ACQUISITIONS AND DISPOSITIONS (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Jan. 31, 2014		Jan. 31, 2013
Acquisitions and development projects placed in service [Abstract]
Land	$ 6,068		$ 20,284
Buildings	28,146		51,892
Intangible assets	900		813
Acquisition costs	35,114		72,989
Results of operations from acquired properties [Abstract]
Total revenue	1,149		4,669
Net income	(194)		(116)
Dispositions [Abstract]
Sales price	80,883		10,173
Book value and sales cost	73,884		6,721
Gain/(Loss)	6,999		3,452
Multi-Family Residential [Member]
Acquisitions and development projects placed in service [Abstract]
Land	1,447		4,715
Buildings	17,635		51,892
Intangible assets	518		813
Acquisition costs	19,600		57,420
Dispositions [Abstract]
Sales price	3,510		8,850
Book value and sales cost	3,738		5,272
Gain/(Loss)	(228)		3,578
Commercial Office [Member]
Dispositions [Abstract]
Sales price	12,950
Book value and sales cost	14,504
Gain/(Loss)	(1,554)
Commercial Retail [Member]
Dispositions [Abstract]
Sales price	3,285
Book value and sales cost	3,563
Gain/(Loss)	(278)
Commercial Industrial [Member]
Dispositions [Abstract]
Sales price	61,138
Book value and sales cost	52,079
Gain/(Loss)	9,059
Unimproved Land [Member]
Acquisitions and development projects placed in service [Abstract]
Land	3,651		15,569
Buildings	0		0
Intangible assets	0		0
Acquisition costs	3,651		15,569
Other Disposition [Member]
Dispositions [Abstract]
Sales price			698
Book value and sales cost			757
Gain/(Loss)			(59)
Alps Park - Rapid City, SD [Member] | Multi-Family Residential [Member]
Acquisitions and development projects placed in service [Abstract]
Date Acquisition	May 01, 2013
Land	287
Buildings	5,551
Intangible assets	362
Acquisition costs	6,200
Number of apartment units	71
Anoka Strip Center- Anoka, MN [Member] | Commercial Retail [Member]
Dispositions [Abstract]
Date Disposal	Dec. 23, 2013
Sales price	325
Book value and sales cost	347
Gain/(Loss)	(22)
Area of a real estate property (in square feet)	10,625
API Building, Duluth, Minnesota [Member] | Commercial Industrial [Member]
Dispositions [Abstract]
Date Disposal	Sep. 24, 2013
Sales price	2,553
Book value and sales cost	1,488
Gain/(Loss)	1,065
Area of a real estate property (in square feet)	35,000
Badger Hills - Rochester, MN [Member] | Unimproved Land [Member]
Acquisitions and development projects placed in service [Abstract]
Date Acquisition			Dec. 14, 2012	[1]
Land			1,050	[1]
Buildings			0	[1]
Intangible assets			0	[1]
Acquisition costs			1,050	[1]
Bloomington Business Plaza, Bloomington, Minnesota [Member] | Commercial Office [Member]
Dispositions [Abstract]
Date Disposal	Sep. 12, 2013
Sales price	4,500
Book value and sales cost	7,339
Gain/(Loss)	(2,839)
Area of a real estate property (in square feet)	121,669
Bodycote Industrial Building - Eden Prairie, MN [Member] | Commercial Industrial [Member]
Dispositions [Abstract]
Date Disposal	May 13, 2013
Sales price	3,150
Book value and sales cost	1,375
Gain/(Loss)	1,775
Area of a real estate property (in square feet)	41,880
Brooklyn Park 7401 Boone Avenue, Brooklyn Park, Minnesota [Member] | Commercial Industrial [Member]
Dispositions [Abstract]
Date Disposal	Sep. 12, 2013
Sales price	12,800
Book value and sales cost	12,181
Gain/(Loss)	619
Area of a real estate property (in square feet)	322,751
Burnsville 2 Strip Center - Burnsville, MN [Member] | Commercial Retail [Member]
Dispositions [Abstract]
Date Disposal	Jan. 08, 2014
Sales price	650
Book value and sales cost	796
Gain/(Loss)	(146)
Area of a real estate property (in square feet)	8,400
Candlelight - Fargo, ND [Member] | Multi-Family Residential [Member]
Dispositions [Abstract]
Date Disposal			Nov. 27, 2012
Sales price			1,950
Book value and sales cost			1,178
Gain/(Loss)			772
Number Of Apartment Units Dispositions (in units)			66
Chateau II - Minot, ND [Member] | Unimproved Land [Member]
Acquisitions and development projects placed in service [Abstract]
Date Acquisition	May 21, 2013
Land	179
Buildings	0
Intangible assets	0
Acquisition costs	179
Cedar Lake Business Center, St. Louis Park, Minnesota [Member] | Commercial Industrial [Member]
Dispositions [Abstract]
Date Disposal	Sep. 12, 2013
Sales price	2,550
Book value and sales cost	2,607
Gain/(Loss)	(57)
Area of a real estate property (in square feet)	50,400
