Quarterly report pursuant to Section 13 or 15(d)

Mineral Properties (Details)

v3.19.2
Mineral Properties (Details) - USD ($)
$ in Thousands
1 Months Ended 3 Months Ended 6 Months Ended 12 Months Ended
Dec. 31, 2013
Jun. 30, 2019
Jun. 30, 2018
Jun. 30, 2019
Jun. 30, 2018
Dec. 31, 2005
Aggregate consideration $ 6,700          
Revenue, Net, Total   $ 11,479 $ 3,807 $ 16,291 $ 23,479  
Estimated asset reclamation obligation $ 5,700          
Nfu Wyoming LLC            
Percentage of asset acquired           100.00%
Aggregate consideration           $ 20,000