v3.26.3
Related-Party Transactions - Schedule of Reinsurance Agreement (Details) - USD ($)
$ in Thousands
 3 Months Ended 9 Months Ended
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
Dec. 31, 2025
Related Party Transaction [Line Items]          
Earned premium, net $ 265,113 $ 187,039 $ 756,711 $ 534,179  
Total revenue 354,242 391,417 1,020,894 1,099,062  
Losses and loss adjustment expenses, net 90,261 78,626 298,889 224,969  
Policy acquisition costs, net (62,214) (87,411) (247,777) (247,682)  
Underwriting and other insurance expenses 66,716 1,500 189,251 4,079  
Total expenses (312,843) (378,080) (998,200) (999,580)  
Accounts receivable 27,519   27,519   $ 98,872
Premiums receivable 125,223   125,223   180,529
Reinsurance recoverables 17,061   17,061   15,296
Other assets 223,556   223,556   207,986
TOTAL ASSETS 2,279,434   2,279,434   2,093,976
Accounts payable and accrued expenses 122,101   122,101   111,947
Losses payable and reserves for unpaid losses and loss adjustment expenses 232,132   232,132   264,204
Due to insurers 19,047   19,047   94,930
Other liabilities 101,491   101,491   61,684
TOTAL LIABILITIES 1,527,215   1,527,215   1,346,950
Markel | Reinsurance Agreement | Affiliated Entity          
Related Party Transaction [Line Items]          
Earned premium, net 277,440 191,315 783,230 549,289  
Commission and fee revenue 1,649 122,386 5,172 343,813  
Total revenue 279,089 313,701 788,402 893,102  
Losses and loss adjustment expenses, net 86,698 78,194 283,931 232,703  
Policy acquisition costs, net 47,561 88,998 222,987 253,333  
Underwriting and other insurance expenses 1,634 0 4,376 0  
Total expenses (135,893) (167,192) (511,294) (486,036)  
Accounts receivable 1,348   1,348   1,321
Premiums receivable 0   0   174,169
Reinsurance recoverables 1,576   1,576   1,958
Other assets 3,780   3,780   0
TOTAL ASSETS 6,704   6,704   177,448
Accounts payable and accrued expenses 859   859   0
Losses payable and reserves for unpaid losses and loss adjustment expenses 0   0   247,758
Due to insurers 4,514   4,514   88,888
Ceding commissions payable 0   0   83,494
Other liabilities 2,988   2,988   2,470
TOTAL LIABILITIES 8,361   8,361   422,610
State Farm | Reinsurance Agreement | Affiliated Entity          
Related Party Transaction [Line Items]          
Earned premium, net 5,461 4,923 16,135 14,114  
Losses and loss adjustment expenses, net 1,639 1,577 5,111 9,084  
Policy acquisition costs, net (2,839) (2,559) (8,390) (7,339)  
Total expenses (4,478) $ (4,136) (13,501) $ (16,423)  
Reinsurance recoverables 6,934   6,934   6,668
Other assets 6,223   6,223   2,716
TOTAL ASSETS 13,157   13,157   9,384
Other liabilities 11,966   11,966   5,224
TOTAL LIABILITIES $ 11,966   $ 11,966   $ 5,224