SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Additional Information (Details) shares in Thousands, $ in Thousands	12 Months Ended
	Jul. 31, 2021 USD ($) store class_common_stock segment shares	Jul. 25, 2020 USD ($) shares	Jul. 28, 2019 USD ($)	Jul. 27, 2019 USD ($)
Business Acquisition [Line Items]
Number of stores acquired | store	34
Fiscal year period	371 days	364 days
Number of operating segments | segment	1
Credit and debit card receivables	$ 10,638	$ 11,535
Percentage of LIFO inventory	62.00%
LIFO reserve inventory	$ 15,321	15,101
Operating lease assets	289,461	309,756
Present value of lease liabilities	299,762
Adjustment to retained earnings from adoption of ASU 2016-02	341,473	332,320		$ 318,672
Financing obligations	(22,856)
Advertising expense	12,268	10,904
Impairment of long-lived assets	514
Indefinite-lived intangible assets	13,299	$ 15,685
Impairment of trade name	$ 2,386
Number of common stock classes | class_common_stock	2
Common stock cash dividends, percent Class A is entitled greater than Class B	54.00%
Revision of Prior Period, Accounting Standards Update, Adjustment
Business Acquisition [Line Items]
Adjustment to retained earnings from adoption of ASU 2016-02			$ 3,514
Accounting Standards Update 2016-02
Business Acquisition [Line Items]
Operating lease assets			99,415
Present value of lease liabilities			111,139
Financing obligations			17,442
Net assets for leases			$ 12,543
Class A Common Stock
Business Acquisition [Line Items]
Class A shares excluded from computation of earnings per share (in shares) | shares	102	154
Restricted Stock Units (RSUs)
Business Acquisition [Line Items]
Class A shares excluded from computation of earnings per share (in shares) | shares	392	413
Buildings
Business Acquisition [Line Items]
Useful life	30 years
Store fixtures and equipment
Business Acquisition [Line Items]
Useful life	10 years
Vehicles
Business Acquisition [Line Items]
Useful life	3 years
Wakefern
Business Acquisition [Line Items]
Demand deposits invested at related party Wakefern	$ 86,670	$ 76,259
Gourmet Garage Specialty Markets
Business Acquisition [Line Items]
Number of stores acquired | store	3