Acquisitions Summary of Fair Value of Assets Acquired and Liabilities Assumed by Major Class (Details) (USD $) In Millions, unless otherwise specified	Nov. 21, 2013	Oct. 31, 2013	Jan. 31, 2013
Business Acquisition [Line Items]
Goodwill acquired		$ 922.3	$ 871.5
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net	87.0
Other Acquistions [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities Noncurrent		0.7
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Assets		1.5
Goodwill acquired		50.7
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net		68.3
Other Acquistions [Member] | Developed Technology Rights [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles		11.3
Other Acquistions [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles		2.6
Other Acquistions [Member] | Trade Names [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles		$ 1.5