Clive 2075NW 94th Street - Clive, IA [Member] | Commercial Industrial [Member]
Dispositions [Abstract]
Date Disposal	Jan. 30, 2014
Sales price	2,735
Book value and sales cost	2,675
Gain/(Loss)	60
Area of a real estate property (in square feet)	42,510
Colony Lincoln, NE [Member] | Multi-Family Residential [Member]
Acquisitions and development projects placed in service [Abstract]
Date Acquisition			Jun. 04, 2012
Land			1,515
Buildings			15,731
Intangible assets			254
Acquisition costs			17,500
Number of apartment units			232
Commons at Southgate - Minot, ND [Member] | Unimproved Land [Member]
Acquisitions and development projects placed in service [Abstract]
Date Acquisition			Jan. 22, 2013	[2]
Land			3,691	[2]
Buildings			0	[2]
Intangible assets			0	[2]
Acquisition costs			3,691	[2]
Cypress Court - St. Cloud, MN [Member] | Unimproved Land [Member]
Acquisitions and development projects placed in service [Abstract]
Date Acquisition			Aug. 10, 2012	[3]
Land			447	[3]
Buildings			0	[3]
Intangible assets			0	[3]
Acquisition costs			447	[3]
Cypress Court Apartment Development - St. Cloud, MN [Member] | Unimproved Land [Member]
Acquisitions and development projects placed in service [Abstract]
Date Acquisition			Aug. 10, 2012	[4]
Land			1,136	[4]
Buildings			0	[4]
Intangible assets			0	[4]
Acquisition costs			1,136	[4]
Dixon Avenue Industrial Park, Des Moines, Iowa [Member] | Commercial Industrial [Member]
Dispositions [Abstract]
Date Disposal	Oct. 31, 2013
Sales price	14,675
Book value and sales cost	10,328
Gain/(Loss)	4,347
Area of a real estate property (in square feet)	606,006
Eagan Community- Eagan, MN [Member] | Commercial Retail [Member]
Dispositions [Abstract]
Date Disposal	May 14, 2013
Sales price	2,310
Book value and sales cost	2,420
Gain/(Loss)	(110)
Area of a real estate property (in square feet)	23,187
East Park - Sioux Falls, SD [Member] | Multi-Family Residential [Member]
Dispositions [Abstract]
Date Disposal	Dec. 18, 2013
Sales price	2,214
Book value and sales cost	2,358
Gain/(Loss)	(144)
Number Of Apartment Units Dispositions (in units)	84
Fargo 1320 45th St. N - Fargo, ND [Member] | Commercial Industrial [Member]
Dispositions [Abstract]
Date Disposal	May 13, 2013
Sales price	4,700
Book value and sales cost	4,100
Gain/(Loss)	600
Area of a real estate property (in square feet)	42,244
Heritage Place - Sartell, MN [Member] | Commercial Healthcare [Member]
Acquisitions and development projects placed in service [Abstract]
Date Acquisition	Oct. 31, 2013
Land	970
Buildings	10,511
Intangible assets	382
Acquisition costs	11,863
Area Of Real Estate Property Acquisitions (in square feet)	98,174
Georgetown Square Condominiums 3 and 4 [Member] | Other Disposition [Member]
Dispositions [Abstract]
Date Disposal			Aug. 02, 2012
Sales price			368
Book value and sales cost			421
Gain/(Loss)			(53)
Georgetown Square Condominiums 5 and 6 [Member] | Other Disposition [Member]
Dispositions [Abstract]
Date Disposal			Jun. 21, 2012
Sales price			330
Book value and sales cost			336
Gain/(Loss)			(6)
Grand Forks Unimproved - Grand Forks, ND [Member] | Unimproved Land [Member]
Acquisitions and development projects placed in service [Abstract]
Date Acquisition			Dec. 31, 2012
Land			4,278
Buildings			0
Intangible assets			0
Acquisition costs			4,278
Jamestown Unimproved - Jamestown, ND [Member] | Unimproved Land [Member]
Acquisitions and development projects placed in service [Abstract]
Date Acquisition	Aug. 09, 2013
Land	700
Buildings	0
Intangible assets	0
Acquisition costs	700
Kentwood Thomasville Kentwood, MI [Member] | Commercial Retail [Member]
Dispositions [Abstract]
Date Disposal			Jun. 20, 2012
Sales price			625
Book value and sales cost			692
Gain/(Loss)			(67)
Area of a real estate property (in square feet)			16,080
Lakeside Village Lincoln, NE [Member] | Multi-Family Residential [Member]
Acquisitions and development projects placed in service [Abstract]
Date Acquisition			Jun. 04, 2012
Land			1,215
Buildings			15,837
Intangible assets			198
Acquisition costs			17,250
Number of apartment units			208
Legends at Heritage Place - Sartell, MN [Member] | Unimproved Land [Member]
Acquisitions and development projects placed in service [Abstract]
Date Acquisition	Oct. 31, 2013
Land	537
Buildings	0
Intangible assets	0
