| Cover Page Cover Page | May 11, 2020 |
| Entity Information [Line Items] | |
| Document Type | 8-K |
| Document Period End Date | May 11, 2020 |
| Entity Registrant Name | INVESTORS REAL ESTATE TRUST |
| Entity Incorporation, State or Country Code | ND |
| Entity File Number | 001-35624 |
| Entity Tax Identification Number | 45-0311232 |
| Entity Address, Address Line One | 1400 31st Avenue SW |
| Entity Address, Address Line Two | Suite 60 |
| Entity Address, Address Line Three | Post Office Box 1988 |
| Entity Address, City or Town | Minot |
| Entity Address, State or Province | ND |
| Entity Address, Postal Zip Code | 58702 |
| City Area Code | 701 |
| Local Phone Number | 837-4738 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
| Entity Central Index Key | 0000798359 |
| Amendment Flag | false |
| Common Shares | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | Common Shares of Beneficial Interest, no par value |
| Trading Symbol | IRET |
| Security Exchange Name | NYSE |
| Series C Cumulative Redeemable Preferred Shares | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | Series C Cumulative Redeemable Preferred Shares |
| Trading Symbol | IRET-PC |
| Security Exchange Name | NYSE |
