Provision for Taxes - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 28, 2019	Dec. 29, 2018	Dec. 30, 2017
State, net of federal benefit, research tax credit carryforwards	$ 346
Tax Cuts and Jobs Act, Income Tax Expense (Benefit)		$ 600	$ (3,000)
Transition tax payable		1,100
Domestic Tax Authority [Member]
Income taxes payable	41
Transition tax payable	387
Income taxes receivable	$ 204	943
State and Local Jurisdiction [Member]
Income taxes receivable		$ 139