GENERAL INFORMATION AND OTHER FINANCIAL DATA - CREDIT LOSSES (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 138	$ 29
Provisions for expected credit losses	43	6
Write-offs	(5)	(4)
Recoveries	0	1
Ending balance	176	33
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	3	0
Provisions for expected credit losses	(2)	1
Ending balance	1	7
Allowance for credit losses	1	7	$ 1
San Diego Gas and Electric Company [Member]
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	69	14
Provisions for expected credit losses	15	3
Write-offs	(3)	(3)
Recoveries	0	1
Ending balance	81	15
Southern California Gas Company [Member]
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	68	15
Provisions for expected credit losses	28	3
Write-offs	(2)	(1)
Ending balance	94	17
Cumulative Effect, Period of Adoption, Adjustment [Member]
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance		1
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	0	6
Allowance for credit losses	0	$ 6
Accounts Receivable, Trade, Net [Member]
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Ending balance	146
Accounts Receivable, Trade, Net [Member] | San Diego Gas and Electric Company [Member]
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Ending balance	66
Accounts Receivable, Trade, Net [Member] | Southern California Gas Company [Member]
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Ending balance	79
Accounts receivable – other, net [Member]
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Ending balance	30
Accounts receivable – other, net [Member] | San Diego Gas and Electric Company [Member]
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Ending balance	15
Accounts receivable – other, net [Member] | Southern California Gas Company [Member]
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Ending balance	15
Due from Unconsolidated Affiliates - Noncurrent [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Ending balance	1
Allowance for credit losses	$ 1		1
Sempra LNG [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Maximum exposure under guarantor obligations			$ 4,000