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Income Taxes (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2025
Income Taxes (Textual) [Abstract]        
Income taxes at a statutory rate 35.00% 35.00% 35.00%  
Cumulative loss period 3 years      
Deferred Tax Assets, Valuation Allowance $ 143,508 $ 33,295 $ 45,531  
Operating loss carryforwards 77,100      
Share-based Compensation        
Income Taxes (Textual) [Abstract]        
Operating loss carryforwards 12,600      
Depletion Deduction        
Income Taxes (Textual) [Abstract]        
Depletion deduction carryforward $ 30,300      
Scenario, Forecast        
Income Taxes (Textual) [Abstract]        
Operating loss carryforwards       $ 8,700