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v3.25.1

Segments of Operations - Revenues by segment and sub-segment (Details) - USD ($) $ in Millions | 3 Months Ended
--- | ---
Mar. 31, 2025 | Mar. 31, 2024
Segment Reporting Information [Line Items] |  |
Net earned premiums | $ 1,580 | $ 1,546
Net investment income | 173 | 198
Other income | 27 | 39
Revenues before realized gains (losses) | 1,853 | 1,892
Realized gains on securities | 3 | 14
Total revenues | 1,856 | 1,906
Operating segments | Property and Casualty Insurance |  |
Segment Reporting Information [Line Items] |  |
Net earned premiums | 1,580 | 1,546
Net investment income | 170 | 205
Other income | 3 | 2
Revenues before realized gains (losses) | 1,753 | 1,753
Operating segments | Property and Casualty Insurance | Property and transportation |  |
Segment Reporting Information [Line Items] |  |
Net earned premiums | 500 | 520
Operating segments | Property and Casualty Insurance | Specialty casualty |  |
Segment Reporting Information [Line Items] |  |
Net earned premiums | 794 | 783
Operating segments | Property and Casualty Insurance | Specialty financial |  |
Segment Reporting Information [Line Items] |  |
Net earned premiums | 286 | 243
Operating segments | Other |  |
Segment Reporting Information [Line Items] |  |
Revenues before realized gains (losses) | $ 100 | $ 139

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