ACCUMULATED OTHER COMPREHENSIVE LOSS (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Sep. 30, 2017
Foreign currency translation:
Beginning accumulated foreign currency translation	$ 866	$ 858	$ 1,053	$ 906
Change in cumulative translation adjustment before reclassifications	(76)	81	(263)	33
Income taxes	0	0	0	0
Net current period other comprehensive (loss) income	(76)	81	(263)	33
Ending accumulated foreign currency translation	790	939	790	939
Retirement plans:
Beginning accumulated retirement plans benefit cost	(2,048)	(4,633)	(2,111)	(4,826)
Amortization of net actuarial loss and prior service cost	30	51	93	244
Income taxes	0	0	0	0
Net current period other comprehensive income	30	51	93	244
Ending accumulated retirement plans benefit cost	(2,018)	(4,582)	(2,018)	(4,582)
Accumulated other comprehensive loss, net of taxes	$ (1,228)	$ (3,643)	$ (1,228)	$ (3,643)	$ (1,058)