WILDFIRE-RELATED CONTINGENCIES (Insurance) (Details) - USD ($) $ in Millions		12 Months Ended
	Jul. 01, 2020	Dec. 31, 2020	Jul. 31, 2020	Dec. 31, 2019
Loss Contingencies [Line Items]
Prepaid insurance		$ 536.0
Insurance premium costs, recovery, coverage amount		1,400.0
Insurance receivable		674.0		$ 2,238.0
Insurance Coverage For Wildfire and Non-Wildfire Events
Loss Contingencies [Line Items]
Costs for insurance coverage	$ 859.0
Insurance Coverage For Wildfire and Non-Wildfire Events | August 1, 2019 through July 31, 2020
Loss Contingencies [Line Items]
Costs for insurance coverage		212.0
Insurance Coverage for Wildfire Events
Loss Contingencies [Line Items]
Liability insurance coverage			$ 867.5
Initial self-insured retention per occurrence			60.0
Insurance Coverage for Wildfire Events | August 1, 2019 through July 31, 2020
Loss Contingencies [Line Items]
Liability insurance coverage		430.0
Initial self-insured retention per occurrence		10.0
Insurance Coverage for Wildfire Events | August 1, 2019 through September 2, 2020
Loss Contingencies [Line Items]
Liability insurance coverage			825.0
Insurance Coverage for Wildfire Events | July 1, 2020 - June 30, 2021
Loss Contingencies [Line Items]
Reinsurance			42.5
Insurance Coverage For Non-Wildfire Liabilities | August 1, 2019 through July 31, 2020
Loss Contingencies [Line Items]
Liability insurance coverage		520.0
Initial self-insured retention per occurrence		10.0
Insurance Coverage For Non-Wildfire Liabilities | September 3, 2019 through September 2, 2020
Loss Contingencies [Line Items]
Liability insurance coverage		480.0
Insurance Coverage For Non-Wildfire Liabilities | August 1, 2020 - July 31, 2021
Loss Contingencies [Line Items]
Liability insurance coverage			700.0
Initial self-insured retention per occurrence			$ 10.0
2019 Kincade Fire
Loss Contingencies [Line Items]
Insurance receivable		430.0		0.0
2020 Zogg Fire
Loss Contingencies [Line Items]
Initial self-insured retention per occurrence		60.0
Insurance receivable		219.0		0.0
2017 Northern California wildfires
Loss Contingencies [Line Items]
Insurance receivable		25.0		$ 808.0
Estimated insurance recoveries, pending to receive		$ 25.0