Write-Downs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Impaired Long-Lived Assets Held and Used [Line Items]
Impairment of Long-Lived Assets Held-for-use	$ 0	$ 0	$ 4,446
Mining Properties and Mineral Rights [Member] | Coeur Capital [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Impairment of Long-Lived Assets Held-for-use	$ 0	$ 0	$ 4,446