Schedule of Quarterly Data (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Statement [Abstract]
Net sales	$ 87,468	$ 82,447	$ 72,724	$ 69,474	$ 83,808	$ 72,486	$ 66,523	$ 66,565	$ 312,113	$ 289,382	$ 298,634
Gross profit	36,404	32,986	31,395	27,503	30,698	31,433	25,121	24,650	128,288	111,902	114,496
Net income attributable to American Vanguard	$ 3,871	$ 2,877	$ 3,246	$ 2,794	$ 2,987	$ 2,772	$ 781	$ 51	$ 12,788	$ 6,591	$ 4,841
Basic net income per share	$ 0.13	$ 0.10	$ 0.11	$ 0.10	$ 0.10	$ 0.10	$ 0.03		$ 0.44	$ 0.23	$ 0.17
Diluted net income per share	$ 0.13	$ 0.10	$ 0.11	$ 0.10	$ 0.10	$ 0.09	$ 0.03		$ 0.44	$ 0.23	$ 0.17