| Cover | Oct. 10, 2023 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Oct. 10, 2023 |
| Entity File Number | 000-55323 |
| Entity Registrant Name | MENTOR CAPITAL, INC. |
| Entity Central Index Key | 0001599117 |
| Entity Tax Identification Number | 77-0395098 |
| Entity Incorporation, State or Country Code | DE |
| 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 |
| City Area Code | (760) |
| Local Phone Number | 788-4700 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common stock |
| Trading Symbol | MNTR |
| Entity Emerging Growth Company | true |
| Elected Not To Use the Extended Transition Period | false |
