ACQUISITIONS, DEVELOPMENTS PLACED IN SERVICE AND DISPOSITIONS, Property Acquisitions (Details)		9 Months Ended
		Jan. 31, 2016 USD ($) ft² Unit		Jan. 31, 2015 USD ($) Unit
Business Acquisition [Line Items]
Transaction costs expensed during the period		$ 162,000		$ 104,000
Acquisitions and development projects placed in service [Abstract]
Investment Allocation, Land		6,819,000	[1]	9,941,000
Investment Allocation, Building		129,979,000	[1]	103,627,000
Goodwill, acquired during period		0		852,000
Results of operations from acquired properties [Abstract]
Total revenue		1,969,000		1,756,000
Net income (loss)		(62,000)		(27,000)
Multifamily [Member]
Acquisitions and development projects placed in service [Abstract]
Investment Allocation, Land		3,320,000	[1]	8,949,000
Investment Allocation, Building		73,772,000	[1]	101,434,000
Healthcare [Member]
Acquisitions and development projects placed in service [Abstract]
Investment Allocation, Land	[1],[2],[3]	2,610,000
Investment Allocation, Building	[1],[2],[3]	54,473,000
Acquisitions [Member]
Acquisitions and development projects placed in service [Abstract]
Total Acquisition Cost		71,750,000		41,297,000
Form of Consideration, Cash		71,350,000		24,306,000
Form of Consideration, Units	[4]	400,000		100,000
Form of Consideration, Other	[5]			16,891,000
Investment Allocation, Land		6,424,000	[1],[2],[3],[6],[7],[8]	16,271,000	[9],[10],[11],[12],[13],[14]
Investment Allocation, Building		64,144,000	[1],[2],[3],[6],[7],[8]	24,661,000	[9],[10],[11],[12],[13],[14]
Investment Allocation, Intangible Assets		1,182,000		365,000
Acquisitions [Member] | 71 France Phases I, II & III [Member]
Acquisitions and development projects placed in service [Abstract]
JV partner contributions				4,700,000
Acquisitions [Member] | Multifamily [Member]
Acquisitions and development projects placed in service [Abstract]
Total Acquisition Cost		65,250,000		26,780,000
Form of Consideration, Cash		64,850,000		14,511,000
Form of Consideration, Units	[4]	400,000		100,000
Form of Consideration, Other	[5]			12,169,000
Investment Allocation, Land		5,521,000		1,754,000
Investment Allocation, Building		59,035,000		24,661,000
Investment Allocation, Intangible Assets		$ 694,000		$ 365,000
Acquisitions [Member] | Multifamily [Member] | 74 unit - Gardens - Grand Forks, ND [Member]
Acquisitions and development projects placed in service [Abstract]
Date Acquired		Sep. 10, 2015
Total Acquisition Cost		$ 9,250,000
Form of Consideration, Cash		8,850,000
Form of Consideration, Units	[4]	400,000
Investment Allocation, Land		518,000
Investment Allocation, Building		8,672,000
Investment Allocation, Intangible Assets		$ 60,000
Number of units | Unit		74
Acquisitions [Member] | Multifamily [Member] | 276 unit - GrandeVille at Cascade Lake - Rochester, MN [Member]
Acquisitions and development projects placed in service [Abstract]
Date Acquired		Oct. 29, 2015
Total Acquisition Cost		$ 56,000,000
Form of Consideration, Cash		56,000,000
Form of Consideration, Units	[4]	0
Investment Allocation, Land		5,003,000
Investment Allocation, Building		50,363,000
Investment Allocation, Intangible Assets		$ 634,000
Number of units | Unit		276
Acquisitions [Member] | Multifamily [Member] | 152 unit - Homestead Garden - Rapid City, SD [Member]
Acquisitions and development projects placed in service [Abstract]
Date Acquired	[15]			Jun. 02, 2014
Total Acquisition Cost	[15]			$ 15,000,000
Form of Consideration, Cash	[15]			5,092,000
Form of Consideration, Units	[4],[15]			0
Form of Consideration, Other	[5],[15]			9,908,000
Investment Allocation, Land	[15]			655,000
Investment Allocation, Building	[15]			14,139,000
Investment Allocation, Intangible Assets	[15]			$ 206,000
Number of units | Unit	[15]			152
Goodwill, acquired during period				$ 852,000
Assumed debt				$ 9,900,000
Acquisitions [Member] | Multifamily [Member] | 52 unit - Silver Springs - Rapid City, SD [Member]
Acquisitions and development projects placed in service [Abstract]
Date Acquired				Jun. 02, 2014
Total Acquisition Cost				$ 3,280,000
Form of Consideration, Cash				1,019,000
Form of Consideration, Units	[4]			0
Form of Consideration, Other	[5]			2,261,000
Investment Allocation, Land				215,000
Investment Allocation, Building				3,006,000
Investment Allocation, Intangible Assets				$ 59,000
Number of units | Unit				52
Assumed debt				$ 2,300,000
