SCHEDULE III - REAL ESTATE AND ACCUMULATED DEPRECIATION (Details) (USD $)	12 Months Ended
	Apr. 30, 2014		Apr. 30, 2013		Apr. 30, 2012
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	$ 997,689,000
Initial Cost to Company [Abstract]
Land	219,439,000
Buildings & Improvements	1,606,537,000
Costs capitalized subsequent to acquisition	297,528,000
Gross amount at which carried at close of period [Abstract]
Land	241,134,000
Buildings & Improvements	1,882,370,000
Total	2,123,504,000	[1]
Accumulated Depreciation	(424,288,000)	[1]
Maximum borrowing capacity	72,000,000
Advances under the facility specified as percentage of value of properties provided as security (in hundredths)	60.00%
Deductions during year [Abstract]
Balance at close of year	2,123,504,000	[1]
Deductions during year [Abstract]
Balance at close of year	424,288,000	[1]
Total real estate investments	1,699,216,000		1,680,834,000	[2]	1,557,108,000	[1]
Net basis of real estate investments for federal income tax purposes	1,500,000,000		1,500,000,000		1,400,000,000
Granite Corporate Center - St. Cloud, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	5,492,000
Initial Cost to Company [Abstract]
Land	588,000
Buildings & Improvements	7,808,000
Costs capitalized subsequent to acquisition	1,368,000
Gross amount at which carried at close of period [Abstract]
Land	727,000
Buildings & Improvements	9,037,000
Accumulated Depreciation	(3,199,000)
Year of Construction or Acquisition	2001
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	3,199,000
Unimproved Land [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	20,815,000
Buildings & Improvements	0
Costs capitalized subsequent to acquisition	2,049,000
Gross amount at which carried at close of period [Abstract]
Land	22,864,000
Buildings & Improvements	0
Total	22,864,000		21,503,000		10,990,000
Accumulated Depreciation	0
Year of Construction or Acquisition	2014
Reconciliations of total real estate carrying value [Abstract]
Balance at beginning of year	21,503,000		10,990,000		6,550,000
Additions during year [Abstract]
Acquisitions	3,022,000		13,329,000		4,600,000
Improvements and Other	1,209,000		854,000		10,000
Deductions during year [Abstract]
Transfers	(2,870,000)		(3,670,000)		(170,000)
Balance at close of year	22,864,000		21,503,000		10,990,000
Deductions during year [Abstract]
Balance at close of year	0
Unimproved Land [Member] | Deer Ridge - Jamestown, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	711,000
Buildings & Improvements	0
Costs capitalized subsequent to acquisition	0
Gross amount at which carried at close of period [Abstract]
Land	711,000
Buildings & Improvements	0
Total	711,000
Accumulated Depreciation	0
Year of Construction or Acquisition	2013
Deductions during year [Abstract]
Balance at close of year	711,000
Deductions during year [Abstract]
Balance at close of year	0
Unimproved Land [Member] | Minot Wells Fargo Bank - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	992,000
Buildings & Improvements	0
Costs capitalized subsequent to acquisition	0
Gross amount at which carried at close of period [Abstract]
Land	992,000
Buildings & Improvements	0
Total	992,000
Accumulated Depreciation	0
Year of Construction or Acquisition	2013
Deductions during year [Abstract]
Balance at close of year	992,000
Deductions during year [Abstract]
Balance at close of year	0
Unimproved Land [Member] | Rapid City Unimproved- Rapid City, SD [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	1,376,000
Buildings & Improvements	0
Costs capitalized subsequent to acquisition	0
Gross amount at which carried at close of period [Abstract]
Land	1,376,000
Buildings & Improvements	0
Total	1,376,000
Accumulated Depreciation	0
Year of Construction or Acquisition	2014
Deductions during year [Abstract]
Balance at close of year	1,376,000
Deductions during year [Abstract]
Balance at close of year	0
Unimproved Land [Member] | Legends at Heritage Place - Sartell, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	537,000
Buildings & Improvements	0
Costs capitalized subsequent to acquisition	0
Gross amount at which carried at close of period [Abstract]
Land	537,000
Buildings & Improvements	0
Total	537,000
Accumulated Depreciation	0
Year of Construction or Acquisition	2013
Deductions during year [Abstract]
Balance at close of year	537,000
Deductions during year [Abstract]
Balance at close of year	0
Unimproved Land [Member] | Spring Creek Fruitland - Fruitland, ID [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	339,000
Buildings & Improvements	0
Costs capitalized subsequent to acquisition	0
Gross amount at which carried at close of period [Abstract]
Land	339,000
Buildings & Improvements	0
Total	339,000
Accumulated Depreciation	0
Deductions during year [Abstract]
Balance at close of year	339,000
Deductions during year [Abstract]
Balance at close of year	0
Unimproved Land [Member] | Badger Hills Rochester, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	1,050,000
Buildings & Improvements	0
Costs capitalized subsequent to acquisition	0
Gross amount at which carried at close of period [Abstract]
Land	1,050,000
Buildings & Improvements	0
Total	1,050,000
Accumulated Depreciation	0
Year of Construction or Acquisition	2012
Deductions during year [Abstract]
Balance at close of year	1,050,000
Deductions during year [Abstract]
Balance at close of year	0
Unimproved Land [Member] | Bismarck 4916 - Bismarck, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	3,250,000
Buildings & Improvements	0
Costs capitalized subsequent to acquisition	0
Gross amount at which carried at close of period [Abstract]
Land	3,250,000
Buildings & Improvements	0
Total	3,250,000
Accumulated Depreciation	0
Year of Construction or Acquisition	2013
Deductions during year [Abstract]
Balance at close of year	3,250,000
Deductions during year [Abstract]
Balance at close of year	0
Unimproved Land [Member] | Bismarck 700 E Main - Bismarck, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	314,000
Buildings & Improvements	0
Costs capitalized subsequent to acquisition	562,000
Gross amount at which carried at close of period [Abstract]
Land	876,000
Buildings & Improvements	0
Total	876,000
Accumulated Depreciation	0
Year of Construction or Acquisition	2008
Deductions during year [Abstract]
Balance at close of year	876,000
Deductions during year [Abstract]
Balance at close of year	0
Unimproved Land [Member] | Eagan - Eagan, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	423,000
Buildings & Improvements	0
Costs capitalized subsequent to acquisition	0
Gross amount at which carried at close of period [Abstract]
Land	423,000
Buildings & Improvements	0
Total	423,000
Accumulated Depreciation	0
Year of Construction or Acquisition	2006
Deductions during year [Abstract]
Balance at close of year	423,000
Deductions during year [Abstract]
Balance at close of year	0
Unimproved Land [Member] | Georgetown Square - Grand Chute, WI [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	1,860,000
Buildings & Improvements	0
Costs capitalized subsequent to acquisition	0
Gross amount at which carried at close of period [Abstract]
Land	1,860,000
Buildings & Improvements	0
Total	1,860,000
Accumulated Depreciation	0
Year of Construction or Acquisition	2006
Deductions during year [Abstract]
Balance at close of year	1,860,000
Deductions during year [Abstract]
Balance at close of year	0
Unimproved Land [Member] | Grand Forks Grand Forks, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	4,278,000
Buildings & Improvements	0
Costs capitalized subsequent to acquisition	0
Gross amount at which carried at close of period [Abstract]
Land	4,278,000
Buildings & Improvements	0
Total	4,278,000
Accumulated Depreciation	0
Year of Construction or Acquisition	2012
Deductions during year [Abstract]
Balance at close of year	4,278,000
Deductions during year [Abstract]
Balance at close of year	0
Unimproved Land [Member] | Kalispell - Kalispell, MT [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	1,400,000
Buildings & Improvements	0
Costs capitalized subsequent to acquisition	24,000
Gross amount at which carried at close of period [Abstract]
Land	1,424,000
Buildings & Improvements	0
Total	1,424,000
Accumulated Depreciation	0
Year of Construction or Acquisition	2003
Deductions during year [Abstract]
Balance at close of year	1,424,000
Deductions during year [Abstract]
Balance at close of year	0
Unimproved Land [Member] | Isanti Unimproved - Isanti, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	58,000
