Segment Reporting - Reconciliation of Segment Information to Income Before Provision for Income Taxes (Detail) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Segment Reporting Information [Line Items]
Operating Income		$ 54,659	$ 40,213	$ 195,645	$ 150,784
Business restructuring		(92)	(72)	(225)	(267)
Other Income (Expense)
Interest, net		(2,221)	(1,599)	(7,254)	(4,690)
Other, net		(1,980)	702	(8,999)	4,206
Income before provision for income taxes		50,458	39,316	179,392	150,300
Operating Segments [Member]
Segment Reporting Information [Line Items]
Operating Income		80,525	56,647	244,145	206,339
Operating Segments [Member] | Surfactants [Member]
Segment Reporting Information [Line Items]
Operating Income		38,976	34,452	140,994	133,558
Operating Segments [Member] | Polymers [Member]
Segment Reporting Information [Line Items]
Operating Income		31,864	19,753	79,905	60,729
Operating Segments [Member] | Specialty Products [Member]
Segment Reporting Information [Line Items]
Operating Income		9,685	2,442	23,246	12,052
Segment Reconciling Items [Member]
Segment Reporting Information [Line Items]
Unallocated corporate expenses	[1]	$ (25,774)	$ (16,362)	$ (48,275)	$ (55,288)

[1] Unallocated corporate expenses are primarily comprised of corporate administrative expenses (e.g., corporate finance, legal, human resources, information systems, deferred compensation and environmental remediation) that are not included in segment operating income and are not used to evaluate segment performance.