Embedded Derivatives (Details)	6 Months Ended
	Jun. 30, 2020 $ / t $ / oz t oz
Gold
Embedded Derivative [Line Items]
Under contract | oz	1,323
Average forward price | $ / oz	1,729
Silver
Embedded Derivative [Line Items]
Under contract | oz	140,522
Average forward price | $ / oz	17.44
Copper
Embedded Derivative [Line Items]
Under contract | t	174
Average forward price | $ / t	5,744
Lead
Embedded Derivative [Line Items]
Under contract | t	1,185
Average forward price | $ / t	1,728
Zinc
Embedded Derivative [Line Items]
Under contract | t	2,763
Average forward price | $ / t	1,991