v3.26.1
Cover - $ / shares
6 Months Ended
Jun. 30, 2026
Aug. 06, 2026
Cover [Abstract]    
Document Type 10-Q  
Amendment Flag false  
Document Quarterly Report true  
Document Transition Report false  
Document Period End Date Jun. 30, 2026  
Document Fiscal Period Focus Q2  
Document Fiscal Year Focus 2026  
Current Fiscal Year End Date --12-31  
Entity File Number 001-32698  
Entity Registrant Name MGT CAPITAL INVESTMENTS, INC.  
Entity Central Index Key 0001001601  
Entity Tax Identification Number 13-4148725  
Entity Incorporation, State or Country Code DE  
Entity Address, Address Line One 540 Montreal Ave  
Entity Address, Address Line Two Suite 133  
Entity Address, City or Town Melbourne  
Entity Address, State or Province FL  
Entity Address, Postal Zip Code 32935  
City Area Code (914)  
Local Phone Number 630-7430  
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 Common Stock, Shares Outstanding   6,290,802,029
Entity Listing, Par Value Per Share $ 0.001