Other Liabilities and Accrued Expenses - Summary (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Other Liabilities Disclosure [Abstract]
Lease liabilities	$ 29.7	$ 35.2
Ceded commission payable	12.6	0.0
Uncertain tax position	11.2	8.1
Employee compensation	6.9	12.8
Accrued professional fees	5.6	5.5
Accrued advertising costs	5.0	6.8
Advance premium	4.3	2.1
Premium taxes payable	4.0	6.2
Accrued hosting and software	1.4	2.0
Income taxes payable	0.9	0.6
Warrant liability	0.0	0.3
Other payables	11.5	4.9
Total	$ 93.1	$ 84.5