Note 3 - Revenue (Details Textual) - USD ($)	12 Months Ended
	Sep. 27, 2020	Sep. 29, 2019	Sep. 30, 2018	Sep. 24, 2017
Contract with Customer, Liability, Current	$ 60,271,000	$ 21,720,000
Contract with Customer, Liability, Revenue Recognized	21,549,000
Contract with Customer, Asset, after Allowance for Credit Loss, Current, Total	0	1,107,000
Accounts Receivable, before Allowance for Credit Loss	66,029,000	47,863,000
Accounts Receivable, Allowance for Credit Loss, Ending Balance	$ 13,431,000	$ 6,434,000	$ 4,806,000	$ 4,796,000