OTHER FINANCIAL DATA - CHANGES IN ACCUMULATED OTHER COMPREHENSIVE INCOME (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017		Mar. 31, 2016
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
AOCI, beginning balance	$ (748)	[1]	$ (806)
Other comprehensive income (loss), before reclassifications	44		(14)
Amounts reclassified from accumulated other comprehensive income	8		(1)
Total other comprehensive income (loss)	52		(15)
AOCI, ending balance	(696)		(821)
Foreign currency translation adjustments [Member]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
AOCI, beginning balance	(527)		(582)
Other comprehensive income (loss), before reclassifications	46		68
Amounts reclassified from accumulated other comprehensive income	0		0
Total other comprehensive income (loss)	46		68
AOCI, ending balance	(481)		(514)
Financial instruments [Member]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
AOCI, beginning balance	(125)		(137)
Other comprehensive income (loss), before reclassifications	(2)		(82)
Amounts reclassified from accumulated other comprehensive income	6		(2)
Total other comprehensive income (loss)	4		(84)
AOCI, ending balance	(121)		(221)
Pension and other postretirement benefits [Member]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
AOCI, beginning balance	(96)		(87)
Other comprehensive income (loss), before reclassifications	0		0
Amounts reclassified from accumulated other comprehensive income	2		1
Total other comprehensive income (loss)	2		1
AOCI, ending balance	(94)		(86)
San Diego Gas and Electric Company [Member]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
AOCI, beginning balance	(8)	[1]	(8)
Amounts reclassified from accumulated other comprehensive income	0		0
AOCI, ending balance	(8)		(8)
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)		(8)
AOCI, ending balance	(8)		(8)
Southern California Gas Company [Member]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
AOCI, beginning balance	(22)	[1]	(19)
AOCI, ending balance	(22)		(19)
Southern California Gas Company [Member] | Financial instruments [Member]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
AOCI, beginning balance	(13)		(14)
AOCI, ending balance	(13)		(14)
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)		(5)
AOCI, ending balance	$ (9)		$ (5)

[1] Derived from audited financial statements.