REVENUES - RECEIVABLES FROM REVENUES FROM CONTRACTS WITH CUSTOMERS (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Contract with Customer, Asset [Line Items]
Receivables from revenues from contracts with customers	$ 1,166	$ 1,127
Accounts receivable – trade, net [Member]
Contract with Customer, Asset [Line Items]
Receivables from revenues from contracts with customers	1,145	1,106
Accounts receivable – other, net [Member]
Contract with Customer, Asset [Line Items]
Receivables from revenues from contracts with customers	14	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	1	6
San Diego Gas and Electric Company [Member]
Contract with Customer, Asset [Line Items]
Receivables from revenues from contracts with customers	405	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	390	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	12	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	676	639
Southern California Gas Company [Member] | Accounts receivable – trade, net [Member]
Contract with Customer, Asset [Line Items]
Receivables from revenues from contracts with customers	674	634
Southern California Gas Company [Member] | Accounts receivable – other, net [Member]
Contract with Customer, Asset [Line Items]
Receivables from revenues from contracts with customers	$ 2	$ 5