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Investment Securities (Fair Value of Hedge Funds Subject to Restrictions on Redemption Frequency) (Details) (USD $) In Millions, unless otherwise specified | Mar. 31, 2013 | Dec. 31, 2012 | Mar. 31, 2012 | Dec. 31, 2011
--- | --- | --- | --- | ---
Hedge funds |  |  |  |  |  |
Investment securities |  |  |  |  |  |
Other long-term investments | $ 117.7 |  |  |  |  |
Private equity funds |  |  |  |  |  |
Investment securities |  |  |  |  |  |
Other long-term investments | 122.1 |  |  |  |  |
Hedge and private equity funds included in other long-term investments |  |  |  |  |  |
Investment securities |  |  |  |  |  |
Other long-term investments | 239.8 | [1] | 239.8 | [1] |  |
Carrying value excluded associated with hedge funds and private equity funds | 134.9 | [1] | 133.4 | [1] |  |
Hedge funds | Hedge Funds, Equity |  |  |  |  |  |
Investment securities |  |  |  |  |  |
Other long-term investments | 60.0 |  | 60.3 |  |  |
Carrying value excluded associated with hedge funds and private equity funds | 0 |  | 0 |  |  |
Hedge funds | Hedge Funds Credit and Distressed |  |  |  |  |  |
Investment securities |  |  |  |  |  |
Other long-term investments | 24.5 |  | 22.7 |  |  |
Carrying value excluded associated with hedge funds and private equity funds | 0 |  | 0 |  |  |
Hedge funds | Hedge Funds Diversified Strategies |  |  |  |  |  |
Investment securities |  |  |  |  |  |
Other long-term investments | 1.7 |  | 1.7 |  |  |
Carrying value excluded associated with hedge funds and private equity funds | 0 |  | 0 |  |  |
Hedge funds | Hedge Funds Equity R E I T |  |  |  |  |  |
Investment securities |  |  |  |  |  |
Other long-term investments | 16.7 |  | 16.0 |  |  |
Carrying value excluded associated with hedge funds and private equity funds | 0 |  | 0 |  |  |
Hedge funds | Hedge Funds Equity Activist |  |  |  |  |  |
Investment securities |  |  |  |  |  |
Other long-term investments | 14.5 |  | 13.6 |  |  |
Carrying value excluded associated with hedge funds and private equity funds | 0 |  | 0 |  |  |
Hedge funds | Hedge Funds Bank Loan |  |  |  |  |  |
Investment securities |  |  |  |  |  |
Other long-term investments | 0.3 |  | 0.3 |  |  |
Carrying value excluded associated with hedge funds and private equity funds | 0 |  | 0 |  |  |
Hedge funds | Hedge funds |  |  |  |  |  |
Investment securities |  |  |  |  |  |
Other long-term investments | 117.7 |  | 114.6 |  |  |
Carrying value excluded associated with hedge funds and private equity funds | 0 |  | 0 |  |  |
Private equity funds | Private Equity Multi Sector |  |  |  |  |  |
Investment securities |  |  |  |  |  |
Other long-term investments | 25.9 |  | 23.3 |  |  |
Carrying value excluded associated with hedge funds and private equity funds | 8.9 |  | 5.4 |  |  |
Private equity funds | Private Equity Energy Infrastructure and Services |  |  |  |  |  |
Investment securities |  |  |  |  |  |
Other long-term investments | 35.0 |  | 36.3 |  |  |
Carrying value excluded associated with hedge funds and private equity funds | 14.8 |  | 15.6 |  |  |
Private equity funds | Private Equity Distressed Residential Real Estate |  |  |  |  |  |
Investment securities |  |  |  |  |  |
Other long-term investments | 14.6 |  | 15.8 |  |  |
Carrying value excluded associated with hedge funds and private equity funds | 0 |  | 0 |  |  |
Private equity funds | Real Estate Funds |  |  |  |  |  |
Investment securities |  |  |  |  |  |
Other long-term investments | 10.9 |  | 11.6 |  |  |
Carrying value excluded associated with hedge funds and private equity funds | 3.3 |  | 3.3 |  |  |
Private equity funds | Private Equity Secondaries |  |  |  |  |  |
Investment securities |  |  |  |  |  |
Other long-term investments | 10.6 |  | 10.5 |  |  |
Carrying value excluded associated with hedge funds and private equity funds | 3.1 |  | 3.1 |  |  |
Private equity funds | Private Equity Funds Multi Sector Europe |  |  |  |  |  |
