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Property and Casualty Insurance Reserves - Narrative (Details) - USD ($) $ in Millions | 6 Months Ended
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Jun. 30, 2025 | Jun. 30, 2024
Liability for Claims and Claims Adjustment Expense [Line Items] |  |
Incurred Losses and LAE Related to Prior Years | $ 14.4 | $ 17.0
Non-Core Operations |  |
Liability for Claims and Claims Adjustment Expense [Line Items] |  |
Incurred Losses and LAE Related to Prior Years |  | 11.9
Commercial Automobile |  |
Liability for Claims and Claims Adjustment Expense [Line Items] |  |
Incurred Losses and LAE Related to Prior Years | 24.0 |
Specialty Personal Automobile |  |
Liability for Claims and Claims Adjustment Expense [Line Items] |  |
Incurred Losses and LAE Related to Prior Years | $ (10.1) | 7.7
Commercial Automobile |  |
Liability for Claims and Claims Adjustment Expense [Line Items] |  |
Incurred Losses and LAE Related to Prior Years |  | $ (2.6)

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- Definition Amount, after effects of reinsurance, of expense (reversal of expense) for claims incurred in prior reporting periods and related claims settlement costs. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 55 -Paragraph 7 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480046/944-40-55-7 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480081/944-40-50-3 + Details
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