Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Operating Expenses:
Mineral property expenses	$ (4,584)	$ (3,248)
General and administrative	(6,614)	(7,650)
Acquisition related costs	(1,003)
Accretion of asset retirement obligations	(1,039)	(480)
Depreciation and amortization	(142)	(247)
Impairment of uranium properties	(11,436)	(1,673)
Total operating expenses	(24,818)	(13,298)
Non-Operating Income/(Expenses):
Loss on extinguishment of convertible debt	(39)	(3,322)
Interest income (expense)	614	(2,800)
Commitment fees		(333)
Gain on disposal/exchange of uranium properties	4,927
Other income/(expense), net	28	148
Total other income/(expense)	5,530	(6,307)
Net Loss	(19,288)	(19,605)
Other Comprehensive Loss
Unrealized fair value increase (decrease) on available-for-sale securities	287	(49)
Transfer to realized gain upon sale of available-for-sale securities		116
Comprehensive Loss	$ (19,001)	$ (19,538)
BASIC AND DILUTED LOSS PER SHARE	$ (0.78)	$ (3.73)
WEIGHTED AVERAGE NUMBER OF SHARES OUTSTANDING	24,736,955	5,251,954