Reclamation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Asset retirement obligation
Asset retirement obligation - Beginning	$ 86,754	$ 71,763
Accretion	8,769	7,030
Additions and changes in estimates	25,370	9,389
Settlements	(2,094)	(1,428)
Asset retirement obligation - Ending	118,799	86,754
Property, Plant and Equipment [Line Items]
Additions and changes in estimates	25,370	9,389
Accrued reclamation liabilities	2,000	$ 1,900
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	7,100
Property, Plant and Equipment [Line Items]
Additions and changes in estimates	$ 7,100