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Investments - Net appreciation (decline) recognized in net income (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2019 | Sep. 30, 2018 | Sep. 30, 2019 | Sep. 30, 2018
Investment [Line Items] |  |  |  |
Total | $ 156 | $ 309 | $ 845 | $ 502
Equity securities |  |  |  |
Investment [Line Items] |  |  |  |
Total | 107 | 234 | 736 | 321
Limited partnership interests |  |  |  |
Investment [Line Items] |  |  |  |
Total | $ 49 | $ 75 | $ 109 | $ 181

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- Details
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- Details
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