Leases - Schedule of Undiscounted Cash Flows to be Received Under Operating Sublease on an Annual Basis (Details) $ in Thousands	Mar. 31, 2020 USD ($)
Leases [Abstract]
Remainder of 2020	$ 61
2021	235
2022	243
2023	251
2024	49
Lessee operating sublease payments to be received	$ 839

Lessee operating sub lease payments to be received.

No definition available.

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

Lessee operating sub lease payments to be received five years.

No definition available.

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

Lessee operating sub lease payments to be received four years.

No definition available.

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

Lessee operating sub lease payments to be received remainder of fiscal year.

No definition available.

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

Lessee operating sub lease payments to be received three years.

No definition available.

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

Lessee operating sub lease payments to be received two years.

No definition available.

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

No definition available.