Intangible Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets, Gross [Abstract]
Finite-Lived Customer Lists, Gross	$ 76,663	$ 76,581
Trademarks, Formulations And Product Technology, Gross	34,221	33,025
Other Finite-Lived Intangible Assets, Gross	6,123	6,114
Total	117,007	115,720
Finite Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Accumulated Amortization	47,235	45,217
Customer Lists [Member]
Finite Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Accumulated Amortization	26,626	25,394
Trademarks, Formulations And Product Technology [Member]
Finite Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Accumulated Amortization	15,007	14,309
Other Intangible Assets [Member]
Finite Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Accumulated Amortization	$ 5,602	$ 5,514