Goodwill and Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2017
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Accumulated Amortization	$ (23,115)	$ (22,598)
Intangible Assets, Net (Including Goodwill)	57,297	59,907
Finite-Lived Intangible Assets, Net	42,140	44,433
Finite-Lived Intangible Assets, Gross	65,255	67,031
Intangible Assets, Gross (Excluding Goodwill)	80,412	82,505
Indefinite-Lived Trademarks	15,157	15,474
Intangible Assets, Net (Excluding Goodwill)	57,297	59,907
Goodwill	40,294	$ 40,294
Amortization of Intangible Assets	1,100		$ 900
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months	4,500
Finite-Lived Intangible Assets, Amortization Expense, after Year Five	$ 19,300
Purchased Technology Customer Relationships And Patents [Member] | Weighted Average [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	15 years 9 months 12 days	15 years 9 months 12 days
Patents [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Accumulated Amortization	$ (10,980)	$ (10,625)
Finite-Lived Intangible Assets, Net	15,682	16,037
Finite-Lived Patents, Gross	26,662	26,662
Amortization of Intangible Assets	300		400
Finite-Lived Intangible Assets, Amortization Expense, after Year Five	8,600
Finite-Lived Intangible Assets, Amortization Expense, Year Four	1,400
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Accumulated Amortization	(11,911)	(11,735)
Finite-Lived Intangible Assets, Net	26,458	28,396
Finite-Lived Customer Relationships, Gross	38,369	$ 40,131
Amortization of Intangible Assets	$ 800		$ 500
Finite-Lived Intangible Asset, Useful Life	12 years 3 months 12 days	12 years 3 months 12 days
Finite-Lived Intangible Assets, Amortization Expense, after Year Five	$ 10,700
Finite-Lived Intangible Assets, Amortization Expense, Year Four	3,100
Other Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Accumulated Amortization	(224)	$ (238)
Finite-Lived Intangible Assets, Net	0	0
Other Finite-Lived Intangible Assets, Gross	224	238
Trademarks [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible Assets, Net (Excluding Goodwill)	$ 15,157	$ 15,474