Business Restructuring and Asset Impairments - Additional Information (Detail)	1 Months Ended	3 Months Ended			12 Months Ended
	Jun. 30, 2017 Employees	Dec. 31, 2017 USD ($)	Jun. 30, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2018 USD ($) Employees	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
2018 Restructuring [Member] | Germany [Member] | Surfactants [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring costs					$ 1,404,000
2017 Restructuring [Member] | Fieldsboro, NJ [Member]
Restructuring Cost And Reserve [Line Items]
Business restructuring		$ 915,000
Depreciation expense		$ 1,290,000
2017 Restructuring [Member] | Singapore [Member] | Surfactants [Member]
Restructuring Cost And Reserve [Line Items]
Number positions eliminated | Employees	11
2017 Restructuring [Member] | Singapore [Member] | Surfactants [Member] | Termination Benefits [Member]
Restructuring Cost And Reserve [Line Items]
Business restructuring			$ 132,000			$ 0
2016 Restructuring [Member] | Longford Mills [Member]
Restructuring Cost And Reserve [Line Items]
Business restructuring					1,185,000	2,022,000
2016 Restructuring [Member] | Longford Mills [Member] | Other Expense [Member]
Restructuring Cost And Reserve [Line Items]
Business restructuring					1,185,000	2,022,000
2016 Restructuring [Member] | Longford Mills [Member] | Surfactants [Member]
Restructuring Cost And Reserve [Line Items]
Business restructuring					6,024,000
Depreciation expense					$ 0	$ 0	$ 4,471,000
Number positions eliminated | Employees					30
Decommissioning expense					$ 1,185,000
2016 Restructuring [Member] | Longford Mills [Member] | Surfactants [Member] | Termination Benefits [Member]
Restructuring Cost And Reserve [Line Items]
Business restructuring					1,594,000
2016 Restructuring [Member] | Longford Mills [Member] | Surfactants [Member] | Other Expense [Member]
Restructuring Cost And Reserve [Line Items]
Business restructuring					$ 4,430,000
2016 Asset Impairments [Member] | Surfactants [Member]
Restructuring Cost And Reserve [Line Items]
Asset impairment charges				$ 4,247,000
2016 Asset Impairments [Member] | United States [Member] | Nonionic Surfactants [Member]
Restructuring Cost And Reserve [Line Items]
Asset impairment charges				2,297,000
2016 Asset Impairments [Member] | Brazil [Member] | Bahia Plant
Restructuring Cost And Reserve [Line Items]
Asset impairment charges				$ 1,950,000
2016 Asset Impairments [Member] | Brazil [Member] | Bahia Plant | Take-Or-Pay Contract [Member] | Net Sales [Member]
Restructuring Cost And Reserve [Line Items]
Compensation for lost future revenues							$ 4,250,000