Net Income Per Share and Weighted Average Shares (Details) - USD ($) $ in Thousands	3 Months Ended										12 Months Ended
	Jul. 27, 2018	[1]	Apr. 27, 2018	Jan. 26, 2018	Oct. 27, 2017	Jul. 28, 2017	[1]	Apr. 28, 2017	Jan. 27, 2017	Oct. 28, 2016	Aug. 03, 2018	Jul. 28, 2017	Jul. 29, 2016
Net Income Per Share and Weighted Average Shares [Abstract]
Net income per share numerator	$ 61,354		$ 48,747	$ 91,139	$ 46,380	$ 53,893		$ 46,924	$ 52,727	$ 48,355	$ 247,620	$ 201,899	$ 189,299
Net income per share denominator [Abstract]
Basic weighted average shares outstanding (in shares)											24,011,161	24,031,810	23,945,041
Add potential dilution [Abstract]
Stock options, nonvested stock awards and units and MSU Grants (in shares)											64,453	86,478	129,232
Diluted weighted average shares outstanding (in shares)											24,075,614	24,118,288	24,074,273

[1] The Company's fourth quarter of fiscal 2018 consisted of 14 weeks.