Segment Information (Financial Information By Geographic Segment) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Jan. 31, 2016	Oct. 31, 2015	Jul. 31, 2015	Apr. 30, 2015	Jan. 31, 2015	Oct. 31, 2014	Jul. 31, 2014	Apr. 30, 2014	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014
Segment Reporting Information [Line Items]
Net sales	$ 7,483,621	$ 6,428,540	$ 6,580,393	$ 5,887,229	$ 7,339,491	$ 6,761,181	$ 6,841,809	$ 6,728,151	$ 26,379,783	$ 27,670,632	$ 26,821,904
Stock-based compensation expense									(14,890)	(13,668)	(8,858)
Operating income	145,202	68,053	$ 106,235	$ 81,938	101,684	66,745	67,710	31,496	401,428	267,635	227,513
Depreciation and amortization:									57,253	68,746	72,979
Capital expenditures									33,972	28,175	28,869
Identifiable assets	6,358,288				6,136,725				6,358,288	6,136,725
Long-lived assets	66,028				63,104				66,028	63,104
Goodwill and acquisition-related intangible assets, net	310,016				317,968				310,016	317,968
Gain (Loss) Related to Litigation Settlement		$ 5,100			35,400	3,000	21,500	38,500	98,433	5,059	35,511
Operating Expenses, Restatement and Remediation Related					2,300	$ 2,100	5,400	$ 12,200	829	22,043	53,791
Operating expenses, value added tax assessments									(8,796)	(6,229)	0
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount									(11,300)	(29,800)
Europe
Segment Reporting Information [Line Items]
Operating expenses, value added tax assessments							$ (6,200)
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount	(19,200)									(19,200)	(45,300)
Americas
Segment Reporting Information [Line Items]
Net sales									10,356,716	10,406,209	10,188,618
Operating income									235,577	145,107	156,143
Depreciation and amortization:									18,243	16,653	16,763
Capital expenditures									18,139	13,798	$ 9,530
Identifiable assets	2,078,443				1,949,414				2,078,443	1,949,414
Long-lived assets	29,402				24,121				29,402	24,121
Goodwill and acquisition-related intangible assets, net	35,615				8,810				35,615	8,810
Gain (Loss) Related to Litigation Settlement									5,100	35,500
Operating Expenses, Restatement and Remediation Related									$ 4,000	$ 13,200
Americas | Geographic Concentration Risk | United States | Sales Revenue, Segment
Segment Reporting Information [Line Items]
Concentration risk, percentage									90.00%	85.00%	86.00%
Americas | Geographic Concentration Risk | United States | Assets, Total
Segment Reporting Information [Line Items]
Concentration risk, percentage									95.00%	92.00%
Europe
Segment Reporting Information [Line Items]
Net sales									$ 16,023,067	$ 17,264,423	$ 16,633,286
Operating income									180,741	136,196	80,228
Depreciation and amortization:									39,010	52,093	56,216
Capital expenditures									15,833	14,377	$ 19,339
Identifiable assets	4,279,845				4,187,311				4,279,845	4,187,311
Long-lived assets	36,626				38,983				36,626	38,983
Goodwill and acquisition-related intangible assets, net	$ 274,401				$ 309,158				274,401	309,158
Operating Expenses, Restatement and Remediation Related									18,100	40,600
Spain
Segment Reporting Information [Line Items]
Operating expenses, value added tax assessments										$ (6,200)
Litigation Charge | Spain
Segment Reporting Information [Line Items]
Operating expenses, value added tax assessments									$ (8,800)