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Segments of Operations - Assets by segment (Details) - USD ($) $ in Millions | Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
--- | --- | --- | ---
Segment Reporting Information [Line Items] |  |  |  |
Total assets |  | $ 70,130 | $ 63,456 | $ 60,658
Property and casualty insurance |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Total assets | [1] | 19,098 | 17,681 | 17,171
Annuity |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Total assets |  | 45,074 | 39,952 | 37,179
Other |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Total assets |  | $ 5,958 | $ 5,823 | $ 6,308
[1] | Not allocable to sub-segments.

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