Goodwill and Other Intangible Assets (Schedule of Intangible Assets) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets
Gross Carrying Value	$ 82,980	$ 88,181
Accumulated Amortization	(33,144)	(30,741)
Net Carrying Amount	49,836	57,440
Non-compete agreements
Finite-Lived Intangible Assets
Gross Carrying Value	1,372	4,238
Accumulated Amortization	(1,046)	(3,100)
Net Carrying Amount	326	1,138
Patents
Finite-Lived Intangible Assets
Gross Carrying Value	358	389
Accumulated Amortization	(165)	(164)
Net Carrying Amount	193	225
Customer relationships
Finite-Lived Intangible Assets
Gross Carrying Value	37,129	37,679
Accumulated Amortization	(11,388)	(9,171)
Net Carrying Amount	25,741	28,508
Trademarks and trade names
Finite-Lived Intangible Assets
Gross Carrying Value	8,481	10,085
Accumulated Amortization	(3,416)	(4,091)
Net Carrying Amount	5,065	5,994
Technology
Finite-Lived Intangible Assets
Gross Carrying Value	35,640	35,790
Accumulated Amortization	(17,129)	(14,215)
Net Carrying Amount	$ 18,511	$ 21,575
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	5 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	17 years
Weighted Average | Trademarks and trade names
Finite-Lived Intangible Assets
Weighted Average Amortization Period In Years	15 years	14 years
Weighted Average | Technology
Finite-Lived Intangible Assets
Weighted Average Amortization Period In Years	14 years	14 years