Business Combinations - Total consideration and the estimated fair value of the assets acquired and liabilities assumed (Details) $ in Thousands					9 Months Ended
	Sep. 09, 2021 USD ($)	May 20, 2021 USD ($)	Apr. 05, 2021 USD ($)	Jan. 12, 2021 USD ($)	Sep. 30, 2021 USD ($) item	Dec. 31, 2020 USD ($)
Intangible assets:
Goodwill					$ 170,427	$ 28,289
Customer relationships
Intangible assets:
Weighted Average Useful Life (in years)					10 years
Acquired technology
Intangible assets:
Weighted Average Useful Life (in years)					5 years
Trademarks and tradenames
Intangible assets:
Weighted Average Useful Life (in years)					11 years
Non-competition agreements
Intangible assets:
Weighted Average Useful Life (in years)					2 years
Value of business acquired
Intangible assets:
Weighted Average Useful Life (in years)					1 year
Renewal rights
Intangible assets:
Weighted Average Useful Life (in years)					8 years
January 12, 2021 Acquisition ("V12 Data")
Purchase consideration:
Cash				$ 20,346
Contingent consideration - liability-classified				1,410
Total purchase consideration:				21,756
Assets:
Cash, cash equivalents and restricted cash				1,035
Current assets				4,939
Property and equipment				$ 996
Intangible assets:
Weighted Average Useful Life (in years)				7 years 7 months 6 days
Goodwill				$ 16,760
Total assets acquired				30,170
Current liabilities				(6,388)
Long-term liabilities				(2,026)
Net assets acquired				21,756
January 12, 2021 Acquisition ("V12 Data") | Customer relationships
Intangible assets:
Intangible assets, finite-lived				1,650
January 12, 2021 Acquisition ("V12 Data") | Acquired technology
Intangible assets:
Intangible assets, finite-lived				3,525
January 12, 2021 Acquisition ("V12 Data") | Trademarks and tradenames
Intangible assets:
Intangible assets, finite-lived				1,225
January 12, 2021 Acquisition ("V12 Data") | Non-competition agreements
Intangible assets:
Intangible assets, finite-lived				$ 40
April 5, 2021 Acquisition ("HOA")
Purchase consideration:
Cash			$ 82,355
Issuance of common stock			21,687
Common stock consideration payable			3,014
Payable			9,700
Contingent consideration - equity-classified			6,685
Total purchase consideration:			113,741
Assets:
Cash, cash equivalents and restricted cash			17,766
Current assets			235,669
Property and equipment			$ 2,267
Intangible assets:
Weighted Average Useful Life (in years)			9 years 6 months
Intangible assets, finite-lived			$ 41,952
Intangible assets, indefinite			4,960
Goodwill			47,361
Other non-current assets			55,165
Total assets acquired			400,180
Current liabilities			(273,759)
Long-term liabilities			(8,913)
Deferred tax liabilities, net			(3,767)
Net assets acquired			113,741
April 5, 2021 Acquisition ("HOA") | Insurance licenses
Intangible assets:
Intangible assets, indefinite			$ 4,960
April 5, 2021 Acquisition ("HOA") | Customer relationships
Intangible assets:
Weighted Average Useful Life (in years)			10 years
Intangible assets, finite-lived			$ 16,700
April 5, 2021 Acquisition ("HOA") | Trademarks and tradenames
Intangible assets:
Weighted Average Useful Life (in years)			10 years
Intangible assets, finite-lived			$ 12,200
April 5, 2021 Acquisition ("HOA") | Value of business acquired
Intangible assets:
Weighted Average Useful Life (in years)			1 year
Intangible assets, finite-lived			$ 400
April 5, 2021 Acquisition ("HOA") | Renewal rights
Intangible assets:
Weighted Average Useful Life (in years)			8 years
Intangible assets, finite-lived			$ 7,692
May 20, 2021 Acquisition ("Rynoh")
Purchase consideration:
Cash		$ 32,302
Common stock consideration payable		3,500
Payable		3,500
Total purchase consideration:		35,802
Assets:
Cash, cash equivalents and restricted cash		408
Current assets		932
Property and equipment		$ 334
Intangible assets:
Weighted Average Useful Life (in years)		10 years
Intangible assets, finite-lived		$ 16,590
Goodwill		21,952
Total assets acquired		40,216
Current liabilities		(409)
Deferred tax liabilities, net		(4,005)
