OTHER FINANCIAL DATA - SHAREHOLDER'S EQUITY AND NONCONTROLLING INTEREST (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2016		Mar. 31, 2015
Equity, beginning of period		$ 12,579	[1]	$ 12,100
Comprehensive income (loss)		315		329
Share-based compensation expense		13		13
Common stock dividends declared		(188)		(173)
Issuance of common stock		28		30
Repurchases of common stock		(54)		(65)
Tax benefit related to share-based compensation		34		52
Distributions to noncontrolling interests		(3)		(5)
Equity, end of period		12,724		12,281
San Diego Gas and Electric Company [Member]
Equity, beginning of period		5,276	[1]	4,992
Comprehensive income (loss)		128		149
Distributions to noncontrolling interests		(1)		(3)
Equity, end of period		5,403		5,138
Southern California Gas Company [Member]
Equity, beginning of period	[1]	3,149
Equity, end of period		3,344
Total Shareholders' Equity [Member]
Equity, beginning of period		11,809		11,326
Comprehensive income (loss)		304		321
Share-based compensation expense		13		13
Common stock dividends declared		(188)		(173)
Issuance of common stock		28		30
Repurchases of common stock		(54)		(65)
Tax benefit related to share-based compensation		34		52
Distributions to noncontrolling interests		0		0
Equity, end of period		11,946		11,504
Total Shareholders' Equity [Member] | San Diego Gas and Electric Company [Member]
Equity, beginning of period		5,223		4,932
Comprehensive income (loss)		129		147
Distributions to noncontrolling interests		0		0
Equity, end of period		5,352		5,079
Noncontrolling Interests [Member]
Equity, beginning of period	[2]	770		774
Comprehensive income (loss)	[2]	11		8
Share-based compensation expense	[2]	0		0
Common stock dividends declared	[2]	0		0
Issuance of common stock	[2]	0		0
Repurchases of common stock	[2]	0		0
Tax benefit related to share-based compensation	[2]	0		0
Distributions to noncontrolling interests	[2]	(3)		(5)
Equity, end of period	[2]	778		777
Noncontrolling Interests [Member] | San Diego Gas and Electric Company [Member]
Equity, beginning of period		53		60
Comprehensive income (loss)		(1)		2
Distributions to noncontrolling interests		(1)		(3)
Equity, end of period		$ 51		$ 59

[1] Derived from audited financial statements.

[2] Noncontrolling interests include the preferred stock of SoCalGas and other noncontrolling interests as listed in the table below under "Other Noncontrolling Interests."