COMMITMENTS AND CONTINGENCIES - LESSEE MATURITY ANALYSIS OF LIABILITIES (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Operating leases
2021	$ 73
2022	64
2023	55
2024	51
2025	40
Thereafter	415
Total undiscounted lease payments	698
Less: imputed interest	(239)
Total lease liabilities	459	$ 497
Less: current lease liabilities	(52)	(52)
Long-term lease liabilities	407	445
Finance leases
2021	206
2022	203
2023	203
2024	198
2025	193
Thereafter	2,465
Total undiscounted lease payments	3,468
Less: imputed interest	(2,138)
Total finance leases	1,330	1,289
Less: current lease liabilities	(36)	(26)
Long-term lease liabilities	1,294	1,263
San Diego Gas and Electric Company [Member]
Operating leases
2021	30
2022	22
2023	17
2024	15
2025	5
Thereafter	22
Total undiscounted lease payments	111
Less: imputed interest	(11)
Total lease liabilities	100	129
Less: current lease liabilities	(27)	(27)
Long-term lease liabilities	73	102
Finance leases
2021	194
2022	194
2023	194
2024	189
2025	185
Thereafter	2,453
Total undiscounted lease payments	3,409
Less: imputed interest	(2,133)
Total finance leases	1,276	1,270
Less: current lease liabilities	(26)	(20)
Long-term lease liabilities	1,250	1,250
Southern California Gas Company [Member]
Operating leases
2021	19
2022	17
2023	13
2024	11
2025	9
Thereafter	8
Total undiscounted lease payments	77
Less: imputed interest	(3)
Total lease liabilities	74	93
Less: current lease liabilities	(18)	(18)
Long-term lease liabilities	56	75
Finance leases
2021	12
2022	9
2023	9
2024	9
2025	8
Thereafter	12
Total undiscounted lease payments	59
Less: imputed interest	(5)
Total finance leases	54	19
Less: current lease liabilities	(10)	(6)
Long-term lease liabilities	$ 44	$ 13