COMMITMENTS AND CONTINGENCIES - LESSEE CASH FLOW INFORMATION (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Operating activities:
Cash paid for operating leases	$ 81
Cash paid for finance leases - operating	130
Financing activities:
Cash paid for finance leases - financing	17
Increase in operating lease obligations for right-of-use assets	571
Increase in finance lease obligations for investment in PP&E	27	$ 7
Southern California Gas Company [Member]
Operating activities:
Cash paid for operating leases	21
Cash paid for finance leases - operating	0
Financing activities:
Cash paid for finance leases - financing	4
Increase in operating lease obligations for right-of-use assets	117
Increase in finance lease obligations for investment in PP&E	15	7
San Diego Gas and Electric Company [Member]
Operating activities:
Cash paid for operating leases	25
Cash paid for finance leases - operating	130
Financing activities:
Cash paid for finance leases - financing	13
Increase in operating lease obligations for right-of-use assets	147
Increase in finance lease obligations for investment in PP&E	$ 12	$ 0