Business Combinations - Estimated Fair Values of Aggregate Assets and Liabilities Acquired (Details) $ in Thousands	Jun. 30, 2021 USD ($)
Fair Value Of Assets And Liabilities Statement [Line Items]
Cash	$ 46,134
Other current assets	50,373
Fixed assets	558
Goodwill	121,828
Other assets	394
Total assets acquired	275,076
Other current liabilities	(75,394)
Deferred income tax, net	(5,057)
Other liabilities	(13)
Total liabilities assumed	(80,464)
Net assets acquired	194,612
O'Leary Insurances (O'Leary)
Fair Value Of Assets And Liabilities Statement [Line Items]
Cash	45,441
Other current assets	43,683
Fixed assets	546
Goodwill	84,318
Other assets	135
Total assets acquired	215,401
Other current liabilities	(72,683)
Deferred income tax, net	(5,057)
Other liabilities	(13)
Total liabilities assumed	(77,753)
Net assets acquired	137,648
Piper Jordan LLC (Piper)
Fair Value Of Assets And Liabilities Statement [Line Items]
Other current assets	2,047
Fixed assets	9
Goodwill	40,369
Total assets acquired	54,679
Net assets acquired	54,679
Other Acquisitions
Fair Value Of Assets And Liabilities Statement [Line Items]
Cash	693
Other current assets	4,643
Fixed assets	3
Goodwill	(2,859)
Other assets	259
Total assets acquired	4,996
Other current liabilities	(2,711)
Total liabilities assumed	(2,711)
Net assets acquired	2,285
Purchased Customer Accounts
Fair Value Of Assets And Liabilities Statement [Line Items]
Intangible assets	54,894
Purchased Customer Accounts | O'Leary Insurances (O'Leary)
Fair Value Of Assets And Liabilities Statement [Line Items]
Intangible assets	40,459
Purchased Customer Accounts | Piper Jordan LLC (Piper)
Fair Value Of Assets And Liabilities Statement [Line Items]
Intangible assets	12,233
Purchased Customer Accounts | Other Acquisitions
Fair Value Of Assets And Liabilities Statement [Line Items]
Intangible assets	2,202
Non-compete Agreements
Fair Value Of Assets And Liabilities Statement [Line Items]
Intangible assets	895
Non-compete Agreements | O'Leary Insurances (O'Leary)
Fair Value Of Assets And Liabilities Statement [Line Items]
Intangible assets	819
Non-compete Agreements | Piper Jordan LLC (Piper)
Fair Value Of Assets And Liabilities Statement [Line Items]
Intangible assets	21
Non-compete Agreements | Other Acquisitions
Fair Value Of Assets And Liabilities Statement [Line Items]
Intangible assets	$ 55