CONSOLIDATED STATEMENTS OF EQUITY (USD $)	PREFERRED SHARES [Member]	COMMON SHARES [Member]	ACCUMULATED DISTRIBUTIONS IN EXCESS OF NET INCOME [Member]	NONCONTROLLING INTERESTS [Member]	Total	Preferred Class A [Member] ACCUMULATED DISTRIBUTIONS IN EXCESS OF NET INCOME [Member]	Preferred Class A [Member]	Preferred Class B [Member] ACCUMULATED DISTRIBUTIONS IN EXCESS OF NET INCOME [Member]	Preferred Class B [Member]
Balance at Apr. 30, 2011	$ 27,317,000	$ 621,936,000	$ (237,563,000)	$ 132,600,000	$ 544,290,000
Balance, shares (in shares) at Apr. 30, 2011	1,150,000	80,523,000
Net income attributable to Investors Real Estate Trust and nonredeemable noncontrolling interests			2,706,000	348,000	3,054,000
Distributions - common shares and units			(24,492,000)	(5,969,000)	(30,461,000)
Distributions - preferred shares					(1,186,000)	(1,186,000)
Distribution reinvestment and share purchase plan		16,902,000			16,902,000
Distribution reinvestment and share purchase plan (in shares)		2,302,000
Shares issued		773,000			773,000				0
Shares issued, shares (in shares)		99,000
Partnership units issued				1,974,000	1,974,000
Redemption of units for common shares		3,454,000		(3,454,000)	0
Redemption of units for common shares, shares (in shares)		759,000
Adjustments to redeemable noncontrolling interests		(35,000)			(35,000)
Other		(8,000)		1,865,000	1,857,000
Other, shares (in shares)		(1,000)
Balance at Oct. 31, 2011	27,317,000	643,022,000	(260,535,000)	127,364,000	537,168,000
Balance, shares (in shares) at Oct. 31, 2011	1,150,000	83,682,000
Balance at Apr. 30, 2012	27,317,000	684,049,000	(278,377,000)	132,274,000	565,263,000
Balance, shares (in shares) at Apr. 30, 2012	1,150,000	89,474,000
Net income attributable to Investors Real Estate Trust and nonredeemable noncontrolling interests			10,191,000	1,815,000	12,006,000
Distributions - common shares and units			(23,739,000)	(5,431,000)	(29,170,000)
Distributions - preferred shares					(3,471,000)	(1,186,000)	(1,186,000)	(2,285,000)	(2,285,000)
Distribution reinvestment and share purchase plan		24,421,000			24,421,000
Distribution reinvestment and share purchase plan (in shares)		3,165,000
Shares issued		2,846,000			2,846,000				111,357,000
Shares issued, shares (in shares)	4,600,000	396,000
Series B preferred shares issued	111,357,000				111,357,000
Partnership units issued				8,116,000	8,116,000
Redemption of units for common shares		579,000		(579,000)	0
Redemption of units for common shares, shares (in shares)		128,000
Other		(15,000)		1,136,000	1,121,000
Other, shares (in shares)		(2,000)
Balance at Oct. 31, 2012	$ 138,674,000	$ 711,880,000	$ (295,396,000)	$ 137,331,000	$ 692,489,000
Balance, shares (in shares) at Oct. 31, 2012	5,750,000	93,161,000