Annual report pursuant to Section 13 and 15(d)

Asset Retirement and Reclamation Obligations (Details)

v2.4.1.9
Asset Retirement and Reclamation Obligations (Details) (USD $)
 12 Months Ended
Dec. 31, 2014
Change in estimated liability $ 5,669,000us-gaap_AssetRetirementObligationRevisionOfEstimate
Lost Creek Property  
Estimated Future Cash Undiscounted Amount 12,100,000urg_EstimatedFutureCashUndiscountedAmount
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= urg_LostCreekPropertyMember
Change in estimated liability 0us-gaap_AssetRetirementObligationRevisionOfEstimate
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= urg_LostCreekPropertyMember
Lost Creek Property | Minimum  
Discount Rate Of Asset Retirement Obligations 0.30%urg_DiscountRateOfAssetRetirementObligations
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= urg_LostCreekPropertyMember
Lost Creek Property | Maximum  
Discount Rate Of Asset Retirement Obligations 3.30%urg_DiscountRateOfAssetRetirementObligations
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= urg_LostCreekPropertyMember
Path Finder Mines [Member]  
Estimated Future Cash Undiscounted Amount $ 12,700,000urg_EstimatedFutureCashUndiscountedAmount
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= urg_PathFinderMinesMember
Discount Rate Of Asset Retirement Obligations 3.00%urg_DiscountRateOfAssetRetirementObligations
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= urg_PathFinderMinesMember