Buildings & Improvements	0
Costs capitalized subsequent to acquisition	0
Gross amount at which carried at close of period [Abstract]
Land	58,000
Buildings & Improvements	0
Total	58,000
Accumulated Depreciation	0
Year of Construction or Acquisition	2014
Deductions during year [Abstract]
Balance at close of year	58,000
Deductions during year [Abstract]
Balance at close of year	0
Unimproved Land [Member] | Minot Southgate Lot 4 Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	890,000
Buildings & Improvements	0
Costs capitalized subsequent to acquisition	0
Gross amount at which carried at close of period [Abstract]
Land	890,000
Buildings & Improvements	0
Total	890,000
Accumulated Depreciation	0
Year of Construction or Acquisition	2013
Deductions during year [Abstract]
Balance at close of year	890,000
Deductions during year [Abstract]
Balance at close of year	0
Unimproved Land [Member] | Monticello - Monticello, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	115,000
Buildings & Improvements	0
Costs capitalized subsequent to acquisition	2,000
Gross amount at which carried at close of period [Abstract]
Land	117,000
Buildings & Improvements	0
Total	117,000
Accumulated Depreciation	0
Year of Construction or Acquisition	2006
Deductions during year [Abstract]
Balance at close of year	117,000
Deductions during year [Abstract]
Balance at close of year	0
Unimproved Land [Member] | Renaissance Heights - Williston ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	2,229,000
Buildings & Improvements	0
Costs capitalized subsequent to acquisition	1,348,000
Gross amount at which carried at close of period [Abstract]
Land	3,577,000
Buildings & Improvements	0
Total	3,577,000
Accumulated Depreciation	0
Year of Construction or Acquisition	2012
Deductions during year [Abstract]
Balance at close of year	3,577,000
Deductions during year [Abstract]
Balance at close of year	0
Unimproved Land [Member] | River Falls - River Falls, WI [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	176,000
Buildings & Improvements	0
Costs capitalized subsequent to acquisition	4,000
Gross amount at which carried at close of period [Abstract]
Land	180,000
Buildings & Improvements	0
Total	180,000
Accumulated Depreciation	0
Year of Construction or Acquisition	2003
Deductions during year [Abstract]
Balance at close of year	180,000
Deductions during year [Abstract]
Balance at close of year	0
Unimproved Land [Member] | Urbandale - Urbandale, IA [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	5,000
Buildings & Improvements	0
Costs capitalized subsequent to acquisition	109,000
Gross amount at which carried at close of period [Abstract]
Land	114,000
Buildings & Improvements	0
Total	114,000
Accumulated Depreciation	0
Year of Construction or Acquisition	2009
Deductions during year [Abstract]
Balance at close of year	114,000
Deductions during year [Abstract]
Balance at close of year	0
Unimproved Land [Member] | Weston - Weston, WI [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	812,000
Buildings & Improvements	0
Costs capitalized subsequent to acquisition	0
Gross amount at which carried at close of period [Abstract]
Land	812,000
Buildings & Improvements	0
Total	812,000
Accumulated Depreciation	0
Year of Construction or Acquisition	2006
Deductions during year [Abstract]
Balance at close of year	812,000
Deductions during year [Abstract]
Balance at close of year	0
Development in Progress [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	13,253,000
Buildings & Improvements	64,949,000
Costs capitalized subsequent to acquisition	26,407,000
Gross amount at which carried at close of period [Abstract]
Land	13,253,000
Buildings & Improvements	91,356,000
Total	104,609,000		46,782,000		27,599,000
Accumulated Depreciation	0
Reconciliations of total real estate carrying value [Abstract]
Balance at beginning of year	46,782,000		27,599,000		9,693,000
Additions during year [Abstract]
Acquisitions	2,079,000		9,177,000		2,718,000
Improvements and Other	123,240,000		52,970,000		40,358,000
Deductions during year [Abstract]
Involuntary conversion	(7,052,000)		0		0
Transfers	2,870,000		0		0
Development placed in service	(63,210,000)	[3]	(42,964,000)	[3]	(23,434,000)	[3]
Other	(100,000)	[4]	0	[4]	(1,736,000)	[4]
Balance at close of year	104,609,000		46,782,000		27,599,000
Deductions during year [Abstract]
Balance at close of year	0
Development in Progress [Member] | Other [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	0
Buildings & Improvements	0
Costs capitalized subsequent to acquisition	2,496,000
Gross amount at which carried at close of period [Abstract]
Land	0
Buildings & Improvements	2,496,000
Total	2,496,000
Accumulated Depreciation	0
Year of Construction or Acquisition
Deductions during year [Abstract]
Balance at close of year	2,496,000
Deductions during year [Abstract]
Balance at close of year	0
Development in Progress [Member] | Renaissance Heights I - Williston ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	2,464,000
Buildings & Improvements	23,900,000
Costs capitalized subsequent to acquisition	1,165,000
Gross amount at which carried at close of period [Abstract]
Land	2,464,000
Buildings & Improvements	25,065,000
Total	27,529,000
Accumulated Depreciation	0
Year of Construction or Acquisition
Deductions during year [Abstract]
Balance at close of year	27,529,000
Deductions during year [Abstract]
Balance at close of year	0
Development in Progress [Member] | Arcata - Golden Valley, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	2,088,000
Buildings & Improvements	8,974,000
Costs capitalized subsequent to acquisition	1,956,000
Gross amount at which carried at close of period [Abstract]
Land	2,088,000
Buildings & Improvements	10,930,000
Total	13,018,000
Accumulated Depreciation	0
Year of Construction or Acquisition	2013
Deductions during year [Abstract]
Balance at close of year	13,018,000
Deductions during year [Abstract]
Balance at close of year	0
Development in Progress [Member] | Cardinal Point - Grand Forks, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	1,600,000
Buildings & Improvements	0
Costs capitalized subsequent to acquisition	5,229,000
Gross amount at which carried at close of period [Abstract]
Land	1,600,000
Buildings & Improvements	5,229,000
Total	6,829,000
Accumulated Depreciation	0
Year of Construction or Acquisition	2013
Deductions during year [Abstract]
Balance at close of year	6,829,000
Deductions during year [Abstract]
Balance at close of year	0
Development in Progress [Member] | Chateau II - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	240,000
Buildings & Improvements	1,842,000
Costs capitalized subsequent to acquisition	16,000
Gross amount at which carried at close of period [Abstract]
Land	240,000
Buildings & Improvements	1,858,000
Total	2,098,000
Accumulated Depreciation	0
Year of Construction or Acquisition	2013
Deductions during year [Abstract]
Balance at close of year	2,098,000
Deductions during year [Abstract]
Balance at close of year	0
Development in Progress [Member] | Commons at Southgate - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	3,691,000
Buildings & Improvements	22,819,000
Costs capitalized subsequent to acquisition	1,555,000
Gross amount at which carried at close of period [Abstract]
Land	3,691,000
Buildings & Improvements	24,374,000
Total	28,065,000
Accumulated Depreciation	0
Year of Construction or Acquisition	2013
Deductions during year [Abstract]
Balance at close of year	28,065,000
Deductions during year [Abstract]
Balance at close of year	0
Development in Progress [Member] | Cypress Court - Undev, St. Cloud, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	447,000
Buildings & Improvements	5,000
Costs capitalized subsequent to acquisition	1,128,000
Gross amount at which carried at close of period [Abstract]
Land	447,000
Buildings & Improvements	1,133,000
Total	1,580,000
Accumulated Depreciation	0
Year of Construction or Acquisition	2012
Deductions during year [Abstract]
Balance at close of year	1,580,000
Deductions during year [Abstract]
Balance at close of year	0
Development in Progress [Member] | RED 20 - Minneapolis, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	823,000
Buildings & Improvements	7,293,000
Costs capitalized subsequent to acquisition	898,000
Gross amount at which carried at close of period [Abstract]
Land	823,000
Buildings & Improvements	8,191,000
Total	9,014,000
Accumulated Depreciation	0
