COMMITMENTS AND CONTINGENCIES - LESSEE BALANCE SHEET INFORMATION (Details) $ in Millions	Sep. 30, 2019 USD ($)
Operating leases:
Operating Lease, Right-of-Use Asset	$ 595
Finance leases:
Property, plant and equipment	1,342
Accumulated depreciation	(57)
Property, plant and equipment, net	1,285
Total right-of-use assets	1,880
Operating leases:
Other current liabilities	47
Long-term lease liabilities	447
Total operating lease liabilities	494
Finance Lease, Finance Leases [Abstract]
Current portion of long-term debt and finance leases	24
Long-term debt and finance leases	1,261
Total finance lease liabilities	1,285
Total lease liabilities	$ 1,779
Weighted-average remaining lease term (in years):
Operating leases, Weighted-average remaining lease term (in years)	14 years
Finance leases, Weighted-average remaining lease term (in years)	20 years
Weighted-average discount rate:
Operating leases, Weighted-average discount rate	6.02%
Finance leases, Weighted-average discount rate	14.81%
San Diego Gas and Electric Company [Member]
Operating leases:
Operating Lease, Right-of-Use Asset	$ 126
Finance leases:
Property, plant and equipment	1,322
Accumulated depreciation	(52)
Property, plant and equipment, net	1,270
Total right-of-use assets	1,396
Operating leases:
Other current liabilities	22
Long-term lease liabilities	102
Total operating lease liabilities	124
Finance Lease, Finance Leases [Abstract]
Current portion of long-term debt and finance leases	19
Long-term debt and finance leases	1,251
Total finance lease liabilities	1,270
Total lease liabilities	$ 1,394
Weighted-average remaining lease term (in years):
Operating leases, Weighted-average remaining lease term (in years)	7 years
Finance leases, Weighted-average remaining lease term (in years)	20 years
Weighted-average discount rate:
Operating leases, Weighted-average discount rate	3.69%
Finance leases, Weighted-average discount rate	14.86%
Southern California Gas Company [Member]
Operating leases:
Operating Lease, Right-of-Use Asset	$ 99
Finance leases:
Property, plant and equipment	20
Accumulated depreciation	(5)
Property, plant and equipment, net	15
Total right-of-use assets	114
Operating leases:
Other current liabilities	19
Long-term lease liabilities	79
Total operating lease liabilities	98
Finance Lease, Finance Leases [Abstract]
Current portion of long-term debt and finance leases	5
Long-term debt and finance leases	10
Total finance lease liabilities	15
Total lease liabilities	$ 113
Weighted-average remaining lease term (in years):
Operating leases, Weighted-average remaining lease term (in years)	6 years
Finance leases, Weighted-average remaining lease term (in years)	6 years
Weighted-average discount rate:
Operating leases, Weighted-average discount rate	3.75%
Finance leases, Weighted-average discount rate	3.41%