FAIR VALUE MEASUREMENTS 3 (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013		Dec. 31, 2012
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nuclear decommissioning trusts - equity securities	$ 559		$ 539
Nuclear decommissioning trusts - Debt securities issued by the U.S. Treasury and other U.S. government corporations and agencies	164		156
Nuclear decomissioning trusts - Municipal debt securities	74		63
Nuclear decommissioning trusts - Other debt securities	136		130
Nuclear decommissioning trusts - Total debt securities	374		349
Total nuclear decommissioning trusts	933	[1]	888	[1]
Interest rate instruments, assets	73		68
Commodity contracts subject to rate recovery, assets	59		74
Commodity contracts not subject to rate recovery, assets	32		43
Investments			1
Total fair value of assets measured on a recurring basis	1,097		1,074
Interest rate instruments, liabilities	124		126
Commodity contracts subject to rate recovery, liabilities	9		9
Commodity contracts not subject to rate recovery, liabilities	14		18
Total fair value of liabilities measured on a recurring basis	147		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	559		539
Nuclear decommissioning trusts - Debt securities issued by the U.S. Treasury and other U.S. government corporations and agencies	164		156
Nuclear decomissioning trusts - Municipal debt securities	74		63
Nuclear decommissioning trusts - Other debt securities	136		130
Nuclear decommissioning trusts - Total debt securities	374		349
Total nuclear decommissioning trusts	933	[1]	888	[1]
Commodity contracts subject to rate recovery, assets	57		73
Commodity contracts not subject to rate recovery, assets	2		1
Total fair value of assets measured on a recurring basis	992		962
Interest rate instruments, liabilities	60		81
Commodity contracts subject to rate recovery, liabilities	8		8
Total fair value of liabilities measured on a recurring basis	68		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	2		1
Commodity contracts not subject to rate recovery, assets	3		3
Total fair value of assets measured on a recurring basis	5		4
Commodity contracts subject to rate recovery, liabilities	1		1
Total fair value of liabilities measured on a recurring basis	1		1
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nuclear decommissioning trusts - equity securities	559		539
Nuclear decommissioning trusts - Debt securities issued by the U.S. Treasury and other U.S. government corporations and agencies	94		87
Nuclear decommissioning trusts - Total debt securities	94		87
Total nuclear decommissioning trusts	653	[1]	626	[1]
Commodity contracts subject to rate recovery, assets	12		13
Commodity contracts not subject to rate recovery, assets	29		28
Investments			1
Total fair value of assets measured on a recurring basis	694		668
Commodity contracts subject to rate recovery, liabilities	17		23
Commodity contracts not subject to rate recovery, liabilities	1		6
Total fair value of liabilities measured on a recurring basis	18		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	559		539
Nuclear decommissioning trusts - Debt securities issued by the U.S. Treasury and other U.S. government corporations and agencies	94		87
Nuclear decommissioning trusts - Total debt securities	94		87
Total nuclear decommissioning trusts	653	[1]	626	[1]
Commodity contracts subject to rate recovery, assets	10		12
Commodity contracts not subject to rate recovery, assets	2		1
Total fair value of assets measured on a recurring basis	665		639
Commodity contracts subject to rate recovery, liabilities	17		23
Total fair value of liabilities measured on a recurring basis	17		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	3		3
Total fair value of assets measured on a recurring basis	5		4
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	70		69
Nuclear decomissioning trusts - Municipal debt securities	74		63
Nuclear decommissioning trusts - Other debt securities	136		130
Nuclear decommissioning trusts - Total debt securities	280		262
Total nuclear decommissioning trusts	280	[1]	262	[1]
Interest rate instruments, assets	73		68
Commodity contracts not subject to rate recovery, assets	13		15
Total fair value of assets measured on a recurring basis	366		345
Interest rate instruments, liabilities	124		126
Commodity contracts subject to rate recovery, liabilities	9		9
Commodity contracts not subject to rate recovery, liabilities	14		23
Total fair value of liabilities measured on a recurring basis	147		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	70		69
Nuclear decomissioning trusts - Municipal debt securities	74		63
Nuclear decommissioning trusts - Other debt securities	136		130
Nuclear decommissioning trusts - Total debt securities	280		262
Total nuclear decommissioning trusts	280	[1]	262	[1]
Total fair value of assets measured on a recurring basis	280		262
Interest rate instruments, liabilities	60		81
Commodity contracts subject to rate recovery, liabilities	8		8
Total fair value of liabilities measured on a recurring basis	68		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, liabilities	1		1
Total fair value of liabilities measured on a recurring basis	1		1
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commodity contracts subject to rate recovery, assets	47		61
Commodity contracts not subject to rate recovery, assets	(10)
Total fair value of assets measured on a recurring basis	37		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	47		61
Total fair value of assets measured on a recurring basis	47		61
Collateral Netted [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commodity contracts subject to rate recovery, liabilities	(17)		(23)
Commodity contracts not subject to rate recovery, liabilities	(1)		(11)
Total fair value of liabilities measured on a recurring basis	(18)		(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	(17)		(23)
Total fair value of liabilities measured on a recurring basis	$ (17)		$ (23)

[1] Excludes cash balances and cash equivalents.