SCHEDULE III - REAL ESTATE AND ACCUMULATED DEPRECIATION (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2016	Apr. 30, 2015	Apr. 30, 2014	Apr. 30, 2016	Apr. 30, 2015	Apr. 30, 2014
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				$ 817,074
Initial Cost to Company [Abstract]
Land				138,997
Buildings & Improvements				1,382,158
Costs capitalized subsequent to acquisition				232,936
Gross amount at which carried at close of period [Abstract]
Land				161,153
Buildings & Improvements				1,592,938
Total	$ 1,754,091			1,754,091
Accumulated Depreciation	$ (279,417)	$ (273,934)	$ (266,212)	(312,889)	$ (279,417)	$ (273,934)
Maximum borrowing capacity				100,000
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]
Write down of asset and accumulated depreciation on impaired assets		(881)	(6,291)
Balance at close of year	$ 1,754,091
Reconciliations of accumulated depreciation/amortization [Abstract]
Balance at beginning of year	279,417	273,934	266,212
Additions during year [Abstract]
Provisions for depreciation	47,064	40,078	35,391
Deductions during year [Abstract]
Accumulated depreciation on real estate sold	(9,957)	(29,463)	(19,413)
Write down of asset and accumulated depreciation on impaired assets		(881)	(6,291)
Other	(3,635)	(4,251)	(1,965)
Balance at close of year	312,889	279,417	273,934
Total real estate investments				1,441,202	1,236,091
Net basis of real estate investments for federal income tax purposes				1,600	1,700	1,500
Discontinued Operations [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				68,824
Initial Cost to Company [Abstract]
Land				14,717
Buildings & Improvements				207,937
Costs capitalized subsequent to acquisition				43,873
Gross amount at which carried at close of period [Abstract]
Land				14,824
Buildings & Improvements				251,703
Total	266,527			266,527
Accumulated Depreciation	(59,137)			(59,137)
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year	266,527
Deductions during year [Abstract]
Balance at close of year	59,137
Discontinued Operations [Member] | Casper 1930 E 12th Street (Park Place) - Casper, WY [Member]
Initial Cost to Company [Abstract]
Land				439
Buildings & Improvements				5,780
Costs capitalized subsequent to acquisition				1,296
Gross amount at which carried at close of period [Abstract]
Land				439
Buildings & Improvements				7,076
Total	7,515			7,515
Accumulated Depreciation	$ (1,374)			(1,374)
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	$ 7,515
Deductions during year [Abstract]
Balance at close of year	1,374
Discontinued Operations [Member] | Casper 3955 E 12th Street (Meadow Wind) - Casper, WY [Member]
Initial Cost to Company [Abstract]
Land				388
Buildings & Improvements				10,494
Costs capitalized subsequent to acquisition				1,700
Gross amount at which carried at close of period [Abstract]
Land				459
Buildings & Improvements				12,123
Total	12,582			12,582
Accumulated Depreciation	$ (2,263)			(2,263)
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	$ 12,582
Deductions during year [Abstract]
Balance at close of year	2,263
Discontinued Operations [Member] | Cheyenne 4010 N College Drive (Aspen Wind) - Cheyenne, WY [Member]
Initial Cost to Company [Abstract]
Land				628
Buildings & Improvements				10,272
Costs capitalized subsequent to acquisition				2,243
Gross amount at which carried at close of period [Abstract]
Land				629
Buildings & Improvements				12,514
Total	13,143			13,143
Accumulated Depreciation	$ (2,360)			(2,360)
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	$ 13,143
Deductions during year [Abstract]
Balance at close of year	2,360
Discontinued Operations [Member] | Cheyenne 4606 N College Drive (Sierra Hills) - Cheyenne, WY [Member]
Initial Cost to Company [Abstract]
Land				695
Buildings & Improvements				7,455
Costs capitalized subsequent to acquisition				1,468
Gross amount at which carried at close of period [Abstract]
Land				695
Buildings & Improvements				8,923
Total	9,618			9,618
Accumulated Depreciation	$ (1,661)			(1,661)
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	$ 9,618
Deductions during year [Abstract]
Balance at close of year	1,661
Discontinued Operations [Member] | Edgewood Vista - Belgrade, MT [Member]
Initial Cost to Company [Abstract]
Land				35
Buildings & Improvements				779
Costs capitalized subsequent to acquisition				1,129
Gross amount at which carried at close of period [Abstract]
Land				35
Buildings & Improvements				1,908
Total	1,943			1,943
Accumulated Depreciation	$ (663)			(663)
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	$ 1,943
Deductions during year [Abstract]
Balance at close of year	663
Discontinued Operations [Member] | Edgewood Vista - Billings, MT [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				1,723
Initial Cost to Company [Abstract]
Land				115
Buildings & Improvements				1,767
Costs capitalized subsequent to acquisition				2,033
Gross amount at which carried at close of period [Abstract]
Land				115
Buildings & Improvements				3,800
Total	3,915			3,915
Accumulated Depreciation	$ (1,276)			(1,276)
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	$ 3,915
Deductions during year [Abstract]
Balance at close of year	1,276
Discontinued Operations [Member] | Edgewood Vista - Bismarck, ND [Member]
Initial Cost to Company [Abstract]
Land				511
Buildings & Improvements				9,193
Costs capitalized subsequent to acquisition				1,018
Gross amount at which carried at close of period [Abstract]
Land				511
Buildings & Improvements				10,211
Total	10,722			10,722
Accumulated Depreciation	$ (2,829)			(2,829)
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	$ 10,722
Deductions during year [Abstract]
Balance at close of year	2,829
Discontinued Operations [Member] | Edgewood Vista - Brainerd, MN [Member]
Initial Cost to Company [Abstract]
Land				587
Buildings & Improvements				8,999
Costs capitalized subsequent to acquisition				916
Gross amount at which carried at close of period [Abstract]
Land				587
Buildings & Improvements				9,915
Total	10,502			10,502
Accumulated Depreciation	$ (2,760)			(2,760)
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	$ 10,502
Deductions during year [Abstract]
Balance at close of year	2,760
Discontinued Operations [Member] | Edgewood Vista - Columbus, NE [Member]
Initial Cost to Company [Abstract]
Land				43
Buildings & Improvements				824
Costs capitalized subsequent to acquisition				531
Gross amount at which carried at close of period [Abstract]
Land				44
Buildings & Improvements				1,354
Total	1,398			1,398
Accumulated Depreciation	$ (404)			(404)
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	$ 1,398
Deductions during year [Abstract]
Balance at close of year	404
Discontinued Operations [Member] | Edgewood Vista - East Grand Forks, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				2,625
Initial Cost to Company [Abstract]
Land				290
Buildings & Improvements				1,352
Costs capitalized subsequent to acquisition				2,864
Gross amount at which carried at close of period [Abstract]
Land				290
Buildings & Improvements				4,216
Total	4,506			4,506
Accumulated Depreciation	$ (1,557)			(1,557)
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	$ 4,506
Deductions during year [Abstract]
Balance at close of year	1,557
Discontinued Operations [Member] | Edgewood Vista - Fargo, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				11,297
Initial Cost to Company [Abstract]
Land				775
Buildings & Improvements				20,870
Costs capitalized subsequent to acquisition				4,032
Gross amount at which carried at close of period [Abstract]
Land				775
Buildings & Improvements				24,902
Total	25,677			25,677
Accumulated Depreciation	$ (5,964)			(5,964)
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	$ 25,677
Deductions during year [Abstract]
Balance at close of year	5,964
Discontinued Operations [Member] | Edgewood Vista - Fremont, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				528
Initial Cost to Company [Abstract]
Land				56
Buildings & Improvements				490
Costs capitalized subsequent to acquisition				59
Gross amount at which carried at close of period [Abstract]
Land				56
Buildings & Improvements				549
Total	605			605
Accumulated Depreciation	$ (193)			(193)
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	$ 605
Deductions during year [Abstract]
Balance at close of year	193
Discontinued Operations [Member] | Edgewood Vista - Grand Island, NE [Member]
Initial Cost to Company [Abstract]
Land				33
Buildings & Improvements				773
Costs capitalized subsequent to acquisition				540
Gross amount at which carried at close of period [Abstract]
Land				39
Buildings & Improvements				1,307
Total	1,346			1,346
Accumulated Depreciation	$ (400)			(400)
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	400
Discontinued Operations [Member] | Edgewood Vista - Hastings, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				544
Initial Cost to Company [Abstract]
Land				49
Buildings & Improvements				517
Costs capitalized subsequent to acquisition				62
Gross amount at which carried at close of period [Abstract]
Land				50
Buildings & Improvements				578
Total	628			628
Accumulated Depreciation	$ (213)			(213)
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	$ 628
Deductions during year [Abstract]
Balance at close of year	213
Discontinued Operations [Member] | Edgewood Vista - Hermantown I, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				14,576
Initial Cost to Company [Abstract]
Land				288
Buildings & Improvements				9,871
Costs capitalized subsequent to acquisition				10,094
Gross amount at which carried at close of period [Abstract]
Land				288
Buildings & Improvements				19,965
Total	20,253			20,253
Accumulated Depreciation	$ (7,931)			(7,931)
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	$ 20,253
Deductions during year [Abstract]
Balance at close of year	7,931
Discontinued Operations [Member] | Edgewood Vista - Hermantown II, MN [Member]
Initial Cost to Company [Abstract]
Land				719
Buildings & Improvements				10,517
Costs capitalized subsequent to acquisition				942
Gross amount at which carried at close of period [Abstract]
Land				719
Buildings & Improvements				11,459
Total	12,178			12,178
Accumulated Depreciation	$ (3,168)			(3,168)
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	$ 12,178
Deductions during year [Abstract]
Balance at close of year	3,168
Discontinued Operations [Member] | Edgewood Vista - Kalispell, MT [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				545
Initial Cost to Company [Abstract]
Land				70
Buildings & Improvements				502
Costs capitalized subsequent to acquisition				625
Gross amount at which carried at close of period [Abstract]
Land				70
Buildings & Improvements				1,127
Total	1,197			1,197
Accumulated Depreciation	$ (442)			(442)
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	$ 1,197
Deductions during year [Abstract]
Balance at close of year	442
Discontinued Operations [Member] | Edgewood Vista - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				8,768
Initial Cost to Company [Abstract]
Land				1,045
Buildings & Improvements				11,590
Costs capitalized subsequent to acquisition				2,805
Gross amount at which carried at close of period [Abstract]
Land				1,047
Buildings & Improvements				14,393
Total	15,440			15,440
Accumulated Depreciation	$ (3,000)			(3,000)
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	$ 15,440
Deductions during year [Abstract]
Balance at close of year	3,000
Discontinued Operations [Member] | Edgewood Vista - Missoula, MT [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				774
Initial Cost to Company [Abstract]
Land				109
Buildings & Improvements				854
Costs capitalized subsequent to acquisition				72
Gross amount at which carried at close of period [Abstract]
Land				116
Buildings & Improvements				919
Total	1,035			1,035
Accumulated Depreciation	$ (439)			(439)
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	$ 1,035
Deductions during year [Abstract]
Balance at close of year	439
Discontinued Operations [Member] | Edgewood Vista - Norfolk, NE [Member]
Initial Cost to Company [Abstract]
Land				42
Buildings & Improvements				722
Costs capitalized subsequent to acquisition				494
Gross amount at which carried at close of period [Abstract]
Land				42
Buildings & Improvements				1,216
Total	1,258			1,258
Accumulated Depreciation	$ (366)			(366)
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	$ 1,258
Deductions during year [Abstract]
Balance at close of year	366
Discontinued Operations [Member] | Edgewood Vista - Omaha, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				345
Initial Cost to Company [Abstract]
Land				89
Buildings & Improvements				547
Costs capitalized subsequent to acquisition				55
Gross amount at which carried at close of period [Abstract]
Land				89
Buildings & Improvements				602
Total	691			691
Accumulated Depreciation	$ (218)			(218)
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	$ 691
Deductions during year [Abstract]
Balance at close of year	218
Discontinued Operations [Member] | Edgewood Vista - Sioux Falls, SD [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				987
Initial Cost to Company [Abstract]
Land				314
Buildings & Improvements				974
Costs capitalized subsequent to acquisition				1,754
Gross amount at which carried at close of period [Abstract]
Land				314
Buildings & Improvements				2,728
Total	3,042			3,042
Accumulated Depreciation	$ (993)			(993)
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	$ 3,042
Deductions during year [Abstract]
Balance at close of year	993
