Reinsurance and Policy Benefits and Losses, Claims and Loss Expenses Payable - (Narratives) (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2026	Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Reinsurance Premiums For Insurance Companies By Product Segment [Line Items]
Reinsurance recoverable	$ 30,967	$ 34,566
Repwest [Member]
Reinsurance Premiums For Insurance Companies By Product Segment [Line Items]
Reinsurance recoverable	29,900	32,400	$ 36,200
Increase (decrease) in reinsurance recoverable	$ 10,800	$ 5,600	$ 20,700
Property and Casualty Insurance [Member]
Reinsurance Premiums For Insurance Companies By Product Segment [Line Items]
Reinsurance recoverable				$ 29,887	$ 32,369	$ 36,188	$ 41,329