Consolidated Statements of Operations and Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2015
Income Statement [Abstract]
Product revenue	$ 66,224	$ 64,897	$ 65,881
Service revenue	3,987	2,745	6,329
Total revenue	70,211	67,642	72,210
Cost of product revenue	49,630	49,630	68,388
Cost of service revenue	3,244	2,015	4,959
Total cost of revenue	52,874	51,645	73,347
Gross profit (loss)	17,337	15,997	(1,137)
Operating expenses:
General and administrative	14,777	16,884	14,908
Impairment of assets	250	6,023	0
Acquisition and integration related expenses	0	0	47
Sales and marketing	12,833	11,343	13,290
Research and development	2,004	1,668	2,554
Total operating expenses	29,864	35,918	30,799
Loss from operations	(12,527)	(19,921)	(31,936)
Other income (expense):
Other income	215	0	0
Interest expense	(273)	(297)	(376)
Interest income	36	128	300
Total other expense	(22)	(169)	(76)
Loss before income tax	(12,549)	(20,090)	(32,012)
Income tax (benefit) expense	(261)	36	49
Net loss and comprehensive loss	$ (12,288)	$ (20,126)	$ (32,061)
Basic net loss per share attributable to common shareholders (usd per share)	$ (0.44)	$ (0.73)	$ (1.43)
Weighted-average common shares outstanding (shares)	28,156,382	27,627,693	22,353,419
Diluted net loss per share (usd per share)	$ (0.44)	$ (0.73)	$ (1.43)
Weighted-average common shares and share equivalents outstanding (shares)	28,156,382	27,627,693	22,353,419