Discontinued Operations [Member] | Edgewood Vista - Spearfish, SD [Member]
Initial Cost to Company [Abstract]
Land				315
Buildings & Improvements				8,584
Costs capitalized subsequent to acquisition				664
Gross amount at which carried at close of period [Abstract]
Land				330
Buildings & Improvements				9,233
Total	9,563			9,563
Accumulated Depreciation	$ (2,144)			(2,144)
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	$ 9,563
Deductions during year [Abstract]
Balance at close of year	2,144
Discontinued Operations [Member] | Edgewood Vista - Virginia, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				12,399
Initial Cost to Company [Abstract]
Land				246
Buildings & Improvements				11,823
Costs capitalized subsequent to acquisition				4,581
Gross amount at which carried at close of period [Abstract]
Land				246
Buildings & Improvements				16,404
Total	16,650			16,650
Accumulated Depreciation	$ (5,886)			(5,886)
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	$ 16,650
Deductions during year [Abstract]
Balance at close of year	5,886
Discontinued Operations [Member] | Georgetown Square - Grand Chute, WI [Member]
Initial Cost to Company [Abstract]
Land				250
Gross amount at which carried at close of period [Abstract]
Land				250
Total	$ 250			250
Date of Construction or Acquisition	2006
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year	$ 250
Discontinued Operations [Member] | Laramie 1072 N 22nd Street (Spring Wind) - Laramie, WY [Member]
Initial Cost to Company [Abstract]
Land				406
Buildings & Improvements				10,151
Costs capitalized subsequent to acquisition				1,296
Gross amount at which carried at close of period [Abstract]
Land				406
Buildings & Improvements				11,447
Total	11,853			11,853
Accumulated Depreciation	$ (1,964)			(1,964)
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	$ 11,853
Deductions during year [Abstract]
Balance at close of year	1,964
Discontinued Operations [Member] | Legends at Heritage Place - Sartell, MN [Member]
Initial Cost to Company [Abstract]
Land				970
Buildings & Improvements				9,920
Gross amount at which carried at close of period [Abstract]
Land				970
Buildings & Improvements				9,920
Total	10,890			10,890
Accumulated Depreciation	$ (630)			(630)
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	630
Discontinued Operations [Member] | Legends at Heritage Place - Sartell, MN, Unimproved Land [Member]
Initial Cost to Company [Abstract]
Land				537
Gross amount at which carried at close of period [Abstract]
Land				537
Total	$ 537			537
Date of Construction or Acquisition	2013
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year	$ 537
Discontinued Operations [Member] | Pinecone Villas - Sartell, MN [Member]
Initial Cost to Company [Abstract]
Land				584
Buildings & Improvements				2,191
Costs capitalized subsequent to acquisition				47
Gross amount at which carried at close of period [Abstract]
Land				587
Buildings & Improvements				2,235
Total	2,822			2,822
Accumulated Depreciation	$ (159)			(159)
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	$ 2,822
Deductions during year [Abstract]
Balance at close of year	159
Discontinued Operations [Member] | Sartell 2000 23rd Street South - Sartell, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				662
Initial Cost to Company [Abstract]
Buildings & Improvements				6,400
Gross amount at which carried at close of period [Abstract]
Buildings & Improvements				6,400
Total	$ 6,400			6,400
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	$ 6,400
Discontinued Operations [Member] | Spring Creek American Falls American Falls ID [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				1,955
Initial Cost to Company [Abstract]
Land				145
Buildings & Improvements				3,870
Costs capitalized subsequent to acquisition				55
Gross amount at which carried at close of period [Abstract]
Land				145
Buildings & Improvements				3,925
Total	4,070			4,070
Accumulated Depreciation	$ (542)			(542)
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	$ 4,070
Deductions during year [Abstract]
Balance at close of year	542
Discontinued Operations [Member] | Spring Creek-Boise - Boise, ID [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				2,640
Initial Cost to Company [Abstract]
Land				708
Buildings & Improvements				4,296
Costs capitalized subsequent to acquisition				71
Gross amount at which carried at close of period [Abstract]
Land				708
Buildings & Improvements				4,367
Total	5,075			5,075
Accumulated Depreciation	$ (649)			(649)
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	$ 5,075
Deductions during year [Abstract]
Balance at close of year	649
Discontinued Operations [Member] | Spring Creek-Eagle - Eagle, ID [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				1,799
Initial Cost to Company [Abstract]
Land				263
Buildings & Improvements				3,775
Costs capitalized subsequent to acquisition				62
Gross amount at which carried at close of period [Abstract]
Land				263
Buildings & Improvements				3,837
Total	4,100			4,100
Accumulated Depreciation	$ (534)			(534)
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	$ 4,100
Deductions during year [Abstract]
Balance at close of year	534
Discontinued Operations [Member] | Spring Creek Fruitland - Fruitland, ID [Member]
Initial Cost to Company [Abstract]
Land				550
Buildings & Improvements				6,565
Gross amount at which carried at close of period [Abstract]
Land				550
Buildings & Improvements				6,565
Total	7,115			7,115
Accumulated Depreciation	$ (462)			(462)
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	462
Discontinued Operations [Member] | Spring Creek Fruitland - Fruitland, ID, Unimproved Land [Member]
Initial Cost to Company [Abstract]
Land				339
Gross amount at which carried at close of period [Abstract]
Land				339
Total	$ 339			339
Date of Construction or Acquisition	2014
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year	$ 339
Discontinued Operations [Member] | Spring Creek-Meridian - Meridian, ID [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				2,972
Initial Cost to Company [Abstract]
Land				424
Buildings & Improvements				6,724
Costs capitalized subsequent to acquisition				102
Gross amount at which carried at close of period [Abstract]
Land				424
Buildings & Improvements				6,826
Total	7,250			7,250
Accumulated Depreciation	$ (938)			(938)
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	$ 7,250
Deductions during year [Abstract]
Balance at close of year	938
Discontinued Operations [Member] | Spring Creek-Overland - Overland, ID [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				2,981
Initial Cost to Company [Abstract]
Land				687
Buildings & Improvements				5,942
Costs capitalized subsequent to acquisition				96
Gross amount at which carried at close of period [Abstract]
Land				687
Buildings & Improvements				6,038
Total	6,725			6,725
Accumulated Depreciation	$ (867)			(867)
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	$ 6,725
Deductions during year [Abstract]
Balance at close of year	867
Discontinued Operations [Member] | Spring Creek-Soda Springs - Soda Springs, ID [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				704
Initial Cost to Company [Abstract]
Land				66
Buildings & Improvements				2,124
Costs capitalized subsequent to acquisition				63
Gross amount at which carried at close of period [Abstract]
Land				66
Buildings & Improvements				2,187
Total	2,253			2,253
Accumulated Depreciation	$ (304)			(304)
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	$ 2,253
Deductions during year [Abstract]
Balance at close of year	304
Discontinued Operations [Member] | Spring Creek-Ustick - Meridian, ID [Member]
Initial Cost to Company [Abstract]
Land				467
Buildings & Improvements				3,833
Gross amount at which carried at close of period [Abstract]
Land				467
Buildings & Improvements				3,833
Total	4,300			4,300
Accumulated Depreciation	$ (473)			(473)
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	473
Discontinued Operations [Member] | Stone Container - Fargo, ND [Member]
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	$ (3,111)			(3,111)
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	3,111
Wholly Owned Properties [Member]
Gross amount at which carried at close of period [Abstract]
Total	1,335,687	1,241,195	1,244,860	1,681,471	1,335,687	1,241,195
Reconciliations of total real estate carrying value [Abstract]
Balance at beginning of year	1,335,687	1,241,195	1,244,860
Transfers	(32,438)	(97,824)	(10,307)
Improvements and Other	34,619	21,006	24,317
Total Additions	1,718,991	1,457,538	1,353,294
Cost of real estate sold	(1,305)	(17,904)	(85,029)
Impairment charge		(1,566)	(8,323)
Write down of asset and accumulated depreciation on impaired assets		(881)	(6,291)
Other	(3,777)	(3,676)	(2,149)
Balance at close of year	1,681,471	1,335,687	1,241,195
Deductions during year [Abstract]
Write down of asset and accumulated depreciation on impaired assets		(881)	(6,291)
Development in Progress [Member]
Initial Cost to Company [Abstract]
Land				3,235
Buildings & Improvements				41,887
Costs capitalized subsequent to acquisition				6,559
Gross amount at which carried at close of period [Abstract]
Land				3,235
Buildings & Improvements				48,446
Total	153,994	104,609	46,782	51,681	153,994	104,609
Reconciliations of total real estate carrying value [Abstract]
Balance at beginning of year	153,994	104,609	46,782
Acquisitions		12,647	2,079
Transfers	1,734	7,015	2,870
Improvements and Other	96,753	189,306	123,240
Involuntary conversion			(7,052)
Development placed in service	(200,800)	(159,578)	(63,210)
Other		(5)	(100)
Balance at close of year	51,681	153,994	104,609
Development in Progress [Member] | 71 France - Edina, MN [Member]
Initial Cost to Company [Abstract]
Land				1,501
Buildings & Improvements				28,100
Costs capitalized subsequent to acquisition				814
Gross amount at which carried at close of period [Abstract]
Land				1,501
Buildings & Improvements				28,914
Total	$ 30,415			30,415
Date of Construction or Acquisition	2015
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year	$ 30,415
Development in Progress [Member] | Other [Member]
Initial Cost to Company [Abstract]
Costs capitalized subsequent to acquisition				3,759
Gross amount at which carried at close of period [Abstract]
Buildings & Improvements				3,759
Total	3,759			3,759
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year	3,759
Development in Progress [Member] | Monticello 7th Addition - Monticello, MN [Member]
Initial Cost to Company [Abstract]
Land				1,734
Buildings & Improvements				13,787
Costs capitalized subsequent to acquisition				1,986
Gross amount at which carried at close of period [Abstract]
Land				1,734
Buildings & Improvements				15,773
Total	$ 17,507			17,507
Date of Construction or Acquisition	2015
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year	$ 17,507
Unimproved Land [Member]
Initial Cost to Company [Abstract]
Land				18,478
Costs capitalized subsequent to acquisition				2,461
Gross amount at which carried at close of period [Abstract]
Land				20,939
Total	25,827	22,864	21,503	20,939	25,827	22,864
Reconciliations of total real estate carrying value [Abstract]
Balance at beginning of year	25,827	22,864	21,503
Acquisitions		10,487	3,022
Transfers	(1,632)	(79)
Improvements and Other	205	1,533	1,209
Cost of real estate sold	(442)	(670)
Impairment charge	(1,285)	(1,293)
Development placed in service	(1,734)	(7,015)	(2,870)
Balance at close of year	20,939	25,827	22,864
Deductions during year [Abstract]
Total real estate investments				1,441,202	$ 1,236,091	$ 1,094,734
Unimproved Land [Member] | 288 unit - Renaissance Heights - Williston, ND [Member]
Initial Cost to Company [Abstract]
Land				2,229
Costs capitalized subsequent to acquisition				1,701
Gross amount at which carried at close of period [Abstract]
Land				3,930
Total	$ 3,930			3,930
Date of Construction or Acquisition	2012
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year	$ 3,930
Unimproved Land [Member] | Badger Hills - Rochester, MN [Member]
Initial Cost to Company [Abstract]
Land				1,050
Gross amount at which carried at close of period [Abstract]
Land				1,050
Total	$ 1,050			1,050
Date of Construction or Acquisition	2012
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year	$ 1,050
Unimproved Land [Member] | Bismarck 4916 - Bismarck, ND [Member]
Initial Cost to Company [Abstract]
Land				3,250
Costs capitalized subsequent to acquisition				17
Gross amount at which carried at close of period [Abstract]
Land				3,267
Total	$ 3,267			3,267
Date of Construction or Acquisition	2013
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year	$ 3,267
Unimproved Land [Member] | Bismarck 700 E Main - Bismarck, ND [Member]
Initial Cost to Company [Abstract]
Land				314
Costs capitalized subsequent to acquisition				568
Gross amount at which carried at close of period [Abstract]
Land				882
Total	$ 882			882
Date of Construction or Acquisition	2008
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year	$ 882
Unimproved Land [Member] | Creekside Crossing - Bismarck, ND [Member]
Initial Cost to Company [Abstract]
Land				4,286
Costs capitalized subsequent to acquisition				66
Gross amount at which carried at close of period [Abstract]
Land				4,352
Total	$ 4,352			4,352
Date of Construction or Acquisition	2015
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year	$ 4,352
Unimproved Land [Member] | Grand Forks Grand Forks, ND [Member]
Initial Cost to Company [Abstract]
Land				4,278
Gross amount at which carried at close of period [Abstract]
