Business Restructuring - Additional Information (Detail)	3 Months Ended		6 Months Ended
	Jun. 30, 2016 USD ($)	Mar. 31, 2016 USD ($)	Dec. 31, 2016 USD ($)	Jun. 30, 2016 USD ($) Employees
Restructuring Cost And Reserve [Line Items]
Restructuring expenses	$ 1,061,000			$ 1,061,000
Ethoxylation Assets [Member]
Restructuring Cost And Reserve [Line Items]
Depreciation expense		$ 1,084,000
Longford Mills [Member] | Surfactants [Member]
Restructuring Cost And Reserve [Line Items]
Number positions eliminated | Employees				30
Restructuring expenses	1,061,000			$ 1,061,000
Depreciation expense	$ 843,000			$ 1,927,000
Longford Mills [Member] | Surfactants [Member] | Scenario Forecast [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring expenses			$ 3,000,000
Depreciation expense			$ 2,600,000