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Investment Securities (Investments In Private Equity Funds Subject to Lock-Up Periods) (Details) - USD ($) $ in Millions | 3 Months Ended
--- | ---
Mar. 31, 2016 | Mar. 31, 2015
Schedule of Trading Securities and Other Trading Assets [Line Items] |  |
Net Income (Loss) Attributable to Noncontrolling Interest | $ 6.3 | $ (7.3)
Private equity funds |  |
Schedule of Trading Securities and Other Trading Assets [Line Items] |  |
Other long-term investments | 94.9 |
1-3 years | Private equity funds |  |
Schedule of Trading Securities and Other Trading Assets [Line Items] |  |
Other long-term investments | 29.2 |
3-5 years | Private equity funds |  |
Schedule of Trading Securities and Other Trading Assets [Line Items] |  |
Other long-term investments | 3.9 |
5-10 years | Private equity funds |  |
Schedule of Trading Securities and Other Trading Assets [Line Items] |  |
Other long-term investments | 61.8 |
Greater than 10 years | Private equity funds |  |
Schedule of Trading Securities and Other Trading Assets [Line Items] |  |
Other long-term investments | $ 0.0 |

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