OTHER FINANCIAL DATA - OTHER INCOME (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016		Jun. 30, 2017	Jun. 30, 2016
Other Income [Line Items]
Allowance for equity funds used during construction	$ 40	$ 30		$ 112	$ 57
Investment gains	14	10		30	20
Gains (losses) on interest rate and foreign exchange instruments, net	31	(15)		94	(12)
Foreign currency transaction gains (losses)	7	(5)		17	(7)
Electrical infrastructure relocation income	0	2		0	3
Regulatory Interest, net	0	1		2	3
Sundry, net	(1)	0		5	8
Total	91	23	[1]	260	72	[1]
San Diego Gas and Electric Company [Member]
Other Income [Line Items]
Allowance for equity funds used during construction	16	13		31	24
Regulatory Interest, net	0	1		2	3
Sundry, net	(1)	(1)		0	0
Total	15	13		33	27	[1]
Southern California Gas Company [Member]
Other Income [Line Items]
Allowance for equity funds used during construction	11	10		22	20
Sundry, net	(2)	(4)		(2)	(4)
Total	$ 9	$ 6		$ 20	$ 16	[1]

[1] As adjusted for the adoption of ASU 2016-09 as of January 1, 2016.