Note 10 - Per Share Data - Weighted Average Number of Common Shares (Details) - shares	3 Months Ended		6 Months Ended
	Jun. 27, 2020	Jun. 29, 2019	Jun. 27, 2020	Jun. 29, 2019
Basic weighted average shares outstanding (in shares)	12,621,593	12,880,179	12,866,571	12,868,356
Dilutive effect of outstanding restricted share units (in shares)	21,466	57,932	27,009	50,727
Weighted average dilutive shares outstanding (in shares)	12,643,059	12,938,111	12,893,580	12,919,083