Fair Value of Financial Instruments - Summary of Financial Instruments Measured at Fair Value on Recurring Basis (Detail) - Fair Value, Recurring - Level 3 - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Beginning balance	$ 32,971	$ 15,572	$ 3,992
Acquisitions	45,204	5,401	2,951
Changes in fair value included in earnings	33,261	12,552	(510)
Payment of contingent consideration payable	(12,464)	(554)	(1,384)
Series A-2 compound embedded option	(9,361)
Issuance of warrant option	30,097		12,818
Write off of the contingent put option	12,140		(2,295)
Exercise of warrant options	(56,287)
Foreign currency translation of contingent consideration payment	(208)
Ending balance	75,353	32,971	15,572
Contingent Put Option
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Beginning balance	7,100
Changes in fair value included in earnings	(19,240)	7,100
Write off of the contingent put option	12,140
Ending balance		7,100
Business Acquisitions Contingent Consideration, Current
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Beginning balance	8,614	2,754	1,345
Acquisitions	34,661	5,022	2,951
Changes in fair value included in earnings	19,119	1,392	(158)
Payment of contingent consideration payable	(12,464)	(554)	(1,384)
Reclass of long term to short term contingent liabilities	180
Foreign currency translation of contingent consideration payment	(208)
Ending balance	49,902	8,614	2,754
Business Acquisitions Contingent Consideration, Long-Term
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Beginning balance	379
Acquisitions	10,543	379
Changes in fair value included in earnings	(6,177)
Reclass of long term to short term contingent liabilities	(180)
Ending balance	4,565	379
Conversion Option
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Changes in fair value included in earnings	30,247
Series A-2 compound embedded option	(9,361)
Ending balance	20,886
Warrant Options
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Beginning balance	16,878	12,818
Changes in fair value included in earnings	9,312	4,060
Issuance of warrant option	30,097		12,818
Exercise of warrant options	$ (56,287)
Ending balance		$ 16,878	12,818
Subordinated Debt Embedded Derivative
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Beginning balance			2,647
Changes in fair value included in earnings			(352)
Write off of the contingent put option			$ (2,295)

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Fair value measurement with unobservable inputs reconciliation recurring basis liability foreign currency translation of contingent consideration payment.

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Fair value measurement with unobservable inputs reconciliation recurring basis liability reclass of long term to short term contingent liabilities.

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Fair value measurement with unobservable inputs reconciliation recurring basis liability write off of contingent put option.

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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.

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Amount of gain (loss) recognized in income from liability measured at fair value on recurring basis using unobservable input (level 3).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
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-Section 50
-Paragraph 2
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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.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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Amount of purchases 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.

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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.

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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.

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