Integration and Acquisition Costs (Summary of Employee Termination Related Reserve and Other) (Details) $ in Millions	9 Months Ended
	Sep. 30, 2018 USD ($)
Restructuring Reserve [Roll Forward]
As of January 1,	$ 129.5
Amount charged to integration costs	11.5
Paid/utilized	(60.9)
As of September 30,	80.1
Severance and employee benefits
Restructuring Reserve [Roll Forward]
As of January 1,	72.9
Amount charged to integration costs	9.2
Paid/utilized	(41.0)
As of September 30,	41.1
Lease terminations
Restructuring Reserve [Roll Forward]
As of January 1,	56.6
Amount charged to integration costs	2.3
Paid/utilized	(19.9)
As of September 30,	$ 39.0