Reserve for Losses and Loss Adjustment Expenses - Schedule of Retroactive Reinsurance (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Retroactive Reinsurance [Line Items]
Deferred retroactive reinsurance gain at beginning of period	$ 57,970
(Favorable) adverse prior year development on subject business	(1,549)	$ 76,079	$ 31,636
Deferred retroactive reinsurance gain at end of period	86,720	57,970
Excess and Surplus Lines
Retroactive Reinsurance [Line Items]
(Favorable) adverse prior year development on subject business	(5,000)	76,700	32,600
Commercial Auto LPT And E&S ADC | Excess and Surplus Lines
Retroactive Reinsurance [Line Items]
Deferred retroactive reinsurance gain at beginning of period	57,970	20,733	15,742
(Favorable) adverse prior year development on subject business	27,197	51,799	64,403
Retroactive reinsurance benefits under the recovery method	1,553	(14,562)	(59,412)
Deferred retroactive reinsurance gain at end of period	86,720	57,970	20,733
Commercial Auto LPT | Excess and Surplus Lines | Commercial Auto LPT
Retroactive Reinsurance [Line Items]
Deferred retroactive reinsurance gain at beginning of period	9,222	20,733	15,742
(Favorable) adverse prior year development on subject business	(7,848)	3,051	64,403
Retroactive reinsurance benefits under the recovery method	1,553	(14,562)	(59,412)
Deferred retroactive reinsurance gain at end of period	2,927	9,222	20,733
E&S ADC | Excess and Surplus Lines
Retroactive Reinsurance [Line Items]
Deferred retroactive reinsurance gain at beginning of period	48,748	0	0
(Favorable) adverse prior year development on subject business	35,045	48,748	0
Retroactive reinsurance benefits under the recovery method	0	0	0
Deferred retroactive reinsurance gain at end of period	$ 83,793	$ 48,748	$ 0