Net Income Per Share - Computation of Basic and Diluted Net Income per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 24, 2020	Jun. 26, 2019	Jun. 24, 2020	Jun. 26, 2019
Numerator:
Net income	$ 5,499	$ 14,087	$ 9,099	$ 15,000
Denominator:
Weighted-average shares outstanding-Basic (shares)	34,836,410	37,939,912	34,747,785	38,296,807
Weighted-average shares outstanding-Diluted (shares)	35,410,198	38,580,722	35,382,607	39,043,477
Net income per share-Basic (usd per share)	$ 0.16	$ 0.37	$ 0.26	$ 0.39
Net income per share-Diluted (usd per share)	$ 0.16	$ 0.37	$ 0.26	$ 0.38
Anti-dilutive securities not considered in diluted EPS calculation (shares)	545,881	733,449	565,118	438,547