Acquisitions (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Jan. 31, 2016	Jun. 01, 2015	Nov. 01, 2013
TDMobility
Business Acquisition [Line Items]
Identifiable intangible assets			$ 4.2
Goodwill, Gross			2.5
Acquisition purchase price	$ 2.1
Tangible assets (includes property and equipment, deferred tax assets and other assets)			4.0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities			$ 6.7
STG
Business Acquisition [Line Items]
Identifiable intangible assets		$ 14.5
Goodwill, Gross		14.1
Acquisition purchase price	$ 27.8
Tangible assets (includes property and equipment, deferred tax assets and other assets)		0.3
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities		$ 1.1
Minimum | TDMobility
Business Acquisition [Line Items]
Acquired finite lived intangible assets, useful life (in years)	5 years
Maximum | TDMobility
Business Acquisition [Line Items]
Acquired finite lived intangible assets, useful life (in years)	10 years
Maximum | STG
Business Acquisition [Line Items]
Acquired finite lived intangible assets, useful life (in years)	10 years