Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Sep. 24, 2016
Deferred tax assets [Abstract]
Net operating loss carryforwards	$ 59,731	$ 60,628
Allowance for doubtful accounts	315	184
Inventory	572	457
Deferred revenue	1,041	1,091
AMT credit carryforward	1,086	1,086
Other accruals	1,883	1,179
Total deferred tax assets	64,628	64,625
Deferred tax liabilities [Abstract]
Intangible assets	1,223	775
Property, plant and equipment	4,217	5,068
Total deferred tax liabilities	5,440	5,843
Net deferred tax assets	59,188	58,782
Valuation allowance	(59,188)	(58,782)
Net deferred tax assets	$ 0	$ 0