Basis of Presentation and Summary of Significant Accounting Policies - Summary of Revenue by Timing of Revenue Recognition (Detail) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2018	Mar. 31, 2017
Disaggregation Of Revenue [Line Items]
Total revenue	$ 84,244	$ 72,308
Products and Services Transferred at a Point in Time [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	20,512	19,578
Products and Services Transferred Over Time [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	$ 63,732	$ 52,730

Total revenue from sale of goods and services rendered during the reporting period, in the normal course of business, reduced by sales returns and allowances, and sales discounts.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1)
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

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