NET INCOME (LOSS) PER SHARE - Schedule of Earnings Per Share, Basic and Diluted (Details) shares in Thousands, $ in Thousands	3 Months Ended
	Oct. 26, 2019 USD ($) shares	Oct. 27, 2018 USD ($) shares
Class of Stock [Line Items]
Conversion of Stock, Conversion Ratio	1
Common Class A [Member]
Numerator:
Net income allocated, basic	$ 1,939	$ 4,739
Conversion of Class B to Class A shares	558	1,361
Effect of share-based compensation on allocated net income	(2)
Net income allocated, diluted	$ 2,495	$ 6,100
Denominator:
Weighted average shares outstanding, basic (in shares) | shares	9,770	9,732
Conversion of Class B to Class A shares (in shares) | shares	4,294	4,304
Weighted average shares outstanding, diluted (in shares) | shares	14,064	14,036
Common Class B [Member]
Numerator:
Net income allocated, basic	$ 558	$ 1,361
Conversion of Class B to Class A shares	0	0
Effect of share-based compensation on allocated net income	(1)
Net income allocated, diluted	$ 557	$ 1,361
Denominator:
Weighted average shares outstanding, basic (in shares) | shares	4,294	4,304
Conversion of Class B to Class A shares (in shares) | shares	0	0
Weighted average shares outstanding, diluted (in shares) | shares	4,294	4,304