Intangible Assets and Goodwill (Components Intangible Assets) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Original cost	$ 15,556	$ 15,337
Accumulated amortization	(9,679)	(9,042)
Net identifiable intangible assets	5,877	6,295
Customer Relationships
Finite-Lived Intangible Assets [Line Items]
Original cost	5,005	4,928
Accumulated amortization	(2,366)	(2,194)
Net identifiable intangible assets	2,639	2,734
Developed Technology
Finite-Lived Intangible Assets [Line Items]
Original cost	8,365	8,225
Accumulated amortization	(6,470)	(6,043)
Net identifiable intangible assets	1,895	2,182
Trademarks / Trade-Names
Finite-Lived Intangible Assets [Line Items]
Original cost	2,186	2,184
Accumulated amortization	(843)	(805)
Net identifiable intangible assets	$ 1,343	$ 1,379