Note 2 - Summary of Significant Accounting Policies (Details Textual) $ in Thousands		3 Months Ended				6 Months Ended		24 Months Ended	30 Months Ended
	May 29, 2020 USD ($)	Jun. 30, 2020 USD ($) oz	Mar. 31, 2020 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Jun. 30, 2020 USD ($) oz	Jun. 30, 2019 USD ($)	Dec. 31, 2016 shares	Jun. 30, 2020 USD ($) shares	Dec. 31, 2019 USD ($)
Reverse Recapitalization, Conversion Ratio	0.112
Net Income (Loss) Attributable to Parent, Total		$ (49,790)	$ (34,618)	$ (21,947)	$ (23,440)	$ (84,408)	$ (45,387)
Net Cash Provided by (Used in) Operating Activities, Total						(57,642)	(24,135)
Cash, Ending Balance	$ 68,900	47,293		12,576		47,293	12,576		$ 47,293	$ 6,220
Working Capital		68,000				68,000			68,000
Liabilities, Total		195,404				195,404			195,404	573,888
Retained Earnings (Accumulated Deficit), Ending Balance		$ (468,775)				$ (468,775)			(468,775)	(444,438)
Inventory, Ore on Leach Pads, Gold Ounces Written Off (Ounce) | oz		6,512				10,492
Cost of Goods and Services Sold, Total		$ 31,863		0		$ 55,731	0
Revenue from Contract with Customer, Excluding Assessed Tax, Total		7,636		$ 0		18,760	$ 0
Excess of Cost of Goods and Services Sold over Revenues		22,100
Cash Equivalents, at Carrying Value, Total		0				0			0	0
Restricted Cash, Total		39,631				39,631			39,631	42,747
Asset Impairment Charges, Total		0
Mineral Properties, Gross		0				$ 0			$ 0	$ 0
Non-Employee Director Phantom Stock Plan [Member]
Number of Shares of Common Stock Considered for Cash Payment of Grants Issued (in shares) | shares								1	1
Production Costs, Mine-site Period Costs, and Cash Portion of Production Inventory [Member]
Cost of Goods and Services Sold, Total		$ 29,700