ACQUISTION AND DIVESTITURE ACTIVITY - ACQUISITION ACTIVITY (Details) $ / shares in Units, bbl in Thousands, $ in Millions										1 Months Ended	3 Months Ended		9 Months Ended
	Oct. 18, 2018 USD ($) $ / shares	Jul. 13, 2018 shares	Jun. 29, 2018 USD ($) kv	Mar. 09, 2018 USD ($)	Mar. 08, 2018 USD ($) shares	Feb. 28, 2018 USD ($) MW	Jan. 12, 2018 USD ($)	Jan. 09, 2018 shares	Jul. 10, 2017 USD ($) ppa MW	Jan. 31, 2018 USD ($)	Jun. 30, 2018 USD ($) shares	Mar. 31, 2018 USD ($) shares	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)	[1]	Sep. 26, 2018 USD ($) bbl	Sep. 20, 2018 USD ($)
Business Acquisition [Line Items]
Cash paid, net of cash and cash equivalents acquired													$ (9,566)	$ 0
Repayments of debt							$ 800			$ 800
Issuances of common stock, net of $41 in offering costs in 2018													$ 2,261	$ 37
Oncor Electric Delivery Company LLC. [Member]
Business Acquisition [Line Items]
Acquired percentage interest				80.25%
Oncor Holdings [Member]
Business Acquisition [Line Items]
Consideration				$ 9,566
Fisterra Midstream Mexico [Member] | Sempra Mexico [Member]
Business Acquisition [Line Items]
Cash consideration						$ 5
Commitment to invest						$ 130
Generating capacity | MW						125
Term of power purchase agreement						15 years
Oncor Electric Delivery Company LLC Additional Acquisition [Member] | Sempra Texas Intermediate Holding Company LLC [Member] | Oncor Holdings [Member]
Business Acquisition [Line Items]
Cash consideration				$ 26
Oncor Electric Delivery Company LLC Additional Acquisition [Member] | Oncor Electric Delivery Company LLC. [Member] | Oncor Holdings [Member]
Business Acquisition [Line Items]
Acquired percentage interest				0.22%
Ownership percentage in consolidated entity				0.22%
Consideration				$ 26
Sempra Texas Holdings Corp [Member]
Business Acquisition [Line Items]
Proceeds from Issuance of Debt and Equity										$ 7,000
Proceeds from issuance of debt							$ 4,900
Sempra Texas Holdings Corp [Member] | Oncor Electric Delivery Company LLC. [Member]
Business Acquisition [Line Items]
Acquired percentage interest				80.03%
Sempra Texas Holdings Corp [Member] | Sempra Texas Intermediate Holding Company LLC [Member] | Oncor Holdings [Member]
Business Acquisition [Line Items]
Ownership percentage in consolidated entity				100.00%
Sempra Texas Holdings Corp [Member] | Texas Transmission Investment LLC [Member] | Oncor Electric Delivery Company LLC. [Member]
Business Acquisition [Line Items]
Ownership percentage held by noncontrolling owners				19.75%
Sempra Texas Holdings Corp [Member] | Oncor Holdings [Member]
Business Acquisition [Line Items]
Cash consideration				$ 9,450
Adjustment for dividends				31
Transaction costs incurred				$ 59
Sempra Texas Holdings Corp [Member] | Oncor Holdings [Member] | Oncor Electric Delivery Company LLC. [Member]
Business Acquisition [Line Items]
Ownership percentage in consolidated entity				80.25%
Trafigura Mexico, S.A. de C.V. Subsidiary [Member] | Sempra Mexico [Member]
Business Acquisition [Line Items]
Acquired percentage interest																51.00%
Ownership percentage held by noncontrolling owners																49.00%
Availble percentage of voting interest acquirable																82.50%
Percent of terminal capacity contracted																50.00%
Terminal storage capacity | bbl																1,480
Trafigura Mexico, S.A. de C.V. Subsidiary [Member] | Sempra Mexico [Member] | Minimum [Member]
Business Acquisition [Line Items]
Commitment to invest																$ 102
Trafigura Mexico, S.A. de C.V. Subsidiary [Member] | Sempra Mexico [Member] | Maximum [Member]
Business Acquisition [Line Items]
Commitment to invest																$ 165
Great Valley Solar [Member] | Sempra Renewables [Member]
Business Acquisition [Line Items]
Cash consideration									$ 124
Generating capacity | MW									200
Number of PPAs | ppa									4
Term of power purchase agreement									18 years
InfraREIT Acquisition [Member] | Sempra Texas Utility [Member] | Subsequent Event [Member]
Business Acquisition [Line Items]
Consideration	$ 1,275
Acquisition price per share acquired | $ / shares	$ 21
Management agreement termination fee paid	$ 40
Debt assumed	$ 945
InfraREIT Acquisition [Member] | Sempra Texas Utility [Member] | InfraREIT [Member] | Subsequent Event [Member]
Business Acquisition [Line Items]
Acquired percentage interest	100.00%
InfraREIT Acquisition [Member] | Sempra Texas Utility [Member] | InfraREIT Partners [Member] | Subsequent Event [Member]
Business Acquisition [Line Items]
Acquired percentage interest	100.00%
Sharyland Holdings, LP [Member] | Subsequent Event [Member]
Business Acquisition [Line Items]
Commitment to invest	$ 1,025
Sharyland Holdings, LP [Member] | Sempra Texas Utility [Member] | Subsequent Event [Member]
Business Acquisition [Line Items]
Acquired percentage interest	50.00%
Consideration	$ 98
Sharyland Holdings, LP [Member] | Sempra Texas Utility [Member] | Sharyland Utilities [Member] | Subsequent Event [Member]
Business Acquisition [Line Items]
Acquired percentage interest	100.00%
Ownership percentage in consolidated entity	50.00%
Companía Transmisora del Norte Grande S.A. [Member] | Sempra South American Utilities [Member]
Business Acquisition [Line Items]
Acquired percentage interest			100.00%
Consideration			$ 220
Common Stock [Member]
Business Acquisition [Line Items]
Shares issued | shares		11,212,500			8,556,630			26,869,158			7,651,671	8,556,630
Common Stock [Member] | Settlement of Forward Sale Contracts [Member]
Business Acquisition [Line Items]
Issuances of common stock, net of $41 in offering costs in 2018					$ 900						$ 800	$ 900
Underwriting discount					16
Commercial Paper [Member] | Sempra Texas Holdings Corp [Member] | Oncor Holdings [Member]
Business Acquisition [Line Items]
Proceeds from issuance of debt					$ 2,600
Weighted average maturity					47 days
Weighted average interest rate					2.20%
Single-circuit Transmission Line [Member] | Companía Transmisora del Norte Grande S.A. [Member] | Sempra South American Utilities [Member]
Business Acquisition [Line Items]
Energy Transmission Voltage | kv			110
Double-circuit Transmission Line [Member] | Companía Transmisora del Norte Grande S.A. [Member] | Sempra South American Utilities [Member]
Business Acquisition [Line Items]
Energy Transmission Voltage | kv			220
Disposal Group Held-for-sale [Member] | Solar Assets and One Wind Generation Facility [Member] | Sempra Renewables [Member]
Business Acquisition [Line Items]
Consideration to be received																	$ 1,540

[1] As adjusted for the retrospective adoption of ASU 2016-15 and ASU 2016-18, which we discuss in Note 2.