OTHER FINANCIAL DATA - INCOME TAXES (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Income Tax Expense And Effective Income Tax Rates Disclosure [Line Items]
Income tax expense (benefit)	$ 178	$ 117
Effective income tax rate	51.00%	33.00%
Income tax expense from corporate reorganization related to IEnova IPO	63
San Diego Gas and Electric Company and Subsidiary [Member]
Income Tax Expense And Effective Income Tax Rates Disclosure [Line Items]
Income tax expense (benefit)	51	60
Effective income tax rate	39.00%	35.00%
Southern California Gas Company [Member]
Income Tax Expense And Effective Income Tax Rates Disclosure [Line Items]
Income tax expense (benefit)	$ 24	$ 40
Effective income tax rate	34.00%	38.00%