Property and Equipment - Additional Information (Details) - USD ($)	3 Months Ended
Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Property and Equipment
Depreciation and amortization expense on property and equipment	$ 176,000	$ 176,000
Accrued Liabilities, Current	4,369,000		$ 7,394,000
Non-cash property additions	$ 33,000	$ 99,000

Property, plant and equipment additions for which the payment of the purchase price of the addition was not made as of the end of the reporting period.

No definition available.

+ Details

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

- Definition

Carrying value as of the balance sheet date of obligations incurred and payable, pertaining to costs that are statutory in nature, are incurred on contractual obligations, or accumulate over time and for which invoices have not yet been received or will not be rendered. Examples include taxes, interest, rent and utilities. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.20)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The aggregate expense recognized in the current period that allocates the cost of tangible assets, intangible assets, or depleting assets to periods that benefit from use of the assets.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3602-108585

+ Details

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Balance Type:	debit
Period Type:	duration

- References

No definition available.

+ Details

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Balance Type:	na
Period Type:	duration