Organization	9 Months Ended
Sep. 30, 2014
Accounting Policies [Abstract]
Organization	(1) Organization Idera Pharmaceuticals, Inc. (“Idera” or the “Company”) is a clinical-stage biopharmaceutical company focused on the discovery, development and commercialization of novel therapeutics for rare diseases. The Company’s lead drug candidate is IMO-8400, a novel synthetic oligonucleotide antagonist of TLR7, TLR8 and TLR9. IMO-8400 is in development for the treatment of certain genetically defined forms of B-cell lymphoma and for the treatment of selected rare autoimmune diseases. The Company previously completed a Phase 1 clinical trial of IMO-8400 in healthy subjects and a Phase 2 proof-of-concept clinical trial in patients with moderate to severe plaque psoriasis. Idera is currently conducting a Phase 1/2 clinical trial of IMO-8400 in patients with Waldenström’s macroglobulinemia and Phase 1/2 clinical trial of IMO-8400 in patients with diffuse large B-cell lymphoma (“DLBCL”), who harbor the MYD88 L265P oncogenic mutation. The Company is also evaluating the potential application of TLR antagonism in rare diseases such as dermatomyositis, a rare debilitating autoimmune disease, as well as Duchenne muscular dystrophy (“DMD”) and potentially other indications. The Company believes it can develop and commercialize therapies on its own in these disease indications, which are characterized by small, well-defined patient populations with serious unmet medical needs. The Company is also advancing a second novel synthetic oligonucleotide antagonist of TLR7, TLR8 and TLR 9, IMO-9200, as a drug candidate for potential use in selected autoimmune disease indications. The Company initiated patient dosing in a Phase 1 clinical trial of IMO-9200 in healthy volunteers in October 2014 and plans to select a lead indication for further development of this drug candidate in the first half of 2015. Idera is also developing gene silencing oligonucleotides (“GSOs”), a third generation antisense technology designed to inhibit the production of disease-associated proteins. The Company believes this technology may offer significant advantages over other currently practiced antisense and RNA interference (“RNAi”) technologies. At September 30, 2014, the Company had an accumulated deficit of $439,608,000. The Company expects to incur substantial operating losses in future periods. The Company does not expect to generate significant product revenue, sales-based milestones or royalties until the Company successfully completes development and obtains marketing approval for drug candidates, either alone or in collaborations with third parties, which the Company expects will take a number of years. In order to commercialize its drug candidates, the Company needs to complete clinical development and comply with comprehensive regulatory requirements. The Company is subject to a number of risks and uncertainties similar to those of other companies of the same size within the biotechnology industry, such as uncertainty of clinical trial outcomes, uncertainty of additional funding, and history of operating losses.

(1) Organization

Idera Pharmaceuticals, Inc. (“Idera” or the “Company”) is a clinical-stage biopharmaceutical company focused on the discovery, development and commercialization of novel therapeutics for rare diseases. The Company’s lead drug candidate is IMO-8400, a novel synthetic oligonucleotide antagonist of TLR7, TLR8 and TLR9. IMO-8400 is in development for the treatment of certain genetically defined forms of B-cell lymphoma and for the treatment of selected rare autoimmune diseases. The Company previously completed a Phase 1 clinical trial of IMO-8400 in healthy subjects and a Phase 2 proof-of-concept clinical trial in patients with moderate to severe plaque psoriasis.

Idera is currently conducting a Phase 1/2 clinical trial of IMO-8400 in patients with Waldenström’s macroglobulinemia and Phase 1/2 clinical trial of IMO-8400 in patients with diffuse large B-cell lymphoma (“DLBCL”), who harbor the MYD88 L265P oncogenic mutation. The Company is also evaluating the potential application of TLR antagonism in rare diseases such as dermatomyositis, a rare debilitating autoimmune disease, as well as Duchenne muscular dystrophy (“DMD”) and potentially other indications. The Company believes it can develop and commercialize therapies on its own in these disease indications, which are characterized by small, well-defined patient populations with serious unmet medical needs.

The Company is also advancing a second novel synthetic oligonucleotide antagonist of TLR7, TLR8 and TLR 9, IMO-9200, as a drug candidate for potential use in selected autoimmune disease indications. The Company initiated patient dosing in a Phase 1 clinical trial of IMO-9200 in healthy volunteers in October 2014 and plans to select a lead indication for further development of this drug candidate in the first half of 2015. Idera is also developing gene silencing oligonucleotides (“GSOs”), a third generation antisense technology designed to inhibit the production of disease-associated proteins. The Company believes this technology may offer significant advantages over other currently practiced antisense and RNA interference (“RNAi”) technologies.

At September 30, 2014, the Company had an accumulated deficit of $439,608,000. The Company expects to incur substantial operating losses in future periods. The Company does not expect to generate significant product revenue, sales-based milestones or royalties until the Company successfully completes development and obtains marketing approval for drug candidates, either alone or in collaborations with third parties, which the Company expects will take a number of years. In order to commercialize its drug candidates, the Company needs to complete clinical development and comply with comprehensive regulatory requirements.

The Company is subject to a number of risks and uncertainties similar to those of other companies of the same size within the biotechnology industry, such as uncertainty of clinical trial outcomes, uncertainty of additional funding, and history of operating losses.