Income Taxes Components of Deferred Tax Assets and Liabilities, Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 29, 2018	Dec. 30, 2017
Operating Loss Carryforwards [Line Items]
Deferred Tax Assets, Valuation Allowance	$ 16,993	$ 12,994
Deferred Tax Liabilities, Net	568	1,105
Federal net operating losses	4,560	3,204
State net operating losses	4,142	4,196
Federal tax credit carryforwards	3,721	3,365
State tax credit carryforwards	1,688	$ 1,963
Internal Revenue Service (IRS) [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	$ 21,712
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, 2039
State Taxing Authority [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	$ 76,797
State Taxing Authority [Member] | Earliest Tax Year [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards and Tax Credit Carryforwards, Expiration Date	Dec. 31, 2018
State Taxing Authority [Member] | Latest Tax Year [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards and Tax Credit Carryforwards, Expiration Date	Dec. 31, 2039