Annual report pursuant to Section 13 and 15(d)

Cover Page

Cover Page - USD ($)
12 Months Ended
Dec. 31, 2019
Mar. 02, 2020
Jun. 30, 2019
Cover page.      
Document Type 10-K    
Document Annual Report true    
Document Period End Date Dec. 31, 2019    
Document Transition Report false    
Entity File Number 001-33304    
Entity Registrant Name FINJAN HOLDINGS, INC.    
Entity Incorporation, State or Country Code DE    
Entity Tax Identification Number 20-4075963    
Entity Address, Address Line One 2000 University Avenue, Suite 600    
Entity Address, City or Town East Palo Alto    
Entity Address, State or Province CA    
Entity Address, Postal Zip Code 94303    
City Area Code 650    
Local Phone Number 282-3228    
Title of 12(b) Security Common Stock, par value $0.0001 per share    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Filer Category Non-accelerated Filer    
Entity Small Business true    
Entity Emerging Growth Company false    
Entity Shell Company false    
Entity Public Float     $ 47,486,164
Entity Common Stock, Shares Outstanding   27,685,554  
Documents Incorporated by Reference Portions of Finjan Holdings, Inc.’s Proxy Statement in connection with its Annual Meeting of Stockholders to be held in 2019 are incorporated by reference into Part III of this report.    
Entity Central Index Key 0001366340    
Current Fiscal Year End Date --12-31    
Document Fiscal Year Focus 2019    
Document Fiscal Period Focus FY    
Amendment Flag false    
No Trading Symbol Flag false