Supplementary Cash Flow Information (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2021
Dec. 31, 2020
Dec. 31, 2019
Supplementary Cash Flow Information      
Unrealized loss (gain) on gold and silver rounds/bullion $ 53 $ (170) $ (671)
Realized loss (gain) on gold and silver rounds/bullion 2 (1,003)  
Unrealized foreign currency exchange (gain) loss 493 105 (19)
Loss on disposition of fixed assets 37 3 12
Increase (decrease) in reserve for inventory 175 (148) 885
Stock based compensation related to restructuring   809  
Unrealized loss on zinc zero cost collar 1,844    
Other 105   98
Total other operating adjustments $ 2,709 $ (404) $ 305