Reserve for Losses and Loss Adjustment Expenses - Narrative (Details) - USD ($) $ in Thousands			12 Months Ended
	Nov. 11, 2024	Jul. 02, 2024	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Insurance [Abstract]
Allowance for credit losses on reinsurance recoverables			$ 1,600	$ 1,200	$ 660
Reserve For Losses And Loss Adjustment Expenses [Line Items]
Development on prior year loss adverse (favorable) reserves			(1,549)	76,079	31,636
Net incurred losses and loss adjustment expenses			427,204	554,374	500,157
Reduction in pre-tax income			(50,543)	71,120	(86,914)
Excess and Surplus Lines
Reserve For Losses And Loss Adjustment Expenses [Line Items]
Development on prior year loss adverse (favorable) reserves			(5,000)	76,700	32,600
Excess and Surplus Lines | E&S Top Up ADC
Reserve For Losses And Loss Adjustment Expenses [Line Items]
Development on prior year loss adverse (favorable) reserves			51,400
Reinsure percentage	100.00%
Reinsurance, aggregate coverage limit	$ 75,000
Payments for reinsurance	52,800			52,800
Reduction in pre-tax income	52,800
Reinsurance, amount remaining			23,600
Excess and Surplus Lines | Commercial Auto LPT And E&S ADC
Reserve For Losses And Loss Adjustment Expenses [Line Items]
Development on prior year loss adverse (favorable) reserves			27,197	51,799	64,403
Net incurred losses and loss adjustment expenses			27,200
Excess and Surplus Lines | E&S ADC
Reserve For Losses And Loss Adjustment Expenses [Line Items]
Development on prior year loss adverse (favorable) reserves			35,045	48,748	0
Initial loss on contract			52,200
Reinsure excess amount		$ 716,600
Reinsurance, aggregate coverage limit	$ 1,183,700	467,100
Payments for reinsurance		$ 313,200		313,200
Excess and Surplus Lines | E&S ADC | State National
Reserve For Losses And Loss Adjustment Expenses [Line Items]
Reinsure percentage		85.00%
Reinsurance, aggregate coverage limit		$ 397,000
Excess and Surplus Lines | Commercial Auto LPT | Commercial Auto LPT
Reserve For Losses And Loss Adjustment Expenses [Line Items]
Development on prior year loss adverse (favorable) reserves			(7,848)	3,051	64,403
Cumulative amounts ceded under loss portfolio transfer			451,400	459,300	456,200
Specialty Admitted Insurance
Reserve For Losses And Loss Adjustment Expenses [Line Items]
Development on prior year loss adverse (favorable) reserves			$ 3,500	$ (607)	$ (972)