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Segments of Operations - Assets by segment and sub-segment (Details) - USD ($) $ in Millions | Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016
--- | --- | --- | ---
Segment Reporting Information [Line Items] |  |  |  |
Total assets |  | $ 63,456 | $ 60,658 | $ 55,072
Property and casualty insurance |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Total assets | [1] | 17,681 | 17,171 | 15,574
Annuity |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Total assets |  | 39,952 | 37,179 | 33,409
Other |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Total assets |  | $ 5,823 | $ 6,308 | $ 6,089
[1] | Not allocable to sub-segments.

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