Inventories, net - Schedule of Mine site period costs (Details) - USD ($) $ in Thousands |
3 Months Ended | 9 Months Ended | ||
---|---|---|---|---|
Sep. 30, 2021 |
Sep. 30, 2020 |
Sep. 30, 2021 |
Sep. 30, 2020 |
|
Inventory Disclosure [Abstract] | ||||
Production related costs | $ 10,956 | $ 13,394 | $ 23,341 | $ 32,024 |
Capitalized depreciation and amortization | 511 | 836 | 1,104 | 2,268 |
Total | $ 11,467 | $ 14,230 | $ 24,445 | $ 34,292 |