SCHEDULE III - REAL ESTATE AND ACCUMULATED DEPRECIATION (Details) - USD ($) $ in Thousands		12 Months Ended
		Apr. 30, 2015	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2015	Apr. 30, 2014	Apr. 30, 2013
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				$ 963,222
Initial Cost to Company [Abstract]
Land					223,193
Buildings & Improvements					1,754,661
Costs capitalized subsequent to acquisition					300,004
Gross amount at which carried at close of period [Abstract]
Land					247,553
Buildings & Improvements					2,030,305
Total		$ 2,277,858			2,277,858
Accumulated Depreciation		$ (448,987)			(448,987)
Maximum borrowing capacity					90,000
Advances under the facility specified as percentage of value of properties provided as security (in hundredths)		60.00%
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 2,277,858
Deductions during year [Abstract]
Balance at close of year		448,987
Total real estate investments	[2]				1,828,871	$ 1,699,216	$ 1,680,834
Net basis of real estate investments for federal income tax purposes					1,700,000	1,500,000	1,500,000
Minimum [Member]
Gross amount at which carried at close of period [Abstract]
Maximum borrowing capacity					90,000
Maximum [Member]
Gross amount at which carried at close of period [Abstract]
Maximum borrowing capacity					100,000
Wholly Owned Properties [Member]
Gross amount at which carried at close of period [Abstract]
Total		1,996,031	$ 1,996,031	$ 1,892,009	2,098,037	1,996,031	2,032,970
Accumulated Depreciation		(424,288)	(424,288)	(373,490)	(448,987)	(424,288)	(420,421)
Reconciliations of total real estate carrying value [Abstract]
Balance at beginning of year		1,996,031	2,032,970	1,892,009
Improvements and Other		31,706	34,637	36,375
Total Additions		2,223,074	2,169,729	2,060,505
Cost of real estate sold		(15,719)	(85,030)	(21,953)
Impairment charge		(3,008)	(43,189)	(305)
Write down of asset and accumulated depreciation on impaired assets		(2,055)	(31,688)	0
Transfers		(97,824)	(10,307)	(1,893)
Other	[3]	(6,431)	(3,484)	(3,384)
Balance at close of year		2,098,037	1,996,031	2,032,970
Reconciliations of accumulated depreciation/amortization [Abstract]
Balance at beginning of year		424,288	420,421	373,490
Additions during year [Abstract]
Provisions for depreciation		60,658	57,575	56,611
Deductions during year [Abstract]
Accumulated depreciation on real estate sold		(29,463)	(19,413)	(6,444)
Write down of asset and accumulated depreciation on impaired assets		(2,055)	(31,688)	0
Other	[3]	(4,441)	(2,607)	(3,236)
Balance at close of year		448,987	424,288	420,421
Development in Progress [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					11,789
Buildings & Improvements					125,872
Costs capitalized subsequent to acquisition					16,333
Gross amount at which carried at close of period [Abstract]
Land					11,789
Buildings & Improvements					142,205
Total		153,994	104,609	27,599	153,994	104,609	46,782
Accumulated Depreciation		0			0
Reconciliations of total real estate carrying value [Abstract]
Balance at beginning of year		104,609	46,782	27,599
Acquisitions		12,647	2,079	9,177
Improvements and Other		189,306	123,240	52,970
Involuntary conversion		0	(7,052)	0
Transfers		7,015	2,870	0
Development placed in service	[4]	(159,578)	(63,210)	(42,964)
Other	[5]	(5)	(100)	0
Balance at close of year		153,994	104,609	46,782
Deductions during year [Abstract]
Balance at close of year		0
Development in Progress [Member] | 71 France - Edina, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					4,721
Buildings & Improvements					27,655
Costs capitalized subsequent to acquisition					2,761
Gross amount at which carried at close of period [Abstract]
Land					4,721
Buildings & Improvements					30,416
Total		35,137			35,137
Accumulated Depreciation		$ 0			0
Date of Construction or Acquisition		2014
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 35,137
Deductions during year [Abstract]
Balance at close of year		0
Development in Progress [Member] | Cardinal Point - Grand Forks, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					1,600
Buildings & Improvements					21,455
Costs capitalized subsequent to acquisition					3,395
Gross amount at which carried at close of period [Abstract]
Land					1,600
Buildings & Improvements					24,850
Total		26,450			26,450
Accumulated Depreciation		$ 0			0
Date of Construction or Acquisition		2013
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 26,450
Deductions during year [Abstract]
Balance at close of year		0
Development in Progress [Member] | Chateau II - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					240
Buildings & Improvements					12,080
Costs capitalized subsequent to acquisition					809
Gross amount at which carried at close of period [Abstract]
Land					240
Buildings & Improvements					12,889
Total		13,129			13,129
Accumulated Depreciation		$ 0			0
Date of Construction or Acquisition		2013
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 13,129
Deductions during year [Abstract]
Balance at close of year		0
Development in Progress [Member] | Deer Ridge - Jamestown, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					711
Buildings & Improvements					13,580
Costs capitalized subsequent to acquisition					1,064
Gross amount at which carried at close of period [Abstract]
Land					711
Buildings & Improvements					14,644
Total		15,355			15,355
Accumulated Depreciation		$ 0			0
Date of Construction or Acquisition		2013
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 15,355
Deductions during year [Abstract]
Balance at close of year		0
Development in Progress [Member] | Edina 6565 France SMC III - Edina, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					0
Buildings & Improvements					20,799
Costs capitalized subsequent to acquisition					1,750
Gross amount at which carried at close of period [Abstract]
Land					0
Buildings & Improvements					22,549
Total		22,549			22,549
Accumulated Depreciation		$ 0			0
Date of Construction or Acquisition		2014
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 22,549
Deductions during year [Abstract]
Balance at close of year		0
Development in Progress [Member] | Minot Southgate Retail - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					889
Buildings & Improvements					1,199
Costs capitalized subsequent to acquisition					76
Gross amount at which carried at close of period [Abstract]
Land					889
Buildings & Improvements					1,275
Total		2,164			2,164
Accumulated Depreciation		$ 0			0
Date of Construction or Acquisition		2014
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 2,164
Deductions during year [Abstract]
Balance at close of year		0
Development in Progress [Member] | Other [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					402
Buildings & Improvements					3,233
Costs capitalized subsequent to acquisition					2,983
Gross amount at which carried at close of period [Abstract]
Land					402
Buildings & Improvements					6,216
Total		6,618			6,618
Accumulated Depreciation		0			0
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		6,618
Deductions during year [Abstract]
Balance at close of year		0
Development in Progress [Member] | PrairieCare Medical - Brooklyn Park, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					2,610
Buildings & Improvements					14,715
Costs capitalized subsequent to acquisition					2,132
Gross amount at which carried at close of period [Abstract]
Land					2,610
Buildings & Improvements					16,847
Total		19,457			19,457
Accumulated Depreciation		$ 0			0
Date of Construction or Acquisition		2014
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 19,457
Deductions during year [Abstract]
Balance at close of year		0
Development in Progress [Member] | Renaissance Heights - Williston ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					616
Buildings & Improvements					11,156
Costs capitalized subsequent to acquisition					1,363
Gross amount at which carried at close of period [Abstract]
Land					616
Buildings & Improvements					12,519
Total		13,135			13,135
Accumulated Depreciation		$ 0			0
Date of Construction or Acquisition		2013
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 13,135
Deductions during year [Abstract]
Balance at close of year		0
Unimproved Land [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					23,564
Buildings & Improvements					0
Costs capitalized subsequent to acquisition					2,263
Gross amount at which carried at close of period [Abstract]
Land					25,827
Buildings & Improvements					0
Total		25,827	21,503	21,503	25,827	$ 22,864	$ 21,503
Accumulated Depreciation		0			0
Reconciliations of total real estate carrying value [Abstract]
Balance at beginning of year		22,864	21,503	10,990
Acquisitions		10,487	3,022	13,329
Improvements and Other		1,533	1,209	854
Cost of real estate sold		(670)	0	0
Impairment charge		(1,293)	0	0
Transfers		(79)	0	0
Balance at close of year		25,827	22,864	21,503
Deductions during year [Abstract]
Balance at close of year		0
Unimproved Land [Member] | Legends at Heritage Place - Sartell, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					537
Buildings & Improvements					0
Costs capitalized subsequent to acquisition					0
Gross amount at which carried at close of period [Abstract]
Land					537
Buildings & Improvements					0
Total		537			537
Accumulated Depreciation		$ 0			0
Date of Construction or Acquisition		2013
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 537
Deductions during year [Abstract]
Balance at close of year		0
Unimproved Land [Member] | Spring Creek Fruitland - Fruitland, ID [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					339
Buildings & Improvements					0
Costs capitalized subsequent to acquisition					0
Gross amount at which carried at close of period [Abstract]
Land					339
Buildings & Improvements					0
Total		339			339
Accumulated Depreciation		$ 0			0
Date of Construction or Acquisition		2014
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 339
Deductions during year [Abstract]
Balance at close of year		0
Unimproved Land [Member] | Badger Hills - Rochester, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					1,050
Buildings & Improvements					0
Costs capitalized subsequent to acquisition					0
Gross amount at which carried at close of period [Abstract]
Land					1,050
Buildings & Improvements					0
Total		1,050			1,050
Accumulated Depreciation		$ 0			0
Date of Construction or Acquisition		2012
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 1,050
Deductions during year [Abstract]
Balance at close of year		0
Unimproved Land [Member] | Bismarck 4916 - Bismarck, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					3,250
Buildings & Improvements					0
Costs capitalized subsequent to acquisition					0
Gross amount at which carried at close of period [Abstract]
Land					3,250
Buildings & Improvements					0
Total		3,250			3,250
Accumulated Depreciation		$ 0			0
Date of Construction or Acquisition		2013
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 3,250
Deductions during year [Abstract]
Balance at close of year		0
Unimproved Land [Member] | Bismarck 700 E Main - Bismarck, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					314
Buildings & Improvements					0
Costs capitalized subsequent to acquisition					565
Gross amount at which carried at close of period [Abstract]
Land					879
Buildings & Improvements					0
Total		879			879
Accumulated Depreciation		$ 0			0
Date of Construction or Acquisition		2008
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 879
Deductions during year [Abstract]
Balance at close of year		0
Unimproved Land [Member] | Creekside Crossing - Bismarck, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					4,286
Buildings & Improvements					0
Costs capitalized subsequent to acquisition					0
Gross amount at which carried at close of period [Abstract]
Land					4,286
Buildings & Improvements					0
Total		4,286			4,286
Accumulated Depreciation		$ 0			0
Date of Construction or Acquisition		2014
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 4,286
Deductions during year [Abstract]
Balance at close of year		0
Unimproved Land [Member] | Georgetown Square - Grand Chute, WI [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					1,860
Buildings & Improvements					0
Costs capitalized subsequent to acquisition					0
Gross amount at which carried at close of period [Abstract]
Land					1,860
Buildings & Improvements					0
Total		1,860			1,860
Accumulated Depreciation		$ 0			0
Date of Construction or Acquisition		2006
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 1,860
Deductions during year [Abstract]
Balance at close of year		0
Unimproved Land [Member] | Grand Forks Grand Forks, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					4,278
Buildings & Improvements					0
Costs capitalized subsequent to acquisition					0
Gross amount at which carried at close of period [Abstract]
Land					4,278
Buildings & Improvements					0
Total		4,278			4,278
Accumulated Depreciation		$ 0			0
Date of Construction or Acquisition		2012
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 4,278
Deductions during year [Abstract]
Balance at close of year		0
Unimproved Land [Member] | Isanti Unimproved - Isanti, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					58
Buildings & Improvements					0
Costs capitalized subsequent to acquisition					0
Gross amount at which carried at close of period [Abstract]
Land					58
Buildings & Improvements					0
Total		58			58
Accumulated Depreciation		$ 0			0
Date of Construction or Acquisition		2014
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 58
Deductions during year [Abstract]
Balance at close of year		0
Unimproved Land [Member] | Minot 1525 24th Ave SW - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					1,262
Buildings & Improvements					0
Costs capitalized subsequent to acquisition					0
Gross amount at which carried at close of period [Abstract]
Land					1,262
Buildings & Improvements					0
Total		1,262			1,262
Accumulated Depreciation		$ 0			0
Date of Construction or Acquisition		2014
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 1,262
Deductions during year [Abstract]
Balance at close of year		0
Unimproved Land [Member] | Monticello - Monticello, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					115
Buildings & Improvements					0
Costs capitalized subsequent to acquisition					3
Gross amount at which carried at close of period [Abstract]
Land					118
Buildings & Improvements					0
Total		118			118
Accumulated Depreciation		$ 0			0
Date of Construction or Acquisition		2006
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 118
Deductions during year [Abstract]
Balance at close of year		0
Unimproved Land [Member] | Monticello 7th Addition - Monticello, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					1,734
Buildings & Improvements					0
Costs capitalized subsequent to acquisition					0
Gross amount at which carried at close of period [Abstract]
Land					1,734
Buildings & Improvements					0
Total		1,734			1,734
Accumulated Depreciation		$ 0			0
Date of Construction or Acquisition		2014
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 1,734
Deductions during year [Abstract]
Balance at close of year		0
Unimproved Land [Member] | Rapid City Unimproved- Rapid City, SD [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					1,376
Buildings & Improvements					0
Costs capitalized subsequent to acquisition					0
Gross amount at which carried at close of period [Abstract]
Land					1,376
Buildings & Improvements					0
Total		1,376			1,376
Accumulated Depreciation		$ 0			0
Date of Construction or Acquisition		2014
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 1,376
Deductions during year [Abstract]
Balance at close of year		0
Unimproved Land [Member] | Renaissance Heights - Williston ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					2,229
Buildings & Improvements					0
Costs capitalized subsequent to acquisition					1,581
Gross amount at which carried at close of period [Abstract]
Land					3,810
Buildings & Improvements					0
Total		3,810			3,810
Accumulated Depreciation		$ 0			0
Date of Construction or Acquisition		2012
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 3,810
Deductions during year [Abstract]
Balance at close of year		0
Unimproved Land [Member] | River Falls - River Falls, WI [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					176
Buildings & Improvements					0
Costs capitalized subsequent to acquisition					5
Gross amount at which carried at close of period [Abstract]
Land					181
Buildings & Improvements					0
Total		181			181
Accumulated Depreciation		$ 0			0
Date of Construction or Acquisition		2003
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 181
Deductions during year [Abstract]
Balance at close of year		0
Unimproved Land [Member] | TCA - Eagan, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					325
Buildings & Improvements					0
Costs capitalized subsequent to acquisition					0
Gross amount at which carried at close of period [Abstract]
Land					325
Buildings & Improvements					0
Total		325			325
Accumulated Depreciation		$ 0			0
Date of Construction or Acquisition		2006
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 325
Deductions during year [Abstract]
Balance at close of year		0
Unimproved Land [Member] | Urbandale - Urbandale, IA [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					5
Buildings & Improvements					0
Costs capitalized subsequent to acquisition					109
Gross amount at which carried at close of period [Abstract]
Land					114
Buildings & Improvements					0
Total		114			114
Accumulated Depreciation		$ 0			0
Date of Construction or Acquisition		2009
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 114
Deductions during year [Abstract]
Balance at close of year		0
Unimproved Land [Member] | Weston - Weston, WI [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					370
Buildings & Improvements					0
Costs capitalized subsequent to acquisition					0
Gross amount at which carried at close of period [Abstract]
Land					370
Buildings & Improvements					0
Total		370			370
Accumulated Depreciation		$ 0			0
Date of Construction or Acquisition		2006
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 370
Deductions during year [Abstract]
Balance at close of year		0
Unimproved Land Moved to Development in Progress [Member]
Reconciliations of total real estate carrying value [Abstract]
Transfers		(7,015)	(2,870)	(3,670)
Multi-Family Residential [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				423,385
Initial Cost to Company [Abstract]
Land					65,410
Buildings & Improvements					746,299
Costs capitalized subsequent to acquisition					134,811
Gross amount at which carried at close of period [Abstract]
Land					81,919
Buildings & Improvements					864,601
Total		946,520			946,520
Accumulated Depreciation		(180,414)			(180,414)
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		946,520
Deductions during year [Abstract]
Balance at close of year		180,414
Multi-Family Residential [Member] | 11th Street 3 Plex - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				84
Initial Cost to Company [Abstract]
Land					11
Buildings & Improvements					53
Costs capitalized subsequent to acquisition					19
Gross amount at which carried at close of period [Abstract]
Land					20
Buildings & Improvements					63
Total		83			83
Accumulated Depreciation		$ (12)			(12)
Date of Construction or Acquisition		2008
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 83
Deductions during year [Abstract]
Balance at close of year		12
Multi-Family Residential [Member] | 4th Street 4 Plex - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				98
Initial Cost to Company [Abstract]
Land					15
Buildings & Improvements					74
Costs capitalized subsequent to acquisition					34
Gross amount at which carried at close of period [Abstract]
Land					23
Buildings & Improvements					100
Total		123			123
Accumulated Depreciation		$ (19)			(19)
Date of Construction or Acquisition		2008
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 123
Deductions during year [Abstract]
Balance at close of year		19
Multi-Family Residential [Member] | Alps Park - Rapid City, SD [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				3,934
Initial Cost to Company [Abstract]
Land					287
Buildings & Improvements					5,551
Costs capitalized subsequent to acquisition					165
Gross amount at which carried at close of period [Abstract]
Land					293
Buildings & Improvements					5,710
Total		6,003			6,003
Accumulated Depreciation		$ (299)			(299)
Date of Construction or Acquisition		2013
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 6,003
Deductions during year [Abstract]
Balance at close of year		299
Multi-Family Residential [Member] | Apartments on Main - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				642
Initial Cost to Company [Abstract]
Land					158
Buildings & Improvements					1,123
Costs capitalized subsequent to acquisition					53
Gross amount at which carried at close of period [Abstract]
Land					193
Buildings & Improvements					1,141
Total		1,334			1,334
Accumulated Depreciation		$ (235)			(235)
Date of Construction or Acquisition		1987
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 1,334
Deductions during year [Abstract]
Balance at close of year		$ 235
Multi-Family Residential [Member] | Apartments on Main - Minot, ND [Member] | Minimum [Member]
Gross amount at which carried at close of period [Abstract]
Life on which depreciation in latest income statement is computed		24 years
Multi-Family Residential [Member] | Apartments on Main - Minot, ND [Member] | Maximum [Member]
Gross amount at which carried at close of period [Abstract]
Life on which depreciation in latest income statement is computed		40 years
Multi-Family Residential [Member] | Arbors - S Sioux City, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				3,840
Initial Cost to Company [Abstract]
Land					350
Buildings & Improvements					6,625
Costs capitalized subsequent to acquisition					1,923
Gross amount at which carried at close of period [Abstract]
Land					980
Buildings & Improvements					7,918
Total		$ 8,898			8,898
Accumulated Depreciation		$ (2,115)			(2,115)
Date of Construction or Acquisition		2006
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 8,898
Deductions during year [Abstract]
