Derivative Instruments and Hedging Activities, Pre-Tax Effects of Derivative Instruments on AOCIL and Income (Details) - Interest Rate Swaps [Member] - Cash Flow Hedging [Member] - USD ($) $ in Thousands	12 Months Ended
	Jul. 31, 2020	Aug. 02, 2019	Aug. 03, 2018
Interest Rate Cash Flow Hedges [Abstract]
Amount of income (loss) recognized in AOCIL on derivatives (effective portion)	$ (17,740)	$ (15,466)	$ 13,103
Interest Expense [Member]
Interest Rate Cash Flow Hedges [Abstract]
Amount of loss reclassified from AOCL into income	$ (1,165)	$ (206)	$ 3,398