Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
Sep. 30, 2020	Dec. 31, 2019
Other Current Assets [Member]
Loss Contingencies [Line Items]
Prepayments to suppliers	$ 5,545	$ 6,593

Payments of cash to suppliers for goods and services during the current period.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 17
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3367-108585

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 17
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3367-108585

Name:	us-gaap_PaymentsToSuppliers
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration