Segment Reporting - Operating Segment (Detail) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Net sales	[1]	$ 2,345,966	$ 1,869,750	$ 1,858,745
Operating income		170,781	171,522	127,260
Assets		2,065,612	1,752,336	1,579,367
Capital expenditures		194,482	125,792	105,572
Depreciation and amortization expenses		90,876	81,860	78,701
Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales		2,345,966	1,869,750	1,858,745
Operating income		253,768	251,281	208,762
Assets		1,880,106	1,472,738	1,331,929
Capital expenditures		189,006	121,163	103,354
Depreciation and amortization expenses		87,809	77,988	76,056
Surfactants [Member]
Segment Reporting Information [Line Items]
Net sales		1,562,795	1,351,686	1,272,723
Surfactants [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales		1,562,795	1,351,686	1,272,723
Operating income		165,999	169,101	122,780
Assets		1,245,207	1,018,555	907,032
Capital expenditures		154,953	88,484	69,725
Depreciation and amortization expenses		51,375	49,429	48,422
Polymers [Member]
Segment Reporting Information [Line Items]
Net sales		713,440	452,277	512,347
Polymers [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales		713,440	452,277	512,347
Operating income		73,591	68,214	69,567
Assets		556,799	361,219	338,179
Capital expenditures		29,077	26,719	29,188
Depreciation and amortization expenses		30,598	22,873	22,151
Specialty Products [Member]
Segment Reporting Information [Line Items]
Net sales		69,731	65,787	73,675
Specialty Products [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales		69,731	65,787	73,675
Operating income		14,178	13,966	16,415
Assets		78,100	92,964	86,718
Capital expenditures		4,976	5,960	4,441
Depreciation and amortization expenses		$ 5,836	$ 5,686	$ 5,483

[1] Net sales are attributed to countries based on the location of the Company legal entity making the sale.