Land				4,278
Total	$ 4,278			4,278
Date of Construction or Acquisition	2012
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year	$ 4,278
Unimproved Land [Member] | Isanti Unimproved - Isanti, MN [Member]
Initial Cost to Company [Abstract]
Land				58
Gross amount at which carried at close of period [Abstract]
Land				58
Total	$ 58			58
Date of Construction or Acquisition	2014
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year	$ 58
Unimproved Land [Member] | Minot 1525 24th Ave SW - Minot, ND [Member]
Initial Cost to Company [Abstract]
Land				1,262
Gross amount at which carried at close of period [Abstract]
Land				1,262
Total	$ 1,262			1,262
Date of Construction or Acquisition	2015
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year	$ 1,262
Unimproved Land [Member] | Rapid City Unimproved- Rapid City, SD [Member]
Initial Cost to Company [Abstract]
Land				1,376
Gross amount at which carried at close of period [Abstract]
Land				1,376
Total	$ 1,376			1,376
Date of Construction or Acquisition	2014
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year	$ 1,376
Unimproved Land [Member] | Urbandale - Urbandale, IA [Member]
Initial Cost to Company [Abstract]
Land				5
Costs capitalized subsequent to acquisition				109
Gross amount at which carried at close of period [Abstract]
Land				114
Total	$ 114			114
Date of Construction or Acquisition	2009
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year	$ 114
Unimproved Land [Member] | Weston - Weston, WI [Member]
Initial Cost to Company [Abstract]
Land				370
Gross amount at which carried at close of period [Abstract]
Land				370
Total	$ 370			370
Date of Construction or Acquisition	2006
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year	$ 370
Multi-Family Residential [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				623,429
Initial Cost to Company [Abstract]
Land				79,801
Buildings & Improvements				1,013,203
Costs capitalized subsequent to acquisition				150,905
Gross amount at which carried at close of period [Abstract]
Land				98,012
Buildings & Improvements				1,145,897
Total	1,243,909			1,243,909
Accumulated Depreciation	(209,156)			(209,156)
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year	1,243,909
Deductions during year [Abstract]
Balance at close of year	209,156
Multi-Family Residential [Member] | 71 France - Edina, MN [Member]
Initial Cost to Company [Abstract]
Land				3,220
Buildings & Improvements				38,092
Costs capitalized subsequent to acquisition				27
Gross amount at which carried at close of period [Abstract]
Land				3,220
Buildings & Improvements				38,119
Total	41,339			41,339
Accumulated Depreciation	$ (611)			(611)
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	$ 41,339
Deductions during year [Abstract]
Balance at close of year	611
Multi-Family Residential [Member] | 11th Street 3 Plex - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				81
Initial Cost to Company [Abstract]
Land				11
Buildings & Improvements				53
Costs capitalized subsequent to acquisition				20
Gross amount at which carried at close of period [Abstract]
Land				20
Buildings & Improvements				64
Total	84			84
Accumulated Depreciation	$ (15)			(15)
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	$ 84
Deductions during year [Abstract]
Balance at close of year	15
Multi-Family Residential [Member] | 4th Street 4 Plex - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				94
Initial Cost to Company [Abstract]
Land				15
Buildings & Improvements				74
Costs capitalized subsequent to acquisition				37
Gross amount at which carried at close of period [Abstract]
Land				26
Buildings & Improvements				100
Total	126			126
Accumulated Depreciation	$ (23)			(23)
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	$ 126
Deductions during year [Abstract]
Balance at close of year	23
Multi-Family Residential [Member] | Alps Park - Rapid City, SD [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				3,833
Initial Cost to Company [Abstract]
Land				287
Buildings & Improvements				5,551
Costs capitalized subsequent to acquisition				243
Gross amount at which carried at close of period [Abstract]
Land				308
Buildings & Improvements				5,773
Total	6,081			6,081
Accumulated Depreciation	$ (466)			(466)
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	$ 6,081
Deductions during year [Abstract]
Balance at close of year	466
Multi-Family Residential [Member] | Apartments on Main - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				618
Initial Cost to Company [Abstract]
Land				158
Buildings & Improvements				1,123
Costs capitalized subsequent to acquisition				59
Gross amount at which carried at close of period [Abstract]
Land				195
Buildings & Improvements				1,145
Total	1,340			1,340
Accumulated Depreciation	$ (275)			(275)
Date of Construction or Acquisition	1987
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year	$ 1,340
Deductions during year [Abstract]
Balance at close of year	$ 275
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				3,753
Initial Cost to Company [Abstract]
Land				350
Buildings & Improvements				6,625
Costs capitalized subsequent to acquisition				2,119
Gross amount at which carried at close of period [Abstract]
Land				985
Buildings & Improvements				8,109
Total	$ 9,094			9,094
Accumulated Depreciation	$ (2,432)			(2,432)
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	$ 9,094
Deductions during year [Abstract]
Balance at close of year	2,432
Multi-Family Residential [Member] | Arcata - Golden Valley, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				23,321
Initial Cost to Company [Abstract]
Land				2,088
Buildings & Improvements				30,613
Costs capitalized subsequent to acquisition				58
Gross amount at which carried at close of period [Abstract]
Land				2,089
Buildings & Improvements				30,670
Total	32,759			32,759
Accumulated Depreciation	$ (1,438)			(1,438)
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	$ 32,759
Deductions during year [Abstract]
Balance at close of year	1,438
Multi-Family Residential [Member] | Ashland - Grand Forks, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				5,414
Initial Cost to Company [Abstract]
Land				741
Buildings & Improvements				7,569
Costs capitalized subsequent to acquisition				202
Gross amount at which carried at close of period [Abstract]
Land				783
Buildings & Improvements				7,729
Total	8,512			8,512
Accumulated Depreciation	$ (902)			(902)
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	$ 8,512
Deductions during year [Abstract]
Balance at close of year	902
Multi-Family Residential [Member] | Avalon Cove - Rochester, MN
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				25,900
Initial Cost to Company [Abstract]
Land				1,616
Buildings & Improvements				34,074
Costs capitalized subsequent to acquisition				9
Gross amount at which carried at close of period [Abstract]
Land				1,616
Buildings & Improvements				34,083
Total	35,699			35,699
Accumulated Depreciation	$ (109)			(109)
Date of Construction or Acquisition	2016
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	$ 35,699
Deductions during year [Abstract]
Balance at close of year	109
Multi-Family Residential [Member] | Boulder Court - Eagan, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				2,468
Initial Cost to Company [Abstract]
Land				1,067
Buildings & Improvements				5,498
Costs capitalized subsequent to acquisition				3,008
Gross amount at which carried at close of period [Abstract]
Land				1,391
Buildings & Improvements				8,182
Total	9,573			9,573
Accumulated Depreciation	$ (2,713)			(2,713)
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	$ 9,573
Deductions during year [Abstract]
Balance at close of year	2,713
Multi-Family Residential [Member] | Brookfield Village - Topeka, KS [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				5,124
Initial Cost to Company [Abstract]
Land				509
Buildings & Improvements				6,698
Costs capitalized subsequent to acquisition				1,618
Gross amount at which carried at close of period [Abstract]
Land				773
Buildings & Improvements				8,052
Total	8,825			8,825
Accumulated Depreciation	$ (2,531)			(2,531)
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	$ 8,825
Deductions during year [Abstract]
Balance at close of year	2,531
Multi-Family Residential [Member] | Brooklyn Heights - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				636
Initial Cost to Company [Abstract]
Land				145
Buildings & Improvements				1,450
Costs capitalized subsequent to acquisition				979
Gross amount at which carried at close of period [Abstract]
Land				235
Buildings & Improvements				2,339
Total	2,574			2,574
Accumulated Depreciation	$ (1,012)			(1,012)
Date of Construction or Acquisition	1997
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year	$ 2,574
Deductions during year [Abstract]
Balance at close of year	$ 1,012
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] | Canyon Lake - Rapid City, SD [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				2,791
Initial Cost to Company [Abstract]
Land				305
Buildings & Improvements				3,958
Costs capitalized subsequent to acquisition				1,748
Gross amount at which carried at close of period [Abstract]
Land				397
Buildings & Improvements				5,614
Total	$ 6,011			6,011
Accumulated Depreciation	$ (1,943)			(1,943)
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	$ 6,011
Deductions during year [Abstract]
Balance at close of year	1,943
Multi-Family Residential [Member] | Cardinal Point - Grand Forks, ND
Initial Cost to Company [Abstract]
Land				1,600
Buildings & Improvements				47,334
Costs capitalized subsequent to acquisition				838
Gross amount at which carried at close of period [Abstract]
Land				1,600
Buildings & Improvements				48,172
Total	49,772			49,772
Accumulated Depreciation	$ (587)			(587)
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	$ 49,772
Deductions during year [Abstract]
Balance at close of year	587
Multi-Family Residential [Member] | Cascade Shores - Rochester, MN
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				11,400
Initial Cost to Company [Abstract]
Land				1,585
Buildings & Improvements				16,710
Gross amount at which carried at close of period [Abstract]
Land				1,585
Buildings & Improvements				16,710
Total	18,295			18,295
Accumulated Depreciation	$ (149)			(149)
Date of Construction or Acquisition	2016
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	$ 18,295
Deductions during year [Abstract]
Balance at close of year	149
Multi-Family Residential [Member] | Castlerock - Billings, MT [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				6,465
Initial Cost to Company [Abstract]
Land				736
Buildings & Improvements				4,864
Costs capitalized subsequent to acquisition				2,281
Gross amount at which carried at close of period [Abstract]
Land				1,011
Buildings & Improvements				6,870
Total	7,881			7,881
Accumulated Depreciation	$ (2,963)			(2,963)
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	$ 7,881
Deductions during year [Abstract]
Balance at close of year	2,963
Multi-Family Residential [Member] | Chateau I & II - Minot, ND
Initial Cost to Company [Abstract]
Land				301
Buildings & Improvements				20,065
Costs capitalized subsequent to acquisition				760
Gross amount at which carried at close of period [Abstract]
Land				317
Buildings & Improvements				20,809
Total	21,126			21,126
Accumulated Depreciation	$ (1,364)			(1,364)
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	$ 21,126
Deductions during year [Abstract]
Balance at close of year	1,364
Multi-Family Residential [Member] | Cimarron Hills - Omaha, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				4,648
Initial Cost to Company [Abstract]
Land				706
Buildings & Improvements				9,588
Costs capitalized subsequent to acquisition				4,466
Gross amount at which carried at close of period [Abstract]
Land				1,376
Buildings & Improvements				13,384
Total	14,760			14,760
Accumulated Depreciation	$ (5,139)			(5,139)
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	$ 14,760
Deductions during year [Abstract]
Balance at close of year	5,139
Multi-Family Residential [Member] | Colonial Villa - Burnsville, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				4,937
Initial Cost to Company [Abstract]
Land				2,401
Buildings & Improvements				11,515
Costs capitalized subsequent to acquisition				8,191
Gross amount at which carried at close of period [Abstract]
Land				2,878
Buildings & Improvements				19,229
Total	22,107			22,107
Accumulated Depreciation	$ (5,958)			(5,958)
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	$ 22,107
Deductions during year [Abstract]
Balance at close of year	5,958
Multi-Family Residential [Member] | Colony - Lincoln, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				13,032
Initial Cost to Company [Abstract]
Land				1,515
Buildings & Improvements				15,730
Costs capitalized subsequent to acquisition				941
Gross amount at which carried at close of period [Abstract]
Land				1,609
Buildings & Improvements				16,577
Total	18,186			18,186
Accumulated Depreciation	$ (1,826)			(1,826)
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	$ 18,186
Deductions during year [Abstract]
Balance at close of year	1,826
Multi-Family Residential [Member] | Colton Heights - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				358
Initial Cost to Company [Abstract]
Land				80
Buildings & Improvements				672
Costs capitalized subsequent to acquisition				441
Gross amount at which carried at close of period [Abstract]
Land				123
