Fair Value Measurements - Schedule of Reconciliation of Contingent Consideration Measured at Fair Value on Recurring Basis (Detail) - Contingent Consideration [Member] - USD ($) $ in Thousands  | 
3 Months Ended | |
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Mar. 31, 2021  | 
Mar. 31, 2020  | 
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| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
| Beginning balance | $ 5,572 | $ 3,387 | 
| Contingent consideration in connection with acquisitions | (100) | 0 | 
| Change in fair value of contingent consideration | (171) | (225) | 
| Payments of contingent consideration | 0 | 0 | 
| Ending balance | $ 5,301 | $ 3,162 | 
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available. 
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- Definition Amount of issuances of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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- Definition Amount of increase (decrease) of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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- Definition Amount of settlements of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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- Definition Fair value of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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- Details 
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