OTHER FINANCIAL DATA - CHANGES IN ACCUMULATED OTHER COMPREHENSIVE INCOME (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016		Sep. 30, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
AOCI, beginning balance	$ (852)	$ (596)	$ (806)	[1]	$ (497)
Other comprehensive income (loss), before reclassifications	(20)	(171)	(71)		(273)
Amounts reclassified from accumulated other comprehensive income	7	6	12		9
Total other comprehensive loss	(13)	(165)	(59)		(264)
AOCI, ending balance	(865)	(761)	(865)		(761)
Foreign currency translation adjustments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
AOCI, beginning balance	(503)	(427)	(582)		(322)
Other comprehensive income (loss), before reclassifications	(28)	(92)	51		(197)
Amounts reclassified from accumulated other comprehensive income	0	0	0		0
Total other comprehensive loss	(28)	(92)	51		(197)
AOCI, ending balance	(531)	(519)	(531)		(519)
Financial instruments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
AOCI, beginning balance	(264)	(86)	(137)		(90)
Other comprehensive income (loss), before reclassifications	8	(79)	(122)		(76)
Amounts reclassified from accumulated other comprehensive income	5	1	8		2
Total other comprehensive loss	13	(78)	(114)		(74)
AOCI, ending balance	(251)	(164)	(251)		(164)
Pension and other postretirement benefits [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
AOCI, beginning balance	(85)	(83)	(87)		(85)
Other comprehensive income (loss), before reclassifications	0	0	0		0
Amounts reclassified from accumulated other comprehensive income	2	5	4		7
Total other comprehensive loss	2	5	4		7
AOCI, ending balance	(83)	(78)	(83)		(78)
Southern California Gas Company [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
AOCI, beginning balance	(19)	(18)	(19)	[1]	(18)
Amounts reclassified from accumulated other comprehensive income	1	0	1		0
Total other comprehensive loss	1		1
AOCI, ending balance	(18)	(18)	(18)		(18)
Southern California Gas Company [Member] | Financial instruments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
AOCI, beginning balance	(14)	(14)	(14)		(14)
Amounts reclassified from accumulated other comprehensive income	1		1
Total other comprehensive loss	1		1
AOCI, ending balance	(13)	(14)	(13)		(14)
Southern California Gas Company [Member] | Pension and other postretirement benefits [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
AOCI, beginning balance	(5)	(4)	(5)		(4)
Amounts reclassified from accumulated other comprehensive income	0		0
Total other comprehensive loss	0		0
AOCI, ending balance	$ (5)	$ (4)	$ (5)		$ (4)

[1] Derived from audited financial statements.