INCOME TAXES - Effective income tax rate (Details)	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
INCOME TAXES
Federal statutory income tax rate	21.00%	21.00%
Increases (decreases):
State and local income taxes, net of Federal tax benefit, if applicable	(0.10%)	(0.40%)
Other nondeductible expenses	1.30%	(11.50%)
Goodwill	(3.10%)	0.00%
Valuation allowance changes	(22.30%)	(9.60%)
Effective income tax rate	(3.20%)	(0.50%)