Segment Information (Revenues And Long-Lived Assets By Geographic Area) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	$ 3,453.2	$ 3,187.0	$ 10,025.1	$ 9,183.5
Long-lived Assets	1,323.3		1,323.3		$ 1,271.4
North America [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	2,709.4	2,510.6	7,830.8	7,226.5
Long-lived Assets	284.1		284.1		242.4
Europe [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	537.7	509.1	1,610.3	1,487.3
Long-lived Assets	36.1		36.1		32.2
UNITED KINGDOM
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	293.0	299.9	902.5	882.6
Europe, excluding United Kingdom [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	244.7	209.2	707.8	604.7
Other Regions [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	206.1	$ 167.3	584.0	$ 469.7
Long-lived Assets	$ 1,003.1		$ 1,003.1		$ 996.8