The company is eligible to receive non refundable fee upon exercise of option.

No definition available.

Name:	idra_CollaborativeArrangementNonRefundableFeeUponExerciseOfOption
Namespace Prefix:	idra_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The percentage of outstanding common stock acquired under the collaborative agreement.

+ References

No definition available.

+ Details

Name:	idra_CollaborativeArrangementPercentageOfOutstandingCommonStockAcquired
Namespace Prefix:	idra_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of transaction price of the contract under the collaborative arrangement.

+ References

No definition available.

+ Details

Name:	idra_CollaborativeArrangementTransactionPrice
Namespace Prefix:	idra_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Deferred revenue, amortization period

+ References

No definition available.

+ Details

Name:	idra_DeferredRevenueAmortizationPeriod
Namespace Prefix:	idra_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of optional additional targets.

+ References

No definition available.

+ Details

Name:	idra_NumberOfAdditionalTargetOptional
Namespace Prefix:	idra_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of development candidates.

+ References

No definition available.

+ Details

Name:	idra_NumberOfDevelopmentCandidates
Namespace Prefix:	idra_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum royalty percentage on net sales.

+ References

No definition available.

+ Details

Name:	idra_PercentageOfMaximumRoyaltyOnNetSales
Namespace Prefix:	idra_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Milestone payments that may be received under collaboration agreements.

+ References

No definition available.

+ Details

Name:	idra_RevenueRecognitionMilestoneMethodMaximumMilestonePayments
Namespace Prefix:	idra_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The upfront, non-refundable, non-creditable cash payment received under the collaboration agreement.

+ References

No definition available.

+ Details

Name:	idra_UpfrontPaymentReceivedUnderCollaboration
Namespace Prefix:	idra_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of revenue recognized that was previously included in balance of obligation to transfer good or service to customer for which consideration from customer has been received or is due.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 8
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130549-203045

+ Details

Name:	us-gaap_ContractWithCustomerLiabilityRevenueRecognized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of investment in equity security without readily determinable fair value.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 321
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=116654751&loc=SL75117539-209714

+ Details

Name:	us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount, including tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value-added and excise.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130545-203045

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130543-203045

+ Details

Name:	us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of transaction price allocated to performance obligation that has not been recognized as revenue.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130556-203045

+ Details

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

- Details

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

- Details

Name:	us-gaap_BalanceSheetLocationAxis=us-gaap_OtherAssetsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	us-gaap_TypeOfArrangementAxis=idra_UpFrontPaymentsArrangementMember
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_CounterpartyNameAxis=idra_GskAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

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

- Details

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

- Details

Name:	idra_AccountingUnitsAxis=idra_IMO9200LicenseMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Collaboration and License Agreements (Details)	1 Months Ended			3 Months Ended		6 Months Ended
Collaboration and License Agreements (Details)	Apr. 30, 2019 USD ($)	Nov. 30, 2016 USD ($)	Nov. 30, 2015 USD ($) person	Jun. 30, 2019 USD ($)	Jun. 30, 2018 USD ($)	Jun. 30, 2019 USD ($)	Jun. 30, 2018 USD ($)
Collaborative Arrangements and Non-collaborative Arrangement Transactions
Alliance revenue				$ 1,448,000	$ 163,000	$ 1,448,000	$ 418,000
Option and License Agreement with Licensee
Collaborative Arrangements and Non-collaborative Arrangement Transactions
Alliance revenue				1,400,000		1,400,000
Transaction price						1,400,000
Performance obligation				0		$ 0
Percentage of shares acquired	10.00%					10.00%
Option and License Agreement with Licensee \| Other Assets
Collaborative Arrangements and Non-collaborative Arrangement Transactions
Equity Securities without Readily Determinable Fair Value, Amount				100,000		$ 100,000
Vivelix
Collaborative Arrangements and Non-collaborative Arrangement Transactions
Alliance revenue				0		0
Vivelix \| Up-front Payment Arrangement
Collaborative Arrangements and Non-collaborative Arrangement Transactions
Upfront payment received under collaboration agreement		$ 15,000,000
Vivelix \| Maximum
Collaborative Arrangements and Non-collaborative Arrangement Transactions
Alliance revenue					100,000		100,000
GSK Agreement
Collaborative Arrangements and Non-collaborative Arrangement Transactions
Number of development candidates \| person			1
Number of optional additional targets \| person			2
Deferred revenue recognized during the period				$ 0	$ 100,000	$ 0	$ 300,000
Research period			2 years			36 months
GSK Agreement \| Up-front Payment Arrangement
Collaborative Arrangements and Non-collaborative Arrangement Transactions
Upfront payment received under collaboration agreement			$ 2,500,000
GSK Agreement \| License, Research, Clinical Development and Commercialization
Collaborative Arrangements and Non-collaborative Arrangement Transactions
Milestone payments						$ 18,000,000
GSK Agreement \| Research and Development Plans and Designation of Development Candidates
Collaborative Arrangements and Non-collaborative Arrangement Transactions
Milestone payments						1,000,000
GSK Agreement \| Clinical and Commercial Milestones
Collaborative Arrangements and Non-collaborative Arrangement Transactions
Milestone payments						$ 17,000,000
GSK Agreement \| Maximum
Collaborative Arrangements and Non-collaborative Arrangement Transactions
Maximum royalty percentage on net sales						5.00%
IMO-9200 License \| Option and License Agreement with Licensee
Collaborative Arrangements and Non-collaborative Arrangement Transactions
Upfront payment received under collaboration agreement	$ 1,400,000
Non-refundable fee upon exercise of option	$ 1,000,000