BASIS OF PRESENTATION and ACCOUNTING POLICIES - Disaggregated Revenues (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jan. 23, 2021	Jan. 25, 2020	Jan. 23, 2021	Jan. 25, 2020
Revenue from External Customer [Line Items]
Sales	$ 522,818	$ 437,422	$ 1,012,954	$ 844,824
Percentage of total sales	100.00%	100.00%	100.00%	100.00%
Center Store
Revenue from External Customer [Line Items]
Sales	$ 321,829	$ 272,775	$ 617,769	$ 520,832
Percentage of total sales	61.50%	62.40%	61.00%	61.60%
Fresh
Revenue from External Customer [Line Items]
Sales	$ 181,965	$ 145,500	$ 357,609	$ 286,180
Percentage of total sales	34.80%	33.30%	35.30%	33.90%
Pharmacy
Revenue from External Customer [Line Items]
Sales	$ 16,671	$ 17,710	$ 33,103	$ 35,234
Percentage of total sales	3.20%	4.00%	3.30%	4.20%
Other
Revenue from External Customer [Line Items]
Sales	$ 2,353	$ 1,437	$ 4,473	$ 2,578
Percentage of total sales	0.50%	0.30%	0.40%	0.30%