Balance at close of year		2,115
Multi-Family Residential [Member] | Arcata - Golden Valley, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					2,088
Buildings & Improvements					29,640
Costs capitalized subsequent to acquisition					95
Gross amount at which carried at close of period [Abstract]
Land					2,088
Buildings & Improvements					29,735
Total		31,823			31,823
Accumulated Depreciation		$ (380)			(380)
Date of Construction or Acquisition		2013
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 31,823
Deductions during year [Abstract]
Balance at close of year		380
Multi-Family Residential [Member] | Ashland - Grand Forks, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				5,517
Initial Cost to Company [Abstract]
Land					741
Buildings & Improvements					7,569
Costs capitalized subsequent to acquisition					163
Gross amount at which carried at close of period [Abstract]
Land					774
Buildings & Improvements					7,699
Total		8,473			8,473
Accumulated Depreciation		$ (678)			(678)
Date of Construction or Acquisition		2012
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 8,473
Deductions during year [Abstract]
Balance at close of year		678
Multi-Family Residential [Member] | Boulder Court - Eagan, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				2,736
Initial Cost to Company [Abstract]
Land					1,067
Buildings & Improvements					5,498
Costs capitalized subsequent to acquisition					3,005
Gross amount at which carried at close of period [Abstract]
Land					1,324
Buildings & Improvements					8,246
Total		9,570			9,570
Accumulated Depreciation		$ (2,539)			(2,539)
Date of Construction or Acquisition		2003
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 9,570
Deductions during year [Abstract]
Balance at close of year		2,539
Multi-Family Residential [Member] | Brookfield Village - Topeka, KS [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				5,216
Initial Cost to Company [Abstract]
Land					509
Buildings & Improvements					6,698
Costs capitalized subsequent to acquisition					1,539
Gross amount at which carried at close of period [Abstract]
Land					756
Buildings & Improvements					7,990
Total		8,746			8,746
Accumulated Depreciation		$ (2,348)			(2,348)
Date of Construction or Acquisition		2003
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 8,746
Deductions during year [Abstract]
Balance at close of year		2,348
Multi-Family Residential [Member] | Brooklyn Heights - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				694
Initial Cost to Company [Abstract]
Land					145
Buildings & Improvements					1,450
Costs capitalized subsequent to acquisition					879
Gross amount at which carried at close of period [Abstract]
Land					219
Buildings & Improvements					2,255
Total		2,474			2,474
Accumulated Depreciation		$ (949)			(949)
Date of Construction or Acquisition		1997
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 2,474
Deductions during year [Abstract]
Balance at close of year		$ 949
Multi-Family Residential [Member] | Brooklyn Heights - Minot, ND [Member] | Minimum [Member]
Gross amount at which carried at close of period [Abstract]
Life on which depreciation in latest income statement is computed		12 years
Multi-Family Residential [Member] | Brooklyn Heights - Minot, ND [Member] | Maximum [Member]
Gross amount at which carried at close of period [Abstract]
Life on which depreciation in latest income statement is computed		40 years
Multi-Family Residential [Member] | Campus Center - St. Cloud, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				1,127
Initial Cost to Company [Abstract]
Land					395
Buildings & Improvements					2,244
Costs capitalized subsequent to acquisition					243
Gross amount at which carried at close of period [Abstract]
Land					407
Buildings & Improvements					2,475
Total		$ 2,882			2,882
Accumulated Depreciation		$ (534)			(534)
Date of Construction or Acquisition		2007
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 2,882
Deductions during year [Abstract]
Balance at close of year		534
Multi-Family Residential [Member] | Campus Heights - St. Cloud, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					110
Buildings & Improvements					628
Costs capitalized subsequent to acquisition					157
Gross amount at which carried at close of period [Abstract]
Land					124
Buildings & Improvements					771
Total		895			895
Accumulated Depreciation		$ (163)			(163)
Date of Construction or Acquisition		2007
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 895
Deductions during year [Abstract]
Balance at close of year		163
Multi-Family Residential [Member] | Campus Knoll - St. Cloud, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				752
Initial Cost to Company [Abstract]
Land					266
Buildings & Improvements					1,512
Costs capitalized subsequent to acquisition					180
Gross amount at which carried at close of period [Abstract]
Land					305
Buildings & Improvements					1,653
Total		1,958			1,958
Accumulated Depreciation		$ (364)			(364)
Date of Construction or Acquisition		2007
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 1,958
Deductions during year [Abstract]
Balance at close of year		364
Multi-Family Residential [Member] | Campus Plaza - St. Cloud, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					54
Buildings & Improvements					311
Costs capitalized subsequent to acquisition					85
Gross amount at which carried at close of period [Abstract]
Land					60
Buildings & Improvements					390
Total		450			450
Accumulated Depreciation		$ (87)			(87)
Date of Construction or Acquisition		2007
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 450
Deductions during year [Abstract]
Balance at close of year		87
Multi-Family Residential [Member] | Campus Side - St. Cloud, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					107
Buildings & Improvements					615
Costs capitalized subsequent to acquisition					161
Gross amount at which carried at close of period [Abstract]
Land					118
Buildings & Improvements					765
Total		883			883
Accumulated Depreciation		$ (170)			(170)
Date of Construction or Acquisition		2007
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 883
Deductions during year [Abstract]
Balance at close of year		170
Multi-Family Residential [Member] | Campus View - St. Cloud, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					107
Buildings & Improvements					615
Costs capitalized subsequent to acquisition					156
Gross amount at which carried at close of period [Abstract]
Land					113
Buildings & Improvements					765
Total		878			878
Accumulated Depreciation		$ (164)			(164)
Date of Construction or Acquisition		2007
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 878
Deductions during year [Abstract]
Balance at close of year		164
Multi-Family Residential [Member] | Canyon Lake - Rapid City, SD [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				2,843
Initial Cost to Company [Abstract]
Land					305
Buildings & Improvements					3,958
Costs capitalized subsequent to acquisition					1,652
Gross amount at which carried at close of period [Abstract]
Land					376
Buildings & Improvements					5,539
Total		5,915			5,915
Accumulated Depreciation		$ (1,739)			(1,739)
Date of Construction or Acquisition		2001
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 5,915
Deductions during year [Abstract]
Balance at close of year		1,739
Multi-Family Residential [Member] | Castlerock - Billings, MT [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				6,574
Initial Cost to Company [Abstract]
Land					736
Buildings & Improvements					4,864
Costs capitalized subsequent to acquisition					2,165
Gross amount at which carried at close of period [Abstract]
Land					994
Buildings & Improvements					6,771
Total		7,765			7,765
Accumulated Depreciation		$ (2,726)			(2,726)
Date of Construction or Acquisition		1998
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 7,765
Deductions during year [Abstract]
Balance at close of year		2,726
Multi-Family Residential [Member] | Chateau I - Minot ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					61
Buildings & Improvements					5,663
Costs capitalized subsequent to acquisition					683
Gross amount at which carried at close of period [Abstract]
Land					71
Buildings & Improvements					6,336
Total		6,407			6,407
Accumulated Depreciation		$ (786)			(786)
Date of Construction or Acquisition		2013
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 6,407
Deductions during year [Abstract]
Balance at close of year		786
Multi-Family Residential [Member] | Cimarron Hills - Omaha, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				4,729
Initial Cost to Company [Abstract]
Land					706
Buildings & Improvements					9,588
Costs capitalized subsequent to acquisition					4,346
Gross amount at which carried at close of period [Abstract]
Land					1,334
Buildings & Improvements					13,306
Total		14,640			14,640
Accumulated Depreciation		$ (4,723)			(4,723)
Date of Construction or Acquisition		2001
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 14,640
Deductions during year [Abstract]
Balance at close of year		4,723
Multi-Family Residential [Member] | Colonial Villa - Burnsville, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				5,473
Initial Cost to Company [Abstract]
Land					2,401
Buildings & Improvements					11,515
Costs capitalized subsequent to acquisition					7,471
Gross amount at which carried at close of period [Abstract]
Land					2,844
Buildings & Improvements					18,543
Total		21,387			21,387
Accumulated Depreciation		$ (5,255)			(5,255)
Date of Construction or Acquisition		2003
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 21,387
Deductions during year [Abstract]
Balance at close of year		5,255
Multi-Family Residential [Member] | Colony - Lincoln, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				13,303
Initial Cost to Company [Abstract]
Land					1,515
Buildings & Improvements					15,730
Costs capitalized subsequent to acquisition					671
Gross amount at which carried at close of period [Abstract]
Land					1,574
Buildings & Improvements					16,342
Total		17,916			17,916
Accumulated Depreciation		$ (1,316)			(1,316)
Date of Construction or Acquisition		2012
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 17,916
Deductions during year [Abstract]
Balance at close of year		1,316
Multi-Family Residential [Member] | Colton Heights - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				391
Initial Cost to Company [Abstract]
Land					80
Buildings & Improvements					672
Costs capitalized subsequent to acquisition					421
Gross amount at which carried at close of period [Abstract]
Land					123
Buildings & Improvements					1,050
Total		1,173			1,173
Accumulated Depreciation		$ (769)			(769)
Date of Construction or Acquisition		1984
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 1,173
Deductions during year [Abstract]
Balance at close of year		769
Multi-Family Residential [Member] | Commons at Southgate - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					3,691
Buildings & Improvements					31,351
Costs capitalized subsequent to acquisition					580
Gross amount at which carried at close of period [Abstract]
Land					3,703
Buildings & Improvements					31,919
Total		35,622			35,622
Accumulated Depreciation		$ (993)			(993)
Date of Construction or Acquisition		2013
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 35,622
Deductions during year [Abstract]
Balance at close of year		993
Multi-Family Residential [Member] | Cornerstone - St. Cloud, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					54
Buildings & Improvements					311
Costs capitalized subsequent to acquisition					88
Gross amount at which carried at close of period [Abstract]
Land					57
Buildings & Improvements					396
Total		453			453
Accumulated Depreciation		$ (89)			(89)
Date of Construction or Acquisition		2007
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 453
Deductions during year [Abstract]
Balance at close of year		89
Multi-Family Residential [Member] | Cottage West Twin Homes - Sioux Falls, SD [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				3,586
Initial Cost to Company [Abstract]
Land					968
Buildings & Improvements					3,762
Costs capitalized subsequent to acquisition					432
Gross amount at which carried at close of period [Abstract]
Land					1,022
Buildings & Improvements					4,140
Total		5,162			5,162
Accumulated Depreciation		$ (378)			(378)
Date of Construction or Acquisition		2011
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 5,162
Deductions during year [Abstract]
Balance at close of year		378
Multi-Family Residential [Member] | Cottonwood - Bismarck, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				15,586
Initial Cost to Company [Abstract]
Land					1,056
Buildings & Improvements					17,372
Costs capitalized subsequent to acquisition					3,294
Gross amount at which carried at close of period [Abstract]
Land					1,383
Buildings & Improvements					20,339
Total		21,722			21,722
Accumulated Depreciation		$ (6,904)			(6,904)
Date of Construction or Acquisition		1997
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 21,722
Deductions during year [Abstract]
Balance at close of year		6,904
Multi-Family Residential [Member] | Country Meadows - Billings, MT [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				6,560
Initial Cost to Company [Abstract]
Land					491
Buildings & Improvements					7,809
Costs capitalized subsequent to acquisition					1,486
Gross amount at which carried at close of period [Abstract]
Land					538
Buildings & Improvements					9,248
Total		9,786			9,786
Accumulated Depreciation		$ (3,797)			(3,797)
Date of Construction or Acquisition		1995
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 9,786
Deductions during year [Abstract]
Balance at close of year		$ 3,797
Multi-Family Residential [Member] | Country Meadows - Billings, MT [Member] | Minimum [Member]
Gross amount at which carried at close of period [Abstract]
Life on which depreciation in latest income statement is computed		33 years
Multi-Family Residential [Member] | Country Meadows - Billings, MT [Member] | Maximum [Member]
Gross amount at which carried at close of period [Abstract]
Life on which depreciation in latest income statement is computed		40 years
Multi-Family Residential [Member] | Crestview - Bismarck, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				3,839
Initial Cost to Company [Abstract]
Land					235
Buildings & Improvements					4,290
Costs capitalized subsequent to acquisition					1,682
Gross amount at which carried at close of period [Abstract]
Land					515
Buildings & Improvements					5,692
Total		$ 6,207			6,207
Accumulated Depreciation		$ (2,915)			(2,915)
Date of Construction or Acquisition		1994
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 6,207
Deductions during year [Abstract]
Balance at close of year		$ 2,915
Multi-Family Residential [Member] | Crestview - Bismarck, ND [Member] | Minimum [Member]
Gross amount at which carried at close of period [Abstract]
Life on which depreciation in latest income statement is computed		24 years
Multi-Family Residential [Member] | Crestview - Bismarck, ND [Member] | Maximum [Member]
Gross amount at which carried at close of period [Abstract]
Life on which depreciation in latest income statement is computed		40 years
Multi-Family Residential [Member] | Crown - Rochester, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				2,571
Initial Cost to Company [Abstract]
Land					261
Buildings & Improvements					3,289
Costs capitalized subsequent to acquisition					246
Gross amount at which carried at close of period [Abstract]
Land					269
Buildings & Improvements					3,527
Total		$ 3,796			3,796
Accumulated Depreciation		$ (470)			(470)
Date of Construction or Acquisition		2010
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 3,796
Deductions during year [Abstract]
Balance at close of year		470
Multi-Family Residential [Member] | Crown Colony - Topeka, KS [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				8,081
Initial Cost to Company [Abstract]
Land					620
Buildings & Improvements					9,956
Costs capitalized subsequent to acquisition					2,388
Gross amount at which carried at close of period [Abstract]
Land					898
Buildings & Improvements					12,066
Total		12,964			12,964
Accumulated Depreciation		$ (4,531)			(4,531)
Date of Construction or Acquisition		1999
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 12,964
Deductions during year [Abstract]
Balance at close of year		4,531
Multi-Family Residential [Member] | Cypress Court - St. Cloud, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				13,150
Initial Cost to Company [Abstract]
Land					1,583
Buildings & Improvements					18,874
Costs capitalized subsequent to acquisition					148
Gross amount at which carried at close of period [Abstract]
Land					1,583
Buildings & Improvements					19,022
Total		20,605			20,605
Accumulated Depreciation		$ (652)			(652)
Date of Construction or Acquisition		2012
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 20,605
Deductions during year [Abstract]
Balance at close of year		652
Multi-Family Residential [Member] | Dakota Commons - Williston, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1],[6]				0
Initial Cost to Company [Abstract]
Land	[6]				823
Buildings & Improvements	[6]				9,596
Costs capitalized subsequent to acquisition	[6]				25
Gross amount at which carried at close of period [Abstract]
Land	[6]				824
Buildings & Improvements	[6]				9,620
Total	[6]	10,444			10,444
Accumulated Depreciation	[6]	$ (236)			(236)
Date of Construction or Acquisition	[6]	2012
Life on which depreciation in latest income statement is computed	[6]	40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year	[6]	$ 10,444
Deductions during year [Abstract]
Balance at close of year	[6]	236
Multi-Family Residential [Member] | Evergreen - Isanti, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				1,986
Initial Cost to Company [Abstract]
Land					380
Buildings & Improvements					2,740
Costs capitalized subsequent to acquisition					116
Gross amount at which carried at close of period [Abstract]
Land					385
Buildings & Improvements					2,851
Total		3,236			3,236
Accumulated Depreciation		$ (474)			(474)
Date of Construction or Acquisition		2008
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 3,236
Deductions during year [Abstract]
Balance at close of year		474
Multi-Family Residential [Member] | Evergreen II - Isanti, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				2,066
Initial Cost to Company [Abstract]
Land					691
Buildings & Improvements					2,784
Costs capitalized subsequent to acquisition					55
Gross amount at which carried at close of period [Abstract]
Land					698
Buildings & Improvements					2,832
Total		3,530			3,530
Accumulated Depreciation		$ (277)			(277)
Date of Construction or Acquisition		2011
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 3,530
Deductions during year [Abstract]
Balance at close of year		277
Multi-Family Residential [Member] | Fairmont - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				332
Initial Cost to Company [Abstract]
Land					28
Buildings & Improvements					337
Costs capitalized subsequent to acquisition					117
Gross amount at which carried at close of period [Abstract]
Land					55
Buildings & Improvements					427
Total		482			482
Accumulated Depreciation		$ (76)			(76)
Date of Construction or Acquisition		2008
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 482
Deductions during year [Abstract]
Balance at close of year		76
Multi-Family Residential [Member] | First Avenue - Minot ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					0
Buildings & Improvements					3,046
Costs capitalized subsequent to acquisition					11
Gross amount at which carried at close of period [Abstract]
Land					0
Buildings & Improvements					3,057
Total		3,057			3,057
Accumulated Depreciation		$ (155)			(155)
Date of Construction or Acquisition		2013
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 3,057
Deductions during year [Abstract]
Balance at close of year		155
Multi-Family Residential [Member] | Forest Park - Grand Forks, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				7,560
Initial Cost to Company [Abstract]
Land					810
Buildings & Improvements					5,579
Costs capitalized subsequent to acquisition					7,407
Gross amount at which carried at close of period [Abstract]
Land					1,426
Buildings & Improvements					12,370
Total		13,796			13,796
Accumulated Depreciation		$ (5,333)			(5,333)
Date of Construction or Acquisition		1993
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 13,796
Deductions during year [Abstract]
Balance at close of year		$ 5,333
Multi-Family Residential [Member] | Forest Park - Grand Forks, ND [Member] | Minimum [Member]
Gross amount at which carried at close of period [Abstract]
Life on which depreciation in latest income statement is computed		24 years
Multi-Family Residential [Member] | Forest Park - Grand Forks, ND [Member] | Maximum [Member]
Gross amount at which carried at close of period [Abstract]
Life on which depreciation in latest income statement is computed		40 years
Multi-Family Residential [Member] | Gables Townhomes - Sioux Falls, SD [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				1,452
Initial Cost to Company [Abstract]
Land					349
Buildings & Improvements					1,921
Costs capitalized subsequent to acquisition					173
Gross amount at which carried at close of period [Abstract]
Land					374
Buildings & Improvements					2,069
Total		$ 2,443			2,443
Accumulated Depreciation		$ (189)			(189)
Date of Construction or Acquisition		2011
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 2,443
Deductions during year [Abstract]
Balance at close of year		189
Multi-Family Residential [Member] | Grand Gateway - St. Cloud, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				5,345
Initial Cost to Company [Abstract]
Land					814
Buildings & Improvements					7,086
Costs capitalized subsequent to acquisition					805
Gross amount at which carried at close of period [Abstract]
Land					934
Buildings & Improvements					7,771
Total		8,705			8,705
Accumulated Depreciation		$ (746)			(746)
Date of Construction or Acquisition		2012
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 8,705
Deductions during year [Abstract]
