Capital Stock (Details) - USD ($) $ / shares in Units, $ in Thousands		2 Months Ended	3 Months Ended	12 Months Ended
	Sep. 15, 2015	Sep. 11, 2015	Jul. 30, 2016	Jul. 30, 2016	Jul. 25, 2015	Jul. 26, 2014
Class of Stock [Line Items]
Number of shares repurchased	805,000			2,511,578	1,669,924	360,900
Total Consideration (Dollars in thousands)				$ 169,997	$ 87,146	$ 9,999
Average Price Per Share (in dollars per share)	$ 74.53			$ 67.69	$ 52.19	$ 27.71
Stock repurchased and retired during period, value	$ 60,000	$ 110,000		$ 169,997	$ 87,146	$ 9,999
Remaining authorized repurchase amount			$ 100,000	$ 100,000
Shares paid for tax withholding for share based compensation				161,988	145,395	136,604
Value of shares paid for tax withholding for share based compensation				$ 12,600	$ 4,700	$ 3,800
Retained Earnings
Class of Stock [Line Items]
Stock repurchased and retired during period, value			$ 17,100	$ 17,127