FAIR VALUE MEASUREMENTS 3 (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013		Dec. 31, 2012
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nuclear decommissioning trusts - equity securities	$ 569		$ 539
Nuclear decommissioning trusts - Debt securities issued by the U.S. Treasury and other U.S. government corporations and agencies	177		156
Nuclear decomissioning trusts - Municipal debt securities	64		63
Nuclear decommissioning trusts - Other debt securities	134		130
Nuclear decommissioning trusts - Total debt securities	375		349
Total nuclear decommissioning trusts	944	[1]	888	[1]
Interest rate instruments, assets	65		68
Commodity contracts subject to rate recovery, assets	82		74
Commodity contracts not subject to rate recovery, assets	27		43
Investments			1
Total fair value of assets measured on a recurring basis	1,118		1,074
Interest rate instruments, liabilities	134		126
Commodity contracts subject to rate recovery, liabilities	3		9
Commodity contracts not subject to rate recovery, liabilities	19		18
Total fair value of liabilities measured on a recurring basis	156		153
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	569		539
Nuclear decommissioning trusts - Debt securities issued by the U.S. Treasury and other U.S. government corporations and agencies	177		156
Nuclear decomissioning trusts - Municipal debt securities	64		63
Nuclear decommissioning trusts - Other debt securities	134		130
Nuclear decommissioning trusts - Total debt securities	375		349
Total nuclear decommissioning trusts	944	[1]	888	[1]
Commodity contracts subject to rate recovery, assets	78		73
Commodity contracts not subject to rate recovery, assets	1		1
Total fair value of assets measured on a recurring basis	1,023		962
Interest rate instruments, liabilities	75		81
Commodity contracts subject to rate recovery, liabilities	3		8
Total fair value of liabilities measured on a recurring basis	78		89
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	4		1
Commodity contracts not subject to rate recovery, assets	2		3
Total fair value of assets measured on a recurring basis	6		4
Commodity contracts subject to rate recovery, liabilities			1
Total fair value of liabilities measured on a recurring basis			1
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nuclear decommissioning trusts - equity securities	569		539
Nuclear decommissioning trusts - Debt securities issued by the U.S. Treasury and other U.S. government corporations and agencies	106		87
Nuclear decommissioning trusts - Total debt securities	106		87
Total nuclear decommissioning trusts	675	[1]	626	[1]
Commodity contracts subject to rate recovery, assets	22		13
Commodity contracts not subject to rate recovery, assets	15		28
Investments			1
Total fair value of assets measured on a recurring basis	712		668
Commodity contracts subject to rate recovery, liabilities	12		23
Commodity contracts not subject to rate recovery, liabilities	15		6
Total fair value of liabilities measured on a recurring basis	27		29
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	569		539
Nuclear decommissioning trusts - Debt securities issued by the U.S. Treasury and other U.S. government corporations and agencies	106		87
Nuclear decommissioning trusts - Total debt securities	106		87
Total nuclear decommissioning trusts	675	[1]	626	[1]
Commodity contracts subject to rate recovery, assets	20		12
Commodity contracts not subject to rate recovery, assets	1		1
Total fair value of assets measured on a recurring basis	696		639
Commodity contracts subject to rate recovery, liabilities	11		23
Total fair value of liabilities measured on a recurring basis	11		23
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		3
Total fair value of assets measured on a recurring basis	4		4
Commodity contracts subject to rate recovery, liabilities	1
Total fair value of liabilities measured on a recurring basis	1
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	71		69
Nuclear decomissioning trusts - Municipal debt securities	64		63
Nuclear decommissioning trusts - Other debt securities	134		130
Nuclear decommissioning trusts - Total debt securities	269		262
Total nuclear decommissioning trusts	269	[1]	262	[1]
Interest rate instruments, assets	65		68
Commodity contracts subject to rate recovery, assets	2
Commodity contracts not subject to rate recovery, assets	12		15
Total fair value of assets measured on a recurring basis	348		345
Interest rate instruments, liabilities	134		126
Commodity contracts subject to rate recovery, liabilities	3		9
Commodity contracts not subject to rate recovery, liabilities	23		23
Total fair value of liabilities measured on a recurring basis	160		158
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	71		69
Nuclear decomissioning trusts - Municipal debt securities	64		63
Nuclear decommissioning trusts - Other debt securities	134		130
Nuclear decommissioning trusts - Total debt securities	269		262
Total nuclear decommissioning trusts	269	[1]	262	[1]
Total fair value of assets measured on a recurring basis	269		262
Interest rate instruments, liabilities	75		81
Commodity contracts subject to rate recovery, liabilities	3		8
Total fair value of liabilities measured on a recurring basis	78		89
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	2
Total fair value of assets measured on a recurring basis	2
Commodity contracts subject to rate recovery, liabilities			1
Total fair value of liabilities measured on a recurring basis			1
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commodity contracts subject to rate recovery, assets	58		61
Total fair value of assets measured on a recurring basis	58		61
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	58		61
Total fair value of assets measured on a recurring basis	58		61
Collateral Netted [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commodity contracts subject to rate recovery, liabilities	(12)		(23)
Commodity contracts not subject to rate recovery, liabilities	(19)		(11)
Total fair value of liabilities measured on a recurring basis	(31)		(34)
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	(11)		(23)
Total fair value of liabilities measured on a recurring basis	(11)		(23)
Collateral Netted [Member] | Southern California Gas Company [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commodity contracts subject to rate recovery, liabilities	(1)
Total fair value of liabilities measured on a recurring basis	$ (1)

[1] Excludes cash balances and cash equivalents.