Segment Reporting - Operating Segment (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Segment Reporting Information [Line Items]
Net Sales	$ 444,011	$ 491,429	$ 1,356,876	$ 1,472,982
Surfactants [Member]
Segment Reporting Information [Line Items]
Net Sales	290,830	318,486	921,124	987,957
Polymers [Member]
Segment Reporting Information [Line Items]
Net Sales	134,726	152,955	377,703	420,332
Specialty Products [Member]
Segment Reporting Information [Line Items]
Net Sales	$ 18,455	$ 19,988	$ 58,049	$ 64,693