Intangible Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets, Gross [Abstract]
Customer Lists And Rights To Sell	$ 73,554	$ 74,989
Trademarks, Formulations And Product Technology	33,264	33,275
Other Finite-Lived Intangible Assets, Gross	5,842	5,840
Total	112,660	114,104
Finite Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Accumulated Amortization	53,905	51,622
Customer Lists And Rights To Sell [Member]
Finite Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Accumulated Amortization	30,541	29,587
Trademarks Formulations and Product Technology [Member]
Finite Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Accumulated Amortization	17,640	16,469
Other Intangible Assets [Member]
Finite Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Accumulated Amortization	$ 5,724	$ 5,566