Related-Party Transactions - Schedule of Reinsurance Agreement (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025	Dec. 31, 2025
Related Party Transaction [Line Items]
Earned premium, net	$ 239,642	$ 169,355
Total revenue	311,830	328,336
Losses and loss adjustment expenses, net	97,919	71,130
Policy acquisition costs, net	99,949	79,467
Policy acquisition costs, net	(101,922)	(77,333)
Underwriting and other insurance expenses	59,588	1,357
Total expenses	332,767	295,554
Accounts receivable	27,993		$ 98,872
Premiums receivable	92,446		180,529
Deferred acquisition costs, net	143,552		179,224
Reinsurance recoverables	11,863		15,296
Other assets	228,386		207,986
Prepaid reinsurance premiums	40,405		21,950
TOTAL ASSETS	2,024,593		2,093,976
Accounts payable and accrued expenses	85,847		111,947
Losses payable and reserves for unpaid losses and loss adjustment expenses	203,987		264,204
Due to insurers	14,366		94,930
Other liabilities	106,757		61,684
TOTAL LIABILITIES	1,290,550		1,346,950
Markel | Reinsurance Agreement | Affiliated Entity
Related Party Transaction [Line Items]
Earned premium, net	244,808	175,061
Commission and fee revenue	1,706	93,973
Total revenue	246,514	269,034
Losses and loss adjustment expenses, net	91,506	79,911
Underwriting and other insurance expenses	2,117	0
Total expenses	193,572	159,378
Accounts receivable	1,196		1,321
Premiums receivable	0		174,169
Reinsurance recoverables	1,742		1,958
Other assets	6,155		0
TOTAL ASSETS	9,093		177,448
Accounts payable and accrued expenses	1,200		0
Losses payable and reserves for unpaid losses and loss adjustment expenses	0		247,758
Due to insurers	4,773		88,888
Ceding commissions payable	0		83,494
Other liabilities	2,553		2,470
TOTAL LIABILITIES	8,526		422,610
State Farm | Reinsurance Agreement | Affiliated Entity
Related Party Transaction [Line Items]
Earned premium, net	5,207	4,456
Losses and loss adjustment expenses, net	1,562	6,087
Policy acquisition costs, net	(2,708)	(2,317)
Total expenses	4,270	$ 8,404
Accounts receivable	2,873		2,716
Deferred acquisition costs, net	5,566		5,400
Reinsurance recoverables	4,858		6,668
Prepaid reinsurance premiums	10,704		10,385
TOTAL ASSETS	12,869		14,369
Other liabilities	5,525		5,224
TOTAL LIABILITIES	$ 5,525		$ 5,224