FAIR VALUE MEASUREMENTS - RECURRING FAIR VALUE MEASURES (Details) - USD ($) $ in Millions		Mar. 31, 2016	Dec. 31, 2015
Nuclear Decommisioning Trusts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nuclear decommissioning trusts - equity securities		$ 623	$ 619
Nuclear decommissioning trusts - Debt securities issued by the U.S. Treasury and other U.S. government corporations and agencies		105	91
Nuclear decommissioning trusts - Municipal bonds		156	156
Nuclear decommissioning trusts - Other securities		190	182
Nuclear decommissioning trusts - Total debt securities		451	429
Total nuclear decommissioning trusts	[1]	1,074	1,048
Derivative Financial Instruments Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate and foreign exchange instruments		8	5
Commodity contracts not subject to rate recovery, assets		40	34
Commodity contracts subject to rate recovery, assets		101	101
Total		1,223	1,188
Derivative Financial Instruments Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate and foreign exchange instruments		181	171
Commodity contracts not subject to rate recovery, liabilities		2	4
Commodity contracts subject to rate recovery, liabilities		69	67
Total		252	242
San Diego Gas and Electric Company [Member] | Nuclear Decommisioning Trusts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nuclear decommissioning trusts - equity securities		623	619
Nuclear decommissioning trusts - Debt securities issued by the U.S. Treasury and other U.S. government corporations and agencies		105	91
Nuclear decommissioning trusts - Municipal bonds		156	156
Nuclear decommissioning trusts - Other securities		190	182
Nuclear decommissioning trusts - Total debt securities		451	429
Total nuclear decommissioning trusts	[1]	1,074	1,048
San Diego Gas and Electric Company [Member] | Derivative Financial Instruments Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commodity contracts not subject to rate recovery, assets		2	1
Commodity contracts subject to rate recovery, assets		98	99
Total		1,174	1,148
San Diego Gas and Electric Company [Member] | Derivative Financial Instruments Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate instruments		39	37
Commodity contracts not subject to rate recovery, liabilities		0	0
Commodity contracts subject to rate recovery, liabilities		68	66
Total		107	103
Southern California Gas Company [Member] | Derivative Financial Instruments Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commodity contracts not subject to rate recovery, assets		1
Commodity contracts subject to rate recovery, assets		3	2
Total		4	2
Southern California Gas Company [Member] | Derivative Financial Instruments Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commodity contracts not subject to rate recovery, liabilities		0	0
Commodity contracts subject to rate recovery, liabilities		1	1
Total		1	1
Level 1 | Nuclear Decommisioning Trusts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nuclear decommissioning trusts - equity securities		623	619
Nuclear decommissioning trusts - Debt securities issued by the U.S. Treasury and other U.S. government corporations and agencies		62	47
Nuclear decommissioning trusts - Municipal bonds		0	0
Nuclear decommissioning trusts - Other securities		0	0
Nuclear decommissioning trusts - Total debt securities		62	47
Total nuclear decommissioning trusts	[1]	685	666
Level 1 | Derivative Financial Instruments Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate and foreign exchange instruments		0	0
Commodity contracts not subject to rate recovery, assets		1	22
Commodity contracts subject to rate recovery, assets		0	0
Total		686	688
Level 1 | Derivative Financial Instruments Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate and foreign exchange instruments		0	0
Commodity contracts not subject to rate recovery, liabilities		3	5
Commodity contracts subject to rate recovery, liabilities		0	0
Total		3	5
Level 1 | San Diego Gas and Electric Company [Member] | Nuclear Decommisioning Trusts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nuclear decommissioning trusts - equity securities		623	619
Nuclear decommissioning trusts - Debt securities issued by the U.S. Treasury and other U.S. government corporations and agencies		62	47
Nuclear decommissioning trusts - Municipal bonds		0	0
Nuclear decommissioning trusts - Other securities		0	0
Nuclear decommissioning trusts - Total debt securities		62	47
Total nuclear decommissioning trusts	[1]	685	666
Level 1 | San Diego Gas and Electric Company [Member] | Derivative Financial Instruments Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commodity contracts not subject to rate recovery, assets		0	0
Commodity contracts subject to rate recovery, assets		0	0
