INCOME TAXES (Details) - USD ($)	3 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2024	Dec. 31, 2021	Dec. 31, 2020	Sep. 30, 2019	May 31, 2019	Sep. 30, 2018
Operating Loss Carryforwards [Line Items]
Income tax expense (benefit), solar investment tax credit, net of deferred taxes							$ (10,000,000)
Unrecognized tax benefits	$ 4,900,000	$ 0
Forecasted effective tax rate	0.60%	(7.20%)
Tax credit carryforwards expected, net	$ 39,700,000					$ 47,700,000
Discrete adjustments, amount	$ 798,000	$ 1,300,000
Effective income tax	(0.30%)	(8.80%)
ITC carryforward	$ 158,700,000					154,200,000
Effective term	20 years
Deferred tax assets, operating loss carryforwards, domestic	$ 24,100,000
Deferred tax assets, operating loss carryforwards, domestic, refundable and receivables	22,800,000					22,800,000
Valuation allowance	$ 4,000,000					4,000,000
Investment tax credit, solar property	30.00%						30.00%
Scenario, Forecast
Operating Loss Carryforwards [Line Items]
Investment tax credit, solar property			10.00%	22.00%	26.00%
Federal
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	$ 134,000,000							$ 134,000,000
State
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	$ 340,200,000					$ 340,200,000
State | Minimum
Operating Loss Carryforwards [Line Items]
Effective term	7 years
State | Maximum
Operating Loss Carryforwards [Line Items]
Effective term	20 years