Acquisition costs	537
Lighthouse - Duluth, MN [Member] | Commercial Industrial [Member]
Dispositions [Abstract]
Date Disposal	Oct. 08, 2013
Sales price	1,825
Book value and sales cost	1,547
Gain/(Loss)	278
Area of a real estate property (in square feet)	59,292
Metal Improvement - New Brighton, MN [Member] | Commercial Industrial [Member]
Dispositions [Abstract]
Date Disposal	May 13, 2013
Sales price	2,350
Book value and sales cost	1,949
Gain/(Loss)	401
Area of a real estate property (in square feet)	49,620
Minot Unimproved (Southgate Lot 4) - Minot, ND [Member] | Unimproved Land [Member]
Acquisitions and development projects placed in service [Abstract]
Date Acquisition			Jan. 11, 2013
Land			1,882
Buildings			0
Intangible assets			0
Acquisition costs			1,882
Minnetonka 13600 County Road 62 - Minnetonka, MN [Member] | Commercial Industrial [Member]
Dispositions [Abstract]
Date Disposal	Jan. 30, 2014
Sales price	3,800
Book value and sales cost	3,084
Gain/(Loss)	716
Area of a real estate property (in square feet)	69,984
Nicollet VII, Burnsville, Minnesota [Member] | Commercial Office [Member]
Dispositions [Abstract]
Date Disposal	Sep. 12, 2013
Sales price	7,290
Book value and sales cost	6,001
Gain/(Loss)	1,289
Area of a real estate property (in square feet)	118,125
Pillsbury Business Center, Bloomington, Minnesota [Member] | Commercial Office [Member]
Dispositions [Abstract]
Date Disposal	Sep. 12, 2013
Sales price	1,160
Book value and sales cost	1,164
Gain/(Loss)	(4)
Area of a real estate property (in square feet)	42,929
Pinecone Villas - Sartell, MN [Member] | Multi-Family Residential [Member]
Acquisitions and development projects placed in service [Abstract]
Date Acquisition	Oct. 31, 2013
Land	584
Buildings	2,191
Intangible assets	25
Acquisition costs	2,800
Number of apartment units	24
Ponds at Heritage Place - Sartell, MN [Member] | Multi-Family Residential [Member]
Acquisitions and development projects placed in service [Abstract]
Date Acquisition			Oct. 10, 2012
Land			395
Buildings			4,564
Intangible assets			61
Acquisition costs			5,020
Number of apartment units			58
Prairiewood Meadows - Fargo, ND [Member] | Multi-Family Residential [Member]
Dispositions [Abstract]
Date Disposal			Sep. 27, 2012
Sales price			3,450
Book value and sales cost			2,846
Gain/(Loss)			604
Number Of Apartment Units Dispositions (in units)			85
RED 20 - Minneapolis, MN [Member] | Unimproved Land [Member]
Acquisitions and development projects placed in service [Abstract]
Date Acquisition	Aug. 20, 2013	[5]
Land	1,900	[5]
Buildings	0	[5]
Intangible assets	0	[5]
Acquisition costs	1,900	[5]
Roseville 2929 Long Lake Road - Roseville, MN [Member] | Commercial Industrial [Member]
Dispositions [Abstract]
Date Disposal	May 13, 2013
Sales price	9,275
Book value and sales cost	9,998
Gain/(Loss)	(723)
Area of a real estate property (in square feet)	172,057
Southpoint - Grand Forks, ND [Member] | Multi-Family Residential [Member]
Acquisitions and development projects placed in service [Abstract]
Date Acquisition	Sep. 05, 2013
Land	576
Buildings	9,893
Intangible assets	131
Acquisition costs	10,600
Number of apartment units	96
Spring Creek Fruitland - Fruitland, ID [Member] | Unimproved Land [Member]
Acquisitions and development projects placed in service [Abstract]
Date Acquisition	Jan. 21, 2014
Land	335
Buildings	0
Intangible assets	0
Acquisition costs	335
Sycamore Village - Sioux Falls, SD [Member] | Multi-Family Residential [Member]
Dispositions [Abstract]
Date Disposal	Dec. 18, 2013
Sales price	1,296
Book value and sales cost	1,380
Gain/(Loss)	(84)
Number Of Apartment Units Dispositions (in units)	48
Terrace on the Green - Fargo, ND [Member] | Multi-Family Residential [Member]
Dispositions [Abstract]
Date Disposal			Sep. 27, 2012
Sales price			3,450
Book value and sales cost			1,248
Gain/(Loss)			2,202
Number Of Apartment Units Dispositions (in units)			116
The Landing at Southgate, Minot, ND [Member] | Unimproved Land [Member]
Acquisitions and development projects placed in service [Abstract]
Date Acquisition			Jan. 22, 2013	[2]
Land			2,262	[2]
Buildings			0	[2]
Intangible assets			0	[2]
Acquisition costs			2,262	[2]
Villa West Topeka, KS [Member] | Multi-Family Residential [Member]
Acquisitions and development projects placed in service [Abstract]
