Acquisitions (Purchase Price Allocation)(Details) (USD $)	Jan. 31, 2014	Jan. 31, 2013	Nov. 02, 2012 SDG	Nov. 02, 2013 TDMobility [Member]
Business Acquisition [Line Items]
Business Acquisition, Purchase Price Allocation, Liabilities Assumed				$ 6,100,000
Cash			65,000,000
Accounts receivable			260,800,000
Inventories			126,100,000
Tangible assets (includes property and equipment, deferred tax assets and other assets)			6,200,000	4,000,000
Goodwill	230,472,000	225,045,000	122,600,000
Identifiable intangible assets			134,300,000	4,200,000
Accounts payable			(265,200,000)
Liabilities (includes accrued expenses, deferred tax liability and other liabilities)			(91,800,000)
Purchase price of acquired entity			$ 358,000,000