VALUATION AND QUALIFYING ACCOUNTS (Details) - Allowance for doubtful accounts - USD ($) $ in Thousands		12 Months Ended
		Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
BEGINNING BALANCE		$ 5,704	$ 5,181	$ 4,865
ADDITIONS CHARGED TO EXPENSE		2,387	2,579	2,023
OTHER	[1]	(1,943)	(2,056)	(1,707)
ENDING BALANCE		$ 6,148	$ 5,704	$ 5,181

[1] Uncollectible accounts written off, less recoveries and adjustments.