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			4,833,000	740,000	5,573,000
Distributions - common shares and units			(35,433,000)	(8,513,000)	(43,946,000)
Distributions - preferred shares					(1,779,000)	(1,779,000)	(1,779,000)
Distribution reinvestment and share purchase plan		28,831,000			28,831,000
Distribution reinvestment and share purchase plan (in shares)		3,992,000
Shares issued		3,413,000			3,413,000
Shares issued, shares (in shares)		471,000
Partnership units issued				2,469,000	2,469,000
Redemption of units for common shares		3,454,000		(3,454,000)	0
Redemption of units for common shares, shares (in shares)		759,000
Contributions from noncontrolling interests - consolidated real estate entities				2,227,000	2,227,000
Other		(330,000)		(586,000)	(916,000)
Other, shares (in shares)		(2,000)
Balance at Jan. 31, 2012	27,317,000	657,304,000	(269,942,000)	125,483,000	540,162,000
Balance, shares (in shares) at Jan. 31, 2012	1,150,000	85,743,000
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			15,515,000	2,644,000	18,159,000
Distributions - common shares and units			(35,933,000)	(8,193,000)	(44,126,000)
Distributions - preferred shares					(6,350,000)	(1,779,000)	(1,779,000)	(4,571,000)	(4,571,000)
Distribution reinvestment and share purchase plan		34,072,000			34,072,000
Distribution reinvestment and share purchase plan (in shares)		4,315,000
Shares issued		2,846,000			2,846,000
Shares issued, shares (in shares)		396,000
Series B preferred shares issued	111,357,000				111,357,000
Series B preferred shares issued, in shares	4,600
Partnership units issued				10,116,000	10,116,000
Redemption of units for common shares		846,000		(846,000)	0
Redemption of units for common shares, shares (in shares)		203,000
Contributions from noncontrolling interests - consolidated real estate entities				7,068,000	7,068,000
Other		(71,000)		(55,000)	(126,000)
Other, shares (in shares)		(2,000)
Balance at Jan. 31, 2013	$ 138,674,000	$ 721,742,000	$ (305,145,000)	$ 143,008,000	$ 698,279,000
Balance, shares (in shares) at Jan. 31, 2013	5,750,000	94,386,000