Earnings Per Share - Computation of Basic and Diluted Net Income per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 25, 2020
Numerator:
Net income	$ 3,964	$ 3,600
Denominator:
Weighted-average shares outstanding-Basic (shares)	35,795,205	34,659,160
Weighted-average shares outstanding-Diluted (shares)	36,424,068	35,347,456
Net income per share-Basic (usd per share)	$ 0.11	$ 0.10
Net income per share-Diluted (usd per share)	$ 0.11	$ 0.10
Anti-dilutive securities not considered in diluted EPS calculation (shares)		474,373