Share-Based Compensation (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Apr. 27, 2012	Apr. 29, 2011	Apr. 27, 2012	Apr. 29, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation cost	$ 3,484	$ 2,416	$ 9,430	$ 7,335
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation cost	219	482	1,065	1,669
Nonvested Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation cost	2,774	1,626	6,839	4,997
Performance-based stock unit [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation cost	$ 491	$ 308	$ 1,526	$ 669