Intangible Assets and Goodwill (Components Intangible Assets) (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Original cost	$ 15,328	$ 14,885
Accumulated amortization	(8,521)	(6,775)
Net identifiable intangible assets	$ 6,807	$ 8,110
Weighted-average useful lives (years)	9 years	9 years
Customer Relationships
Finite-Lived Intangible Assets [Line Items]
Original cost	$ 4,913	$ 4,759
Accumulated amortization	(2,043)	(1,577)
Net identifiable intangible assets	$ 2,870	$ 3,182
Weighted-average useful lives (years)	10 years	10 years
Developed Technology
Finite-Lived Intangible Assets [Line Items]
Original cost	$ 8,198	$ 7,917
Accumulated amortization	(5,675)	(4,509)
Net identifiable intangible assets	$ 2,523	$ 3,408
Weighted-average useful lives (years)	6 years	6 years
Trademarks / Trade-Names
Finite-Lived Intangible Assets [Line Items]
Original cost	$ 2,183	$ 2,178
Accumulated amortization	(769)	(658)
Net identifiable intangible assets	$ 1,414	$ 1,520
Weighted-average useful lives (years)	15 years	15 years
Covenants Not to Compete
Finite-Lived Intangible Assets [Line Items]
Original cost	$ 34	$ 31
Accumulated amortization	(34)	(31)
Net identifiable intangible assets	$ 0	$ 0
Weighted-average useful lives (years)	2 years	2 years