Accounts Receivable, Net - Schedule of Accounts Receivable, Net (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Accounts Notes And Loans Receivable [Line Items]
Allowance for doubtful accounts	$ (70)	$ (70)
Total accounts receivable, net	13,433	12,140
Security Products
Accounts Notes And Loans Receivable [Line Items]
Accounts receivable, gross	11,239	10,596
Marine Components
Accounts Notes And Loans Receivable [Line Items]
Accounts receivable, gross	$ 2,264	$ 1,614

Amount, after allowance for credit loss, of right to consideration from customer for product sold and service rendered in normal course of business, classified as current.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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