Year of Construction or Acquisition	2012
Deductions during year [Abstract]
Balance at close of year	9,014,000
Deductions during year [Abstract]
Balance at close of year	0
Development in Progress [Member] | Dakota Commons - Williston, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	1,900,000
Buildings & Improvements	116,000
Costs capitalized subsequent to acquisition	11,964,000
Gross amount at which carried at close of period [Abstract]
Land	1,900,000
Buildings & Improvements	12,080,000
Total	13,980,000
Accumulated Depreciation	0
Year of Construction or Acquisition	2013
Deductions during year [Abstract]
Balance at close of year	13,980,000
Deductions during year [Abstract]
Balance at close of year	0
Wholly Owned Properties [Member]
Gross amount at which carried at close of period [Abstract]
Total	1,996,031,000	[3]	2,032,970,000	[3]	1,892,009,000	[3]
Accumulated Depreciation	(424,288,000)		(420,421,000)		(373,490,000)
Reconciliations of total real estate carrying value [Abstract]
Balance at beginning of year	2,032,970,000	[3]	1,892,009,000	[3]	1,770,798,000
Additions during year [Abstract]
Improvements and Other	34,637,000		36,375,000		35,176,000
Total Additions	2,169,729,000		2,060,505,000		1,903,131,000
Deductions during year [Abstract]
Cost of real estate sold	(85,030,000)		(21,953,000)		(3,498,000)
Impairment charge	(43,189,000)		(305,000)		(127,000)
Write down of asset and accumulated depreciation on impaired assets	(31,688,000)		0		0
Transfers	(10,307,000)		(1,893,000)		(1,288,000)
Other	(3,484,000)	[5]	(3,384,000)	[5]	(6,209,000)	[5]
Balance at close of year	1,996,031,000	[3]	2,032,970,000	[3]	1,892,009,000	[3]
Reconciliations of accumulated depreciation/amortization [Abstract]
Balance at beginning of year	420,421,000		373,490,000		328,952,000
Additions during year [Abstract]
Provisions for depreciation	57,575,000		56,611,000		51,093,000
Deductions during year [Abstract]
Accumulated depreciation on real estate sold	(19,413,000)		(6,444,000)		(758,000)
Write down of asset and accumulated depreciation on impaired assets	(31,688,000)		0		0
Other	(2,607,000)	[5]	(3,236,000)	[5]	(5,797,000)	[5]
Balance at close of year	424,288,000		420,421,000		373,490,000
Multi-Family Residential [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	384,695,000
Initial Cost to Company [Abstract]
Land	52,345,000
Buildings & Improvements	578,841,000
Costs capitalized subsequent to acquisition	122,545,000
Gross amount at which carried at close of period [Abstract]
Land	66,722,000
Buildings & Improvements	687,009,000
Total	753,731,000
Accumulated Depreciation	(158,100,000)
Deductions during year [Abstract]
Balance at close of year	753,731,000
Deductions during year [Abstract]
Balance at close of year	158,100,000
Multi-Family Residential [Member] | 11th Street 3 Plex - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	87,000
Initial Cost to Company [Abstract]
Land	11,000
Buildings & Improvements	53,000
Costs capitalized subsequent to acquisition	17,000
Gross amount at which carried at close of period [Abstract]
Land	19,000
Buildings & Improvements	62,000
Total	81,000
Accumulated Depreciation	(10,000)
Year of Construction or Acquisition	2008
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	81,000
Deductions during year [Abstract]
Balance at close of year	10,000
Multi-Family Residential [Member] | 4th Street 4 Plex - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	101,000
Initial Cost to Company [Abstract]
Land	15,000
Buildings & Improvements	74,000
Costs capitalized subsequent to acquisition	27,000
Gross amount at which carried at close of period [Abstract]
Land	23,000
Buildings & Improvements	93,000
Total	116,000
Accumulated Depreciation	(14,000)
Year of Construction or Acquisition	2008
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	116,000
Deductions during year [Abstract]
Balance at close of year	14,000
Multi-Family Residential [Member] | Alps Park - Rapid City, SD [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	4,030,000
Initial Cost to Company [Abstract]
Land	287,000
Buildings & Improvements	5,551,000
Costs capitalized subsequent to acquisition	84,000
Gross amount at which carried at close of period [Abstract]
Land	289,000
Buildings & Improvements	5,633,000
Total	5,922,000
Accumulated Depreciation	(140,000)
Year of Construction or Acquisition	2013
Deductions during year [Abstract]
Balance at close of year	5,922,000
Deductions during year [Abstract]
Balance at close of year	140,000
Multi-Family Residential [Member] | Apartments on Main - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	666,000
Initial Cost to Company [Abstract]
Land	158,000
Buildings & Improvements	1,123,000
Costs capitalized subsequent to acquisition	31,000
Gross amount at which carried at close of period [Abstract]
Land	181,000
Buildings & Improvements	1,131,000
Total	1,312,000
Accumulated Depreciation	(198,000)
Year of Construction or Acquisition	1987
Deductions during year [Abstract]
Balance at close of year	1,312,000
Deductions during year [Abstract]
Balance at close of year	198,000
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	20 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	3,922,000
Initial Cost to Company [Abstract]
Land	350,000
Buildings & Improvements	6,625,000
Costs capitalized subsequent to acquisition	1,610,000
Gross amount at which carried at close of period [Abstract]
Land	790,000
Buildings & Improvements	7,795,000
Total	8,585,000
Accumulated Depreciation	(1,807,000)
Year of Construction or Acquisition	2006
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	8,585,000
Deductions during year [Abstract]
Balance at close of year	1,807,000
Multi-Family Residential [Member] | Ashland - Grand Forks, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	5,615,000
Initial Cost to Company [Abstract]
Land	741,000
Buildings & Improvements	7,569,000
Costs capitalized subsequent to acquisition	90,000
Gross amount at which carried at close of period [Abstract]
Land	762,000
Buildings & Improvements	7,638,000
Total	8,400,000
Accumulated Depreciation	(460,000)
Year of Construction or Acquisition	2012
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	8,400,000
Deductions during year [Abstract]
Balance at close of year	460,000
Multi-Family Residential [Member] | Boulder Court - Eagan, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	2,990,000
Initial Cost to Company [Abstract]
Land	1,067,000
Buildings & Improvements	5,498,000
Costs capitalized subsequent to acquisition	2,853,000
Gross amount at which carried at close of period [Abstract]
Land	1,299,000
Buildings & Improvements	8,119,000
Total	9,418,000
Accumulated Depreciation	(2,280,000)
Year of Construction or Acquisition	2003
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	9,418,000
Deductions during year [Abstract]
Balance at close of year	2,280,000
Multi-Family Residential [Member] | Brookfield Village - Topeka, KS [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	5,303,000
Initial Cost to Company [Abstract]
Land	509,000
Buildings & Improvements	6,698,000
Costs capitalized subsequent to acquisition	1,393,000
Gross amount at which carried at close of period [Abstract]
Land	674,000
Buildings & Improvements	7,926,000
Total	8,600,000
Accumulated Depreciation	(2,165,000)
Year of Construction or Acquisition	2003
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	8,600,000
Deductions during year [Abstract]
Balance at close of year	2,165,000
Multi-Family Residential [Member] | Brooklyn Heights - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	749,000
Initial Cost to Company [Abstract]
Land	145,000
Buildings & Improvements	1,450,000
Costs capitalized subsequent to acquisition	834,000
Gross amount at which carried at close of period [Abstract]
Land	217,000
Buildings & Improvements	2,212,000
Total	2,429,000
Accumulated Depreciation	(875,000)
Year of Construction or Acquisition	1997
Deductions during year [Abstract]
Balance at close of year	2,429,000
Deductions during year [Abstract]
Balance at close of year	875,000
Multi-Family Residential [Member] | Brooklyn Heights - Minot, ND [Member] | Minimum [Member]
Gross amount at which carried at close of period [Abstract]
Life on which depreciation in latest income statement is computed	12 years
Multi-Family Residential [Member] | Brooklyn Heights - Minot, ND [Member] | Maximum [Member]
Gross amount at which carried at close of period [Abstract]
