Intangible Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Mar. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	$ 71,968	$ 71,968
Finite-Lived Intangible Assets, Accumulated Amortization	(68,690)	(60,533)
Finite-Lived Intangible Assets, Net	3,278	11,435
Backlog [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	1,530	1,530
Finite-Lived Intangible Assets, Accumulated Amortization	(1,530)	(1,530)
Finite-Lived Intangible Assets, Net	0	0
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	23,260	23,260
Finite-Lived Intangible Assets, Accumulated Amortization	(21,196)	(14,320)
Finite-Lived Intangible Assets, Net	2,064	8,940
Product Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	45,195	45,195
Finite-Lived Intangible Assets, Accumulated Amortization	(44,148)	(43,034)
Finite-Lived Intangible Assets, Net	1,047	2,161
Noncompete Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	510	510
Finite-Lived Intangible Assets, Accumulated Amortization	(510)	(510)
Finite-Lived Intangible Assets, Net	0	0
Trademarks and Trade Names [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	1,473	1,473
Finite-Lived Intangible Assets, Accumulated Amortization	(1,306)	(1,139)
Finite-Lived Intangible Assets, Net	$ 167	$ 334