Summary of Business Sales by Product and Geographic Location (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Net sales
Net sales	$ 117,439	$ 124,884	$ 317,956	$ 337,664
Change in net sales	117,439	$ (7,445)	317,956	$ (19,708)
Percentage change in net sales		(6.00%)		(6.00%)
Gross profit:
Gross profit	43,265	$ 47,463	121,952	$ 130,818
Change in gross profit	43,265	$ (4,198)	121,952	$ (8,866)
Percentage change in gross profit		(9.00%)		(7.00%)
US
Net sales
Net sales	66,612	$ 74,067	186,511	$ 200,136
Change in net sales	66,612	$ (7,455)	186,511	$ (13,625)
Percentage change in net sales		(10.00%)		(7.00%)
Gross profit:
Gross profit	28,904	$ 33,570	86,654	$ 90,503
Change in gross profit	28,904	$ (4,666)	86,654	$ (3,849)
Percentage change in gross profit		(14.00%)		(4.00%)
US \| Crop
Net sales
Net sales	48,361	$ 55,072	148,630	$ 158,068
Change in net sales	48,361	$ (6,711)	148,630	$ (9,438)
Percentage change in net sales		(12.00%)		(6.00%)
Gross profit:
Gross profit	20,146	$ 23,710	68,119	$ 69,059
Change in gross profit	20,146	$ (3,564)	68,119	$ (940)
Percentage change in gross profit		(15.00%)		(1.00%)
US \| Non-Crop
Net sales
Net sales	18,251	$ 18,995	37,881	$ 42,068
Change in net sales	18,251	$ (744)	37,881	$ (4,187)
Percentage change in net sales		(4.00%)		(10.00%)
Gross profit:
Gross profit	8,758	$ 9,860	18,535	$ 21,444
Change in gross profit	8,758	$ (1,102)	18,535	$ (2,909)
Percentage change in gross profit		(11.00%)		(14.00%)
International
Net sales
Net sales	50,827	$ 50,817	131,445	$ 137,528
Change in net sales	50,827	$ 10	131,445	$ (6,083)
Percentage change in net sales		0.00%		(4.00%)
Gross profit:
Gross profit	14,361	$ 13,893	35,298	$ 40,315
Change in gross profit	$ 14,361	$ 468	$ 35,298	$ (5,017)
Percentage change in gross profit		3.00%		(12.00%)