Shareholders' Equity (Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions			3 Months Ended		6 Months Ended
	Mar. 03, 2017	Jan. 27, 2017	Jan. 31, 2017	Jan. 31, 2016	Jan. 31, 2017	Jan. 31, 2016	May 29, 2015
Dividends Payable [Line Items]
Cash dividend declared per common share (in usd per share)		$ 0.175
Dividends paid per share (in usd per share)			$ 0.175	$ 0.170	$ 0.350	$ 0.340
Number of shares authorized to be repurchased							14,000,000.0
Stock repurchased during the period (in shares)					1,400,000.0
Stock repurchased during the period, value					$ 51.8
Average price per share (in usd per share)					$ 37.56
Shares with remaining authorization for repurchase under stock repurchase plan (in shares)			9,100,000.0		9,100,000.0
Scenario, Forecast
Dividends Payable [Line Items]
Dividends paid per share (in usd per share)	$ 0.175