OTHER FINANCIAL DATA - TRANSACTIONS WITH AFFILIATES (Details) - USD ($) $ in Millions		3 Months Ended			9 Months Ended			12 Months Ended
		Sep. 30, 2015		Sep. 30, 2014	Sep. 30, 2015		Sep. 30, 2014	Dec. 31, 2014
Transactions With Affiliates Disclosure [Line Items]
Due from affiliate, noncurrent	[1]	$ 178			$ 178			$ 226
San Diego Gas and Electric Company [Member]
Transactions With Affiliates Disclosure [Line Items]
Due from affiliate, current		1			1			1
Due to affiliate, current		22			22			21
Revenues from unconsolidated affiliates		3		$ 2	8		$ 8
Southern California Gas Company [Member]
Transactions With Affiliates Disclosure [Line Items]
Due from affiliate, current		220			220			4
Due to affiliate, current		51			51			13
Revenues from unconsolidated affiliates		19		$ 17	55		$ 51
Due to/from Sempra Energy | San Diego Gas and Electric Company [Member]
Transactions With Affiliates Disclosure [Line Items]
Due to affiliate, current		22			22			17
Income taxes due from Sempra Energy	[2]				41			16
Due to/from Sempra Energy | Southern California Gas Company [Member]
Transactions With Affiliates Disclosure [Line Items]
Due from affiliate, current		220	[3]		220	[3]		0
Due to affiliate, current		0			0			13
Income taxes due from Sempra Energy	[2]				29			9
Loan to unconsolidated affiliate, principal		250			$ 250
Interest rate on due from affiliate, noncurrent					0.10%
Subsidiary Of Common Parent S D G E [Member] | Southern California Gas Company [Member]
Transactions With Affiliates Disclosure [Line Items]
Due from affiliate, current		0			$ 0			4
Due to affiliate, current		1			1			0
Subsdiary Of Common Parent So Cal Gas [Member] | San Diego Gas and Electric Company [Member]
Transactions With Affiliates Disclosure [Line Items]
Due from affiliate, current		1			1			0
Due to affiliate, current		0			0			4
Subsidiary Of Common Parent Other Affiliates [Member] | San Diego Gas and Electric Company [Member]
Transactions With Affiliates Disclosure [Line Items]
Due from affiliate, current		0			0			1
Subsidiary Of Common Parent Other Affiliates [Member] | Southern California Gas Company [Member]
Transactions With Affiliates Disclosure [Line Items]
Due to affiliate, current		$ 50			$ 50			$ 0

[1] Amounts include principal balances plus accumulated interest outstanding.

[2] SDG&E and SoCalGas are included in the consolidated income tax return of Sempra Energy and are allocated income tax expense from Sempra Energy in an amount equal to that which would result from each company having always filed a separate return.

[3] Net receivable includes a loan to Sempra Energy of $250 million at September 30, 2015 at an interest rate of 0.10 percent.