Integration and Acquisition Costs (Summary of Employee Termination Related Reserve and Other) (Details) $ in Millions	6 Months Ended
	Jun. 30, 2018 USD ($)
Restructuring Reserve [Roll Forward]
As of January 1,	$ 129.5
Amount charged to integration costs	10.5
Paid/utilized	(72.9)
As of June 30,	67.1
Severance and employee benefits
Restructuring Reserve [Roll Forward]
As of January 1,	72.9
Amount charged to integration costs	8.4
Paid/utilized	(61.8)
As of June 30,	19.5
Lease terminations
Restructuring Reserve [Roll Forward]
As of January 1,	56.6
Amount charged to integration costs	2.1
Paid/utilized	(11.1)
As of June 30,	$ 47.6