Cover	Jan. 21, 2022
Cover [Abstract]
Document Type	8-K
Amendment Flag	false
Document Period End Date	Jan. 21, 2022
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	150 Fayetteville Street
Entity Address, Address Line Two	Suite 1110
Entity Address, City or Town	Raleigh
Entity Address, State or Province	NC
Entity Address, Postal Zip Code	27601
Local Phone Number	(914) 630-7430
Written Communications	false
Soliciting Material	false
Pre-commencement Tender Offer	false
Pre-commencement Issuer Tender Offer	false
Entity Emerging Growth Company	false