Derivative Financial Instruments - Summary of Provisionally Priced Sales (Details) - Gold concentrates sales agreements $ in Thousands	Dec. 31, 2020 USD ($) oz $ / oz
2018
Derivative instruments Settlement
Derivative average price | $ / oz	1,852
Notional Amount Derivative | $	$ 28,243
Outstanding Provisionally Priced Sales Consists of Gold | oz	15,248
2022 and Thereafter
Derivative instruments Settlement
Derivative average price | $ / oz	0
Notional Amount Derivative | $	$ 0
Outstanding Provisionally Priced Sales Consists of Gold | oz	0