Buildings & Improvements				1,070
Total	1,193			1,193
Accumulated Depreciation	$ (808)			(808)
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	$ 1,193
Deductions during year [Abstract]
Balance at close of year	808
Multi-Family Residential [Member] | Commons at Southgate - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				21,760
Initial Cost to Company [Abstract]
Land				3,691
Buildings & Improvements				32,572
Costs capitalized subsequent to acquisition				360
Gross amount at which carried at close of period [Abstract]
Land				3,796
Buildings & Improvements				32,827
Total	36,623			36,623
Accumulated Depreciation	$ (1,914)			(1,914)
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	$ 36,623
Deductions during year [Abstract]
Balance at close of year	1,914
Multi-Family Residential [Member] | Cottage West Twin Homes - Sioux Falls, SD [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				3,523
Initial Cost to Company [Abstract]
Land				968
Buildings & Improvements				3,762
Costs capitalized subsequent to acquisition				495
Gross amount at which carried at close of period [Abstract]
Land				1,041
Buildings & Improvements				4,184
Total	5,225			5,225
Accumulated Depreciation	$ (496)			(496)
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	$ 5,225
Deductions during year [Abstract]
Balance at close of year	496
Multi-Family Residential [Member] | Cottonwood - Bismarck, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				15,358
Initial Cost to Company [Abstract]
Land				1,056
Buildings & Improvements				17,372
Costs capitalized subsequent to acquisition				3,851
Gross amount at which carried at close of period [Abstract]
Land				1,460
Buildings & Improvements				20,819
Total	22,279			22,279
Accumulated Depreciation	$ (7,469)			(7,469)
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	$ 22,279
Deductions during year [Abstract]
Balance at close of year	7,469
Multi-Family Residential [Member] | Country Meadows - Billings, MT [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				6,436
Initial Cost to Company [Abstract]
Land				491
Buildings & Improvements				7,809
Costs capitalized subsequent to acquisition				1,653
Gross amount at which carried at close of period [Abstract]
Land				543
Buildings & Improvements				9,410
Total	9,953			9,953
Accumulated Depreciation	$ (4,086)			(4,086)
Date of Construction or Acquisition	1995
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year	$ 9,953
Deductions during year [Abstract]
Balance at close of year	$ 4,086
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				3,757
Initial Cost to Company [Abstract]
Land				235
Buildings & Improvements				4,290
Costs capitalized subsequent to acquisition				1,853
Gross amount at which carried at close of period [Abstract]
Land				536
Buildings & Improvements				5,842
Total	$ 6,378			6,378
Accumulated Depreciation	$ (3,081)			(3,081)
Date of Construction or Acquisition	1994
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year	$ 6,378
Deductions during year [Abstract]
Balance at close of year	$ 3,081
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				2,509
Initial Cost to Company [Abstract]
Land				261
Buildings & Improvements				3,289
Costs capitalized subsequent to acquisition				275
Gross amount at which carried at close of period [Abstract]
Land				269
Buildings & Improvements				3,556
Total	$ 3,825			3,825
Accumulated Depreciation	$ (575)			(575)
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	$ 3,825
Deductions during year [Abstract]
Balance at close of year	575
Multi-Family Residential [Member] | Crown Colony - Topeka, KS [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				7,936
Initial Cost to Company [Abstract]
Land				620
Buildings & Improvements				9,956
Costs capitalized subsequent to acquisition				2,630
Gross amount at which carried at close of period [Abstract]
Land				954
Buildings & Improvements				12,252
Total	13,206			13,206
Accumulated Depreciation	$ (4,868)			(4,868)
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	$ 13,206
Deductions during year [Abstract]
Balance at close of year	4,868
Multi-Family Residential [Member] | Crystal Bay - Rochester, MN
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				8,000
Initial Cost to Company [Abstract]
Land				433
Buildings & Improvements				11,425
Gross amount at which carried at close of period [Abstract]
Land				433
Buildings & Improvements				11,425
Total	11,858			11,858
Accumulated Depreciation	$ (54)			(54)
Date of Construction or Acquisition	2016
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	$ 11,858
Deductions during year [Abstract]
Balance at close of year	54
Multi-Family Residential [Member] | Cypress Court - St. Cloud, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				12,922
Initial Cost to Company [Abstract]
Land				1,583
Buildings & Improvements				18,879
Costs capitalized subsequent to acquisition				162
Gross amount at which carried at close of period [Abstract]
Land				1,591
Buildings & Improvements				19,033
Total	20,624			20,624
Accumulated Depreciation	$ (1,280)			(1,280)
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	$ 20,624
Deductions during year [Abstract]
Balance at close of year	1,280
Multi-Family Residential [Member] | Dakota Commons - Williston, ND [Member]
Initial Cost to Company [Abstract]
Land				823
Buildings & Improvements				9,597
Costs capitalized subsequent to acquisition				97
Gross amount at which carried at close of period [Abstract]
Land				871
Buildings & Improvements				9,646
Total	10,517			10,517
Accumulated Depreciation	$ (571)			(571)
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	$ 10,517
Deductions during year [Abstract]
Balance at close of year	571
Multi-Family Residential [Member] | 163 unit - Deer Ridge - Jamestown, ND
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				11,673
Initial Cost to Company [Abstract]
Land				711
Buildings & Improvements				24,117
Costs capitalized subsequent to acquisition				69
Gross amount at which carried at close of period [Abstract]
Land				711
Buildings & Improvements				24,186
Total	24,897			24,897
Accumulated Depreciation	$ (440)			(440)
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	$ 24,897
Deductions during year [Abstract]
Balance at close of year	440
Multi-Family Residential [Member] | Evergreen - Isanti, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				1,951
Initial Cost to Company [Abstract]
Land				380
Buildings & Improvements				2,740
Costs capitalized subsequent to acquisition				142
Gross amount at which carried at close of period [Abstract]
Land				385
Buildings & Improvements				2,877
Total	3,262			3,262
Accumulated Depreciation	$ (552)			(552)
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	$ 3,262
Deductions during year [Abstract]
Balance at close of year	552
Multi-Family Residential [Member] | Evergreen II - Isanti, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				2,020
Initial Cost to Company [Abstract]
Land				691
Buildings & Improvements				2,784
Costs capitalized subsequent to acquisition				92
Gross amount at which carried at close of period [Abstract]
Land				698
Buildings & Improvements				2,869
Total	3,567			3,567
Accumulated Depreciation	$ (361)			(361)
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	$ 3,567
Deductions during year [Abstract]
Balance at close of year	361
Multi-Family Residential [Member] | Fairmont - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				319
Initial Cost to Company [Abstract]
Land				28
Buildings & Improvements				337
Costs capitalized subsequent to acquisition				116
Gross amount at which carried at close of period [Abstract]
Land				56
Buildings & Improvements				425
Total	481			481
Accumulated Depreciation	$ (93)			(93)
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	$ 481
Deductions during year [Abstract]
Balance at close of year	93
Multi-Family Residential [Member] | First Avenue - Minot ND [Member]
Initial Cost to Company [Abstract]
Buildings & Improvements				3,046
Costs capitalized subsequent to acquisition				21
Gross amount at which carried at close of period [Abstract]
Buildings & Improvements				3,067
Total	3,067			3,067
Accumulated Depreciation	$ (234)			(234)
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	$ 3,067
Deductions during year [Abstract]
Balance at close of year	234
Multi-Family Residential [Member] | Forest Park - Grand Forks, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				7,422
Initial Cost to Company [Abstract]
Land				810
Buildings & Improvements				5,579
Costs capitalized subsequent to acquisition				7,746
Gross amount at which carried at close of period [Abstract]
Land				1,439
Buildings & Improvements				12,696
Total	14,135			14,135
Accumulated Depreciation	$ (5,776)			(5,776)
Date of Construction or Acquisition	1993
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year	$ 14,135
Deductions during year [Abstract]
Balance at close of year	$ 5,776
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] | French Creek - Rochester, MN
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				3,100
Initial Cost to Company [Abstract]
Land				201
Buildings & Improvements				4,735
Gross amount at which carried at close of period [Abstract]
Land				201
Buildings & Improvements				4,735
Total	$ 4,936			4,936
Accumulated Depreciation	$ (28)			(28)
Date of Construction or Acquisition	2016
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	$ 4,936
Deductions during year [Abstract]
Balance at close of year	28
Multi-Family Residential [Member] | Gables Townhomes - Sioux Falls, SD [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				1,426
Initial Cost to Company [Abstract]
Land				349
Buildings & Improvements				1,921
Costs capitalized subsequent to acquisition				193
Gross amount at which carried at close of period [Abstract]
Land				377
Buildings & Improvements				2,086
Total	2,463			2,463
Accumulated Depreciation	$ (246)			(246)
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	$ 2,463
Deductions during year [Abstract]
Balance at close of year	246
Multi-Family Residential [Member] | Gardens - Grand Forks, ND [Member]
Initial Cost to Company [Abstract]
Land				518
Buildings & Improvements				8,702
Costs capitalized subsequent to acquisition				71
Gross amount at which carried at close of period [Abstract]
Land				519
Buildings & Improvements				8,772
Total	9,291			9,291
Accumulated Depreciation	$ (155)			(155)
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	$ 9,291
Deductions during year [Abstract]
Balance at close of year	155
Multi-Family Residential [Member] | Grand Gateway - St. Cloud, MN [Member]
Initial Cost to Company [Abstract]
Land				814
Buildings & Improvements				7,086
Costs capitalized subsequent to acquisition				1,119
Gross amount at which carried at close of period [Abstract]
Land				935
Buildings & Improvements				8,084
Total	9,019			9,019
Accumulated Depreciation	$ (1,027)			(1,027)
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	$ 9,019
Deductions during year [Abstract]
Balance at close of year	1,027
Multi-Family Residential [Member] | GrandeVille at Cascade Lake - Rochester, MN
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				36,000
Initial Cost to Company [Abstract]
Land				5,003
Buildings & Improvements				50,363
Costs capitalized subsequent to acquisition				220
Gross amount at which carried at close of period [Abstract]
Land				5,027
Buildings & Improvements				50,559
Total	55,586			55,586
Accumulated Depreciation	$ (673)			(673)
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	$ 55,586
Deductions during year [Abstract]
Balance at close of year	673
Multi-Family Residential [Member] | Greenfield - Omaha, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				3,503
Initial Cost to Company [Abstract]
Land				578
Buildings & Improvements				4,122
Costs capitalized subsequent to acquisition				935
Gross amount at which carried at close of period [Abstract]
Land				824
Buildings & Improvements				4,811
Total	5,635			5,635
Accumulated Depreciation	$ (1,092)			(1,092)
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	$ 5,635
Deductions during year [Abstract]
Balance at close of year	1,092
Multi-Family Residential [Member] | Heritage Manor - Rochester, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				3,731
Initial Cost to Company [Abstract]
Land				403
Buildings & Improvements				6,968
Costs capitalized subsequent to acquisition				2,915
Gross amount at which carried at close of period [Abstract]
Land				582
Buildings & Improvements				9,704
Total	10,286			10,286
Accumulated Depreciation	$ (4,039)			(4,039)
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	$ 10,286
Deductions during year [Abstract]
Balance at close of year	4,039
Multi-Family Residential [Member] | Homestead Garden - Rapid City, SD [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				9,585
Initial Cost to Company [Abstract]
Land				655
Buildings & Improvements				14,139
Costs capitalized subsequent to acquisition				282
Gross amount at which carried at close of period [Abstract]
Land				694
Buildings & Improvements				14,382
Total	15,076			15,076
Accumulated Depreciation	$ (737)			(737)
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	$ 15,076
Deductions during year [Abstract]
Balance at close of year	737
Multi-Family Residential [Member] | Indian Hills - Sioux City, IA [Member]
Initial Cost to Company [Abstract]
Land				294
Buildings & Improvements				2,921
Costs capitalized subsequent to acquisition				3,933
Gross amount at which carried at close of period [Abstract]
Land				410
