| Schedule of earnings per share, basic and diluted | 
  | 
      | 
  | 
  | 
  | 
      | 
  | 
  | 
    |   | 
  | 
    Three Months Ended  March 31,  | 
  | 
  
    |   | 
  | 
    2023  | 
  | 
  | 
    2022  | 
  | 
  
    | Weighted-average common shares outstanding
    – basic | 
  | 
      | 
23,866,821 | 
  | 
  | 
      | 
23,909,115 | 
  | 
  
    | Dilutive effect of restricted stock units and stock options | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  
    | Weighted-average common shares outstanding – diluted | 
  | 
      | 
23,866,821 | 
  | 
  | 
      | 
23,909,115 | 
  | 
  
    | Restricted stock units excluded from the computation of diluted loss per share because the effect of inclusion would have been anti-dilutive | 
  | 
      | 
571,250 | 
  | 
  | 
      | 
1,171,250 | 
  |