Fair Value Measurement (Assets and Liabilities Measure at Fair Value on Recurring Basis using Level 3 Inputs) (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at January 1,	$ 15.6	$ 13.8
Change in fair value included in earnings	(2.3)	2.1
Other	(3.5)	1.6
Balance as of June 30,	9.8	17.5
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at January 1,	1,058.0	475.9
Acquisitions	(4.0)	562.5
Change in fair value included in earnings	147.7	(45.0)
Other	(11.4)	0.4
Balance as of June 30,	$ 1,190.3	$ 993.8