Trade Accounts Receivable and Allowance for Doubtful Accounts - Summary of Trade Accounts Receivable (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Accounts Receivable Net Current [Abstract]
Trade accounts receivable	$ 3,932	$ 4,036
Allowance for doubtful accounts	(25)	(15)
Trade accounts receivable, net	3,907	4,021
Unpaid deferred revenue included in trade accounts receivable	$ 1,711	$ 2,015

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
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Reference 3: http://www.xbrl.org/2003/role/exampleRef
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