Reinsurance - Impact of Reinsurance (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Premium written:
Direct	$ 1,142.0	$ 916.4	$ 730.9
Assumed	29.3	12.6	7.5
Ceded	(407.8)	(513.9)	(389.1)
Net premium written	763.5	415.1	349.3
Premium earned:
Direct	1,026.8	815.9	667.2
Assumed	24.0	11.4	5.1
Ceded	(514.5)	(456.7)	(357.1)
Net premium earned	536.3	370.6	315.2
Loss and LAE incurred:
Direct	650.2	593.3	563.4
Assumed	21.8	11.7	6.0
Ceded	(325.0)	(328.0)	(289.0)
Net loss and LAE incurred	$ 347.0	$ 277.0	$ 280.4