Total		685	666
Level 1 | San Diego Gas and Electric Company [Member] | Derivative Financial Instruments Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate instruments		0	0
Commodity contracts not subject to rate recovery, liabilities		1	1
Commodity contracts subject to rate recovery, liabilities		0	0
Total		1	1
Level 1 | Southern California Gas Company [Member] | Derivative Financial Instruments Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commodity contracts not subject to rate recovery, assets		0
Commodity contracts subject to rate recovery, assets		0	0
Total		0	0
Level 1 | Southern California Gas Company [Member] | Derivative Financial Instruments Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commodity contracts not subject to rate recovery, liabilities		1	1
Commodity contracts subject to rate recovery, liabilities		0	0
Total		1	1
Level 2 | Nuclear Decommisioning Trusts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nuclear decommissioning trusts - equity securities		0	0
Nuclear decommissioning trusts - Debt securities issued by the U.S. Treasury and other U.S. government corporations and agencies		43	44
Nuclear decommissioning trusts - Municipal bonds		156	156
Nuclear decommissioning trusts - Other securities		190	182
Nuclear decommissioning trusts - Total debt securities		389	382
Total nuclear decommissioning trusts	[1]	389	382
Level 2 | Derivative Financial Instruments Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate and foreign exchange instruments		8	5
Commodity contracts not subject to rate recovery, assets		19	16
Commodity contracts subject to rate recovery, assets		1	1
Total		417	404
Level 2 | Derivative Financial Instruments Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate and foreign exchange instruments		181	171
Commodity contracts not subject to rate recovery, liabilities		6	3
Commodity contracts subject to rate recovery, liabilities		67	68
Total		254	242
Level 2 | San Diego Gas and Electric Company [Member] | Nuclear Decommisioning Trusts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nuclear decommissioning trusts - equity securities		0	0
Nuclear decommissioning trusts - Debt securities issued by the U.S. Treasury and other U.S. government corporations and agencies		43	44
Nuclear decommissioning trusts - Municipal bonds		156	156
Nuclear decommissioning trusts - Other securities		190	182
Nuclear decommissioning trusts - Total debt securities		389	382
Total nuclear decommissioning trusts	[1]	389	382
Level 2 | San Diego Gas and Electric Company [Member] | Derivative Financial Instruments Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commodity contracts not subject to rate recovery, assets		0	0
Commodity contracts subject to rate recovery, assets		0	0
Total		389	382
Level 2 | San Diego Gas and Electric Company [Member] | Derivative Financial Instruments Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate instruments		39	37
Commodity contracts not subject to rate recovery, liabilities		0	0
Commodity contracts subject to rate recovery, liabilities		66	67
Total		105	104
Level 2 | Southern California Gas Company [Member] | Derivative Financial Instruments Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commodity contracts not subject to rate recovery, assets		0
Commodity contracts subject to rate recovery, assets		1	1
Total		1	1
Level 2 | Southern California Gas Company [Member] | Derivative Financial Instruments Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commodity contracts not subject to rate recovery, liabilities		0	0
Commodity contracts subject to rate recovery, liabilities		1	1
Total		1	1
Level 3 | Nuclear Decommisioning Trusts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nuclear decommissioning trusts - equity securities		0	0
Nuclear decommissioning trusts - Debt securities issued by the U.S. Treasury and other U.S. government corporations and agencies		0	0
Nuclear decommissioning trusts - Municipal bonds		0	0
Nuclear decommissioning trusts - Other securities		0	0
Nuclear decommissioning trusts - Total debt securities		0	0
Total nuclear decommissioning trusts	[1]	0	0
Level 3 | Derivative Financial Instruments Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate and foreign exchange instruments		0	0
Commodity contracts not subject to rate recovery, assets		0	0
Commodity contracts subject to rate recovery, assets		68	72
Total		68	72
Level 3 | Derivative Financial Instruments Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate and foreign exchange instruments		0	0
Commodity contracts not subject to rate recovery, liabilities		0	0
Commodity contracts subject to rate recovery, liabilities		57	53
Total		57	53
