Goodwill and Other Intangible Assets (Schedule of Intangible Assets) (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Mar. 31, 2019	Jun. 30, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets
Gross Carrying Value		$ 82,821	$ 82,980
Accumulated Amortization		(36,384)	(33,144)
Net Carrying Amount		46,437	49,836
Non-compete agreements
Finite-Lived Intangible Assets
Gross Carrying Value		1,245	1,372
Accumulated Amortization		(1,082)	(1,046)
Net Carrying Amount		163	326
Patents
Finite-Lived Intangible Assets
Gross Carrying Value		374	358
Accumulated Amortization		(179)	(165)
Net Carrying Amount		195	193
Customer relationships
Finite-Lived Intangible Assets
Gross Carrying Value		37,093	37,129
Accumulated Amortization		(12,561)	(11,388)
Net Carrying Amount		24,532	25,741
Trademarks and trade names
Finite-Lived Intangible Assets
Gross Carrying Value		8,478	8,481
Accumulated Amortization		(3,883)	(3,416)
Net Carrying Amount		4,595	5,065
Technology
Finite-Lived Intangible Assets
Gross Carrying Value		35,631	35,640
Accumulated Amortization		(18,679)	(17,129)
Net Carrying Amount		$ 16,952	$ 18,511
Weighted Average
Finite-Lived Intangible Assets
Weighted Average Amortization Period In Years		15 years
Weighted Average | Non-compete agreements
Finite-Lived Intangible Assets
Weighted Average Amortization Period In Years	4 years	4 years
Weighted Average | Patents
Finite-Lived Intangible Assets
Weighted Average Amortization Period In Years	10 years	10 years
Weighted Average | Customer relationships
Finite-Lived Intangible Assets
Weighted Average Amortization Period In Years	18 years	18 years
Weighted Average | Trademarks and trade names
Finite-Lived Intangible Assets
Weighted Average Amortization Period In Years	15 years	15 years
Weighted Average | Technology
Finite-Lived Intangible Assets
Weighted Average Amortization Period In Years	14 years	14 years