Investment securities |  |  |  |  |  |
Other long-term investments | 4.2 |  | 5.1 |  |  |
Carrying value excluded associated with hedge funds and private equity funds | 5.0 |  | 5.0 |  |  |
Private equity funds | Private Equity Funds Manufacturing and Industrial |  |  |  |  |  |
Investment securities |  |  |  |  |  |
Other long-term investments | 9.0 |  | 9.9 |  |  |
Carrying value excluded associated with hedge funds and private equity funds | 28.7 |  | 29.1 |  |  |
Private equity funds | Private Equity Healthcare |  |  |  |  |  |
Investment securities |  |  |  |  |  |
Other long-term investments | 4.2 |  | 4.3 |  |  |
Carrying value excluded associated with hedge funds and private equity funds | 5.0 |  | 5.4 |  |  |
Private equity funds | Private Equity Funds Multi Sector Asia |  |  |  |  |  |
Investment securities |  |  |  |  |  |
Other long-term investments | 0 |  | 0.4 |  |  |
Carrying value excluded associated with hedge funds and private equity funds | 2.7 |  | 2.7 |  |  |
Private equity funds | Private Equity Insurance |  |  |  |  |  |
Investment securities |  |  |  |  |  |
Other long-term investments | 2.5 |  | 3.0 |  |  |
Carrying value excluded associated with hedge funds and private equity funds | 41.3 |  | 41.3 |  |  |
Private equity funds | Aerospace Defense Government |  |  |  |  |  |
Investment securities |  |  |  |  |  |
Other long-term investments | 3.0 |  | 2.8 |  |  |
Carrying value excluded associated with hedge funds and private equity funds | 21.8 |  | 22.2 |  |  |
Private equity funds | Venture Capital Funds |  |  |  |  |  |
Investment securities |  |  |  |  |  |
Other long-term investments | 2.2 |  | 2.2 |  |  |
Carrying value excluded associated with hedge funds and private equity funds | 0.3 |  | 0.3 |  |  |
Private equity funds | Private equity funds |  |  |  |  |  |
Investment securities |  |  |  |  |  |
Other long-term investments | 122.1 |  | 125.2 |  |  |
Carrying value excluded associated with hedge funds and private equity funds | 134.9 |  | 133.4 |  |  |
Level 3 Inputs | Fair value measured on a recurring basis | Other long-term investments |  |  |  |  |  |
Investment securities |  |  |  |  |  |
Carrying value of investment accounted for using the equity method | $ 34.9 |  | $ 35.0 |  | $ 33.0 | $ 33.2
[1] | Excludes carrying value of $35.0 and $34.9 at January 1, 2013 and March 31, 2013 associated with hedge funds and private equity funds accounted for using the equity method.

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- Definition This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents investments accounted for under the equity method of accounting as of the balance sheet date. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 18 -Paragraph 6 -Subparagraph b -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 FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 25 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6903542&loc=d3e32014-111567 + Details
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- Definition This element represents the total fair market value of investments in certain entities that calculate net asset value per share (including by unit, membership interest, or other equity (ownership interest) unit measure) (alternative investments). This element is intended to be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements, but may also be used in both the balance sheet and disclosure in the same submission. This item represents alternative investments as of the balance sheet date which may include investments in certain hedge funds, venture capital funds, private equity funds, real estate partnerships or funds, and any other investment in which investee management calculates net asset value per share as the primary metric for investment value. + References No definition available. + Details
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