Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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The current period expense charged against earnings on long-lived, physical assets not used in production, and which are not intended for resale, to allocate or recognize the cost of such assets over their useful lives; or to record the reduction in book value of an intangible asset over the benefit period of such asset; or to reflect consumption during the period of an asset that is not used in production.

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Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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Amount after accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business to produce goods and services and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

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Plant, Equipment, and Mine Development, Net (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Plant, Equipment, and Mine Development, Net
Property and equipment, gross	$ 70,915		$ 68,415
Less: accumulated depreciation and amortization	(19,342)		(17,208)
Total	51,573		51,207
Process equipment
Plant, Equipment, and Mine Development, Net
Property and equipment, gross	15,144		14,770
Leach pads
Plant, Equipment, and Mine Development, Net
Property and equipment, gross	11,190		11,190
Depreciation and amortization	$ 2,100	$ 0
Buildings and leashold improvements
Plant, Equipment, and Mine Development, Net
Depreciation Life	10 years
Property and equipment, gross	$ 10,507		10,507
Restart leach pads
Plant, Equipment, and Mine Development, Net
Depreciation Life	18 months
Property and equipment, gross	$ 6,241		6,229
Mine equipment
Plant, Equipment, and Mine Development, Net
Property and equipment, gross	4,847		4,716
Vehicles
Plant, Equipment, and Mine Development, Net
Property and equipment, gross	$ 184		136
Furniture and office equipment
Plant, Equipment, and Mine Development, Net
Depreciation Life	7 years
Property and equipment, gross	$ 264		129
Mine development
Plant, Equipment, and Mine Development, Net
Property and equipment, gross	476		119
Construction in progress and other
Plant, Equipment, and Mine Development, Net
Property and equipment, gross	22,062		$ 20,619
Plant, equipment and mine development
Plant, Equipment, and Mine Development, Net
Depreciation and amortization	$ 2,100	$ 800
Minimum \| Process equipment
Plant, Equipment, and Mine Development, Net
Depreciation Life	5 years
Minimum \| Mine equipment
Plant, Equipment, and Mine Development, Net
Depreciation Life	5 years
Minimum \| Vehicles
Plant, Equipment, and Mine Development, Net
Depreciation Life	3 years
Maximum \| Process equipment
Plant, Equipment, and Mine Development, Net
Depreciation Life	13 years
Maximum \| Mine equipment
Plant, Equipment, and Mine Development, Net
Depreciation Life	7 years
Maximum \| Vehicles
Plant, Equipment, and Mine Development, Net
Depreciation Life	5 years