Description of Business	3 Months Ended
Jun. 30, 2011
Nature of Operations [Text Block]	(1) Description of Business Enzon Pharmaceuticals, Inc. and subsidiaries (Enzon or the Company) is a biotechnology company dedicated to the research and development of innovative therapeutics for cancer patients with high unmet medical needs. Operations are funded in part by the receipt of royalty revenues from licensing arrangements with other companies related to sales of products developed using the Company’s proprietary Customized PEGylation Linker Technology (Customized Linker Technology®) – primarily PEGINTRON, marketed by Merck & Co., Inc. The Company operates in one business segment. The Company’s Principal Executive Officer (chief operating decision maker) reviews the Company’s operating results on an aggregate basis and manages the Company’s operations as a single operating unit. The Company’s operations and assets reside almost exclusively in the United States. The Company’s pipeline drug development programs utilize two platforms – Customized Linker Technology and third-generation messenger ribonucleic acid (mRNA)-targeting agents utilizing the Locked Nucleic Acid (LNA) technology. The Company currently has four compounds in clinical development: PEG-SN38 and the Hypoxia-Inducible Factor-1α (HIF-1α), Survivin and Androgen Receptor (AR) messenger RNA (mRNA) antagonists. In addition, the Company has other novel LNA targets in various stages of preclinical research. On January 29, 2010, the Company sold its specialty pharmaceutical business, comprised principally of the Company’s products and contract manufacturing segments, for approximately $309 million in cash with the potential for subsequent milestone payments and royalties.

Description of Business

3 Months Ended

Jun. 30, 2011

(1) Description of Business

Enzon Pharmaceuticals, Inc. and subsidiaries (Enzon or the Company) is a biotechnology company dedicated to the research and development of innovative therapeutics for cancer patients with high unmet medical needs. Operations are funded in part by the receipt of royalty revenues from licensing arrangements with other companies related to sales of products developed using the Company’s proprietary Customized PEGylation Linker Technology (Customized Linker Technology®) – primarily PEGINTRON, marketed by Merck & Co., Inc. The Company operates in one business segment. The Company’s Principal Executive Officer (chief operating decision maker) reviews the Company’s operating results on an aggregate basis and manages the Company’s operations as a single operating unit. The Company’s operations and assets reside almost exclusively in the United States.

The Company’s pipeline drug development programs utilize two platforms – Customized Linker Technology and third-generation messenger ribonucleic acid (mRNA)-targeting agents utilizing the Locked Nucleic Acid (LNA) technology. The Company currently has four compounds in clinical development: PEG-SN38 and the Hypoxia-Inducible Factor-1α (HIF-1α), Survivin and Androgen Receptor (AR) messenger RNA (mRNA) antagonists. In addition, the Company has other novel LNA targets in various stages of preclinical research.

On January 29, 2010, the Company sold its specialty pharmaceutical business, comprised principally of the Company’s products and contract manufacturing segments, for approximately $309 million in cash with the potential for subsequent milestone payments and royalties.