| Cover | Nov. 15, 2020 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Nov. 15, 2020 |
| Entity File Number | 001-33038 |
| Entity Registrant Name | ZIOPHARM Oncology, Inc. |
| Entity Central Index Key | 0001107421 |
| Entity Tax Identification Number | 84-1475642 |
| Entity Incorporation, State or Country Code | DE |
| Entity Address, Address Line One | One First Avenue |
| Entity Address, Address Line Two | Parris Building 34 |
| Entity Address, Address Line Three | Navy Yard Plaza |
| Entity Address, City or Town | Boston |
| Entity Address, State or Province | MA |
| Entity Address, Postal Zip Code | 02129 |
| City Area Code | (617) |
| Local Phone Number | 259-1970 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, par value $0.001 per share |
| Trading Symbol | ZIOP |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
| Entity Information, Former Legal or Registered Name | Not applicable |
