Buildings and Equipment (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Property, Plant and Equipment [Line Items]
Original Cost	$ 1,061.3
Accumulated Depreciation	617.0
Net Book Value	444.3	458.8
Land Improvements
Property, Plant and Equipment [Line Items]
Original Cost	26.5
Accumulated Depreciation	0.7
Net Book Value	25.8
Buildings
Property, Plant and Equipment [Line Items]
Original Cost	232.8
Accumulated Depreciation	117.5
Net Book Value	115.3
Equipment
Property, Plant and Equipment [Line Items]
Original Cost	392.2
Accumulated Depreciation	234.7
Net Book Value	157.5
Leasehold Improvements
Property, Plant and Equipment [Line Items]
Original Cost	327.3
Accumulated Depreciation	212.1
Net Book Value	115.2
Buildings Leased under Capital Leases
Property, Plant and Equipment [Line Items]
Original Cost	82.5
Accumulated Depreciation	52.0
Net Book Value	$ 30.5