SIGNIFICANT ACCOUNTING POLICIES AND OTHER FINANCIAL DATA - CASH, CASH EQUIVALENTS AND RESTRICTED CASH (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Presentation Of Restricted Cash [Line Items]
Cash and cash equivalents	$ 960	$ 108
Restricted cash, current	22	31
Restricted cash, noncurrent	3	3
Cash, cash equivalents and restricted cash in discontinued operations	0	75
Total cash, cash equivalents and restricted cash on the Consolidated Statements of Cash Flows	985	217	$ 246	$ 364
Discontinued Operations, Held-for-sale [Member] | Sempra South American Utilities [Member]
Presentation Of Restricted Cash [Line Items]
Cash, cash equivalents and restricted cash in discontinued operations		1
Cash and cash equivalents	$ 4,600	$ 74