Components of Basic and Diluted Earnings Per Share (Detail) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Numerator:
Net income attributable to American Vanguard	$ 2,987	$ 2,772	$ 781	$ 51	$ 1,805	$ 732	$ 145	$ 2,159	$ 6,591	$ 4,841	$ 34,449
Denominator:
Weighted average shares outstanding-basic									28,673	28,436	28,301
Dilutive effect of stock options and grants									564	476	598
Weighted average shares outstanding-assuming dilution									29,237	28,912	28,899