Fair Value Measurements - Roll-Forward of Fair Value of Earn-out Consideration Categorized as Level 3 in Fair Value Hierarchy (Parenthetical) (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2019
Fair Value Disclosures [Abstract]
Payment of earn-out consideration include in cash flows from operating activities	$ 680	$ 4,308

Amount of cash outflow, not made soon after acquisition date of business combination, to settle contingent consideration liability exceeding amount recognized at acquisition date. Includes, but is not limited to, measurement period adjustment and less amount paid soon after acquisition date.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 17
-Subparagraph (ee)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3367-108585

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