Write-Downs (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Impaired Long-Lived Assets Held and Used [Line Items]
Write-downs	$ 0	$ 0	$ 250,814
Property, Plant and Equipment [Member] | Silvertip [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Write-downs			43,600
Mine Development [Member] | Silvertip [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Write-downs			201,500
Other Noncurrent Assets [Member] | Silvertip [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Write-downs			$ 5,700