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Segments of Operations - Narrative (Details) $ in Millions | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2020 USD ($) | Jun. 30, 2019 USD ($) | Jun. 30, 2020 USD ($) segment | Jun. 30, 2019 USD ($)
Segment Reporting Information [Line Items] |  |  |  |  |  |  |
Number of segments | segment |  |  |  |  | 3 |  |
Total premiums earned |  | $ 1,184 |  | $ 1,200 | $ 2,393 |  | $ 2,373
Net investment income |  | 468 | [1] | 580 | 1,012 | [1] | 1,122
Property and Casualty Insurance |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |
Total premiums earned |  | 1,184 |  | 1,200 | 2,393 |  | 2,373
Net investment income |  | 72 | [2] | 124 | 165 | [2] | 228
Property and casualty insurance underwriting |  | 9 |  | 59 | 96 |  | 146
Investment and other income, net |  | 65 | [3] | 115 | 149 | [3] | 210
Other lines | Property and Casualty Insurance |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |
Total premiums earned | [4] | 61 |  | 0 | 132 |  | 0
Property and casualty insurance underwriting | [5] | (45) |  | (1) | (47) |  | (2)
Neon Capital Limited |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |
Net investment income |  |  |  |  | (6) |  |
Neon Capital Limited | Maximum |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |
Net investment income |  | 1 |  |  |  |  |
Neon Capital Limited | Other lines | Property and Casualty Insurance |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |
Total premiums earned |  |  |  | 89 |  |  | 177
Net investment income |  |  |  |  | (6) |  |
Property and casualty insurance underwriting |  | (43) |  | $ (4) | 44 |  | $ (14)
Investment and other income, net |  | (1) |  |  | $ (10) |  |
Neon Capital Limited | Other lines | Property and Casualty Insurance | Maximum |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |
Net investment income |  | $ 1 |  |  |  |  |
[1] | Net investment income in the second quarter and first six months of 2020 includes income of less than $1 million and losses of $6 million, respectively, on investments held by the companies that comprise the Neon exited lines due primarily to the $7 million loss in first quarter of 2020 recorded on equity securities that are carried at fair value through net investment income.
[2] | Includes income of less than $1 million for the second quarter of 2020 and a loss of $6 million in the Neon exited lines in the first six months of 2020 (primarily from the change in fair value of equity securities).
[3] | Includes $1 million and $10 million in the second quarter and first six months of 2020, respectively, in net expenses from the Neon exited lines, before noncontrolling interest.
[4] | Represents premiums earned in the Neon exited lines during the second quarter and first six months of 2020. Neon’s $89 million and $177 million in earned premiums during the second quarter and first six months of 2019, respectively, are included in the Specialty casualty sub-segment.
[5] | Includes an underwriting loss of $43 million in the second quarter of 2020 and $44 million in the first six months of 2020 in the Neon exited lines. Neon’s $4 million and $14 million underwriting losses in the second quarter and first six months of 2019, respectively, are included in the Specialty casualty sub-segment.

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