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Segments of Operations - Earnings before income taxes by segment and sub-segment (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2021 | Sep. 30, 2020 | Sep. 30, 2021 | Sep. 30, 2020
Segment Reporting Information [Line Items] |  |  |  |
Earnings before realized gains (losses) and income taxes | $ 284 | $ 47 | $ 783 | $ 222
Realized gains (losses) on securities | (17) | 23 | 103 | (197)
Realized gains (losses) on subsidiaries | 0 | (30) | 4 | (30)
Earnings (loss) from continuing operations before income taxes | 267 | 40 | 890 | (5)
Property and Casualty Insurance |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Property and casualty insurance underwriting | 168 | 18 | 454 | 114
Investment and other income, net | 161 | 100 | 451 | 249
Earnings before realized gains (losses) and income taxes | 329 | 118 | 905 | 363
Other |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Earnings before realized gains (losses) and income taxes | (45) | (74) | (173) | (152)
Other | Continuing operations | Real estate-related investments |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Earnings from real-estate related investments, net of DAC | 0 | 3 | 51 | 11
Specialty Property and transportation | Property and Casualty Insurance |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Property and casualty insurance underwriting | 45 | 47 | 163 | 107
Specialty casualty | Property and Casualty Insurance |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Property and casualty insurance underwriting | 110 | 53 | 237 | 132
Specialty financial | Property and Casualty Insurance |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Property and casualty insurance underwriting | 26 | 13 | 72 | 30
Other specialty | Property and Casualty Insurance |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Property and casualty insurance underwriting | (12) | (9) | (16) | (22)
Other lines | Property and Casualty Insurance |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Property and casualty insurance underwriting | $ (1) | $ (86) | $ (2) | $ (133)

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