Assumptions used to compute fair value of Pillar warrants [Line Items]

No definition available.

Name:	idra_AssumptionsUsedToComputeFairValueOfPillarWarrantsLineItems
Namespace Prefix:	idra_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Fair value assumptions expected percentage of warrants to be exercised.

+ References

No definition available.

+ Details

Name:	idra_FairValueAssumptionsExpectedPercentageOfWarrantsToBeExercised
Namespace Prefix:	idra_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Exercise price per share or per unit of warrants or rights outstanding.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(i)(4))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

+ Details

Name:	us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Period the instrument, asset or liability is expected to be outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (bbb)
-URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258

+ Details

Name:	us-gaap_FairValueAssumptionsExpectedTerm
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Measure of dispersion, in percentage terms (for instance, the standard deviation or variance), for a given stock price.

+ References

+ Details

Name:	us-gaap_FairValueAssumptionsExpectedVolatilityRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Risk-free interest rate assumption used in valuing an instrument.

+ References

+ Details

Name:	us-gaap_FairValueAssumptionsRiskFreeInterestRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Price of a single share of a number of saleable stocks of a company.

+ References

No definition available.

+ Details

Name:	us-gaap_SharePrice
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_ClassOfWarrantOrRightAxis=idra_PillarOneWarrantsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ClassOfWarrantOrRightAxis=idra_AdditionalPillarWarrantsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

April 2013 Pillar Agreements - Schedule of Assumptions and Other Inputs Used to Compute Fair Value of Agreement Warrants (Details) - $ / shares	May 07, 2013	Apr. 30, 2013	Apr. 22, 2013
Pillar I Warrants
Assumptions used to compute fair value of Pillar warrants
Stock price (in dollars per share)	$ 0.57
Warrant exercise price per share	$ 0.61		$ 0.61
Term of warrant (years)	5 years
Expected volatility	62.00%
Average risk free interest rate	0.80%
Expected percentage of warrants to be exercised	100.00%
Additional Pillar Warrants
Assumptions used to compute fair value of Pillar warrants
Stock price (in dollars per share)	$ 0.57
Warrant exercise price per share	$ 0.79	$ 0.79
Term of warrant (years)	1 year 1 month 6 days
Expected volatility	67.00%
Average risk free interest rate	0.10%
Expected percentage of warrants to be exercised	100.00%