Segment Reporting - Operating Segment (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Segment Reporting Information [Line Items]
Net Sales	$ 445,897	$ 460,451
Surfactants [Member]
Segment Reporting Information [Line Items]
Net Sales	309,960	330,551
Polymers [Member]
Segment Reporting Information [Line Items]
Net Sales	113,898	109,364
Specialty Products [Member]
Segment Reporting Information [Line Items]
Net Sales	$ 22,039	$ 20,536