FAIR VALUE MEASUREMENTS - RECURRING FAIR VALUE MEASURES (Details) - USD ($) $ in Millions		Jun. 30, 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		$ 632	$ 619
Nuclear decommissioning trusts - Debt securities issued by the U.S. Treasury and other U.S. government corporations and agencies		104	91
Nuclear decommissioning trusts - Municipal bonds		163	156
Nuclear decommissioning trusts - Other securities		192	182
Nuclear decommissioning trusts - Total debt securities		459	429
Total nuclear decommissioning trusts	[1]	1,091	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		1	5
Commodity contracts not subject to rate recovery, assets		32	34
Commodity contracts subject to rate recovery, assets		91	101
Total		1,215	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		211	171
Commodity contracts not subject to rate recovery, liabilities		6	4
Commodity contracts subject to rate recovery, liabilities		49	67
Total		266	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		632	619
Nuclear decommissioning trusts - Debt securities issued by the U.S. Treasury and other U.S. government corporations and agencies		104	91
Nuclear decommissioning trusts - Municipal bonds		163	156
Nuclear decommissioning trusts - Other securities		192	182
Nuclear decommissioning trusts - Total debt securities		459	429
Total nuclear decommissioning trusts	[1]	1,091	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			1
Commodity contracts subject to rate recovery, assets		89	99
Total		1,180	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		37	37
Commodity contracts not subject to rate recovery, liabilities			0
Commodity contracts subject to rate recovery, liabilities		48	66
Total		85	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		2	2
Total		3	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		632	619
Nuclear decommissioning trusts - Debt securities issued by the U.S. Treasury and other U.S. government corporations and agencies		52	47
Nuclear decommissioning trusts - Municipal bonds		0	0
Nuclear decommissioning trusts - Other securities		0	0
Nuclear decommissioning trusts - Total debt securities		52	47
Total nuclear decommissioning trusts	[1]	684	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		685	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		32	5
Commodity contracts subject to rate recovery, liabilities		1	0
Total		33	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		632	619
Nuclear decommissioning trusts - Debt securities issued by the U.S. Treasury and other U.S. government corporations and agencies		52	47
Nuclear decommissioning trusts - Municipal bonds		0	0
Nuclear decommissioning trusts - Other securities		0	0
Nuclear decommissioning trusts - Total debt securities		52	47
Total nuclear decommissioning trusts	[1]	684	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
Commodity contracts subject to rate recovery, assets		0	0
Total		684	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
Commodity contracts subject to rate recovery, liabilities		0	0
Total		0	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		1	0
Total		2	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		52	44
Nuclear decommissioning trusts - Municipal bonds		163	156
Nuclear decommissioning trusts - Other securities		192	182
Nuclear decommissioning trusts - Total debt securities		407	382
Total nuclear decommissioning trusts	[1]	407	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		1	5
Commodity contracts not subject to rate recovery, assets		17	16
Commodity contracts subject to rate recovery, assets		1	1
Total		426	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		211	171
Commodity contracts not subject to rate recovery, liabilities		5	3
Commodity contracts subject to rate recovery, liabilities		37	68
Total		253	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		52	44
Nuclear decommissioning trusts - Municipal bonds		163	156
Nuclear decommissioning trusts - Other securities		192	182
Nuclear decommissioning trusts - Total debt securities		407	382
Total nuclear decommissioning trusts	[1]	407	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
Commodity contracts subject to rate recovery, assets		0	0
Total		407	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		37	37
Commodity contracts not subject to rate recovery, liabilities			0
Commodity contracts subject to rate recovery, liabilities		36	67
Total		73	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		63	72
Total		63	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		39	53
Total		39	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
Commodity contracts subject to rate recovery, assets		63	72
Total		63	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
Commodity contracts subject to rate recovery, liabilities		39	53
Total		39	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]	14	(4)
Commodity contracts subject to rate recovery, assets	[2]	27	28
Total	[2]	41	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]	31	4
Commodity contracts subject to rate recovery, liabilities	[2]	28	54
Total	[2]	59	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]		1
Commodity contracts subject to rate recovery, assets	[2]	26	27
Total	[2]	26	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
Commodity contracts subject to rate recovery, liabilities	[2]	27	54
Total	[2]	27	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]	1	1
Total	[2]	2	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]	1	0
Total	[2]	$ 2	$ 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.