SUPPLEMENTAL CASH FLOW INFORMATION (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Current assets:
Accounts receivable	$ (7,045)	$ (10,632)	$ 7,566
Inventories	(2,289)	10,453	17,001
Other current assets	4,447	12,434	(14,567)
Total change in current assets	(4,887)	12,255	10,000
Current liabilities:
Trade accounts payable	5,672	(11,083)	(9,103)
Accrued compensation	(2,469)	147	(183)
Accrued income taxes	5,054	4,079	3,389
Other current liabilities	2,414	8,317	(6,854)
Total change in current liabilities	10,671	1,460	(12,751)
Net change	$ 5,784	$ 13,715	$ (2,751)