Buildings & Improvements				6,738
Total	7,148			7,148
Accumulated Depreciation	$ (1,574)			(1,574)
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	$ 7,148
Deductions during year [Abstract]
Balance at close of year	1,574
Multi-Family Residential [Member] | Kirkwood Manor - Bismarck, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				3,204
Initial Cost to Company [Abstract]
Land				449
Buildings & Improvements				2,725
Costs capitalized subsequent to acquisition				1,767
Gross amount at which carried at close of period [Abstract]
Land				577
Buildings & Improvements				4,364
Total	4,941			4,941
Accumulated Depreciation	$ (1,907)			(1,907)
Date of Construction or Acquisition	1997
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year	$ 4,941
Deductions during year [Abstract]
Balance at close of year	$ 1,907
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				12,867
Initial Cost to Company [Abstract]
Land				1,215
Buildings & Improvements				15,837
Costs capitalized subsequent to acquisition				620
Gross amount at which carried at close of period [Abstract]
Land				1,280
Buildings & Improvements				16,392
Total	$ 17,672			17,672
Accumulated Depreciation	$ (1,785)			(1,785)
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	$ 17,672
Deductions during year [Abstract]
Balance at close of year	1,785
Multi-Family Residential [Member] | Landing at Southgate - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				10,240
Initial Cost to Company [Abstract]
Land				2,254
Buildings & Improvements				14,958
Costs capitalized subsequent to acquisition				187
Gross amount at which carried at close of period [Abstract]
Land				2,319
Buildings & Improvements				15,080
Total	17,399			17,399
Accumulated Depreciation	$ (916)			(916)
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	$ 17,399
Deductions during year [Abstract]
Balance at close of year	916
Multi-Family Residential [Member] | Landmark - Grand Forks, ND [Member]
Initial Cost to Company [Abstract]
Land				184
Buildings & Improvements				1,514
Costs capitalized subsequent to acquisition				1,154
Gross amount at which carried at close of period [Abstract]
Land				353
Buildings & Improvements				2,499
Total	2,852			2,852
Accumulated Depreciation	$ (1,150)			(1,150)
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	$ 2,852
Deductions during year [Abstract]
Balance at close of year	1,150
Multi-Family Residential [Member] | Legacy - Grand Forks, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				15,151
Initial Cost to Company [Abstract]
Land				1,362
Buildings & Improvements				21,727
Costs capitalized subsequent to acquisition				7,505
Gross amount at which carried at close of period [Abstract]
Land				2,227
Buildings & Improvements				28,367
Total	30,594			30,594
Accumulated Depreciation	(11,020)			(11,020)
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year	30,594
Deductions during year [Abstract]
Balance at close of year	$ 11,020
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]
Initial Cost to Company [Abstract]
Land				1,207
Buildings & Improvements				13,742
Costs capitalized subsequent to acquisition				225
Gross amount at which carried at close of period [Abstract]
Land				1,229
Buildings & Improvements				13,945
Total	$ 15,174			15,174
Accumulated Depreciation	$ (412)			(412)
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	$ 15,174
Deductions during year [Abstract]
Balance at close of year	412
Multi-Family Residential [Member] | Mariposa - Topeka, KS [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				2,872
Initial Cost to Company [Abstract]
Land				399
Buildings & Improvements				5,110
Costs capitalized subsequent to acquisition				565
Gross amount at which carried at close of period [Abstract]
Land				428
Buildings & Improvements				5,646
Total	6,074			6,074
Accumulated Depreciation	$ (1,627)			(1,627)
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	$ 6,074
Deductions during year [Abstract]
Balance at close of year	1,627
Multi-Family Residential [Member] | Meadows - Jamestown, ND [Member]
Initial Cost to Company [Abstract]
Land				590
Buildings & Improvements				4,519
Costs capitalized subsequent to acquisition				1,520
Gross amount at which carried at close of period [Abstract]
Land				678
Buildings & Improvements				5,951
Total	6,629			6,629
Accumulated Depreciation	$ (2,297)			(2,297)
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	$ 6,629
Deductions during year [Abstract]
Balance at close of year	2,297
Multi-Family Residential [Member] | Monticello Village - Monticello, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				2,901
Initial Cost to Company [Abstract]
Land				490
Buildings & Improvements				3,756
Costs capitalized subsequent to acquisition				603
Gross amount at which carried at close of period [Abstract]
Land				625
Buildings & Improvements				4,224
Total	4,849			4,849
Accumulated Depreciation	$ (1,371)			(1,371)
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	$ 4,849
Deductions during year [Abstract]
Balance at close of year	1,371
Multi-Family Residential [Member] | Northern Valley - Rochester, MN [Member]
Initial Cost to Company [Abstract]
Land				110
Buildings & Improvements				610
Costs capitalized subsequent to acquisition				140
Gross amount at which carried at close of period [Abstract]
Land				122
Buildings & Improvements				738
Total	860			860
Accumulated Depreciation	$ (126)			(126)
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	$ 860
Deductions during year [Abstract]
Balance at close of year	126
Multi-Family Residential [Member] | North Pointe - Bismarck, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				3,330
Initial Cost to Company [Abstract]
Land				303
Buildings & Improvements				3,957
Costs capitalized subsequent to acquisition				808
Gross amount at which carried at close of period [Abstract]
Land				357
Buildings & Improvements				4,711
Total	5,068			5,068
Accumulated Depreciation	(1,579)			(1,579)
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year	5,068
Deductions during year [Abstract]
Balance at close of year	$ 1,579
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				6,146
Initial Cost to Company [Abstract]
Land				884
Buildings & Improvements				7,516
Costs capitalized subsequent to acquisition				96
Gross amount at which carried at close of period [Abstract]
Land				946
Buildings & Improvements				7,550
Total	$ 8,496			8,496
Accumulated Depreciation	$ (334)			(334)
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	$ 8,496
Deductions during year [Abstract]
Balance at close of year	334
Multi-Family Residential [Member] | Oakmont Estates - Sioux Falls, SD [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				2,361
Initial Cost to Company [Abstract]
Land				422
Buildings & Improvements				4,838
Costs capitalized subsequent to acquisition				721
Gross amount at which carried at close of period [Abstract]
Land				639
Buildings & Improvements				5,342
Total	5,981			5,981
Accumulated Depreciation	$ (1,910)			(1,910)
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	$ 5,981
Deductions during year [Abstract]
Balance at close of year	1,910
Multi-Family Residential [Member] | Oakwood Estates - Sioux Falls, SD [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				3,847
Initial Cost to Company [Abstract]
Land				543
Buildings & Improvements				2,784
Costs capitalized subsequent to acquisition				4,470
Gross amount at which carried at close of period [Abstract]
Land				837
Buildings & Improvements				6,960
Total	7,797			7,797
Accumulated Depreciation	$ (3,422)			(3,422)
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	$ 7,797
Deductions during year [Abstract]
Balance at close of year	3,422
Multi-Family Residential [Member] | Olympic Village - Billings, MT [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				10,372
Initial Cost to Company [Abstract]
Land				1,164
Buildings & Improvements				10,441
Costs capitalized subsequent to acquisition				3,312
Gross amount at which carried at close of period [Abstract]
Land				1,799
Buildings & Improvements				13,118
Total	14,917			14,917
Accumulated Depreciation	$ (5,266)			(5,266)
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	$ 14,917
Deductions during year [Abstract]
Balance at close of year	5,266
Multi-Family Residential [Member] | Olympik Village - Rochester, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				4,259
Initial Cost to Company [Abstract]
Land				1,034
Buildings & Improvements				6,109
Costs capitalized subsequent to acquisition				2,315
Gross amount at which carried at close of period [Abstract]
Land				1,187
Buildings & Improvements				8,271
Total	9,458			9,458
Accumulated Depreciation	$ (2,346)			(2,346)
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	$ 9,458
Deductions during year [Abstract]
Balance at close of year	2,346
Multi-Family Residential [Member] | Oxbow Park - Sioux Falls, SD [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				3,757
Initial Cost to Company [Abstract]
Land				404
Buildings & Improvements				3,152
Costs capitalized subsequent to acquisition				3,178
Gross amount at which carried at close of period [Abstract]
Land				957
Buildings & Improvements				5,777
Total	6,734			6,734
Accumulated Depreciation	$ (2,987)			(2,987)
Date of Construction or Acquisition	1994
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year	$ 6,734
Deductions during year [Abstract]
Balance at close of year	$ 2,987
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				8,342
Initial Cost to Company [Abstract]
Land				1,143
Buildings & Improvements				9,099
Costs capitalized subsequent to acquisition				7,594
Gross amount at which carried at close of period [Abstract]
Land				1,766
Buildings & Improvements				16,070
Total	$ 17,836			17,836
Accumulated Depreciation	$ (6,454)			(6,454)
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	$ 17,836
Deductions during year [Abstract]
Balance at close of year	6,454
Multi-Family Residential [Member] | Pebble Springs - Bismarck, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				738
Initial Cost to Company [Abstract]
Land				7
Buildings & Improvements				748
Costs capitalized subsequent to acquisition				182
Gross amount at which carried at close of period [Abstract]
Land				55
Buildings & Improvements				882
Total	937			937
Accumulated Depreciation	$ (373)			(373)
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	$ 937
Deductions during year [Abstract]
Balance at close of year	373
Multi-Family Residential [Member] | Pinehurst - Billings, MT [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				164
Initial Cost to Company [Abstract]
Land				72
Buildings & Improvements				687
Costs capitalized subsequent to acquisition				360
Gross amount at which carried at close of period [Abstract]
Land				112
Buildings & Improvements				1,007
Total	1,119			1,119
Accumulated Depreciation	$ (332)			(332)
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	$ 1,119
Deductions during year [Abstract]
Balance at close of year	332
Multi-Family Residential [Member] | Pines - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				102
Initial Cost to Company [Abstract]
Land				35
Buildings & Improvements				215
Costs capitalized subsequent to acquisition				187
Gross amount at which carried at close of period [Abstract]
Land				49
Buildings & Improvements				388
Total	437			437
Accumulated Depreciation	$ (148)			(148)
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	$ 437
Deductions during year [Abstract]
Balance at close of year	148
Multi-Family Residential [Member] | Plaza - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				5,212
Initial Cost to Company [Abstract]
Land				867
Buildings & Improvements				12,784
Costs capitalized subsequent to acquisition				2,617
Gross amount at which carried at close of period [Abstract]
Land				998
Buildings & Improvements				15,270
Total	16,268			16,268
Accumulated Depreciation	$ (2,851)			(2,851)
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	$ 16,268
Deductions during year [Abstract]
Balance at close of year	2,851
Multi-Family Residential [Member] | Pointe West - Rapid City, SD [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				2,566
Initial Cost to Company [Abstract]
Land				240
Buildings & Improvements				3,538
Costs capitalized subsequent to acquisition				1,674
Gross amount at which carried at close of period [Abstract]
Land				388
Buildings & Improvements				5,064
Total	5,452			5,452
Accumulated Depreciation	$ (2,522)			(2,522)
Date of Construction or Acquisition	1994
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year	$ 5,452
Deductions during year [Abstract]
Balance at close of year	$ 2,522
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				3,749
Initial Cost to Company [Abstract]
Land				395
Buildings & Improvements				4,564
Costs capitalized subsequent to acquisition				400
Gross amount at which carried at close of period [Abstract]
Land				410
Buildings & Improvements				4,949
Total	$ 5,359			5,359
Accumulated Depreciation	$ (517)			(517)
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	$ 5,359
Deductions during year [Abstract]
Balance at close of year	517
Multi-Family Residential [Member] | Prairie Winds - Sioux Falls, SD [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				1,381
Initial Cost to Company [Abstract]
Land				144
Buildings & Improvements				1,816
Costs capitalized subsequent to acquisition				575
Gross amount at which carried at close of period [Abstract]
Land				297
Buildings & Improvements				2,238
Total	2,535			2,535
Accumulated Depreciation	$ (1,296)			(1,296)
