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
	Sep. 25, 2018 $ / shares shares	May 27, 2016 USD ($)	Dec. 31, 2018 $ / shares shares	Sep. 30, 2018 USD ($) $ / shares shares	Mar. 31, 2018 shares	Jan. 31, 2016 shares	Jan. 31, 2015 shares	Dec. 31, 2017 $ / shares shares	Dec. 31, 2018 USD ($) item shares	Dec. 31, 2017 USD ($) shares	Dec. 31, 2016 USD ($) shares	Dec. 31, 2018 USD ($) $ / shares shares	Dec. 31, 2017 $ / shares shares	Dec. 31, 2016 $ / shares shares	Dec. 31, 2016 $ / shares shares	Dec. 31, 2015 $ / shares shares
Stockholder's Equity Note [Line Items]
Share-Based Compensation Arrangement By Share-Based Payment Award, Options, Outstanding, Intrinsic Value \| $												$ 323
Common Stock Shares Issued In Exchange Of Restricted Shares Units			32,000,000			197,374	197,374		505,510	447,663	385,010
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period									496,838	871,717	16,620
Stock Issued During Period, Shares, New Issues										1,536,169
Share Price \| (per share)	$ 0.82		$ 0.89										$ 0.76
Payments Of Stock Issuance Costs \| $									$ 902	$ 93	$ 884
Proceeds from Issuance of Private Placement \| $		$ 10,000		$ 10,000
Option period for underwriters				30 days
Option to purchase additional common shares by underwriters				1,829,268
Warrant to purchase additional common shares by underwriters				914,634
Additional warrants acquired by underwriters				867,756
Common shares purchased by acquiring additional warrants by underwriters				433,878
Number of RSUs Vested					62,000				621,092	575,818	281,342
Stock Issued During Period, Value, New Issues \| $									$ 7,399	$ 1,076	$ 5,684
Threshold of combined service and age \| item									65
Percent or RSUs that vest					62,000				621,092	575,818	281,342
Minimum Service For RSU Plan									5 years
Share-Based Compensation Arrangement By Share-Based Payment Award, Options, Outstanding, Number								9,459,401				9,731,612	9,459,401	9,748,934	9,748,934	9,974,407
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number												6,117,506
Stock based compensation \| $									$ 915	$ 891	$ 857
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested in Period, Fair Value \| $									800
Proceeds from Stock Options Exercised \| $									$ 290	$ 542	$ 9
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period									470,756	541,658	715,638
Granted, Options									2,182,955	2,666,644	3,062,542
RSUs vested but not redeemed (in shares)														8,374	8,374
Class of Warrant or Right, Exercise Price of Warrants or Rights \| $ / shares												$ 1.00	$ 0.97		$ 1.02	$ 1.71
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Exercise Price \| $ / shares								$ 0.90						$ 0.73
Capital Stock
Stockholder's Equity Note [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period									496,838	871,717	16,620
Stock Issued During Period, Shares, New Issues	12,195,122								12,195,122	1,536,169	13,085,979
Stock Issued During Period, Value, New Issues \| $									$ 7,399	$ 1,076	$ 5,684
Warrants
Stockholder's Equity Note [Line Items]
Number of securities called by each warrant				0.5
Class of Warrant or Right, Exercise Price of Warrants or Rights \| $ / shares				$ 1.00
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 \| $												$ 1,200
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Period for Recognition									2 years 4 months 24 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 \| $												$ 500
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Period for Recognition									1 year 6 months
RSUs vested but not redeemed (in shares)														212,803	212,803
RSUs redeemed against tax effect (in shares)											15,429
Restricted Stock Units (RSUs) [Member] \| Capital Stock
Stockholder's Equity Note [Line Items]
Number of securities called by each warrant												1
Employee Stock Option [Member]
Stockholder's Equity Note [Line Items]
Vesting period								3 years
Proceeds from Stock Options Exercised \| $									$ 400	$ 500	$ 100
First Anniversary [Member] \| Employee Stock Option [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]
Number of RSUs Vested									100
Percent or RSUs that vest									100
Second Anniversary [Member] \| Employee Stock Option [Member]
Stockholder's Equity Note [Line Items]
Share-Based Compensation Arrangement By Share-Based Payment Award, Award Vesting Percentage								33.30%
Third Anniversary (Member) \| Employee Stock Option [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 \| $ / shares			0.93
Minimum
Stockholder's Equity Note [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Exercise Price \| $ / shares			$ 0.91