Basis of Presentation - Additional Information (Details) - USD ($) $ in Thousands	Jun. 27, 2020	Dec. 28, 2019		Jun. 29, 2019	Dec. 29, 2018
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Cash and cash equivalents	$ 11,624	$ 12,653		$ 15,633	$ 21,194
Accumulated deficit	$ 55,046	$ 50,615	[1]

[1] Derived from the audited consolidated financial statements included in the Annual Report on Form 10-K filed with the SEC for the year ended December 28, 2019.