Capital Stock - Narratives (Details) - USD ($)		3 Months Ended		6 Months Ended	12 Months Ended
	Sep. 09, 2015	Apr. 29, 2017	Jan. 28, 2017	Jan. 27, 2018	Jan. 26, 2019	Jul. 29, 2017	Jul. 30, 2016	Aug. 29, 2018
Equity, Class of Treasury Stock [Line Items]
Repurchase of common stock, shares	805,000	400,000	313,006	200,000		713,006	2,511,578
Remaining authorized shares for repurchases (shares)				$ 95,200,000	$ 150,000,000		$ 100,000,000	$ 95,200,000
Shares paid for tax withholding for share based compensation				117,426	73,300	134,736	161,988
Value of shares paid for tax withholding for share based compensation				$ 12,600,000	$ 4,700,000	$ 10,800,000	$ 12,600,000
Average Price Per Share (in dollars per share)	$ 74.53	$ 94.77	$ 79.87	$ 84.38		$ 88.23	$ 67.69
Total Consideration (In thousands)		$ 37,900,000	$ 25,000,000	$ 16,875,000	$ 0	$ 62,909,000	$ 169,997,000
Shares repurchased value		$ 75,000,000.0						$ 150,000,000
Stock Repurchased and Retired During Period, Value	$ 60,000,000			16,875,000		62,909,000	169,997,000
Shares cancelled, value				$ 11,500,000		$ 42,800,000	17,100,000
Notes Offering [Member]
Equity, Class of Treasury Stock [Line Items]
Total Consideration (In thousands)							$ 110,000,000