Reclamation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Asset retirement obligation
Asset retirement obligation - Beginning	$ 118,799	$ 86,754
Accretion	11,037	8,769
Additions and changes in estimates	6,880	25,370
Settlements	(3,208)	(2,094)
Asset retirement obligation - Ending	133,508	118,799
Property, Plant and Equipment [Line Items]
Additions and changes in estimates	6,880	25,370
Accrued reclamation liabilities, former mines	2,000	2,000
Palmarejo [Member]
Asset retirement obligation
Additions and changes in estimates		17,100
Property, Plant and Equipment [Line Items]
Additions and changes in estimates		17,100
Rochester [Member]
Asset retirement obligation
Additions and changes in estimates		1,200
Property, Plant and Equipment [Line Items]
Additions and changes in estimates		1,200
Silvertip [Member]
Asset retirement obligation
Additions and changes in estimates	6,500	7,100
Property, Plant and Equipment [Line Items]
Additions and changes in estimates	$ 6,500	$ 7,100