SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Net Income Per Share (Details) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Jul. 30, 2016 USD ($) class_common_stock $ / shares shares	Jul. 25, 2015 USD ($) $ / shares shares	Jul. 26, 2014 USD ($) $ / shares shares
Accounting Policies [Abstract]
Number of common stock classes | class_common_stock	2
Common stock cash dividends, percent Class A is entitled greater than Class B	54.00%
Class A Common Stock
Numerator:
Net income allocated, basic | $	$ 18,967	$ 23,050	$ 3,788
Conversion of Class B to Class A shares | $	5,563	6,885	1,141
Effect of share-based compensation on allocated net income | $	0	46	(20)
Net income allocated, diluted | $	$ 24,530	$ 29,981	$ 4,909
Denominator:
Weighted average shares outstanding, basic (in shares) | shares	9,567	9,459	9,258
Conversion of Class B to Class A shares (in shares) | shares	4,319	4,353	4,374
Dilutive effect of share-based compensation (in shares) | shares	0	48	62
Weighted average shares outstanding, diluted (in shares) | shares	13,886	13,860	13,694
Net income per share
Basic (in dollars per share) | $ / shares	$ 1.98	$ 2.44	$ 0.41
Diluted (in dollars per share) | $ / shares	$ 1.77	$ 2.16	$ 0.36
Class B Common Stock
Numerator:
Net income allocated, basic | $	$ 5,563	$ 6,885	$ 1,141
Conversion of Class B to Class A shares | $	0	0	0
Effect of share-based compensation on allocated net income | $	(3)	(23)	(11)
Net income allocated, diluted | $	$ 5,560	$ 6,862	$ 1,130
Denominator:
Weighted average shares outstanding, basic (in shares) | shares	4,319	4,353	4,374
Conversion of Class B to Class A shares (in shares) | shares	0	0	0
Dilutive effect of share-based compensation (in shares) | shares	0	0	0
Weighted average shares outstanding, diluted (in shares) | shares	4,319	4,353	4,374
Net income per share
Basic (in dollars per share) | $ / shares	$ 1.29	$ 1.58	$ 0.26
Diluted (in dollars per share) | $ / shares	$ 1.29	$ 1.58	$ 0.26