REVENUES - RECEIVABLES FROM REVENUES FROM CONTRACTS WITH CUSTOMERS (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Contract with Customer, Asset [Line Items]
Receivables from revenues from contracts with customers	$ 891	$ 1,127
Accounts receivable – trade, net [Member]
Contract with Customer, Asset [Line Items]
Receivables from revenues from contracts with customers	875	1,106
Accounts receivable – other, net [Member]
Contract with Customer, Asset [Line Items]
Receivables from revenues from contracts with customers	10	11
Due from unconsolidated affiliates – current [Member]
Contract with Customer, Asset [Line Items]
Receivables from revenues from contracts with customers	6	4
Assets held-for-sale [Member]
Contract with Customer, Asset [Line Items]
Receivables from revenues from contracts with customers	0	6
San Diego Gas and Electric Company [Member]
Contract with Customer, Asset [Line Items]
Receivables from revenues from contracts with customers	456	377
San Diego Gas and Electric Company [Member] | Accounts receivable – trade, net [Member]
Contract with Customer, Asset [Line Items]
Receivables from revenues from contracts with customers	446	368
San Diego Gas and Electric Company [Member] | Accounts receivable – other, net [Member]
Contract with Customer, Asset [Line Items]
Receivables from revenues from contracts with customers	7	6
San Diego Gas and Electric Company [Member] | Due from unconsolidated affiliates – current [Member]
Contract with Customer, Asset [Line Items]
Receivables from revenues from contracts with customers	3	3
Southern California Gas Company [Member]
Contract with Customer, Asset [Line Items]
Receivables from revenues from contracts with customers	359	639
Southern California Gas Company [Member] | Accounts receivable – trade, net [Member]
Contract with Customer, Asset [Line Items]
Receivables from revenues from contracts with customers	356	634
Southern California Gas Company [Member] | Accounts receivable – other, net [Member]
Contract with Customer, Asset [Line Items]
Receivables from revenues from contracts with customers	$ 3	$ 5