OTHER FINANCIAL DATA - INCOME TAXES (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended			6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011		Jun. 30, 2012	Jun. 30, 2011
Income Tax Expense And Effective Income Tax Rates Disclosure [Line Items]
Income tax expense (benefit)	$ (118)	$ 100	[1]	$ (1)	$ 214	[1]
Effective income tax rate	227.00%	17.00%			23.00%
Remeasurement of equity method investments		277	[1]		277	[1]
Income taxes related to impairment of Rockies Express	121			121
Income tax benefit associated with life insurance contracts	54			54
San Diego Gas and Electric Company and Subsidiary [Member]
Income Tax Expense And Effective Income Tax Rates Disclosure [Line Items]
Income tax expense (benefit)	53	42		113	91
Effective income tax rate	34.00%	44.00%		35.00%	38.00%
Southern California Gas Company [Member]
Income Tax Expense And Effective Income Tax Rates Disclosure [Line Items]
Income tax expense (benefit)	$ 28	$ 28		$ 68	$ 65
Effective income tax rate	34.00%	32.00%		36.00%	34.00%

[1] As adjusted for the retrospective effect of a change in accounting principle as we discuss in Note 1.