v3.10.0.1
COMMITMENTS AND CONTINGENCIES - Surety, Reclamation Bonds and Flow-Through Common Shares (Details)
$ in Thousands, $ in Millions
6 Months Ended 12 Months Ended
Dec. 19, 2017
USD ($)
Sep. 22, 2017
USD ($)
Aug. 25, 2017
USD ($)
Jul. 01, 2017
USD ($)
Jun. 23, 2017
USD ($)
Jun. 30, 2018
CAD ($)
Jun. 30, 2018
USD ($)
Dec. 31, 2017
CAD ($)
Dec. 31, 2017
USD ($)
Reclamation Bonds                  
Other assets             $ 9,707   $ 10,718
Amount raised or spent in connection with the equity issuance   $ 43,200         39,400    
Surety Bonds                  
Reclamation Bonds                  
Face amount         $ 20,000        
Percentage of annual fees on surety bonds         2.00%        
Percentage of upfront deposit on surety bonds         0.00%        
Surety bonds upfront deposit amount     $ 15,000            
Surety Bonds | Tonkin Project                  
Reclamation Bonds                  
Surety bond draw down       $ 3,600          
Surety Bonds | Nevada Exploration Properties                  
Reclamation Bonds                  
Surety bond draw down       $ 1,300          
Surety Bonds | Gold Bar project                  
Reclamation Bonds                  
Surety bond draw down     $ 15,000            
Reclamation Bonds                  
Reclamation Bonds                  
Reclamation bonding obligation             $ 19,900    
Black Fox                  
Reclamation Bonds                  
Percentage of upfront deposit on surety bonds           2.00% 2.00%    
Surety bonds upfront deposit amount             $ 0    
Surety bonding obligation           $ 20.6 15,700    
Outstanding surety bonds             20,000    
Timmins                  
Reclamation Bonds                  
Surety bonds upfront deposit amount             100    
Flow Through Common Shares                  
Reclamation Bonds                  
Amount raised or spent in connection with the equity issuance $ 10,000           6,400 $ 12.9 $ 10,000
Total costs incurred for Canadian Exploration Expenditures             $ 8,000