Balance at close of year		746
Multi-Family Residential [Member] | Greenfield - Omaha, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				3,552
Initial Cost to Company [Abstract]
Land					578
Buildings & Improvements					4,122
Costs capitalized subsequent to acquisition					769
Gross amount at which carried at close of period [Abstract]
Land					803
Buildings & Improvements					4,666
Total		5,469			5,469
Accumulated Depreciation		$ (932)			(932)
Date of Construction or Acquisition		2007
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 5,469
Deductions during year [Abstract]
Balance at close of year		932
Multi-Family Residential [Member] | Heritage Manor - Rochester, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				3,895
Initial Cost to Company [Abstract]
Land					403
Buildings & Improvements					6,968
Costs capitalized subsequent to acquisition					2,796
Gross amount at which carried at close of period [Abstract]
Land					580
Buildings & Improvements					9,587
Total		10,167			10,167
Accumulated Depreciation		$ (3,751)			(3,751)
Date of Construction or Acquisition		1998
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 10,167
Deductions during year [Abstract]
Balance at close of year		3,751
Multi-Family Residential [Member] | Homestead Garden - Rapid City, SD [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				9,761
Initial Cost to Company [Abstract]
Land					655
Buildings & Improvements					14,139
Costs capitalized subsequent to acquisition					156
Gross amount at which carried at close of period [Abstract]
Land					658
Buildings & Improvements					14,292
Total		14,950			14,950
Accumulated Depreciation		$ (329)			(329)
Date of Construction or Acquisition		2014
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 14,950
Deductions during year [Abstract]
Balance at close of year		329
Multi-Family Residential [Member] | Indian Hills - Sioux City, IA [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					294
Buildings & Improvements					2,921
Costs capitalized subsequent to acquisition					3,709
Gross amount at which carried at close of period [Abstract]
Land					397
Buildings & Improvements					6,527
Total		6,924			6,924
Accumulated Depreciation		$ (1,353)			(1,353)
Date of Construction or Acquisition		2007
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 6,924
Deductions during year [Abstract]
Balance at close of year		1,353
Multi-Family Residential [Member] | Kirkwood Manor - Bismarck, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				3,259
Initial Cost to Company [Abstract]
Land					449
Buildings & Improvements					2,725
Costs capitalized subsequent to acquisition					1,676
Gross amount at which carried at close of period [Abstract]
Land					553
Buildings & Improvements					4,297
Total		4,850			4,850
Accumulated Depreciation		$ (1,786)			(1,786)
Date of Construction or Acquisition		1997
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 4,850
Deductions during year [Abstract]
Balance at close of year		$ 1,786
Multi-Family Residential [Member] | Kirkwood Manor - Bismarck, ND [Member] | Minimum [Member]
Gross amount at which carried at close of period [Abstract]
Life on which depreciation in latest income statement is computed		12 years
Multi-Family Residential [Member] | Kirkwood Manor - Bismarck, ND [Member] | Maximum [Member]
Gross amount at which carried at close of period [Abstract]
Life on which depreciation in latest income statement is computed		40 years
Multi-Family Residential [Member] | Lakeside Village Lincoln, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				13,129
Initial Cost to Company [Abstract]
Land					1,215
Buildings & Improvements					15,837
Costs capitalized subsequent to acquisition					442
Gross amount at which carried at close of period [Abstract]
Land					1,263
Buildings & Improvements					16,231
Total		$ 17,494			17,494
Accumulated Depreciation		$ (1,294)			(1,294)
Date of Construction or Acquisition		2012
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 17,494
Deductions during year [Abstract]
Balance at close of year		1,294
Multi-Family Residential [Member] | Landing at Southgate - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					2,254
Buildings & Improvements					12,955
Costs capitalized subsequent to acquisition					93
Gross amount at which carried at close of period [Abstract]
Land					2,294
Buildings & Improvements					13,008
Total		15,302			15,302
Accumulated Depreciation		$ (546)			(546)
Date of Construction or Acquisition		2013
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 15,302
Deductions during year [Abstract]
Balance at close of year		546
Multi-Family Residential [Member] | Landmark - Grand Forks, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				1,573
Initial Cost to Company [Abstract]
Land					184
Buildings & Improvements					1,514
Costs capitalized subsequent to acquisition					1,093
Gross amount at which carried at close of period [Abstract]
Land					331
Buildings & Improvements					2,460
Total		2,791			2,791
Accumulated Depreciation		$ (1,070)			(1,070)
Date of Construction or Acquisition		1997
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 2,791
Deductions during year [Abstract]
Balance at close of year		1,070
Multi-Family Residential [Member] | Legacy - Grand Forks, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				15,528
Initial Cost to Company [Abstract]
Land					1,362
Buildings & Improvements					21,727
Costs capitalized subsequent to acquisition					6,665
Gross amount at which carried at close of period [Abstract]
Land					2,133
Buildings & Improvements					27,621
Total		29,754			29,754
Accumulated Depreciation		(10,186)			(10,186)
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		29,754
Deductions during year [Abstract]
Balance at close of year		$ 10,186
Multi-Family Residential [Member] | Legacy - Grand Forks, ND [Member] | Minimum [Member]
Gross amount at which carried at close of period [Abstract]
Date of Construction or Acquisition		1995
Life on which depreciation in latest income statement is computed		24 years
Multi-Family Residential [Member] | Legacy - Grand Forks, ND [Member] | Maximum [Member]
Gross amount at which carried at close of period [Abstract]
Date of Construction or Acquisition		2005
Life on which depreciation in latest income statement is computed		40 years
Multi-Family Residential [Member] | Legacy Heights - Bismarck, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					804
Buildings & Improvements					9,162
Costs capitalized subsequent to acquisition					73
Gross amount at which carried at close of period [Abstract]
Land					804
Buildings & Improvements					9,235
Total		$ 10,039			10,039
Accumulated Depreciation		$ (21)			(21)
Date of Construction or Acquisition		2015
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 10,039
Deductions during year [Abstract]
Balance at close of year		21
Multi-Family Residential [Member] | Mariposa - Topeka, KS [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				2,925
Initial Cost to Company [Abstract]
Land					399
Buildings & Improvements					5,110
Costs capitalized subsequent to acquisition					535
Gross amount at which carried at close of period [Abstract]
Land					427
Buildings & Improvements					5,617
Total		6,044			6,044
Accumulated Depreciation		$ (1,498)			(1,498)
Date of Construction or Acquisition		2004
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 6,044
Deductions during year [Abstract]
Balance at close of year		1,498
Multi-Family Residential [Member] | Meadows - Jamestown, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1],[6]				0
Initial Cost to Company [Abstract]
Land	[6]				590
Buildings & Improvements	[6]				4,519
Costs capitalized subsequent to acquisition	[6]				1,355
Gross amount at which carried at close of period [Abstract]
Land	[6]				669
Buildings & Improvements	[6]				5,795
Total	[6]	6,464			6,464
Accumulated Depreciation	[6]	$ (2,135)			(2,135)
Date of Construction or Acquisition	[6]	1998
Life on which depreciation in latest income statement is computed	[6]	40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year	[6]	$ 6,464
Deductions during year [Abstract]
Balance at close of year	[6]	2,135
Multi-Family Residential [Member] | Monticello Village - Monticello, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				2,956
Initial Cost to Company [Abstract]
Land					490
Buildings & Improvements					3,756
Costs capitalized subsequent to acquisition					491
Gross amount at which carried at close of period [Abstract]
Land					621
Buildings & Improvements					4,116
Total		4,737			4,737
Accumulated Depreciation		$ (1,257)			(1,257)
Date of Construction or Acquisition		2004
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 4,737
Deductions during year [Abstract]
Balance at close of year		1,257
Multi-Family Residential [Member] | Northern Valley - Rochester, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					110
Buildings & Improvements					610
Costs capitalized subsequent to acquisition					129
Gross amount at which carried at close of period [Abstract]
Land					119
Buildings & Improvements					730
Total		849			849
Accumulated Depreciation		$ (100)			(100)
Date of Construction or Acquisition		2010
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 849
Deductions during year [Abstract]
Balance at close of year		100
Multi-Family Residential [Member] | North Pointe - Bismarck, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				3,382
Initial Cost to Company [Abstract]
Land					303
Buildings & Improvements					3,957
Costs capitalized subsequent to acquisition					622
Gross amount at which carried at close of period [Abstract]
Land					354
Buildings & Improvements					4,528
Total		4,882			4,882
Accumulated Depreciation		(1,474)			(1,474)
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		4,882
Deductions during year [Abstract]
Balance at close of year		$ 1,474
Multi-Family Residential [Member] | North Pointe - Bismarck, ND [Member] | Minimum [Member]
Gross amount at which carried at close of period [Abstract]
Date of Construction or Acquisition		1995
Life on which depreciation in latest income statement is computed		24 years
Multi-Family Residential [Member] | North Pointe - Bismarck, ND [Member] | Maximum [Member]
Gross amount at which carried at close of period [Abstract]
Date of Construction or Acquisition		2011
Life on which depreciation in latest income statement is computed		40 years
Multi-Family Residential [Member] | Northridge - Bismarck, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				6,322
Initial Cost to Company [Abstract]
Land					884
Buildings & Improvements					7,516
Costs capitalized subsequent to acquisition					26
Gross amount at which carried at close of period [Abstract]
Land					888
Buildings & Improvements					7,538
Total		$ 8,426			8,426
Accumulated Depreciation		$ (126)			(126)
Date of Construction or Acquisition		2014
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 8,426
Deductions during year [Abstract]
Balance at close of year		126
Multi-Family Residential [Member] | Oakmont Estates - Sioux Falls, SD [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				2,418
Initial Cost to Company [Abstract]
Land					422
Buildings & Improvements					4,838
Costs capitalized subsequent to acquisition					638
Gross amount at which carried at close of period [Abstract]
Land					627
Buildings & Improvements					5,271
Total		5,898			5,898
Accumulated Depreciation		$ (1,746)			(1,746)
Date of Construction or Acquisition		2002
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 5,898
Deductions during year [Abstract]
Balance at close of year		1,746
Multi-Family Residential [Member] | Oakwood Estates - Sioux Falls, SD [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				3,939
Initial Cost to Company [Abstract]
Land					543
Buildings & Improvements					2,784
Costs capitalized subsequent to acquisition					4,336
Gross amount at which carried at close of period [Abstract]
Land					777
Buildings & Improvements					6,886
Total		7,663			7,663
Accumulated Depreciation		$ (3,214)			(3,214)
Date of Construction or Acquisition		1993
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 7,663
Deductions during year [Abstract]
Balance at close of year		3,214
Multi-Family Residential [Member] | Olympic Village - Billings, MT [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				10,575
Initial Cost to Company [Abstract]
Land					1,164
Buildings & Improvements					10,441
Costs capitalized subsequent to acquisition					3,086
Gross amount at which carried at close of period [Abstract]
Land					1,785
Buildings & Improvements					12,906
Total		14,691			14,691
Accumulated Depreciation		$ (4,881)			(4,881)
Date of Construction or Acquisition		2000
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 14,691
Deductions during year [Abstract]
Balance at close of year		4,881
Multi-Family Residential [Member] | Olympik Village - Rochester, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				4,382
Initial Cost to Company [Abstract]
Land					1,034
Buildings & Improvements					6,109
Costs capitalized subsequent to acquisition					1,968
Gross amount at which carried at close of period [Abstract]
Land					1,183
Buildings & Improvements					7,928
Total		9,111			9,111
Accumulated Depreciation		$ (2,127)			(2,127)
Date of Construction or Acquisition		2005
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 9,111
Deductions during year [Abstract]
Balance at close of year		2,127
Multi-Family Residential [Member] | Oxbow Park - Sioux Falls, SD [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				3,846
Initial Cost to Company [Abstract]
Land					404
Buildings & Improvements					3,152
Costs capitalized subsequent to acquisition					2,894
Gross amount at which carried at close of period [Abstract]
Land					824
Buildings & Improvements					5,626
Total		6,450			6,450
Accumulated Depreciation		$ (2,808)			(2,808)
Date of Construction or Acquisition		1994
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 6,450
Deductions during year [Abstract]
Balance at close of year		$ 2,808
Multi-Family Residential [Member] | Oxbow Park - Sioux Falls, SD [Member] | Minimum [Member]
Gross amount at which carried at close of period [Abstract]
Life on which depreciation in latest income statement is computed		24 years
Multi-Family Residential [Member] | Oxbow Park - Sioux Falls, SD [Member] | Maximum [Member]
Gross amount at which carried at close of period [Abstract]
Life on which depreciation in latest income statement is computed		40 years
Multi-Family Residential [Member] | Park Meadows - Waite Park, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				8,482
Initial Cost to Company [Abstract]
Land					1,143
Buildings & Improvements					9,099
Costs capitalized subsequent to acquisition					5,792
Gross amount at which carried at close of period [Abstract]
Land					1,629
Buildings & Improvements					14,405
Total		$ 16,034			16,034
Accumulated Depreciation		$ (5,939)			(5,939)
Date of Construction or Acquisition		1997
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 16,034
Deductions during year [Abstract]
Balance at close of year		5,939
Multi-Family Residential [Member] | Pebble Springs - Bismarck, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				757
Initial Cost to Company [Abstract]
Land					7
Buildings & Improvements					748
Costs capitalized subsequent to acquisition					165
Gross amount at which carried at close of period [Abstract]
Land					54
Buildings & Improvements					866
Total		920			920
Accumulated Depreciation		$ (349)			(349)
Date of Construction or Acquisition		1999
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 920
Deductions during year [Abstract]
Balance at close of year		349
Multi-Family Residential [Member] | Pinehurst - Billings, MT [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				205
Initial Cost to Company [Abstract]
Land					72
Buildings & Improvements					687
Costs capitalized subsequent to acquisition					251
Gross amount at which carried at close of period [Abstract]
Land					81
Buildings & Improvements					929
Total		1,010			1,010
Accumulated Depreciation		$ (305)			(305)
Date of Construction or Acquisition		2002
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 1,010
Deductions during year [Abstract]
Balance at close of year		305
Multi-Family Residential [Member] | Pinecone Villas - Sartell, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					584
Buildings & Improvements					2,191
Costs capitalized subsequent to acquisition					27
Gross amount at which carried at close of period [Abstract]
Land					585
Buildings & Improvements					2,217
Total		2,802			2,802
Accumulated Depreciation		$ (95)			(95)
Date of Construction or Acquisition		2013
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 2,802
Deductions during year [Abstract]
Balance at close of year		95
Multi-Family Residential [Member] | Pines - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				111
Initial Cost to Company [Abstract]
Land					35
Buildings & Improvements					215
Costs capitalized subsequent to acquisition					185
Gross amount at which carried at close of period [Abstract]
Land					49
Buildings & Improvements					386
Total		435			435
Accumulated Depreciation		$ (141)			(141)
Date of Construction or Acquisition		1997
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 435
Deductions during year [Abstract]
Balance at close of year		141
Multi-Family Residential [Member] | Plaza - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				5,348
Initial Cost to Company [Abstract]
Land					867
Buildings & Improvements					12,784
Costs capitalized subsequent to acquisition					2,455
Gross amount at which carried at close of period [Abstract]
Land					995
Buildings & Improvements					15,111
Total		16,106			16,106
Accumulated Depreciation		$ (2,433)			(2,433)
Date of Construction or Acquisition		2009
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 16,106
Deductions during year [Abstract]
Balance at close of year		2,433
Multi-Family Residential [Member] | Pointe West - Rapid City, SD [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				2,624
Initial Cost to Company [Abstract]
Land					240
Buildings & Improvements					3,538
Costs capitalized subsequent to acquisition					1,527
Gross amount at which carried at close of period [Abstract]
Land					368
Buildings & Improvements					4,937
Total		5,305			5,305
Accumulated Depreciation		$ (2,379)			(2,379)
Date of Construction or Acquisition		1994
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 5,305
Deductions during year [Abstract]
Balance at close of year		$ 2,379
Multi-Family Residential [Member] | Pointe West - Rapid City, SD [Member] | Minimum [Member]
Gross amount at which carried at close of period [Abstract]
Life on which depreciation in latest income statement is computed		24 years
Multi-Family Residential [Member] | Pointe West - Rapid City, SD [Member] | Maximum [Member]
Gross amount at which carried at close of period [Abstract]
Life on which depreciation in latest income statement is computed		40 years
Multi-Family Residential [Member] | Ponds at Heritage Place - Sartell, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				3,852
Initial Cost to Company [Abstract]
Land					395
Buildings & Improvements					4,564
Costs capitalized subsequent to acquisition					320
Gross amount at which carried at close of period [Abstract]
Land					404
Buildings & Improvements					4,875
Total		$ 5,279			5,279
Accumulated Depreciation		$ (363)			(363)
Date of Construction or Acquisition		2012
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 5,279
Deductions during year [Abstract]
Balance at close of year		363
Multi-Family Residential [Member] | Prairie Winds - Sioux Falls, SD [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				1,410
Initial Cost to Company [Abstract]
Land					144
Buildings & Improvements					1,816
Costs capitalized subsequent to acquisition					487
Gross amount at which carried at close of period [Abstract]
Land					235
Buildings & Improvements					2,212
Total		2,447			2,447
Accumulated Depreciation		$ (1,228)			(1,228)
Date of Construction or Acquisition		1993
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 2,447
Deductions during year [Abstract]
Balance at close of year		$ 1,228
Multi-Family Residential [Member] | Prairie Winds - Sioux Falls, SD [Member] | Minimum [Member]
Gross amount at which carried at close of period [Abstract]
Life on which depreciation in latest income statement is computed		24 years
Multi-Family Residential [Member] | Prairie Winds - Sioux Falls, SD [Member] | Maximum [Member]
Gross amount at which carried at close of period [Abstract]
Life on which depreciation in latest income statement is computed		40 years
Multi-Family Residential [Member] | Quarry Ridge - Rochester, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				27,268
Initial Cost to Company [Abstract]
Land					2,254
Buildings & Improvements					30,024
Costs capitalized subsequent to acquisition					1,392
Gross amount at which carried at close of period [Abstract]
Land					2,307
Buildings & Improvements					31,363
Total		$ 33,670			33,670
Accumulated Depreciation		$ (4,533)			(4,533)
Date of Construction or Acquisition		2006
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 33,670
Deductions during year [Abstract]
Balance at close of year		4,533
Multi-Family Residential [Member] | RED 20 - Minneapolis, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					1,900
Buildings & Improvements					26,412
Costs capitalized subsequent to acquisition					4
Gross amount at which carried at close of period [Abstract]
Land					1,900
Buildings & Improvements					26,416
Total		28,316			28,316
Accumulated Depreciation		$ (445)			(445)
Date of Construction or Acquisition		2013
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 28,316
Deductions during year [Abstract]
Balance at close of year		445
Multi-Family Residential [Member] | Regency Park Estates - St. Cloud, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				6,680
Initial Cost to Company [Abstract]
Land					702
Buildings & Improvements					10,198
Costs capitalized subsequent to acquisition					1,465
Gross amount at which carried at close of period [Abstract]
Land					811
Buildings & Improvements					11,554
Total		12,365			12,365
Accumulated Depreciation		$ (1,162)			(1,162)
