Capital Stock - Narratives (Details) - USD ($)	3 Months Ended		6 Months Ended	12 Months Ended
	Apr. 29, 2017	Jan. 28, 2017	Jan. 27, 2018	Jan. 25, 2020	Jan. 26, 2019	Jul. 29, 2017	Aug. 29, 2018	Jul. 30, 2016
Stockholders' Equity Note [Abstract]
Shares repurchased value	$ 75,000,000.0						$ 150,000,000.0
Remaining authorized shares for repurchases (shares)			$ 95,200,000					$ 100,000,000.0
Average Price Per Share (in dollars per share)	$ 94.77	$ 79.87	$ 84.38			$ 88.23
Total Consideration (In thousands)	$ 37,900,000	$ 25,000,000.0	$ 16,875,000	$ 0	$ 0	$ 62,909,000
Repurchase of common stock, shares	400,000	313,006	200,000			713,006
Shares paid for tax withholding for share based compensation			117,426	36,426	73,300	134,736
Value of shares paid for tax withholding for share based compensation			$ 12,600,000	$ 1,700,000	$ 4,700,000	$ 10,800,000
Shares cancelled, value			$ 42,800,000		$ 11,500,000