Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Finite Lived Intangible Assets Future Amortization Expense [Line Items]
Accumulated amortization	$ (13,478)	$ (12,629)
Intangible assets, net	12,977	13,826
Aggregate amortization expense:	849	4,629
Patents [Member]
Finite Lived Intangible Assets Future Amortization Expense [Line Items]
Gross carrying value	847	847
Technology [Member]
Finite Lived Intangible Assets Future Amortization Expense [Line Items]
Gross carrying value	13,789	13,789
Customer relationships [Member]
Finite Lived Intangible Assets Future Amortization Expense [Line Items]
Gross carrying value	9,911	9,911
Tradename [Member]
Finite Lived Intangible Assets Future Amortization Expense [Line Items]
Gross carrying value	1,867	1,867
Non-compete [Member]
Finite Lived Intangible Assets Future Amortization Expense [Line Items]
Gross carrying value	$ 41	$ 41