NET INCOME (LOSS) PER SHARE: Schedule of Earnings Per Share, Basic and Diluted (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Oct. 25, 2014	Oct. 26, 2013
Common Class A [Member]
Class of Stock [Line Items]
Net income (loss) allocated, basic	$ 2,912	$ (5,064)
Conversion of Class B to Class A shares	877	0
Effect of share-based compensation on allocated net income	2	0
Net income (loss) allocated, diluted	3,791	(5,064)
Weighted average shares outstanding, basic	9,409	9,136
Conversion of Class B to Class A shares	4,361	0
Dilutive effect of share-based compensation	19	0
Weighted average shares outstanding, diluted	13,789	9,136
Common Class B [Member]
Class of Stock [Line Items]
Net income (loss) allocated, basic	877	(1,601)
Conversion of Class B to Class A shares	0	0
Effect of share-based compensation on allocated net income	0	0
Net income (loss) allocated, diluted	$ 877	$ (1,601)
Weighted average shares outstanding, basic	4,361	4,413
Conversion of Class B to Class A shares	0	0
Dilutive effect of share-based compensation	0	0
Weighted average shares outstanding, diluted	4,361	4,413