Net assets acquired		$ 35,802
May 20, 2021 Acquisition ("Rynoh") | Customer relationships
Intangible assets:
Weighted Average Useful Life (in years)		10 years
Intangible assets, finite-lived		$ 12,700
May 20, 2021 Acquisition ("Rynoh") | Acquired technology
Intangible assets:
Weighted Average Useful Life (in years)		7 years
Intangible assets, finite-lived		$ 2,900
May 20, 2021 Acquisition ("Rynoh") | Trademarks and tradenames
Intangible assets:
Weighted Average Useful Life (in years)		20 years
Intangible assets, finite-lived		$ 900
May 20, 2021 Acquisition ("Rynoh") | Non-competition agreements
Intangible assets:
Weighted Average Useful Life (in years)		1 year
Intangible assets, finite-lived		$ 90
September 9, 2021 Acquisition ("AHP")
Purchase consideration:
Cash	$ 43,750
Common stock consideration payable	2,500
Payable	2,500
Total purchase consideration:	46,250
Assets:
Cash, cash equivalents and restricted cash	5,078
Current assets	9,761
Property and equipment	$ 17
Intangible assets:
Weighted Average Useful Life (in years)	7 years
Intangible assets, finite-lived	$ 2,742
Goodwill	43,095
Other non-current assets	25
Total assets acquired	60,718
Current liabilities	(14,389)
Long-term liabilities	(79)
Net assets acquired	$ 46,250
September 9, 2021 Acquisition ("AHP") | Trademarks and tradenames
Intangible assets:
Weighted Average Useful Life (in years)	10 years
Intangible assets, finite-lived	$ 700
September 9, 2021 Acquisition ("AHP") | Renewal rights
Intangible assets:
Weighted Average Useful Life (in years)	6 years
Intangible assets, finite-lived	$ 2,042
Other Acquisitions
Purchase consideration:
Cash					$ 25,321
Issuance of common stock					3,106
Contingent consideration - liability-classified					327
Total purchase consideration:					28,754
Assets:
Cash, cash equivalents and restricted cash					1,106
Current assets					1,579
Property and equipment					80
Intangible assets:
Goodwill					13,582
Other non-current assets					1,000
Total assets acquired					32,432
Current liabilities					(2,252)
Long-term liabilities					(1,000)
Deferred tax liabilities, net					(426)
Net assets acquired					28,754
Other Acquisitions | Customer relationships
Intangible assets:
Intangible assets, finite-lived					8,900
Other Acquisitions | Acquired technology
Intangible assets:
Intangible assets, finite-lived					970
Other Acquisitions | Trademarks and tradenames
Intangible assets:
Intangible assets, finite-lived					5,160
Other Acquisitions | Non-competition agreements
Intangible assets:
Intangible assets, finite-lived					$ 55
Total Acquisition
Business Combinations
Number of business combination transactions | item					4
Purchase consideration:
Cash					$ 204,074
Issuance of common stock					24,793
Common stock consideration payable					9,014
Contingent consideration - equity-classified					6,685
Contingent consideration - liability-classified					1,737
Total purchase consideration:					246,303
Assets:
Cash, cash equivalents and restricted cash					25,393
Current assets					252,880
Property and equipment					3,694
Intangible assets:
Goodwill					142,750
Other non-current assets					56,190
Total assets acquired					563,716
Current liabilities					(297,197)
Long-term liabilities					(12,018)
Deferred tax liabilities, net					(8,198)
Net assets acquired					246,303
Total Acquisition | Insurance licenses
Intangible assets:
Intangible assets, indefinite					4,960
Total Acquisition | Customer relationships
Intangible assets:
Intangible assets, finite-lived					39,950
Total Acquisition | Acquired technology
Intangible assets:
Intangible assets, finite-lived					7,395
Total Acquisition | Trademarks and tradenames
Intangible assets:
Intangible assets, finite-lived					20,185
Total Acquisition | Non-competition agreements
Intangible assets:
Intangible assets, finite-lived					185
Total Acquisition | Value of business acquired
Intangible assets:
Intangible assets, finite-lived					400
Total Acquisition | Renewal rights
Intangible assets:
Intangible assets, finite-lived					$ 9,734