COMMITMENTS AND CONTINGENCIES - LEASES BALANCE SHEET INFORMATION (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Lessee, Lease, Description [Line Items]
Right-of-use assets	$ 543	$ 591
Finance leases, property plant and equipment	1,429	1,353
Finance leases, accumulated depreciation	(99)	(64)
Finance leases, property plant and equipment, net	1,330	1,289
Total right-of-use assets	$ 1,873	$ 1,880
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	us-gaap:OtherLiabilitiesCurrent	us-gaap:OtherLiabilitiesCurrent
Operating lease, other current liabilities	$ 52	$ 52
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	us-gaap:DeferredCreditsAndOtherLiabilities	us-gaap:DeferredCreditsAndOtherLiabilities
Operating lease, deferred credits and other	$ 407	$ 445
Total lease liabilities	459	497
Finance lease, current portion of long-term debt and finance leases	36	26
Long-term lease liabilities	1,294	1,263
Total finance leases	1,330	1,289
Lease liabilities	$ 1,789	$ 1,786
Operating lease, weighted-average remaining lease term	13 years	13 years
Finance lease, weighted-average remaining lease term	18 years	19 years
Operating lease, weighted-average discount rate (as a percent)	5.81%	6.01%
Finance lease, weighted-average discount rate (as a percent)	14.45%	14.76%
SDG&E [Member]
Lessee, Lease, Description [Line Items]
Variable payments, due in 2021	$ 297
Variable payments, due in 2022	297
Variable payments, due in 2023	296
Variable payments, due in 2024	297
Variable payments, due in 2025	296
Variable payments, due thereafter	3,069
San Diego Gas and Electric Company [Member]
Lessee, Lease, Description [Line Items]
Right-of-use assets	102	$ 130
Finance leases, property plant and equipment	1,356	1,326
Finance leases, accumulated depreciation	(80)	(57)
Finance leases, property plant and equipment, net	1,276	1,269
Total right-of-use assets	1,378	1,399
Operating lease, other current liabilities	27	27
Operating lease, deferred credits and other	73	102
Total lease liabilities	100	129
Finance lease, current portion of long-term debt and finance leases	26	20
Long-term lease liabilities	1,250	1,250
Total finance leases	1,276	1,270
Lease liabilities	$ 1,376	$ 1,399
Operating lease, weighted-average remaining lease term	6 years	6 years
Finance lease, weighted-average remaining lease term	19 years	20 years
Operating lease, weighted-average discount rate (as a percent)	3.62%	3.55%
Finance lease, weighted-average discount rate (as a percent)	14.65%	14.83%
Southern California Gas Company [Member]
Lessee, Lease, Description [Line Items]
Right-of-use assets	$ 74	$ 94
Finance leases, property plant and equipment	73	27
Finance leases, accumulated depreciation	(19)	(7)
Finance leases, property plant and equipment, net	54	20
Total right-of-use assets	128	114
Operating lease, other current liabilities	18	18
Operating lease, deferred credits and other	56	75
Total lease liabilities	74	93
Finance lease, current portion of long-term debt and finance leases	10	6
Long-term lease liabilities	44	13
Total finance leases	54	19
Lease liabilities	$ 128	$ 112
Operating lease, weighted-average remaining lease term	5 years	6 years
Finance lease, weighted-average remaining lease term	7 years	6 years
Operating lease, weighted-average discount rate (as a percent)	2.03%	3.73%
Finance lease, weighted-average discount rate (as a percent)	2.83%	3.23%
Maximum [Member]
Lessee, Lease, Description [Line Items]
Operating lease renewal period	20 years
Annual increase in rent, percent	4.00%
Minimum [Member]
Lessee, Lease, Description [Line Items]
Operating lease termination period	1 year
Annual increase in rent, percent	2.00%