NET INCOME (LOSS) PER SHARE - Schedule of Earnings Per Share, Basic and Diluted (Details) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Apr. 23, 2016	Apr. 25, 2015	Apr. 23, 2016	Apr. 25, 2015
Common Class A [Member]
Numerator:
Net income allocated, basic	$ 4,455	$ 9,936	$ 12,563	$ 17,806
Conversion of Class B to Class A shares	1,308	2,976	3,686	5,346
Effect of share-based compensation on allocated net income	0	26	0	37
Net income allocated, diluted	$ 5,763	$ 12,938	$ 16,249	$ 23,189
Denominator:
Weighted average shares outstanding, basic (in shares)	9,559	9,449	9,566	9,423
Conversion of Class B to Class A shares (in shares)	4,319	4,361	4,319	4,361
Dilutive effect of share-based compensation (in shares)	0	107	0	50
Weighted average shares outstanding, diluted (in shares)	13,878	13,917	13,885	13,834
Common Class B [Member]
Numerator:
Net income allocated, basic	$ 1,308	$ 2,976	$ 3,686	$ 5,346
Conversion of Class B to Class A shares	0	0	0	0
Effect of share-based compensation on allocated net income	0	(19)	0	(21)
Net income allocated, diluted	$ 1,308	$ 2,957	$ 3,686	$ 5,325
Denominator:
Weighted average shares outstanding, basic (in shares)	4,319	4,361	4,319	4,361
Conversion of Class B to Class A shares (in shares)	0	0	0	0
Dilutive effect of share-based compensation (in shares)	0	0	0	0
Weighted average shares outstanding, diluted (in shares)	4,319	4,361	4,319	4,361