OTHER FINANCIAL DATA - DUE TO DUE FROM AFFILIATES (Details) - USD ($) $ in Millions		3 Months Ended	12 Months Ended
		Mar. 31, 2016	Dec. 31, 2015
Transactions With Affiliates Disclosure [Line Items]
Due from affiliates, current		$ 7	$ 6	[1]
Due to affiliaties, current		(13)	(14)	[1]
Due from affiliate, noncurrent		186	186	[1]
San Diego Gas and Electric Company [Member]
Transactions With Affiliates Disclosure [Line Items]
Due from affiliates, current		1	1	[1]
Due to affiliaties, current		(49)	(55)	[1]
Southern California Gas Company [Member]
Transactions With Affiliates Disclosure [Line Items]
Due from affiliates, current		8	48	[1]
Due to affiliaties, current		(34)	0	[1]
Due to/from Sempra Energy | San Diego Gas and Electric Company [Member]
Transactions With Affiliates Disclosure [Line Items]
Due to affiliaties, current		(35)	(34)
Income taxes due to Sempra Energy	[2]	(32)
Income taxes due from Sempra Energy	[2]		28
Due to/from Sempra Energy | Southern California Gas Company [Member]
Transactions With Affiliates Disclosure [Line Items]
Due from affiliates, current		0	35	[3]
Due to affiliaties, current		(34)	0
Income taxes due to Sempra Energy	[2]	(23)
Income taxes due from Sempra Energy	[2]		$ 1
Interest rate on due from affiliate, noncurrent			0.11%
Loan to unconsolidated affiliate, principal			$ 50
Due to/from SDG&E | Southern California Gas Company [Member]
Transactions With Affiliates Disclosure [Line Items]
Due from affiliates, current		8	13
Due to/from SoCalGas | San Diego Gas and Electric Company [Member]
Transactions With Affiliates Disclosure [Line Items]
Due to affiliaties, current		$ (8)	(13)
Joint venture with PEMEX [Member]
Transactions With Affiliates Disclosure [Line Items]
Interest rate on due from affiliate, noncurrent		4.94%
PEMEX Four year loan C [Member]
Transactions With Affiliates Disclosure [Line Items]
Due from affiliate, noncurrent	[4],[5]	$ 8	8
PEMEX Three year loan A [Member]
Transactions With Affiliates Disclosure [Line Items]
Due from affiliate, noncurrent	[4],[5]	3	3
PEMEX Four year loan B [Member]
Transactions With Affiliates Disclosure [Line Items]
Due from affiliate, noncurrent	[4],[5]	34	34
PEMEX Four year loan A [Member]
Transactions With Affiliates Disclosure [Line Items]
Due from affiliate, noncurrent	[4],[5]	42	42
ESJ joint venture [Member]
Transactions With Affiliates Disclosure [Line Items]
Due from affiliate, noncurrent	[4],[6]	$ 17	24
Interest rate on due from affiliate, noncurrent		6.81%
Eletrans [Member]
Transactions With Affiliates Disclosure [Line Items]
Due from affiliate, noncurrent	[4],[7]	$ 76	72
Interest rate on due from affiliate, noncurrent		4.00%
Sempra South American Utilities [Member]
Transactions With Affiliates Disclosure [Line Items]
Due from affiliate, noncurrent		$ 1	0
Sempra Natural Gas Segment [Member]
Transactions With Affiliates Disclosure [Line Items]
Due from affiliate, noncurrent		5	3
Affiliate Of Investee [Member] | San Diego Gas and Electric Company [Member]
Transactions With Affiliates Disclosure [Line Items]
Due to affiliaties, current		$ (6)	$ (8)

[1] Derived from audited financial statements.

[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] At December 31, 2015, net receivable included outstanding advances to Sempra Energy of $50 million at an interest rate of 0.11 percent.

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

[5] U.S. dollar-denominated loan, at a variable interest rate based on a 30-day LIBOR plus 450 basis points (4.94 percent at March 31, 2016), to finance the Los Ramones Norte pipeline project.

[6] U.S. dollar-denominated loan, at a variable interest rate based on a 30-day LIBOR plus 637.5 basis points (6.81 percent at March 31, 2016), to finance the first phase of the Energía Sierra Juárez wind project.

[7] U.S. dollar-denominated loan, at a fixed interest rate with no stated maturity date, to provide project financing for the construction of transmission lines at Eletrans S.A. and Eletrans II S.A., both of which are joint ventures at Chilquinta Energía.