REGULATORY MATTERS - REGULATORY ACCOUNTS (Details) - USD ($) $ in Millions	2 Months Ended	12 Months Ended
	Feb. 27, 2018	Dec. 31, 2017	Dec. 31, 2016		Dec. 31, 2015
Schedule Of Net Regulatory Assets (Liabilities) [Line Items]
Write-off of wildfire regulatory asset		$ 351	$ 0	[1]	$ 0	[1]
U.S. federal statutory income tax rate		35.00%	35.00%		35.00%
Amortization expense on regulatory assets		$ 50	$ 65		$ 62
Sempra Mexico [Member]
Schedule Of Net Regulatory Assets (Liabilities) [Line Items]
Net regulatory assets (liabilities)		83	71
Net Regulatory Assets (Liabilities) Sempra Energy Consolidated [Member]
Schedule Of Net Regulatory Assets (Liabilities) [Line Items]
Net regulatory assets (liabilities)		(2,189)	764
San Diego Gas and Electric Company [Member]
Schedule Of Net Regulatory Assets (Liabilities) [Line Items]
Regulatory balancing accounts - net undercollected, Noncurrent		63
Write-off of wildfire regulatory asset		$ 351	$ 0	[1]	$ 0	[1]
U.S. federal statutory income tax rate		35.00%	35.00%		35.00%
Amortization expense on regulatory assets		$ 49	$ 63		$ 60
San Diego Gas and Electric Company [Member] | Fixed-price contracts and other derivatives [Member]
Schedule Of Net Regulatory Assets (Liabilities) [Line Items]
Net regulatory assets (liabilities)		96	141
San Diego Gas and Electric Company [Member] | Costs related to SONGS plant closure [Member]
Schedule Of Net Regulatory Assets (Liabilities) [Line Items]
Net regulatory assets (liabilities)		0	183
San Diego Gas and Electric Company [Member] | Costs related to wildfire litigation [Member]
Schedule Of Net Regulatory Assets (Liabilities) [Line Items]
Net regulatory assets (liabilities)		0	353
San Diego Gas and Electric Company [Member] | Deferred income taxes (refundable) recoverable in rates [Member]
Schedule Of Net Regulatory Assets (Liabilities) [Line Items]
Net regulatory assets (liabilities)		(281)	1,014
San Diego Gas and Electric Company [Member] | Pension and other postretirement benefit plan obligations [Member]
Schedule Of Net Regulatory Assets (Liabilities) [Line Items]
Net regulatory assets (liabilities)		153	210
San Diego Gas and Electric Company [Member] | Removal obligations [Member]
Schedule Of Net Regulatory Assets (Liabilities) [Line Items]
Net regulatory assets (liabilities)		(1,846)	(1,725)
San Diego Gas and Electric Company [Member] | Unamortized loss on reacquired debt [Member]
Schedule Of Net Regulatory Assets (Liabilities) [Line Items]
Net regulatory assets (liabilities)		$ 9	12
San Diego Gas and Electric Company [Member] | Unamortized loss on reacquired debt [Member] | Maximum [Member]
Schedule Of Net Regulatory Assets (Liabilities) [Line Items]
Remaining amortization period		10 years
San Diego Gas and Electric Company [Member] | Unamortized loss on reacquired debt [Member] | Minimum [Member]
Schedule Of Net Regulatory Assets (Liabilities) [Line Items]
Remaining amortization period		1 year
San Diego Gas and Electric Company [Member] | Environmental costs [Member]
Schedule Of Net Regulatory Assets (Liabilities) [Line Items]
Net regulatory assets (liabilities)		$ 29	48
San Diego Gas and Electric Company [Member] | Legacy meters [Member]
Schedule Of Net Regulatory Assets (Liabilities) [Line Items]
Net regulatory assets (liabilities)		0	16
San Diego Gas and Electric Company [Member] | Sunrise Powerlink fire mitigation [Member]
Schedule Of Net Regulatory Assets (Liabilities) [Line Items]
Net regulatory assets (liabilities)		$ 119	118
Remaining amortization period		52-year
San Diego Gas and Electric Company [Member] | Regulatory Balancing Accounts, Commodity – electric [Member]
Schedule Of Net Regulatory Assets (Liabilities) [Line Items]
Net regulatory assets (liabilities)		$ 82	35
San Diego Gas and Electric Company [Member] | Regulatory Balancing Accounts, Gas transportation [Member]
Schedule Of Net Regulatory Assets (Liabilities) [Line Items]
Net regulatory assets (liabilities)		22	61
San Diego Gas and Electric Company [Member] | Regulatory Balancing Accounts, Safety and reliability [Member]
Schedule Of Net Regulatory Assets (Liabilities) [Line Items]
Net regulatory assets (liabilities)		48	20
San Diego Gas and Electric Company [Member] | Regulatory Balancing Accounts, Public purpose programs [Member]
Schedule Of Net Regulatory Assets (Liabilities) [Line Items]
Net regulatory assets (liabilities)		(70)	(106)
