Fair Value Measurements (Details 2) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Business Acquisition, Contingent Consideration [Line Items]
Additions	$ 0.0	$ 274.5
Loss (gain) on fair value remeasurement of contingent consideration	14.8	30.5	$ (38.9)
Payments	(53.2)	(14.5)
Fair Value, Measurements, Recurring
Business Acquisition, Contingent Consideration [Line Items]
Fair value, beginning of period	506.0	215.5
Fair value, end of period	$ 467.6	$ 506.0	$ 215.5