CONDENSED CONSOLIDATED STATEMENTS OF EQUITY (unaudited) - USD ($) shares in Thousands, $ in Thousands	Series A Preferred Stock [Member] ACCUMULATED DISTRIBUTIONS IN EXCESS OF NET INCOME [Member]	Series A Preferred Stock [Member]	Series B Preferred Stock [Member] ACCUMULATED DISTRIBUTIONS IN EXCESS OF NET INCOME [Member]	Series B Preferred Stock [Member]	PREFERRED SHARES [Member]	Common Shares and Limited Partnership Units [Member]	ACCUMULATED DISTRIBUTIONS IN EXCESS OF NET INCOME [Member]	NONREDEEMABLE NONCONTROLLING INTERESTS [Member]	Total
Balance at Apr. 30, 2015					$ 138,674	$ 951,868	$ (438,432)	$ 88,844	$ 740,954
Balance (in shares) at Apr. 30, 2015					5,750	124,455
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to Investors Real Estate Trust and noncontrolling interests							21,206	287	21,493
Distributions - common shares and units							(32,525)	(3,626)	(36,151)
Distributions - preferred shares	$ (1,186)	$ (1,186)	$ (4,571)	$ (4,571)					(5,757)
Distribution reinvestment and share purchase plan						$ 5,619			5,619
Distribution reinvestment and share purchase plan (in shares)						821
Shares issued and share-based compensation						$ 482			482
Shares issued and share-based compensation (in shares)						220
Partnership units issued								400	400
Redemption of units for common shares						$ 855		(855)
Redemption of units for common shares (in shares)						154
Shares repurchased						$ (21,931)			(21,931)
Shares repurchased (in shares)						(2,852)
Other								(6,236)	(6,236)
Balance at Oct. 31, 2015					$ 138,674	$ 936,893	(455,508)	78,814	698,873
Balance (in shares) at Oct. 31, 2015					5,750	122,798
Balance at Apr. 30, 2016					$ 138,674	$ 922,084	(442,000)	99,504	718,262
Balance (in shares) at Apr. 30, 2016					5,750	121,091
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to Investors Real Estate Trust and noncontrolling interests							(10,043)	(18,116)	(28,159)
Distributions - common shares and units							(31,556)	(4,234)	(35,790)
Distributions - preferred shares	$ (1,186)	$ (1,186)	$ (4,571)	$ (4,571)					(5,757)
Shares issued and share-based compensation						$ 1,218			1,218
Shares issued and share-based compensation (in shares)						553
Redemption of units for common shares						$ 134		(134)
Redemption of units for common shares (in shares)						57
Contributions from nonredeemable noncontrolling interests - consolidated real estate entities								7,150	7,150
Distributions to nonredeemable noncontrolling interests - consolidated real estate entities								(155)	(155)
Acquisition of nonredeemable noncontrolling interests – consolidated real estate entities						$ (2,677)		(2,261)	(4,938)
Other								(615)	(615)
Balance at Oct. 31, 2016					$ 138,674	$ 920,759	$ (489,356)	$ 81,139	$ 651,216
Balance (in shares) at Oct. 31, 2016					5,750	121,701