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Fair Value Measurements (Details 3) (USD $) In Millions, unless otherwise specified | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2013 | Jun. 30, 2012 | Jun. 30, 2013 | Jun. 30, 2012
Changes in level 3 assets and liabilities |  |  |  |  |  |  |  |
Transfers of financial assets from level 1 to level 2 |  |  | $ 2.0 |  |  |  | $ 2.0 |
Other investments [Member] |  |  |  |  |  |  |  |
Changes in level 3 assets and liabilities |  |  |  |  |  |  |  |
Balance at the beginning of the period | 121.9 |  | 107.5 |  | 118.9 |  | 103.4 |
Net realized gains/losses | (0.9) | [1] | (0.9) | [1] | (1.4) | [1] | (1.7) | [1]
Net unrealized gains/losses relating to instruments still held at the reporting date | 3.9 | [1] | 3.6 | [1] | 6.4 | [1] | 6.1 | [1]
Purchases and issuances | 2.8 |  | 5.2 |  | 7.7 |  | 10.0 |
Settlements and reductions | (3.3) |  | (2.4) |  | (7.2) |  | (4.8) |
Net transfers in and/or out of Level 3 | 0 |  | 0 |  | 0 |  | 0 |
Balance at the end of period | 124.4 |  | 113.0 |  | 124.4 |  | 113.0 |
Contingent payment arrangements [Member] |  |  |  |  |  |  |  |
Changes in level 3 assets and liabilities |  |  |  |  |  |  |  |
Balance at the beginning of the period | 40.5 |  | 83.1 |  | 31.0 |  | 87.1 |
Net realized gains/losses | 0 |  | 0 |  | 0 |  | 0 |
Net unrealized gains/losses relating to instruments still held at the reporting date | 3.8 | [2] | (45.4) | [2] | 13.3 | [2] | (49.4) | [2]
Purchases and issuances | 0 |  | 24.8 |  | 0 |  | 24.8 |
Settlements and reductions | 0 |  | 0 |  | 0 |  | 0 |
Net transfers in and/or out of Level 3 | 0 |  | 0 |  | 0 |  | 0 |
Balance at the end of period | 44.3 |  | 62.5 |  | 44.3 |  | 62.5 |
Obligations to related parties [Member] |  |  |  |  |  |  |  |
Changes in level 3 assets and liabilities |  |  |  |  |  |  |  |
Balance at the beginning of the period | 90.7 |  | 77.6 |  | 77.8 |  | 92.0 |
Net realized gains/losses | 0.6 | [3] | 0.7 | [3] | 2.0 | [3] | 0.5 | [3]
Net unrealized gains/losses relating to instruments still held at the reporting date | 0.6 | [3] | (0.2) | [3] | 0.2 | [3] | 0.8 | [3]
Purchases and issuances | 16.9 |  | 6.0 |  | 32.0 |  | 20.3 |
Settlements and reductions | (12.2) |  | (4.6) |  | (15.4) |  | (34.1) |
Net transfers in and/or out of Level 3 | 0 |  | 0 |  | 0 |  | 0 |
Balance at the end of period | $ 96.6 |  | $ 79.5 |  | $ 96.6 |  | $ 79.5 |
[1] | Gains and losses on Other investments are recorded in Investment and other income.
[2] | Accretion and changes to payment estimates under the Company's contingent payment arrangements are recorded in Imputed interest and contingent payment arrangements and foreign currency translation adjustments related to such arrangements are recorded as Other comprehensive income.
[3] | Gains and losses associated with agreements to repurchase Affiliate equity are recorded in Imputed interest and contingent payment arrangements. Gains and losses related to liabilities offsetting certain investments are recorded in Investment and other income.

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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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