VALUATION AND QUALIFYING ACCOUNTS (Details) - Allowance for doubtful accounts - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
BEGINNING BALANCE	$ 5,181	$ 4,865	$ 5,189
ADDITIONS CHARGED TO EXPENSE	2,579	2,023	1,616
OTHER	(2,056)	(1,707)	(1,940)
ENDING BALANCE	$ 5,704	$ 5,181	$ 4,865