Derivative Instruments and Hedging Activities, Amounts Reclassified out of AOCL Related to Interest Rate Swaps (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Jul. 28, 2017	Apr. 28, 2017	Jan. 27, 2017	Oct. 28, 2016	Jul. 29, 2016	Apr. 29, 2016	Jan. 29, 2016	Oct. 30, 2015	Jul. 28, 2017	Jul. 29, 2016	Jul. 31, 2015
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest expense									$ (14,271)	$ (14,052)	$ (16,679)
Provision for income taxes									(96,988)	(77,120)	(74,298)
Net of tax	$ 53,893	$ 46,924	$ 52,727	$ 48,355	$ 51,023	$ 49,169	$ 48,242	$ 40,865	201,899	189,299	163,903
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Provision for income taxes									1,592	2,063	3,105
Net of tax									(2,571)	(3,332)	(4,947)
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member] | Interest Rate Swaps [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest expense									$ (4,163)	$ (5,395)	$ (8,052)