GENERAL INFORMATION AND OTHER FINANCIAL DATA - PENSION AND OTHER POSTRETIREMENT BENEFITS (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Pension
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 29	$ 42	$ 57	$ 83
Interest cost	39	29	79	59
Expected return on assets	(42)	(45)	(85)	(91)
Amortization of:
Prior service cost (credit)	1	2	2	5
Actuarial loss (gain)	2	5	4	11
Net periodic benefit cost (credit)	29	33	57	67
Regulatory adjustments	29	24	58	(3)
Total expense recognized	58	57	115	64
Pension | San Diego Gas and Electric Company
Defined Benefit Plan Disclosure [Line Items]
Service cost	8	10	16	20
Interest cost	10	6	20	13
Expected return on assets	(10)	(11)	(20)	(22)
Amortization of:
Actuarial loss (gain)	1	1	2	1
Net periodic benefit cost (credit)	9	6	18	12
Regulatory adjustments	4	7	8	2
Total expense recognized	13	13	26	14
Pension | Southern California Gas Company
Defined Benefit Plan Disclosure [Line Items]
Service cost	17	28	34	56
Interest cost	26	21	51	41
Expected return on assets	(31)	(33)	(60)	(64)
Amortization of:
Prior service cost (credit)	1	2	2	4
Actuarial loss (gain)	0	4	0	8
Net periodic benefit cost (credit)	13	22	27	45
Regulatory adjustments	25	17	50	(5)
Total expense recognized	38	39	77	40
PBOP
Defined Benefit Plan Disclosure [Line Items]
Service cost	3	6	7	13
Interest cost	10	7	19	14
Expected return on assets	(18)	(16)	(35)	(32)
Amortization of:
Prior service cost (credit)	0	0	(1)	(1)
Actuarial loss (gain)	(6)	(3)	(12)	(7)
Net periodic benefit cost (credit)	(11)	(6)	(22)	(13)
Regulatory adjustments	11	6	22	13
Total expense recognized	0	0	0	0
PBOP | San Diego Gas and Electric Company
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	1	1	3
Interest cost	2	2	4	3
Expected return on assets	(2)	(3)	(4)	(5)
Amortization of:
Actuarial loss (gain)	0	0	(1)	(1)
Net periodic benefit cost (credit)	0	0	0	0
Regulatory adjustments	0	0	0	0
Total expense recognized	0	0	0	0
PBOP | Southern California Gas Company
Defined Benefit Plan Disclosure [Line Items]
Service cost	2	5	5	10
Interest cost	7	6	14	11
Expected return on assets	(15)	(14)	(30)	(27)
Amortization of:
Prior service cost (credit)	0	0	(1)	(1)
Actuarial loss (gain)	(5)	(3)	(10)	(6)
Net periodic benefit cost (credit)	(11)	(6)	(22)	(13)
Regulatory adjustments	11	6	22	13
Total expense recognized	$ 0	$ 0	$ 0	$ 0