Inventory and Ore on Leach Pads (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Inventory Disclosure [Abstract]
Inventory, Finished Goods, Net of Reserves	$ 2,740	$ 2,909
Other Inventory, Net of Reserves	11,762	14,788
Inventory, Supplies, Net of Reserves	37,832	33,513
Inventory	52,334	51,210
Ore on Leach Pad, Current	74,803	74,866
Ore on leach pads, noncurrent	78,302	81,963
Inventory, Ore Stockpiles on Leach Pads, Gross	153,105	156,829
Inventory and Ore on Leach Pads	222,075	213,703
Long-Term Inventory Stockpile	$ 16,636	$ 5,664