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v3.26.1

Segments of Operations - Revenues by segment and sub-segment (Details) - USD ($) $ in Millions | 3 Months Ended
--- | ---
Mar. 31, 2026 | Mar. 31, 2025
Segment Reporting Information [Line Items] |  |
Net earned premiums | $ 1,609 | $ 1,580
Net investment income | 187 | 173
Other income | 29 | 27
Revenues before realized gains (losses) | 1,872 | 1,853
Realized gains (losses) on securities | (18) | 3
Total revenues | 1,854 | 1,856
Operating segments | Property and Casualty Insurance |  |
Segment Reporting Information [Line Items] |  |
Net earned premiums | 1,609 | 1,580
Net investment income | 168 | 170
Other income | 4 | 3
Revenues before realized gains (losses) | 1,781 | 1,753
Operating segments | Property and Casualty Insurance | Property and transportation |  |
Segment Reporting Information [Line Items] |  |
Net earned premiums | 526 | 500
Operating segments | Property and Casualty Insurance | Specialty casualty |  |
Segment Reporting Information [Line Items] |  |
Net earned premiums | 799 | 794
Operating segments | Property and Casualty Insurance | Specialty financial |  |
Segment Reporting Information [Line Items] |  |
Net earned premiums | 284 | 286
Operating segments | Other |  |
Segment Reporting Information [Line Items] |  |
Revenues before realized gains (losses) | $ 91 | $ 100

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