XML 110 R99.htm IDEA: XBRL DOCUMENT v3.21.1
Summary of the main accounting policies: Land, furniture and equipment (Details)
 12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Furniture equipment | Minimum    
Land, furniture and equipment:    
Useful life measured as period of time, property, plant and equipment 10 years 10 years
Furniture equipment | Maximum    
Land, furniture and equipment:    
Useful life measured as period of time, property, plant and equipment 20 years 20 years
Machinery | Minimum    
Land, furniture and equipment:    
Useful life measured as period of time, property, plant and equipment 10 years 10 years
Machinery | Maximum    
Land, furniture and equipment:    
Useful life measured as period of time, property, plant and equipment 20 years 20 years
Computer equipment | Minimum    
Land, furniture and equipment:    
Useful life measured as period of time, property, plant and equipment 20 years 20 years
Computer equipment | Maximum    
Land, furniture and equipment:    
Useful life measured as period of time, property, plant and equipment 33 years 33 years
Transportation equipment | Minimum    
Land, furniture and equipment:    
Useful life measured as period of time, property, plant and equipment 20 years 20 years
Transportation equipment | Maximum    
Land, furniture and equipment:    
Useful life measured as period of time, property, plant and equipment 25 years 25 years
Improvements to leased premises    
Land, furniture and equipment:    
Useful life measured as period of time, property, plant and equipment 10 years 10 years