BASIS OF PRESENTATION AND SIGNIFICANT ACCOUNTING POLICIES, INVOL CONV OF ASSETS, FINANCING LIAB, VIE (Details) (USD $)	3 Months Ended	6 Months Ended		12 Months Ended			6 Months Ended					3 Months Ended					3 Months Ended		6 Months Ended		6 Months Ended				6 Months Ended		6 Months Ended		6 Months Ended		6 Months Ended
	Jul. 31, 2013	Oct. 31, 2014	Oct. 31, 2013	Apr. 30, 2014 Building Unit	Jul. 30, 2013	Apr. 30, 2013	Oct. 31, 2014 IRET - Minot Apartments, LLC [Member]	Oct. 31, 2014 IRET - Minot Apartments, LLC [Member] Third Party Debt [Member]	Oct. 31, 2014 IRET - Minot Apartments, LLC [Member] Debt from IRET [Member]	Oct. 31, 2014 IRET - Minot Apartments, LLC [Member] Real Estate Development Company [Member]	Oct. 31, 2014 Financing Liability [Member]	Oct. 31, 2013 Chateau Apartment Fire, 2012 [Member]	Jul. 31, 2013 Chateau Apartment Fire, 2012 [Member]	Oct. 31, 2014 Chateau Apartment, Fire 2013 [Member]	Jul. 31, 2014 Chateau Apartment, Fire 2013 [Member]	Apr. 30, 2014 Chateau Apartment, Fire 2013 [Member]	Jan. 31, 2014 Chateau Apartment, Fire 2013 [Member] Building One [Member] Unit	Jan. 31, 2014 Chateau Apartment, Fire 2013 [Member] Building Two [Member] Unit	Oct. 31, 2013 Total Equity [Member]	Apr. 30, 2013 Total Equity [Member]	Oct. 31, 2014 Noncontrolling Interests [Member]	Oct. 31, 2013 Noncontrolling Interests [Member]	Apr. 30, 2014 Noncontrolling Interests [Member]	Apr. 30, 2013 Noncontrolling Interests [Member]	Oct. 31, 2013 Scenario, Previously Reported [Member] Total Equity [Member]	Apr. 30, 2013 Scenario, Previously Reported [Member] Total Equity [Member]	Oct. 31, 2013 Scenario, Previously Reported [Member] Noncontrolling Interests [Member]	Apr. 30, 2013 Scenario, Previously Reported [Member] Noncontrolling Interests [Member]	Oct. 31, 2013 Restatement Adjustment [Member] Total Equity [Member]	Apr. 30, 2013 Restatement Adjustment [Member] Total Equity [Member]	Oct. 31, 2013 Restatement Adjustment [Member] Noncontrolling Interests [Member]	Apr. 30, 2013 Restatement Adjustment [Member] Noncontrolling Interests [Member]
Consolidated Balance Sheet [Abstract]
Redeemable noncontrolling interests consolidated real estate entities		$ 6,373,000		$ 6,203,000
Noncontrolling interests consolidated real estate entities		26,602,000		22,638,000
Total equity		726,668,000	769,891,000	720,546,000		755,444,000													769,891,000	755,444,000	89,809,000	143,817,000	128,362,000	142,657,000	775,935,000	761,381,000	149,861,000	148,594,000	(6,044,000)		(6,044,000)	(5,937,000)
Consolidated Statement of Equity [Abstract]
Net income attributable to Investors Real Estate Trust and nonredeemable noncontrolling interests		5,501,000	13,406,000																13,406,000		538,000	1,541,000			13,513,000		1,648,000		(107,000)		(107,000)
Contributions from nonredeemable noncontrolling interests - consolidated real estate entities		3,757,000	3,316,000																		3,757,000	3,316,000
Balance		726,668,000	769,891,000	720,546,000		755,444,000													769,891,000	755,444,000	89,809,000	143,817,000	128,362,000	142,657,000	775,935,000	761,381,000	149,861,000	148,594,000	(6,044,000)		(6,044,000)	(5,937,000)
Impaired Long-Lived Assets Held and Used [Line Items]
Number of 32 unit buildings				2
Number of units in building				32													15	57
Number of buildings destroyed				1
Insurance proceeds received for redevelopment													966,000	4,000,000	2,000,000	1,000,000
Gain from involuntary conversion												966,000
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		107,731,000		63,178,000							7,900,000
Variable Interest Entity [Line Items]
Estimated total costs of joint venture project							$ 52,200,000
Percentage of project financed (in hundredths)								69.00%	7.00%
Percentage of ownership in VIE (in hundredths)							52.90%			47.10%