Date Acquisition			May 08, 2012
Land			1,590
Buildings			15,760
Intangible assets			300
Acquisition costs			17,650
Number of apartment units			308
University Commons - Williston, ND [Member] | Unimproved Land [Member]
Acquisitions and development projects placed in service [Abstract]
Date Acquisition			Aug. 01, 2012
Land			823
Buildings			0
Intangible assets			0
Acquisition costs			823
Winsted Industrial Building - Winsted, MN [Member] | Commercial Industrial [Member]
Dispositions [Abstract]
Date Disposal	Jan. 17, 2014
Sales price	725
Book value and sales cost	747
Gain/(Loss)	(22)
Area of a real estate property (in square feet)	41,685
Development Projects Placed in Service [Member]
Acquisitions and development projects placed in service [Abstract]
Land	0		0
Buildings	31,348		22,178
Intangible assets	0		0
Acquisition costs	31,348		22,178
Development Projects Placed in Service [Member] | Multi-Family Residential [Member]
Acquisitions and development projects placed in service [Abstract]
Land			0
Buildings			11,649
Intangible assets			0
Acquisition costs			11,649
Development Projects Placed in Service [Member] | Commercial Healthcare [Member]
Acquisitions and development projects placed in service [Abstract]
Land			0
Buildings			6,576
Intangible assets			0
Acquisition costs			6,576
Development Projects Placed in Service [Member] | Cypress Court - St. Cloud, MN [Member] | Multi-Family Residential [Member]
Acquisitions and development projects placed in service [Abstract]
Date Acquisition	Nov. 01, 2013	[6]
Land	0	[6]
Buildings	7,836	[6]
Intangible assets	0	[6]
Acquisition costs	7,836	[6]
Number of apartment units	132	[6]
Development Projects Placed in Service [Member] | Quarry Ridge II Rochester, MN [Member] | Multi-Family Residential [Member]
Acquisitions and development projects placed in service [Abstract]
Date Acquisition			Jun. 29, 2012	[7]
Land			0	[7]
Buildings			4,591	[7]
Intangible assets			0	[7]
Acquisition costs			4,591	[7]
Number of apartment units			159	[7]
Development Projects Placed in Service [Member] | Jamestown Medical Office Building - Jamestown, ND [Member] | Commercial Healthcare [Member]
Acquisitions and development projects placed in service [Abstract]
Date Acquisition			Jan. 01, 2013	[8]
Land			0	[8]
Buildings			4,901	[8]
Intangible assets			0	[8]
Acquisition costs			4,901	[8]
Area Of Real Estate Property Acquisitions (in square feet)			45,222	[8]
Development Projects Placed in Service [Member] | Minot IPS - Minot, ND [Member] | Commercial Industrial [Member]
Acquisitions and development projects placed in service [Abstract]
Date Acquisition			Dec. 17, 2012	[9]
Land			0	[9]
Buildings			3,953	[9]
Intangible assets			0	[9]
Acquisition costs			3,953	[9]
Area Of Real Estate Property Acquisitions (in square feet)			27,567	[9]
Development Projects Placed in Service [Member] | River Ridge - Bismarck, ND [Member] | Multi-Family Residential [Member]
Acquisitions and development projects placed in service [Abstract]
Date Acquisition	Dec. 02, 2013	[10]
Land	0	[10]
Buildings	14,703	[10]
Intangible assets	0	[10]
Acquisition costs	14,703	[10]
Number of apartment units	146	[10]
Development Projects Placed in Service [Member] | Spring Wind Expansion - Laramie, WY [Member] | Commercial Healthcare [Member]
Acquisitions and development projects placed in service [Abstract]
Date Acquisition			Nov. 16, 2012	[11]
Land			0	[11]
Buildings			1,675	[11]
Intangible assets			0	[11]
Acquisition costs			1,675	[11]
Area Of Real Estate Property Acquisitions (in square feet)			26,662	[11]
Development Projects Placed in Service [Member] | The Landing at Southgate, Minot, ND [Member] | Multi-Family Residential [Member]
Acquisitions and development projects placed in service [Abstract]
Date Acquisition	Sep. 04, 2013	[12]
Land	0	[12]
Buildings	8,809	[12]
Intangible assets	0	[12]
Acquisition costs	8,809	[12]
Number of apartment units	108	[12]
Development Projects Placed in Service [Member] | Williston Garden Buildings 3 and 4 Williston, ND [Member] | Multi-Family Residential [Member]
Acquisitions and development projects placed in service [Abstract]
Date Acquisition			Jul. 31, 2012	[13]
Land			0	[13]
Buildings			7,058	[13]
Intangible assets			0	[13]
Acquisition costs			$ 7,058	[13]
Number of apartment units			73	[13]

