Inventories, net - Schedule of inventory, Ore on leach pads (Details) $ in Thousands	Sep. 30, 2021 USD ($) oz	Dec. 31, 2020 USD ($) oz
Amount
Ore on leach pads, current | $	$ 29,588	$ 38,041
Ore on leach pads, non-current | $	6,142	7,243
Total | $	$ 35,730	$ 45,284
Gold Ounces
Ore on leach pads, current | oz	17,454	21,869
Ore on leach pads, non-current | oz	3,612	4,164
Total | oz	21,066	26,033