Segment Reporting - Operating Segment (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Segment Reporting Information [Line Items]
Net Sales	$ 452,414	$ 504,111	$ 912,865	$ 981,553
Surfactants [Member]
Segment Reporting Information [Line Items]
Net Sales	299,743	333,761	630,294	669,471
Polymers [Member]
Segment Reporting Information [Line Items]
Net Sales	133,613	148,270	242,977	267,377
Specialty Products [Member]
Segment Reporting Information [Line Items]
Net Sales	$ 19,058	$ 22,080	$ 39,594	$ 44,705