Annual report pursuant to Section 13 and 15(d)

Concentrations of Credit and Operation Risk (Details)

v3.20.4
Concentrations of Credit and Operation Risk (Details) - Accounts Receivable - Customer Concentration Risk
12 Months Ended
Dec. 26, 2020
Dec. 28, 2019
Top Customer One    
Concentration Risk [Line Items]    
Concentration risk percentage 18.00% 15.00%
Top Customer Two    
Concentration Risk [Line Items]    
Concentration risk percentage 17.00% 9.00%
Top Customer Three    
Concentration Risk [Line Items]    
Concentration risk percentage 6.00% 8.00%