Quarterly Financial Information - Unaudited (Schedule of Quarterly Financial Information) (Details) (USD $)	3 Months Ended																12 Months Ended
	Apr. 26, 2013		Jan. 25, 2013		Oct. 26, 2012		Jul. 27, 2012		Apr. 27, 2012		Jan. 27, 2012		Oct. 28, 2011		Jul. 29, 2011		Apr. 26, 2013		Apr. 27, 2012		Apr. 29, 2011
Quarterly Financial Information - Unaudited [Abstract]
Net sales	$ 68,343,567		$ 62,700,033		$ 62,955,645		$ 60,321,172		$ 57,609,009		$ 54,536,585		$ 53,695,061		$ 52,662,076		$ 254,320,417		$ 218,502,731		$ 190,464,398
Gross profit	61,984,502		57,332,815		57,785,841		55,309,995		53,134,864		50,437,096		49,534,397		45,740,042		232,413,153		198,846,399		167,444,366
Net income	$ 11,532,071		$ 13,183,494		$ 13,566,904		$ 8,075,033		$ 10,663,220		$ 9,502,184		$ 9,027,774		$ 6,884,554		$ 46,357,502		$ 36,077,732		$ 46,725,710
Diluted income per share (in Dollars per Share)	$ 0.41	[1]	$ 0.47	[1]	$ 0.48	[1]	$ 0.29	[1]	$ 0.38	[1]	$ 0.34	[1]	$ 0.32	[1]	$ 0.24	[1]	$ 1.66	[1]	$ 1.28	[1]	$ 1.64

[1] EPS in each quarter is computed using the weighted-average number of shares outstanding during that quarter while EPS for the full year is computed using the weighted-average number of shares outstanding during the year. Thus, the sum for the four quarters’ EPS does not necessarily equal the full year EPS