Other Reinsurance (Details) $ in Millions	12 Months Ended
Other Reinsurance (Details) $ in Millions	Dec. 31, 2025 USD ($) employees director	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)
Effects of Reinsurance [Line Items]
Reinsurance recoverables	$ 78.1	$ 78.7
Ceded earned premiums	17.3	33.1	$ 32.7
Assumed earned premiums	(1.7)	10.5	29.7
Short duration policies
Effects of Reinsurance [Line Items]
Reinsurance recoverables	27.2	26.0
Long-duration policies
Effects of Reinsurance [Line Items]
Reinsurance recoverables	50.9	52.7
Catastrophe Reinsurance
Effects of Reinsurance [Line Items]
Ceded earned premiums	1.3	16.4	16.3
Non-Catastrophe Reinsurance
Effects of Reinsurance [Line Items]
Assumed earned premiums	$ 9.8	21.8	42.9
Capitol County Mutual Fire Insurance Company
Effects of Reinsurance [Line Items]
Number of employee board members \| employees	7
Number of board of director members \| director	7
Old Reliable Casualty Company
Effects of Reinsurance [Line Items]
Number of employee board members \| employees	10
Number of board of director members \| director	10
Capitol County Mutual Fire Insurance Company
Effects of Reinsurance [Line Items]
Assumed earned premiums	$ 9.2	10.5	10.4
Capitol County Mutual Fire Insurance Company \| Trinity
Effects of Reinsurance [Line Items]
Percentage of written business assumed	100.00%
Old Reliable Casualty Company
Effects of Reinsurance [Line Items]
Assumed earned premiums	$ 2.2	$ 2.3	$ 2.7
Old Reliable Casualty Company \| Trinity
Effects of Reinsurance [Line Items]
Percentage of written business assumed	100.00%