Sales Recognition - Additional Information (Detail)	3 Months Ended
Mar. 31, 2021 USD ($)
New Accounting Pronouncements And Changes In Accounting Principles [Abstract]
Contract with customer, liability, revenue recognized	$ 19,000,000
Description of expected duration	With the exception of remaining performance obligations associated with our OneCall Support Services contracts which are included in the table above regardless of original duration, remaining performance obligations that have original expected durations of one year or less are not included in the table above. Amounts not included in the table above have an average original expected duration of eight months.
Time and material contracts expected duration	23 months

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

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