Cover Page - USD ($)	12 Months Ended
	Dec. 31, 2019	Feb. 12, 2020	Jun. 30, 2019
Document Information [Line Items]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2019
Document Transition Report	false
Entity File Number	001-35624
Entity Registrant Name	INVESTORS REAL ESTATE TRUST
Entity Incorporation, State or Country Code	ND
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	58702-1988
City Area Code	701
Local Phone Number	837-4738
Security Exchange Name	NYSE
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Shell Company	false
Entity Public Float			$ 679,479,919
Entity Common Stock, Shares Outstanding		12,098,979
Entity Central Index Key	0000798359
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Amendment Flag	false
Common Shares of Beneficial Interest, no par value
Document Information [Line Items]
Title of 12(b) Security	Common Shares of Beneficial Interest, no par value
Trading Symbol	IRET
Series C Cumulative Redeemable Preferred Shares
Document Information [Line Items]
Title of 12(b) Security	Series C Cumulative Redeemable Preferred Shares
Trading Symbol	IRET-PC