Name:	idra_MaximumPercentageDefinedAnnualizedBasePayUsedToBuyStockUnderEmployeeStockPurchasePlan
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Data Type:	num:percentItemType
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Period Type:	duration

Maximum percentage in payroll of deduction base salary to acquire shares of common stock under the ESSP plan.

No definition available.

Name:	idra_MaximumPercentageInPayrollOfDeductionBaseSalaryToAcquireSharesOfCommonStock
Namespace Prefix:	idra_
Data Type:	num:percentItemType
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Period Type:	duration

Minimum percentage in payroll of deduction base salary to acquire shares of common stock under the ESSP plan.

No definition available.

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

The maximum percentage of total combined voting power or value of the stock of the Company after the grant.

No definition available.

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

The percentage of fair market value of common stock for the ESPP option price.

No definition available.

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

Percentage of market value of common stock on the commencement of offering period.

No definition available.

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

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.

No definition available.

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

The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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

Number of share instruments newly issued under a share-based compensation plan.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901