Date of Construction or Acquisition		2011
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 12,365
Deductions during year [Abstract]
Balance at close of year		1,162
Multi-Family Residential [Member] | Ridge Oaks - Sioux City, IA [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				3,359
Initial Cost to Company [Abstract]
Land					178
Buildings & Improvements					4,073
Costs capitalized subsequent to acquisition					2,437
Gross amount at which carried at close of period [Abstract]
Land					288
Buildings & Improvements					6,400
Total		6,688			6,688
Accumulated Depreciation		$ (2,205)			(2,205)
Date of Construction or Acquisition		2001
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 6,688
Deductions during year [Abstract]
Balance at close of year		2,205
Multi-Family Residential [Member] | Rimrock West - Billings, MT [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				3,282
Initial Cost to Company [Abstract]
Land					330
Buildings & Improvements					3,489
Costs capitalized subsequent to acquisition					1,510
Gross amount at which carried at close of period [Abstract]
Land					435
Buildings & Improvements					4,894
Total		5,329			5,329
Accumulated Depreciation		$ (1,765)			(1,765)
Date of Construction or Acquisition		1999
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 5,329
Deductions during year [Abstract]
Balance at close of year		1,765
Multi-Family Residential [Member] | River Ridge - Bismarck, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				13,200
Initial Cost to Company [Abstract]
Land					576
Buildings & Improvements					23,826
Costs capitalized subsequent to acquisition					998
Gross amount at which carried at close of period [Abstract]
Land					1,438
Buildings & Improvements					23,962
Total		25,400			25,400
Accumulated Depreciation		$ (1,290)			(1,290)
Date of Construction or Acquisition		2008
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 25,400
Deductions during year [Abstract]
Balance at close of year		1,290
Multi-Family Residential [Member] | Rocky Meadows - Billings, MT [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				5,089
Initial Cost to Company [Abstract]
Land					656
Buildings & Improvements					5,726
Costs capitalized subsequent to acquisition					1,201
Gross amount at which carried at close of period [Abstract]
Land					772
Buildings & Improvements					6,811
Total		7,583			7,583
Accumulated Depreciation		$ (3,129)			(3,129)
Date of Construction or Acquisition		1995
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 7,583
Deductions during year [Abstract]
Balance at close of year		3,129
Multi-Family Residential [Member] | Rum River - Isanti, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				3,536
Initial Cost to Company [Abstract]
Land					843
Buildings & Improvements					4,823
Costs capitalized subsequent to acquisition					215
Gross amount at which carried at close of period [Abstract]
Land					862
Buildings & Improvements					5,019
Total		5,881			5,881
Accumulated Depreciation		$ (1,020)			(1,020)
Date of Construction or Acquisition		2007
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 5,881
Deductions during year [Abstract]
Balance at close of year		1,020
Multi-Family Residential [Member] | Sherwood - Topeka, KS [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				12,134
Initial Cost to Company [Abstract]
Land					1,142
Buildings & Improvements					14,684
Costs capitalized subsequent to acquisition					3,064
Gross amount at which carried at close of period [Abstract]
Land					1,694
Buildings & Improvements					17,196
Total		18,890			18,890
Accumulated Depreciation		$ (6,619)			(6,619)
Date of Construction or Acquisition		1999
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 18,890
Deductions during year [Abstract]
Balance at close of year		6,619
Multi-Family Residential [Member] | Sierra Vista - Sioux Falls, SD [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				1,390
Initial Cost to Company [Abstract]
Land					241
Buildings & Improvements					2,097
Costs capitalized subsequent to acquisition					435
Gross amount at which carried at close of period [Abstract]
Land					265
Buildings & Improvements					2,508
Total		2,773			2,773
Accumulated Depreciation		$ (273)			(273)
Date of Construction or Acquisition		2011
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 2,773
Deductions during year [Abstract]
Balance at close of year		273
Multi-Family Residential [Member] | Silver Springs - Rapid City, SD [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				2,230
Initial Cost to Company [Abstract]
Land					215
Buildings & Improvements					3,006
Costs capitalized subsequent to acquisition					48
Gross amount at which carried at close of period [Abstract]
Land					215
Buildings & Improvements					3,054
Total		3,269			3,269
Accumulated Depreciation		$ (68)			(68)
Date of Construction or Acquisition		2014
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 3,269
Deductions during year [Abstract]
Balance at close of year		68
Multi-Family Residential [Member] | South Pointe - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				8,613
Initial Cost to Company [Abstract]
Land					550
Buildings & Improvements					9,548
Costs capitalized subsequent to acquisition					2,847
Gross amount at which carried at close of period [Abstract]
Land					1,343
Buildings & Improvements					11,602
Total		12,945			12,945
Accumulated Depreciation		$ (5,494)			(5,494)
Date of Construction or Acquisition		1995
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 12,945
Deductions during year [Abstract]
Balance at close of year		$ 5,494
Multi-Family Residential [Member] | South Pointe - Minot, ND [Member] | Minimum [Member]
Gross amount at which carried at close of period [Abstract]
Life on which depreciation in latest income statement is computed		24 years
Multi-Family Residential [Member] | South Pointe - Minot, ND [Member] | Maximum [Member]
Gross amount at which carried at close of period [Abstract]
Life on which depreciation in latest income statement is computed		40 years
Multi-Family Residential [Member] | Southpoint - Grand Forks, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1],[6]				0
Initial Cost to Company [Abstract]
Land	[6]				576
Buildings & Improvements	[6]				9,893
Costs capitalized subsequent to acquisition	[6]				48
Gross amount at which carried at close of period [Abstract]
Land	[6]				591
Buildings & Improvements	[6]				9,926
Total	[6]	$ 10,517			10,517
Accumulated Depreciation	[6]	$ (414)			(414)
Date of Construction or Acquisition	[6]	2013
Life on which depreciation in latest income statement is computed	[6]	40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year	[6]	$ 10,517
Deductions during year [Abstract]
Balance at close of year	[6]	414
Multi-Family Residential [Member] | Southview - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				1,035
Initial Cost to Company [Abstract]
Land					185
Buildings & Improvements					469
Costs capitalized subsequent to acquisition					410
Gross amount at which carried at close of period [Abstract]
Land					240
Buildings & Improvements					824
Total		1,064			1,064
Accumulated Depreciation		$ (371)			(371)
Date of Construction or Acquisition		1994
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 1,064
Deductions during year [Abstract]
Balance at close of year		371
Multi-Family Residential [Member] | Southwind - Grand Forks, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				5,503
Initial Cost to Company [Abstract]
Land					400
Buildings & Improvements					5,034
Costs capitalized subsequent to acquisition					2,974
Gross amount at which carried at close of period [Abstract]
Land					765
Buildings & Improvements					7,643
Total		8,408			8,408
Accumulated Depreciation		$ (3,486)			(3,486)
Date of Construction or Acquisition		1995
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 8,408
Deductions during year [Abstract]
Balance at close of year		$ 3,486
Multi-Family Residential [Member] | Southwind - Grand Forks, ND [Member] | Minimum [Member]
Gross amount at which carried at close of period [Abstract]
Life on which depreciation in latest income statement is computed		24 years
Multi-Family Residential [Member] | Southwind - Grand Forks, ND [Member] | Maximum [Member]
Gross amount at which carried at close of period [Abstract]
Life on which depreciation in latest income statement is computed		40 years
Multi-Family Residential [Member] | Summit Park - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				963
Initial Cost to Company [Abstract]
Land					161
Buildings & Improvements					1,898
Costs capitalized subsequent to acquisition					1,550
Gross amount at which carried at close of period [Abstract]
Land					560
Buildings & Improvements					3,049
Total		$ 3,609			3,609
Accumulated Depreciation		$ (1,249)			(1,249)
Date of Construction or Acquisition		1997
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 3,609
Deductions during year [Abstract]
Balance at close of year		$ 1,249
Multi-Family Residential [Member] | Summit Park - Minot, ND [Member] | Minimum [Member]
Gross amount at which carried at close of period [Abstract]
Life on which depreciation in latest income statement is computed		24 years
Multi-Family Residential [Member] | Summit Park - Minot, ND [Member] | Maximum [Member]
Gross amount at which carried at close of period [Abstract]
Life on which depreciation in latest income statement is computed		40 years
Multi-Family Residential [Member] | Sunset Trail - Rochester, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				8,009
Initial Cost to Company [Abstract]
Land					336
Buildings & Improvements					12,814
Costs capitalized subsequent to acquisition					2,652
Gross amount at which carried at close of period [Abstract]
Land					581
Buildings & Improvements					15,221
Total		$ 15,802			15,802
Accumulated Depreciation		$ (5,453)			(5,453)
Date of Construction or Acquisition		1999
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 15,802
Deductions during year [Abstract]
Balance at close of year		5,453
Multi-Family Residential [Member] | Temple - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				75
Initial Cost to Company [Abstract]
Land					0
Buildings & Improvements					0
Costs capitalized subsequent to acquisition					231
Gross amount at which carried at close of period [Abstract]
Land					0
Buildings & Improvements					231
Total		231			231
Accumulated Depreciation		$ (57)			(57)
Date of Construction or Acquisition		2006
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 231
Deductions during year [Abstract]
Balance at close of year		57
Multi-Family Residential [Member] | Terrace Heights - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				160
Initial Cost to Company [Abstract]
Land					29
Buildings & Improvements					312
Costs capitalized subsequent to acquisition					142
Gross amount at which carried at close of period [Abstract]
Land					40
Buildings & Improvements					443
Total		483			483
Accumulated Depreciation		$ (172)			(172)
Date of Construction or Acquisition		2006
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 483
Deductions during year [Abstract]
Balance at close of year		172
Multi-Family Residential [Member] | Thomasbrook - Lincoln, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				5,893
Initial Cost to Company [Abstract]
Land					600
Buildings & Improvements					10,306
Costs capitalized subsequent to acquisition					3,336
Gross amount at which carried at close of period [Abstract]
Land					1,403
Buildings & Improvements					12,839
Total		14,242			14,242
Accumulated Depreciation		$ (4,680)			(4,680)
Date of Construction or Acquisition		1999
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 14,242
Deductions during year [Abstract]
Balance at close of year		4,680
Multi-Family Residential [Member] | University Park Place - St. Cloud, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					78
Buildings & Improvements					450
Costs capitalized subsequent to acquisition					115
Gross amount at which carried at close of period [Abstract]
Land					83
Buildings & Improvements					560
Total		643			643
Accumulated Depreciation		$ (118)			(118)
Date of Construction or Acquisition		2007
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 643
Deductions during year [Abstract]
Balance at close of year		118
Multi-Family Residential [Member] | Valley Park - Grand Forks, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				3,822
Initial Cost to Company [Abstract]
Land					294
Buildings & Improvements					4,137
Costs capitalized subsequent to acquisition					3,508
Gross amount at which carried at close of period [Abstract]
Land					1,115
Buildings & Improvements					6,824
Total		7,939			7,939
Accumulated Depreciation		$ (2,599)			(2,599)
Date of Construction or Acquisition		1999
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 7,939
Deductions during year [Abstract]
Balance at close of year		2,599
Multi-Family Residential [Member] | Villa West - Topeka, KS [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				12,106
Initial Cost to Company [Abstract]
Land					1,590
Buildings & Improvements					15,760
Costs capitalized subsequent to acquisition					923
Gross amount at which carried at close of period [Abstract]
Land					1,876
Buildings & Improvements					16,397
Total		18,273			18,273
Accumulated Depreciation		$ (1,331)			(1,331)
Date of Construction or Acquisition		2012
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 18,273
Deductions during year [Abstract]
Balance at close of year		1,331
Multi-Family Residential [Member] | Village Green - Rochester, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				1,047
Initial Cost to Company [Abstract]
Land					234
Buildings & Improvements					2,296
Costs capitalized subsequent to acquisition					962
Gross amount at which carried at close of period [Abstract]
Land					359
Buildings & Improvements					3,133
Total		3,492			3,492
Accumulated Depreciation		$ (935)			(935)
Date of Construction or Acquisition		2003
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 3,492
Deductions during year [Abstract]
Balance at close of year		935
Multi-Family Residential [Member] | West Stonehill - Waite Park, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				8,448
Initial Cost to Company [Abstract]
Land					939
Buildings & Improvements					10,167
Costs capitalized subsequent to acquisition					5,224
Gross amount at which carried at close of period [Abstract]
Land					1,533
Buildings & Improvements					14,797
Total		16,330			16,330
Accumulated Depreciation		$ (6,896)			(6,896)
Date of Construction or Acquisition		1995
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 16,330
Deductions during year [Abstract]
Balance at close of year		6,896
Multi-Family Residential [Member] | Westridge - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				1,604
Initial Cost to Company [Abstract]
Land					68
Buildings & Improvements					1,887
Costs capitalized subsequent to acquisition					263
Gross amount at which carried at close of period [Abstract]
Land					77
Buildings & Improvements					2,141
Total		2,218			2,218
Accumulated Depreciation		$ (377)			(377)
Date of Construction or Acquisition		2008
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 2,218
Deductions during year [Abstract]
Balance at close of year		377
Multi-Family Residential [Member] | Westwood Park - Bismarck, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				1,950
Initial Cost to Company [Abstract]
Land					116
Buildings & Improvements					1,909
Costs capitalized subsequent to acquisition					1,784
Gross amount at which carried at close of period [Abstract]
Land					284
Buildings & Improvements					3,525
Total		3,809			3,809
Accumulated Depreciation		$ (1,425)			(1,425)
Date of Construction or Acquisition		1998
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 3,809
Deductions during year [Abstract]
Balance at close of year		1,425
Multi-Family Residential [Member] | Whispering Ridge - Omaha, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				22,000
Initial Cost to Company [Abstract]
Land					2,139
Buildings & Improvements					25,424
Costs capitalized subsequent to acquisition					732
Gross amount at which carried at close of period [Abstract]
Land					2,276
Buildings & Improvements					26,019
Total		28,295			28,295
Accumulated Depreciation		$ (1,563)			(1,563)
Date of Construction or Acquisition		2012
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 28,295
Deductions during year [Abstract]
Balance at close of year		1,563
Multi-Family Residential [Member] | Williston Garden - Williston, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				10,870
Initial Cost to Company [Abstract]
Land					1,400
Buildings & Improvements					17,696
Costs capitalized subsequent to acquisition					85
Gross amount at which carried at close of period [Abstract]
Land					1,421
Buildings & Improvements					17,760
Total		19,181			19,181
Accumulated Depreciation		$ (2,132)			(2,132)
Date of Construction or Acquisition		2012
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 19,181
Deductions during year [Abstract]
Balance at close of year		2,132
Multi-Family Residential [Member] | Winchester - Rochester, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				2,564
Initial Cost to Company [Abstract]
Land					748
Buildings & Improvements					5,622
Costs capitalized subsequent to acquisition					1,846
Gross amount at which carried at close of period [Abstract]
Land					1,009
Buildings & Improvements					7,207
Total		8,216			8,216
Accumulated Depreciation		$ (2,297)			(2,297)
Date of Construction or Acquisition		2003
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 8,216
Deductions during year [Abstract]
Balance at close of year		2,297
Multi-Family Residential [Member] | Woodridge - Rochester, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				6,257
Initial Cost to Company [Abstract]
Land					370
Buildings & Improvements					6,028
Costs capitalized subsequent to acquisition					2,207
Gross amount at which carried at close of period [Abstract]
Land					642
Buildings & Improvements					7,963
Total		8,605			8,605
Accumulated Depreciation		$ (3,557)			(3,557)
Date of Construction or Acquisition		1997
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 8,605
Deductions during year [Abstract]
Balance at close of year		3,557
Multi-Family Residential [Member] | Renaissance Heights - Williston ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					2,464
Buildings & Improvements					43,488
Costs capitalized subsequent to acquisition					123
Gross amount at which carried at close of period [Abstract]
Land					2,467
Buildings & Improvements					43,608
Total		46,075			46,075
Accumulated Depreciation		$ (848)			(848)
Date of Construction or Acquisition		2013
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 46,075
Deductions during year [Abstract]
Balance at close of year		848
Multi-Family Residential [Member] | Wholly Owned Properties [Member]
Reconciliations of total real estate carrying value [Abstract]
Additions		183,114	84,117	113,859
Office [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				279,307
Initial Cost to Company [Abstract]
Land					62,337
Buildings & Improvements					353,764
Costs capitalized subsequent to acquisition					64,879
Gross amount at which carried at close of period [Abstract]
Land					64,646
Buildings & Improvements					416,334
Total		480,980			480,980
Accumulated Depreciation		(115,710)			(115,710)
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		480,980
Deductions during year [Abstract]
Balance at close of year		115,710
Office [Member] | 1st Avenue Building - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					30
Buildings & Improvements					337
Costs capitalized subsequent to acquisition					0
Gross amount at which carried at close of period [Abstract]
Land					30
Buildings & Improvements					337
Total		367			367
Accumulated Depreciation		$ (41)			(41)
Date of Construction or Acquisition		1981
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 367
Deductions during year [Abstract]
Balance at close of year		$ 41
Office [Member] | 1st Avenue Building - Minot, ND [Member] | Minimum [Member]
Gross amount at which carried at close of period [Abstract]
Life on which depreciation in latest income statement is computed		33 years
Office [Member] | 1st Avenue Building - Minot, ND [Member] | Maximum [Member]
Gross amount at which carried at close of period [Abstract]
Life on which depreciation in latest income statement is computed		40 years
Office [Member] | 610 Business Center IV - Brooklyn Park, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				6,759
Initial Cost to Company [Abstract]
Land					975
Buildings & Improvements					5,542
Costs capitalized subsequent to acquisition					2,886
Gross amount at which carried at close of period [Abstract]
Land					980
Buildings & Improvements					8,423
Total		$ 9,403			9,403
Accumulated Depreciation		$ (2,408)			(2,408)
Date of Construction or Acquisition		2007
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 9,403
Deductions during year [Abstract]
Balance at close of year		2,408
Office [Member] | 7800 West Brown Deer Road - Milwaukee, WI [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				10,320
Initial Cost to Company [Abstract]
Land					1,455
Buildings & Improvements					8,756
Costs capitalized subsequent to acquisition					2,431
Gross amount at which carried at close of period [Abstract]
Land					1,475
Buildings & Improvements					11,167
Total		12,642			12,642
Accumulated Depreciation		$ (4,022)			(4,022)
Date of Construction or Acquisition		2003
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 12,642
Deductions during year [Abstract]
Balance at close of year		4,022
Office [Member] | American Corporate Center - Mendota Heights, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				8,670
Initial Cost to Company [Abstract]
Land					893
Buildings & Improvements					16,768
Costs capitalized subsequent to acquisition					4,067
Gross amount at which carried at close of period [Abstract]
Land					893
Buildings & Improvements					20,835
Total		21,728			21,728
Accumulated Depreciation		$ (8,926)			(8,926)
Date of Construction or Acquisition		2002
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 21,728
Deductions during year [Abstract]
Balance at close of year		8,926
