OTHER FINANCIAL DATA - TRANSACTIONS WITH AFFILIATES (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013		Mar. 31, 2012	Dec. 31, 2012
San Diego Gas and Electric Company and Subsidiary [Member]
Transactions With Affiliates Disclosure [Line Items]
Due from affiliate, current	$ 1			$ 39
Due to affiliate, current	35			19
Revenues from unconsolidated affiliates	2		2
Southern California Gas Company [Member]
Transactions With Affiliates Disclosure [Line Items]
Due from affiliate, current	276			24
Revenues from unconsolidated affiliates	15		15
Affiliate Of Investee [Member] | Parent Company Member
Transactions With Affiliates Disclosure [Line Items]
Interest rate on due from affiliate, noncurrent	7.28%
Loan to unconsolidated affiliate, principal	18
Loan to unconsolidated affiliate, accrued interest	7
Due to/from Sempra Energy | San Diego Gas and Electric Company and Subsidiary [Member]
Transactions With Affiliates Disclosure [Line Items]
Due to affiliate, current	24			19
Income taxes due from (to) Sempra Energy	(7)	[1]		12	[1]
Due to/from Sempra Energy | Southern California Gas Company [Member]
Transactions With Affiliates Disclosure [Line Items]
Due from affiliate, current	265			24
Income taxes due from (to) Sempra Energy	93	[1]		99	[1]
Subsidiary Of Common Parent S D G E [Member] | Southern California Gas Company [Member]
Transactions With Affiliates Disclosure [Line Items]
Due from affiliate, current	11
Due to affiliate, current				37
Subsdiary Of Common Parent So Cal Gas [Member] | San Diego Gas and Electric Company and Subsidiary [Member]
Transactions With Affiliates Disclosure [Line Items]
Due from affiliate, current				37
Due to affiliate, current	11
Subsidiary Of Common Parent Other Affiliates [Member] | San Diego Gas and Electric Company and Subsidiary [Member]
Transactions With Affiliates Disclosure [Line Items]
Due from affiliate, current	$ 1			$ 2

[1] 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 the companies’ having always filed a separate return.