Other Liabilities and Accrued Expenses (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Other Liabilities Disclosure [Abstract]
Lease liabilities (Note 22)	$ 28.2	$ 35.2
Ceding commission payable	13.9	0.0
Uncertain tax position	13.3	8.1
Employee compensation	8.4	12.8
Accrued advertising costs	6.2	6.8
Premium taxes payable	5.9	6.2
Accrued professional fees	5.0	5.5
Advance premium	3.4	2.1
Accrued hosting and software	1.8	2.0
Income taxes payable	1.2	0.6
Warrant liability	0.0	0.3	$ 0.0
Other payables	12.2	4.9
Total	$ 99.5	$ 84.5
Operating lease, liability, statement of financial position	Total	Total