Level 3 | San Diego Gas and Electric Company [Member] | Nuclear Decommisioning Trusts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nuclear decommissioning trusts - equity securities		0	0
Nuclear decommissioning trusts - Debt securities issued by the U.S. Treasury and other U.S. government corporations and agencies		0	0
Nuclear decommissioning trusts - Municipal bonds		0	0
Nuclear decommissioning trusts - Other securities		0	0
Nuclear decommissioning trusts - Total debt securities		0	0
Total nuclear decommissioning trusts	[1]	0	0
Level 3 | San Diego Gas and Electric Company [Member] | Derivative Financial Instruments Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commodity contracts not subject to rate recovery, assets		0	0
Commodity contracts subject to rate recovery, assets		68	72
Total		68	72
Level 3 | San Diego Gas and Electric Company [Member] | Derivative Financial Instruments Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate instruments		0	0
Commodity contracts not subject to rate recovery, liabilities		0	0
Commodity contracts subject to rate recovery, liabilities		57	53
Total		57	53
Level 3 | Southern California Gas Company [Member] | Derivative Financial Instruments Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commodity contracts not subject to rate recovery, assets		0
Commodity contracts subject to rate recovery, assets		0	0
Total		0	0
Level 3 | Southern California Gas Company [Member] | Derivative Financial Instruments Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commodity contracts not subject to rate recovery, liabilities		0	0
Commodity contracts subject to rate recovery, liabilities		0	0
Total		0	0
Netting | Nuclear Decommisioning Trusts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nuclear decommissioning trusts - equity securities	[2]	0	0
Nuclear decommissioning trusts - Debt securities issued by the U.S. Treasury and other U.S. government corporations and agencies	[2]	0	0
Nuclear decommissioning trusts - Municipal bonds	[2]	0	0
Nuclear decommissioning trusts - Other securities	[2]	0	0
Nuclear decommissioning trusts - Total debt securities	[2]	0	0
Total nuclear decommissioning trusts	[1],[2]	0	0
Netting | Derivative Financial Instruments Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate and foreign exchange instruments	[2]	0	0
Commodity contracts not subject to rate recovery, assets	[2]	20	(4)
Commodity contracts subject to rate recovery, assets	[2]	32	28
Total	[2]	52	24
Netting | Derivative Financial Instruments Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate and foreign exchange instruments	[2]	0	0
Commodity contracts not subject to rate recovery, liabilities	[2]	(7)	(4)
Commodity contracts subject to rate recovery, liabilities	[2]	(55)	(54)
Total	[2]	(62)	(58)
Netting | San Diego Gas and Electric Company [Member] | Nuclear Decommisioning Trusts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Nuclear decommissioning trusts - equity securities	[2]	0	0
Nuclear decommissioning trusts - Debt securities issued by the U.S. Treasury and other U.S. government corporations and agencies	[2]	0	0
Nuclear decommissioning trusts - Municipal bonds	[2]	0	0
Nuclear decommissioning trusts - Other securities	[2]	0	0
Nuclear decommissioning trusts - Total debt securities	[2]	0	0
Total nuclear decommissioning trusts	[1],[2]	0	0
Netting | San Diego Gas and Electric Company [Member] | Derivative Financial Instruments Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commodity contracts not subject to rate recovery, assets	[2]	2	1
Commodity contracts subject to rate recovery, assets	[2]	30	27
Total	[2]	32	28
Netting | San Diego Gas and Electric Company [Member] | Derivative Financial Instruments Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate instruments	[2]	0	0
Commodity contracts not subject to rate recovery, liabilities	[2]	(1)	(1)
Commodity contracts subject to rate recovery, liabilities	[2]	(55)	(54)
Total	[2]	(56)	(55)
Netting | Southern California Gas Company [Member] | Derivative Financial Instruments Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commodity contracts not subject to rate recovery, assets	[2]	1
Commodity contracts subject to rate recovery, assets	[2]	2	1
Total	[2]	3	1
Netting | Southern California Gas Company [Member] | Derivative Financial Instruments Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commodity contracts not subject to rate recovery, liabilities	[2]	(1)	(1)
Commodity contracts subject to rate recovery, liabilities	[2]	0	0
Total	[2]	$ (1)	$ (1)

[1] Excludes cash balances and cash equivalents.

[2] Includes the effect of the contractual ability to settle contracts under master netting agreements and with cash collateral, as well as cash collateral not offset.