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v3.25.1

Segment Information - Schedule of Revenue by Segment (Details) - USD ($) $ in Thousands | 3 Months Ended
--- | ---
Mar. 31, 2025 | Mar. 31, 2024
Revenue from External Customer [Line Items] |  |
Net premiums earned | $ 1,158,757 | $ 1,050,944
Miscellaneous income | 5,509 | 7,801
Net investment income earned | 120,691 | 107,849
Net realized and unrealized investment gains (losses) | 229 | (1,635)
Total Investments revenue | 120,920 | 106,214
Total revenues | 1,285,186 | 1,164,959
Standard Commercial Lines |  |
Revenue from External Customer [Line Items] |  |
Net premiums earned | 912,210 | 834,110
Total revenues | 917,070 | 841,244
Standard Personal Lines |  |
Revenue from External Customer [Line Items] |  |
Net premiums earned | 103,655 | 103,846
Total revenues | 104,227 | 104,486
E&S Lines |  |
Revenue from External Customer [Line Items] |  |
Net premiums earned | 142,892 | 112,988
Total revenues | 142,969 | 113,015
General liability | Standard Commercial Lines |  |
Revenue from External Customer [Line Items] |  |
Net premiums earned | 294,687 | 273,415
Commercial automobile | Standard Commercial Lines |  |
Revenue from External Customer [Line Items] |  |
Net premiums earned | 283,585 | 251,720
Commercial property | Standard Commercial Lines |  |
Revenue from External Customer [Line Items] |  |
Net premiums earned | 186,530 | 161,553
Workers compensation | Standard Commercial Lines |  |
Revenue from External Customer [Line Items] |  |
Net premiums earned | 79,036 | 87,777
Businessowners' policies | Standard Commercial Lines |  |
Revenue from External Customer [Line Items] |  |
Net premiums earned | 46,893 | 39,921
Bonds | Standard Commercial Lines |  |
Revenue from External Customer [Line Items] |  |
Net premiums earned | 13,258 | 12,088
Other | Standard Commercial Lines |  |
Revenue from External Customer [Line Items] |  |
Net premiums earned | 8,221 | 7,636
Miscellaneous income | Standard Commercial Lines |  |
Revenue from External Customer [Line Items] |  |
Miscellaneous income | 4,860 | 7,134
Miscellaneous income | Standard Personal Lines |  |
Revenue from External Customer [Line Items] |  |
Miscellaneous income | 572 | 640
Miscellaneous income | E&S Lines |  |
Revenue from External Customer [Line Items] |  |
Miscellaneous income | 77 | 27
Personal automobile | Standard Personal Lines |  |
Revenue from External Customer [Line Items] |  |
Net premiums earned | 52,968 | 56,960
Homeowners | Standard Personal Lines |  |
Revenue from External Customer [Line Items] |  |
Net premiums earned | 47,943 | 44,113
Other | Standard Personal Lines |  |
Revenue from External Customer [Line Items] |  |
Net premiums earned | 2,744 | 2,773
Casualty lines | E&S Lines |  |
Revenue from External Customer [Line Items] |  |
Net premiums earned | 85,119 | 71,638
Property lines | E&S Lines |  |
Revenue from External Customer [Line Items] |  |
Net premiums earned | $ 57,773 | $ 41,350

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