Consolidated Condensed Statements of Income (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Nov. 30, 2011	Nov. 30, 2010	Nov. 30, 2011	Nov. 30, 2010
Sales revenue, net	$ 338,785	$ 205,001	$ 887,672	$ 539,977
Cost of goods sold	205,603	112,256	532,295	294,529
Gross profit	133,182	92,745	355,377	245,448
Selling, general, and administrative expense	91,354	61,205	252,546	163,020
Operating income before impairments	41,828	31,540	102,831	82,428
Asset impairment charges				501
Operating income	41,828	31,540	102,831	81,927
Nonoperating income (expense), net	190	156	(325)	490
Interest expense	(2,958)	(2,081)	(9,652)	(6,377)
Income before income taxes	39,060	29,615	92,854	76,040
Income tax expense (benefit):
Current	4,222	2,191	6,656	7,365
Deferred	1,959	361	5,121	(248)
Net income	$ 32,879	$ 27,063	$ 81,077	$ 68,923
Earnings per share:
Basic (in dollars per share)	$ 1.04	$ 0.88	$ 2.59	$ 2.25
Diluted (in dollars per share)	$ 1.04	$ 0.86	$ 2.56	$ 2.20
Weighted average shares of common stock used in computing net earnings per share:
Basic (in shares)	31,592	30,644	31,246	30,640
Diluted (in shares)	31,666	31,297	31,685	31,293