Investments in Associated Companies - Summarized Financial Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Equity Method Investment Summarized Financial Information Income Statement [Abstract]
Equity in net income of associated companies	$ 5,064	$ 1,763	$ 3,285
Korea Houghton Coporation [Member]
Equity Method Investment Summarized Financial Information Income Statement [Abstract]
Equity in net income of associated companies	2,337	0	0
Equity Method Investee Name Nippon Quaker Japan [Member]
Equity Method Investment Summarized Financial Information Income Statement [Abstract]
Equity in net income of associated companies	850	713	585
Equity Method Investee Name Kelko Panama [Member]
Equity Method Investment Summarized Financial Information Income Statement [Abstract]
Equity in net income of associated companies	55	222	195
Equity Method Investee Name Kelko Venezuela [Member]
Equity Method Investment Summarized Financial Information Income Statement [Abstract]
Equity in net income of associated companies	0	(138)	(42)
Equity Method Investee Name Primex [Member]
Equity Method Investment Summarized Financial Information Income Statement [Abstract]
Equity in net income of associated companies	$ 1,822	$ 966	$ 2,547