 2,992			$ 8,244
Utilities regulatory revenues	(195)			(131)
Other revenues	143			353
Total revenues	2,940	$ 2,679		8,466	$ 8,243
Over time [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	2,929			8,046
Point in time [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	63			198
Utilities service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	2,655			7,379
Midstream service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	205			550
Renewables service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	46			123
Other service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	86			192
Electric market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	1,972			4,780
Gas market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	1,020			3,464
Operating Segments [Member] | San Diego Gas and Electric Company [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	1,577			3,707
Utilities regulatory revenues	(278)			(302)
Other revenues	0			0
Total revenues	1,299			3,405
Operating Segments [Member] | San Diego Gas and Electric Company [Member] | Over time [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	1,549			3,625
Operating Segments [Member] | San Diego Gas and Electric Company [Member] | Point in time [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	28			82
Operating Segments [Member] | San Diego Gas and Electric Company [Member] | Utilities service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	1,577			3,707
Operating Segments [Member] | San Diego Gas and Electric Company [Member] | Midstream service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0			0
Operating Segments [Member] | San Diego Gas and Electric Company [Member] | Renewables service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0			0
Operating Segments [Member] | San Diego Gas and Electric Company [Member] | Other service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0			0
Operating Segments [Member] | San Diego Gas and Electric Company [Member] | Electric market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	1,486			3,335
Operating Segments [Member] | San Diego Gas and Electric Company [Member] | Gas market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	91			372
Operating Segments [Member] | Southern California Gas Company [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	719			2,529
Utilities regulatory revenues	83			171
Other revenues	0			0
Total revenues	802			2,700
Operating Segments [Member] | Southern California Gas Company [Member] | Over time [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	688			2,438
Operating Segments [Member] | Southern California Gas Company [Member] | Point in time [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	31			91
Operating Segments [Member] | Southern California Gas Company [Member] | Utilities service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	719			2,529
Operating Segments [Member] | Southern California Gas Company [Member] | Midstream service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0			0
Operating Segments [Member] | Southern California Gas Company [Member] | Renewables service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0			0
Operating Segments [Member] | Southern California Gas Company [Member] | Other service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0			0
Operating Segments [Member] | Southern California Gas Company [Member] | Electric market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0			0
Operating Segments [Member] | Southern California Gas Company [Member] | Gas market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	719			2,529
Operating Segments [Member] | Sempra South American Utilities [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	374			1,186
Utilities regulatory revenues	0			0
Other revenues	1			4
Total revenues	375			1,190
Operating Segments [Member] | Sempra South American Utilities [Member] | Over time [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	370			1,173
Operating Segments [Member] | Sempra South American Utilities [Member] | Point in time [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	4			13
Operating Segments [Member] | Sempra South American Utilities [Member] | Utilities service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	358			1,136
Operating Segments [Member] | Sempra South American Utilities [Member] | Midstream service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0			0
Operating Segments [Member] | Sempra South American Utilities [Member] | Renewables service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0			0
Operating Segments [Member] | Sempra South American Utilities [Member] | Other service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	16			50
Operating Segments [Member] | Sempra South American Utilities [Member] | Electric market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	374			1,186
Operating Segments [Member] | Sempra South American Utilities [Member] | Gas market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0			0
Operating Segments [Member] | Sempra Mexico [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	314			769
Utilities regulatory revenues	0			0
Other revenues	96			259
Total revenues	410			1,028
Operating Segments [Member] | Sempra Mexico [Member] | Over time [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	314			769
Operating Segments [Member] | Sempra Mexico [Member] | Point in time [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0			0
Operating Segments [Member] | Sempra Mexico [Member] | Utilities service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	17			58
Operating Segments [Member] | Sempra Mexico [Member] | Midstream service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	194			484
Operating Segments [Member] | Sempra Mexico [Member] | Renewables service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	32			85
Operating Segments [Member] | Sempra Mexico [Member] | Other service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	71			142
Operating Segments [Member] | Sempra Mexico [Member] | Electric market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	100			224
Operating Segments [Member] | Sempra Mexico [Member] | Gas market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	214			545
Operating Segments [Member] | Sempra Renewables [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	14			37
Utilities regulatory revenues	0			0
Other revenues	24			66
Total revenues	38			103
Operating Segments [Member] | Sempra Renewables [Member] | Over time [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	14			37
Operating Segments [Member] | Sempra Renewables [Member] | Point in time [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0			0
Operating Segments [Member] | Sempra Renewables [Member] | Utilities service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0			0
Operating Segments [Member] | Sempra Renewables [Member] | Midstream service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0			0
Operating Segments [Member] | Sempra Renewables [Member] | Renewables service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	14			37
Operating Segments [Member] | Sempra Renewables [Member] | Other service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0			0
Operating Segments [Member] | Sempra Renewables [Member] | Electric market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	14			37
Operating Segments [Member] | Sempra Renewables [Member] | Gas market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0			0
Operating Segments [Member] | Sempra LNG & Midstream [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	84			178
Utilities regulatory revenues	0			0
Other revenues	63			152
Total revenues	147			330
Operating Segments [Member] | Sempra LNG & Midstream [Member] | Over time [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	84			156
Operating Segments [Member] | Sempra LNG & Midstream [Member] | Point in time [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0			22
Operating Segments [Member] | Sempra LNG & Midstream [Member] | Utilities service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0			0
Operating Segments [Member] | Sempra LNG & Midstream [Member] | Midstream service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	82			171
Operating Segments [Member] | Sempra LNG & Midstream [Member] | Renewables service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	1			2
Operating Segments [Member] | Sempra LNG & Midstream [Member] | Other service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	1			5
Operating Segments [Member] | Sempra LNG & Midstream [Member] | Electric market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	2			7
Operating Segments [Member] | Sempra LNG & Midstream [Member] | Gas market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	82			171
Consolidating Adjustments [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	(90)			(162)
Utilities regulatory revenues	0			0
Other revenues	(41)			(128)
Total revenues	(131)			(290)
Consolidating Adjustments [Member] | Over time [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	(90)			(152)
Consolidating Adjustments [Member] | Point in time [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0			(10)
Consolidating Adjustments [Member] | Utilities service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	(16)			(51)
Consolidating Adjustments [Member] | Midstream service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	(71)			(105)
Consolidating Adjustments [Member] | Renewables service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	(1)			(1)
Consolidating Adjustments [Member] | Other service line [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	(2)			(5)
Consolidating Adjustments [Member] | Electric market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	(4)			(9)
Consolidating Adjustments [Member] | Gas market [Member]
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	$ (86)			$ (153)

[1] 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.