Inventory and Ore on Leach Pads (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Inventory Disclosure [Abstract]
Inventory, Finished Goods, Net of Reserves	$ 8,245	$ 17,994
Other Inventory, Net of Reserves	24,537	47,228
Inventory, Supplies, Net of Reserves	39,547	40,804
Inventory	72,329	106,026
Ore on Leach Pad, Current	78,801	64,167
Ore on leach pads, noncurrent	69,805	67,231
Inventory, Ore Stockpiles on Leach Pads, Gross	148,606	131,398
Inventory and Ore on Leach Pads	$ 220,935	$ 237,424