SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Allowance for Doubtful Accounts [Member]
Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of year	$ 1,747	$ 1,828	$ 1,224
Amounts charged to expenses	185	26	588
Deductions and adjustments	(32)	(107)	16
Balance at end of year	1,900	1,747	1,828
Valuation Allowance [Member]
Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of year	2,271	3,022	3,079
Amounts charged to expenses	0	0	0
Deductions and adjustments	(2,138)	(751)	(57)
Balance at end of year	$ 133	$ 2,271	$ 3,022