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Fair Value Measurements (Details 3) (USD $) In Millions, unless otherwise specified | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2012 | Sep. 30, 2011 | Sep. 30, 2012 | Sep. 30, 2011
Changes in level 3 assets and liabilities |  |  |  |
Transfers of financial assets from level 1 to level 2 | $ 2.0 |  | $ 2.0 |
Other investments |  |  |  |
Changes in level 3 assets and liabilities |  |  |  |
Balance at the beginning of the period | 113.0 | 102.0 | 103.4 | 85.8
Net realized gains/losses | (0.1) | (0.3) | (1.7) | 0.7
Net unrealized gains/losses relating to instruments still held at the reporting date | 1.6 | 3.5 | 7.7 | 14.0
Purchases and issuances | 3.5 | 4.2 | 13.4 | 12.8
Settlements and reductions | (1.3) | (2.1) | (6.1) | (6.0)
Balance at the end of period | 116.7 | 107.3 | 116.7 | 107.3
Contingent payment arrangements |  |  |  |
Changes in level 3 assets and liabilities |  |  |  |
Balance at the beginning of the period | 62.5 | 85.3 | 87.1 | 77.6
Net unrealized gains/losses relating to instruments still held at the reporting date | 3.5 | 2.0 | (45.9) | 11.4
Purchases and issuances |  |  | 24.8 |
Settlements and reductions |  |  |  | (1.7)
Balance at the end of period | 66.0 | 87.3 | 66.0 | 87.3
Obligations to related parties |  |  |  |
Changes in level 3 assets and liabilities |  |  |  |
Balance at the beginning of the period | 79.5 | 71.2 | 92.0 | 79.6
Net realized gains/losses | 0.5 | 0.8 | 0.9 | 1.4
Net unrealized gains/losses relating to instruments still held at the reporting date | 0.2 | (0.4) | 0.9 | 3.2
Purchases and issuances | 1.7 | 8.5 | 22.1 | 21.5
Settlements and reductions | (6.1) | (8.5) | (40.1) | (34.1)
Balance at the end of period | $ 75.8 | $ 71.6 | $ 75.8 | $ 71.6

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- Definition Represents total realized gains or losses for the period, arising from assets and liabilities measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in earnings or other comprehensive income. + References No definition available. + Details
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- Definition Represents purchases, sales, issuances, and settlements (net) which have taken place during the period in relation to assets and liabilities measured at fair value on a recurring basis using unobservable inputs (Level 3). + References No definition available. + Details
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- Definition Represents settlements and reductions which have taken place during the period in relation to assets and liabilities measured at fair value on a recurring basis using unobservable inputs (Level 3). + References No definition available. + Details
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- Definition Represents total unrealized gains or losses for the period, arising from assets and liabilities measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in earnings or other comprehensive income. + References No definition available. + Details
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- Definition Amount of transfers of assets measured on a recurring basis out of Level 1 of the fair value hierarchy into Level 2. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (bb) -URI http://asc.fasb.org/extlink&oid=7578670&loc=d3e19207-110258 + Details
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