Net Income Per Share (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 26, 2020	Jun. 27, 2020	Mar. 28, 2020	Sep. 28, 2019	Jun. 29, 2019	Mar. 30, 2019	Sep. 26, 2020	Sep. 28, 2019
Net Income (Loss) Available to Common Stockholders, Diluted [Abstract]
Net income	$ 5,403	$ 5,931	$ 6,468	$ 5,739	$ 5,580	$ 4,665	$ 17,802	$ 15,984
Less: net income attributable to participating shares	22			12			53	47
Net income available to common shareholders	$ 5,381			$ 5,727			$ 17,749	$ 15,937
Reconciliation of basic to diluted weighted average shares of common stock outstanding
Basic weighted average shares outstanding	7,771,000			7,769,000			7,780,000	7,903,000
Dilutive stock options and restricted stock units	163,000			281,000			184,000	302,000
Diluted weighted average shares outstanding	7,934,000			8,050,000			7,964,000	8,205,000
Calculation of common stock equivalents for purposes of computing diluted weighted average shares outstanding
Anti-dilutive securities excluded from EPS computation (in shares)	76,399,000			63,164,000			62,808,000	47,169,000