COMMITMENTS AND CONTINGENCIES - LESSEE MATURITY OF LEASE LIABILITIES (Details) $ in Millions	Sep. 30, 2019 USD ($)
Operating leases
2019 (excluding first nine months of 2019)	$ 17
2020	72
2021	69
2022	62
2023	53
Thereafter	494
Total undiscounted lease payments	767
Less: imputed interest	(273)
Total operating lease liabilities	494
Less: current lease liabilities	(47)
Long-term lease liabilities	447
Finance leases
2019 (excluding first nine months of 2019)	50
2020	195
2021	192
2022	191
2023	191
Thereafter	2,811
Total undiscounted lease payments	3,630
Less: imputed interest	(2,345)
Total finance lease liabilities	1,285
Less: current lease liabilities	(24)
Long-term lease liabilities	1,261
Southern California Gas Company [Member]
Operating leases
2019 (excluding first nine months of 2019)	6
2020	23
2021	20
2022	17
2023	13
Thereafter	30
Total undiscounted lease payments	109
Less: imputed interest	(11)
Total operating lease liabilities	98
Less: current lease liabilities	(19)
Long-term lease liabilities	79
Finance leases
2019 (excluding first nine months of 2019)	2
2020	4
2021	2
2022	2
2023	2
Thereafter	4
Total undiscounted lease payments	16
Less: imputed interest	(1)
Total finance lease liabilities	15
Less: current lease liabilities	(5)
Long-term lease liabilities	10
San Diego Gas and Electric Company [Member]
Operating leases
2019 (excluding first nine months of 2019)	7
2020	26
2021	26
2022	22
2023	17
Thereafter	43
Total undiscounted lease payments	141
Less: imputed interest	(17)
Total operating lease liabilities	124
Less: current lease liabilities	(22)
Long-term lease liabilities	102
Finance leases
2019 (excluding first nine months of 2019)	48
2020	191
2021	190
2022	189
2023	189
Thereafter	2,807
Total undiscounted lease payments	3,614
Less: imputed interest	(2,344)
Total finance lease liabilities	1,270
Less: current lease liabilities	(19)
Long-term lease liabilities	$ 1,251