OTHER FINANCIAL DATA - EARNINGS PER SHARE (Details) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2012		Sep. 30, 2011		Sep. 30, 2012	Sep. 30, 2011
Earnings Per Share Numerator [Abstract]
Earnings	$ 268		$ 289	[1]	$ 566	$ 1,046	[1]
Earnings Per Share Denominator [Abstract]
Weighted-average common shares outstanding for basic EPS	241,689,000		239,545,000	[1]	241,133,000	239,693,000	[1]
Dilutive effect of stock options, restricted stock awards and restricted stock units	4,113,000		2,335,000	[1]	3,880,000	2,262,000	[1]
Weighted-average common shares outstanding for diluted EPS	245,802,000		241,880,000	[1]	245,013,000	241,955,000	[1]
Earnings Per Share [Abstract]
Basic earnings per common share	$ 1.11		$ 1.21	[1]	$ 2.35	$ 4.36	[1]
Diluted earnings per common share	$ 1.09		$ 1.20	[1]	$ 2.31	$ 4.32	[1]
Seventy Fifth Percentile Or Above [Member]
Total Shareholder Return Ranking [Line Items]
Common Shares Received For Each Restricted Stock Unit	1.5	[2]
Fiftieth Percentile [Member]
Total Shareholder Return Ranking [Line Items]
Common Shares Received For Each Restricted Stock Unit	1	[2]
Thirty Fifth Percentile Or Below [Member]
Total Shareholder Return Ranking [Line Items]
Common Shares Received For Each Restricted Stock Unit	0	[2]
Restricted Stock Units [Member]
Schedule Of Performance Based Restricted Shares [Line Items]
Contractual vesting percentage maximum	150.00%
Restricted Stock Awards [Member]
Schedule Of Performance Based Restricted Shares [Line Items]
Contractual vesting percentage maximum	100.00%
Out Of The Money Stock Options [Member]
Antidilutive Securities Excluded From Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share			2,112,880		40,000	2,111,839
In The Money Stock Options
Antidilutive Securities Excluded From Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share						900
Restricted Stock
Antidilutive Securities Excluded From Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	2,349,338		3,473,578		2,523,343	3,630,253
Restricted Stock Units
Antidilutive Securities Excluded From Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	3,387		1,109		1,881
Restricted Stock Awards [Member]
Antidilutive Securities Excluded From Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share					14,319
San Diego Gas and Electric Company and Subsidiary [Member]
Earnings Per Share Numerator [Abstract]
Earnings	176		115		378	277
Southern California Gas Company [Member]
Earnings Per Share Numerator [Abstract]
Earnings	$ 71		$ 81		$ 191	$ 209

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

[2] (2) Participants may also receive additional shares for dividend equivalents on units subject to restricted stock units, which are reinvested to purchase additional units that become subject to the same vesting conditions as the restricted stock units to which the dividends relate.