Consolidated Statement Of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 31, 2017	Oct. 31, 2016	Oct. 31, 2017	Oct. 31, 2016
Income Statement [Abstract]
Net sales	$ 9,135,728	$ 6,490,265	$ 25,682,482	$ 18,807,366
Cost of products sold	8,609,647	6,174,426	24,183,722	17,876,466
Gross profit	526,081	315,839	1,498,760	930,900
Selling, general and administrative expenses	416,766	239,952	1,179,996	730,211
Acquisition, integration and restructuring expenses	29,748	13,015	101,931	14,997
LCD settlements and other, net	0	0	(41,343)	(4,142)
Value added tax assessments	0	0	0	1,049
Operating expenses	446,514	252,967	1,240,584	742,115
Operating income	79,567	62,872	258,176	188,785
Interest expense	25,925	9,475	85,205	21,364
Other (income) expense, net	(1,243)	1,747	(1,374)	(517)
Income before income taxes	54,885	51,650	174,345	167,938
Provision for income taxes	17,617	15,144	58,964	51,665
Net income	$ 37,268	$ 36,506	$ 115,381	$ 116,273
Earnings per share:
Basic	$ 0.98	$ 1.04	$ 3.05	$ 3.30
Diluted	$ 0.97	$ 1.03	$ 3.03	$ 3.29
Weighted average common shares outstanding:
Basic	38,186	35,218	37,877	35,184
Diluted	38,433	35,449	38,105	35,393