Segment Information (Financial Information By Geographic Segment) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				9 Months Ended
	Oct. 31, 2011		Oct. 31, 2010		Oct. 31, 2011		Oct. 31, 2010		Jan. 31, 2011
Segment Reporting Information [Line Items]
Net sales to unaffiliated customers	$ 6,593,983		$ 6,163,762		$ 19,375,572		$ 17,258,778
Operating income	89,569		80,972		244,027		216,216
Stock-based compensation expense	(2,787)		(2,286)		(7,969)		(7,395)
Depreciation and amortization	13,851		11,597		42,794		33,545
Capital expenditures	13,129		6,738		32,176		21,033
Identifiable assets	6,410,633		6,414,012		6,410,633		6,414,012		6,488,292
Goodwill and acquisition-related intangible assets, net	155,519	[1]	127,468	[1]	155,519	[1]	127,468	[1]
Americas [Member]
Segment Reporting Information [Line Items]
Net sales to unaffiliated customers	2,781,263		2,697,809		8,094,723		7,759,140
Operating income	52,638		46,148		148,146		135,018
Depreciation and amortization	3,798		4,098		11,567		12,293
Capital expenditures	10,085		3,359		21,340		11,461
Identifiable assets	2,129,080		2,059,194		2,129,080		2,059,194
Goodwill and acquisition-related intangible assets, net	2,966	[1]	2,966	[1]	2,966	[1]	2,966	[1]
Europe [Member]
Segment Reporting Information [Line Items]
Net sales to unaffiliated customers	3,812,720		3,465,953		11,280,849		9,499,638
Operating income	39,718		37,110		103,850		88,593
Depreciation and amortization	10,053		7,499		31,227		21,252
Capital expenditures	3,044		3,379		10,836		9,572
Identifiable assets	4,281,553		4,354,818		4,281,553		4,354,818
Goodwill and acquisition-related intangible assets, net	$ 152,553	[1]	$ 124,502	[1]	$ 152,553	[1]	$ 124,502	[1]

[1] The increase in the goodwill and acquisition-related intangible assets, net, at October 31, 2011, is primarily the result of an acquisition in Europe completed during the third quarter of fiscal 2012.