Condensed Consolidated Statements of Earnings (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Oct. 31, 2011	Oct. 31, 2010	Oct. 31, 2011	Oct. 31, 2010
Condensed Consolidated Statements of Earnings [Abstract]
Net sales	$ 821,767	$ 681,729	$ 2,455,497	$ 1,984,075
Cost of sales	345,918	283,158	1,021,258	832,774
Gross profit	475,849	398,571	1,434,239	1,151,301
Selling, general and administrative expenses	329,672	300,993	1,011,556	834,700
Earnings from operations	146,177	97,578	422,683	316,601
Interest and other expenses, net	10,393	12,997	30,159	36,256
Earnings from operations before income taxes	135,784	84,581	392,524	280,345
Provision for income taxes	46,095	29,502	131,729	93,166
Net earnings	$ 89,689	$ 55,079	$ 260,795	$ 187,179
Earnings per share:
Basic	$ 0.71	$ 0.44	$ 2.04	$ 1.48
Diluted	$ 0.70	$ 0.43	$ 2.02	$ 1.46
Weighted-average number of common shares:
Basic	127,210	126,176	127,614	126,591
Diluted	128,812	127,905	129,329	128,277