GENERAL INFORMATION AND OTHER FINANCIAL DATA - PENSION AND OTHER POSTRETIREMENT BENEFITS (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Pension
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 28	$ 41
Interest cost	40	30
Expected return on assets	(43)	(46)
Amortization of:
Prior service cost (credit)	1	3
Actuarial loss (gain)	2	6
Net periodic benefit cost (credit)	28	34
Regulatory adjustments	29	(27)
Total expense recognized	57	7
Pension | San Diego Gas and Electric Company
Defined Benefit Plan Disclosure [Line Items]
Service cost	8	10
Interest cost	10	7
Expected return on assets	(10)	(11)
Amortization of:
Actuarial loss (gain)	1	0
Net periodic benefit cost (credit)	9	6
Regulatory adjustments	4	(5)
Total expense recognized	13	1
Pension | Southern California Gas Company
Defined Benefit Plan Disclosure [Line Items]
Service cost	17	28
Interest cost	25	20
Expected return on assets	(29)	(31)
Amortization of:
Prior service cost (credit)	1	2
Actuarial loss (gain)	0	4
Net periodic benefit cost (credit)	14	23
Regulatory adjustments	25	(22)
Total expense recognized	39	1
PBOP
Defined Benefit Plan Disclosure [Line Items]
Service cost	4	7
Interest cost	9	7
Expected return on assets	(17)	(16)
Amortization of:
Prior service cost (credit)	(1)	(1)
Actuarial loss (gain)	(6)	(4)
Net periodic benefit cost (credit)	(11)	(7)
Regulatory adjustments	11	7
Total expense recognized	0	0
PBOP | San Diego Gas and Electric Company
Defined Benefit Plan Disclosure [Line Items]
Service cost	1	2
Interest cost	2	1
Expected return on assets	(2)	(2)
Amortization of:
Actuarial loss (gain)	(1)	(1)
Net periodic benefit cost (credit)	0	0
Regulatory adjustments	0	0
Total expense recognized	0	0
PBOP | Southern California Gas Company
Defined Benefit Plan Disclosure [Line Items]
Service cost	3	5
Interest cost	7	5
Expected return on assets	(15)	(13)
Amortization of:
Prior service cost (credit)	(1)	(1)
Actuarial loss (gain)	(5)	(3)
Net periodic benefit cost (credit)	(11)	(7)
Regulatory adjustments	11	7
Total expense recognized	$ 0	$ 0