[1] Acquisition of unimproved land consisted of two parcels acquired separately on December 14 and December 20, 2012, respectively.

[2] Land is owned by a joint venture entity in which the Company has an approximately 51% interest.

[3] Land was contributed to a joint venture entity in which the Company has an approximately 86% interest, as of January 31, 2014.

[4] Land is owned by a joint venture in which the Company has an approximately 86% interest, as of January 31, 2014.

[5] Land is owned by a joint venture in which the Company has an approximately 58.6% interest. The joint venture is consolidated in IRET's financial statements.

[6] Development property placed in service November 1, 2013. Additional costs paid in fiscal year 2013 totaled $5.8 million, for a total project cost at January 31, 2014 of $13.6 million. The project is owned by a joint venture entity in which the Company has an approximately 86% interest.

[7] Development property placed in service June 29, 2012. Additional costs paid in fiscal years 2012 and 2011, and land acquired in fiscal year 2007, totaled $13.0 million, for a total project cost at January 31, 2013 of $17.6 million.

[8] Development property placed in service January 1, 2013. Additional costs paid in fiscal year 2012 totaled $1.0 million, for a total project cost at January 31, 2013 of $5.9 million.

[9] Development property placed in service December 17, 2012. Additional costs paid in fiscal year 2012 totaled $1.8 million, for a total project cost at January 31, 2013 of $5.8 million.

[10] Development property placed in service December 2, 2013. Additional costs paid in fiscal year 2013 totaled $10.1 million, including land acquired in fiscal year 2009, for a total project cost at January 31, 2014 of $24.8 million.

[11] Expansion project placed in service November 16, 2012. Additional costs paid in fiscal year 2012 totaled $1.8 million, for a total project cost at January 31, 2013 of $3.5 million.

[12] Development property placed in service September 4, 2013. Additional costs paid in fiscal year 2013 totaled $6.3 million, for a total project cost at January 31, 2014 of $15.1 million. The project is owned by a joint venture entity in which the Company has an approximately 51% interest.

[13] Development property placed in service July 31, 2012. Buildings 1 and 2 were placed in service in fiscal year 2012. Additional costs paid in fiscal year 2012 totaled $12.0 million, for a total project cost at January 31, 2013 of $19.1 million.