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Investment Securities (Hedge Funds and Private Equity Funds) (Details) (USD $) In Millions, unless otherwise specified |  |  |  | 9 Months Ended |  |
--- | --- | --- | --- | --- | --- | ---
Sep. 30, 2014 | Dec. 31, 2013 | Sep. 30, 2014 Hedge funds fund | Sep. 30, 2014 Private equity funds fund | Sep. 30, 2014 Hedge and private equity funds included in other long-term investments | Sep. 30, 2014 Prospector Offshore Fund Ltd [Member] | Sep. 30, 2014 Prospector Turtle Fund [Member] | Sep. 30, 2014 Prospector Funds [Member] | Dec. 31, 2013 Prospector Funds [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items] |  |  |  |  |  |  |  |  |
Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage |  |  |  |  |  | 67.00% | 69.00% |  |
Other Investments | $ 320.9 | $ 288.9 |  |  |  |  |  | $ 95.4 | $ 112.4
Largest single fund investment |  |  |  |  | 19.5 |  |  |  |
Number of investments |  |  | 14 | 32 |  |  |  |  |
Variable Interest Entity, Consolidated, Carrying Amount, Assets |  |  |  |  |  |  |  | 223.5 | 249.2
Variable Interest Entity, Consolidated, Carrying Amount, Liabilities |  |  |  |  |  |  |  | 82.7 | 90.6
Total non-controlling interests | $ 488.7 | $ 491.9 |  |  |  |  |  | $ 45.4 | $ 46.2

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- Definition Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which is directly or indirectly attributable to that ownership interest in subsidiary equity which is not attributable to the parent (that is, noncontrolling interest, previously referred to as minority interest). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.31) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 27 -Article 5 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 20 -Article 7 + Details
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