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v3.25.2

Segment Information - Summary of Premiums Written and Earned by Segment (Details) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2025 | Jun. 30, 2024 | Jun. 30, 2025 | Jun. 30, 2024
Segment Reporting Information [Line Items] |  |  |  |
Net premiums earned | $ 1,366,738 | $ 1,236,024 | $ 2,649,808 | $ 2,402,703
Operating Segments |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Net premiums earned | 1,366,700 | 1,236,000 | 2,649,800 | 2,402,700
Direct premiums written | 1,485,000 | 1,387,300 | 2,930,400 | 2,688,400
Private passenger automobile | Operating Segments |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Net premiums earned | 887,400 | 799,600 | 1,746,000 | 1,553,900
Direct premiums written | 881,500 | 847,600 | 1,788,000 | 1,673,100
Homeowners | Operating Segments |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Net premiums earned | 316,900 | 283,600 | 572,900 | 550,500
Direct premiums written | 434,500 | 361,900 | 778,700 | 664,000
Commercial automobile | Operating Segments |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Net premiums earned | 95,900 | 94,200 | 191,200 | 183,400
Direct premiums written | 93,900 | 98,800 | 200,400 | 202,800
Other | Operating Segments |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Net premiums earned | 66,500 | 58,600 | 139,700 | 114,900
Direct premiums written | 75,100 | 79,000 | 163,300 | 148,500
Property & Casualty |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Net premiums earned | 1,359,342 | 1,228,696 | 2,635,100 | 2,388,065
Direct premiums written | 1,477,169 | 1,380,511 | 2,915,636 | 2,674,986
Property & Casualty | Operating Segments |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Net premiums earned | 1,359,300 | 1,228,700 | 2,635,100 | 2,388,100
Direct premiums written | 1,477,200 | 1,380,500 | 2,915,600 | 2,675,000
Property & Casualty | Private passenger automobile | Operating Segments |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Net premiums earned | 887,400 | 799,600 | 1,746,000 | 1,553,900
Direct premiums written | 881,500 | 847,600 | 1,788,000 | 1,673,100
Property & Casualty | Homeowners | Operating Segments |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Net premiums earned | 316,900 | 283,600 | 572,900 | 550,500
Direct premiums written | 434,500 | 361,900 | 778,700 | 664,000
Property & Casualty | Commercial automobile | Operating Segments |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Net premiums earned | 95,900 | 94,200 | 191,200 | 183,400
Direct premiums written | 93,900 | 98,800 | 200,400 | 202,800
Property & Casualty | Other | Operating Segments |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Net premiums earned | 59,100 | 51,300 | 125,000 | 100,300
Direct premiums written | 67,300 | 72,200 | 148,500 | 135,100
Other | Operating Segments |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Net premiums earned | 7,400 | 7,300 | 14,700 | 14,600
Direct premiums written | 7,800 | 6,800 | 14,800 | 13,400
Other | Private passenger automobile | Operating Segments |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Net premiums earned | 0 | 0 | 0 | 0
Direct premiums written | 0 | 0 | 0 | 0
Other | Homeowners | Operating Segments |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Net premiums earned | 0 | 0 | 0 | 0
Direct premiums written | 0 | 0 | 0 | 0
Other | Commercial automobile | Operating Segments |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Net premiums earned | 0 | 0 | 0 | 0
Direct premiums written | 0 | 0 | 0 | 0
Other | Other | Operating Segments |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Net premiums earned | 7,400 | 7,300 | 14,700 | 14,600
Direct premiums written | $ 7,800 | $ 6,800 | $ 14,800 | $ 13,400

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