Net Income Per Share and Weighted Average Shares (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Feb. 01, 2013	Jan. 27, 2012	Feb. 01, 2013	Jan. 27, 2012
Net Income Per Share and Weighted Average Shares [Abstract]
Net income per share numerator	$ 35,168	$ 25,609	$ 58,360	$ 49,411
Net income per share denominator: [Abstract]
Basic weighted average shares outstanding (in shares)	23,711,235	22,968,002	23,644,405	22,919,451
Add potential dilution: [Abstract]
Stock options and nonvested stock awards and MSU Grants (in shares)	234,001	338,175	222,026	306,512
Diluted weighted average shares outstanding (in shares)	23,945,236	23,306,177	23,866,431	23,225,963