Income Taxes (Details) - USD ($)			3 Months Ended		6 Months Ended
	Jun. 29, 2020	Mar. 27, 2020	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Effective tax rate of provision for income taxes difference from federal statutory rate
Income tax benefit			$ 1,129,000	$ (1,629,000)	$ 1,305,000	$ (1,445,000)
Effective income tax rate (as a percent)			6.20%	(5.30%)	3.40%	(3.20%)
Foreign income tax benefit				$ (1,100,000)		$ (1,100,000)
Federal statutory income tax rate (as a percent)			21.00%	21.00%	21.00%	21.00%
Net Operating Loss Carryback		5 years
Deduction of Taxable Income, Percentage		80.00%
Amount of income limit for California Net Operating Loss deductions	$ 1,000,000
Amount of California tax offset for business credit	$ 5,000,000