Shareholders' Equity (Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions		12 Months Ended
	Jul. 26, 2019	Jul. 31, 2019	Jul. 31, 2018	Jul. 31, 2017	May 31, 2019
Class of Stock [Line Items]
Number of shares authorized to be repurchased (in shares)					13,000,000
Remaining number of shares authorized to be repurchased (in shares)		12,800,000
Purchase of treasury stock		$ 129.2	$ 122.0	$ 140.4
Cash dividend declared per common share (in dollars per share)	$ 0.210	$ 0.8	$ 0.74	$ 0.71
Treasury Stock
Class of Stock [Line Items]
Stock repurchases (in shares)		2,636,554	2,642,690