Segment Information - Financial Information by Geographic Segment (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Oct. 31, 2012	Oct. 31, 2011	Oct. 31, 2012	Oct. 31, 2011	Jan. 31, 2012
Segment Reporting Information [Line Items]
Stock-based compensation expense	$ (3,646)	$ (2,787)	$ (10,328)	$ (7,969)
Net sales to unaffiliated customers	6,040,556	6,593,983	17,897,617	19,375,572
Operating income	69,546	89,569	209,695	244,027
Depreciation and amortization	13,524	13,851	40,114	42,794
Capital expenditures	8,281	13,129	28,609	32,176
Identifiable assets	5,922,317	6,336,125	5,922,317	6,336,125	5,785,418
Goodwill and acquisition-related intangible assets, net	153,869	155,519	153,869	155,519
Americas [Member]
Segment Reporting Information [Line Items]
Net sales to unaffiliated customers	2,367,743	2,781,263	7,221,953	8,094,723
Operating income	33,747	52,638	114,346	148,146
Depreciation and amortization	4,079	3,798	11,900	11,567
Capital expenditures	2,420	10,085	15,111	21,340
Identifiable assets	1,870,735	2,063,622	1,870,735	2,063,622
Goodwill and acquisition-related intangible assets, net	2,966	2,966	2,966	2,966
Europe [Member]
Segment Reporting Information [Line Items]
Net sales to unaffiliated customers	3,672,813	3,812,720	10,675,664	11,280,849
Operating income	39,445	39,718	105,677	103,850
Depreciation and amortization	9,445	10,053	28,214	31,227
Capital expenditures	5,861	3,044	13,498	10,836
Identifiable assets	4,051,582	4,272,503	4,051,582	4,272,503
Goodwill and acquisition-related intangible assets, net	$ 150,903	$ 152,553	$ 150,903	$ 152,553