Stock Based Compensation - Summary of Stock Options Outstanding, Vested, Expected to Vest and Exercisable (Details) - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended
	Jun. 30, 2018	Dec. 30, 2017
Stock options outstanding, exercisable and expected to vest
Options outstanding, Number of Shares	890,323	857,311
Options vested and expected to vest, Number of Shares	826,224
Options exercisable, Number of Shares	284,733
Options outstanding, Weighted Average Exercise Price	$ 9.17	$ 9.49
Options vested and expected to vest, Weighted Average Exercise Price	9.17
Options exercisable, Weighted Average Exercise Price	$ 8.72
Options outstanding, Weighted Average Remaining Contractual Life (Years)	5 years 1 month 6 days
Options vested and expected to vest, Weighted Average Remaining Contractual Life (Years)	5 years 10 days
Options exercisable, Weighted Average Remaining Contractual Life (Years)	3 years 3 months 18 days
Options outstanding, Aggregate Intrinsic Value	$ 225
Options vested and expected to vest, Aggregate Intrinsic Value	214
Options exercisable, Aggregate Intrinsic Value	$ 147