Inventories, net - Schedule of inventory (Details)	Jun. 30, 2021 USD ($) oz	Dec. 31, 2020 USD ($) oz
Amount
Materials and supplies | $	$ 7,211,000	$ 6,449,000
Merrill-Crowe process plant | $	1,643,000	4,810,000
Carbon-in-column | $	1,724,000	299,000
Finished good (doré and off-site carbon) | $	8,509,000	1,309,000
Stockpiles | $	0	0
Total | $	$ 19,087,000	$ 12,867,000
Gold Ounces
Materials and supplies | oz	0	0
Merrill-Crowe process plant | oz	944	2,587
Carbon-in-column | oz	1,015	166
Finished good (doré and off-site carbon) | oz	5,010	710
Stockpiles | oz	3,818	0
Total | oz	10,787	3,463