Income Taxes - Additional Information (Detail) - USD ($)	Sep. 24, 2016	Sep. 26, 2015
Schedule Of Income Taxes [Line Items]
State tax net operating losses	$ 101,800,000
Foreign losses	400,000
State income tax credits	3,600,000
Valuation allowances	6,583,000	$ 6,205,000
Penalties were accrued related to uncertain tax positions	0	0
Unrecognized tax benefit may be recognized within twelve months as a result of a settlement	200,000
Maximum [Member]
Schedule Of Income Taxes [Line Items]
Accrued interest	$ 100,000	$ 100,000