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v3.23.3

Segment Information (Revenue by Segment) (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2023 | Sep. 30, 2022 | Sep. 30, 2023 | Sep. 30, 2022
Segment Reporting Information [Line Items] |  |  |  |
Net premiums earned | $ 981,917 | $ 853,879 | $ 2,826,403 | $ 2,500,601
Other income | 5,181 | 2,933 | 13,919 | 7,499
Net investment income earned | 100,863 | 63,889 | 290,065 | 206,713
Net realized and unrealized investment gains (losses) | (6,880) | (25,681) | (8,962) | (108,913)
Total Investments revenue | 93,983 | 38,208 | 281,103 | 97,800
Total revenues | 1,081,081 | 895,020 | 3,121,425 | 2,605,900
Standard Commercial Lines |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Total revenues | 789,934 | 694,881 | 2,292,007 | 2,040,284
Standard Commercial Lines | General Liability [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Net premiums earned | 261,551 | 225,302 | 759,410 | 667,912
Standard Commercial Lines | Commercial Automobile [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Net premiums earned | 234,622 | 207,129 | 677,060 | 599,340
Standard Commercial Lines | Commercial Property [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Net premiums earned | 152,495 | 128,268 | 429,135 | 371,892
Standard Commercial Lines | Workers Compensation [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Net premiums earned | 81,672 | 81,996 | 254,602 | 250,178
Standard Commercial Lines | Businessowners' Policies [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Net premiums earned | 36,016 | 32,130 | 103,572 | 93,682
Standard Commercial Lines | Bonds Segment [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Net premiums earned | 11,715 | 11,094 | 34,731 | 32,136
Standard Commercial Lines | Other Commercial [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Net premiums earned | 7,257 | 6,518 | 21,142 | 19,003
Standard Commercial Lines | Miscellaneous income |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Other income | 4,606 | 2,444 | 12,355 | 6,141
Standard Personal Lines |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Total revenues | 95,744 | 76,127 | 265,773 | 222,976
Standard Personal Lines | Personal Automobile [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Net premiums earned | 51,906 | 40,746 | 145,050 | 120,414
Standard Personal Lines | Homeowners [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Net premiums earned | 40,175 | 32,619 | 112,090 | 95,436
Standard Personal Lines | Other Personal [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Net premiums earned | 3,088 | 2,273 | 7,069 | 5,768
Standard Personal Lines | Miscellaneous income |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Other income | 575 | 489 | 1,564 | 1,358
E&S Lines |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Total revenues | 101,420 | 85,804 | 282,542 | 244,840
E&S Lines | Casualty Insurance Product Line [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Net premiums earned | 67,718 | 59,640 | 190,686 | 170,305
E&S Lines | Property Insurance [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Net premiums earned | $ 33,702 | $ 26,164 | $ 91,856 | $ 74,535

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