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Segments of Operations - Earnings before income taxes by segment and sub-segment (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021
Segment Reporting Information [Line Items] |  |  |
Earnings before realized gains (losses) and income taxes | $ 1,113 | $ 1,239 | $ 1,221
Realized gains (losses) on securities | (36) | (116) | 110
Realized gains (losses) on subsidiaries | (4) | 0 | 4
Earnings from continuing operations before income taxes | 1,073 | 1,123 | 1,335
Property and casualty insurance |  |  |
Segment Reporting Information [Line Items] |  |  |
Property and casualty insurance underwriting | 631 | 776 | 733
Investment and other income, net | 673 | 643 | 657
Earnings before realized gains (losses) and income taxes | 1,304 | 1,419 | 1,390
Other |  |  |
Segment Reporting Information [Line Items] |  |  |
Earnings before realized gains (losses) and income taxes | (191) | (180) | (220)
Other | Continuing operations |  |  |
Segment Reporting Information [Line Items] |  |  |
Earnings from real-estate related investments, net of DAC | 0 | 0 | 51
Property and transportation | Property and casualty insurance |  |  |
Segment Reporting Information [Line Items] |  |  |
Property and casualty insurance underwriting | 184 | 208 | 279
Specialty casualty | Property and casualty insurance |  |  |
Segment Reporting Information [Line Items] |  |  |
Property and casualty insurance underwriting | 375 | 500 | 377
Specialty financial | Property and casualty insurance |  |  |
Segment Reporting Information [Line Items] |  |  |
Property and casualty insurance underwriting | 110 | 114 | 96
Other specialty | Property and casualty insurance |  |  |
Segment Reporting Information [Line Items] |  |  |
Property and casualty insurance underwriting | (36) | (42) | (15)
Other lines | Property and casualty insurance |  |  |
Segment Reporting Information [Line Items] |  |  |
Property and casualty insurance underwriting | $ (2) | $ (4) | $ (4)

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