Income Taxes Components of Deferred Tax Assets and Liabilities, Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 28, 2019	Dec. 29, 2018
Operating Loss Carryforwards [Line Items]
Deferred Tax Assets, Valuation Allowance	$ 13,264	$ 16,993
Deferred Tax Liabilities, Net	91	568
Federal net operating losses	715	4,560
State net operating losses	3,362	4,142
Federal tax credit carryforwards	4,282	3,721
State tax credit carryforwards	1,688	$ 1,688
Internal Revenue Service (IRS) [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	$ 3,404
Internal Revenue Service (IRS) [Member] | Earliest Tax Year [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards and Tax Credit Carryforwards, Expiration Date	Dec. 31, 2029
Internal Revenue Service (IRS) [Member] | Latest Tax Year [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards and Tax Credit Carryforwards, Expiration Date	Dec. 31, 2040
State Taxing Authority [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	$ 63,244
State Taxing Authority [Member] | Earliest Tax Year [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards and Tax Credit Carryforwards, Expiration Date	Dec. 31, 2019
State Taxing Authority [Member] | Latest Tax Year [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards and Tax Credit Carryforwards, Expiration Date	Dec. 31, 2040