Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2020	Nov. 04, 2020
Details
Registrant CIK	0001599117
Fiscal Year End	--12-31
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2020
Document Transition Report	false
Entity File Number	000-55323
Entity Registrant Name	Mentor Capital, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	77-0395098
Entity Address, Address Line One	5964 Campus Court
Entity Address, City or Town	Plano
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	75093
Entity Address, Address Description	Address of principal executive offices
Phone Fax Number Description	Registrant’s telephone number, including area code
City Area Code	760
Local Phone Number	788-4700
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		22,850,947
Amendment Flag	false
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q3