Segment Information (Details) - USD ($) $ in Thousands		3 Months Ended				6 Months Ended
		Jul. 31, 2015		Jul. 31, 2014		Jul. 31, 2015		Jul. 31, 2014		Jan. 31, 2015
Segment Reporting Information
Revenue, net		$ 6,580,393		$ 6,841,809		$ 12,467,622		$ 13,569,960
Operating income (loss)		106,235		67,710		188,173		99,206
Share-based compensation expense		(3,960)		(3,869)		(7,778)		(5,842)
Depreciation and amortization		13,992		17,713		28,171		35,929
Capital expenditures		7,752		7,241		14,996		11,468
Assets		6,145,569				6,145,569				$ 6,136,725
Long-lived assets		63,070				63,070				63,104
Goodwill & acquisition-related intangible assets, net		334,850				334,850				317,968
Gain (Loss) Related to Litigation Settlement		(21,527)		0		(60,038)		0
BusinessExitCosts1		154		0		517		0
Operating expenses, restatement and remediation related expenses		164		5,378		782		17,614
Loss Contingency Accrual, Period Increase (Decrease)		(9,563)		(6,229)		(9,563)		(6,229)
Americas
Segment Reporting Information
Revenue, net	[1]	2,745,429		2,722,191		5,084,689		5,198,462
Operating income (loss)		60,752	[2]	38,854		123,111	[3]	65,137	[3]
Depreciation and amortization		$ 4,472		$ 4,188		$ 8,513		$ 8,306
Sales to unaffiliated customers, as percentage of total sales		91.00%		87.00%		89.00%		85.00%
Capital expenditures		$ 4,222		$ 3,370		$ 8,086		$ 4,852
Assets		2,185,420				2,185,420				1,949,414
Long-lived assets	[1]	25,910				25,910				24,121
Goodwill & acquisition-related intangible assets, net		$ 36,811				$ 36,811				$ 8,810
Long-lived assets, as percentage of total assets		93.00%				93.00%				92.00%
Gain (Loss) Related to Litigation Settlement		$ (21,527)				$ (60,038)
Operating expenses, restatement and remediation related expenses		146		190		184		3,060
Europe
Segment Reporting Information
Revenue, net		3,834,964		4,119,618		7,382,933		8,371,498
Operating income (loss)		49,443	[4]	32,725	[4]	72,840	[5]	39,911	[5]
Depreciation and amortization		9,520		13,525		19,658		27,623
Capital expenditures		3,530		3,871		6,910		6,616
Assets		3,960,149				3,960,149				$ 4,187,311
Long-lived assets		37,160				37,160				38,983
Goodwill & acquisition-related intangible assets, net		298,039				298,039				$ 309,158
Operating expenses, restatement and remediation related expenses				5,188		$ 598		14,554
Value added tax assessment [Member] | SPAIN
Segment Reporting Information
Loss Contingency Accrual, Period Increase (Decrease)		$ (16,400)		$ (6,229)				$ (6,229)

[1] Net sales to unaffiliated customers in the United States represented 91% and 87%, respectively, of the total Americas' net sales to unaffiliated customers for the three months ended July 31, 2015 and 2014. Net sales to unaffiliated customers in the United States represented 89% and 85%, respectively, of the total Americas' net sales to unaffiliated customers for the six months ended July 31, 2015 and 2014. Total long-lived assets in the United States represented 93% and 92% of the Americas' total long-lived assets at July 31, 2015 and January 31, 2015, respectively.

[2] Operating income in the Americas for the three months ended July 31, 2015 includes a gain related to LCD settlements, net of $21.5 million and restatement and remediation related expenses of $0.1 million. Operating income in the Americas for the six months ended July 31, 2015 includes a gain related to LCD settlements, net of $60.0 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 and six months ended July 31, 2014 includes restatement and remediation related expenses of $0.2 million and $3.1 million, respectively (see further discussion in Note 1 – Business and Summary of Significant Accounting Policies).

[4] Operating income in Europe for the three and six months ended July 31, 2015 includes a decrease in the accrual for assessments and penalties for various VAT matters in two European subsidiaries (see further discussion in Note 9 – Commitments & Contingencies). Operating income in Europe for the six months ended July 31, 2015 includes restatement and remediation expenses of $0.6 million (see further discussion in Note 1 – Business and Summary of Significant Accounting Policies).

[5] Operating income in Europe for the three and six months ended July 31, 2014 includes restatement and remediation related expenses of $5.2 million and $14.6 million, respectively (see further discussion in Note 1 – Business and Summary of Significant Accounting Policies) and a decrease in the accrual for VAT matters in the Company's Spanish subsidiary of $6.2 million (see further discussion in Note 9 – Commitments & Contingencies).