Annual report pursuant to Section 13 and 15(d)

Document and Entity Information

v3.21.1
Document and Entity Information - USD ($)
 12 Months Ended
Dec. 31, 2020
Apr. 12, 2021
Jun. 30, 2020
Cover [Abstract]      
Entity Registrant Name GT Biopharma, Inc.    
Document Type 10-K    
Document Period End Date Dec. 31, 2020    
Amendment Flag false    
Entity Central Index Key 0000109657    
Is Entity a Well-known Seasoned Issuer? No    
Is Entity a Voluntary Filer? No    
Is Entity's Reporting Status Current? No    
Entity Filer Category Non-accelerated Filer    
Entity Emerging Growth Company false    
Entity Small Business true    
Entity Shell Company false    
Entity Interactive Data Current Yes    
Entity Incorporation, State or Country Code DE    
Entity File Number 000-08092    
Entity Public Float     $ 8,900,000
Entity Common Stock, Shares Outstanding   28,393,960  
Document Fiscal Period Focus FY    
Document Fiscal Year Focus 2020    
Current Fiscal Year End Date --12-31