Share-Based Compensation (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Apr. 28, 2017	Apr. 29, 2016	Apr. 28, 2017	Apr. 29, 2016
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation	$ 2,336	$ 3,938	$ 6,347	$ 8,893
Nonvested Stock Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation	1,947	3,161	5,045	6,573
Performance-Based Market Stock Units ("MSU Grants") [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation	$ 389	$ 777	$ 1,302	$ 2,320