SIGNIFICANT ACCOUNTING POLICIES AND OTHER FINANCIAL DATA - CASH AND CASH EQUIVALENTS AND RESTRICTED CASH (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Presentation Of Restricted Cash [Line Items]
Restricted cash	$ 56,000,000	$ 76,000,000
Cash and cash equivalents	190,000,000	288,000,000
Restricted cash, current	35,000,000	62,000,000
Restricted cash, noncurrent	21,000,000	14,000,000
Total cash, cash equivalents and restricted cash on the Consolidated Statements of Cash Flows	246,000,000	364,000,000	$ 425,000,000	$ 450,000,000
SDG&E [Member]
Presentation Of Restricted Cash [Line Items]
Restricted cash	29,000,000	17,000,000
Sempra Mexico [Member]
Presentation Of Restricted Cash [Line Items]
Restricted cash	27,000,000	56,000,000
Sempra Renewables [Member]
Presentation Of Restricted Cash [Line Items]
Restricted cash		3,000,000
South America Utilities [Member]
Presentation Of Restricted Cash [Line Items]
Restricted cash	0	0
San Diego Gas and Electric Company [Member]
Presentation Of Restricted Cash [Line Items]
Cash and cash equivalents	8,000,000	12,000,000
Restricted cash, current	11,000,000	6,000,000
Restricted cash, noncurrent	18,000,000	11,000,000
Total cash, cash equivalents and restricted cash on the Consolidated Statements of Cash Flows	$ 37,000,000	$ 29,000,000	$ 20,000,000	$ 43,000,000