ACCUMULATED OTHER COMPREHENSIVE (LOSS) INCOME (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Foreign currency translation:
Balance at beginning of period	$ 691	$ 925
Change in cumulative translation adjustment before reclassifications	(146)	(234)
Foreign currency translation adjustments, taxes	0	0
Net current period other comprehensive loss	(146)	(234)
Balance at end of the period	545	691
Retirement plans:
Balance at beginning of period	(3,608)	(1,439)
Amortization of net actuarial loss and prior service cost	120	55
Net actuarial gain (loss) arising during the period	1,508	(2,224)
Amortization of accumulated other comprehensive loss into net periodic benefit costs, taxes	0	0
Net current period other comprehensive income (loss)	1,628	(2,169)
Balance at end of the period	(1,980)	(3,608)
Accumulated other comprehensive loss, net	$ (1,435)	$ (2,917)