Business Restructuring - Additional Information (Detail)	1 Months Ended	3 Months Ended			9 Months Ended
	Jun. 30, 2017 Employees	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)	[1]	Sep. 30, 2018 USD ($) Employees	Sep. 30, 2017 USD ($)
Restructuring Cost And Reserve [Line Items]
Business restructuring		$ 1,715,000	$ 426,000		$ 2,346,000	$ 1,798,000	[1]
Germany [Member] | Surfactants [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring costs		1,410,000
Singapore [Member] | Surfactants [Member]
Restructuring Cost And Reserve [Line Items]
Number positions eliminated | Employees	11
Restructuring liability		$ 0			$ 0
Singapore [Member] | Surfactants [Member] | Termination Benefits [Member]
Restructuring Cost And Reserve [Line Items]
Business restructuring						$ 132,000
Longford Mills [Member] | Surfactants [Member]
Restructuring Cost And Reserve [Line Items]
Number positions eliminated | Employees					30
Business restructuring					$ 5,775,000
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					$ 4,181,000

[1] The 2017 data has been immaterially changed from the amounts originally reported as a result of the Company’s first quarter 2018 adoption of ASU No. 2017-7, Compensation-Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost