COMMITMENTS AND CONTINGENCIES - LESSEE BALANCE SHEET INFORMATION (Details)	Mar. 31, 2019 USD ($)
Lessee, Lease, Description [Line Items]
Right-of-use assets	$ 612,000,000
Property, plant and equipment	1,322,000,000
Accumulated depreciation	(45,000,000)
Property, plant and equipment, net	1,277,000,000
Total right-of-use assets	1,889,000,000
Other current liabilities	52,000,000
Deferred credits and other	455,000,000
Total lease liabilities	507,000,000
Current portion of long-term debt and finance leases	21,000,000
Long-term debt and finance leases	1,256,000,000
Total lease liabilities	1,277,000,000
Total lease liabilities	$ 1,784,000,000
Operating leases, Weighted-average remaining lease term (in years)	14 years
Finance leases, Weighted-average remaining lease term (in years)	20 years
Operating leases, Weighted-average discount rate	5.87%
Finance leases, Weighted-average discount rate	14.91%
San Diego Gas and Electric Company [Member]
Lessee, Lease, Description [Line Items]
Right-of-use assets	$ 135,000,000
Property, plant and equipment	1,315,000,000
Accumulated depreciation	(43,000,000)
Property, plant and equipment, net	1,272,000,000
Total right-of-use assets	1,407,000,000
Other current liabilities	24,000,000
Deferred credits and other	110,000,000
Total lease liabilities	134,000,000
Current portion of long-term debt and finance leases	18,000,000
Long-term debt and finance leases	1,254,000,000
Total lease liabilities	1,272,000,000
Total lease liabilities	$ 1,406,000,000
Operating leases, Weighted-average remaining lease term (in years)	7 years
Finance leases, Weighted-average remaining lease term (in years)	20 years
Operating leases, Weighted-average discount rate	3.69%
Finance leases, Weighted-average discount rate	14.92%
Southern California Gas Company [Member]
Lessee, Lease, Description [Line Items]
Right-of-use assets	$ 110,000,000
Property, plant and equipment	7,000,000
Accumulated depreciation	(2,000,000)
Property, plant and equipment, net	5,000,000
Total right-of-use assets	115,000,000
Other current liabilities	22,000,000
Deferred credits and other	88,000,000
Total lease liabilities	110,000,000
Current portion of long-term debt and finance leases	3,000,000
Long-term debt and finance leases	2,000,000
Total lease liabilities	5,000,000
Total lease liabilities	$ 115,000,000
Operating leases, Weighted-average remaining lease term (in years)	6 years
Finance leases, Weighted-average remaining lease term (in years)	3 years
Operating leases, Weighted-average discount rate	3.76%
Finance leases, Weighted-average discount rate	3.94%