Business and Summary of Significant Accounting Policies - Computer Equipment, Software, Furniture and Leasehold Improvements, Net (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Jan. 31, 2014	Jan. 31, 2013	Jan. 31, 2012
Property, Plant and Equipment [Abstract]
Depreciation	$ 47.2	$ 45.6	$ 43.7
Computer hardware, at cost	163.0	152.3
Computer software, at cost	80.9	95.1
Leasehold improvements, land and buildings, at cost	163.7	152.4
Furniture and equipment, at cost	51.7	46.0
Computer software, hardware, leasehold improvements, furniture and equipment, at cost	459.3	445.8
Less: Accumulated depreciation	(329.0)	(330.9)
Computer software, hardware, leasehold improvements, furniture and equipment, net	130.3	114.9
Write off of fully depreciated assets	$ 48.2