Unpaid Loss and Loss Adjustment Expense - Activity in the Liability for Unpaid Loss and LAE (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Unpaid loss and LAE as of January 1	$ 298.1	$ 262.3	$ 256.2
Less: Reinsurance recoverable	149.5	120.2	124.6
Net unpaid loss and LAE as of January 1	148.6	142.1	131.6
Add: Incurred losses and LAE, net of reinsurance, related to:
Current year	377.4	287.0	286.2
Prior years	(30.4)	(10.0)	(5.8)
Total incurred	347.0	277.0	280.4
Deduct: Paid losses and LAE, net of reinsurance, related to:
Current year	252.2	195.4	189.4
Prior years	74.1	74.9	80.5
Total paid	326.3	270.3	269.9
Unpaid loss and LAE, net of reinsurance recoverable, as of December 31	169.3	148.6	142.1
Reinsurance recoverable at December 31	133.8	149.5	120.2
Unpaid loss and LAE, gross of reinsurance recoverable, as of December 31	$ 303.1	$ 298.1	$ 262.3