Derivative Instruments and Hedging Activities, Offsetting of Derivative Assets and Liabilities (Details) - USD ($) $ in Thousands	Apr. 28, 2017	Jul. 29, 2016
Offsetting of derivative liabilities in condensed consolidated balance sheets [Abstract]
Estimated pre-tax portion of AOCL that is expected to be reclassified into earnings over the next twelve months	$ 2,780
Interest Rate Swaps [Member]
Offsetting of derivative liabilities in condensed consolidated balance sheets [Abstract]
Gross liability amounts	6,559	$ 22,250
Asset amount offset	(36)	0
Net liability amount presented in the balance sheets	6,523	22,250
Reduction in fair value of interest rate swap assets and liabilities due to adjustment related to non-performance risk	$ 112	$ 1,035