Annual report pursuant to Section 13 and 15(d)

Shareholders' Equity and Capital Stock - o/s RSUs (Details)

v2.4.1.9
Shareholders' Equity and Capital Stock - o/s RSUs (Details) (USD $)
In Thousands, except Share data, unless otherwise specified
 12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
RSUs        
Number of unvested units 379,435us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber 691,610us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber 826,425us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber 276,365us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber
Remaining life (years) 1 year 5 months 23 days      
Aggregate Intrinsic Value $ 322us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue      
Grant Date One [Member]        
RSUs        
Grant date Dec. 27, 2013      
Number of unvested units 120,243us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber
/ urg_GrandDateAxis
= urg_GrantDateOneMember 		     
Remaining life (years) 11 months 23 days      
Aggregate Intrinsic Value 102us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue
/ urg_GrandDateAxis
= urg_GrantDateOneMember 		     
Grant Date Two [Member]        
RSUs        
Grant date Dec. 12, 2014      
Number of unvested units 259,192us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber
/ urg_GrandDateAxis
= urg_GrantDateTwoMember 		     
Remaining life (years) 1 year 11 months 9 days      
Aggregate Intrinsic Value $ 220us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue
/ urg_GrandDateAxis
= urg_GrantDateTwoMember