Net Sales - Summary of Net Sales Disaggregated by Principal Markets (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Net sales:
Net sales	$ 127,199	$ 73,969	$ 366,011	$ 262,413
Chemical [Member]
Net sales:
Net sales	127,199	73,969	366,011	262,413
Chemical [Member] | Agricultural Products [Member]
Net sales:
Net sales	51,102	31,986	162,523	138,441
Chemical [Member] | Industrial Acids and Other Chemical Products [Member]
Net sales:
Net sales	63,920	32,372	164,803	97,137
Chemical [Member] | Mining Products [Member]
Net sales:
Net sales	$ 12,177	$ 9,611	$ 38,685	$ 26,835