Document and Entity Information - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2015
Mar. 15, 2016
Jun. 30, 2015
Document and Entity Information [Abstract]      
Entity Registrant Name Onconova Therapeutics, Inc.    
Entity Central Index Key 0001130598    
Document Type 10-K    
Document Period End Date Dec. 31, 2015    
Amendment Flag false    
Current Fiscal Year End Date --12-31    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Filer Category Smaller Reporting Company    
Entity Public Float     $ 30.1
Entity Common Stock, Shares Outstanding   27,401,035  
Document Fiscal Year Focus 2015    
Document Fiscal Period Focus FY