Consolidated Statements of Operations and Comprehensive (Loss) Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Income Statement [Abstract]
Revenue	$ 87,265	$ 85,617	$ 122,895
Cost of revenue	72,176	67,130	80,361
Gross profit	15,089	18,487	42,534
Operating expense:
Selling, general, and administrative	32,094	21,232	22,246
Research and development	19,443	15,387	12,542
Impairments	0	0	506
(Gain) loss from change in estimate on ARO obligation	(14)	145	(45)
(Gain) loss on sale of assets	(302)	34	(456)
Total operating expense	51,221	36,798	34,793
Operating loss	(36,132)	(18,311)	7,741
Other income:
Interest income, net	629	733	245
Foreign exchange (loss) gain	(427)	(434)	82
Other income	0	110	316
Total other (loss) income	202	409	643
Loss before income tax (expense) benefit	(35,930)	(17,902)	8,384
Income tax (expense) benefit	(54)	449	(163)
(Loss) income from continuing operations	(35,984)	(17,453)	8,221
Income from discontinued operations, net of tax	0	0	14
Net loss	(35,984)	(17,453)	8,235
Foreign exchange translation adjustment	65	324	(18)
Comprehensive (loss) income	$ (35,919)	$ (17,129)	$ 8,217
Per share data:
Net (loss) income per basic share, continuing operations (in usd per share)	$ (1.29)	$ (0.64)	$ 0.31
Net (loss) income per basic share, discontinued operations (in usd per share)	0.00	0.00	0.00
Net loss per basic share (in usd per share)	(1.29)	(0.64)	0.31
Net (loss) income per diluted share, continuing operations (in usd per share)	(1.29)	(0.64)	0.30
Net (loss) income per diluted share, discontinued operations (in usd per share)	0.00	0.00	0.00
Net (loss) income per diluted share (in usd per share)	$ (1.29)	$ (0.64)	$ 0.30
Weighted-average number of basic and diluted shares outstanding (in shares)	27,983	27,266	26,659
Weighted-average number of diluted shares outstanding (in shares)	27,983	27,266	27,544