Supplemental Disclosures of Cash Flow Information and Non-Cash Financing and Investing Activities - Summary of Significant Non-Cash Investing and Financing Activities (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Significant non-cash investing and financing activities
Other payable issued for agency acquisitions and purchased customer accounts	$ 2.3	$ 1.2
Estimated acquisition earn-out payables issued for agency acquisitions	$ 40.2	$ 16.9