San Diego Gas and Electric Company [Member] | Regulatory Balancing Accounts, Other balancing accounts [Member]
Schedule Of Net Regulatory Assets (Liabilities) [Line Items]
Net regulatory assets (liabilities)		233	249
San Diego Gas and Electric Company [Member] | Other regulatory (liabilities) assets [Member]
Schedule Of Net Regulatory Assets (Liabilities) [Line Items]
Net regulatory assets (liabilities)		(70)	(2)
San Diego Gas and Electric Company [Member] | Net Regulatory Assets (Liabilities) SDGE [Member]
Schedule Of Net Regulatory Assets (Liabilities) [Line Items]
Net regulatory assets (liabilities)		(1,476)	627
Southern California Gas Company [Member]
Schedule Of Net Regulatory Assets (Liabilities) [Line Items]
Regulatory balancing accounts - net undercollected, Noncurrent		$ 118	$ 85
U.S. federal statutory income tax rate		35.00%	35.00%		35.00%
Amortization expense on regulatory assets		$ 1	$ 2		$ 2
Southern California Gas Company [Member] | Deferred income taxes (refundable) recoverable in rates [Member]
Schedule Of Net Regulatory Assets (Liabilities) [Line Items]
Net regulatory assets (liabilities)		(437)	417
Southern California Gas Company [Member] | Pension and other postretirement benefit plan obligations [Member]
Schedule Of Net Regulatory Assets (Liabilities) [Line Items]
Net regulatory assets (liabilities)		513	563
Southern California Gas Company [Member] | Employee benefit costs [Member]
Schedule Of Net Regulatory Assets (Liabilities) [Line Items]
Net regulatory assets (liabilities)		45	45
Southern California Gas Company [Member] | Removal obligations [Member]
Schedule Of Net Regulatory Assets (Liabilities) [Line Items]
Net regulatory assets (liabilities)		(924)	(972)
Southern California Gas Company [Member] | Unamortized loss on reacquired debt [Member]
Schedule Of Net Regulatory Assets (Liabilities) [Line Items]
Net regulatory assets (liabilities)		$ 8	10
Southern California Gas Company [Member] | Unamortized loss on reacquired debt [Member] | Maximum [Member]
Schedule Of Net Regulatory Assets (Liabilities) [Line Items]
Remaining amortization period		8 years
Southern California Gas Company [Member] | Unamortized loss on reacquired debt [Member] | Minimum [Member]
Schedule Of Net Regulatory Assets (Liabilities) [Line Items]
Remaining amortization period		3 years
Southern California Gas Company [Member] | Environmental costs [Member]
Schedule Of Net Regulatory Assets (Liabilities) [Line Items]
Net regulatory assets (liabilities)		$ 22	22
Southern California Gas Company [Member] | Workers’ compensation [Member]
Schedule Of Net Regulatory Assets (Liabilities) [Line Items]
Net regulatory assets (liabilities)		12	10
Southern California Gas Company [Member] | Regulatory Balancing Accounts, Commodity - gas including transportation
Schedule Of Net Regulatory Assets (Liabilities) [Line Items]
Net regulatory assets (liabilities)		151	207
Southern California Gas Company [Member] | Regulatory Balancing Accounts, Safety and reliability [Member]
Schedule Of Net Regulatory Assets (Liabilities) [Line Items]
Net regulatory assets (liabilities)		266	230
Southern California Gas Company [Member] | Regulatory Balancing Accounts, Public purpose programs [Member]
Schedule Of Net Regulatory Assets (Liabilities) [Line Items]
Net regulatory assets (liabilities)		(274)	(270)
Southern California Gas Company [Member] | Regulatory Balancing Accounts, Other balancing accounts [Member]
Schedule Of Net Regulatory Assets (Liabilities) [Line Items]
Net regulatory assets (liabilities)		(114)	(204)
Southern California Gas Company [Member] | Other regulatory (liabilities) assets [Member]
Schedule Of Net Regulatory Assets (Liabilities) [Line Items]
Net regulatory assets (liabilities)		(64)	8
Southern California Gas Company [Member] | Net Regulatory Assets (Liabilities) SoCalGas [Member]
Schedule Of Net Regulatory Assets (Liabilities) [Line Items]
Net regulatory assets (liabilities)		(796)	$ 66
Loss from Catastrophes [Member] | San Diego Gas and Electric Company [Member]
Schedule Of Net Regulatory Assets (Liabilities) [Line Items]
Write-off of wildfire regulatory asset		$ 351
Subsequent Event [Member]
Schedule Of Net Regulatory Assets (Liabilities) [Line Items]
U.S. federal statutory income tax rate	21.00%

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