CONSOLIDATED STATEMENTS OF INCOME (USD $)	12 Months Ended
	Jan. 31, 2012	Jan. 31, 2011	Jan. 31, 2010
CONSOLIDATED STATEMENTS OF INCOME [Abstract]
Net sales	$ 100,161,392	$ 88,865,426	$ 80,132,493
Cost of goods sold	64,792,385	56,587,326	52,755,941
Gross profit	35,369,007	32,278,100	27,376,552
Operating expenses
Selling	12,017,123	11,674,270	9,741,528
General and administrative	12,760,600	11,633,509	11,122,469
Total selling, general and administrative expenses	24,777,723	23,307,779	20,863,997
Income from operations	10,591,284	8,970,321	6,512,555
Interest expense	(191,181)	(212,470)	(224,143)
Other income	434,207	362,046	260,177
Income before taxes	10,834,310	9,119,897	6,548,589
Provision for taxes	3,700,609	2,980,765	2,108,778
Net income	$ 7,133,701	$ 6,139,132	$ 4,439,811
Earnings per share
Basic	$ 0.49	$ 0.42	$ 0.30
Diluted	$ 0.48	$ 0.42	$ 0.30
Average number of common and common equivalent shares outstanding, Basic	14,662,055	14,629,215	14,602,276
Average number of common and common equivalent shares outstanding, Diluted	14,774,692	14,758,659	14,675,735