Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Jul. 28, 2017	Apr. 28, 2017	Jan. 27, 2017	Oct. 28, 2016	Jul. 29, 2016	Apr. 29, 2016	Jan. 29, 2016	Oct. 30, 2015	Jul. 28, 2017	Jul. 29, 2016	Jul. 31, 2015
Quarterly Financial Data (Unaudited) [Abstract]
Total revenue	$ 743,226	$ 700,410	$ 772,682	$ 709,971	$ 745,584	$ 700,136	$ 764,002	$ 702,629	$ 2,926,289	$ 2,912,351	$ 2,842,284
Store operating income	119,749	107,478	117,513	109,832	114,375	103,419	106,032	99,627	454,572	423,453	402,424
Income before income taxes	79,672	68,089	79,058	72,068	74,107	63,592	66,956	61,764	298,887	266,419	238,201
Net income	$ 53,893	$ 46,924	$ 52,727	$ 48,355	$ 51,023	$ 49,169	$ 48,242	$ 40,865	$ 201,899	$ 189,299	$ 163,903
Net income per share - basic (in dollars per share)	$ 2.24	$ 1.95	$ 2.19	$ 2.01	$ 2.13	$ 2.05	$ 2.02	$ 1.71	$ 8.40	$ 7.91	$ 6.85
Net income per share - diluted (in dollars per share)	$ 2.23	$ 1.95	$ 2.19	$ 2.01	$ 2.12	$ 2.04	$ 2.01	$ 1.70	$ 8.37	$ 7.86	$ 6.82