Annual report pursuant to Section 13 and 15(d)

Asset Retirement and Reclamation Obligations - rollforward (Details)

v2.4.1.9
Asset Retirement and Reclamation Obligations - rollforward (Details) (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Asset Retirement Obligation Rollforward    
Beginning of year $ 17,279us-gaap_AssetRetirementObligation $ 957us-gaap_AssetRetirementObligation
Liabilities incurred   10,639us-gaap_AssetRetirementObligationLiabilitiesIncurred
Assumed in Pathfinder Mining Corporation purchase   5,656urg_AssetRetirementObligationLiabilitiesAssumed
Change in estimated liability 5,669us-gaap_AssetRetirementObligationRevisionOfEstimate  
Accretion expense 497us-gaap_AssetRetirementObligationAccretionExpense 27us-gaap_AssetRetirementObligationAccretionExpense
End of period $ 23,445us-gaap_AssetRetirementObligation $ 17,279us-gaap_AssetRetirementObligation