OTHER INCOME (EXPENSE) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Other Income and Expenses [Abstract]
Other income (expense)	$ 3,331	$ 2,885	$ 5,230
Currency exchange gains (losses)	(81)	(915)	(438)
Investment income (loss)	283	184	(40)
Net periodic benefit cost (credit)	(907)	(1,559)	(3,148)
Rental income	$ 1,848	$ 1,848	$ 1,848