GENERAL INFORMATION AND OTHER FINANCIAL DATA - CREDIT LOSSES (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Mar. 31, 2021
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 138	$ 29
Provisions for expected credit losses	66	21
Write-offs	(12)	(7)
Ending balance	192	44
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	3	0
Provisions for expected credit losses	(2)	(3)
Ending balance	1	3
Allowance for credit losses	1	3
San Diego Gas and Electric Company [Member]
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	69	14
Provisions for expected credit losses	13	9
Write-offs	(7)	(4)
Ending balance	75	19
Southern California Gas Company [Member]
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	68	15
Provisions for expected credit losses	52	12
Write-offs	(5)	(3)
Ending balance	115	24
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
Accounts Receivable, Trade, Net [Member]
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Ending balance	153
Accounts Receivable, Trade, Net [Member] | San Diego Gas and Electric Company [Member]
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Ending balance	60
Accounts Receivable, Trade, Net [Member] | Southern California Gas Company [Member]
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Ending balance	91
Accounts receivable – other, net [Member]
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Ending balance	39
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	24
Due from Unconsolidated Affiliates - Noncurrent [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Ending balance	1
Allowance for credit losses	1
Sempra LNG [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Maximum exposure under guarantor obligations			$ 4,000
Sempra LNG [Member] | Deferred Credits and Other [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Ending balance	7
Allowance for credit losses	$ 7