Date of Construction or Acquisition	1993
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year	$ 2,535
Deductions during year [Abstract]
Balance at close of year	$ 1,296
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				26,755
Initial Cost to Company [Abstract]
Land				2,254
Buildings & Improvements				30,024
Costs capitalized subsequent to acquisition				1,690
Gross amount at which carried at close of period [Abstract]
Land				2,363
Buildings & Improvements				31,605
Total	$ 33,968			33,968
Accumulated Depreciation	$ (5,450)			(5,450)
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	$ 33,968
Deductions during year [Abstract]
Balance at close of year	5,450
Multi-Family Residential [Member] | RED 20 - Minneapolis, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				23,200
Initial Cost to Company [Abstract]
Land				1,900
Buildings & Improvements				26,641
Costs capitalized subsequent to acquisition				65
Gross amount at which carried at close of period [Abstract]
Land				1,900
Buildings & Improvements				26,706
Total	28,606			28,606
Accumulated Depreciation	$ (1,349)			(1,349)
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	$ 28,606
Deductions during year [Abstract]
Balance at close of year	1,349
Multi-Family Residential [Member] | Regency Park Estates - St. Cloud, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				8,368
Initial Cost to Company [Abstract]
Land				702
Buildings & Improvements				10,198
Costs capitalized subsequent to acquisition				1,760
Gross amount at which carried at close of period [Abstract]
Land				873
Buildings & Improvements				11,787
Total	12,660			12,660
Accumulated Depreciation	$ (1,539)			(1,539)
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	$ 12,660
Deductions during year [Abstract]
Balance at close of year	1,539
Multi-Family Residential [Member] | 288 unit - Renaissance Heights - Williston, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				42,221
Initial Cost to Company [Abstract]
Land				3,080
Buildings & Improvements				59,434
Costs capitalized subsequent to acquisition				286
Gross amount at which carried at close of period [Abstract]
Land				3,089
Buildings & Improvements				59,711
Total	62,800			62,800
Accumulated Depreciation	$ (2,956)			(2,956)
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	$ 62,800
Deductions during year [Abstract]
Balance at close of year	2,956
Multi-Family Residential [Member] | Ridge Oaks - Sioux City, IA [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				3,301
Initial Cost to Company [Abstract]
Land				178
Buildings & Improvements				4,073
Costs capitalized subsequent to acquisition				2,532
Gross amount at which carried at close of period [Abstract]
Land				307
Buildings & Improvements				6,476
Total	6,783			6,783
Accumulated Depreciation	$ (2,394)			(2,394)
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	$ 6,783
Deductions during year [Abstract]
Balance at close of year	2,394
Multi-Family Residential [Member] | Rimrock West - Billings, MT [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				3,223
Initial Cost to Company [Abstract]
Land				330
Buildings & Improvements				3,489
Costs capitalized subsequent to acquisition				1,706
Gross amount at which carried at close of period [Abstract]
Land				447
Buildings & Improvements				5,078
Total	5,525			5,525
Accumulated Depreciation	$ (1,902)			(1,902)
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	$ 5,525
Deductions during year [Abstract]
Balance at close of year	1,902
Multi-Family Residential [Member] | River Ridge - Bismarck, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				13,000
Initial Cost to Company [Abstract]
Land				576
Buildings & Improvements				24,695
Costs capitalized subsequent to acquisition				435
Gross amount at which carried at close of period [Abstract]
Land				662
Buildings & Improvements				25,044
Total	25,706			25,706
Accumulated Depreciation	$ (2,167)			(2,167)
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	$ 25,706
Deductions during year [Abstract]
Balance at close of year	2,167
Multi-Family Residential [Member] | Rocky Meadows - Billings, MT [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				4,997
Initial Cost to Company [Abstract]
Land				656
Buildings & Improvements				5,726
Costs capitalized subsequent to acquisition				1,437
Gross amount at which carried at close of period [Abstract]
Land				775
Buildings & Improvements				7,044
Total	7,819			7,819
Accumulated Depreciation	$ (3,316)			(3,316)
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	$ 7,819
Deductions during year [Abstract]
Balance at close of year	3,316
Multi-Family Residential [Member] | Rum River - Isanti, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				3,461
Initial Cost to Company [Abstract]
Land				843
Buildings & Improvements				4,823
Costs capitalized subsequent to acquisition				269
Gross amount at which carried at close of period [Abstract]
Land				864
Buildings & Improvements				5,071
Total	5,935			5,935
Accumulated Depreciation	$ (1,164)			(1,164)
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	$ 5,935
Deductions during year [Abstract]
Balance at close of year	1,164
Multi-Family Residential [Member] | Sherwood - Topeka, KS [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				11,918
Initial Cost to Company [Abstract]
Land				1,142
Buildings & Improvements				14,684
Costs capitalized subsequent to acquisition				3,405
Gross amount at which carried at close of period [Abstract]
Land				1,745
Buildings & Improvements				17,486
Total	19,231			19,231
Accumulated Depreciation	$ (7,099)			(7,099)
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	$ 19,231
Deductions during year [Abstract]
Balance at close of year	7,099
Multi-Family Residential [Member] | Sierra Vista - Sioux Falls, SD [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				1,358
Initial Cost to Company [Abstract]
Land				241
Buildings & Improvements				2,097
Costs capitalized subsequent to acquisition				477
Gross amount at which carried at close of period [Abstract]
Land				276
Buildings & Improvements				2,539
Total	2,815			2,815
Accumulated Depreciation	$ (350)			(350)
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	$ 2,815
Deductions during year [Abstract]
Balance at close of year	350
Multi-Family Residential [Member] | Silver Springs - Rapid City, SD [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				2,194
Initial Cost to Company [Abstract]
Land				215
Buildings & Improvements				3,006
Costs capitalized subsequent to acquisition				351
Gross amount at which carried at close of period [Abstract]
Land				237
Buildings & Improvements				3,335
Total	3,572			3,572
Accumulated Depreciation	$ (161)			(161)
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	$ 3,572
Deductions during year [Abstract]
Balance at close of year	161
Multi-Family Residential [Member] | South Pointe - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				8,428
Initial Cost to Company [Abstract]
Land				550
Buildings & Improvements				9,548
Costs capitalized subsequent to acquisition				3,836
Gross amount at which carried at close of period [Abstract]
Land				1,362
Buildings & Improvements				12,572
Total	13,934			13,934
Accumulated Depreciation	$ (5,881)			(5,881)
Date of Construction or Acquisition	1995
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year	$ 13,934
Deductions during year [Abstract]
Balance at close of year	$ 5,881
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]
Initial Cost to Company [Abstract]
Land				576
Buildings & Improvements				9,893
Costs capitalized subsequent to acquisition				95
Gross amount at which carried at close of period [Abstract]
Land				605
Buildings & Improvements				9,959
Total	$ 10,564			10,564
Accumulated Depreciation	$ (672)			(672)
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	$ 10,564
Deductions during year [Abstract]
Balance at close of year	672
Multi-Family Residential [Member] | Southview - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				1,009
Initial Cost to Company [Abstract]
Land				185
Buildings & Improvements				469
Costs capitalized subsequent to acquisition				435
Gross amount at which carried at close of period [Abstract]
Land				251
Buildings & Improvements				838
Total	1,089			1,089
Accumulated Depreciation	$ (401)			(401)
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	$ 1,089
Deductions during year [Abstract]
Balance at close of year	401
Multi-Family Residential [Member] | Southwind - Grand Forks, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				5,385
Initial Cost to Company [Abstract]
Land				400
Buildings & Improvements				5,034
Costs capitalized subsequent to acquisition				3,290
Gross amount at which carried at close of period [Abstract]
Land				796
Buildings & Improvements				7,928
Total	8,724			8,724
Accumulated Depreciation	$ (3,754)			(3,754)
Date of Construction or Acquisition	1995
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year	$ 8,724
Deductions during year [Abstract]
Balance at close of year	$ 3,754
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				882
Initial Cost to Company [Abstract]
Land				161
Buildings & Improvements				1,898
Costs capitalized subsequent to acquisition				1,847
Gross amount at which carried at close of period [Abstract]
Land				795
Buildings & Improvements				3,111
Total	$ 3,906			3,906
Accumulated Depreciation	$ (1,347)			(1,347)
Date of Construction or Acquisition	1997
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year	$ 3,906
Deductions during year [Abstract]
Balance at close of year	$ 1,347
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				7,875
Initial Cost to Company [Abstract]
Land				336
Buildings & Improvements				12,814
Costs capitalized subsequent to acquisition				2,926
Gross amount at which carried at close of period [Abstract]
Land				662
Buildings & Improvements				15,414
Total	$ 16,076			16,076
Accumulated Depreciation	$ (5,937)			(5,937)
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	$ 16,076
Deductions during year [Abstract]
Balance at close of year	5,937
Multi-Family Residential [Member] | Temple - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				72
Initial Cost to Company [Abstract]
Costs capitalized subsequent to acquisition				234
Gross amount at which carried at close of period [Abstract]
Buildings & Improvements				234
Total	234			234
Accumulated Depreciation	$ (64)			(64)
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	$ 234
Deductions during year [Abstract]
Balance at close of year	64
Multi-Family Residential [Member] | Terrace Heights - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				147
Initial Cost to Company [Abstract]
Land				29
Buildings & Improvements				312
Costs capitalized subsequent to acquisition				148
Gross amount at which carried at close of period [Abstract]
Land				40
Buildings & Improvements				449
Total	489			489
Accumulated Depreciation	$ (184)			(184)
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	$ 489
Deductions during year [Abstract]
Balance at close of year	184
Multi-Family Residential [Member] | Thomasbrook - Lincoln, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				5,793
Initial Cost to Company [Abstract]
Land				600
Buildings & Improvements				10,306
Costs capitalized subsequent to acquisition				3,578
Gross amount at which carried at close of period [Abstract]
Land				1,421
Buildings & Improvements				13,063
Total	14,484			14,484
Accumulated Depreciation	$ (4,967)			(4,967)
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	$ 14,484
Deductions during year [Abstract]
Balance at close of year	4,967
Multi-Family Residential [Member] | Valley Park - Grand Forks, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				3,755
Initial Cost to Company [Abstract]
Land				294
Buildings & Improvements				4,137
Costs capitalized subsequent to acquisition				3,667
Gross amount at which carried at close of period [Abstract]
Land				1,177
Buildings & Improvements				6,921
Total	8,098			8,098
Accumulated Depreciation	$ (2,827)			(2,827)
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	$ 8,098
Deductions during year [Abstract]
Balance at close of year	2,827
Multi-Family Residential [Member] | Villa West - Topeka, KS [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				11,923
Initial Cost to Company [Abstract]
Land				1,590
Buildings & Improvements				15,760
Costs capitalized subsequent to acquisition				1,152
Gross amount at which carried at close of period [Abstract]
Land				1,942
Buildings & Improvements				16,560
Total	18,502			18,502
Accumulated Depreciation	$ (1,839)			(1,839)
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	$ 18,502
Deductions during year [Abstract]
Balance at close of year	1,839
Multi-Family Residential [Member] | Village Green - Rochester, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				945
Initial Cost to Company [Abstract]
Land				234
Buildings & Improvements				2,296
Costs capitalized subsequent to acquisition				1,009
Gross amount at which carried at close of period [Abstract]
Land				359
Buildings & Improvements				3,180
Total	3,539			3,539
Accumulated Depreciation	$ (1,011)			(1,011)
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	$ 3,539
Deductions during year [Abstract]
Balance at close of year	1,011
Multi-Family Residential [Member] | West Stonehill - Waite Park, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				8,267
Initial Cost to Company [Abstract]
Land				939
Buildings & Improvements				10,167
Costs capitalized subsequent to acquisition				6,436
