Contract with customer additional milestone payment eligible to receive.

No definition available.

Name:	urgn_ContractWithCustomerAdditionalMilestonePaymentEligibleToReceive
Namespace Prefix:	urgn_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

License agreement expiration term.

+ References

No definition available.

+ Details

Name:	urgn_LicenseAgreementExpirationTerm
Namespace Prefix:	urgn_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum amount payable upon achieving certain clinical development and regulatory milestones.

+ References

No definition available.

+ Details

Name:	urgn_MaximumAmountPayableUponAchievingCertainClinicalDevelopmentAndRegulatoryMilestones
Namespace Prefix:	urgn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Maximum amount payable upon achieving certain commercial milestones.

+ References

No definition available.

+ Details

Name:	urgn_MaximumAmountPayableUponAchievingCertainCommercialMilestones
Namespace Prefix:	urgn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Milestone payment received for licensing agreement.

+ References

No definition available.

+ Details

Name:	urgn_MilestonePaymentsReceivedForLicensingAgreement
Namespace Prefix:	urgn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Royalty ranging on net sales of licensed products.

+ References

No definition available.

+ Details

Name:	urgn_RoyaltyRangingOnNetSalesOfLicensedProducts
Namespace Prefix:	urgn_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Upfront fee.

+ References

No definition available.

+ Details

Name:	urgn_UpfrontFee
Namespace Prefix:	urgn_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The amount of costs incurred under a research and development arrangement accounted for as a contract to perform research and development for others.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 730
-SubTopic 20
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=6420387&loc=d3e23221-108380

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 730
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6420387&loc=d3e23199-108380

+ Details

Name:	us-gaap_ResearchAndDevelopmentArrangementContractToPerformForOthersCostsIncurredGross
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_ResearchAndDevelopmentArrangementContractToPerformForOthersLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_ResearchAndDevelopmentArrangementContractToPerformForOthersByTypeAxis=us-gaap_LicenseAgreementTermsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementScenarioAxis=urgn_AfterFirstCommercialSaleOfLicensedProductMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ResearchAndDevelopmentArrangementContractToPerformForOthersByTypeAxis=urgn_MDAndersonMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_CounterpartyNameAxis=urgn_AllerganPharmaceuticalsInternationalLimitedAndAbbVieIncMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_TypeOfArrangementAxis=urgn_LicenseAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

License and Collaboration Agreements - Additional Information (Details) - USD ($)	1 Months Ended	3 Months Ended
	Nov. 30, 2019	Mar. 31, 2021
Agenus Agreement
Research And Development Arrangement Contract To Perform For Others [Line Items]
Upfront fee	$ 10,000,000.0
Maximum amount payable upon achieving certain clinical development and regulatory milestones	115,000,000.0
Maximum amount payable upon achieving certain commercial milestones	$ 85,000,000.0
Agenus Agreement \| After First Commercial Sale of Licensed Product
Research And Development Arrangement Contract To Perform For Others [Line Items]
License agreement expiration term	15 years
MD Anderson
Research And Development Arrangement Contract To Perform For Others [Line Items]
Payments recognized through research and development expenses		$ 500,000
Maximum \| Agenus Agreement
Research And Development Arrangement Contract To Perform For Others [Line Items]
Royalty ranging on net sales of licensed products	20.00%
Minimum \| Agenus Agreement
Research And Development Arrangement Contract To Perform For Others [Line Items]
Royalty ranging on net sales of licensed products	14.00%
Allergan/AbbVie \| License Agreement
Research And Development Arrangement Contract To Perform For Others [Line Items]
Milestone payments received for licensing agreement		25,000,000.0
Allergan/AbbVie \| License Agreement \| Maximum
Research And Development Arrangement Contract To Perform For Others [Line Items]
License agreement additional milestone payments eligible to receive		$ 200,000,000.0