Unpaid Loss and Loss Adjustment Expense - Unpaid Loss and Loss Adjustment Expenses (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Claims Development [Line Items]
Unpaid Loss and ALAE, net	$ 141.4
Reinsurance recoverable on Unpaid Loss and ALAE, net	120.2	$ 124.6	$ 72.7
Unallocated LAE	0.7
Gross unpaid loss and LAE	262.3	$ 256.2	$ 97.9
Home and renters
Claims Development [Line Items]
Unpaid Loss and ALAE, net	63.4
Reinsurance recoverable on Unpaid Loss and ALAE, net	92.9
Gross unpaid loss and LAE	156.3
Pet
Claims Development [Line Items]
Unpaid Loss and ALAE, net	6.2
Reinsurance recoverable on Unpaid Loss and ALAE, net	7.8
Gross unpaid loss and LAE	14.0
Car
Claims Development [Line Items]
Unpaid Loss and ALAE, net	71.8
Reinsurance recoverable on Unpaid Loss and ALAE, net	19.5
Gross unpaid loss and LAE	$ 91.3