Derivative Instruments and Hedging Activities, Changes in AOCL, Net of Tax, Related to Interest Rate Swaps (Details) - USD ($) $ in Thousands	12 Months Ended
	Jul. 29, 2016	Jul. 31, 2015	Aug. 01, 2014
Changes in AOCL, net of tax, related to interest rate swaps [Roll Forward]
Balance	$ 538,268	$ 528,641	$ 484,026
Other comprehensive (loss) income before reclassifications	(6,683)	5,955	6,836
Amounts reclassified from AOCL into earnings	(3,332)	(4,947)	(4,957)
Other comprehensive (loss) income, net of tax	(10,015)	1,008	1,879
Balance	526,443	538,268	528,641
Accumulated Other Comprehensive Loss [Member]
Changes in AOCL, net of tax, related to interest rate swaps [Roll Forward]
Balance	(3,725)	(4,733)	(6,612)
Balance	$ (13,740)	$ (3,725)	$ (4,733)