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v3.23.2

Segment Information - Summary of Premiums Written and Earned by Segment (Details) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2023 | Jun. 30, 2022 | Jun. 30, 2023 | Jun. 30, 2022
Segment Reporting Information [Line Items] |  |  |  |
Net premiums earned | $ 1,034,469 | $ 987,512 | $ 2,039,173 | $ 1,950,062
Direct premiums written | 1,139,500 | 1,034,100 | 2,158,000 | 2,052,300
Private passenger automobile |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Net premiums earned | 674,700 | 666,000 | 1,335,300 | 1,325,300
Direct premiums written | 698,500 | 653,800 | 1,332,800 | 1,335,000
Homeowners |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Net premiums earned | 233,900 | 205,900 | 456,400 | 397,900
Direct premiums written | 294,500 | 251,800 | 536,100 | 462,100
Commercial automobile |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Net premiums earned | 72,100 | 66,100 | 141,200 | 130,600
Direct premiums written | 82,700 | 69,800 | 162,700 | 141,400
Other |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Net premiums earned | 53,800 | 49,500 | 106,300 | 96,300
Direct premiums written | 63,800 | 58,700 | 126,400 | 113,800
Property & Casualty |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Net premiums earned | 1,027,270 | 980,304 | 2,024,832 | 1,935,722
Direct premiums written | 1,132,216 | 1,025,749 | 2,144,453 | 2,037,134
Property & Casualty | Private passenger automobile |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Net premiums earned | 674,700 | 666,000 | 1,335,300 | 1,325,300
Direct premiums written | 698,500 | 653,800 | 1,332,800 | 1,335,000
Property & Casualty | Homeowners |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Net premiums earned | 233,900 | 205,900 | 456,400 | 397,900
Direct premiums written | 294,500 | 251,800 | 536,100 | 462,100
Property & Casualty | Commercial automobile |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Net premiums earned | 72,100 | 66,100 | 141,200 | 130,600
Direct premiums written | 82,700 | 69,800 | 162,700 | 141,400
Property & Casualty | Other |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Net premiums earned | 46,600 | 42,300 | 91,900 | 81,900
Direct premiums written | 56,500 | 50,300 | 112,900 | 98,600
Other |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Net premiums earned | 7,200 | 7,200 | 14,400 | 14,400
Direct premiums written | 7,300 | 8,400 | 13,500 | 15,200
Other | Private passenger automobile |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Net premiums earned | 0 | 0 |  | 0
Direct premiums written | 0 | 0 |  | 0
Other | Homeowners |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Net premiums earned | 0 | 0 |  | 0
Direct premiums written | 0 | 0 |  | 0
Other | Commercial automobile |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Net premiums earned | 0 | 0 |  | 0
Direct premiums written | 0 | 0 |  | 0
Other | Other |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Net premiums earned | 7,200 | 7,200 | 14,400 | 14,400
Direct premiums written | $ 7,300 | $ 8,400 | $ 13,500 | $ 15,200

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- Definition Amount, before premiums ceded to other entities and premiums assumed by the entity, of premiums written. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 605 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (b)(1) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479655/944-605-50-1 + Details
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- Definition Amount, after premiums ceded to other entities and premiums assumed by the entity, of premiums earned. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 235 -Name Accounting Standards Codification -Section S99 -Paragraph 2 -Subparagraph (SX 210.12-17(Column E)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480149/944-235-S99-2 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 605 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (c)(3) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479655/944-605-50-1 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04(13)(c)) -SubTopic 220 -Topic 942 -Publisher FASB -URI https://asc.fasb.org//1943274/2147483589/942-220-S99-1 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04(1)) -SubTopic 220 -Topic 944 -Publisher FASB -URI https://asc.fasb.org//1943274/2147483586/944-220-S99-1 + Details
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