Accounts Receivable, Net - Schedule of Accounts Receivable, Net (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Accounts Notes And Loans Receivable [Line Items]
Allowance for doubtful accounts	$ (70)	$ (70)
Total accounts receivable, net	15,106	10,731
Security Products
Accounts Notes And Loans Receivable [Line Items]
Accounts receivable, gross	12,018	8,797
Marine Components
Accounts Notes And Loans Receivable [Line Items]
Accounts receivable, gross	$ 3,158	$ 2,004

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
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=124259787&loc=d3e4428-111522

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(3))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 3: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section 45
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=124098289&loc=d3e6676-107765

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 9
-URI http://asc.fasb.org/extlink&oid=124259787&loc=d3e4531-111522

Name:	us-gaap_AccountsReceivableNetCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant