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Fair Value Measurements (Details 3) (USD $) In Millions, unless otherwise specified | 3 Months Ended
--- | ---
Mar. 31, 2012 | Mar. 31, 2011
Changes in level 3 assets and liabilities |  |
Transfers of financial assets from level 1 to level 2 | $ 2.0 |
Other investments |  |
Changes in level 3 assets and liabilities |  |
Balance at the beginning of the period | 103.4 | 85.7
Net realized gains/losses | (0.8) | 1.1
Net unrealized gains/losses relating to instruments still held at the reporting date | 2.5 | 5.6
Purchases and issuances | 4.8 | 2.8
Settlements and reductions | (2.4) | (1.7)
Balance at the end of period | 107.5 | 93.5
Contingent payment arrangements |  |
Changes in level 3 assets and liabilities |  |
Balance at the beginning of the period | 87.1 | 77.6
Net unrealized gains/losses relating to instruments still held at the reporting date | (4.0) | 5.4
Balance at the end of period | 83.1 | 83.0
Obligations to related parties |  |
Changes in level 3 assets and liabilities |  |
Balance at the beginning of the period | 92.0 | 79.6
Net realized gains/losses | (0.3) | 0.3
Net unrealized gains/losses relating to instruments still held at the reporting date | 1.0 | 2.5
Purchases and issuances | 14.4 | 9.6
Settlements and reductions | (29.5) | (24.1)
Balance at the end of period | $ 77.6 | $ 67.9

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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 assets and liabilities measured at fair value using significant unobservable inputs (Level 3) which are required for reconciliation purposes of beginning and ending balances. + 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 The amount of the transfers of assets or liabilities 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=6925170&loc=d3e19207-110258 + Details
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