Investment in Associated Companies - Narrative (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Schedule Of Equity Method Investments [Line Items]
Equity Method Investments	$ 21,316	$ 25,690
Nippon Quaker (Japan) [Member]
Schedule Of Equity Method Investments [Line Items]
Equity Method Investment Ownership Percentage	50.00%
Nippon Quaker (Japan) [Member] | Asia Pacific [Member]
Schedule Of Equity Method Investments [Line Items]
Equity Method Investments	$ 6,200
Kelko (Venezuela) [Member]
Schedule Of Equity Method Investments [Line Items]
Equity Method Investment Ownership Percentage	50.00%
Kelko (Venezuela) [Member] | South America [Member]
Schedule Of Equity Method Investments [Line Items]
Equity Method Investments	$ 0
Kelko (Panama) [Member]
Schedule Of Equity Method Investments [Line Items]
Equity Method Investment Ownership Percentage	50.00%
Kelko (Panama) [Member] | South America [Member]
Schedule Of Equity Method Investments [Line Items]
Equity Method Investments	$ 400
Primex (Barbados) [Member]
Schedule Of Equity Method Investments [Line Items]
Equity Method Investment Ownership Percentage	33.00%
Primex (Barbados) [Member] | North America [Member]
Schedule Of Equity Method Investments [Line Items]
Equity Method Investments	$ 14,700