NET INCOME (LOSS) PER SHARE - Schedule of Earnings Per Share, Basic and Diluted (Details) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Oct. 29, 2016	Oct. 24, 2015
Common Class A [Member]
Numerator:
Net income allocated, basic	$ 3,116	$ 3,353
Conversion of Class B to Class A shares	912	983
Effect of share-based compensation on allocated net income	2	3
Net income allocated, diluted	$ 4,030	$ 4,339
Denominator:
Weighted average shares outstanding, basic (in shares)	9,592	9,577
Conversion of Class B to Class A shares (in shares)	4,319	4,319
Dilutive effect of share-based compensation (in shares)	49	5
Weighted average shares outstanding, diluted (in shares)	13,960	13,901
Common Class B [Member]
Numerator:
Net income allocated, basic	$ 912	$ 983
Conversion of Class B to Class A shares	0	0
Effect of share-based compensation on allocated net income	(1)	0
Net income allocated, diluted	$ 911	$ 983
Denominator:
Weighted average shares outstanding, basic (in shares)	4,319	4,319
Conversion of Class B to Class A shares (in shares)	0	0
Dilutive effect of share-based compensation (in shares)	0	0
Weighted average shares outstanding, diluted (in shares)	4,319	4,319