Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid- In Capital	Accumulated Other Comprehensive Income (Loss)	Retained Earnings (Accumulated Deficit)
Beginning balance (in shares) at Sep. 30, 2017		14,711,000
Beginning balance at Sep. 30, 2017	$ 90,483	$ 147	$ 125,564	$ (8,529)	$ (26,699)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	6,452				6,452
Translation adjustment	541			541
Stock compensation expense	253		253
Stock options exercised (in shares)		165,000
Stock options exercised	1,200	$ 2	1,198
Ending balance (in shares) at Dec. 31, 2017		14,876,000
Ending balance at Dec. 31, 2017	98,929	$ 149	127,015	(7,988)	(20,247)
Beginning balance (in shares) at Sep. 30, 2017		14,711,000
Beginning balance at Sep. 30, 2017	90,483	$ 147	125,564	(8,529)	(26,699)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	9,287
Ending balance (in shares) at Mar. 31, 2018		14,896,000
Ending balance at Mar. 31, 2018	102,912	$ 149	127,367	(7,192)	(17,412)
Beginning balance (in shares) at Dec. 31, 2017		14,876,000
Beginning balance at Dec. 31, 2017	98,929	$ 149	127,015	(7,988)	(20,247)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	2,835				2,835
Translation adjustment	796			796
Stock compensation expense	210		210
Stock options exercised (in shares)		20,000
Stock options exercised	142	$ 0	142
Ending balance (in shares) at Mar. 31, 2018		14,896,000
Ending balance at Mar. 31, 2018	$ 102,912	$ 149	127,367	(7,192)	(17,412)
Beginning balance (in shares) at Sep. 30, 2018	14,216,596	14,217,000
Beginning balance at Sep. 30, 2018	$ 93,090	$ 142	124,316	(9,974)	(21,394)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	(2,372)				(2,372)
Translation adjustment	(576)			(576)
Stock compensation expense	169		169
Stock options exercised (in shares)		11,000
Stock options exercised	37	$ 0	37
Ending balance (in shares) at Dec. 31, 2018		14,228,000
Ending balance at Dec. 31, 2018	$ 90,348	$ 142	124,522	(10,550)	(23,766)
Beginning balance (in shares) at Sep. 30, 2018	14,216,596	14,217,000
Beginning balance at Sep. 30, 2018	$ 93,090	$ 142	124,316	(9,974)	(21,394)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	$ (8,007)
Ending balance (in shares) at Mar. 31, 2019	14,227,580	14,228,000
Ending balance at Mar. 31, 2019	$ 84,697	$ 142	124,716	(10,760)	(29,401)
Beginning balance (in shares) at Dec. 31, 2018		14,228,000
Beginning balance at Dec. 31, 2018	90,348	$ 142	124,522	(10,550)	(23,766)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	(5,635)				(5,635)
Translation adjustment	(210)			(210)
Stock compensation expense	194		194
Stock options exercised (in shares)		0
Stock options exercised	$ 0	$ 0	0
Ending balance (in shares) at Mar. 31, 2019	14,227,580	14,228,000
Ending balance at Mar. 31, 2019	$ 84,697	$ 142	$ 124,716	$ (10,760)	$ (29,401)