CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (USD $) In Millions, except Share data in Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
REVENUES
Utilities	$ 2,334	$ 2,091
Energy-related businesses	316	292
Total revenues	2,650	2,383
Utilities [Abstract]
Cost of natural gas	(556)	(431)
Cost of electric fuel and purchased power	(447)	(388)
Energy-related businesses [Abstract]
Cost of natural gas, electric fuel and purchased power	(111)	(129)
Other cost of sales	(48)	(33)
Operation and maintenance	(724)	(671)
Depreciation and amortization	(295)	(257)
Franchise fees and other taxes	(106)	(96)
Gains on sale of assets	74
Equity (losses) earnings before income tax
Equity (losses) earnings before income tax, other	10	12
Other income (expense), net	37	75
Interest income	6	5
Interest expense	(138)	(113)
Income before income taxes and equity earnings of certain unconsolidated subsidiaries	352	357
Income tax (expense) benefit	(178)	(117)
Equity earnings, net of income tax	4	11
Net income	178	251
Losses (earnings) attributable to noncontrolling interests	2	(13)
Preferred dividends of subsidiaries	(2)	(2)
Earnings	178	236
Basic earnings per common share:
Basic earnings per common share	$ 0.73	$ 0.98
Basic earnings per common share, weighted-average number of shares outstanding (thousands)	243,294	240,566
Diluted earnings per common share:
Diluted earnings per common share	$ 0.72	$ 0.97
Diluted earnings per common share, weighted-average number of shares outstanding (thousands)	247,534	243,761
Dividends declared per share of common stock	$ 0.63	$ 0.60
San Diego Gas and Electric Company and Subsidiary [Member]
Utility operating revenues
Electric	772	671
Natural gas	167	163
Total utility operating revenues	939	834
Utility operating expenses
Utility cost of natural gas	76	67
Utility cost of electric fuel and purchased power	209	163
Utility operation and maintenance	297	268
Utility depreciation and amortization	134	112
Utility franchise fees and other taxes	55	46
Total utility operating expenses	771	656
Utility operating income	168	178
Equity (losses) earnings before income tax
Other income (expense), net	11	30
Interest income	1
Interest expense	(48)	(36)
Income before income taxes and equity earnings of certain unconsolidated subsidiaries	132	172
Income tax (expense) benefit	(51)	(60)
Net income	81	112
Losses (earnings) attributable to noncontrolling interests	11	(6)
Earnings	92	106
Preferred dividend requirements	(1)	(1)
Earnings attributable to common shares	91	105
Southern California Gas Company [Member]
Utility operating revenues
Total utility operating revenues	983	880
Utility operating expenses
Utility cost of natural gas	454	349
Utility operation and maintenance	306	289
Utility depreciation and amortization	100	87
Utility franchise fees and other taxes	40	36
Total utility operating expenses	900	761
Utility operating income	83	119
Equity (losses) earnings before income tax
Other income (expense), net	4	4
Interest income		0
Interest expense	(17)	(17)
Income before income taxes and equity earnings of certain unconsolidated subsidiaries	70	106
Income tax (expense) benefit	(24)	(40)
Net income	46	66
Earnings	46	66
Earnings attributable to common shares	$ 46	$ 66