Goodwill and Other Intangible Assets - Schedule of Changes in Carrying Value of Goodwill (Detail) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018
Goodwill [Line Items]
Goodwill, Beginning Balance		$ 26,421	$ 28,585
Accumulated impairment loss, Beginning Balance		(3,467)	(3,467)
Goodwill net, Beginning Balance		22,954	25,118
Goodwill acquired	[1]	3,497
Foreign currency translation		(365)	(2,164)
Goodwill, Ending Balance		29,553	26,421
Accumulated impairment loss, Ending Balance		(3,467)	(3,467)
Goodwill net, Ending Balance		26,086	22,954
Surfactants Segment [Member]
Goodwill [Line Items]
Goodwill, Beginning Balance		20,521	22,627
Accumulated impairment loss, Beginning Balance		(3,467)	(3,467)
Goodwill net, Beginning Balance		17,054	19,160
Goodwill acquired	[1]	3,497
Foreign currency translation		(354)	(2,106)
Goodwill, Ending Balance		23,664	20,521
Accumulated impairment loss, Ending Balance		(3,467)	(3,467)
Goodwill net, Ending Balance		20,197	17,054
Polymer Segment [Member]
Goodwill [Line Items]
Goodwill, Beginning Balance		5,417	5,475
Goodwill net, Beginning Balance		5,417	5,475
Foreign currency translation		(11)	(58)
Goodwill, Ending Balance		5,406	5,417
Goodwill net, Ending Balance		5,406	5,417
Specialty Products Segment [Member]
Goodwill [Line Items]
Goodwill, Beginning Balance		483	483
Goodwill net, Beginning Balance		483	483
Goodwill, Ending Balance		483	483
Goodwill net, Ending Balance		$ 483	$ 483

[1] See Note 21 for information regarding the goodwill acquired in a business combination.