Composition Of Certain Financial Statement Captions (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 28, 2018	Sep. 29, 2017
Composition Of Certain Financial Statement Captions [Line Items]
Raw materials	$ 6,095	$ 6,812
Document Period End Date	Sep. 28, 2018
Other Noncurrent Assets [Member]
Composition Of Certain Financial Statement Captions [Line Items]
Raw materials	$ 2,600	$ 1,800