Income Taxes - Tax Effects of Temporary Differences That Give Rise to Significant Portions of Deferred Tax Assets (Details) - USD ($)
$ in Thousands
Dec. 31, 2021
Dec. 31, 2020
Income Taxes    
Tax loss carryforward $ 29,496 $ 2,190
Property and equipment 12,092 10,355
Share-based compensation 1,068 4,018
Foreign tax credits 4,089 4,089
Inventory 142 79
Foreign Mining Tax 793 199
Accounts Payable 2,708 912
Employee profit sharing obligation 566  
Zinc Derivatives 608  
Other 362 377
Total deferred tax assets 51,924 22,219
Valuation allowance (36,933) (10,592)
Deferred tax assets after valuation allowance 14,991 11,627
Net deferred tax liability (13,126)  
Deferred tax liability - Property, plant and mine development $ (28,117) (11,318)
Net deferred tax (liability) asset   $ 309