Consolidated Statement Of Income (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Oct. 31, 2014	Oct. 31, 2013	Oct. 31, 2014	Oct. 31, 2013
Income Statement [Abstract]
Net sales	$ 6,761,181	$ 6,373,564	$ 20,331,141	$ 18,848,797
Cost of products sold	6,426,196	6,047,488	19,309,456	17,884,467
Gross profit	334,985	326,076	1,021,685	964,330
Selling, general and administrative expenses	271,235	270,131	847,344	828,509
Operating expenses:	2,064	14,979	19,678	28,965
LCD settlements (Note 1)	(5,059)	(22,914)	(5,059)	(22,914)
Value added tax assessment (Note 7)	0	0	(6,229)	0
Operating expenses:	268,240	262,196	855,734	834,560
Operating income	66,745	63,880	165,951	129,770
Interest expense	6,491	6,134	20,639	19,451
Other (income) expense, net	(225)	(410)	842	(1,920)
Income before income taxes	60,479	58,156	144,470	112,239
Provision for income taxes	18,779	20,440	49,975	42,068
Net income	$ 41,700	$ 37,716	$ 94,495	$ 70,171
Net income per share:
Basic (in USD per share)	$ 1.09	$ 0.99	$ 2.47	$ 1.85
Diluted (in USD per share)	$ 1.09	$ 0.99	$ 2.46	$ 1.84
Weighted average common shares outstanding:
Basic (shares)	38,253	38,060	38,212	38,004
Diluted (shares)	38,433	38,228	38,376	38,206