| Document and Entity Information | Apr. 28, 2023 |
| Document and Entity Information [Abstract] | |
| Document Type | 8-K |
| Document Period End Date | Apr. 28, 2023 |
| Entity File Number | 001-38491 |
| Entity Registrant Name | MID-SOUTHERN BANCORP, INC. |
| Entity Incorporation, State or Country Code | IN |
| Entity Tax Identification Number | 82-4821705 |
| Entity Address, Address Line One | 300 North Water Street |
| Entity Address, City or Town | Salem |
| Entity Address, State or Province | IN |
| Entity Address, Postal Zip Code | 47167 |
| City Area Code | 812 |
| Local Phone Number | 883-2639 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, par value $.01 per share |
| Trading Symbol | MSVB |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | true |
| Entity Ex Transition Period | false |
| Entity Central Index Key | 0001734875 |
| Amendment Flag | false |
