Summary of Long Term Debt (Detail) - USD ($) $ in Thousands		Dec. 31, 2017	Dec. 31, 2016
Debt Disclosure [Abstract]
Revolving line of credit	[1]	$ 78,425	$ 41,400
Less debt issuance costs		(939)	(449)
Long term debt, non current		$ 77,486	$ 40,951

[1] As of June 30, 2017, AMVAC, the Company’s principal operating subsidiary, as borrower, and affiliates (including the Company, AMVAC CV and AMVAC BV), as guarantors and/or borrowers, entered into a Third Amendment to Second Amended and Restated Credit Agreement (the “Credit Agreement”) with a group of commercial lenders led by Bank of the West (AMVAC’s primary bank) as agent, swing line lender and Letter of Credit (“L/C”) issuer. The Credit Agreement is a senior secured lending facility, consisting of a line of credit of up to $250,000, an accordion feature of up to $100,000 and a maturity date of June 30, 2022. The Credit Agreement contains two key financial covenants; namely, borrowers are required to maintain a Consolidated Funded Debt Ratio of no more than 3.25-to-1 and a Consolidated Fixed Charge Covenant Ratio of at least 1.25-to-1. The Company’s borrowing capacity varies with its financial performance, measured in terms of EBITDA, for the trailing twelve month period. Under the Credit Agreement, revolving loans bear interest at a variable rate based, at borrower’s election with proper notice, on either (i) LIBOR plus the “Applicable Rate” which is based upon the Consolidated Funded Debt Ratio (“Eurocurrency Rate Loan”) or (ii) the greater of (x) the Prime Rate, (y) the Federal Funds Rate plus 0.5%, and (z) the Daily One-Month LIBOR Rate plus 1.00%, plus, in the case of (x), (y) or (z) the Applicable Rate (“Alternate Base Rate Loan”). Interest payments for Eurocurrency Rate Loans are payable on the last day of each interest period (either one, two, three or six months, as selected by the borrower) and the maturity date, while interest payments for Alternate Base Rate Loans are payable on the last business day of each month and the maturity date.