Property, Plant and Equipment - Schedule of Costs and Accumulated Depreciation (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Mar. 31, 2017
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 115,662	$ 115,881
Less accumulated depreciation	(79,224)	(72,443)
Property, plant and equipment, net	36,438	43,438
Land
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	3,643	3,643
Construction in progress - equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	606	601
Buildings
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	34,549	34,549
Equipment and software
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	73,798	73,445
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	1,154	1,201
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 1,912	$ 2,442