Quarterly report pursuant to Section 13 or 15(d)

Mineral Properties - rollforward (Details)

v3.19.2
Mineral Properties - rollforward (Details) - USD ($)
$ in Thousands
 6 Months Ended 12 Months Ended
Jun. 30, 2019
Dec. 31, 2018
Balance at beginning of period $ 45,805  
Acquisition costs 8  
Change in estimated reclamation costs (Note 13)   $ 2,840
Amortization (1,301)  
Balance at end of period 44,512 45,805
Lost Creek Project    
Balance at beginning of period 12,644  
Amortization (1,301)  
Balance at end of period 11,343 12,644
Pathfinder properties    
Balance at beginning of period 19,964  
Balance at end of period 19,964 19,964
Other U.S. Properties [Member]    
Balance at beginning of period 13,197  
Acquisition costs 8  
Balance at end of period $ 13,205 $ 13,197