v3.19.3
Cover Page - shares
9 Months Ended
Sep. 30, 2019
Oct. 31, 2019
Cover [Abstract]    
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Sep. 30, 2019  
Document Fiscal Year Focus 2019  
Document Fiscal Period Focus Q3  
Entity Registrant Name ZIOPHARM ONCOLOGY INC  
Entity Central Index Key 0001107421  
Current Fiscal Year End Date --12-31  
Entity Filer Category Accelerated Filer  
Trading Symbol ZIOP  
Entity Emerging Growth Company false  
Entity Small Business true  
Entity Common Stock, Shares Outstanding   181,030,020
Entity Interactive Data Current Yes  
Title of 12(b) Security Common Stock  
Security Exchange Name NASDAQ  
Entity Current Reporting Status Yes  
Entity Shell Company false  
Entity Address, State or Province MA