OTHER FINANCIAL DATA - CHANGES IN ACCUMULATED OTHER COMPREHENSIVE INCOME (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017		Jun. 30, 2016
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
AOCI, beginning balance	$ (696,000,000)	$ (821,000,000)	$ (748,000,000)	[1]	$ (806,000,000)
OCI before reclassifications	(23,000,000)	(37,000,000)	21,000,000		(51,000,000)
Amounts reclassified from accumulated other comprehensive income	1,000,000	6,000,000	9,000,000		5,000,000
Net OCI	(22,000,000)	(31,000,000)	30,000,000		(46,000,000)
AOCI, ending balance	(718,000,000)	(852,000,000)	(718,000,000)		(852,000,000)
Foreign currency translation adjustments [Member]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
AOCI, beginning balance	(481,000,000)	(514,000,000)	(527,000,000)		(582,000,000)
OCI before reclassifications	3,000,000	11,000,000	49,000,000		79,000,000
Amounts reclassified from accumulated other comprehensive income	0	0	0		0
Net OCI	3,000,000	11,000,000	49,000,000		79,000,000
AOCI, ending balance	(478,000,000)	(503,000,000)	(478,000,000)		(503,000,000)
Financial instruments [Member]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
AOCI, beginning balance	(121,000,000)	(221,000,000)	(125,000,000)		(137,000,000)
OCI before reclassifications	(26,000,000)	(48,000,000)	(28,000,000)		(130,000,000)
Amounts reclassified from accumulated other comprehensive income	0	5,000,000	6,000,000		3,000,000
Net OCI	(26,000,000)	(43,000,000)	(22,000,000)		(127,000,000)
AOCI, ending balance	(147,000,000)	(264,000,000)	(147,000,000)		(264,000,000)
Pension and other postretirement benefits [Member]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
AOCI, beginning balance	(94,000,000)	(86,000,000)	(96,000,000)		(87,000,000)
OCI before reclassifications	0	0	0		0
Amounts reclassified from accumulated other comprehensive income	1,000,000	1,000,000	3,000,000		2,000,000
Net OCI	1,000,000	1,000,000	3,000,000		2,000,000
AOCI, ending balance	(93,000,000)	(85,000,000)	(93,000,000)		(85,000,000)
San Diego Gas and Electric Company [Member]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
AOCI, beginning balance	(8,000,000)	(8,000,000)	(8,000,000)	[1]	(8,000,000)
Amounts reclassified from accumulated other comprehensive income	0	0	0		0
AOCI, ending balance	(8,000,000)	(8,000,000)	(8,000,000)		(8,000,000)
San Diego Gas and Electric Company [Member] | Pension and other postretirement benefits [Member]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
AOCI, beginning balance	(8,000,000)	(8,000,000)	(8,000,000)		(8,000,000)
AOCI, ending balance	(8,000,000)	(8,000,000)	(8,000,000)		(8,000,000)
Southern California Gas Company [Member]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
AOCI, beginning balance	(22,000,000)	(19,000,000)	(22,000,000)	[1]	(19,000,000)
Amounts reclassified from accumulated other comprehensive income	1,000,000	0	1,000,000		0
Net OCI	1,000,000		1,000,000
AOCI, ending balance	(21,000,000)	(19,000,000)	(21,000,000)		(19,000,000)
Southern California Gas Company [Member] | Financial instruments [Member]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
AOCI, beginning balance	(13,000,000)	(14,000,000)	(13,000,000)		(14,000,000)
Amounts reclassified from accumulated other comprehensive income	0		0
Net OCI	0		0
AOCI, ending balance	(13,000,000)	(14,000,000)	(13,000,000)		(14,000,000)
Southern California Gas Company [Member] | Pension and other postretirement benefits [Member]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
AOCI, beginning balance	(9,000,000)	(5,000,000)	(9,000,000)		(5,000,000)
Amounts reclassified from accumulated other comprehensive income	1,000,000		1,000,000
Net OCI	1,000,000		1,000,000
AOCI, ending balance	$ (8,000,000)	$ (5,000,000)	$ (8,000,000)		$ (5,000,000)

[1] Derived from audited financial statements.