Trade Accounts Receivable - Summary of Trade Accounts Receivable (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Accounts Receivable Net Current [Abstract]
Trade accounts receivable, current	$ 4,135	$ 3,932
Trade accounts receivable, long-term	224	0
Allowance for doubtful accounts	(25)	(25)
Trade accounts receivable, net	4,334	3,907
Unpaid deferred revenue included in trade accounts receivable	$ 590	$ 1,711

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

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 310
-SubTopic 10
-Section 50
-Paragraph 7A
-URI http://asc.fasb.org/extlink&oid=123577603&loc=SL6953401-111524

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 14
-URI http://asc.fasb.org/extlink&oid=124255953&loc=SL82919253-210447

Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=124255206&loc=SL82895884-210446

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant