Capital Stock (Details) (USD $)	0 Months Ended	3 Months Ended	6 Months Ended		12 Months Ended
	Mar. 15, 2012	Jan. 26, 2013	Jan. 26, 2013	Jan. 28, 2012	Jul. 28, 2012	Jul. 30, 2011
Stockholders' Equity Note [Abstract]
Common stock authorized repurchase amount	$ 40,000,000.0
Number of Shares Repurchased		1,047,000			597,700	5,389,500
Total Consideration (Dollars in thousands)		15,203,000	15,203,000	0	12,960,000	64,548,000
Average Price Per Share (in dollars per share)		$ 14.52			$ 21.68	$ 11.98
Remaining authorized repurchase amount			$ 22,800,000