v3.7.0.1
Document And Entity Information - shares
6 Months Ended
Jun. 30, 2017
Aug. 04, 2017
Document Information [Line Items]    
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Jun. 30, 2017  
Document Fiscal Year Focus 2017  
Document Fiscal Period Focus Q2  
Entity Registrant Name ENZON PHARMACEUTICALS, INC.  
Entity Central Index Key 0000727510  
Current Fiscal Year End Date --12-31  
Entity Filer Category Smaller Reporting Company  
Trading Symbol ENZN  
Entity Common Stock, Shares Outstanding   44,214,603