Leases (Narrative) (Details) - USD ($)			12 Months Ended
	Aug. 01, 2019	Aug. 01, 2018	Jul. 31, 2020	Sep. 23, 2020
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201602Member	us-gaap:AccountingStandardsUpdate201409Member
Operating lease, right-of-use assets	$ 35,825,000		$ 30,033,000
Deferred rent liability	3,023,000
Lease liabilities	$ 38,848,000		32,356,000
Annual rent			9,373,000
Chandler, Arizona | Subsequent Event
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Contract term				15 years
Executive Chairman
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Related party lease payments made			$ 649,000
Additional term of related party lease agreement as an option to exercise (in years)			10 years
Annual rent			$ 665,000