Note 9 - Employee Benefit Plans - Net Periodic Pension Costs and Related Components (Details) - Supplemental Employee Retirement Plan [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 28, 2020	Mar. 30, 2019	Mar. 28, 2020	Mar. 30, 2019
Interest cost	$ 82	$ 96	$ 167	$ 192
Service cost	76	74	162	148
Recognized net actuarial loss	65	35	140	70
Net periodic pension cost	$ 223	$ 205	$ 469	$ 410