Revenue from Contracts with Customers - Summary of Geographic Disaggregation of Net Sales (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Disaggregation Of Revenue [Line Items]
Net sales	$ 595,511	$ 460,549	$ 1,133,251	$ 910,536
Surfactants [Member]
Disaggregation Of Revenue [Line Items]
Net sales	384,002	332,335	754,938	659,406
Polymers [Member]
Disaggregation Of Revenue [Line Items]
Net sales	190,538	112,409	340,923	218,900
Specialty Products [Member]
Disaggregation Of Revenue [Line Items]
Net sales	20,971	15,805	37,390	32,230
North America [Member]
Disaggregation Of Revenue [Line Items]
Net sales	335,054	289,680	640,804	572,961
North America [Member] | Surfactants [Member]
Disaggregation Of Revenue [Line Items]
Net sales	221,645	207,571	442,580	415,517
North America [Member] | Polymers [Member]
Disaggregation Of Revenue [Line Items]
Net sales	95,591	68,780	166,469	130,621
North America [Member] | Specialty Products [Member]
Disaggregation Of Revenue [Line Items]
Net sales	17,818	13,329	31,755	26,823
Europe [Member]
Disaggregation Of Revenue [Line Items]
Net sales	150,228	90,980	292,104	190,131
Europe [Member] | Surfactants [Member]
Disaggregation Of Revenue [Line Items]
Net sales	65,339	55,812	136,433	115,472
Europe [Member] | Polymers [Member]
Disaggregation Of Revenue [Line Items]
Net sales	82,453	32,692	150,753	69,252
Europe [Member] | Specialty Products [Member]
Disaggregation Of Revenue [Line Items]
Net sales	2,436	2,476	4,918	5,407
Latin America [Member]
Disaggregation Of Revenue [Line Items]
Net sales	81,671	56,657	142,830	103,806
Latin America [Member] | Surfactants [Member]
Disaggregation Of Revenue [Line Items]
Net sales	79,968	56,194	140,137	102,704
Latin America [Member] | Polymers [Member]
Disaggregation Of Revenue [Line Items]
Net sales	986	463	1,976	1,102
Latin America [Member] | Specialty Products [Member]
Disaggregation Of Revenue [Line Items]
Net sales	717		717
Asia [Member]
Disaggregation Of Revenue [Line Items]
Net sales	28,558	23,232	57,513	43,638
Asia [Member] | Surfactants [Member]
Disaggregation Of Revenue [Line Items]
Net sales	17,050	12,758	35,788	25,713
Asia [Member] | Polymers [Member]
Disaggregation Of Revenue [Line Items]
Net sales	$ 11,508	$ 10,474	$ 21,725	$ 17,925