Note 10 - Per Share Data - Weighted Average Number of Common Shares (Details) - shares	3 Months Ended
	Mar. 28, 2020	Mar. 30, 2019
Basic weighted average shares outstanding (in shares)	13,111,550	12,856,533
Dilutive effect of outstanding restricted share units (in shares)	32,534	44,301
Weighted average dilutive shares outstanding (in shares)	13,144,084	12,900,834