Shareholders' Equity (Narrative) (Details) (USD $) In Millions, except Share data, unless otherwise specified	0 Months Ended		9 Months Ended
	May 22, 2013	Jan. 27, 2012	Apr. 30, 2013
Shareholders' Equity [Abstract]
Common stock authorized for repurchase			16,000,000
Stock repurchased during the period, shares			1,820,442
Stock repurchases during the period, value			$ 61.0
Average price per share			$ 33.49
Shares with remaining authorization for repurchase under stock repurchase plan			3,700,000
Percentage of stock dividend effected due to stock split		100.00%
Stock split ratio		2
Cash dividend declared per common share	$ 0.13