Shareholders' Equity (Details) - USD ($) $ / shares in Units, $ in Millions		6 Months Ended
	Jan. 25, 2019	Jan. 31, 2019	Jan. 31, 2018
Stockholders' Equity Note [Abstract]
Number of shares authorized to be repurchased (in shares)		14,000,000
Stock repurchased during the period (in shares)		2,100,000
Stock repurchased during the period		$ 102.0	$ 62.9
Shares with remaining authorization for repurchase under stock repurchase plan (in shares)		2,400,000
Cash dividend declared per common share (in usd per share)	$ 0.190