Office [Member] | Ameritrade - Omaha, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				2,020
Initial Cost to Company [Abstract]
Land					327
Buildings & Improvements					7,957
Costs capitalized subsequent to acquisition					65
Gross amount at which carried at close of period [Abstract]
Land					327
Buildings & Improvements					8,022
Total		8,349			8,349
Accumulated Depreciation		$ (3,215)			(3,215)
Date of Construction or Acquisition		1999
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 8,349
Deductions during year [Abstract]
Balance at close of year		3,215
Office [Member] | Benton Business Park - Sauk Rapids, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					188
Buildings & Improvements					1,261
Costs capitalized subsequent to acquisition					87
Gross amount at which carried at close of period [Abstract]
Land					188
Buildings & Improvements					1,348
Total		1,536			1,536
Accumulated Depreciation		$ (429)			(429)
Date of Construction or Acquisition		2003
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 1,536
Deductions during year [Abstract]
Balance at close of year		429
Office [Member] | Bismarck 715 East Broadway - Bismarck, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				2,103
Initial Cost to Company [Abstract]
Land					389
Buildings & Improvements					1,283
Costs capitalized subsequent to acquisition					1,126
Gross amount at which carried at close of period [Abstract]
Land					443
Buildings & Improvements					2,355
Total		2,798			2,798
Accumulated Depreciation		$ (458)			(458)
Date of Construction or Acquisition		2008
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 2,798
Deductions during year [Abstract]
Balance at close of year		458
Office [Member] | Brenwood - Minnetonka, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					1,642
Buildings & Improvements					12,138
Costs capitalized subsequent to acquisition					3,864
Gross amount at which carried at close of period [Abstract]
Land					1,650
Buildings & Improvements					15,994
Total		17,644			17,644
Accumulated Depreciation		$ (5,810)			(5,810)
Date of Construction or Acquisition		2002
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 17,644
Deductions during year [Abstract]
Balance at close of year		5,810
Office [Member] | Brook Valley I - La Vista, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				1,209
Initial Cost to Company [Abstract]
Land					347
Buildings & Improvements					1,671
Costs capitalized subsequent to acquisition					134
Gross amount at which carried at close of period [Abstract]
Land					347
Buildings & Improvements					1,805
Total		2,152			2,152
Accumulated Depreciation		$ (458)			(458)
Date of Construction or Acquisition		2005
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 2,152
Deductions during year [Abstract]
Balance at close of year		458
Office [Member] | Corporate Center West - Omaha, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				17,315
Initial Cost to Company [Abstract]
Land					3,880
Buildings & Improvements					5,253
Costs capitalized subsequent to acquisition					21
Gross amount at which carried at close of period [Abstract]
Land					3,880
Buildings & Improvements					5,274
Total		9,154			9,154
Accumulated Depreciation		$ (126)			(126)
Date of Construction or Acquisition		2006
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 9,154
Deductions during year [Abstract]
Balance at close of year		126
Office [Member] | Crosstown Centre - Eden Prairie, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				9,000
Initial Cost to Company [Abstract]
Land					2,884
Buildings & Improvements					14,569
Costs capitalized subsequent to acquisition					3,183
Gross amount at which carried at close of period [Abstract]
Land					2,980
Buildings & Improvements					17,656
Total		20,636			20,636
Accumulated Depreciation		$ (4,939)			(4,939)
Date of Construction or Acquisition		2004
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 20,636
Deductions during year [Abstract]
Balance at close of year		4,939
Office [Member] | Eden Prairie 6101 Blue Circle Dr - Eden Prairie [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					666
Buildings & Improvements					4,197
Costs capitalized subsequent to acquisition					1
Gross amount at which carried at close of period [Abstract]
Land					666
Buildings & Improvements					4,198
Total		4,864			4,864
Accumulated Depreciation		$ (1,701)			(1,701)
Date of Construction or Acquisition		1999
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 4,864
Deductions during year [Abstract]
Balance at close of year		1,701
Office [Member] | Farnam Executive Center - Omaha, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				12,160
Initial Cost to Company [Abstract]
Land					2,188
Buildings & Improvements					7,912
Costs capitalized subsequent to acquisition					1
Gross amount at which carried at close of period [Abstract]
Land					2,188
Buildings & Improvements					7,913
Total		10,101			10,101
Accumulated Depreciation		$ (190)			(190)
Date of Construction or Acquisition		2006
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 10,101
Deductions during year [Abstract]
Balance at close of year		190
Office [Member] | Flagship - Eden Prairie, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				21,565
Initial Cost to Company [Abstract]
Land					1,899
Buildings & Improvements					15,518
Costs capitalized subsequent to acquisition					31
Gross amount at which carried at close of period [Abstract]
Land					1,913
Buildings & Improvements					15,535
Total		17,448			17,448
Accumulated Depreciation		$ (373)			(373)
Date of Construction or Acquisition		2006
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 17,448
Deductions during year [Abstract]
Balance at close of year		373
Office [Member] | Gateway Corporate Center - Woodbury, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				8,700
Initial Cost to Company [Abstract]
Land					1,637
Buildings & Improvements					6,663
Costs capitalized subsequent to acquisition					0
Gross amount at which carried at close of period [Abstract]
Land					1,637
Buildings & Improvements					6,663
Total		8,300			8,300
Accumulated Depreciation		$ (160)			(160)
Date of Construction or Acquisition		2006
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 8,300
Deductions during year [Abstract]
Balance at close of year		160
Office [Member] | Golden Hills Office Center - Golden Valley, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				17,417
Initial Cost to Company [Abstract]
Land					3,018
Buildings & Improvements					18,544
Costs capitalized subsequent to acquisition					4,313
Gross amount at which carried at close of period [Abstract]
Land					3,018
Buildings & Improvements					22,857
Total		25,875			25,875
Accumulated Depreciation		$ (8,851)			(8,851)
Date of Construction or Acquisition		2003
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 25,875
Deductions during year [Abstract]
Balance at close of year		8,851
Office [Member] | Granite Corporate Center - St. Cloud, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				5,313
Initial Cost to Company [Abstract]
Land					588
Buildings & Improvements					7,808
Costs capitalized subsequent to acquisition					1,521
Gross amount at which carried at close of period [Abstract]
Land					740
Buildings & Improvements					9,177
Total		9,917			9,917
Accumulated Depreciation		$ (3,524)			(3,524)
Date of Construction or Acquisition		2001
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 9,917
Deductions during year [Abstract]
Balance at close of year		3,524
Office [Member] | Great Plains - Fargo, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1],[6]				0
Initial Cost to Company [Abstract]
Land	[6]				126
Buildings & Improvements	[6]				15,240
Costs capitalized subsequent to acquisition	[6]				721
Gross amount at which carried at close of period [Abstract]
Land	[6]				126
Buildings & Improvements	[6]				15,961
Total	[6]	16,087			16,087
Accumulated Depreciation	[6]	$ (6,161)			(6,161)
Date of Construction or Acquisition	[6]	1997
Life on which depreciation in latest income statement is computed	[6]	40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year	[6]	$ 16,087
Deductions during year [Abstract]
Balance at close of year	[6]	6,161
Office [Member] | Highlands Ranch I - Highlands Ranch, CO [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					2,268
Buildings & Improvements					8,362
Costs capitalized subsequent to acquisition					1,117
Gross amount at which carried at close of period [Abstract]
Land					2,268
Buildings & Improvements					9,479
Total		11,747			11,747
Accumulated Depreciation		$ (2,211)			(2,211)
Date of Construction or Acquisition		2006
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 11,747
Deductions during year [Abstract]
Balance at close of year		2,211
Office [Member] | Highlands Ranch II - Highlands Ranch, CO [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					1,437
Buildings & Improvements					9,549
Costs capitalized subsequent to acquisition					1,901
Gross amount at which carried at close of period [Abstract]
Land					1,437
Buildings & Improvements					11,450
Total		12,887			12,887
Accumulated Depreciation		$ (3,391)			(3,391)
Date of Construction or Acquisition		2004
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 12,887
Deductions during year [Abstract]
Balance at close of year		3,391
Office [Member] | Interlachen Corporate Center - Edina, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				8,800
Initial Cost to Company [Abstract]
Land					1,650
Buildings & Improvements					14,983
Costs capitalized subsequent to acquisition					2,530
Gross amount at which carried at close of period [Abstract]
Land					1,693
Buildings & Improvements					17,470
Total		19,163			19,163
Accumulated Depreciation		$ (6,389)			(6,389)
Date of Construction or Acquisition		2001
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 19,163
Deductions during year [Abstract]
Balance at close of year		6,389
Office [Member] | Intertech Building - Fenton, MO [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				4,177
Initial Cost to Company [Abstract]
Land					2,130
Buildings & Improvements					3,968
Costs capitalized subsequent to acquisition					1,721
Gross amount at which carried at close of period [Abstract]
Land					2,191
Buildings & Improvements					5,628
Total		7,819			7,819
Accumulated Depreciation		$ (1,253)			(1,253)
Date of Construction or Acquisition		2007
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 7,819
Deductions during year [Abstract]
Balance at close of year		1,253
Office [Member] | Mendota Office Center I - Mendota Heights, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				3,734
Initial Cost to Company [Abstract]
Land					835
Buildings & Improvements					6,169
Costs capitalized subsequent to acquisition					1,402
Gross amount at which carried at close of period [Abstract]
Land					835
Buildings & Improvements					7,571
Total		8,406			8,406
Accumulated Depreciation		$ (2,683)			(2,683)
Date of Construction or Acquisition		2002
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 8,406
Deductions during year [Abstract]
Balance at close of year		2,683
Office [Member] | Mendota Office Center II - Mendota Heights, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				5,516
Initial Cost to Company [Abstract]
Land					1,121
Buildings & Improvements					10,085
Costs capitalized subsequent to acquisition					2,097
Gross amount at which carried at close of period [Abstract]
Land					1,121
Buildings & Improvements					12,182
Total		13,303			13,303
Accumulated Depreciation		$ (4,882)			(4,882)
Date of Construction or Acquisition		2002
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 13,303
Deductions during year [Abstract]
Balance at close of year		4,882
Office [Member] | Mendota Office Center III - Mendota Heights, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				3,791
Initial Cost to Company [Abstract]
Land					970
Buildings & Improvements					5,734
Costs capitalized subsequent to acquisition					957
Gross amount at which carried at close of period [Abstract]
Land					970
Buildings & Improvements					6,691
Total		7,661			7,661
Accumulated Depreciation		$ (2,419)			(2,419)
Date of Construction or Acquisition		2002
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 7,661
Deductions during year [Abstract]
Balance at close of year		2,419
Office [Member] | Mendota Office Center IV - Mendota Heights, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				4,507
Initial Cost to Company [Abstract]
Land					1,070
Buildings & Improvements					7,635
Costs capitalized subsequent to acquisition					1,510
Gross amount at which carried at close of period [Abstract]
Land					1,070
Buildings & Improvements					9,145
Total		10,215			10,215
Accumulated Depreciation		$ (3,235)			(3,235)
Date of Construction or Acquisition		2002
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 10,215
Deductions during year [Abstract]
Balance at close of year		3,235
Office [Member] | Minnesota National Bank - Duluth, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				628
Initial Cost to Company [Abstract]
Land					287
Buildings & Improvements					1,454
Costs capitalized subsequent to acquisition					224
Gross amount at which carried at close of period [Abstract]
Land					288
Buildings & Improvements					1,677
Total		1,965			1,965
Accumulated Depreciation		$ (475)			(475)
Date of Construction or Acquisition		2004
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 1,965
Deductions during year [Abstract]
Balance at close of year		475
Office [Member] | Minot 1400 31st Ave - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1],[6]				0
Initial Cost to Company [Abstract]
Land	[6]				1,026
Buildings & Improvements	[6]				6,143
Costs capitalized subsequent to acquisition	[6]				4,404
Gross amount at which carried at close of period [Abstract]
Land	[6]				1,038
Buildings & Improvements	[6]				10,535
Total	[6]	11,573			11,573
Accumulated Depreciation	[6]	$ (2,287)			(2,287)
Date of Construction or Acquisition	[6]	2010
Life on which depreciation in latest income statement is computed	[6]	40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year	[6]	$ 11,573
Deductions during year [Abstract]
Balance at close of year	[6]	2,287
Office [Member] | Minot 2505 16th Street SW - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1],[6]				0
Initial Cost to Company [Abstract]
Land	[6]				298
Buildings & Improvements	[6]				1,724
Costs capitalized subsequent to acquisition	[6]				296
Gross amount at which carried at close of period [Abstract]
Land	[6]				298
Buildings & Improvements	[6]				2,020
Total	[6]	2,318			2,318
Accumulated Depreciation	[6]	$ (275)			(275)
Date of Construction or Acquisition	[6]	2009
Life on which depreciation in latest income statement is computed	[6]	40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year	[6]	$ 2,318
Deductions during year [Abstract]
Balance at close of year	[6]	275
Office [Member] | Miracle Hills One - Omaha, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				8,895
Initial Cost to Company [Abstract]
Land					1,974
Buildings & Improvements					5,726
Costs capitalized subsequent to acquisition					6
Gross amount at which carried at close of period [Abstract]
Land					1,974
Buildings & Improvements					5,732
Total		7,706			7,706
Accumulated Depreciation		$ (139)			(139)
Date of Construction or Acquisition		2006
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 7,706
Deductions during year [Abstract]
Balance at close of year		139
Office [Member] | Northpark Corporate Center - Arden Hills, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				11,519
Initial Cost to Company [Abstract]
Land					2,034
Buildings & Improvements					14,584
Costs capitalized subsequent to acquisition					2,497
Gross amount at which carried at close of period [Abstract]
Land					2,037
Buildings & Improvements					17,078
Total		19,115			19,115
Accumulated Depreciation		$ (4,231)			(4,231)
Date of Construction or Acquisition		2006
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 19,115
Deductions during year [Abstract]
Balance at close of year		4,231
Office [Member] | Omaha 10802 Farnam Dr - Omaha, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				5,061
Initial Cost to Company [Abstract]
Land					2,462
Buildings & Improvements					4,374
Costs capitalized subsequent to acquisition					392
Gross amount at which carried at close of period [Abstract]
Land					2,818
Buildings & Improvements					4,410
Total		7,228			7,228
Accumulated Depreciation		$ (525)			(525)
Date of Construction or Acquisition		2010
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 7,228
Deductions during year [Abstract]
Balance at close of year		525
Office [Member] | Pacific Hills - Omaha, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				16,770
Initial Cost to Company [Abstract]
Land					4,220
Buildings & Improvements					6,280
Costs capitalized subsequent to acquisition					243
Gross amount at which carried at close of period [Abstract]
Land					4,220
Buildings & Improvements					6,523
Total		10,743			10,743
Accumulated Depreciation		$ (180)			(180)
Date of Construction or Acquisition		2006
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 10,743
Deductions during year [Abstract]
Balance at close of year		180
Office [Member] | Plaza 16 - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				7,098
Initial Cost to Company [Abstract]
Land					389
Buildings & Improvements					5,444
Costs capitalized subsequent to acquisition					3,860
Gross amount at which carried at close of period [Abstract]
Land					598
Buildings & Improvements					9,095
Total		9,693			9,693
Accumulated Depreciation		$ (2,041)			(2,041)
Date of Construction or Acquisition		2009
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 9,693
Deductions during year [Abstract]
Balance at close of year		2,041
Office [Member] | Plaza VII - Boise, ID [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					300
Buildings & Improvements					913
Costs capitalized subsequent to acquisition					4
Gross amount at which carried at close of period [Abstract]
Land					300
Buildings & Improvements					917
Total		1,217			1,217
Accumulated Depreciation		$ (11)			(11)
Date of Construction or Acquisition		2003
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 1,217
Deductions during year [Abstract]
Balance at close of year		11
Office [Member] | Plymouth 5095 Nathan Lane - Plymouth, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				1,147
Initial Cost to Company [Abstract]
Land					604
Buildings & Improvements					1,253
Costs capitalized subsequent to acquisition					87
Gross amount at which carried at close of period [Abstract]
Land					636
Buildings & Improvements					1,308
Total		1,944			1,944
Accumulated Depreciation		$ (258)			(258)
Date of Construction or Acquisition		2007
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 1,944
Deductions during year [Abstract]
Balance at close of year		258
Office [Member] | Prairie Oak Business Center - Eden Prairie, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				3,120
Initial Cost to Company [Abstract]
Land					531
Buildings & Improvements					4,069
Costs capitalized subsequent to acquisition					2,523
Gross amount at which carried at close of period [Abstract]
Land					1,030
Buildings & Improvements					6,093
Total		7,123			7,123
Accumulated Depreciation		$ (2,365)			(2,365)
Date of Construction or Acquisition		2003
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 7,123
Deductions during year [Abstract]
Balance at close of year		2,365
Office [Member] | Rapid City 900 Concourse Drive - Rapid City, SD [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				181
Initial Cost to Company [Abstract]
Land					285
Buildings & Improvements					6,600
Costs capitalized subsequent to acquisition					1,151
Gross amount at which carried at close of period [Abstract]
Land					514
Buildings & Improvements					7,522
Total		8,036			8,036
Accumulated Depreciation		$ (2,912)			(2,912)
Date of Construction or Acquisition		2000
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 8,036
Deductions during year [Abstract]
Balance at close of year		2,912
Office [Member] | Riverport - Maryland Heights, MO [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				19,690
Initial Cost to Company [Abstract]
Land					1,891
Buildings & Improvements					6,109
Costs capitalized subsequent to acquisition					0
Gross amount at which carried at close of period [Abstract]
Land					1,891
Buildings & Improvements					6,109
Total		8,000			8,000
Accumulated Depreciation		$ (146)			(146)
Date of Construction or Acquisition		2006
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 8,000
Deductions during year [Abstract]
Balance at close of year		146
Office [Member] | Spring Valley IV - Omaha, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				720
Initial Cost to Company [Abstract]
Land					178
Buildings & Improvements					916
Costs capitalized subsequent to acquisition					60
Gross amount at which carried at close of period [Abstract]
Land					186
Buildings & Improvements					968
Total		1,154			1,154
Accumulated Depreciation		$ (259)			(259)
Date of Construction or Acquisition		2005
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 1,154
Deductions during year [Abstract]
Balance at close of year		259
Office [Member] | Spring Valley V - Omaha, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				792
Initial Cost to Company [Abstract]
Land					212
Buildings & Improvements					1,123
Costs capitalized subsequent to acquisition					251
Gross amount at which carried at close of period [Abstract]
Land					240
Buildings & Improvements					1,346
Total		1,586			1,586
Accumulated Depreciation		$ (388)			(388)
Date of Construction or Acquisition		2005
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 1,586
Deductions during year [Abstract]
Balance at close of year		388
Office [Member] | Spring Valley X - Omaha, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				734
Initial Cost to Company [Abstract]
Land					180
Buildings & Improvements					1,024
Costs capitalized subsequent to acquisition					80
Gross amount at which carried at close of period [Abstract]
Land					189
Buildings & Improvements					1,095
Total		1,284			1,284
Accumulated Depreciation		$ (282)			(282)
Date of Construction or Acquisition		2005
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 1,284
