COMMITMENTS AND CONTINGENCIES - LESSEE CASH FLOW INFORMATION (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Lessee, Lease, Description [Line Items]
Increase in operating lease obligations for right-of-use assets	$ 19	$ 552
Increase in finance lease obligations for investment in PP&E	20	7
Aggregate maximum lease limit	167
Southern California Gas Company [Member]
Lessee, Lease, Description [Line Items]
Increase in operating lease obligations for right-of-use assets	0	117
Increase in finance lease obligations for investment in PP&E	16	3
Aggregate maximum lease limit, utilized	80
San Diego Gas and Electric Company [Member]
Lessee, Lease, Description [Line Items]
Increase in operating lease obligations for right-of-use assets	0	142
Increase in finance lease obligations for investment in PP&E	4	$ 4
Aggregate maximum lease limit, utilized	$ 62