Revenue - Additional Information (Detail)	3 Months Ended	9 Months Ended
Sep. 30, 2021 USD ($)	Sep. 30, 2021 USD ($) Category	Dec. 31, 2020 USD ($)
Revenue [Line Items]
Number of categories \| Category		3
Remaining performance obligations	$ 0	$ 0
Recognized revenue	2,000,000.0	9,800,000
Other Than Maintenance Services [Member]
Revenue [Line Items]
Remaining performance obligations	$ 20,700,000	$ 20,700,000	$ 17,700,000

Amount of revenue recognized that was previously included in balance of obligation to transfer good or service to customer for which consideration from customer has been received or is due.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 8
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130549-203045

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