Income Per Share (Schedule Of Earnings Per Share, Basic And Diluted) (Details) (USD $)	3 Months Ended		9 Months Ended
	Jan. 25, 2013	Jan. 27, 2012	Jan. 25, 2013	Jan. 27, 2012
Income Per Share [Abstract]
Net income	$ 13,183,494	$ 9,502,184	$ 34,825,431	$ 25,414,512
Add effect of Convertible Notes	0	(5,231)	0	71,795
Diluted income	$ 13,183,494	$ 9,496,953	$ 34,825,431	$ 25,486,307
Basic weighted average shares outstanding (in Shares)	27,736,639	27,559,729	27,626,387	27,912,114
Stock options (in Shares)	387,794	364,738	419,050	312,831
Convertible Notes (in Shares)	0	110,048	0	149,839
Diluted weighted average shares outstanding (in Shares)	28,124,433	28,034,515	28,045,437	28,374,784
Basic income per share (in Dollars per Share)	$ 0.48	$ 0.34	$ 1.26	$ 0.91
Diluted income per share (in Dollars per Share)	$ 0.47	$ 0.34	$ 1.24	$ 0.90