CONSOLIDATED BALANCE SHEETS (Parenthetical) - shares	Oct. 24, 2020	Jul. 25, 2020
Preferred stock shares authorized (in shares)	10,000,000	10,000,000
Preferred stock shares issued (in shares)	0	0
Common Class A [Member]
Common stock shares authorized (in shares)	20,000,000	20,000,000
Common stock shares issued (in shares)	10,988,000	10,985,000
Treasury shares	726,000	726,000
Common Class B [Member]
Common stock shares authorized (in shares)	20,000,000	20,000,000
Common stock shares issued (in shares)	4,294,000	4,294,000
Common stock shares outstanding (in shares)	4,294,000	4,294,000