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ORGANIZATION (Details)
Jan. 31, 2015
ORGANIZATION [Abstract]  
Percentage of ordinary taxable income that must be distributed to shareholders (in hundredths) 90.00%iret_PercentageOfOrdinaryTaxableIncomeThatMustBeDistributedToShareholders
Multi-family residential properties [Member]  
Real Estate Properties [Line Items]  
Number of real estate properties 99us-gaap_NumberOfRealEstateProperties
/ us-gaap_RealEstatePropertiesAxis
= us-gaap_ResidentialRealEstateMember
Number of apartment units owned 11,765us-gaap_NumberOfUnitsInRealEstateProperty
/ us-gaap_RealEstatePropertiesAxis
= us-gaap_ResidentialRealEstateMember
Commercial properties [Member]  
Real Estate Properties [Line Items]  
Number of real estate properties 160us-gaap_NumberOfRealEstateProperties
/ us-gaap_RealEstatePropertiesAxis
= us-gaap_CommercialRealEstateMember
Net rentable area (in square feet) 9.8us-gaap_NetRentableArea
/ us-gaap_RealEstatePropertiesAxis
= us-gaap_CommercialRealEstateMember