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Investments in Unconsolidated Entities (Details) - White Mountains - USD ($) $ in Millions | Sep. 30, 2019 | Dec. 31, 2018
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Investments in unconsolidated affiliates |  |
Other Investments | $ 773.7 | $ 325.6
Equity method eligible private equity securities, at fair value |  |
Investments in unconsolidated affiliates |  |
Other Investments | 673.2 | 269.7
Other unconsolidated investments |  |
Investments in unconsolidated affiliates |  |
Other Investments | $ 100.5 | $ 55.9

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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
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- Details
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