SIGNIFICANT ACCOUNTING POLICIES AND OTHER FINANCIAL DATA - CASH, CASH EQUIVALENTS AND RESTRICTED CASH (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016		Dec. 31, 2015	[2]	Dec. 31, 2014	[2]
Presentation Of Restricted Cash [Line Items]
Restricted cash	$ 76	$ 76
Cash and cash equivalents	288	349	[1]
Restricted cash, current	62	66	[1]
Restricted cash, noncurrent	14	10	[1]
Total cash, cash equivalents and restricted cash on the Consolidated Statements of Cash Flows	364	425	[2]	$ 450		$ 610
SDG&E [Member]
Presentation Of Restricted Cash [Line Items]
Restricted cash	17	12
Sempra Mexico [Member]
Presentation Of Restricted Cash [Line Items]
Restricted cash	56	61
Sempra Renewables [Member]
Presentation Of Restricted Cash [Line Items]
Restricted cash	3	3
San Diego Gas and Electric Company [Member]
Presentation Of Restricted Cash [Line Items]
Cash and cash equivalents	12	8	[1]
Restricted cash, current	6	11	[1]
Restricted cash, noncurrent	11	1	[1]
Total cash, cash equivalents and restricted cash on the Consolidated Statements of Cash Flows	$ 29	$ 20	[2]	$ 43		$ 27

[1] Reflects reclassifications to conform to current year presentation, which we discuss in Note 1.

[2] As adjusted for the retrospective adoption of ASU 2016-15 and ASU 2016-18, which we discuss in Note 2.