Intangible Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets, Gross [Abstract]
Customer Lists And Rights To Sell	$ 75,424	$ 76,581
Trademarks, Formulations And Product Technology	33,561	33,025
Other Finite-Lived Intangible Assets, Gross	5,962	6,114
Total	114,947	115,720
Finite Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Accumulated Amortization	50,135	45,217
Customer Lists And Rights To Sell [Member]
Finite Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Accumulated Amortization	28,542	25,394
Trademarks Formulations and Product Technology [Member]
Finite Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Accumulated Amortization	15,987	14,309
Other Intangible Assets [Member]
Finite Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Accumulated Amortization	$ 5,606	$ 5,514