Property And Equipment (Summary Of Property And Equipment) (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 4,058.4	$ 3,764.8
Accumulated depreciation and amortization	(2,038.6)	(1,820.5)
Property and equipment, net	2,019.8	1,944.3
Land and Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	21.5	25.8
Buildings and Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	216.6	279.9
Data Processing Equipment, Furniture and Other Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	1,046.1	940.3
Computer Software, Purchased and Internally Developed [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	2,344.9	2,162.4
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 429.3	$ 356.4