Note 3 - Business Combination (Details Textual) - USD ($)		3 Months Ended	9 Months Ended
	Mar. 16, 2020	Jul. 03, 2021	Jul. 03, 2021	Apr. 03, 2021	Jan. 02, 2021	Oct. 03, 2020	Jun. 27, 2020	Mar. 28, 2020
Disposal Group, Including Discontinued Operation, Assets, Total		$ 6,306,000	$ 6,306,000			$ 7,778,000
Restructuring Reserve, Ending Balance		20,000	20,000	$ 27,000	$ 47,000	171,000	$ 120,000	$ 145,000
Restructuring and Related Cost, Expected Cost Remaining		300,000	300,000
Accrued Expenses [Member]
Restructuring Reserve, Ending Balance		20,000	20,000			$ 171,000
Summerville Facility Acquired in STM Acquisition [Member]
Disposal Group, Including Discontinued Operation, Assets, Total		6,300,000	6,300,000
Summerville Facility Acquired in STM Acquisition [Member] | Restructuring Charges [Member]
Impairment of Long-Lived Assets to be Disposed of		$ 1,400,000	$ 1,400,000
STM Acquisition [Member]
Business Combination, Consideration Transferred, Total	$ 19,400,000
Business Combination, Consideration Transferred, Liabilities Incurred	$ 1,000,000.0