RELATED PARTY INFORMATION - WAKEFERN (Details) - Wakefern - USD ($) $ in Thousands	12 Months Ended
	Jul. 28, 2018	Jul. 29, 2017	Aug. 15, 2017
Related Party Transaction [Line Items]
Ownership interest in Wakefern	12.80%
Purchase obligation, as a percentage of merchandise requirements	85.00%
Purchase obligation period	10 years
Percentage of stockholders to request termination	75.00%
Indebtedness to Wakefern	$ 114
Vendor allowances and rebates	28,536	$ 30,048
Support services incurred charges	33,037	32,135
Notes receivable from Wakefern	47,081
Demand deposits invested at related party Wakefern	63,413	60,037
Interest income earned on investments related entity	$ 3,806	$ 2,841
Related Party Note Receivable Maturing February 2019 and August 2022
Related Party Transaction [Line Items]
Basis spread on variable rate (as a percent)	1.25%
Related Party Note Receivable Maturing February 2019
Related Party Transaction [Line Items]
Notes receivable from Wakefern	$ 23,952
Related Party Note Receivable Maturing August 2022
Related Party Transaction [Line Items]
Notes receivable from Wakefern	23,129
Proceeds from notes receivable	$ 22,000
Related Party Note Receivable Maturing August 2017
Related Party Transaction [Line Items]
Notes receivable from Wakefern			$ 22,142
Basis spread on variable rate (as a percent)	0.25%
Insure-Rite Ltd.
Related Party Transaction [Line Items]
Investment in Insure-Rite, Ltd	7.80%