WILDFIRE-RELATED CONTINGENCIES (2019 Kincade Fire and 2020 Zogg Fire) (Details) $ in Millions		12 Months Ended
	Nov. 04, 2019 numberOfPeople	Dec. 31, 2020 USD ($)	Feb. 24, 2021 numberOfPlaintiff plaintiff complaint	Sep. 27, 2020 a structure fatality injury	Dec. 31, 2019 USD ($)	Oct. 23, 2019 a structure injury customer numberOfFatality
Loss Contingencies [Line Items]
Cumulative reimbursements from insurance policies		$ 649.0
Insurance receivable		674.0			$ 2,238.0
2019 Kincade Fire
Loss Contingencies [Line Items]
Number of acres burned (acre) | a						77,758
Number of fatalities (fatality) | numberOfFatality						0
Number of injuries | injury						4
Number of structures destroyed (structure) | structure						374
Number of residences destroyed (residence) | structure						174
Number of commercial structures destroyed (structure) | structure						11
Number of other structures destroyed (structures) | structure						189
Number of structures damaged (structure) | structure						60
Number of residential structures damaged (structure) | structure						35
Number of commercial structures damaged (structure) | structure						1
Number of other structures damaged (structure) | structure						24
Number of people part of mandatory evacuation order | numberOfPeople	200,000
Number of customers without power | customer						27,837
Potential loss contingency		625.0
Loss contingency, claim eligibility requirement amount		1,000.0
Cumulative reimbursements from insurance policies		430.0
Insurance receivable		430.0			0.0
2019 Kincade Fire | Subsequent Event
Loss Contingencies [Line Items]
Number of complaint | complaint			22
Number of plaintiffs represented by complaints | plaintiff			504
2020 Zogg Fire
Loss Contingencies [Line Items]
Number of acres burned (acre) | a				56,338
Number of fatalities (fatality) | fatality				4
Number of injuries | injury				1
Number of structures destroyed (structure) | structure				204
Number of structures damaged (structure) | structure				27
Potential loss contingency		275.0
Loss contingency, claim eligibility requirement amount		1,000.0
Cumulative reimbursements from insurance policies		219.0
Number of single family homes destroyed | structure				63
Insurance receivable		219.0			$ 0.0
Initial self-insured retention per occurrence		60.0
Legal fees		4.0
2020 Zogg Fire | Maximum
Loss Contingencies [Line Items]
Cumulative reimbursements from insurance policies		$ 867.5
2020 Zogg Fire | Subsequent Event
Loss Contingencies [Line Items]
Number of complaint | complaint			6
Number of plaintiffs represented by complaints | numberOfPlaintiff			240