ACQUISTION AND DIVESTITURE ACTIVITY - Sempra Mexico (Details) bbl in Thousands, $ in Millions						3 Months Ended								12 Months Ended
	Feb. 28, 2018 USD ($) MW	Nov. 15, 2017 USD ($)	Dec. 14, 2016 USD ($) MW	Oct. 13, 2016 USD ($)	Sep. 26, 2016 USD ($)	Dec. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Sep. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)		Dec. 31, 2016 USD ($)		Sep. 26, 2018 USD ($) bbl	Nov. 14, 2017	Sep. 25, 2016
Business Acquisition [Line Items]
Issuances of common stock, net of $41 in offering costs in 2018														$ 2,272	$ 47		$ 51
Cash paid, net of cash and cash equivalents acquired														(9,776)	(147)		(1,342)
Revenues						$ 3,221	$ 2,940	$ 2,564	$ 2,962	$ 2,964	$ 2,679	$ 2,533	$ 3,031	11,687	11,207	[1]	10,183	[1]
Earnings attributable to common shares						864	$ 274	$ (561)	$ 347	(501)	$ 57	$ 259	$ 441
Restricted cash						$ 56				$ 76				$ 56	$ 76
Sempra Mexico [Member] | Trafigura Mexico, S.A. de C.V. Subsidiary [Member]
Business Acquisition [Line Items]
Maximum ownership percentage available																			82.50%
Ownership percentage held by noncontrolling owners																			49.00%
Terminal Services Agreement, percent of terminal capacity																			50.00%
Terminal storage capacity | bbl																			1,480
Acquired percentage interest																			51.00%
Sempra Mexico [Member] | Fisterra Midstream Mexico [Member]
Business Acquisition [Line Items]
Commitment to invest	$ 130
Cash consideration (fair value of total consideration)	$ 5
Generating capacity (in mw) | MW	125
Power purchase agreement term	15 years
Sempra Mexico [Member] | Gasoductos De Chihuahua [Member]
Business Acquisition [Line Items]
Cash consideration (fair value of total consideration)					$ 1,144
Cash and cash equivalents					66
Other intangible assets					0
Sempra Mexico [Member] | Ventika Wind Power Generation Facilities [Member]
Business Acquisition [Line Items]
Cash consideration (fair value of total consideration)			$ 310
Cash and cash equivalents			0
Other intangible assets			$ 154
Minimum [Member] | Sempra Mexico [Member] | Trafigura Mexico, S.A. de C.V. Subsidiary [Member]
Business Acquisition [Line Items]
Commitment to invest																			$ 102
Maximum [Member] | Sempra Mexico [Member] | Trafigura Mexico, S.A. de C.V. Subsidiary [Member]
Business Acquisition [Line Items]
Commitment to invest																			$ 165
IEnova [Member]
Business Acquisition [Line Items]
Cash consideration (fair value of total consideration)				$ 351
IEnova [Member] | Ventika Wind Power Generation Facilities [Member]
Business Acquisition [Line Items]
Cash consideration (fair value of total consideration)				$ 50
IEnova [Member] | Sempra Mexico [Member]
Business Acquisition [Line Items]
Ownership percentage held by noncontrolling owners						33.50%				33.60%				33.50%	33.60%
IEnova [Member] | Sempra Mexico [Member] | Ductos Energéticos del Norte [Member]
Business Acquisition [Line Items]
Ownership percentage before acquisition																				50.00%
Cash paid, net of cash and cash equivalents acquired		$ 165
Cash acquired from acquisition		18
Debt assumed		$ 96
Ownership percentage in consolidated entity		100.00%
Ownership percentage in equity method investee																				50.00%
Other intangible assets		$ 66
Weighted average life of finite-lived intangible acquired		23 years
Acquired percentage interest		50.00%
IEnova [Member] | Sempra Mexico [Member] | Gasoductos De Chihuahua [Member]
Business Acquisition [Line Items]
Cash consideration (fair value of total consideration)					1,144
Cash and cash equivalents					66
Ownership percentage before acquisition																					50.00%
Cash paid, net of cash and cash equivalents acquired					1,078
Debt assumed					$ 364
Ownership percentage in consolidated entity					100.00%
Proceeds from debt issued					$ 1,150
Gain on acquisition of remaining voting rights																	617
Gain on acquisition of remaining voting rights, net of tax																	432
Accrued Merger-related transaction costs																	4
Revenues																	82
Earnings attributable to common shares																	33
Acquired percentage interest					50.00%
IEnova [Member] | Sempra Mexico [Member] | Ventika Wind Power Generation Facilities [Member]
Business Acquisition [Line Items]
Generating capacity (in mw) | MW			252
Power purchase agreement term			20 years
Issuances of common stock, net of $41 in offering costs in 2018			$ 50
Debt assumed			610
Proceeds from debt issued			$ 250
Accrued Merger-related transaction costs																	1
Revenues																	4
Earnings attributable to common shares																	$ 3
Acquired percentage interest			100.00%
Consideration transferred			$ 310
Cash			10
Restricted cash			$ 68
Ramones Norte Pipeline [Member] | IEnova [Member] | Sempra Mexico [Member]
Business Acquisition [Line Items]
Ownership percentage in equity method investee					25.00%
Ramones Norte Pipeline [Member] | IEnova [Member] | Sempra Mexico [Member] | Ductos Energéticos del Norte [Member]
Business Acquisition [Line Items]
Ownership percentage before acquisition		50.00%																		25.00%
Ownership percentage in consolidated entity		50.00%
Renewable energy and consumption permit [Member] | IEnova [Member] | Sempra Mexico [Member] | Ventika Wind Power Generation Facilities [Member]
Business Acquisition [Line Items]
Weighted average life of finite-lived intangible acquired			19 years

[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.