DERIVATIVE FINANCIAL INSTRUMENTS 2 (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2013	Dec. 31, 2012
Cash Flow Hedges
Schedule Of Notional Amounts Of Interest Rate Derivatives [Line Items]
Notional amount of interest rate derivatives	$ 436	$ 439
Maturities of interest rate derivatives, minimum	2013	2013
Maturities of interest rate derivatives, maximum	2028	2028
Fair Value Hedges
Schedule Of Notional Amounts Of Interest Rate Derivatives [Line Items]
Notional amount of interest rate derivatives	500	500
Maturities of interest rate derivatives, minimum	2013	2013
Maturities of interest rate derivatives, maximum	2016	2016
San Diego Gas and Electric Company and Subsidiary [Member] | Cash Flow Hedges
Schedule Of Notional Amounts Of Interest Rate Derivatives [Line Items]
Notional amount of interest rate derivatives	$ 342	$ 345
Maturities of interest rate derivatives	2019	2019