Net Income Per Share and Weighted Average Shares (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Apr. 27, 2018	Apr. 28, 2017	Apr. 27, 2018	Apr. 28, 2017
Net Income Per Share and Weighted Average Shares [Abstract]
Net income per share numerator	$ 48,747	$ 46,924	$ 186,266	$ 148,006
Net income per share denominator [Abstract]
Weighted average shares (in shares)	24,003,611	24,042,573	24,013,435	24,028,175
Add potential dilution [Abstract]
Stock options, nonvested stock awards and MSU Grants (in shares)	62,172	78,630	62,399	83,578
Diluted weighted average shares (in shares)	24,065,783	24,121,203	24,075,834	24,111,753