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v3.25.3

Operating Segment Information - Summary of Revenue by Major Product Type (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2025 | Sep. 30, 2024 | Sep. 30, 2025 | Sep. 30, 2024
Segment Reporting |  |  |  |
Net premiums earned | $ 407,695 | $ 389,489 | $ 1,207,944 | $ 1,129,230
Casualty Segment |  |  |  |
Segment Reporting |  |  |  |
Net premiums earned | 243,508 | 219,638 | 707,194 | 627,014
Casualty Segment | Commercial excess and personal umbrella |  |  |  |
Segment Reporting |  |  |  |
Net premiums earned | 115,132 | 91,434 | 327,252 | 257,455
Casualty Segment | Commercial transportation |  |  |  |
Segment Reporting |  |  |  |
Net premiums earned | 31,190 | 32,067 | 91,464 | 88,691
Casualty Segment | General liability |  |  |  |
Segment Reporting |  |  |  |
Net premiums earned | 28,690 | 26,316 | 82,997 | 77,832
Casualty Segment | Professional services |  |  |  |
Segment Reporting |  |  |  |
Net premiums earned | 27,431 | 26,281 | 80,641 | 77,366
Casualty Segment | Small commercial |  |  |  |
Segment Reporting |  |  |  |
Net premiums earned | 19,627 | 20,074 | 59,542 | 57,870
Casualty Segment | Executive products |  |  |  |
Segment Reporting |  |  |  |
Net premiums earned | 6,043 | 6,261 | 17,507 | 17,624
Casualty Segment | Other casualty |  |  |  |
Segment Reporting |  |  |  |
Net premiums earned | 15,395 | 17,205 | 47,791 | 50,176
Property Segment |  |  |  |
Segment Reporting |  |  |  |
Net premiums earned | 126,689 | 133,266 | 389,897 | 396,774
Property Segment | Commercial property |  |  |  |
Segment Reporting |  |  |  |
Net premiums earned | 72,853 | 85,814 | 232,541 | 260,819
Property Segment | Marine |  |  |  |
Segment Reporting |  |  |  |
Net premiums earned | 40,058 | 37,618 | 118,784 | 107,255
Property Segment | Other property |  |  |  |
Segment Reporting |  |  |  |
Net premiums earned | 13,778 | 9,834 | 38,572 | 28,700
Surety Segment |  |  |  |
Segment Reporting |  |  |  |
Net premiums earned | 37,498 | 36,585 | 110,853 | 105,442
Surety Segment | Transactional |  |  |  |
Segment Reporting |  |  |  |
Net premiums earned | 13,268 | 12,488 | 39,024 | 36,904
Surety Segment | Commercial |  |  |  |
Segment Reporting |  |  |  |
Net premiums earned | 12,700 | 12,477 | 37,898 | 35,802
Surety Segment | Contract |  |  |  |
Segment Reporting |  |  |  |
Net premiums earned | $ 11,530 | $ 11,620 | $ 33,931 | $ 32,736

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