Fair Value Measurement (Assets and Liabilities Measure at Fair Value on Recurring Basis using Level 3 Inputs) (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	$ 13.8	$ 15.9
Change in fair value included in earnings	3.6	9.8
Other	(1.7)	(10.8)
Balance at end of period	15.7	14.9
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	475.9	629.9
Additions	557.0	92.8
Change in fair value included in earnings	(34.8)	(196.5)
Other	(1.4)	(5.6)
Balance at end of period	$ 996.7	$ 520.6