Cover - shares	3 Months Ended
	Mar. 31, 2023	May 15, 2023
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Quarterly Report	true
Document Transition Report	false
Document Period End Date	Mar. 31, 2023
Document Fiscal Period Focus	Q1
Document Fiscal Year Focus	2023
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	2076 Foster Mill Rd.
Entity Address, City or Town	LaFayette
Entity Address, State or Province	GA
Entity Address, Postal Zip Code	30728
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		729,770,903