Derivative Financial Instruments - Summary of Provisionally Priced Sales (Details) - Gold concentrates sales agreements $ in Thousands	Mar. 31, 2021 USD ($) oz $ / oz
2018
Derivative instruments Settlement
Derivative average price | $ / oz	1,782
Notional Amount Derivative | $	$ 21,630
Outstanding Provisionally Priced Sales Consists of Gold | oz	12,137
2022 and Thereafter
Derivative instruments Settlement
Derivative average price | $ / oz	0
Notional Amount Derivative | $	$ 0
Outstanding Provisionally Priced Sales Consists of Gold | oz	0