Gross amount at which carried at close of period [Abstract]
Land				1,673
Buildings & Improvements				15,869
Total	17,542			17,542
Accumulated Depreciation	$ (7,323)			(7,323)
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	$ 17,542
Deductions during year [Abstract]
Balance at close of year	7,323
Multi-Family Residential [Member] | Westridge - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				1,543
Initial Cost to Company [Abstract]
Land				68
Buildings & Improvements				1,887
Costs capitalized subsequent to acquisition				309
Gross amount at which carried at close of period [Abstract]
Land				79
Buildings & Improvements				2,185
Total	2,264			2,264
Accumulated Depreciation	$ (454)			(454)
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	$ 2,264
Deductions during year [Abstract]
Balance at close of year	454
Multi-Family Residential [Member] | Westwood Park - Bismarck, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				1,916
Initial Cost to Company [Abstract]
Land				116
Buildings & Improvements				1,909
Costs capitalized subsequent to acquisition				1,975
Gross amount at which carried at close of period [Abstract]
Land				284
Buildings & Improvements				3,716
Total	4,000			4,000
Accumulated Depreciation	$ (1,546)			(1,546)
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	$ 4,000
Deductions during year [Abstract]
Balance at close of year	1,546
Multi-Family Residential [Member] | Whispering Ridge - Omaha, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				21,653
Initial Cost to Company [Abstract]
Land				2,139
Buildings & Improvements				25,424
Costs capitalized subsequent to acquisition				1,025
Gross amount at which carried at close of period [Abstract]
Land				2,316
Buildings & Improvements				26,272
Total	28,588			28,588
Accumulated Depreciation	$ (2,349)			(2,349)
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	$ 28,588
Deductions during year [Abstract]
Balance at close of year	2,349
Multi-Family Residential [Member] | Williston Garden - Williston, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				10,070
Initial Cost to Company [Abstract]
Land				1,400
Buildings & Improvements				17,696
Costs capitalized subsequent to acquisition				215
Gross amount at which carried at close of period [Abstract]
Land				1,431
Buildings & Improvements				17,880
Total	19,311			19,311
Accumulated Depreciation	$ (2,853)			(2,853)
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	$ 19,311
Deductions during year [Abstract]
Balance at close of year	2,853
Multi-Family Residential [Member] | Winchester - Rochester, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				2,313
Initial Cost to Company [Abstract]
Land				748
Buildings & Improvements				5,622
Costs capitalized subsequent to acquisition				1,877
Gross amount at which carried at close of period [Abstract]
Land				1,016
Buildings & Improvements				7,231
Total	8,247			8,247
Accumulated Depreciation	$ (2,457)			(2,457)
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	$ 8,247
Deductions during year [Abstract]
Balance at close of year	2,457
Multi-Family Residential [Member] | Woodridge - Rochester, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				6,092
Initial Cost to Company [Abstract]
Land				370
Buildings & Improvements				6,028
Costs capitalized subsequent to acquisition				2,388
Gross amount at which carried at close of period [Abstract]
Land				741
Buildings & Improvements				8,045
Total	8,786			8,786
Accumulated Depreciation	$ (3,810)			(3,810)
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	$ 8,786
Deductions during year [Abstract]
Balance at close of year	3,810
Multi-Family Residential [Member] | Wholly Owned Properties [Member]
Reconciliations of total real estate carrying value [Abstract]
Additions	282,457	183,114	$ 84,117
Commercial Healthcare [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				171,332
Initial Cost to Company [Abstract]
Land				24,479
Buildings & Improvements				264,856
Costs capitalized subsequent to acquisition				48,585
Gross amount at which carried at close of period [Abstract]
Land				25,262
Buildings & Improvements				312,658
Total	337,920			337,920
Accumulated Depreciation	(83,558)			(83,558)
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year	337,920
Deductions during year [Abstract]
Balance at close of year	83,558
Commercial Healthcare [Member] | 2800 Medical Building - Minneapolis, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				7,552
Initial Cost to Company [Abstract]
Land				204
Buildings & Improvements				7,135
Costs capitalized subsequent to acquisition				2,547
Gross amount at which carried at close of period [Abstract]
Land				229
Buildings & Improvements				9,657
Total	9,886			9,886
Accumulated Depreciation	$ (3,386)			(3,386)
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	$ 9,886
Deductions during year [Abstract]
Balance at close of year	3,386
Commercial Healthcare [Member] | 2828 Chicago Avenue - Minneapolis, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				11,813
Initial Cost to Company [Abstract]
Land				726
Buildings & Improvements				11,319
Costs capitalized subsequent to acquisition				5,280
Gross amount at which carried at close of period [Abstract]
Land				729
Buildings & Improvements				16,596
Total	17,325			17,325
Accumulated Depreciation	$ (4,614)			(4,614)
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	$ 17,325
Deductions during year [Abstract]
Balance at close of year	4,614
Commercial Healthcare [Member] | Airport Medical - Bloomington, MN [Member]
Initial Cost to Company [Abstract]
Buildings & Improvements				4,678
Costs capitalized subsequent to acquisition				51
Gross amount at which carried at close of period [Abstract]
Land				11
Buildings & Improvements				4,718
Total	4,729			4,729
Accumulated Depreciation	$ (1,848)			(1,848)
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	$ 4,729
Deductions during year [Abstract]
Balance at close of year	1,848
Commercial Healthcare [Member] | Billings 2300 Grant Road - Billings, MT [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				980
Initial Cost to Company [Abstract]
Land				649
Buildings & Improvements				1,216
Gross amount at which carried at close of period [Abstract]
Land				649
Buildings & Improvements				1,216
Total	1,865			1,865
Accumulated Depreciation	$ (176)			(176)
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	176
Commercial Healthcare [Member] | Burnsville 303 Nicollet Medical (Ridgeview) - Burnsville, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				7,903
Initial Cost to Company [Abstract]
Land				1,071
Buildings & Improvements				6,842
Costs capitalized subsequent to acquisition				2,137
Gross amount at which carried at close of period [Abstract]
Land				1,160
Buildings & Improvements				8,890
Total	10,050			10,050
Accumulated Depreciation	$ (1,904)			(1,904)
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	$ 10,050
Deductions during year [Abstract]
Balance at close of year	1,904
Commercial Healthcare [Member] | Burnsville 305 Nicollet Medical (Ridgeview South) - Burnsville, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				4,947
Initial Cost to Company [Abstract]
Land				189
Buildings & Improvements				5,127
Costs capitalized subsequent to acquisition				1,221
Gross amount at which carried at close of period [Abstract]
Land				248
Buildings & Improvements				6,289
Total	6,537			6,537
Accumulated Depreciation	$ (1,261)			(1,261)
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	$ 6,537
Deductions during year [Abstract]
Balance at close of year	1,261
Commercial Healthcare [Member] | Denfeld Clinic - Duluth, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				1,308
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	$ (783)			(783)
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	783
Commercial Healthcare [Member] | Eagan 1440 Duckwood Medical - Eagan, MN [Member]
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	$ (730)			(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	$ 2,624
Deductions during year [Abstract]
Balance at close of year	730
Commercial Healthcare [Member] | Edina 6363 France Medical - Edina, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				11,228
Initial Cost to Company [Abstract]
Buildings & Improvements				12,675
Costs capitalized subsequent to acquisition				3,319
Gross amount at which carried at close of period [Abstract]
Buildings & Improvements				15,994
Total	15,994			15,994
Accumulated Depreciation	$ (4,455)			(4,455)
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	$ 15,994
Deductions during year [Abstract]
Balance at close of year	4,455
Commercial Healthcare [Member] | Edina 6405 France Medical - Edina, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				8,568
Initial Cost to Company [Abstract]
Buildings & Improvements				12,201
Costs capitalized subsequent to acquisition				257
Gross amount at which carried at close of period [Abstract]
Buildings & Improvements				12,458
Total	12,458			12,458
Accumulated Depreciation	$ (3,407)			(3,407)
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	$ 12,458
Deductions during year [Abstract]
Balance at close of year	3,407
Commercial Healthcare [Member] | Edina 6517 Drew Avenue - Edina, MN [Member]
Initial Cost to Company [Abstract]
Land				353
Buildings & Improvements				660
Costs capitalized subsequent to acquisition				27
Gross amount at which carried at close of period [Abstract]
Land				372
Buildings & Improvements				668
Total	1,040			1,040
Accumulated Depreciation	$ (239)			(239)
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	$ 1,040
Deductions during year [Abstract]
Balance at close of year	239
Commercial Healthcare [Member] | Edina 6525 Drew Avenue - Edina, MN [Member]
Initial Cost to Company [Abstract]
Land				388
Buildings & Improvements				117
Gross amount at which carried at close of period [Abstract]
Land				388
Buildings & Improvements				117
Total	505			505
Accumulated Depreciation	$ (13)			(13)
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	13
Commercial Healthcare [Member] | Edina 6525 France SMC II - Edina, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				9,604
Initial Cost to Company [Abstract]
Land				755
Buildings & Improvements				8,054
Costs capitalized subsequent to acquisition				6,156
Gross amount at which carried at close of period [Abstract]
Land				1,040
Buildings & Improvements				13,925
Total	14,965			14,965
Accumulated Depreciation	$ (6,345)			(6,345)
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	$ 14,965
Deductions during year [Abstract]
Balance at close of year	6,345
Commercial Healthcare [Member] | Edina 6545 France SMC I - Edina MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				28,993
Initial Cost to Company [Abstract]
Land				3,480
Buildings & Improvements				30,192
Costs capitalized subsequent to acquisition				14,383
Gross amount at which carried at close of period [Abstract]
Land				3,480
Buildings & Improvements				44,575
Total	48,055			48,055
Accumulated Depreciation	$ (18,379)			(18,379)
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	$ 48,055
Deductions during year [Abstract]
Balance at close of year	18,379
Commercial Healthcare [Member] | Edina 6565 France SMC III - Edina, MN [Member]
Initial Cost to Company [Abstract]
Buildings & Improvements				33,032
Costs capitalized subsequent to acquisition				1,201
Gross amount at which carried at close of period [Abstract]
Buildings & Improvements				34,233
Total	34,233			34,233
Accumulated Depreciation	$ (701)			(701)
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	$ 34,233
Deductions during year [Abstract]
Balance at close of year	701
Commercial Healthcare [Member] | Fresenius - Duluth, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				500
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	$ (458)			(458)
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	458
Commercial Healthcare [Member] | Garden View - St. Paul, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				6,890
Initial Cost to Company [Abstract]
Buildings & Improvements				7,408
Costs capitalized subsequent to acquisition				1,072
Gross amount at which carried at close of period [Abstract]
Land				26
Buildings & Improvements				8,454
Total	8,480			8,480
Accumulated Depreciation	$ (3,001)			(3,001)
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	$ 8,480
Deductions during year [Abstract]
Balance at close of year	3,001
Commercial Healthcare [Member] | Gateway Clinic - Sandstone, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				757
Initial Cost to Company [Abstract]
Land				77
Buildings & Improvements				1,699
Gross amount at which carried at close of period [Abstract]
Land				77
Buildings & Improvements				1,699
Total	1,776			1,776
Accumulated Depreciation	$ (512)			(512)
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	$ 1,776
Deductions during year [Abstract]
Balance at close of year	512
Commercial Healthcare [Member] | Healtheast St John & Woodwinds - Maplewood & Woodbury, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				5,654
Initial Cost to Company [Abstract]
Land				3,239
Buildings & Improvements				18,362
Gross amount at which carried at close of period [Abstract]
Land				3,239
Buildings & Improvements				18,362
Total	21,601			21,601
Accumulated Depreciation	$ (7,326)			(7,326)
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	7,326
Commercial Healthcare [Member] | High Pointe Health Campus - Lake Elmo, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				7,500
Initial Cost to Company [Abstract]
Land				1,305
