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Commitments and contingencies Details (Details)
$ in Thousands
9 Months Ended 12 Months Ended
Sep. 26, 2020
USD ($)
Dec. 31, 2019
Dec. 31, 2018
Loss contingency, number of claims alleged 3    
Loss Contingency, New Claims Filed, Number 4    
Loss contingency, complaints served 1    
Credit Concentration Risk [Member]      
Concentration risk, percentage   12.00% 12.00%
Customer Concentration Risk [Member]      
Pre-petition accounts receivable $ 15,000    
Former Davey employee defendants [Member]      
Loss contingency, number of defendants 1    
Wolf employee defendants [Member]      
Loss contingency, number of defendants 2    
Former Wolf employee defendants [Member]      
Loss contingency, number of defendants 1    
Employee and former employee defendants [Member]      
Loss contingency, number of defendants 4    
Former Wolf employee defendants indicted [Member]      
Loss contingency, number of defendants 2    
Other individuals [Member]      
Loss contingency, number of defendants 1