Consolidated Statements of Operations and Comprehensive (Loss) Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Income Statement [Abstract]
Revenue	$ 85,617	$ 122,895	$ 91,998
Cost of revenue	67,130	80,361	61,044
Gross profit	18,487	42,534	30,954
Operating expense (income):
Selling, general, and administrative	21,232	22,246	20,734
Research and development	15,387	12,542	9,921
Impairments	0	506	0
Recovery of previously incurred litigation related fees and expenses from arbitration award	0	0	(2,599)
Loss (gain) from change in estimate on ARO obligation	145	(45)	0
Loss (gain) on sale of assets	34	(456)	(41)
Total operating expense	36,798	34,793	28,015
Operating (loss) income	(18,311)	7,741	2,939
Other income (expense):
Interest income, net	733	245	88
Foreign exchange (loss) gain	(434)	82	(394)
Other income	110	316	0
Total other income (expense)	409	643	(306)
Income (loss) from continuing operations before income taxes	(17,902)	8,384	2,633
Income tax benefit (expense)	449	(163)	(14)
(Loss) income from continuing operations	(17,453)	8,221	2,619
Income from discontinued operations, net of tax	0	14	5,647
Undistributed earnings allocated to common shareholders for basic and diluted net income per share	(17,453)	8,235	8,266
Foreign exchange translation adjustment	324	(18)	(268)
Comprehensive (loss) income	$ (17,129)	$ 8,217	$ 7,998
Net (loss) income per basic share:
Continuing operations (in usd per share)	$ (0.64)	$ 0.31	$ 0.10
Discontinued operations (in usd per share)	0.00	0.00	0.22
Net (loss) income per basic share (in usd per share)	(0.64)	0.31	0.32
Net (loss) income per diluted share:
Continuing operations (in usd per share)	(0.64)	0.30	0.10
Discontinued operations (in usd per share)	0.00	0.00	0.21
Net income per diluted share (in usd per share)	$ (0.64)	$ 0.30	$ 0.31
Weighted-average number of basic shares outstanding (in shares)	27,266	26,659	25,979
Weighted-average number of basic shares outstanding (in shares)	27,266	27,544	26,518