Basis of Presentation Reclassification (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Oct. 31, 2014	Oct. 31, 2013	Oct. 31, 2014	Oct. 31, 2013
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
(Decrease) to general and administrative	$ 78.9	$ 55.8	$ 212.9	$ 158.8
Increase to amortization of purchased intangibles	9.5	7.4	30.5	27.5
Reclassification of Amortization Of Intangible Assets
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
(Decrease) to general and administrative		(7.4)	(10.9)	(27.5)
Increase to amortization of purchased intangibles		$ 7.4	$ 10.9	$ 27.5