Stock-Based Compensation - Stock Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019
Share-based Payment Arrangement, Additional Disclosure [Abstract]
Stock-based compensation expense	$ 249	$ 303	$ 678	$ 669
Cost of goods sold
Share-based Payment Arrangement, Additional Disclosure [Abstract]
Stock-based compensation expense	22	17	59	52
Research and development
Share-based Payment Arrangement, Additional Disclosure [Abstract]
Stock-based compensation expense	11	12	29	33
Selling, general and administrative
Share-based Payment Arrangement, Additional Disclosure [Abstract]
Stock-based compensation expense	$ 216	$ 274	$ 590	$ 584