Business Restructuring - Additional Information (Detail) (USD $)	3 Months Ended
	Dec. 31, 2014 Employees	Sep. 30, 2014 Employees	Mar. 31, 2014	Dec. 31, 2013
Restructuring Cost And Reserve [Line Items]
Number of employees accepting voluntary termination incentive	13
Restructuring charges against income	$ 1,722,000
Number of North American positions eliminated		16
Accelerated depreciation expenses			907,000
Surfactants [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring charge for estimated severance expense related to an approved plan				$ 1,040,000