Computation of Earnings Per Common Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Apr. 26, 2014	Apr. 27, 2013	Apr. 26, 2014	Apr. 27, 2013
Basic earnings per unit
Net income	$ 7,895	$ 7,199	$ 23,488	$ 20,522
Weighted-average number of common shares (in shares)	33,860,832	33,033,740	33,707,957	32,968,897
Basic earnings per common share	$ 0.23	$ 0.22	$ 0.70	$ 0.62
Diluted earnings per unit
Weighted-average number of common shares (in shares)	33,860,832	33,033,740	33,707,957	32,968,897
Potential common stock arising from stock options, and unvested restricted share units (in shares)	902,203	808,410	1,059,443	716,077
Total shares-diluted (in shares)	34,763,035	33,842,150	34,767,400	33,684,974
Diluted earnings per common share	$ 0.23	$ 0.21	$ 0.68	$ 0.61
Anti-dilutive weighted shares excluded from the calculation of earnings per share (in shares)	576,257	1,309,752	570,859	1,338,523