Quarterly report pursuant to Section 13 or 15(d)

Cover
- Document and Entity Information
Financial Statements
Notes to Financial Statements
Accounting Policies
- Summary of Significant Accounting Policies (Policies)
Notes Tables
Notes Details

Share-Based Compensation - Summary of Number of RSUs Granted (Details)

v3.23.1

Share-Based Compensation - Summary of Number of RSUs Granted (Details) - Restricted Share Units (RSUs)	3 Months Ended
	Mar. 31, 2023 shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Shares, RSUs outstanding Beginning Balance	128,728
Number of Shares, Shares vested	(39,289)
Number of Shares, RSUs outstanding Ending Balance	89,439
2015 Plan and 2018 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Shares, RSUs outstanding Beginning Balance	103,729
Number of Shares, Shares vested	(39,289)
Number of Shares, RSUs outstanding Ending Balance	64,440
Two Thousand Twenty One Inducement Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Shares, RSUs outstanding Beginning Balance	24,999
Number of Shares, RSUs outstanding Ending Balance	24,999
2015 Plan, 2018 Plan and 2021 Inducement Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Shares, RSUs outstanding Beginning Balance	128,728
Number of Shares, Shares vested	(39,289)
Number of Shares, RSUs outstanding Ending Balance	89,439

- Definition

The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(ii)
-URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(i)
-URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901

+ Details

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

- Definition

The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.

+ References

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
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_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_AwardTypeAxis=us-gaap_RestrictedStockUnitsRSUMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

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

- Details

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