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Investment Securities (Details 3) (Level 3 Inputs, USD $) In Millions, unless otherwise specified | 3 Months Ended
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Mar. 31, 2012 | Mar. 31, 2011
Investment securities |  |
Total pre-tax gains (losses) included in earnings attributable to unrealized investment gains (losses) for Level 3 investments | $ 15.5 | $ (7.6)
Fixed maturity investments. |  |
Investment securities |  |
Total pre-tax gains (losses) included in earnings attributable to unrealized investment gains (losses) for Level 3 investments | 7.8 | 1.9
Common equity securities |  |
Investment securities |  |
Total pre-tax gains (losses) included in earnings attributable to unrealized investment gains (losses) for Level 3 investments | 0.5 | (1.8)
Other long-term investments |  |
Investment securities |  |
Total pre-tax gains (losses) included in earnings attributable to unrealized investment gains (losses) for Level 3 investments | $ 7.2 | $ (7.7)

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- Definition The aggregate increase (decrease) in the market value of unsold investments whose gains (losses) are included in earnings. + References No definition available. + Details
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