The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iii)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

+ References

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of options outstanding, including both vested and non-vested options.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(i)-(ii)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(i)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_PlanNameAxis=URRE_TwoThousandFourStockOptionPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PlanNameAxis=URRE_TwoThousandFourDirectorsPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PlanNameAxis=URRE_TwoThousandThirteenStockOptionPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PlanNameAxis=URRE_ReplacementStockOptionsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Stock-Based Compensation - Summary of Stock Options Outstanding and Exercisable by Stock Option Plan (Details) - $ / shares	Jun. 30, 2016	Dec. 31, 2015	Jun. 30, 2015	Dec. 31, 2014
Outstanding Stock Options, Number of Options Outstanding	321,700	326,424	13,188	13,396
Outstanding Stock Options, Weighted Average Exercise Price	$ 18.82	$ 24.90	$ 300.72	$ 303.36
Exercisable Stock Options Exercisable, Number of Options Exercisable	321,491		11,139
Exercisable Stock Options Exercisable, Weighted Average Exercise Price	$ 18.81		$ 349.56
2004 Plan [Member]
Outstanding Stock Options, Number of Options Outstanding	5,792
Outstanding Stock Options, Weighted Average Exercise Price	$ 121.17
Exercisable Stock Options Exercisable, Number of Options Exercisable	5,792
Exercisable Stock Options Exercisable, Weighted Average Exercise Price	$ 121.17
2004 Director's Plan [Member]
Outstanding Stock Options, Number of Options Outstanding	1,390
Outstanding Stock Options, Weighted Average Exercise Price	$ 629.52
Exercisable Stock Options Exercisable, Number of Options Exercisable	1,390
Exercisable Stock Options Exercisable, Weighted Average Exercise Price	$ 629.52
2013 Plan [Member]
Outstanding Stock Options, Number of Options Outstanding	417
Outstanding Stock Options, Weighted Average Exercise Price	$ 35.88
Exercisable Stock Options Exercisable, Number of Options Exercisable	208
Exercisable Stock Options Exercisable, Weighted Average Exercise Price	$ 35.88
Replacement Stock Options [Member]
Outstanding Stock Options, Number of Options Outstanding	314,101
Outstanding Stock Options, Weighted Average Exercise Price	$ 14.21
Exercisable Stock Options Exercisable, Number of Options Exercisable	314,101
Exercisable Stock Options Exercisable, Weighted Average Exercise Price	$ 14.21