FAIR VALUE MEASUREMENTS 3 (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012		Dec. 31, 2011
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nuclear decommissioning trusts - equity securities	$ 493		$ 468
Nuclear decommissioning trusts - Debt securities issued by the U.S. Treasury and other U.S. government corporations and agencies	155		170
Nuclear decomissioning trusts - Municipal debt securities	66		77
Nuclear decommissioning trusts - Other debt securities	85		78
Nuclear decommissioning trusts - Total debt securities	306		325
Total nuclear decommissioning trusts	799	[1]	793	[1]
Interest rate instruments, assets	70		66
Commodity contracts subject to rate recovery, assets	30		34
Commodity contracts not subject to rate recovery, assets	40		48
Investments	1		5
Total fair value of assets measured on a recurring basis	940		946
Interest rate instruments, liabilities	133		125
Commodity contracts subject to rate recovery, liabilities	14		13
Commodity contracts not subject to rate recovery, liabilities	38		49
Total fair value of liabilities measured on a recurring basis	185		187
San Diego Gas and Electric Company and Subsidiary [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nuclear decommissioning trusts - equity securities	493		468
Nuclear decommissioning trusts - Debt securities issued by the U.S. Treasury and other U.S. government corporations and agencies	155		170
Nuclear decomissioning trusts - Municipal debt securities	66		77
Nuclear decommissioning trusts - Other debt securities	85		78
Nuclear decommissioning trusts - Total debt securities	306		325
Total nuclear decommissioning trusts	799	[1]	793	[1]
Commodity contracts subject to rate recovery, assets	28		32
Commodity contracts not subject to rate recovery, assets	1		1
Total fair value of assets measured on a recurring basis	828		826
Interest rate instruments, liabilities	83		81
Commodity contracts subject to rate recovery, liabilities	12		12
Total fair value of liabilities measured on a recurring basis	95		93
Southern California Gas Company [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commodity contracts subject to rate recovery, assets	2		2
Commodity contracts not subject to rate recovery, assets	2		2
Total fair value of assets measured on a recurring basis	4		4
Commodity contracts subject to rate recovery, liabilities	2		1
Total fair value of liabilities measured on a recurring basis	2		1
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nuclear decommissioning trusts - equity securities	493		468
Nuclear decommissioning trusts - Debt securities issued by the U.S. Treasury and other U.S. government corporations and agencies	77		92
Nuclear decommissioning trusts - Total debt securities	77		92
Total nuclear decommissioning trusts	570	[1]	560	[1]
Commodity contracts subject to rate recovery, assets	17		10
Commodity contracts not subject to rate recovery, assets	16		15
Investments	1		5
Total fair value of assets measured on a recurring basis	604		590
Interest rate instruments, liabilities			1
Commodity contracts subject to rate recovery, liabilities	51		61
Commodity contracts not subject to rate recovery, liabilities	6		1
Total fair value of liabilities measured on a recurring basis	57		63
Level 1 | San Diego Gas and Electric Company and Subsidiary [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nuclear decommissioning trusts - equity securities	493		468
Nuclear decommissioning trusts - Debt securities issued by the U.S. Treasury and other U.S. government corporations and agencies	77		92
Nuclear decommissioning trusts - Total debt securities	77		92
Total nuclear decommissioning trusts	570	[1]	560	[1]
Commodity contracts subject to rate recovery, assets	15		9
Commodity contracts not subject to rate recovery, assets	1		1
Total fair value of assets measured on a recurring basis	586		570
Commodity contracts subject to rate recovery, liabilities	51		61
Total fair value of liabilities measured on a recurring basis	51		61
Level 1 | Southern California Gas Company [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commodity contracts subject to rate recovery, assets	2		1
Commodity contracts not subject to rate recovery, assets	2		2
Total fair value of assets measured on a recurring basis	4		3
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nuclear decommissioning trusts - Debt securities issued by the U.S. Treasury and other U.S. government corporations and agencies	78		78
Nuclear decomissioning trusts - Municipal debt securities	66		77
Nuclear decommissioning trusts - Other debt securities	85		78
Nuclear decommissioning trusts - Total debt securities	229		233
Total nuclear decommissioning trusts	229	[1]	233	[1]
Interest rate instruments, assets	70		66
Commodity contracts subject to rate recovery, assets			1
Commodity contracts not subject to rate recovery, assets	24		35
Total fair value of assets measured on a recurring basis	323		335
Interest rate instruments, liabilities	133		124
Commodity contracts subject to rate recovery, liabilities	14		13
Commodity contracts not subject to rate recovery, liabilities	41		52
Total fair value of liabilities measured on a recurring basis	188		189
Level 2 | San Diego Gas and Electric Company and Subsidiary [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nuclear decommissioning trusts - Debt securities issued by the U.S. Treasury and other U.S. government corporations and agencies	78		78
Nuclear decomissioning trusts - Municipal debt securities	66		77
Nuclear decommissioning trusts - Other debt securities	85		78
Nuclear decommissioning trusts - Total debt securities	229		233
Total nuclear decommissioning trusts	229	[1]	233	[1]
Total fair value of assets measured on a recurring basis	229		233
Interest rate instruments, liabilities	83		81
Commodity contracts subject to rate recovery, liabilities	12		12
Total fair value of liabilities measured on a recurring basis	95		93
Level 2 | Southern California Gas Company [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commodity contracts subject to rate recovery, assets			1
Total fair value of assets measured on a recurring basis			1
Commodity contracts subject to rate recovery, liabilities	2		1
Total fair value of liabilities measured on a recurring basis	2		1
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commodity contracts subject to rate recovery, assets	13		23
Total fair value of assets measured on a recurring basis	13		23
Level 3 | San Diego Gas and Electric Company and Subsidiary [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commodity contracts subject to rate recovery, assets	13		23
Total fair value of assets measured on a recurring basis	13		23
Collateral Netted [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commodity contracts not subject to rate recovery, assets			(2)
Total fair value of assets measured on a recurring basis			(2)
Commodity contracts subject to rate recovery, liabilities	(51)		(61)
Commodity contracts not subject to rate recovery, liabilities	(9)		(4)
Total fair value of liabilities measured on a recurring basis	(60)		(65)
Collateral Netted [Member] | San Diego Gas and Electric Company and Subsidiary [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commodity contracts subject to rate recovery, liabilities	(51)		(61)
Total fair value of liabilities measured on a recurring basis	$ (51)		$ (61)

[1] Excludes cash balances and cash equivalents.