Stock-Based Compensation - Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2014
LTIPs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 2,619	$ 2,901	$ 1,428
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	163	552	839
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	1,992	1,059	642
Cost of sales | LTIPs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	720	1,075	523
Cost of sales | Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	81	233	421
Cost of sales | Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	617	269	62
Selling, general and administrative expenses | LTIPs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	1,732	1,547	712
Selling, general and administrative expenses | Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	78	306	413
Selling, general and administrative expenses | Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	1,352	787	580
Research and development | LTIPs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	167	279	193
Research and development | Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	4	13	5
Research and development | Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 23	$ 3	$ 0