Life on which depreciation in latest income statement is computed	40 years
Multi-Family Residential [Member] | Campus Center - St. Cloud, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	1,206,000
Initial Cost to Company [Abstract]
Land	395,000
Buildings & Improvements	2,244,000
Costs capitalized subsequent to acquisition	208,000
Gross amount at which carried at close of period [Abstract]
Land	405,000
Buildings & Improvements	2,442,000
Total	2,847,000
Accumulated Depreciation	(459,000)
Year of Construction or Acquisition	2007
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	2,847,000
Deductions during year [Abstract]
Balance at close of year	459,000
Multi-Family Residential [Member] | Campus Heights - St. Cloud, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	110,000
Buildings & Improvements	628,000
Costs capitalized subsequent to acquisition	93,000
Gross amount at which carried at close of period [Abstract]
Land	124,000
Buildings & Improvements	707,000
Total	831,000
Accumulated Depreciation	(136,000)
Year of Construction or Acquisition	2007
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	831,000
Deductions during year [Abstract]
Balance at close of year	136,000
Multi-Family Residential [Member] | Campus Knoll - St. Cloud, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	804,000
Initial Cost to Company [Abstract]
Land	266,000
Buildings & Improvements	1,512,000
Costs capitalized subsequent to acquisition	120,000
Gross amount at which carried at close of period [Abstract]
Land	279,000
Buildings & Improvements	1,619,000
Total	1,898,000
Accumulated Depreciation	(312,000)
Year of Construction or Acquisition	2007
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	1,898,000
Deductions during year [Abstract]
Balance at close of year	312,000
Multi-Family Residential [Member] | Campus Plaza - St. Cloud, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	54,000
Buildings & Improvements	311,000
Costs capitalized subsequent to acquisition	69,000
Gross amount at which carried at close of period [Abstract]
Land	60,000
Buildings & Improvements	374,000
Total	434,000
Accumulated Depreciation	(72,000)
Year of Construction or Acquisition	2007
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	434,000
Deductions during year [Abstract]
Balance at close of year	72,000
Multi-Family Residential [Member] | Campus Side - St. Cloud, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	107,000
Buildings & Improvements	615,000
Costs capitalized subsequent to acquisition	140,000
Gross amount at which carried at close of period [Abstract]
Land	118,000
Buildings & Improvements	744,000
Total	862,000
Accumulated Depreciation	(140,000)
Year of Construction or Acquisition	2007
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	862,000
Deductions during year [Abstract]
Balance at close of year	140,000
Multi-Family Residential [Member] | Campus View - St. Cloud, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	107,000
Buildings & Improvements	615,000
Costs capitalized subsequent to acquisition	120,000
Gross amount at which carried at close of period [Abstract]
Land	113,000
Buildings & Improvements	729,000
Total	842,000
Accumulated Depreciation	(136,000)
Year of Construction or Acquisition	2007
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	842,000
Deductions during year [Abstract]
Balance at close of year	136,000
Multi-Family Residential [Member] | Canyon Lake - Rapid City, SD [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	2,894,000
Initial Cost to Company [Abstract]
Land	305,000
Buildings & Improvements	3,958,000
Costs capitalized subsequent to acquisition	1,579,000
Gross amount at which carried at close of period [Abstract]
Land	374,000
Buildings & Improvements	5,468,000
Total	5,842,000
Accumulated Depreciation	(1,548,000)
Year of Construction or Acquisition	2001
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	5,842,000
Deductions during year [Abstract]
Balance at close of year	1,548,000
Multi-Family Residential [Member] | Castlerock - Billings, MT [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	6,677,000
Initial Cost to Company [Abstract]
Land	736,000
Buildings & Improvements	4,864,000
Costs capitalized subsequent to acquisition	1,982,000
Gross amount at which carried at close of period [Abstract]
Land	964,000
Buildings & Improvements	6,618,000
Total	7,582,000
Accumulated Depreciation	(2,504,000)
Year of Construction or Acquisition	1998
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	7,582,000
Deductions during year [Abstract]
Balance at close of year	2,504,000
Multi-Family Residential [Member] | Chateau I - Minot ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	61,000
Buildings & Improvements	5,663,000
Costs capitalized subsequent to acquisition	561,000
Gross amount at which carried at close of period [Abstract]
Land	67,000
Buildings & Improvements	6,218,000
Total	6,285,000
Accumulated Depreciation	(569,000)
Year of Construction or Acquisition	2013
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	6,285,000
Deductions during year [Abstract]
Balance at close of year	569,000
Multi-Family Residential [Member] | Cimarron Hills - Omaha, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	4,806,000
Initial Cost to Company [Abstract]
Land	706,000
Buildings & Improvements	9,588,000
Costs capitalized subsequent to acquisition	4,198,000
Gross amount at which carried at close of period [Abstract]
Land	1,302,000
Buildings & Improvements	13,190,000
Total	14,492,000
Accumulated Depreciation	(4,307,000)
Year of Construction or Acquisition	2001
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	14,492,000
Deductions during year [Abstract]
Balance at close of year	4,307,000
Multi-Family Residential [Member] | Colonial Villa - Burnsville, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	5,980,000
Initial Cost to Company [Abstract]
Land	2,401,000
Buildings & Improvements	11,515,000
Costs capitalized subsequent to acquisition	6,416,000
Gross amount at which carried at close of period [Abstract]
Land	2,827,000
Buildings & Improvements	17,505,000
Total	20,332,000
Accumulated Depreciation	(4,547,000)
Year of Construction or Acquisition	2003
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	20,332,000
Deductions during year [Abstract]
Balance at close of year	4,547,000
Multi-Family Residential [Member] | Colony - Lincoln, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	13,565,000
Initial Cost to Company [Abstract]
Land	1,515,000
Buildings & Improvements	15,730,000
Costs capitalized subsequent to acquisition	389,000
Gross amount at which carried at close of period [Abstract]
Land	1,544,000
Buildings & Improvements	16,090,000
Total	17,634,000
Accumulated Depreciation	(829,000)
Year of Construction or Acquisition	2012
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	17,634,000
Deductions during year [Abstract]
Balance at close of year	829,000
Multi-Family Residential [Member] | Colton Heights - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	421,000
Initial Cost to Company [Abstract]
Land	80,000
Buildings & Improvements	672,000
Costs capitalized subsequent to acquisition	414,000
Gross amount at which carried at close of period [Abstract]
Land	116,000
Buildings & Improvements	1,050,000
Total	1,166,000
Accumulated Depreciation	(737,000)
Year of Construction or Acquisition	1984
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	1,166,000
Deductions during year [Abstract]
Balance at close of year	737,000
Multi-Family Residential [Member] | Cornerstone - St. Cloud, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	54,000
Buildings & Improvements	311,000
Costs capitalized subsequent to acquisition	71,000
Gross amount at which carried at close of period [Abstract]
Land	57,000
Buildings & Improvements	379,000
Total	436,000
Accumulated Depreciation	(74,000)
Year of Construction or Acquisition	2007
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	436,000
Deductions during year [Abstract]
Balance at close of year	74,000
Multi-Family Residential [Member] | Cottage West Twin Homes - Sioux Falls, SD [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	3,646,000
Initial Cost to Company [Abstract]
Land	968,000
Buildings & Improvements	3,762,000
Costs capitalized subsequent to acquisition	373,000
Gross amount at which carried at close of period [Abstract]
Land	1,005,000
Buildings & Improvements	4,098,000
Total	5,103,000
Accumulated Depreciation	(265,000)
Year of Construction or Acquisition	2011