Acquisitions [Member] | Multifamily [Member] | 68 unit - Northridge - Bismarck, ND [Member]
Acquisitions and development projects placed in service [Abstract]
Date Acquired				Sep. 12, 2014
Total Acquisition Cost				$ 8,500,000
Form of Consideration, Cash				8,400,000
Form of Consideration, Units	[4]			100,000
Form of Consideration, Other	[5]			0
Investment Allocation, Land				884,000
Investment Allocation, Building				7,516,000
Investment Allocation, Intangible Assets				$ 100,000
Number of units | Unit				68
Acquisitions [Member] | Healthcare [Member] | 27,819 sq ft Lakeside Medical Plaza - Omaha, NE [Member]
Acquisitions and development projects placed in service [Abstract]
Date Acquired		Aug. 20, 2015
Total Acquisition Cost		$ 6,500,000
Form of Consideration, Cash		6,500,000
Form of Consideration, Units	[4]	0
Investment Allocation, Land		903,000
Investment Allocation, Building		5,109,000
Investment Allocation, Intangible Assets		$ 488,000
Area of real estate property | ft²		27,819
Acquisitions [Member] | Unimproved Land [Member]
Acquisitions and development projects placed in service [Abstract]
Total Acquisition Cost				$ 14,517,000
Form of Consideration, Cash				9,795,000
Form of Consideration, Units	[4]			0
Form of Consideration, Other	[5]			4,722,000
Investment Allocation, Land				14,517,000
Investment Allocation, Building				0
Investment Allocation, Intangible Assets				$ 0
Acquisitions [Member] | Unimproved Land [Member] | Creekside Crossing - Bismarck, ND [Member]
Acquisitions and development projects placed in service [Abstract]
Date Acquired				May 22, 2014
Total Acquisition Cost				$ 4,269,000
Form of Consideration, Cash				4,269,000
Form of Consideration, Units	[4]			0
Form of Consideration, Other	[5]			0
Investment Allocation, Land				4,269,000
Investment Allocation, Building				0
Investment Allocation, Intangible Assets				$ 0
Acquisitions [Member] | Unimproved Land [Member] | PrairieCare Medical - Brooklyn Park, MN [Member]
Acquisitions and development projects placed in service [Abstract]
Date Acquired				Jun. 05, 2014
Total Acquisition Cost				$ 2,616,000
Form of Consideration, Cash				2,616,000
Form of Consideration, Units	[4]			0
Form of Consideration, Other	[5]			0
Investment Allocation, Land				2,616,000
Investment Allocation, Building				0
Investment Allocation, Intangible Assets				$ 0
Acquisitions [Member] | Unimproved Land [Member] | 71 France Phase I - Edina, MN [Member]
Acquisitions and development projects placed in service [Abstract]
Date Acquired	[16]			Jun. 12, 2014
Total Acquisition Cost	[16]			$ 1,413,000
Form of Consideration, Cash	[16]			0
Form of Consideration, Units	[4],[16]			0
Form of Consideration, Other	[5],[16]			1,413,000
Investment Allocation, Land	[16]			1,413,000
Investment Allocation, Building	[16]			0
Investment Allocation, Intangible Assets	[16]			$ 0
Interest held percentage				52.60%
Acquisitions [Member] | Unimproved Land [Member] | Monticello 7th Addition - Monticello, MN [Member]
Acquisitions and development projects placed in service [Abstract]
Date Acquired				Oct. 09, 2014
Total Acquisition Cost				$ 1,660,000
Form of Consideration, Cash				1,660,000
Form of Consideration, Units	[4]			0
Form of Consideration, Other	[5]			0
Investment Allocation, Land				1,660,000
Investment Allocation, Building				0
Investment Allocation, Intangible Assets				$ 0
Acquisitions [Member] | Unimproved Land [Member] | 71 France Phase II & III - Edina, MN [Member]
Acquisitions and development projects placed in service [Abstract]
Date Acquired	[16]			Nov. 04, 2014
Total Acquisition Cost	[16]			$ 3,309,000
Form of Consideration, Cash	[16]			0
Form of Consideration, Units	[4],[16]			0
Form of Consideration, Other	[5],[16]			3,309,000
Investment Allocation, Land	[16]			3,309,000
Investment Allocation, Building	[16]			0
Investment Allocation, Intangible Assets	[16]			$ 0
Acquisitions [Member] | Unimproved Land [Member] | Minot 1525 24th Ave SW - Minot, ND [Member]
Acquisitions and development projects placed in service [Abstract]
Date Acquired				Dec. 23, 2014
Total Acquisition Cost				$ 1,250,000
Form of Consideration, Cash				1,250,000
Form of Consideration, Units	[4]			0
Form of Consideration, Other	[5]			0
Investment Allocation, Land				1,250,000
Investment Allocation, Building				0
Investment Allocation, Intangible Assets				$ 0

