COMMITMENTS AND CONTINGENCIES - LESSEE CASH FLOW INFORMATION (Details) - USD ($)	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Lessee, Lease, Description [Line Items]
Cash paid for operating leases	$ 59,000,000
Cash paid for finance leases - operating	87,000,000
Cash paid for finance leases - financing	11,000,000
Increase in operating lease obligations for right-of-use assets	559,000,000
Increase in finance lease obligations for investment in PP&E	16,000,000	$ 7,000,000
Southern California Gas Company [Member]
Lessee, Lease, Description [Line Items]
Cash paid for operating leases	14,000,000
Cash paid for finance leases - operating	0
Cash paid for finance leases - financing	2,000,000
Increase in operating lease obligations for right-of-use assets	117,000,000
Increase in finance lease obligations for investment in PP&E	9,000,000	7,000,000
San Diego Gas and Electric Company [Member]
Lessee, Lease, Description [Line Items]
Cash paid for operating leases	17,000,000
Cash paid for finance leases - operating	87,000,000
Cash paid for finance leases - financing	9,000,000
Increase in operating lease obligations for right-of-use assets	146,000,000
Increase in finance lease obligations for investment in PP&E	$ 7,000,000	$ 0