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	5,103,000
Deductions during year [Abstract]
Balance at close of year	265,000
Multi-Family Residential [Member] | Cottonwood - Bismarck, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	15,803,000
Initial Cost to Company [Abstract]
Land	1,056,000
Buildings & Improvements	17,372,000
Costs capitalized subsequent to acquisition	3,146,000
Gross amount at which carried at close of period [Abstract]
Land	1,354,000
Buildings & Improvements	20,220,000
Total	21,574,000
Accumulated Depreciation	(6,372,000)
Year of Construction or Acquisition	1997
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	21,574,000
Deductions during year [Abstract]
Balance at close of year	6,372,000
Multi-Family Residential [Member] | Country Meadows - Billings, MT [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	6,678,000
Initial Cost to Company [Abstract]
Land	491,000
Buildings & Improvements	7,809,000
Costs capitalized subsequent to acquisition	1,344,000
Gross amount at which carried at close of period [Abstract]
Land	535,000
Buildings & Improvements	9,109,000
Total	9,644,000
Accumulated Depreciation	(3,507,000)
Year of Construction or Acquisition	1995
Deductions during year [Abstract]
Balance at close of year	9,644,000
Deductions during year [Abstract]
Balance at close of year	3,507,000
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	3,917,000
Initial Cost to Company [Abstract]
Land	235,000
Buildings & Improvements	4,290,000
Costs capitalized subsequent to acquisition	1,576,000
Gross amount at which carried at close of period [Abstract]
Land	495,000
Buildings & Improvements	5,606,000
Total	6,101,000
Accumulated Depreciation	(2,740,000)
Year of Construction or Acquisition	1994
Deductions during year [Abstract]
Balance at close of year	6,101,000
Deductions during year [Abstract]
Balance at close of year	2,740,000
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	2,629,000
Initial Cost to Company [Abstract]
Land	261,000
Buildings & Improvements	3,289,000
Costs capitalized subsequent to acquisition	194,000
Gross amount at which carried at close of period [Abstract]
Land	266,000
Buildings & Improvements	3,478,000
Total	3,744,000
Accumulated Depreciation	(368,000)
Year of Construction or Acquisition	2010
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	3,744,000
Deductions during year [Abstract]
Balance at close of year	368,000
Multi-Family Residential [Member] | Crown Colony - Topeka, KS [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	8,220,000
Initial Cost to Company [Abstract]
Land	620,000
Buildings & Improvements	9,956,000
Costs capitalized subsequent to acquisition	2,220,000
Gross amount at which carried at close of period [Abstract]
Land	857,000
Buildings & Improvements	11,939,000
Total	12,796,000
Accumulated Depreciation	(4,215,000)
Year of Construction or Acquisition	1999
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	12,796,000
Deductions during year [Abstract]
Balance at close of year	4,215,000
Multi-Family Residential [Member] | Cypress Court - St. Cloud, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	1,136,000
Buildings & Improvements	12,428,000
Costs capitalized subsequent to acquisition	102,000
Gross amount at which carried at close of period [Abstract]
Land	1,136,000
Buildings & Improvements	12,530,000
Total	13,666,000
Accumulated Depreciation	(196,000)
Year of Construction or Acquisition	2012
Deductions during year [Abstract]
Balance at close of year	13,666,000
Deductions during year [Abstract]
Balance at close of year	196,000
Multi-Family Residential [Member] | Evergreen - Isanti, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	2,019,000
Initial Cost to Company [Abstract]
Land	380,000
Buildings & Improvements	2,740,000
Costs capitalized subsequent to acquisition	84,000
Gross amount at which carried at close of period [Abstract]
Land	380,000
Buildings & Improvements	2,824,000
Total	3,204,000
Accumulated Depreciation	(398,000)
Year of Construction or Acquisition	2008
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	3,204,000
Deductions during year [Abstract]
Balance at close of year	398,000
Multi-Family Residential [Member] | Evergreen II - Isanti, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	2,108,000
Initial Cost to Company [Abstract]
Land	691,000
Buildings & Improvements	2,784,000
Costs capitalized subsequent to acquisition	23,000
Gross amount at which carried at close of period [Abstract]
Land	691,000
Buildings & Improvements	2,807,000
Total	3,498,000
Accumulated Depreciation	(196,000)
Year of Construction or Acquisition	2011
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	3,498,000
Deductions during year [Abstract]
Balance at close of year	196,000
Multi-Family Residential [Member] | Fairmont - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	344,000
Initial Cost to Company [Abstract]
Land	28,000
Buildings & Improvements	337,000
Costs capitalized subsequent to acquisition	70,000
Gross amount at which carried at close of period [Abstract]
Land	55,000
Buildings & Improvements	380,000
Total	435,000
Accumulated Depreciation	(61,000)
Year of Construction or Acquisition	2008
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	435,000
Deductions during year [Abstract]
Balance at close of year	61,000
Multi-Family Residential [Member] | First Avenue - Minot ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	0
Buildings & Improvements	3,046,000
Costs capitalized subsequent to acquisition	5,000
Gross amount at which carried at close of period [Abstract]
Land	0
Buildings & Improvements	3,051,000
Total	3,051,000
Accumulated Depreciation	(78,000)
Year of Construction or Acquisition	2013
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	3,051,000
Deductions during year [Abstract]
Balance at close of year	78,000
Multi-Family Residential [Member] | Forest Park - Grand Forks, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	7,692,000
Initial Cost to Company [Abstract]
Land	810,000
Buildings & Improvements	5,579,000
Costs capitalized subsequent to acquisition	7,031,000
Gross amount at which carried at close of period [Abstract]
Land	1,409,000
Buildings & Improvements	12,011,000
Total	13,420,000
Accumulated Depreciation	(4,893,000)
Year of Construction or Acquisition	1993
Deductions during year [Abstract]
Balance at close of year	13,420,000
Deductions during year [Abstract]
Balance at close of year	4,893,000
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	20 years
Multi-Family Residential [Member] | Forest Park - Grand Forks, ND [Member] | Maximum [Member]
Gross amount at which carried at close of period [Abstract]
Life on which depreciation in latest income statement is computed	40 years
Multi-Family Residential [Member] | Gables Townhomes - Sioux Falls, SD [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	1,476,000
Initial Cost to Company [Abstract]
Land	349,000
Buildings & Improvements	1,921,000
Costs capitalized subsequent to acquisition	160,000
Gross amount at which carried at close of period [Abstract]
Land	371,000
Buildings & Improvements	2,059,000
Total	2,430,000
Accumulated Depreciation	(133,000)
Year of Construction or Acquisition	2011
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	2,430,000
Deductions during year [Abstract]
Balance at close of year	133,000
Multi-Family Residential [Member] | Grand Gateway - St. Cloud, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	5,465,000
Initial Cost to Company [Abstract]
Land	814,000
Buildings & Improvements	7,086,000
Costs capitalized subsequent to acquisition	580,000
Gross amount at which carried at close of period [Abstract]
Land	912,000
Buildings & Improvements	7,568,000
Total	8,480,000
Accumulated Depreciation	(490,000)
Year of Construction or Acquisition	2012
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	8,480,000
Deductions during year [Abstract]
Balance at close of year	490,000
Multi-Family Residential [Member] | Greenfield - Omaha, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	3,598,000
Initial Cost to Company [Abstract]
Land	578,000
Buildings & Improvements	4,122,000
Costs capitalized subsequent to acquisition	663,000
Gross amount at which carried at close of period [Abstract]
Land	778,000
Buildings & Improvements	4,585,000
Total	5,363,000
Accumulated Depreciation	(783,000)
Year of Construction or Acquisition	2007
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	5,363,000
Deductions during year [Abstract]