[1] Development projects that are placed in service in phases are excluded from this table until the entire project has been placed in service. See Note 6 for additional information on the Deer Ridge, 71 France, and Cardinal Point projects, which were partially placed in service during the nine months ended January 31, 2016.

[2] Costs paid in prior fiscal years totaled $17.3 million. Additional costs incurred in fiscal year 2016 totaled $7.1 million, for a total project cost at January 31, 2016 of $24.4 million.

[3] Costs paid in prior fiscal years totaled $20.8 million. Additional costs incurred in fiscal year 2016 totaled $11.9 million, for a total project cost at January 31, 2016 of $32.7 million.

[4] Value of Units of the Operating Partnership at the acquisition date.

[5] Consists of assumed debt (Homestead Garden I: $9.9 million, Silver Springs: $2.3 million) and value of land contributed by the joint venture partner (71 France: $4.7 million).

[6] Costs paid in prior fiscal years totaled $12.3 million. Additional costs incurred in fiscal year 2016 totaled $2.3 million, for a total project cost at January 31, 2016 of $14.6 million.

[7] Costs paid in prior fiscal years totaled $2.1 million. Additional costs incurred in fiscal year 2016 totaled approximately $500,000, for a total project cost at January 31, 2016 of $2.6 million.

[8] Costs paid in prior fiscal years totaled $57.7 million. Additional costs incurred in fiscal year 2016 totaled $4.8 million, for a total project cost at January 31, 2016 of $62.5 million. The project is owned by a joint venture entity in which we currently have an approximately 70.0% interest. The joint venture is consolidated in our financial statements.

[9] Costs paid in prior fiscal years totaled $1.0 million. Additional cost paid in fiscal year 2015 totaled $2.2 million, for a total project cost at January 31, 2015 of $3.2 million.

[10] Costs paid in prior fiscal years totaled $1.2 million. Additional costs paid in fiscal year 2015 totaled $5.5 million, for a total project cost at January 31, 2015 of $6.6 million. The project is owned by a joint venture entity in which we currently have an approximately 86.1% interest. The joint venture is consolidated in our financial statements.

[11] Costs paid in prior fiscal years totaled $11.3 million. Additional costs paid in fiscal year 2015 totaled $19.1 million, for a total project cost at January 31, 2015 of $30.4 million.

[12] Costs paid in prior fiscal years totaled $12.2 million. Additional costs paid in fiscal year 2015 totaled $16.1 million, for a total project cost at January 31, 2015 of $28.3 million. The project is owned by a joint venture entity in which we currently have an approximately 58.6% interest. The joint venture is consolidated in our financial statements.

[13] Costs paid in prior fiscal years totaled $26.5 million. Additional costs paid in fiscal year 2015 totaled $8.1 million, for a total project cost at January 31, 2015 of $34.6 million. The project is owned by a joint venture entity in which we have an approximately 52.9% interest. The joint venture is consolidated in our financial statements.

[14] Costs paid in prior fiscal years totaled $8.1 million. Additional costs paid in fiscal year 2015 totaled $2.3 million, for a total project cost at January 31, 2015 of $10.4 million.

[15] At acquisition, we adjusted the assumed debt to fair value and recognized approximately $852,000 of goodwill.

[16] Land was contributed to a joint venture in which we currently have an approximately 52.6% interest. The joint venture is consolidated in our financial statements.