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Acquisitions Acquisitions (Details) - USD ($) $ in Millions | 1 Months Ended | 3 Months Ended | 6 Months Ended
--- | --- | --- | ---
Feb. 28, 2015 | Jun. 30, 2015 | Jun. 30, 2014 | Jun. 30, 2015 | Jun. 30, 2014
Business Acquisition [Line Items] |  |  |  |  |
Contingent consideration |  | $ 36.0 | $ 0.0 | $ 274.5 | $ 0.0
Convergence Pharmaceuticals |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |
Cash portion of consideration | $ 200.1 |  |  |  |
Contingent consideration | 274.5 |  |  |  |
Total purchase price | $ 474.6 |  |  |  |

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