Ur-Energy Inc. Annual report pursuant to Section 13 and 15(d)

Annual report pursuant to Section 13 and 15(d)

Shareholders' Equity and Capital Stock - addl information (Details)

Shareholders' Equity and Capital Stock - addl information (Details) $ / shares in Units, $ in Thousands		1 Months Ended		8 Months Ended	12 Months Ended
	May 27, 2016 USD ($)	Jan. 31, 2016 shares	Jan. 31, 2015 shares	Dec. 31, 2017 CAD / shares	Dec. 31, 2017 USD ($) item shares	Dec. 31, 2016 USD ($) shares	Dec. 31, 2015 USD ($) $ / shares shares	Dec. 31, 2017 USD ($) $ / shares shares	Dec. 31, 2016 CAD / shares shares	Dec. 31, 2016 $ / shares shares	Dec. 31, 2014 $ / shares shares
Stockholder's Equity Note [Line Items]
Share-Based Compensation Arrangement By Share-Based Payment Award, Options, Outstanding, Intrinsic Value \| $								$ 354
Common Stock Shares Issued In Exchange Of Restricted Shares Units		197,374	197,374		447,663	385,010	215,168
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period					871,717	16,620	608,531
Stock Issued During Period, Shares, New Issues					1,536,169
Share Price \| (per share)				CAD 0.86				$ 0.76
Payments Of Stock Issuance Costs \| $					$ 93	$ 884
Proceeds from Issuance of Private Placement \| $	$ 10,000
Stock Issued During Period, Value, New Issues \| $					$ 1,076	$ 5,684
Threshold of combined service and age \| item					65
Percent or RSUs that vest					575,818	281,342	286,223
Minimum Service For RSU Plan					5 years
Share Based Compensation Arrangement By Share Based Payment Award Award Vesting Percentage					10.00%
Share-Based Compensation Arrangement By Share-Based Payment Award, Options, Outstanding, Number							9,974,407	9,459,401	9,748,934	9,748,934	8,468,614
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number								5,695,657
Stock based compensation \| $					$ 891	$ 857	$ 893
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested in Period, Fair Value \| $					700
Proceeds from Stock Options Exercised \| $					$ 542	$ 9	$ 410
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period					541,658	715,638	795,592
Granted, Options					2,666,644	3,062,542	2,384,052
RSUs vested but not redeemed (in shares)									8,374	8,374
Class of Warrant or Right, Exercise Price of Warrants or Rights \| $ / shares							$ 1.71	$ 0.97		$ 1.02	$ 1.20
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Exercise Price \| CAD / shares				0.90					CAD 0.73
Capital Stock
Stockholder's Equity Note [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period					871,717	16,620	608,531
Stock Issued During Period, Shares, New Issues					1,536,169	13,085,979
Stock Issued During Period, Value, New Issues \| $					$ 1,076	$ 5,684
In Money Stock Option [Member]
Stockholder's Equity Note [Line Items]
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Stock Options \| $								$ 1,100
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Period for Recognition					2 years 3 months 18 days
Restricted Stock Units (RSUs) [Member]
Stockholder's Equity Note [Line Items]
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Share-based Awards Other than Options \| $								$ 600
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Period for Recognition					1 year 4 months 24 days
RSUs vested but not redeemed (in shares)							212,803
RSUs redeemed against tax effect (in shares)							15,429
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Exercise Price \| CAD / shares				CAD 0.73
Restricted Stock Units (RSUs) [Member] \| Capital Stock
Stockholder's Equity Note [Line Items]
Number of securities called by each unit								1
Four and One Half Months After Grant [Member]
Stockholder's Equity Note [Line Items]
Share Based Compensation Arrangement By Share Based Payment Award Award Vesting Percentage					22.00%
Nine Months After Grant [Member]
Stockholder's Equity Note [Line Items]
Share Based Compensation Arrangement By Share Based Payment Award Award Vesting Percentage					22.00%
Thirteen and One Half Months After Grant [Member]
Stockholder's Equity Note [Line Items]
Share Based Compensation Arrangement By Share Based Payment Award Award Vesting Percentage					22.00%
Eighteen Months After Date Of Grant [Member]
Stockholder's Equity Note [Line Items]
Share Based Compensation Arrangement By Share Based Payment Award Award Vesting Percentage					24.00%
First Anniversary [Member]
Stockholder's Equity Note [Line Items]
Share-Based Compensation Arrangement By Share-Based Payment Award, Award Vesting Percentage				33.30%
Second Anniversary [Member]
Stockholder's Equity Note [Line Items]
Share-Based Compensation Arrangement By Share-Based Payment Award, Award Vesting Percentage				33.30%
Percent or RSUs that vest					100
Third Anniversary (Member)
Stockholder's Equity Note [Line Items]
Share-Based Compensation Arrangement By Share-Based Payment Award, Award Vesting Percentage				33.40%
Maximum \| Restricted Stock Units (RSUs) [Member]
Stockholder's Equity Note [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Exercise Price \| CAD / shares									1.22
Minimum \| Restricted Stock Units (RSUs) [Member]
Stockholder's Equity Note [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Exercise Price \| CAD / shares									CAD 0.80