Net Income Per Share and Weighted Average Shares (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Apr. 27, 2012	Apr. 29, 2011	Apr. 27, 2012	Apr. 29, 2011
Net Income Per Share and Weighted Average Shares [Abstract]
Net income per share numerator	$ 18,974	$ 15,154	$ 68,385	$ 67,665
Net income per share denominator: [Abstract]
Basic (in shares)	23,132,730	23,048,279	22,990,544	23,039,388
Add potential dilution: [Abstract]
Stock options and nonvested stock and stock awards (in shares)	403,035	554,054	338,686	665,767
Diluted weighted average shares outstanding (in shares)	23,535,765	23,602,333	23,329,230	23,705,155