Business Restructuring - Additional Information (Detail)	1 Months Ended	3 Months Ended		6 Months Ended		14 Months Ended
	Jun. 30, 2017 USD ($) Employees	Jun. 30, 2017 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2017 USD ($) Employees
Restructuring Cost And Reserve [Line Items]
Business restructuring		$ 586,000	$ 1,061,000	$ 1,372,000	$ 1,061,000
Longford Mills [Member] | Surfactants [Member]
Restructuring Cost And Reserve [Line Items]
Business restructuring						$ 4,057,000
Number positions eliminated | Employees						30
Expected restructuring expenses	$ 4,500,000	4,500,000		4,500,000		$ 4,500,000
Longford Mills [Member] | Surfactants [Member] | Termination Benefits [Member]
Restructuring Cost And Reserve [Line Items]
Business restructuring						1,594,000
Longford Mills [Member] | Surfactants [Member] | Other Expense [Member]
Restructuring Cost And Reserve [Line Items]
Business restructuring						$ 2,463,000
Singapore Plant [Member] | Surfactants [Member]
Restructuring Cost And Reserve [Line Items]
Number positions eliminated | Employees	11
Singapore Plant [Member] | Surfactants [Member] | Termination Expense [Member]
Restructuring Cost And Reserve [Line Items]
Business restructuring		$ 132,000		$ 132,000