Balance at close of year	783,000
Multi-Family Residential [Member] | Heritage Manor - Rochester, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	4,051,000
Initial Cost to Company [Abstract]
Land	403,000
Buildings & Improvements	6,968,000
Costs capitalized subsequent to acquisition	2,632,000
Gross amount at which carried at close of period [Abstract]
Land	578,000
Buildings & Improvements	9,425,000
Total	10,003,000
Accumulated Depreciation	(3,489,000)
Year of Construction or Acquisition	1998
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	10,003,000
Deductions during year [Abstract]
Balance at close of year	3,489,000
Multi-Family Residential [Member] | Indian Hills - Sioux City, IA [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	294,000
Buildings & Improvements	2,921,000
Costs capitalized subsequent to acquisition	3,403,000
Gross amount at which carried at close of period [Abstract]
Land	386,000
Buildings & Improvements	6,232,000
Total	6,618,000
Accumulated Depreciation	(1,144,000)
Year of Construction or Acquisition	2007
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	6,618,000
Deductions during year [Abstract]
Balance at close of year	1,144,000
Multi-Family Residential [Member] | Kirkwood Manor - Bismarck, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	3,312,000
Initial Cost to Company [Abstract]
Land	449,000
Buildings & Improvements	2,725,000
Costs capitalized subsequent to acquisition	1,579,000
Gross amount at which carried at close of period [Abstract]
Land	546,000
Buildings & Improvements	4,207,000
Total	4,753,000
Accumulated Depreciation	(1,655,000)
Year of Construction or Acquisition	1997
Deductions during year [Abstract]
Balance at close of year	4,753,000
Deductions during year [Abstract]
Balance at close of year	1,655,000
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	13,382,000
Initial Cost to Company [Abstract]
Land	1,215,000
Buildings & Improvements	15,837,000
Costs capitalized subsequent to acquisition	262,000
Gross amount at which carried at close of period [Abstract]
Land	1,235,000
Buildings & Improvements	16,079,000
Total	17,314,000
Accumulated Depreciation	(821,000)
Year of Construction or Acquisition	2012
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	17,314,000
Deductions during year [Abstract]
Balance at close of year	821,000
Multi-Family Residential [Member] | Lancaster - St. Cloud, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	289,000
Buildings & Improvements	2,899,000
Costs capitalized subsequent to acquisition	1,079,000
Gross amount at which carried at close of period [Abstract]
Land	460,000
Buildings & Improvements	3,807,000
Total	4,267,000
Accumulated Depreciation	(1,410,000)
Year of Construction or Acquisition	2000
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	4,267,000
Deductions during year [Abstract]
Balance at close of year	1,410,000
Multi-Family Residential [Member] | Landing at Southgate - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	2,254,000
Buildings & Improvements	12,872,000
Costs capitalized subsequent to acquisition	25,000
Gross amount at which carried at close of period [Abstract]
Land	2,254,000
Buildings & Improvements	12,897,000
Total	15,151,000
Accumulated Depreciation	(212,000)
Year of Construction or Acquisition	2013
Deductions during year [Abstract]
Balance at close of year	15,151,000
Deductions during year [Abstract]
Balance at close of year	212,000
Multi-Family Residential [Member] | Landmark - Grand Forks, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	1,638,000
Initial Cost to Company [Abstract]
Land	184,000
Buildings & Improvements	1,514,000
Costs capitalized subsequent to acquisition	1,023,000
Gross amount at which carried at close of period [Abstract]
Land	313,000
Buildings & Improvements	2,408,000
Total	2,721,000
Accumulated Depreciation	(983,000)
Year of Construction or Acquisition	1997
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	2,721,000
Deductions during year [Abstract]
Balance at close of year	983,000
Multi-Family Residential [Member] | Legacy - Grand Forks, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	15,885,000
Initial Cost to Company [Abstract]
Land	1,362,000
Buildings & Improvements	21,727,000
Costs capitalized subsequent to acquisition	6,289,000
Gross amount at which carried at close of period [Abstract]
Land	2,088,000
Buildings & Improvements	27,290,000
Total	29,378,000
Accumulated Depreciation	(9,395,000)
Deductions during year [Abstract]
Balance at close of year	29,378,000
Deductions during year [Abstract]
Balance at close of year	9,395,000
Multi-Family Residential [Member] | Legacy - Grand Forks, ND [Member] | Minimum [Member]
Gross amount at which carried at close of period [Abstract]
Year 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]
Year of Construction or Acquisition	2005
Life on which depreciation in latest income statement is computed	40 years
Multi-Family Residential [Member] | Mariposa - Topeka, KS [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	2,975,000
Initial Cost to Company [Abstract]
Land	399,000
Buildings & Improvements	5,110,000
Costs capitalized subsequent to acquisition	487,000
Gross amount at which carried at close of period [Abstract]
Land	426,000
Buildings & Improvements	5,570,000
Total	5,996,000
Accumulated Depreciation	(1,341,000)
Year of Construction or Acquisition	2004
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	5,996,000
Deductions during year [Abstract]
Balance at close of year	1,341,000
Multi-Family Residential [Member] | Meadows - Jamestown, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	590,000
Buildings & Improvements	4,519,000
Costs capitalized subsequent to acquisition	1,256,000
Gross amount at which carried at close of period [Abstract]
Land	653,000
Buildings & Improvements	5,712,000
Total	6,365,000
Accumulated Depreciation	(1,968,000)
Year of Construction or Acquisition	1998
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	6,365,000
Deductions during year [Abstract]
Balance at close of year	1,968,000
Multi-Family Residential [Member] | Monticello Village - Monticello, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	490,000
Buildings & Improvements	3,756,000
Costs capitalized subsequent to acquisition	447,000
Gross amount at which carried at close of period [Abstract]
Land	621,000
Buildings & Improvements	4,072,000
Total	4,693,000
Accumulated Depreciation	(1,136,000)
Year of Construction or Acquisition	2004
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	4,693,000
Deductions during year [Abstract]
Balance at close of year	1,136,000
Multi-Family Residential [Member] | North Pointe - Bismarck, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	3,431,000
Initial Cost to Company [Abstract]
Land	303,000
Buildings & Improvements	3,957,000
Costs capitalized subsequent to acquisition	532,000
Gross amount at which carried at close of period [Abstract]
Land	339,000
Buildings & Improvements	4,453,000
Total	4,792,000
Accumulated Depreciation	(1,338,000)
Deductions during year [Abstract]
Balance at close of year	4,792,000
Deductions during year [Abstract]
Balance at close of year	1,338,000
Multi-Family Residential [Member] | North Pointe - Bismarck, ND [Member] | Minimum [Member]
Gross amount at which carried at close of period [Abstract]
Year 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]
Year of Construction or Acquisition	2011
Life on which depreciation in latest income statement is computed	40 years
Multi-Family Residential [Member] | Northern Valley - Rochester, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	110,000
Buildings & Improvements	610,000
Costs capitalized subsequent to acquisition	108,000
Gross amount at which carried at close of period [Abstract]
Land	119,000
Buildings & Improvements	709,000
Total	828,000
Accumulated Depreciation	(77,000)
Year of Construction or Acquisition	2010
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	828,000
Deductions during year [Abstract]
Balance at close of year	77,000
Multi-Family Residential [Member] | Oakmont Estates - Sioux Falls, SD [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	2,473,000
Initial Cost to Company [Abstract]
Land	423,000
Buildings & Improvements	4,838,000
Costs capitalized subsequent to acquisition	517,000
Gross amount at which carried at close of period [Abstract]
Land	558,000
Buildings & Improvements	5,220,000
Total	5,778,000
Accumulated Depreciation	(1,602,000)
