BASIS OF PRESENTATION AND SIGNIFICANT ACCOUNTING POLICIES, INVOL CONV OF ASSETS, FINANCING LIAB, VIE (Details) (USD $)	3 Months Ended	9 Months Ended		12 Months Ended	3 Months Ended
	Jul. 31, 2013	Jan. 31, 2015	Jan. 31, 2014	Apr. 30, 2012 Unit Building	Jan. 31, 2014 Unit	Apr. 30, 2014	Oct. 31, 2013	Jul. 30, 2013	Apr. 30, 2013
Consolidated Balance Sheet [Abstract]
Redeemable noncontrolling interests consolidated real estate entities		$ 6,340,000				$ 6,203,000
Noncontrolling interests consolidated real estate entities		31,356,000				22,638,000
Total equity		736,212,000	765,317,000		765,317,000	720,546,000			755,444,000
Consolidated Statement of Equity [Abstract]
Net income attributable to Investors Real Estate Trust and nonredeemable noncontrolling interests		14,685,000	17,406,000
Contributions from nonredeemable noncontrolling interests - consolidated real estate entities		8,540,000	3,316,000
Balance		736,212,000	765,317,000		765,317,000	720,546,000			755,444,000
Impaired Long-Lived Assets Held and Used [Line Items]
Number of 32 unit buildings				2
Number of units in building				32
Number of buildings destroyed				1
Insurance proceeds received for redevelopment							1,300,000
Gain from involuntary conversion			2,500,000
Other Liabilities [Line Items]
Proceeds from sale of property	7,900,000
Contract for deed								29,000,000
Sale lease-back recorded in other liabilities								7,900,000
Financing liability balance		132,210,000				63,178,000
IRET - Minot Apartments, LLC [Member]
Variable Interest Entity [Line Items]
Estimated total costs of joint venture project		52,200,000
Percentage of ownership in VIE (in hundredths)		52.90%
IRET - Minot Apartments, LLC [Member] | Third Party Debt [Member]
Variable Interest Entity [Line Items]
Percentage of project financed (in hundredths)		69.00%
IRET - Minot Apartments, LLC [Member] | Debt from IRET [Member]
Variable Interest Entity [Line Items]
Percentage of project financed (in hundredths)		7.00%
IRET - Minot Apartments, LLC [Member] | Real Estate Development Company [Member]
Variable Interest Entity [Line Items]
Percentage of ownership in VIE (in hundredths)		47.10%
IRET - 71 France, LLC [Member]
Variable Interest Entity [Line Items]
Estimated total costs of joint venture project		73,300,000
Percentage of ownership in VIE (in hundredths)		52.60%
IRET - 71 France, LLC [Member] | Third Party Debt [Member]
Variable Interest Entity [Line Items]
Percentage of project financed (in hundredths)		69.00%
IRET - 71 France, LLC [Member] | Debt from IRET [Member]
Variable Interest Entity [Line Items]
Percentage of project financed (in hundredths)		7.00%
IRET - 71 France, LLC [Member] | Real Estate Development Company [Member]
Variable Interest Entity [Line Items]
Percentage of ownership in VIE (in hundredths)		47.40%
Financing Liability [Member]
Other Liabilities [Line Items]
Financing liability balance		7,900,000
Chateau Apartment Fire, 2012 [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Insurance proceeds received for redevelopment	966,000
Chateau Apartment, Fire 2013 [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Insurance proceeds received for redevelopment		4,000,000	2,000,000		2,000,000	1,000,000
Chateau Apartment, Fire 2013 [Member] | Building One [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Number of units in building					15
Chateau Apartment, Fire 2013 [Member] | Building Two [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Number of units in building					57
Total Equity [Member]
Consolidated Balance Sheet [Abstract]
Total equity			765,317,000		765,317,000				755,444,000
Consolidated Statement of Equity [Abstract]
Net income attributable to Investors Real Estate Trust and nonredeemable noncontrolling interests			17,406,000
Balance			765,317,000		765,317,000				755,444,000
Noncontrolling Interests [Member]
Consolidated Balance Sheet [Abstract]
Total equity		92,533,000	141,121,000		141,121,000	128,362,000			142,657,000
Consolidated Statement of Equity [Abstract]
Net income attributable to Investors Real Estate Trust and nonredeemable noncontrolling interests		1,351,000	2,038,000
Contributions from nonredeemable noncontrolling interests - consolidated real estate entities		8,540,000	3,316,000
Balance		92,533,000	141,121,000		141,121,000	128,362,000			142,657,000
Scenario, Previously Reported [Member] | Total Equity [Member]
Consolidated Balance Sheet [Abstract]
Total equity			771,430,000		771,430,000				761,381,000
Consolidated Statement of Equity [Abstract]
Net income attributable to Investors Real Estate Trust and nonredeemable noncontrolling interests			17,582,000
Balance			771,430,000		771,430,000				761,381,000
Scenario, Previously Reported [Member] | Noncontrolling Interests [Member]
Consolidated Balance Sheet [Abstract]
Total equity			147,234,000		147,234,000				148,594,000
Consolidated Statement of Equity [Abstract]
Net income attributable to Investors Real Estate Trust and nonredeemable noncontrolling interests			2,214,000
Balance			147,234,000		147,234,000				148,594,000
Restatement Adjustment [Member] | Total Equity [Member]
Consolidated Balance Sheet [Abstract]
Total equity			(6,113,000)		(6,113,000)
Consolidated Statement of Equity [Abstract]
Net income attributable to Investors Real Estate Trust and nonredeemable noncontrolling interests			(176,000)
Balance			(6,113,000)		(6,113,000)
Restatement Adjustment [Member] | Noncontrolling Interests [Member]
Consolidated Balance Sheet [Abstract]
Total equity			(6,113,000)		(6,113,000)				(5,937,000)
Consolidated Statement of Equity [Abstract]
Net income attributable to Investors Real Estate Trust and nonredeemable noncontrolling interests			(176,000)
Balance			$ (6,113,000)		(6,113,000)				$ (5,937,000)