Deductions during year [Abstract]
Balance at close of year		282
Office [Member] | Spring Valley XI - Omaha, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				720
Initial Cost to Company [Abstract]
Land					143
Buildings & Improvements					1,094
Costs capitalized subsequent to acquisition					36
Gross amount at which carried at close of period [Abstract]
Land					151
Buildings & Improvements					1,122
Total		1,273			1,273
Accumulated Depreciation		$ (276)			(276)
Date of Construction or Acquisition		2005
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 1,273
Deductions during year [Abstract]
Balance at close of year		276
Office [Member] | Superior Office Building - Duluth, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				944
Initial Cost to Company [Abstract]
Land					336
Buildings & Improvements					2,200
Costs capitalized subsequent to acquisition					143
Gross amount at which carried at close of period [Abstract]
Land					336
Buildings & Improvements					2,343
Total		2,679			2,679
Accumulated Depreciation		$ (688)			(688)
Date of Construction or Acquisition		2004
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 2,679
Deductions during year [Abstract]
Balance at close of year		688
Office [Member] | TCA Building - Eagan, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				7,500
Initial Cost to Company [Abstract]
Land					627
Buildings & Improvements					8,571
Costs capitalized subsequent to acquisition					915
Gross amount at which carried at close of period [Abstract]
Land					684
Buildings & Improvements					9,429
Total		10,113			10,113
Accumulated Depreciation		$ (2,767)			(2,767)
Date of Construction or Acquisition		2003
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 10,113
Deductions during year [Abstract]
Balance at close of year		2,767
Office [Member] | Three Paramount Plaza - Bloomington, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					1,261
Buildings & Improvements					6,149
Costs capitalized subsequent to acquisition					1,961
Gross amount at which carried at close of period [Abstract]
Land					1,482
Buildings & Improvements					7,889
Total		9,371			9,371
Accumulated Depreciation		$ (3,085)			(3,085)
Date of Construction or Acquisition		2002
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 9,371
Deductions during year [Abstract]
Balance at close of year		3,085
Office [Member] | Timberlands - Leawood, KS [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				13,155
Initial Cost to Company [Abstract]
Land					2,375
Buildings & Improvements					9,601
Costs capitalized subsequent to acquisition					189
Gross amount at which carried at close of period [Abstract]
Land					2,375
Buildings & Improvements					9,790
Total		12,165			12,165
Accumulated Depreciation		$ (242)			(242)
Date of Construction or Acquisition		2006
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 12,165
Deductions during year [Abstract]
Balance at close of year		242
Office [Member] | UHC Office - International Falls, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				800
Initial Cost to Company [Abstract]
Land					119
Buildings & Improvements					2,366
Costs capitalized subsequent to acquisition					230
Gross amount at which carried at close of period [Abstract]
Land					119
Buildings & Improvements					2,596
Total		2,715			2,715
Accumulated Depreciation		$ (734)			(734)
Date of Construction or Acquisition		2004
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 2,715
Deductions during year [Abstract]
Balance at close of year		734
Office [Member] | US Bank Financial Center - Bloomington, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				12,766
Initial Cost to Company [Abstract]
Land					3,117
Buildings & Improvements					13,350
Costs capitalized subsequent to acquisition					2,023
Gross amount at which carried at close of period [Abstract]
Land					3,195
Buildings & Improvements					15,295
Total		18,490			18,490
Accumulated Depreciation		$ (3,805)			(3,805)
Date of Construction or Acquisition		2005
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 18,490
Deductions during year [Abstract]
Balance at close of year		3,805
Office [Member] | Wells Fargo Center - St Cloud, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				5,787
Initial Cost to Company [Abstract]
Land					869
Buildings & Improvements					8,373
Costs capitalized subsequent to acquisition					1,956
Gross amount at which carried at close of period [Abstract]
Land					884
Buildings & Improvements					10,314
Total		11,198			11,198
Accumulated Depreciation		$ (2,641)			(2,641)
Date of Construction or Acquisition		2005
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 11,198
Deductions during year [Abstract]
Balance at close of year		2,641
Office [Member] | West River Business Park - Waite Park, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					235
Buildings & Improvements					1,195
Costs capitalized subsequent to acquisition					267
Gross amount at which carried at close of period [Abstract]
Land					235
Buildings & Improvements					1,462
Total		1,697			1,697
Accumulated Depreciation		$ (430)			(430)
Date of Construction or Acquisition		2003
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 1,697
Deductions during year [Abstract]
Balance at close of year		430
Office [Member] | Westgate - Boise, ID [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				3,844
Initial Cost to Company [Abstract]
Land					1,000
Buildings & Improvements					10,618
Costs capitalized subsequent to acquisition					1,933
Gross amount at which carried at close of period [Abstract]
Land					1,000
Buildings & Improvements					12,551
Total		13,551			13,551
Accumulated Depreciation		$ (4,512)			(4,512)
Date of Construction or Acquisition		2003
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 13,551
Deductions during year [Abstract]
Balance at close of year		4,512
Office [Member] | Woodlands Plaza IV - Maryland Heights, MO [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				4,360
Initial Cost to Company [Abstract]
Land					771
Buildings & Improvements					4,609
Costs capitalized subsequent to acquisition					1,461
Gross amount at which carried at close of period [Abstract]
Land					862
Buildings & Improvements					5,979
Total		6,841			6,841
Accumulated Depreciation		$ (1,501)			(1,501)
Date of Construction or Acquisition		2006
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 6,841
Deductions during year [Abstract]
Balance at close of year		1,501
Office [Member] | Wholly Owned Properties [Member]
Reconciliations of total real estate carrying value [Abstract]
Additions		0	0	0
Commercial Healthcare [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				221,439
Initial Cost to Company [Abstract]
Land					33,906
Buildings & Improvements					411,712
Costs capitalized subsequent to acquisition					52,379
Gross amount at which carried at close of period [Abstract]
Land					34,593
Buildings & Improvements					463,404
Total		497,997			497,997
Accumulated Depreciation		(113,062)			(113,062)
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		497,997
Deductions during year [Abstract]
Balance at close of year		113,062
Commercial Healthcare [Member] | 2800 Medical Building - Minneapolis, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				7,740
Initial Cost to Company [Abstract]
Land					204
Buildings & Improvements					7,135
Costs capitalized subsequent to acquisition					2,492
Gross amount at which carried at close of period [Abstract]
Land					229
Buildings & Improvements					9,602
Total		9,831			9,831
Accumulated Depreciation		$ (3,037)			(3,037)
Date of Construction or Acquisition		2005
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 9,831
Deductions during year [Abstract]
Balance at close of year		3,037
Commercial Healthcare [Member] | 2828 Chicago Avenue - Minneapolis, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				12,105
Initial Cost to Company [Abstract]
Land					726
Buildings & Improvements					11,319
Costs capitalized subsequent to acquisition					5,627
Gross amount at which carried at close of period [Abstract]
Land					729
Buildings & Improvements					16,943
Total		17,672			17,672
Accumulated Depreciation		$ (4,011)			(4,011)
Date of Construction or Acquisition		2007
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 17,672
Deductions during year [Abstract]
Balance at close of year		4,011
Commercial Healthcare [Member] | Airport Medical - Bloomington, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				431
Initial Cost to Company [Abstract]
Land					0
Buildings & Improvements					4,678
Costs capitalized subsequent to acquisition					0
Gross amount at which carried at close of period [Abstract]
Land					0
Buildings & Improvements					4,678
Total		4,678			4,678
Accumulated Depreciation		$ (1,730)			(1,730)
Date of Construction or Acquisition		2002
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 4,678
Deductions during year [Abstract]
Balance at close of year		1,730
Commercial Healthcare [Member] | Barry Pointe Office Park - Kansas City, MO [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				1,369
Initial Cost to Company [Abstract]
Land					384
Buildings & Improvements					2,366
Costs capitalized subsequent to acquisition					226
Gross amount at which carried at close of period [Abstract]
Land					392
Buildings & Improvements					2,584
Total		2,976			2,976
Accumulated Depreciation		$ (547)			(547)
Date of Construction or Acquisition		2007
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 2,976
Deductions during year [Abstract]
Balance at close of year		547
Commercial Healthcare [Member] | Billings 2300 Grant Road - Billings, MT [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				1,226
Initial Cost to Company [Abstract]
Land					649
Buildings & Improvements					1,216
Costs capitalized subsequent to acquisition					0
Gross amount at which carried at close of period [Abstract]
Land					649
Buildings & Improvements					1,216
Total		1,865			1,865
Accumulated Depreciation		$ (146)			(146)
Date of Construction or Acquisition		2010
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 1,865
Deductions during year [Abstract]
Balance at close of year		146
Commercial Healthcare [Member] | Burnsville 303 Nicollet Medical (Ridgeview) - Burnsville, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				8,092
Initial Cost to Company [Abstract]
Land					1,071
Buildings & Improvements					6,842
Costs capitalized subsequent to acquisition					1,968
Gross amount at which carried at close of period [Abstract]
Land					1,092
Buildings & Improvements					8,789
Total		9,881			9,881
Accumulated Depreciation		$ (1,612)			(1,612)
Date of Construction or Acquisition		2008
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 9,881
Deductions during year [Abstract]
Balance at close of year		1,612
Commercial Healthcare [Member] | Burnsville 305 Nicollet Medical (Ridgeview South) - Burnsville, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				5,066
Initial Cost to Company [Abstract]
Land					189
Buildings & Improvements					5,127
Costs capitalized subsequent to acquisition					971
Gross amount at which carried at close of period [Abstract]
Land					203
Buildings & Improvements					6,084
Total		6,287			6,287
Accumulated Depreciation		$ (1,078)			(1,078)
Date of Construction or Acquisition		2008
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 6,287
Deductions during year [Abstract]
Balance at close of year		1,078
Commercial Healthcare [Member] | Casper 1930 E 12th Street (Park Place) - Casper, WY [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1],[6]				0
Initial Cost to Company [Abstract]
Land	[6]				439
Buildings & Improvements	[6]				5,780
Costs capitalized subsequent to acquisition	[6]				172
Gross amount at which carried at close of period [Abstract]
Land	[6]				439
Buildings & Improvements	[6]				5,952
Total	[6]	6,391			6,391
Accumulated Depreciation	[6]	$ (855)			(855)
Date of Construction or Acquisition	[6]	2009
Life on which depreciation in latest income statement is computed	[6]	40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year	[6]	$ 6,391
Deductions during year [Abstract]
Balance at close of year	[6]	855
Commercial Healthcare [Member] | Casper 3955 E 12th Street (Meadow Wind) - Casper, WY [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1],[6]				0
Initial Cost to Company [Abstract]
Land	[6]				388
Buildings & Improvements	[6]				10,494
Costs capitalized subsequent to acquisition	[6]				576
Gross amount at which carried at close of period [Abstract]
Land	[6]				459
Buildings & Improvements	[6]				10,999
Total	[6]	11,458			11,458
Accumulated Depreciation	[6]	$ (1,510)			(1,510)
Date of Construction or Acquisition	[6]	2009
Life on which depreciation in latest income statement is computed	[6]	40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year	[6]	$ 11,458
Deductions during year [Abstract]
Balance at close of year	[6]	1,510
Commercial Healthcare [Member] | Cheyenne 4010 N College Drive (Aspen Wind) - Cheyenne, WY [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1],[6]				0
Initial Cost to Company [Abstract]
Land	[6]				628
Buildings & Improvements	[6]				10,272
Costs capitalized subsequent to acquisition	[6]				270
Gross amount at which carried at close of period [Abstract]
Land	[6]				629
Buildings & Improvements	[6]				10,541
Total	[6]	11,170			11,170
Accumulated Depreciation	[6]	$ (1,457)			(1,457)
Date of Construction or Acquisition	[6]	2009
Life on which depreciation in latest income statement is computed	[6]	40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year	[6]	$ 11,170
Deductions during year [Abstract]
Balance at close of year	[6]	1,457
Commercial Healthcare [Member] | Cheyenne 4606 N College Drive (Sierra Hills) - Cheyenne, WY [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1],[6]				0
Initial Cost to Company [Abstract]
Land	[6]				695
Buildings & Improvements	[6]				7,455
Costs capitalized subsequent to acquisition	[6]				50
Gross amount at which carried at close of period [Abstract]
Land	[6]				695
Buildings & Improvements	[6]				7,505
Total	[6]	8,200			8,200
Accumulated Depreciation	[6]	$ (1,020)			(1,020)
Date of Construction or Acquisition	[6]	2009
Life on which depreciation in latest income statement is computed	[6]	40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year	[6]	$ 8,200
Deductions during year [Abstract]
Balance at close of year	[6]	1,020
Commercial Healthcare [Member] | Denfeld Clinic - Duluth, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				1,430
Initial Cost to Company [Abstract]
Land					501
Buildings & Improvements					2,597
Costs capitalized subsequent to acquisition					1
Gross amount at which carried at close of period [Abstract]
Land					501
Buildings & Improvements					2,598
Total		3,099			3,099
Accumulated Depreciation		$ (718)			(718)
Date of Construction or Acquisition		2004
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 3,099
Deductions during year [Abstract]
Balance at close of year		718
Commercial Healthcare [Member] | Eagan 1440 Duckwood Medical - Eagan, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					521
Buildings & Improvements					1,547
Costs capitalized subsequent to acquisition					556
Gross amount at which carried at close of period [Abstract]
Land					521
Buildings & Improvements					2,103
Total		2,624			2,624
Accumulated Depreciation		$ (635)			(635)
Date of Construction or Acquisition		2008
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 2,624
Deductions during year [Abstract]
Balance at close of year		635
Commercial Healthcare [Member] | Edgewood Vista - Belgrade, MT [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					35
Buildings & Improvements					779
Costs capitalized subsequent to acquisition					21
Gross amount at which carried at close of period [Abstract]
Land					35
Buildings & Improvements					800
Total		835			835
Accumulated Depreciation		$ (140)			(140)
Date of Construction or Acquisition		2008
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 835
Deductions during year [Abstract]
Balance at close of year		140
Commercial Healthcare [Member] | Edgewood Vista - Billings, MT [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				1,785
Initial Cost to Company [Abstract]
Land					115
Buildings & Improvements					1,767
Costs capitalized subsequent to acquisition					66
Gross amount at which carried at close of period [Abstract]
Land					115
Buildings & Improvements					1,833
Total		1,948			1,948
Accumulated Depreciation		$ (323)			(323)
Date of Construction or Acquisition		2008
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 1,948
Deductions during year [Abstract]
Balance at close of year		323
Commercial Healthcare [Member] | Edgewood Vista - Bismarck, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					511
Buildings & Improvements					9,193
Costs capitalized subsequent to acquisition					177
Gross amount at which carried at close of period [Abstract]
Land					511
Buildings & Improvements					9,370
Total		9,881			9,881
Accumulated Depreciation		$ (2,231)			(2,231)
Date of Construction or Acquisition		2005
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 9,881
Deductions during year [Abstract]
Balance at close of year		2,231
Commercial Healthcare [Member] | Edgewood Vista - Brainerd, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					587
Buildings & Improvements					8,999
Costs capitalized subsequent to acquisition					134
Gross amount at which carried at close of period [Abstract]
Land					587
Buildings & Improvements					9,133
Total		9,720			9,720
Accumulated Depreciation		$ (2,184)			(2,184)
Date of Construction or Acquisition		2005
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 9,720
Deductions during year [Abstract]
Balance at close of year		2,184
Commercial Healthcare [Member] | Edgewood Vista - Columbus, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					43
Buildings & Improvements					824
Costs capitalized subsequent to acquisition					24
Gross amount at which carried at close of period [Abstract]
Land					44
Buildings & Improvements					847
Total		891			891
Accumulated Depreciation		$ (148)			(148)
Date of Construction or Acquisition		2008
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 891
Deductions during year [Abstract]
Balance at close of year		148
Commercial Healthcare [Member] | Edgewood Vista - East Grand Forks, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				2,718
Initial Cost to Company [Abstract]
Land					290
Buildings & Improvements					1,352
Costs capitalized subsequent to acquisition					59
Gross amount at which carried at close of period [Abstract]
Land					290
Buildings & Improvements					1,411
Total		1,701			1,701
Accumulated Depreciation		$ (251)			(251)
Date of Construction or Acquisition		2000
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 1,701
Deductions during year [Abstract]
Balance at close of year		251
Commercial Healthcare [Member] | Edgewood Vista - Fargo, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				11,846
Initial Cost to Company [Abstract]
Land					775
Buildings & Improvements					20,870
Costs capitalized subsequent to acquisition					199
Gross amount at which carried at close of period [Abstract]
Land					775
Buildings & Improvements					21,069
Total		21,844			21,844
Accumulated Depreciation		$ (3,730)			(3,730)
Date of Construction or Acquisition		2008
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 21,844
Deductions during year [Abstract]
Balance at close of year		3,730
Commercial Healthcare [Member] | Edgewood Vista - Fremont, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				550
Initial Cost to Company [Abstract]
Land					56
Buildings & Improvements					490
Costs capitalized subsequent to acquisition					54
Gross amount at which carried at close of period [Abstract]
Land					56
Buildings & Improvements					544
Total		600			600
Accumulated Depreciation		$ (179)			(179)
Date of Construction or Acquisition		2008
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 600
Deductions during year [Abstract]
Balance at close of year		179
Commercial Healthcare [Member] | Edgewood Vista - Grand Island, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					33
Buildings & Improvements					773
Costs capitalized subsequent to acquisition					51
Gross amount at which carried at close of period [Abstract]
Land					39
Buildings & Improvements					818
Total		857			857
Accumulated Depreciation		$ (142)			(142)
Date of Construction or Acquisition		2008
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 857
Deductions during year [Abstract]
Balance at close of year		142
Commercial Healthcare [Member] | Edgewood Vista - Hastings, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				567
Initial Cost to Company [Abstract]
Land					49
Buildings & Improvements					517
Costs capitalized subsequent to acquisition					63
Gross amount at which carried at close of period [Abstract]
Land					50
Buildings & Improvements					579
Total		629			629
Accumulated Depreciation		$ (197)			(197)
Date of Construction or Acquisition		2008
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 629
Deductions during year [Abstract]
Balance at close of year		197
Commercial Healthcare [Member] | Edgewood Vista - Hermantown I, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				15,197
Initial Cost to Company [Abstract]
Land					288
Buildings & Improvements					9,871
Costs capitalized subsequent to acquisition					1,761
Gross amount at which carried at close of period [Abstract]
Land					288
Buildings & Improvements					11,632
Total		11,920			11,920
Accumulated Depreciation		$ (3,888)			(3,888)
Date of Construction or Acquisition		2000
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 11,920
Deductions during year [Abstract]
Balance at close of year		3,888
Commercial Healthcare [Member] | Edgewood Vista - Hermantown II, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					719
Buildings & Improvements					10,517
Costs capitalized subsequent to acquisition					121
Gross amount at which carried at close of period [Abstract]
Land					719
Buildings & Improvements					10,638
Total		11,357			11,357
Accumulated Depreciation		$ (2,542)			(2,542)
Date of Construction or Acquisition		2005
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 11,357
Deductions during year [Abstract]