Year of Construction or Acquisition	2002
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	5,778,000
Deductions during year [Abstract]
Balance at close of year	1,602,000
Multi-Family Residential [Member] | Oakwood Estates - Sioux Falls, SD [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	4,025,000
Initial Cost to Company [Abstract]
Land	543,000
Buildings & Improvements	2,784,000
Costs capitalized subsequent to acquisition	4,265,000
Gross amount at which carried at close of period [Abstract]
Land	775,000
Buildings & Improvements	6,817,000
Total	7,592,000
Accumulated Depreciation	(3,015,000)
Year of Construction or Acquisition	1993
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	7,592,000
Deductions during year [Abstract]
Balance at close of year	3,015,000
Multi-Family Residential [Member] | Olympic Village - Billings, MT [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	10,770,000
Initial Cost to Company [Abstract]
Land	1,164,000
Buildings & Improvements	10,441,000
Costs capitalized subsequent to acquisition	2,861,000
Gross amount at which carried at close of period [Abstract]
Land	1,757,000
Buildings & Improvements	12,709,000
Total	14,466,000
Accumulated Depreciation	(4,461,000)
Year of Construction or Acquisition	2000
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	14,466,000
Deductions during year [Abstract]
Balance at close of year	4,461,000
Multi-Family Residential [Member] | Olympik Village - Rochester, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	4,499,000
Initial Cost to Company [Abstract]
Land	1,034,000
Buildings & Improvements	6,109,000
Costs capitalized subsequent to acquisition	1,711,000
Gross amount at which carried at close of period [Abstract]
Land	1,168,000
Buildings & Improvements	7,686,000
Total	8,854,000
Accumulated Depreciation	(1,870,000)
Year of Construction or Acquisition	2005
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	8,854,000
Deductions during year [Abstract]
Balance at close of year	1,870,000
Multi-Family Residential [Member] | Oxbow Park - Sioux Falls, SD [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	3,931,000
Initial Cost to Company [Abstract]
Land	404,000
Buildings & Improvements	3,152,000
Costs capitalized subsequent to acquisition	2,658,000
Gross amount at which carried at close of period [Abstract]
Land	665,000
Buildings & Improvements	5,549,000
Total	6,214,000
Accumulated Depreciation	(2,625,000)
Year of Construction or Acquisition	1994
Deductions during year [Abstract]
Balance at close of year	6,214,000
Deductions during year [Abstract]
Balance at close of year	2,625,000
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	8,616,000
Initial Cost to Company [Abstract]
Land	1,143,000
Buildings & Improvements	9,099,000
Costs capitalized subsequent to acquisition	5,423,000
Gross amount at which carried at close of period [Abstract]
Land	1,595,000
Buildings & Improvements	14,070,000
Total	15,665,000
Accumulated Depreciation	(5,790,000)
Year of Construction or Acquisition	1997
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	15,665,000
Deductions during year [Abstract]
Balance at close of year	5,790,000
Multi-Family Residential [Member] | Pebble Springs - Bismarck, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	775,000
Initial Cost to Company [Abstract]
Land	7,000
Buildings & Improvements	748,000
Costs capitalized subsequent to acquisition	149,000
Gross amount at which carried at close of period [Abstract]
Land	44,000
Buildings & Improvements	860,000
Total	904,000
Accumulated Depreciation	(323,000)
Year of Construction or Acquisition	1999
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	904,000
Deductions during year [Abstract]
Balance at close of year	323,000
Multi-Family Residential [Member] | Pinehurst - Billings, MT [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	243,000
Initial Cost to Company [Abstract]
Land	72,000
Buildings & Improvements	687,000
Costs capitalized subsequent to acquisition	239,000
Gross amount at which carried at close of period [Abstract]
Land	79,000
Buildings & Improvements	919,000
Total	998,000
Accumulated Depreciation	(276,000)
Year of Construction or Acquisition	2002
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	998,000
Deductions during year [Abstract]
Balance at close of year	276,000
Multi-Family Residential [Member] | Pinecone Villas - Sartell, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	584,000
Buildings & Improvements	2,191,000
Costs capitalized subsequent to acquisition	8,000
Gross amount at which carried at close of period [Abstract]
Land	584,000
Buildings & Improvements	2,199,000
Total	2,783,000
Accumulated Depreciation	(33,000)
Deductions during year [Abstract]
Balance at close of year	2,783,000
Deductions during year [Abstract]
Balance at close of year	33,000
Multi-Family Residential [Member] | Pines - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	120,000
Initial Cost to Company [Abstract]
Land	35,000
Buildings & Improvements	215,000
Costs capitalized subsequent to acquisition	184,000
Gross amount at which carried at close of period [Abstract]
Land	49,000
Buildings & Improvements	385,000
Total	434,000
Accumulated Depreciation	(132,000)
Year of Construction or Acquisition	1997
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	434,000
Deductions during year [Abstract]
Balance at close of year	132,000
Multi-Family Residential [Member] | Plaza - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	5,478,000
Initial Cost to Company [Abstract]
Land	867,000
Buildings & Improvements	12,784,000
Costs capitalized subsequent to acquisition	2,335,000
Gross amount at which carried at close of period [Abstract]
Land	992,000
Buildings & Improvements	14,994,000
Total	15,986,000
Accumulated Depreciation	(2,029,000)
Year of Construction or Acquisition	2009
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	15,986,000
Deductions during year [Abstract]
Balance at close of year	2,029,000
Multi-Family Residential [Member] | Pointe West - Rapid City, SD [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	2,679,000
Initial Cost to Company [Abstract]
Land	240,000
Buildings & Improvements	3,538,000
Costs capitalized subsequent to acquisition	1,485,000
Gross amount at which carried at close of period [Abstract]
Land	364,000
Buildings & Improvements	4,899,000
Total	5,263,000
Accumulated Depreciation	(2,240,000)
Year of Construction or Acquisition	1994
Deductions during year [Abstract]
Balance at close of year	5,263,000
Deductions during year [Abstract]
Balance at close of year	2,240,000
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	3,950,000
Initial Cost to Company [Abstract]
Land	395,000
Buildings & Improvements	4,564,000
Costs capitalized subsequent to acquisition	232,000
Gross amount at which carried at close of period [Abstract]
Land	395,000
Buildings & Improvements	4,796,000
Total	5,191,000
Accumulated Depreciation	(216,000)
Year of Construction or Acquisition	2012
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	5,191,000
Deductions during year [Abstract]
Balance at close of year	216,000
Multi-Family Residential [Member] | Prairie Winds - Sioux Falls, SD [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	1,438,000
Initial Cost to Company [Abstract]
Land	144,000
Buildings & Improvements	1,816,000
Costs capitalized subsequent to acquisition	466,000
Gross amount at which carried at close of period [Abstract]
Land	229,000
Buildings & Improvements	2,197,000
Total	2,426,000
Accumulated Depreciation	(1,171,000)
Year of Construction or Acquisition	1993
Deductions during year [Abstract]
Balance at close of year	2,426,000
Deductions during year [Abstract]
Balance at close of year	1,171,000
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	13,603,000
Initial Cost to Company [Abstract]
Land	1,312,000
Buildings & Improvements	13,362,000
Costs capitalized subsequent to acquisition	1,129,000
Gross amount at which carried at close of period [Abstract]
Land	1,353,000
Buildings & Improvements	14,450,000
Total	15,803,000
Accumulated Depreciation	(2,811,000)
Year of Construction or Acquisition	2006
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	15,803,000
Deductions during year [Abstract]
Balance at close of year	2,811,000
Multi-Family Residential [Member] | Quarry Ridge 2 - Rochester, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	14,158,000
Initial Cost to Company [Abstract]
Land	942,000
Buildings & Improvements	16,661,000
