Quarterly report pursuant to Section 13 or 15(d)

Commitments (Details Textual)

v2.4.0.8
Commitments (Details Textual) (USD $)
In Millions, unless otherwise specified
6 Months Ended
Jun. 30, 2014
Commitments And Contingencies Disclosure [Line Items]  
Increase In Reclamation Amount $ 26.7
Increase In Security Bonds 3.1
True Drilling LLC [Member]
 
Commitments And Contingencies Disclosure [Line Items]  
Contractual Obligation Paid Amount $ 3.2