GENERAL INFORMATION AND OTHER FINANCIAL DATA - PENSION AND OTHER POSTRETIREMENT BENEFITS (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Pension
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 25	$ 27	$ 82	$ 110
Interest cost	39	29	118	88
Expected return on assets	(42)	(46)	(127)	(137)
Amortization of:
Prior service cost (credit)	2	3	4	8
Actuarial loss (gain)	3	8	7	19
Net periodic benefit cost (credit)	27	21	84	88
Regulatory adjustments	30	87	88	84
Total expense (income) recognized	57	108	172	172
Pension | San Diego Gas and Electric Company
Defined Benefit Plan Disclosure [Line Items]
Service cost	8	8	24	28
Interest cost	10	7	30	20
Expected return on assets	(9)	(13)	(29)	(35)
Amortization of:
Actuarial loss (gain)	2	0	4	1
Net periodic benefit cost (credit)	11	2	29	14
Regulatory adjustments	3	24	11	26
Total expense (income) recognized	14	26	40	40
Pension | Southern California Gas Company
Defined Benefit Plan Disclosure [Line Items]
Service cost	15	16	49	72
Interest cost	24	20	75	61
Expected return on assets	(29)	(30)	(89)	(94)
Amortization of:
Prior service cost (credit)	1	2	3	6
Actuarial loss (gain)	1	6	1	14
Net periodic benefit cost (credit)	12	14	39	59
Regulatory adjustments	27	63	77	58
Total expense (income) recognized	39	77	116	117
PBOP
Defined Benefit Plan Disclosure [Line Items]
Service cost	3	4	10	17
Interest cost	9	7	28	21
Expected return on assets	(17)	(16)	(52)	(48)
Amortization of:
Prior service cost (credit)	(1)	(1)	(2)	(2)
Actuarial loss (gain)	(5)	(4)	(17)	(11)
Net periodic benefit cost (credit)	(11)	(10)	(33)	(23)
Regulatory adjustments	10	10	32	23
Total expense (income) recognized	(1)	0	(1)	0
PBOP | San Diego Gas and Electric Company
Defined Benefit Plan Disclosure [Line Items]
Service cost	1	1	2	4
Interest cost	2	1	6	4
Expected return on assets	(2)	(2)	(6)	(7)
Amortization of:
Actuarial loss (gain)	0	(1)	(1)	(2)
Net periodic benefit cost (credit)	1	(1)	1	(1)
Regulatory adjustments	(1)	1	(1)	1
Total expense (income) recognized	0	0	0	0
PBOP | Southern California Gas Company
Defined Benefit Plan Disclosure [Line Items]
Service cost	2	3	7	13
Interest cost	7	5	21	16
Expected return on assets	(14)	(13)	(44)	(40)
Amortization of:
Prior service cost (credit)	(1)	(1)	(2)	(2)
Actuarial loss (gain)	(5)	(3)	(15)	(9)
Net periodic benefit cost (credit)	(11)	(9)	(33)	(22)
Regulatory adjustments	11	9	33	22
Total expense (income) recognized	$ 0	$ 0	$ 0	$ 0