Share-Based Compensation (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jan. 30, 2015	Jan. 31, 2014	Jan. 30, 2015	Jan. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation cost	$ 3,595	$ 1,426	$ 6,330	$ 4,246
Nonvested Stock Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation cost	2,826	832	4,982	3,342
Performance-Based Market Stock Units ("MSU Grants") [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation cost	$ 769	$ 594	$ 1,348	$ 904