Balance at close of year		2,542
Commercial Healthcare [Member] | Edgewood Vista - Kalispell, MT [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				568
Initial Cost to Company [Abstract]
Land					70
Buildings & Improvements					502
Costs capitalized subsequent to acquisition					633
Gross amount at which carried at close of period [Abstract]
Land					70
Buildings & Improvements					1,135
Total		1,205			1,205
Accumulated Depreciation		$ (364)			(364)
Date of Construction or Acquisition		2001
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 1,205
Deductions during year [Abstract]
Balance at close of year		364
Commercial Healthcare [Member] | Edgewood Vista - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				9,017
Initial Cost to Company [Abstract]
Land					1,045
Buildings & Improvements					11,590
Costs capitalized subsequent to acquisition					210
Gross amount at which carried at close of period [Abstract]
Land					1,047
Buildings & Improvements					11,798
Total		12,845			12,845
Accumulated Depreciation		$ (1,307)			(1,307)
Date of Construction or Acquisition		2010
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 12,845
Deductions during year [Abstract]
Balance at close of year		1,307
Commercial Healthcare [Member] | Edgewood Vista - Missoula, MT [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				807
Initial Cost to Company [Abstract]
Land					109
Buildings & Improvements					854
Costs capitalized subsequent to acquisition					94
Gross amount at which carried at close of period [Abstract]
Land					116
Buildings & Improvements					941
Total		1,057			1,057
Accumulated Depreciation		$ (412)			(412)
Date of Construction or Acquisition		1996
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 1,057
Deductions during year [Abstract]
Balance at close of year		412
Commercial Healthcare [Member] | Edgewood Vista - Norfolk, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					42
Buildings & Improvements					722
Costs capitalized subsequent to acquisition					22
Gross amount at which carried at close of period [Abstract]
Land					42
Buildings & Improvements					744
Total		786			786
Accumulated Depreciation		$ (131)			(131)
Date of Construction or Acquisition		2008
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 786
Deductions during year [Abstract]
Balance at close of year		131
Commercial Healthcare [Member] | Edgewood Vista - Omaha, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				359
Initial Cost to Company [Abstract]
Land					89
Buildings & Improvements					547
Costs capitalized subsequent to acquisition					53
Gross amount at which carried at close of period [Abstract]
Land					89
Buildings & Improvements					600
Total		689			689
Accumulated Depreciation		$ (201)			(201)
Date of Construction or Acquisition		2001
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 689
Deductions during year [Abstract]
Balance at close of year		201
Commercial Healthcare [Member] | Edgewood Vista - Sioux Falls, SD [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				1,022
Initial Cost to Company [Abstract]
Land					314
Buildings & Improvements					974
Costs capitalized subsequent to acquisition					58
Gross amount at which carried at close of period [Abstract]
Land					314
Buildings & Improvements					1,032
Total		1,346			1,346
Accumulated Depreciation		$ (185)			(185)
Date of Construction or Acquisition		2008
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 1,346
Deductions during year [Abstract]
Balance at close of year		185
Commercial Healthcare [Member] | Edgewood Vista - Spearfish, SD [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					315
Buildings & Improvements					8,584
Costs capitalized subsequent to acquisition					124
Gross amount at which carried at close of period [Abstract]
Land					330
Buildings & Improvements					8,693
Total		9,023			9,023
Accumulated Depreciation		$ (1,710)			(1,710)
Date of Construction or Acquisition		2005
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 9,023
Deductions during year [Abstract]
Balance at close of year		1,710
Commercial Healthcare [Member] | Edgewood Vista - Virginia, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				12,927
Initial Cost to Company [Abstract]
Land					246
Buildings & Improvements					11,823
Costs capitalized subsequent to acquisition					313
Gross amount at which carried at close of period [Abstract]
Land					246
Buildings & Improvements					12,136
Total		12,382			12,382
Accumulated Depreciation		$ (3,669)			(3,669)
Date of Construction or Acquisition		2002
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 12,382
Deductions during year [Abstract]
Balance at close of year		3,669
Commercial Healthcare [Member] | Edina 6363 France Medical - Edina, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				9,567
Initial Cost to Company [Abstract]
Land					0
Buildings & Improvements					12,675
Costs capitalized subsequent to acquisition					2,906
Gross amount at which carried at close of period [Abstract]
Land					0
Buildings & Improvements					15,581
Total		15,581			15,581
Accumulated Depreciation		$ (3,781)			(3,781)
Date of Construction or Acquisition		2008
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 15,581
Deductions during year [Abstract]
Balance at close of year		3,781
Commercial Healthcare [Member] | Edina 6405 France Medical - Edina, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				8,145
Initial Cost to Company [Abstract]
Land					0
Buildings & Improvements					12,201
Costs capitalized subsequent to acquisition					41
Gross amount at which carried at close of period [Abstract]
Land					0
Buildings & Improvements					12,242
Total		12,242			12,242
Accumulated Depreciation		$ (2,969)			(2,969)
Date of Construction or Acquisition		2008
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 12,242
Deductions during year [Abstract]
Balance at close of year		2,969
Commercial Healthcare [Member] | Edina 6517 Drew Avenue - Edina, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					353
Buildings & Improvements					660
Costs capitalized subsequent to acquisition					529
Gross amount at which carried at close of period [Abstract]
Land					372
Buildings & Improvements					1,170
Total		1,542			1,542
Accumulated Depreciation		$ (579)			(579)
Date of Construction or Acquisition		2002
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 1,542
Deductions during year [Abstract]
Balance at close of year		579
Commercial Healthcare [Member] | Edina 6525 Drew Avenue - Edina, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					388
Buildings & Improvements					117
Costs capitalized subsequent to acquisition					0
Gross amount at which carried at close of period [Abstract]
Land					388
Buildings & Improvements					117
Total		505			505
Accumulated Depreciation		$ (10)			(10)
Date of Construction or Acquisition		2011
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 505
Deductions during year [Abstract]
Balance at close of year		10
Commercial Healthcare [Member] | Edina 6525 France SMC II - Edina, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				9,803
Initial Cost to Company [Abstract]
Land					755
Buildings & Improvements					8,054
Costs capitalized subsequent to acquisition					5,723
Gross amount at which carried at close of period [Abstract]
Land					1,040
Buildings & Improvements					13,492
Total		14,532			14,532
Accumulated Depreciation		$ (5,874)			(5,874)
Date of Construction or Acquisition		2003
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 14,532
Deductions during year [Abstract]
Balance at close of year		5,874
Commercial Healthcare [Member] | Edina 6545 France SMC I - Edina MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				29,622
Initial Cost to Company [Abstract]
Land					3,480
Buildings & Improvements					30,192
Costs capitalized subsequent to acquisition					14,423
Gross amount at which carried at close of period [Abstract]
Land					3,480
Buildings & Improvements					44,615
Total		48,095			48,095
Accumulated Depreciation		$ (17,035)			(17,035)
Date of Construction or Acquisition		2001
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 48,095
Deductions during year [Abstract]
Balance at close of year		17,035
Commercial Healthcare [Member] | Fresenius - Duluth, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				576
Initial Cost to Company [Abstract]
Land					50
Buildings & Improvements					1,520
Costs capitalized subsequent to acquisition					2
Gross amount at which carried at close of period [Abstract]
Land					50
Buildings & Improvements					1,522
Total		1,572			1,572
Accumulated Depreciation		$ (420)			(420)
Date of Construction or Acquisition		2004
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 1,572
Deductions during year [Abstract]
Balance at close of year		420
Commercial Healthcare [Member] | Garden View - St. Paul, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					0
Buildings & Improvements					7,408
Costs capitalized subsequent to acquisition					898
Gross amount at which carried at close of period [Abstract]
Land					26
Buildings & Improvements					8,280
Total		8,306			8,306
Accumulated Depreciation		$ (2,723)			(2,723)
Date of Construction or Acquisition		2002
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 8,306
Deductions during year [Abstract]
Balance at close of year		2,723
Commercial Healthcare [Member] | Gateway Clinic - Sandstone, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				828
Initial Cost to Company [Abstract]
Land					66
Buildings & Improvements					1,699
Costs capitalized subsequent to acquisition					0
Gross amount at which carried at close of period [Abstract]
Land					66
Buildings & Improvements					1,699
Total		1,765			1,765
Accumulated Depreciation		$ (469)			(469)
Date of Construction or Acquisition		2004
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 1,765
Deductions during year [Abstract]
Balance at close of year		469
Commercial Healthcare [Member] | Healtheast St John & Woodwinds - Maplewood & Woodbury, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				7,366
Initial Cost to Company [Abstract]
Land					3,239
Buildings & Improvements					18,362
Costs capitalized subsequent to acquisition					0
Gross amount at which carried at close of period [Abstract]
Land					3,239
Buildings & Improvements					18,362
Total		21,601			21,601
Accumulated Depreciation		$ (6,867)			(6,867)
Date of Construction or Acquisition		2000
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 21,601
Deductions during year [Abstract]
Balance at close of year		6,867
Commercial Healthcare [Member] | High Pointe Health Campus - Lake Elmo, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				7,500
Initial Cost to Company [Abstract]
Land					1,305
Buildings & Improvements					10,528
Costs capitalized subsequent to acquisition					2,091
Gross amount at which carried at close of period [Abstract]
Land					1,329
Buildings & Improvements					12,595
Total		13,924			13,924
Accumulated Depreciation		$ (3,750)			(3,750)
Date of Construction or Acquisition		2004
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 13,924
Deductions during year [Abstract]
Balance at close of year		3,750
Commercial Healthcare [Member] | Laramie 1072 N 22nd Street (Spring Wind) - Laramie, WY [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1],[6]				0
Initial Cost to Company [Abstract]
Land	[6]				406
Buildings & Improvements	[6]				10,151
Costs capitalized subsequent to acquisition	[6]				27
Gross amount at which carried at close of period [Abstract]
Land	[6]				406
Buildings & Improvements	[6]				10,178
Total	[6]	10,584			10,584
Accumulated Depreciation	[6]	$ (1,251)			(1,251)
Date of Construction or Acquisition	[6]	2009
Life on which depreciation in latest income statement is computed	[6]	40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year	[6]	$ 10,584
Deductions during year [Abstract]
Balance at close of year	[6]	1,251
Commercial Healthcare [Member] | Legends at Heritage Place - Sartell, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					970
Buildings & Improvements					9,920
Costs capitalized subsequent to acquisition					0
Gross amount at which carried at close of period [Abstract]
Land					970
Buildings & Improvements					9,920
Total		10,890			10,890
Accumulated Depreciation		$ (382)			(382)
Date of Construction or Acquisition		2013
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 10,890
Deductions during year [Abstract]
Balance at close of year		382
Commercial Healthcare [Member] | Mariner Clinic - Superior, WI [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				1,811
Initial Cost to Company [Abstract]
Land					0
Buildings & Improvements					3,781
Costs capitalized subsequent to acquisition					90
Gross amount at which carried at close of period [Abstract]
Land					20
Buildings & Improvements					3,851
Total		3,871			3,871
Accumulated Depreciation		$ (1,077)			(1,077)
Date of Construction or Acquisition		2004
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 3,871
Deductions during year [Abstract]
Balance at close of year		1,077
Commercial Healthcare [Member] | Minneapolis 701 25th Avenue Medical - Minneapolis, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				7,196
Initial Cost to Company [Abstract]
Land					0
Buildings & Improvements					7,873
Costs capitalized subsequent to acquisition					1,566
Gross amount at which carried at close of period [Abstract]
Land					0
Buildings & Improvements					9,439
Total		9,439			9,439
Accumulated Depreciation		$ (1,837)			(1,837)
Date of Construction or Acquisition		2008
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 9,439
Deductions during year [Abstract]
Balance at close of year		1,837
Commercial Healthcare [Member] | Missoula 3050 Great Northern - Missoula, MT [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				1,267
Initial Cost to Company [Abstract]
Land					640
Buildings & Improvements					1,331
Costs capitalized subsequent to acquisition					0
Gross amount at which carried at close of period [Abstract]
Land					640
Buildings & Improvements					1,331
Total		1,971			1,971
Accumulated Depreciation		$ (159)			(159)
Date of Construction or Acquisition		2010
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 1,971
Deductions during year [Abstract]
Balance at close of year		159
Commercial Healthcare [Member] | Park Dental - Brooklyn Center, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				247
Initial Cost to Company [Abstract]
Land					185
Buildings & Improvements					2,767
Costs capitalized subsequent to acquisition					0
Gross amount at which carried at close of period [Abstract]
Land					185
Buildings & Improvements					2,767
Total		2,952			2,952
Accumulated Depreciation		$ (873)			(873)
Date of Construction or Acquisition		2002
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 2,952
Deductions during year [Abstract]
Balance at close of year		873
Commercial Healthcare [Member] | Pavilion I - Duluth, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				4,773
Initial Cost to Company [Abstract]
Land					1,245
Buildings & Improvements					8,898
Costs capitalized subsequent to acquisition					31
Gross amount at which carried at close of period [Abstract]
Land					1,245
Buildings & Improvements					8,929
Total		10,174			10,174
Accumulated Depreciation		$ (2,445)			(2,445)
Date of Construction or Acquisition		2004
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 10,174
Deductions during year [Abstract]
Balance at close of year		2,445
Commercial Healthcare [Member] | Pavilion II - Duluth, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				8,783
Initial Cost to Company [Abstract]
Land					2,715
Buildings & Improvements					14,673
Costs capitalized subsequent to acquisition					1,937
Gross amount at which carried at close of period [Abstract]
Land					2,715
Buildings & Improvements					16,610
Total		19,325			19,325
Accumulated Depreciation		$ (5,788)			(5,788)
Date of Construction or Acquisition		2004
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 19,325
Deductions during year [Abstract]
Balance at close of year		5,788
Commercial Healthcare [Member] | Ritchie Medical Plaza - St Paul, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				5,980
Initial Cost to Company [Abstract]
Land					1,615
Buildings & Improvements					7,851
Costs capitalized subsequent to acquisition					3,611
Gross amount at which carried at close of period [Abstract]
Land					1,647
Buildings & Improvements					11,430
Total		13,077			13,077
Accumulated Depreciation		$ (2,880)			(2,880)
Date of Construction or Acquisition		2005
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 13,077
Deductions during year [Abstract]
Balance at close of year		2,880
Commercial Healthcare [Member] | Sartell 2000 23rd Street South - Sartell, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				1,593
Initial Cost to Company [Abstract]
Land					0
Buildings & Improvements					11,781
Costs capitalized subsequent to acquisition					934
Gross amount at which carried at close of period [Abstract]
Land					0
Buildings & Improvements					12,715
Total		12,715			12,715
Accumulated Depreciation		$ (4,101)			(4,101)
Date of Construction or Acquisition		2002
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 12,715
Deductions during year [Abstract]
Balance at close of year		4,101
Commercial Healthcare [Member] | Spring Creek American Falls- American Falls, ID [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				2,086
Initial Cost to Company [Abstract]
Land					145
Buildings & Improvements					3,870
Costs capitalized subsequent to acquisition					0
Gross amount at which carried at close of period [Abstract]
Land					145
Buildings & Improvements					3,870
Total		4,015			4,015
Accumulated Depreciation		$ (404)			(404)
Date of Construction or Acquisition		2011
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 4,015
Deductions during year [Abstract]
Balance at close of year		404
Commercial Healthcare [Member] | Spring Creek-Boise - Boise, ID [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				2,751
Initial Cost to Company [Abstract]
Land					708
Buildings & Improvements					4,296
Costs capitalized subsequent to acquisition					0
Gross amount at which carried at close of period [Abstract]
Land					708
Buildings & Improvements					4,296
Total		5,004			5,004
Accumulated Depreciation		$ (482)			(482)
Date of Construction or Acquisition		2011
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 5,004
Deductions during year [Abstract]
Balance at close of year		482
Commercial Healthcare [Member] | Spring Creek-Eagle - Eagle, ID [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				1,919
Initial Cost to Company [Abstract]
Land					263
Buildings & Improvements					3,775
Costs capitalized subsequent to acquisition					0
Gross amount at which carried at close of period [Abstract]
Land					263
Buildings & Improvements					3,775
Total		4,038			4,038
Accumulated Depreciation		$ (396)			(396)
Date of Construction or Acquisition		2011
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 4,038
Deductions during year [Abstract]
Balance at close of year		396
Commercial Healthcare [Member] | Spring Creek Fruitland - Fruitland, ID [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					550
Buildings & Improvements					6,565
Costs capitalized subsequent to acquisition					0
Gross amount at which carried at close of period [Abstract]
Land					550
Buildings & Improvements					6,565
Total		7,115			7,115
Accumulated Depreciation		$ (260)			(260)
Date of Construction or Acquisition		2014
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 7,115
Deductions during year [Abstract]
Balance at close of year		260
Commercial Healthcare [Member] | Spring Creek-Meridian - Meridian, ID [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				3,171
Initial Cost to Company [Abstract]
Land					424
Buildings & Improvements					6,724
Costs capitalized subsequent to acquisition					0
Gross amount at which carried at close of period [Abstract]
Land					424
Buildings & Improvements					6,724
Total		7,148			7,148
Accumulated Depreciation		$ (698)			(698)
Date of Construction or Acquisition		2011
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 7,148
Deductions during year [Abstract]
Balance at close of year		698
Commercial Healthcare [Member] | Spring Creek-Overland - Overland, ID [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				3,106
Initial Cost to Company [Abstract]
Land					687
Buildings & Improvements					5,942
Costs capitalized subsequent to acquisition					0
Gross amount at which carried at close of period [Abstract]
Land					687
Buildings & Improvements					5,942
Total		6,629			6,629
Accumulated Depreciation		$ (644)			(644)
Date of Construction or Acquisition		2011
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 6,629
Deductions during year [Abstract]
Balance at close of year		644
Commercial Healthcare [Member] | Spring Creek-Soda Springs - Soda Springs, ID [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				751
Initial Cost to Company [Abstract]
Land					66
Buildings & Improvements					2,124
Costs capitalized subsequent to acquisition					33
Gross amount at which carried at close of period [Abstract]
Land					66
Buildings & Improvements					2,157
Total		2,223			2,223
Accumulated Depreciation		$ (228)			(228)
Date of Construction or Acquisition		2011
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 2,223
Deductions during year [Abstract]
Balance at close of year		228
Commercial Healthcare [Member] | Spring Creek-Ustick - Meridian, ID [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					467
Buildings & Improvements					3,833
Costs capitalized subsequent to acquisition					0
Gross amount at which carried at close of period [Abstract]
Land					467
Buildings & Improvements					3,833
Total		4,300			4,300
Accumulated Depreciation		$ (370)			(370)
Date of Construction or Acquisition		2011
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 4,300
Deductions during year [Abstract]
Balance at close of year		370
Commercial Healthcare [Member] | St Michael Clinic - St Michael, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				1,795
Initial Cost to Company [Abstract]
Land					328
Buildings & Improvements					2,259
Costs capitalized subsequent to acquisition					264
Gross amount at which carried at close of period [Abstract]
Land					328
