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Investments in Unconsolidated Affiliates (Details) (USD $) In Millions, unless otherwise specified | Dec. 31, 2011 | Dec. 31, 2010 | Dec. 31, 2009 | Dec. 31, 2008
--- | --- | --- | --- | ---
Investments in unconsolidated affiliates |  |  |  |
Total investments in unconsolidated affiliates | $ 275.3 | $ 389.7 |  |
Symetra |  |  |  |
Investments in unconsolidated affiliates |  |  |  |
Total investments in unconsolidated affiliates | 273.6 | 387.5 | 307.7 | 81.3
Symetra | Common shareholders' equity. |  |  |  |
Investments in unconsolidated affiliates |  |  |  |
Total investments in unconsolidated affiliates | 261.0 | 350.4 | 269.2 | 54.0
Symetra | Warrants |  |  |  |
Investments in unconsolidated affiliates |  |  |  |
Total investments in unconsolidated affiliates | 12.6 | 37.1 | 38.5 | 27.3
Pentelia Capital Management |  |  |  |
Investments in unconsolidated affiliates |  |  |  |
Total investments in unconsolidated affiliates | $ 1.7 | $ 2.2 |  |

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- Definition Total investments in (A) companies that are accounted for using the equity method and (B) warrants to acquire additional shares of an unconsolidated affiliate that are carried at fair value. + References No definition available. + Details
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