Buildings & Improvements				10,528
Costs capitalized subsequent to acquisition				2,174
Gross amount at which carried at close of period [Abstract]
Land				1,398
Buildings & Improvements				12,609
Total	14,007			14,007
Accumulated Depreciation	$ (4,226)			(4,226)
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	$ 14,007
Deductions during year [Abstract]
Balance at close of year	4,226
Commercial Healthcare [Member] | Lakeside Medical Plaza - Omaha, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				4,294
Initial Cost to Company [Abstract]
Land				903
Buildings & Improvements				5,210
Gross amount at which carried at close of period [Abstract]
Land				903
Buildings & Improvements				5,210
Total	6,113			6,113
Accumulated Depreciation	$ (92)			(92)
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	$ 6,113
Deductions during year [Abstract]
Balance at close of year	92
Commercial Healthcare [Member] | Mariner Clinic - Superior, WI
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				1,657
Initial Cost to Company [Abstract]
Buildings & Improvements				3,781
Costs capitalized subsequent to acquisition				275
Gross amount at which carried at close of period [Abstract]
Land				20
Buildings & Improvements				4,036
Total	4,056			4,056
Accumulated Depreciation	$ (1,182)			(1,182)
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	$ 4,056
Deductions during year [Abstract]
Balance at close of year	1,182
Commercial Healthcare [Member] | Minneapolis 701 25th Avenue Medical - Minneapolis, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				7,016
Initial Cost to Company [Abstract]
Buildings & Improvements				7,873
Costs capitalized subsequent to acquisition				1,566
Gross amount at which carried at close of period [Abstract]
Buildings & Improvements				9,439
Total	9,439			9,439
Accumulated Depreciation	$ (2,205)			(2,205)
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	2,205
Commercial Healthcare [Member] | Missoula 3050 Great Northern - Missoula, MT [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				997
Initial Cost to Company [Abstract]
Land				640
Buildings & Improvements				1,331
Gross amount at which carried at close of period [Abstract]
Land				640
Buildings & Improvements				1,331
Total	1,971			1,971
Accumulated Depreciation	$ (193)			(193)
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	193
Commercial Healthcare [Member] | Park Dental - Brooklyn Center, MN [Member]
Initial Cost to Company [Abstract]
Land				185
Buildings & Improvements				2,767
Costs capitalized subsequent to acquisition				15
Gross amount at which carried at close of period [Abstract]
Land				200
Buildings & Improvements				2,767
Total	2,967			2,967
Accumulated Depreciation	$ (943)			(943)
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	$ 2,967
Deductions during year [Abstract]
Balance at close of year	943
Commercial Healthcare [Member] | Pavilion I - Duluth, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				4,366
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	$ (2,670)			(2,670)
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	2,670
Commercial Healthcare [Member] | Pavilion II - Duluth, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				8,034
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	$ (6,306)			(6,306)
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	6,306
Commercial Healthcare [Member] | PrairieCare Medical - Brooklyn Park, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				14,982
Initial Cost to Company [Abstract]
Land				2,610
Buildings & Improvements				21,798
Costs capitalized subsequent to acquisition				32
Gross amount at which carried at close of period [Abstract]
Land				2,610
Buildings & Improvements				21,830
Total	24,440			24,440
Accumulated Depreciation	$ (407)			(407)
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	$ 24,440
Deductions during year [Abstract]
Balance at close of year	407
Commercial Healthcare [Member] | Ritchie Medical Plaza - St Paul, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				8,320
Initial Cost to Company [Abstract]
Land				1,615
Buildings & Improvements				7,851
Costs capitalized subsequent to acquisition				4,063
Gross amount at which carried at close of period [Abstract]
Land				1,647
Buildings & Improvements				11,882
Total	13,529			13,529
Accumulated Depreciation	$ (3,422)			(3,422)
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	$ 13,529
Deductions during year [Abstract]
Balance at close of year	3,422
Commercial Healthcare [Member] | St Michael Clinic - St Michael, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				1,736
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	$ (573)			(573)
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	573
Commercial Healthcare [Member] | Trinity at Plaza 16 - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				4,577
Initial Cost to Company [Abstract]
Land				568
Buildings & Improvements				9,009
Costs capitalized subsequent to acquisition				16
Gross amount at which carried at close of period [Abstract]
Land				674
Buildings & Improvements				8,919
Total	9,593			9,593
Accumulated Depreciation	$ (1,049)			(1,049)
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	$ 9,593
Deductions during year [Abstract]
Balance at close of year	1,049
Commercial Healthcare [Member] | Wells Clinic - Hibbing, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				1,156
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	$ (752)			(752)
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	752
Commercial Healthcare [Member] | Wholly Owned Properties [Member]
Reconciliations of total real estate carrying value [Abstract]
Additions	63,605
Other Segments [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				22,313
Initial Cost to Company [Abstract]
Land				13,004
Buildings & Improvements				62,212
Costs capitalized subsequent to acquisition				24,426
Gross amount at which carried at close of period [Abstract]
Land				13,705
Buildings & Improvements				85,937
Total	99,642			99,642
Accumulated Depreciation	(20,175)			(20,175)
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year	99,642
Deductions during year [Abstract]
Balance at close of year	20,175
Other Segments [Member] | 1st Avenue Building - Minot, ND [Member]
Initial Cost to Company [Abstract]
Land				30
Buildings & Improvements				337
Gross amount at which carried at close of period [Abstract]
Land				30
Buildings & Improvements				337
Total	367			367
Accumulated Depreciation	$ (49)			(49)
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	$ 49
Other Segments [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
Other Segments [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
Other Segments [Member] | 17 South Main - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				72
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	$ (205)			(205)
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	205
Other Segments [Member] | Bismarck 715 East Broadway - Bismarck, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				2,041
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	$ (544)			(544)
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	544
Other Segments [Member] | Bloomington 2000 W 94th Street - Bloomington, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				0
Initial Cost to Company [Abstract]
Land				2,133
Buildings & Improvements				4,097
Costs capitalized subsequent to acquisition				1,243
Gross amount at which carried at close of period [Abstract]
Land				2,230
Buildings & Improvements				5,243
Total	7,473			7,473
Accumulated Depreciation	$ (1,649)			(1,649)
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	$ 7,473
Deductions during year [Abstract]
Balance at close of year	1,649
Other Segments [Member] | Dakota West Plaza - Minot , ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				338
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	$ (135)			(135)
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	135
Other Segments [Member] | Grand Forks Carmike - Grand Forks, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				1,176
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	$ (1,270)			(1,270)
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	1,270
Other Segments [Member] | Lexington Commerce Center - Eagan, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				1,504
Initial Cost to Company [Abstract]
Land				453
Buildings & Improvements				4,352
Costs capitalized subsequent to acquisition				2,077
Gross amount at which carried at close of period [Abstract]
Land				492
Buildings & Improvements				6,390
Total	6,882			6,882
Accumulated Depreciation	$ (3,013)			(3,013)
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	$ 6,882
Deductions during year [Abstract]
Balance at close of year	3,013
Other Segments [Member] | Minot 1400 31st Ave - Minot, ND [Member]
Initial Cost to Company [Abstract]
Land				1,026
Buildings & Improvements				6,143
Costs capitalized subsequent to acquisition				4,404
Gross amount at which carried at close of period [Abstract]
Land				1,038
Buildings & Improvements				10,535
Total	11,573			11,573
Accumulated Depreciation	$ (2,904)			(2,904)
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	$ 11,573
Deductions during year [Abstract]
Balance at close of year	2,904
Other Segments [Member] | Minot 2505 16th Street SW - Minot, ND [Member]
Initial Cost to Company [Abstract]
Land				298
Buildings & Improvements				1,724
Costs capitalized subsequent to acquisition				296
Gross amount at which carried at close of period [Abstract]
Land				298
Buildings & Improvements				2,020
Total	2,318			2,318
Accumulated Depreciation	$ (351)			(351)
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	$ 2,318
Deductions during year [Abstract]
Balance at close of year	351
Other Segments [Member] | Minot Arrowhead - Minot, ND [Member]
Initial Cost to Company [Abstract]
Land				100
Buildings & Improvements				3,216
Costs capitalized subsequent to acquisition				5,554
Gross amount at which carried at close of period [Abstract]
Land				176
Buildings & Improvements				8,694
Total	8,870			8,870
Accumulated Depreciation	$ (2,402)			(2,402)
Date of Construction or Acquisition	1973
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	$ 8,870
Deductions during year [Abstract]
Balance at close of year	2,402
Other Segments [Member] | Minot IPS - Minot, ND [Member]
Initial Cost to Company [Abstract]
Land				416
Buildings & Improvements				5,952
Gross amount at which carried at close of period [Abstract]
Land				416
Buildings & Improvements				5,952
Total	6,368			6,368
Accumulated Depreciation	$ (537)			(537)
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	$ 6,368
Deductions during year [Abstract]
Balance at close of year	537
Other Segments [Member] | Minot Southgate Wells Fargo Bank - Minot, ND [Member]
Initial Cost to Company [Abstract]
Land				992
Buildings & Improvements				2,237
Gross amount at which carried at close of period [Abstract]
Land				992
Buildings & Improvements				2,237
Total	3,229			3,229
Accumulated Depreciation	$ (81)			(81)
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	$ 3,229
Deductions during year [Abstract]
Balance at close of year	81
Other Segments [Member] | Minot Southgate Retail - Minot, ND [Member]
Initial Cost to Company [Abstract]
Land				889
Buildings & Improvements				1,734
Gross amount at which carried at close of period [Abstract]
Land				889
Buildings & Improvements				1,734
Total	2,623			2,623
Accumulated Depreciation	$ (24)			(24)
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	$ 2,623
Deductions during year [Abstract]
Balance at close of year	24
Other Segments [Member] | Plaza 16 - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				6,916
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	$ (2,410)			(2,410)
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	2,410
Other Segments [Member] | Roseville 3075 Long Lake Road - Roseville, MN [Member]
Initial Cost to Company [Abstract]
Land				810
Buildings & Improvements				10,244
Costs capitalized subsequent to acquisition				1,771
Gross amount at which carried at close of period [Abstract]
Land				810
Buildings & Improvements				12,015
Total	12,825			12,825
Accumulated Depreciation	$ (507)			(507)
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	$ 12,825
Deductions during year [Abstract]
Balance at close of year	507
Other Segments [Member] | Urbandale 3900 106th Street - Urbandale, IA [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				10,266
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	$ (2,955)			(2,955)
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	2,955
Other Segments [Member] | Woodbury 1865 Woodlane - Woodbury, MN [Member]
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	$ (1,139)			(1,139)
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	1,139
Other Segments [Member] | Wholly Owned Properties [Member]
Reconciliations of total real estate carrying value [Abstract]
Additions	2,623	$ 12,223
Subtotal [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances				817,074
Initial Cost to Company [Abstract]
Land				117,284
Buildings & Improvements				1,340,271
Costs capitalized subsequent to acquisition				223,916
Gross amount at which carried at close of period [Abstract]
Land				136,979
Buildings & Improvements				1,544,492
Total	1,681,471			1,681,471
Accumulated Depreciation	(312,889)			$ (312,889)
Reconciliations of total real estate carrying value [Abstract]
Balance at close of year	1,681,471
Deductions during year [Abstract]
Balance at close of year	$ 312,889