VALUATION AND QUALIFYING ACCOUNTS (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Valuation allowance for deferred tax assets
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
BEGINNING BALANCE	$ 4,035
ADDITIONS CHARGED TO EXPENSE	15,869
OTHER	(2,265)
ENDING BALANCE	17,639	$ 4,035
Allowance for doubtful accounts
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
BEGINNING BALANCE	6,148	5,704	$ 5,181
ADDITIONS CHARGED TO EXPENSE	2,238	2,387	2,579
OTHER	(1,144)	(1,943)	(2,056)
ENDING BALANCE	$ 7,242	$ 6,148	$ 5,704