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Investment Securities (Other long-term investments) (Details) (USD $) In Millions, unless otherwise specified | 9 Months Ended |
--- | --- | ---
Sep. 30, 2012 | Dec. 31, 2011
Investment securities |  |
Distributions from Inactive Hedge Funds | $ 3.3 |
Maximum percentage of price difference provided by pricing services | 5.00% |
Maximum price difference provided by pricing services | 1.0 |
Fair value, investment-related liabilities | 77.1 | 68.1
Hedge and private equity funds included in other long-term investments |  |
Investment securities |  |
Largest single fund investment | 19.2 |
Hedge funds |  |
Investment securities |  |
Number of investments | 17 |
Redemption requests | $ 13.9 |
Private equity funds |  |
Investment securities |  |
Number of investments | 36 |

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- Definition Fair value of obligations incurred from short sales. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Audit and Accounting Guide (AAG) -Number AAG-BRD -Paragraph 38 -IssueDate 2006-05-01 -Chapter 4 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Audit and Accounting Guide (AAG) -Number AAG-BRD -Paragraph 19 -IssueDate 2006-05-01 -Chapter 7 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 940 -SubTopic 320 -Section 35 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6475908&loc=d3e42429-110968 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Audit and Accounting Guide (AAG) -Number AAG-BRD -Paragraph 2 -IssueDate 2006-05-01 -Chapter 7 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Audit and Accounting Guide (AAG) -Number AAG-BRD -Paragraph 40 -IssueDate 2006-05-01 -Chapter 7 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. + Details
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- Definition Represents the maximum price difference provided by the pricing services between the market price and the actual sale price of securities, on the basis of which outliers are considered. + References No definition available. + Details
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