Segment Information (Details) - USD ($) $ in Thousands		3 Months Ended				9 Months Ended
		Oct. 31, 2015		Oct. 31, 2014		Oct. 31, 2015		Oct. 31, 2014		Jan. 31, 2015
Segment Reporting Information
Net sales to unaffiliated customers:		$ 6,428,540		$ 6,761,181		$ 18,896,162		$ 20,331,141
Operating income:		68,053		66,745		256,226		165,951
Stock-based compensation expense		(3,621)		(3,856)		(11,399)		(9,698)
Depreciation and amortization:		14,347		16,762		42,518		52,691
Capital expenditures:		8,181		7,752		23,177		19,220
Identifiable assets:		6,365,067				6,365,067				$ 6,136,725
Long-lived assets:		63,964				63,964				63,104
Goodwill & acquisition-related intangible assets, net:		328,126				328,126				317,968
Gain (Loss) Related to Litigation Settlement		3,049		5,059		63,087		5,059
Operating expenses, restatement and remediation related expenses		47		2,064		829		19,678
Loss Contingency Accrual, Period Increase (Decrease)		0		0		(9,563)		(6,229)
Americas
Segment Reporting Information
Net sales to unaffiliated customers:	[1]	2,572,751		2,644,085		7,657,440		7,842,547
Operating income:		38,857	[2]	42,194	[3]	161,968	[2]	107,331	[3]
Depreciation and amortization:		$ 4,884		$ 4,224		$ 13,397		$ 12,530
Sales to unaffiliated customers, as percentage of total sales		91.00%		86.00%		90.00%		86.00%
Capital expenditures:		$ 4,046		$ 3,391		$ 12,132		$ 8,243
Identifiable assets:		2,242,988				2,242,988				1,949,414
Long-lived assets:	[1]	26,947				26,947				24,121
Goodwill & acquisition-related intangible assets, net:		$ 36,228				$ 36,228				$ 8,810
Long-lived assets, as percentage of total assets		94.00%				94.00%				92.00%
Gain (Loss) Related to Litigation Settlement		$ 3,049		5,059		$ 63,087		5,059
Operating expenses, restatement and remediation related expenses				900		218		3,900
Europe
Segment Reporting Information
Net sales to unaffiliated customers:		3,855,789		4,117,096		11,238,722		12,488,594
Operating income:		32,817		28,407	[4]	105,657	[5]	68,318	[4]
Depreciation and amortization:		9,463		12,538		29,121		40,161
Capital expenditures:		4,135		4,361		11,045		10,977
Identifiable assets:		4,122,079				4,122,079				$ 4,187,311
Long-lived assets:		37,017				37,017				38,983
Goodwill & acquisition-related intangible assets, net:		291,898				291,898				309,158
Operating expenses, restatement and remediation related expenses				$ 1,200		611		15,700
Value added tax assessment [Member] | Europe
Segment Reporting Information
Loss Contingency Accrual, Period Increase (Decrease)						(9,600)
Value added tax assessment [Member] | Spain
Segment Reporting Information
Loss Contingency Accrual, Period Increase (Decrease)						(16,400)		$ (6,229)
Loss Contingency Accrual		$ 4,700				$ 4,700				$ 43,700

[1] Net sales to unaffiliated customers in the United States represented 91% and 86%, respectively, of the total Americas' net sales to unaffiliated customers for the three months ended October 31, 2015 and 2014. Net sales to unaffiliated customers in the United States represented 90% and 86%, respectively, of the total Americas' net sales to unaffiliated customers for the nine months ended October 31, 2015 and 2014. Total long-lived assets in the United States represented 94% and 92% of the Americas' total long-lived assets at October 31, 2015 and January 31, 2015, respectively.

[2] Operating income in the Americas for the three months ended October 31, 2015 includes a gain related to LCD settlements, net, of $3.0 million. Operating income in the Americas for the nine months ended October 31, 2015 includes a gain related to LCD settlements, net, of $63.1 million and restatement and remediation related expenses of $0.2 million (see further discussion in Note 1 – Business and Summary of Significant Accounting Policies).

[3] Operating income in the Americas for the three months ended October 31, 2014 includes a gain related to LCD settlements, net, of $5.1 million and restatement and remediation related expenses of $0.9 million. Operating income in the Americas for the nine months ended October 31, 2014 includes the gain related to LCD settlements, net, of $5.1 million and restatement and remediation related expenses of $3.9 million (see further discussion in Note 1 – Business and Summary of Significant Accounting Policies).

[4] Operating income in Europe for the three and nine months ended October 31, 2014 includes restatement and remediation related expenses of $1.2 million and $15.7 million, respectively (see further discussion in Note 1 – Business and Summary of Significant Accounting Policies). Operating income in Europe for the nine months ended October 31, 2014 includes a decrease in the accrual for VAT matters in the Company's Spanish subsidiary of $6.2 million (see further discussion in Note 10 – Commitments & Contingencies).

[5] Operating income in Europe for the nine months ended October 31, 2015 includes a net decrease in the accrual for assessments and penalties for various VAT matters in two European subsidiaries of $9.6 million (see further discussion in Note 10 – Commitments & Contingencies) and restatement and remediation expenses of $0.6 million (see further discussion in Note 1 – Business and Summary of Significant Accounting Policies).