Annual report pursuant to Section 13 and 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

Subsequent Events - Additional Information (Details)

v3.20.1

Subsequent Events - Additional Information (Details) - Subsequent Event	Jan. 21, 2020 USD ($) Debtinstrument shares
Iterum Therapeutics Bermuda Limited
Subsequent Event [Line Items]
Ownership percentage	100.00%
Subsidiary Guarantors
Subsequent Event [Line Items]
Ownership percentage	100.00%
Private Placement \| Exchangeable Notes
Subsequent Event [Line Items]
Aggregate principal amount	$ 51,600,000
Debt instrument price per unit	1,000
Private Placement \| RLNs
Subsequent Event [Line Items]
Aggregate principal amount	$ 100,000
Number of debt instruments within each notes \| Debtinstrument	50
Debt instrument, aggregate potential payment capped value	$ 160,000
Debt instrument, aggregate potential payment capped rate	4,000 times
Private Placement \| Securities
Subsequent Event [Line Items]
Debt instrument price per unit	$ 1,000
Debt instrument, shares embedded within each unit, shares \| shares	1,000
Debt instrument, shares embedded within each unit, value	$ 1,000
Proceeds from sale of securities	$ 46,700,000
Minimum \| Private Placement \| RLNs
Subsequent Event [Line Items]
Debt instrument, percentage of net revenue from domestic sale for potential aggregate payments	15.00%
Maximum \| Private Placement \| RLNs
Subsequent Event [Line Items]
Debt instrument, percentage of net revenue from domestic sale for potential aggregate payments	20.00%

- Definition

Debt instrument aggregate amount of payments on royalty linked subordinated.

+ References

No definition available.

+ Details

Name:	itrm_DebtInstrumentAggregateAmountOfPaymentsOnRoyaltyLinkedSubordinated
Namespace Prefix:	itrm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Debt instrument aggregate potential payment capped rate.

+ References

No definition available.

+ Details

Name:	itrm_DebtInstrumentAggregatePotentialPaymentCappedRate
Namespace Prefix:	itrm_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt instrument percentage of net revenue from domestic sale for potential aggregate payments.

+ References

No definition available.

+ Details

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Namespace Prefix:	itrm_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt instrument price per unit.

+ References

No definition available.

+ Details

Name:	itrm_DebtInstrumentPricePerUnit
Namespace Prefix:	itrm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Debt instrument shares embedded within each unit shares.

+ References

No definition available.

+ Details

Name:	itrm_DebtInstrumentSharesEmbeddedWithinEachUnitShares
Namespace Prefix:	itrm_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt instrument shares embedded within each unit value.

+ References

No definition available.

+ Details

Name:	itrm_DebtInstrumentSharesEmbeddedWithinEachUnitValue
Namespace Prefix:	itrm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Number of debt instruments within each unit.

+ References

No definition available.

+ Details

Name:	itrm_NumberOfDebtInstrumentsWithinEachUnit
Namespace Prefix:	itrm_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	duration

- Definition

Unit price per debt instrument.

+ References

No definition available.

+ Details

Name:	itrm_UnitPricePerDebtInstrument
Namespace Prefix:	itrm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
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+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The parent entity's interest in net assets of the subsidiary, expressed as a percentage.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of cash inflow from sale of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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+ Details

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

- Definition

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

+ References

No definition available.

+ Details

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Period Type:	duration

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Namespace Prefix:
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- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

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Namespace Prefix:
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Balance Type:
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- Details

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Namespace Prefix:
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Balance Type:
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- Details

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Namespace Prefix:
Data Type:	na
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- Details

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