Acquisitions (Purchase Price Allocation)(Details) (USD $) In Thousands, unless otherwise specified	Jan. 31, 2013	Jan. 31, 2012	Nov. 02, 2012 SDG
Business Acquisition [Line Items]
Cash			$ 65,000
Accounts receivable			260,800
Inventories			126,100
Tangible assets (includes property and equipment, deferred tax assets and other assets)			6,200
Goodwill	225,045	96,793	122,600
Identifiable intangible assets			134,300
Accounts payable			(265,200)
Liabilities (includes accrued expenses, deferred tax liability and other liabilities)			(91,800)
Purchase price of acquired entity			$ 358,000