ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Sep. 30, 2017
Changes in foreign currency translation
Beginning accumulated foreign currency translation	$ 1,053	$ 906
Change in cumulative translation adjustment before reclassifications	(6)	(70)
Income taxes	0	0
Net current period other comprehensive loss	(6)	(70)
Ending accumulated foreign currency translation	1,047	836
Changes in retirement plans
Beginning accumulated retirement plans benefit cost	(2,111)	(4,826)
Amortization of net actuarial loss and prior service cost	24	97
Income taxes	0	0
Net current period other comprehensive income	24	97
Ending accumulated retirement plans benefit cost	(2,087)	(4,729)
Accumulated other comprehensive loss, net of taxes	$ (1,040)	$ (3,893)	$ (1,058)