Consolidated Statement Of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 31, 2016	Jul. 31, 2015	Jul. 31, 2016	Jul. 31, 2015
Income Statement [Abstract]
Net sales	$ 6,353,739	$ 6,580,393	$ 12,317,101	$ 12,467,622
Cost of products sold	6,037,289	6,255,114	11,702,040	11,850,454
Gross profit	316,450	325,279	615,061	617,168
Selling, general and administrative expenses	243,763	250,134	490,259	498,596
LCD settlements and other, net	(1,717)	(21,527)	(2,160)	(60,038)
Value added tax assessments	1,049	(9,563)	1,049	(9,563)
Operating expenses	243,095	219,044	489,148	428,995
Operating income	73,355	106,235	125,913	188,173
Interest expense	6,288	(3,320)	11,889	2,402
Other (income) expense, net	(1,230)	51	(2,264)	212
Income before income taxes	68,297	109,504	116,288	185,559
Provision for income taxes	21,903	33,092	36,521	57,870
Net income	$ 46,394	$ 76,412	$ 79,767	$ 127,689
Earnings per share:
Basic	$ 1.32	$ 2.09	$ 2.27	$ 3.48
Diluted	$ 1.31	$ 2.09	$ 2.26	$ 3.47
Weighted average common shares outstanding:
Basic	35,207	36,506	35,167	36,661
Diluted	35,378	36,615	35,373	36,829