INCOME TAXES - UNRECOGNIZED TAX BENEFITS (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Contingency [Line Items]
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	$ 1	$ 1
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense	0	1	$ 0
Reconciliation of Unrecognized Tax Benefits
Beginning balance	119	89	90
Increase in prior period tax positions	5	7	22
Decrease in prior period tax positions	0	(1)	(15)
Increase in current period tax positions	2	24	4
Settlements with taxing authorities	(32)	0	(12)
Expiration of statutes of limitations	(1)	0	0
Ending balance	93	119	89
Of the total, amounts related to tax positions that, if recognized, in future years, would decrease the effective tax rate	(81)	(107)	(77)
Of the total, amounts related to tax positions that, if recognized, in future years, would increase the effective tax rate	27	24	20
San Diego Gas and Electric Company [Member]
Income Tax Contingency [Line Items]
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	0	0
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense	0	0	0
Reconciliation of Unrecognized Tax Benefits
Beginning balance	11	10	22
Increase in prior period tax positions	1	1	9
Decrease in prior period tax positions	0	0	(11)
Settlements with taxing authorities	0	0	(10)
Ending balance	12	11	10
Of the total, amounts related to tax positions that, if recognized, in future years, would decrease the effective tax rate	(9)	(9)	(7)
Of the total, amounts related to tax positions that, if recognized, in future years, would increase the effective tax rate	1	1	1
Southern California Gas Company [Member]
Income Tax Contingency [Line Items]
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	0	0
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense	0	0	0
Reconciliation of Unrecognized Tax Benefits
Beginning balance	61	35	29
Increase in prior period tax positions	1	2	3
Increase in current period tax positions	2	24	4
Increase Resulting from Settlements with Taxing Authorities	0
Settlements with taxing authorities		0	(1)
Ending balance	64	61	35
Of the total, amounts related to tax positions that, if recognized, in future years, would decrease the effective tax rate	(55)	(51)	(26)
Of the total, amounts related to tax positions that, if recognized, in future years, would increase the effective tax rate	$ 26	$ 23	$ 20