Stock Options and Restricted Shares - Stock-based Compensation (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2015	Dec. 31, 2014
Stock-based compensation
Total	$ 429	$ 465	$ 1,166	$ 1,250
Cost of product revenue
Stock-based compensation
Total	9	16	29	40
General and administrative
Stock-based compensation
Total	327	300	902	910
Sales and marketing
Stock-based compensation
Total	74	139	210	281
Research and development
Stock-based compensation
Total	$ 19	$ 10	$ 25	$ 19