| Document and Entity Information | Nov. 05, 2021 |
| Entity Listings [Line Items] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Nov. 5, 2021 |
| Entity Registrant Name | MONMOUTH REAL ESTATE INVESTMENT CORPORATION |
| Entity Incorporation, State or Country Code | MD |
| Entity File Number | 001-33177 |
| Entity Tax Identification Number | 22-1897375 |
| Entity Address, Address Line One | 101 Crawfords Corner Road |
| Entity Address, Address Line Two | Suite 1405 |
| Entity Address, City or Town | Holmdel |
| Entity Address, State or Province | NJ |
| Entity Address, Postal Zip Code | 07733 |
| City Area Code | 732 |
| Local Phone Number | 577-9996 |
| Written Communications | false |
| Soliciting Material | true |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
| Entity Central Index Key | 0000067625 |
| Common Stock [Member] | |
| Entity Listings [Line Items] | |
| Title of 12(b) Security | Common Stock |
| Trading Symbol | MNR |
| Security Exchange Name | NYSE |
| 6.125% Series C Cumulative Redeemable Preferred Stock [Member] | |
| Entity Listings [Line Items] | |
| Title of 12(b) Security | 6.125% Series C Cumulative Redeemable Preferred Stock |
| Trading Symbol | MNR-PC |
| Security Exchange Name | NYSE |
