Condensed Consolidated Statements of Operations and Comprehensive Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016
Income Statement [Abstract]
Revenue	$ 32,591	$ 21,532	$ 62,767	$ 44,022
Cost of revenue	21,553	14,510	41,686	29,599
Gross profit	11,038	7,022	21,081	14,423
Operating expense:
Selling, general, and administrative	5,672	4,825	11,250	9,646
Research and development	3,141	2,564	5,340	5,124
Impairments	468	0	468	0
Total operating expense	9,281	7,389	17,058	14,770
Operating income (loss)	1,757	(367)	4,023	(347)
Other income (expense):
Interest income, net	46	25	69	8
Foreign exchange gain (loss)	44	25	(359)	(110)
Total other income (expense)	90	50	(290)	(102)
Income (loss) from continuing operations before income tax benefit (expense)	1,847	(317)	3,733	(449)
Income tax benefit (expense)	8	155	(112)	153
Income (loss) from continuing operations	1,855	(162)	3,621	(296)
(Loss) income from discontinued operations, net of tax	(7)	4,144	(16)	5,265
Net income	1,848	3,982	3,605	4,969
Foreign exchange translation adjustment	276	43	16	(45)
Comprehensive income	$ 2,124	$ 4,025	$ 3,621	$ 4,924
Net income (loss) per basic share:
Net income (loss) per basic share, continuing operations, (in usd per share)	$ 0.07	$ (0.01)	$ 0.14	$ (0.01)
Net income per basic share, discontinued operations (in usd per share)	0.00	0.16	0.00	0.20
Net income per basic share (in usd per share)	0.07	0.15	0.14	0.19
Net income (loss) per diluted share:
Net income (loss) per diluted share, continuing operations (in usd per share)	0.07	(0.01)	0.13	(0.01)
Net income per diluted share, discontinued operations (in usd per share)	0.00	0.16	0.00	0.20
Net income per diluted share (in usd per share)	$ 0.07	$ 0.15	$ 0.13	$ 0.19
Weighted-average number of basic shares outstanding (in shares)	26,622	25,942	26,449	25,818
Weighted-average number of basic shares outstanding (in shares)	27,585	25,942	27,366	25,818