Stock-based Compensation - Allocation of Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Long Term Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total	$ 1,196	$ 812
Share-based Payment Arrangement, Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total	0	0
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total	1,529	3,248
Cost of sales | Long Term Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total	384	238
Cost of sales | Share-based Payment Arrangement, Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total	0	0
Cost of sales | Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total	490	351
Selling, General and Administrative Expenses [Member] | Long Term Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total	730	521
Selling, General and Administrative Expenses [Member] | Share-based Payment Arrangement, Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total	0	0
Selling, General and Administrative Expenses [Member] | Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total	1,005	2,881
Research and Development Expense [Member] | Long Term Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total	82	53
Research and Development Expense [Member] | Share-based Payment Arrangement, Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total	0	0
Research and Development Expense [Member] | Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total	$ 34	$ 16