GENERAL INFORMATION AND OTHER FINANCIAL DATA - CREDIT LOSSES (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2020	Dec. 31, 2019
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 29
Provisions for expected credit losses	84
Write-offs	(11)
Ending balance	103
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	0
Reduction to expected credit losses	(3)
Ending balance	3
Allowance for credit losses	3	$ 3	$ 0
San Diego Gas and Electric Company [Member]
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	14
Provisions for expected credit losses	44
Write-offs	(6)
Ending balance	52
Southern California Gas Company [Member]
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	15
Provisions for expected credit losses	40
Write-offs	(5)
Ending balance	50
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	6
Allowance for credit losses	6		6
Cumulative Effect, Period of Adoption, Adjustment [Member] | San Diego Gas and Electric Company [Member]
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	0
Cumulative Effect, Period of Adoption, Adjustment [Member] | Southern California Gas Company [Member]
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	0
Accounts Receivable, Trade, Net [Member]
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Ending balance	75
Accounts Receivable, Trade, Net [Member] | San Diego Gas and Electric Company [Member]
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Ending balance	37
Accounts Receivable, Trade, Net [Member] | Southern California Gas Company [Member]
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Ending balance	37
Accounts receivable – other, net [Member]
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Ending balance	28
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	13
Due from Unconsolidated Affiliates - Noncurrent [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Ending balance	3
Allowance for credit losses	3	3
Sempra LNG [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Maximum exposure under guarantor obligations		4,000
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Reduction of credit loss liability	$ (3)
Sempra LNG [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Liability for credit losses			$ 6
Sempra LNG [Member] | Other Current Liabilities [Member]
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Liability for credit losses		$ 3
Sempra Mexico [Member] | Revenue Benchmark [Member] | Customer One [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Concentration risk percentage threshold	10.00%
Sempra Mexico [Member] | Revenue Benchmark [Member] | Customer Two [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Concentration risk percentage threshold	10.00%
Sempra Mexico [Member] | Revenue Benchmark [Member] | Customer Three [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Concentration risk percentage threshold	10.00%
Sempra Mexico [Member] | Revenue Benchmark [Member] | Customer Four [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Concentration risk percentage threshold	10.00%