Buildings & Improvements					2,523
Total		2,851			2,851
Accumulated Depreciation		$ (510)			(510)
Date of Construction or Acquisition		2007
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 2,851
Deductions during year [Abstract]
Balance at close of year		510
Commercial Healthcare [Member] | Trinity at Plaza 16 - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				4,718
Initial Cost to Company [Abstract]
Land					568
Buildings & Improvements					9,009
Costs capitalized subsequent to acquisition					125
Gross amount at which carried at close of period [Abstract]
Land					674
Buildings & Improvements					9,028
Total		9,702			9,702
Accumulated Depreciation		$ (820)			(820)
Date of Construction or Acquisition		2011
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 9,702
Deductions during year [Abstract]
Balance at close of year		820
Commercial Healthcare [Member] | Wells Clinic - Hibbing, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				1,263
Initial Cost to Company [Abstract]
Land					162
Buildings & Improvements					2,497
Costs capitalized subsequent to acquisition					2
Gross amount at which carried at close of period [Abstract]
Land					162
Buildings & Improvements					2,499
Total		2,661			2,661
Accumulated Depreciation		$ (690)			(690)
Date of Construction or Acquisition		2004
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 2,661
Deductions during year [Abstract]
Balance at close of year		690
Commercial Healthcare [Member] | Wholly Owned Properties [Member]
Reconciliations of total real estate carrying value [Abstract]
Additions		0	18,005	11,122
Industrial [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				12,404
Initial Cost to Company [Abstract]
Land					9,040
Buildings & Improvements					43,081
Costs capitalized subsequent to acquisition					8,490
Gross amount at which carried at close of period [Abstract]
Land					9,336
Buildings & Improvements					51,275
Total		60,611			60,611
Accumulated Depreciation		(11,256)			(11,256)
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		60,611
Deductions during year [Abstract]
Balance at close of year		11,256
Industrial [Member] | Bloomington 2000 W 94th Street - Bloomington, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1],[6]				0
Initial Cost to Company [Abstract]
Land	[6]				2,133
Buildings & Improvements	[6]				4,097
Costs capitalized subsequent to acquisition	[6]				1,217
Gross amount at which carried at close of period [Abstract]
Land	[6]				2,204
Buildings & Improvements	[6]				5,243
Total	[6]	7,447			7,447
Accumulated Depreciation	[6]	$ (1,423)			(1,423)
Date of Construction or Acquisition	[6]	2006
Life on which depreciation in latest income statement is computed	[6]	40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year	[6]	$ 7,447
Deductions during year [Abstract]
Balance at close of year	[6]	1,423
Industrial [Member] | Lexington Commerce Center - Eagan, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				1,604
Initial Cost to Company [Abstract]
Land					453
Buildings & Improvements					4,352
Costs capitalized subsequent to acquisition					1,977
Gross amount at which carried at close of period [Abstract]
Land					480
Buildings & Improvements					6,302
Total		6,782			6,782
Accumulated Depreciation		$ (2,831)			(2,831)
Date of Construction or Acquisition		1999
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 6,782
Deductions during year [Abstract]
Balance at close of year		2,831
Industrial [Member] | Minot IPS - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1],[6]				0
Initial Cost to Company [Abstract]
Land	[6]				416
Buildings & Improvements	[6]				5,952
Costs capitalized subsequent to acquisition	[6]				0
Gross amount at which carried at close of period [Abstract]
Land	[6]				416
Buildings & Improvements	[6]				5,952
Total	[6]	6,368			6,368
Accumulated Depreciation	[6]	$ (374)			(374)
Date of Construction or Acquisition	[6]	2012
Life on which depreciation in latest income statement is computed	[6]	40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year	[6]	$ 6,368
Deductions during year [Abstract]
Balance at close of year	[6]	374
Industrial [Member] | Stone Container - Fargo, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				382
Initial Cost to Company [Abstract]
Land					440
Buildings & Improvements					6,597
Costs capitalized subsequent to acquisition					104
Gross amount at which carried at close of period [Abstract]
Land					440
Buildings & Improvements					6,701
Total		7,141			7,141
Accumulated Depreciation		$ (2,943)			(2,943)
Date of Construction or Acquisition		2001
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 7,141
Deductions during year [Abstract]
Balance at close of year		2,943
Industrial [Member] | Roseville 3075 Long Lake Road - Roseville, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					810
Buildings & Improvements					9,562
Costs capitalized subsequent to acquisition					1,326
Gross amount at which carried at close of period [Abstract]
Land					810
Buildings & Improvements					10,888
Total		11,698			11,698
Accumulated Depreciation		$ (145)			(145)
Date of Construction or Acquisition		2001
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 11,698
Deductions during year [Abstract]
Balance at close of year		145
Industrial [Member] | Urbandale 3900 106th Street - Urbandale, IA [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				10,418
Initial Cost to Company [Abstract]
Land					3,680
Buildings & Improvements					9,893
Costs capitalized subsequent to acquisition					1,982
Gross amount at which carried at close of period [Abstract]
Land					3,863
Buildings & Improvements					11,692
Total		15,555			15,555
Accumulated Depreciation		$ (2,553)			(2,553)
Date of Construction or Acquisition		2007
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 15,555
Deductions during year [Abstract]
Balance at close of year		2,553
Industrial [Member] | Woodbury 1865 Woodlane - Woodbury, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					1,108
Buildings & Improvements					2,628
Costs capitalized subsequent to acquisition					1,884
Gross amount at which carried at close of period [Abstract]
Land					1,123
Buildings & Improvements					4,497
Total		5,620			5,620
Accumulated Depreciation		$ (987)			(987)
Date of Construction or Acquisition		2007
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 5,620
Deductions during year [Abstract]
Balance at close of year		987
Industrial [Member] | Wholly Owned Properties [Member]
Reconciliations of total real estate carrying value [Abstract]
Additions		9,037	0	5,900
Retail [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				26,687
Initial Cost to Company [Abstract]
Land					17,147
Buildings & Improvements					73,933
Costs capitalized subsequent to acquisition					20,849
Gross amount at which carried at close of period [Abstract]
Land					19,443
Buildings & Improvements					92,486
Total		111,929			111,929
Accumulated Depreciation		(28,545)			(28,545)
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		111,929
Deductions during year [Abstract]
Balance at close of year		28,545
Retail [Member] | 17 South Main - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				75
Initial Cost to Company [Abstract]
Land					15
Buildings & Improvements					75
Costs capitalized subsequent to acquisition					197
Gross amount at which carried at close of period [Abstract]
Land					17
Buildings & Improvements					270
Total		287			287
Accumulated Depreciation		$ (202)			(202)
Date of Construction or Acquisition		2000
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 287
Deductions during year [Abstract]
Balance at close of year		202
Retail [Member] | Arrowhead First International Bank - Minot ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					75
Buildings & Improvements					1,211
Costs capitalized subsequent to acquisition					20
Gross amount at which carried at close of period [Abstract]
Land					95
Buildings & Improvements					1,211
Total		1,306			1,306
Accumulated Depreciation		$ (65)			(65)
Date of Construction or Acquisition		2013
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 1,306
Deductions during year [Abstract]
Balance at close of year		65
Retail [Member] | Burnsville 1 Strip Center - Burnsville, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					208
Buildings & Improvements					773
Costs capitalized subsequent to acquisition					200
Gross amount at which carried at close of period [Abstract]
Land					208
Buildings & Improvements					973
Total		1,181			1,181
Accumulated Depreciation		$ (306)			(306)
Date of Construction or Acquisition		2003
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 1,181
Deductions during year [Abstract]
Balance at close of year		306
Retail [Member] | Champlin South Pond - Champlin, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				1,185
Initial Cost to Company [Abstract]
Land					842
Buildings & Improvements					2,703
Costs capitalized subsequent to acquisition					105
Gross amount at which carried at close of period [Abstract]
Land					866
Buildings & Improvements					2,784
Total		3,650			3,650
Accumulated Depreciation		$ (797)			(797)
Date of Construction or Acquisition		2004
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 3,650
Deductions during year [Abstract]
Balance at close of year		797
Retail [Member] | Chan West Village - Chanhassen, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				12,307
Initial Cost to Company [Abstract]
Land					5,035
Buildings & Improvements					14,665
Costs capitalized subsequent to acquisition					2,079
Gross amount at which carried at close of period [Abstract]
Land					5,679
Buildings & Improvements					16,100
Total		21,779			21,779
Accumulated Depreciation		$ (5,215)			(5,215)
Date of Construction or Acquisition		2003
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 21,779
Deductions during year [Abstract]
Balance at close of year		5,215
Retail [Member] | Dakota West Plaza - Minot , ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				347
Initial Cost to Company [Abstract]
Land					92
Buildings & Improvements					493
Costs capitalized subsequent to acquisition					30
Gross amount at which carried at close of period [Abstract]
Land					106
Buildings & Improvements					509
Total		615			615
Accumulated Depreciation		$ (122)			(122)
Date of Construction or Acquisition		2006
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 615
Deductions during year [Abstract]
Balance at close of year		122
Retail [Member] | Duluth 4615 Grand - Duluth, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				544
Initial Cost to Company [Abstract]
Land					130
Buildings & Improvements					1,800
Costs capitalized subsequent to acquisition					156
Gross amount at which carried at close of period [Abstract]
Land					131
Buildings & Improvements					1,955
Total		2,086			2,086
Accumulated Depreciation		$ (499)			(499)
Date of Construction or Acquisition		2004
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 2,086
Deductions during year [Abstract]
Balance at close of year		499
Retail [Member] | Duluth Denfeld Retail - Duluth, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				1,798
Initial Cost to Company [Abstract]
Land					276
Buildings & Improvements					4,699
Costs capitalized subsequent to acquisition					185
Gross amount at which carried at close of period [Abstract]
Land					297
Buildings & Improvements					4,863
Total		5,160			5,160
Accumulated Depreciation		$ (1,380)			(1,380)
Date of Construction or Acquisition		2004
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 5,160
Deductions during year [Abstract]
Balance at close of year		1,380
Retail [Member] | Forest Lake Auto - Forest Lake, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					50
Buildings & Improvements					446
Costs capitalized subsequent to acquisition					13
Gross amount at which carried at close of period [Abstract]
Land					50
Buildings & Improvements					459
Total		509			509
Accumulated Depreciation		$ (143)			(143)
Date of Construction or Acquisition		2003
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 509
Deductions during year [Abstract]
Balance at close of year		143
Retail [Member] | Forest Lake Westlake Center - Forest Lake, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					2,446
Buildings & Improvements					5,304
Costs capitalized subsequent to acquisition					1,747
Gross amount at which carried at close of period [Abstract]
Land					2,480
Buildings & Improvements					7,017
Total		9,497			9,497
Accumulated Depreciation		$ (1,830)			(1,830)
Date of Construction or Acquisition		2003
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 9,497
Deductions during year [Abstract]
Balance at close of year		1,830
Retail [Member] | Grand Forks Carmike - Grand Forks, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				1,304
Initial Cost to Company [Abstract]
Land					184
Buildings & Improvements					2,360
Costs capitalized subsequent to acquisition					2
Gross amount at which carried at close of period [Abstract]
Land					184
Buildings & Improvements					2,362
Total		2,546			2,546
Accumulated Depreciation		$ (1,211)			(1,211)
Date of Construction or Acquisition		1994
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 2,546
Deductions during year [Abstract]
Balance at close of year		1,211
Retail [Member] | Grand Forks Medpark Mall - Grand Forks, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					681
Buildings & Improvements					4,808
Costs capitalized subsequent to acquisition					231
Gross amount at which carried at close of period [Abstract]
Land					722
Buildings & Improvements					4,998
Total		5,720			5,720
Accumulated Depreciation		$ (1,924)			(1,924)
Date of Construction or Acquisition		2000
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 5,720
Deductions during year [Abstract]
Balance at close of year		1,924
Retail [Member] | Jamestown Buffalo Mall - Jamestown, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				1,717
Initial Cost to Company [Abstract]
Land					566
Buildings & Improvements					5,551
Costs capitalized subsequent to acquisition					2,975
Gross amount at which carried at close of period [Abstract]
Land					1,114
Buildings & Improvements					7,978
Total		9,092			9,092
Accumulated Depreciation		$ (1,996)			(1,996)
Date of Construction or Acquisition		2003
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 9,092
Deductions during year [Abstract]
Balance at close of year		1,996
Retail [Member] | Jamestown Business Center - Jamestown, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				327
Initial Cost to Company [Abstract]
Land					297
Buildings & Improvements					1,023
Costs capitalized subsequent to acquisition					1,312
Gross amount at which carried at close of period [Abstract]
Land					333
Buildings & Improvements					2,299
Total		2,632			2,632
Accumulated Depreciation		$ (965)			(965)
Date of Construction or Acquisition		2003
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 2,632
Deductions during year [Abstract]
Balance at close of year		965
Retail [Member] | Lakeville Strip Center - Lakeville, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					46
Buildings & Improvements					1,142
Costs capitalized subsequent to acquisition					955
Gross amount at which carried at close of period [Abstract]
Land					94
Buildings & Improvements					2,049
Total		2,143			2,143
Accumulated Depreciation		$ (726)			(726)
Date of Construction or Acquisition		2003
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 2,143
Deductions during year [Abstract]
Balance at close of year		726
Retail [Member] | Minot Arrowhead - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1],[6]				0
Initial Cost to Company [Abstract]
Land	[6]				100
Buildings & Improvements	[6]				3,216
Costs capitalized subsequent to acquisition	[6]				5,553
Gross amount at which carried at close of period [Abstract]
Land	[6]				176
Buildings & Improvements	[6]				8,693
Total	[6]	8,869			8,869
Accumulated Depreciation	[6]	$ (2,058)			(2,058)
Date of Construction or Acquisition	[6]	1973
Life on which depreciation in latest income statement is computed	[6]	40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year	[6]	$ 8,869
Deductions during year [Abstract]
Balance at close of year	[6]	2,058
Retail [Member] | Minot Plaza - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				758
Initial Cost to Company [Abstract]
Land					50
Buildings & Improvements					453
Costs capitalized subsequent to acquisition					155
Gross amount at which carried at close of period [Abstract]
Land					80
Buildings & Improvements					578
Total		658			658
Accumulated Depreciation		$ (339)			(339)
Date of Construction or Acquisition		1993
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 658
Deductions during year [Abstract]
Balance at close of year		339
Retail [Member] | Minot Southgate Wells Fargo Bank - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					992
Buildings & Improvements					2,194
Costs capitalized subsequent to acquisition					0
Gross amount at which carried at close of period [Abstract]
Land					992
Buildings & Improvements					2,194
Total		3,186			3,186
Accumulated Depreciation		$ (24)			(24)
Date of Construction or Acquisition		2014
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 3,186
Deductions during year [Abstract]
Balance at close of year		24
Retail [Member] | Monticello C Store - Monticello, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					65
Buildings & Improvements					770
Costs capitalized subsequent to acquisition					37
Gross amount at which carried at close of period [Abstract]
Land					97
Buildings & Improvements					775
Total		872			872
Accumulated Depreciation		$ (247)			(247)
Date of Construction or Acquisition		2003
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 872
Deductions during year [Abstract]
Balance at close of year		247
Retail [Member] | Omaha Barnes & Noble - Omaha, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					600
Buildings & Improvements					3,099
Costs capitalized subsequent to acquisition					0
Gross amount at which carried at close of period [Abstract]
Land					600
Buildings & Improvements					3,099
Total		3,699			3,699
Accumulated Depreciation		$ (1,511)			(1,511)
Date of Construction or Acquisition		1995
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 3,699
Deductions during year [Abstract]
Balance at close of year		1,511
Retail [Member] | Pine City C-Store - Pine City, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					83
Buildings & Improvements					357
Costs capitalized subsequent to acquisition					12
Gross amount at which carried at close of period [Abstract]
Land					83
Buildings & Improvements					369
Total		452			452
Accumulated Depreciation		$ (118)			(118)
Date of Construction or Acquisition		2003
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 452
Deductions during year [Abstract]
Balance at close of year		118
Retail [Member] | Pine City Evergreen Square - Pine City, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					154
Buildings & Improvements					2,646
Costs capitalized subsequent to acquisition					1,334
Gross amount at which carried at close of period [Abstract]
Land					385
Buildings & Improvements					3,749
Total		4,134			4,134
Accumulated Depreciation		$ (1,104)			(1,104)
Date of Construction or Acquisition		2003
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 4,134
Deductions during year [Abstract]
Balance at close of year		1,104
Retail [Member] | Rochester Maplewood Square - Rochester, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				6,325
Initial Cost to Company [Abstract]
Land					3,275
Buildings & Improvements					8,610
Costs capitalized subsequent to acquisition					2,155
Gross amount at which carried at close of period [Abstract]
Land					3,652
Buildings & Improvements					10,388
Total		14,040			14,040
Accumulated Depreciation		$ (3,936)			(3,936)
Date of Construction or Acquisition		1999
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 14,040
Deductions during year [Abstract]
Balance at close of year		3,936
Retail [Member] | St. Cloud Westgate - St. Cloud, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				0
Initial Cost to Company [Abstract]
Land					885
Buildings & Improvements					5,535
Costs capitalized subsequent to acquisition					1,396
Gross amount at which carried at close of period [Abstract]
Land					1,002
Buildings & Improvements					6,814
Total		7,816			7,816
Accumulated Depreciation		$ (1,827)			(1,827)
Date of Construction or Acquisition		2004
Life on which depreciation in latest income statement is computed		40 years
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		$ 7,816
Deductions during year [Abstract]
Balance at close of year		1,827
Retail [Member] | Wholly Owned Properties [Member]
Reconciliations of total real estate carrying value [Abstract]
Additions		3,186	$ 0	$ 1,240
Subtotal [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	[1]				963,222
Initial Cost to Company [Abstract]
Land					187,840
Buildings & Improvements					1,628,789
Costs capitalized subsequent to acquisition					281,408
Gross amount at which carried at close of period [Abstract]
Land					209,937
Buildings & Improvements					1,888,100
Total		2,098,037			2,098,037
Accumulated Depreciation		(448,987)			$ (448,987)
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year		2,098,037
Deductions during year [Abstract]
Balance at close of year		$ 448,987

[1] Amounts in this column are the mortgages payable balances as of April 30, 2015. These amounts do not include amounts owing under the Company's multi-bank line of credit or under the Company's construction loans.

[2] The net basis of the Company's real estate investments for Federal Income Tax purposes was $1.7 billion, $1.5 billion and $1.5 billion at April 30, 2015, 2014 and 2013, respectively.

[3] Consists of miscellaneous disposed assets.

[4] Includes development projects that are placed in service in phases.

[5] Consists of miscellaneous re-classed assets.

[6] As of April 30, 2015, this property was included in the collateral pool securing the Company's $90.0 million multi-bank line of credit. The Company may add and remove eligible properties from the collateral pool if certain minimum collateral requirements are satisfied. Advances under the facility may not exceed 60% of the value of properties provided as security.