Annual report pursuant to Section 13 and 15(d)

Mineral Properties (Details)

v2.4.1.9
Mineral Properties (Details) (USD $)
12 Months Ended 1 Months Ended 12 Months Ended 1 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Apr. 30, 2013
item
Jun. 30, 2013
Dec. 31, 2005
Dec. 31, 2013
Stock Issued During Period Value Issued For Royalty Interest   $ 763,000urg_StockIssuedDuringPeriodValueIssuedForRoyaltyInterest        
Write-off of mineral properties 483,000us-gaap_AssetImpairmentCharges 1,430,000us-gaap_AssetImpairmentCharges        
Lost Creek Property            
Royalty (as a percent)     1.67%urg_RoyaltyOnFutureProductionPercentage
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= urg_LostCreekPropertyMember
     
Number Of Mining Claims     20urg_NumberOfMiningClaims
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= urg_LostCreekPropertyMember
     
Stock Issued During Period Shares Issued For Royalty Interest     1,000,000urg_StockIssuedDuringPeriodSharesIssuedForRoyaltyInterest
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= urg_LostCreekPropertyMember
     
Stock Issued During Period Value Issued For Royalty Interest     763,000urg_StockIssuedDuringPeriodValueIssuedForRoyaltyInterest
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= urg_LostCreekPropertyMember
     
Mining Claims In LC North LC East or LC West            
Royalty (as a percent) 0.00%urg_RoyaltyOnFutureProductionPercentage
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= urg_MiningClaimsInLcNorthLcEastOrLcWestMember
         
South Granite Mountain Project            
Write-off of mineral properties       261,000us-gaap_AssetImpairmentCharges
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= urg_SouthGraniteMountainProjectMember
   
Mustang Project            
Write-off of mineral properties   1,168,000us-gaap_AssetImpairmentCharges
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= urg_MustangProjectMember
       
Nfu Wyoming LLC | Lost Creek Property            
Percentage of asset acquired         100.00%urg_MineralPropertiesAcquiredPercentage
/ us-gaap_BusinessAcquisitionAxis
= urg_NfuWyomingLlcMember
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= urg_LostCreekPropertyMember
 
Aggregate consideration         20,000,000us-gaap_PaymentsToAcquireBusinessesGross
/ us-gaap_BusinessAcquisitionAxis
= urg_NfuWyomingLlcMember
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= urg_LostCreekPropertyMember
 
Pathfinder Mines Corporation            
Aggregate consideration           6,700,000us-gaap_PaymentsToAcquireBusinessesGross
/ us-gaap_BusinessAcquisitionAxis
= urg_PathfinderMinesCorporationMember
Royalty (as a percent)   5.00%urg_RoyaltyOnFutureProductionPercentage
/ us-gaap_BusinessAcquisitionAxis
= urg_PathfinderMinesCorporationMember
      5.00%urg_RoyaltyOnFutureProductionPercentage
/ us-gaap_BusinessAcquisitionAxis
= urg_PathfinderMinesCorporationMember
Estimated asset reclamation obligation   5,700,000us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther
/ us-gaap_BusinessAcquisitionAxis
= urg_PathfinderMinesCorporationMember
      5,700,000us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther
/ us-gaap_BusinessAcquisitionAxis
= urg_PathfinderMinesCorporationMember
Deferred tax liabilities   3,300,000us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxLiabilitiesNoncurrent
/ us-gaap_BusinessAcquisitionAxis
= urg_PathfinderMinesCorporationMember
      3,300,000us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxLiabilitiesNoncurrent
/ us-gaap_BusinessAcquisitionAxis
= urg_PathfinderMinesCorporationMember
Mineral properties   $ 15,300,000us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment
/ us-gaap_BusinessAcquisitionAxis
= urg_PathfinderMinesCorporationMember
      $ 15,300,000us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment
/ us-gaap_BusinessAcquisitionAxis
= urg_PathfinderMinesCorporationMember