Income Taxes - Additional Information (Detail) (USD $)	2 Months Ended	3 Months Ended	8 Months Ended	9 Months Ended
	Mar. 23, 2013	Apr. 28, 2012	Mar. 23, 2013	Apr. 28, 2012	Apr. 27, 2013	Jul. 31, 2012
Schedule Of Income Taxes [Line Items]
Income tax expense	$ 10,000	$ 80,000	$ 1,416,000	$ 266,000
Tax benefit included in continuing operations	4,511,000	220,000	4,356,000	2,444,000
Total unrecognized tax benefit					1,700,000	1,700,000
Previously unrecognized tax benefit						200,000
Unrecognized tax benefit uncertain tax position					$ 500,000	$ 500,000