Net Income Per Share and Weighted Average Shares (Details) - USD ($) $ in Thousands	3 Months Ended
	Oct. 30, 2015	Oct. 31, 2014
Net Income Per Share and Weighted Average Shares [Abstract]
Net income per share numerator	$ 40,865	$ 34,024
Net income per share denominator [Abstract]
Weighted average shares (in shares)	23,956,554	23,862,195
Add potential dilution [Abstract]
Stock options, nonvested stock awards and MSU Grants (in shares)	116,498	139,243
Diluted weighted average shares (in shares)	24,073,052	24,001,438