Capital Stock (Details) (USD $)	9 Months Ended		12 Months Ended
	Apr. 25, 2015	Apr. 26, 2014	Jul. 26, 2014	Aug. 27, 2013
Class of Stock [Line Items]
Number of Shares Repurchased	763,768		360,900
Average Price Per Share (in dollars per share)	$ 40.18		$ 27.71
Total Consideration (Dollars in thousands)	$ 30,687,000	$ 9,999,000	$ 10,000,000
Shares Paid for Tax Withholding for Share Based Compensation	138,535	130,195
Value of Shares Paid for Tax Withholding for Share Based Compensation	4,300,000	3,600,000
Common Stock
Class of Stock [Line Items]
Remaining authorized repurchase amount	26,500,000
Common stock authorized repurchase amount				$ 40,000,000