Costs capitalized subsequent to acquisition	39,000
Gross amount at which carried at close of period [Abstract]
Land	945,000
Buildings & Improvements	16,697,000
Total	17,642,000
Accumulated Depreciation	(830,000)
Year of Construction or Acquisition	2012
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	17,642,000
Deductions during year [Abstract]
Balance at close of year	830,000
Multi-Family Residential [Member] | Regency Park Estates - St. Cloud, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	6,827,000
Initial Cost to Company [Abstract]
Land	702,000
Buildings & Improvements	10,198,000
Costs capitalized subsequent to acquisition	1,244,000
Gross amount at which carried at close of period [Abstract]
Land	751,000
Buildings & Improvements	11,393,000
Total	12,144,000
Accumulated Depreciation	(804,000)
Year of Construction or Acquisition	2011
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	12,144,000
Deductions during year [Abstract]
Balance at close of year	804,000
Multi-Family Residential [Member] | Renaissance Heights I - Williston ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	616,000
Buildings & Improvements	10,872,000
Costs capitalized subsequent to acquisition	25,000
Gross amount at which carried at close of period [Abstract]
Land	616,000
Buildings & Improvements	10,897,000
Total	11,513,000
Accumulated Depreciation	(58,000)
Year of Construction or Acquisition	2013
Deductions during year [Abstract]
Balance at close of year	11,513,000
Deductions during year [Abstract]
Balance at close of year	58,000
Multi-Family Residential [Member] | Ridge Oaks - Sioux City, IA [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	3,414,000
Initial Cost to Company [Abstract]
Land	178,000
Buildings & Improvements	4,073,000
Costs capitalized subsequent to acquisition	2,087,000
Gross amount at which carried at close of period [Abstract]
Land	281,000
Buildings & Improvements	6,057,000
Total	6,338,000
Accumulated Depreciation	(2,042,000)
Year of Construction or Acquisition	2001
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	6,338,000
Deductions during year [Abstract]
Balance at close of year	2,042,000
Multi-Family Residential [Member] | Rimrock West - Billings, MT [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	3,339,000
Initial Cost to Company [Abstract]
Land	330,000
Buildings & Improvements	3,489,000
Costs capitalized subsequent to acquisition	1,453,000
Gross amount at which carried at close of period [Abstract]
Land	431,000
Buildings & Improvements	4,841,000
Total	5,272,000
Accumulated Depreciation	(1,624,000)
Year of Construction or Acquisition	1999
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	5,272,000
Deductions during year [Abstract]
Balance at close of year	1,624,000
Multi-Family Residential [Member] | River Ridge - Bismarck, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	576,000
Buildings & Improvements	23,434,000
Costs capitalized subsequent to acquisition	1,076,000
Gross amount at which carried at close of period [Abstract]
Land	1,423,000
Buildings & Improvements	23,663,000
Total	25,086,000
Accumulated Depreciation	(438,000)
Year of Construction or Acquisition	2008
Deductions during year [Abstract]
Balance at close of year	25,086,000
Deductions during year [Abstract]
Balance at close of year	438,000
Multi-Family Residential [Member] | Rocky Meadows - Billings, MT [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	5,177,000
Initial Cost to Company [Abstract]
Land	656,000
Buildings & Improvements	5,726,000
Costs capitalized subsequent to acquisition	1,085,000
Gross amount at which carried at close of period [Abstract]
Land	769,000
Buildings & Improvements	6,698,000
Total	7,467,000
Accumulated Depreciation	(2,942,000)
Year of Construction or Acquisition	1995
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	7,467,000
Deductions during year [Abstract]
Balance at close of year	2,942,000
Multi-Family Residential [Member] | Rum River - Isanti, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	3,609,000
Initial Cost to Company [Abstract]
Land	843,000
Buildings & Improvements	4,823,000
Costs capitalized subsequent to acquisition	146,000
Gross amount at which carried at close of period [Abstract]
Land	848,000
Buildings & Improvements	4,964,000
Total	5,812,000
Accumulated Depreciation	(882,000)
Year of Construction or Acquisition	2007
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	5,812,000
Deductions during year [Abstract]
Balance at close of year	882,000
Multi-Family Residential [Member] | Sherwood - Topeka, KS [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	12,340,000
Initial Cost to Company [Abstract]
Land	1,142,000
Buildings & Improvements	14,684,000
Costs capitalized subsequent to acquisition	2,870,000
Gross amount at which carried at close of period [Abstract]
Land	1,636,000
Buildings & Improvements	17,060,000
Total	18,696,000
Accumulated Depreciation	(6,150,000)
Year of Construction or Acquisition	1999
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	18,696,000
Deductions during year [Abstract]
Balance at close of year	6,150,000
Multi-Family Residential [Member] | Sierra Vista - Sioux Falls, SD [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	1,421,000
Initial Cost to Company [Abstract]
Land	241,000
Buildings & Improvements	2,097,000
Costs capitalized subsequent to acquisition	385,000
Gross amount at which carried at close of period [Abstract]
Land	265,000
Buildings & Improvements	2,458,000
Total	2,723,000
Accumulated Depreciation	(198,000)
Year of Construction or Acquisition	2011
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	2,723,000
Deductions during year [Abstract]
Balance at close of year	198,000
Multi-Family Residential [Member] | Southpoint - Grand Forks, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	576,000
Buildings & Improvements	9,893,000
Costs capitalized subsequent to acquisition	16,000
Gross amount at which carried at close of period [Abstract]
Land	576,000
Buildings & Improvements	9,909,000
Total	10,485,000
Accumulated Depreciation	(158,000)
Deductions during year [Abstract]
Balance at close of year	10,485,000
Deductions during year [Abstract]
Balance at close of year	158,000
Multi-Family Residential [Member] | South Pointe - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	8,789,000
Initial Cost to Company [Abstract]
Land	550,000
Buildings & Improvements	9,548,000
Costs capitalized subsequent to acquisition	2,603,000
Gross amount at which carried at close of period [Abstract]
Land	1,316,000
Buildings & Improvements	11,385,000
Total	12,701,000
Accumulated Depreciation	(5,165,000)
Year of Construction or Acquisition	1995
Deductions during year [Abstract]
Balance at close of year	12,701,000
Deductions during year [Abstract]
Balance at close of year	5,165,000
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] | Southview - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	1,059,000
Initial Cost to Company [Abstract]
Land	185,000
Buildings & Improvements	469,000
Costs capitalized subsequent to acquisition	355,000
Gross amount at which carried at close of period [Abstract]
Land	237,000
Buildings & Improvements	772,000
Total	1,009,000
Accumulated Depreciation	(344,000)
Year of Construction or Acquisition	1994
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	1,009,000
Deductions during year [Abstract]
Balance at close of year	344,000
Multi-Family Residential [Member] | Southwind - Grand Forks, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	5,615,000
Initial Cost to Company [Abstract]
Land	400,000
Buildings & Improvements	5,034,000
Costs capitalized subsequent to acquisition	2,714,000
Gross amount at which carried at close of period [Abstract]
Land	726,000
Buildings & Improvements	7,422,000
Total	8,148,000
Accumulated Depreciation	(3,216,000)
Year of Construction or Acquisition	1995
Deductions during year [Abstract]
Balance at close of year	8,148,000
Deductions during year [Abstract]
Balance at close of year	3,216,000
Multi-Family Residential [Member] | Southwind - Grand Forks, ND [Member] | Minimum [Member]
Gross amount at which carried at close of period [Abstract]
Life on which depreciation in latest income statement is computed	24 years
Multi-Family Residential [Member] | Southwind - Grand Forks, ND [Member] | Maximum [Member]
Gross amount at which carried at close of period [Abstract]
Life on which depreciation in latest income statement is computed	40 years
Multi-Family Residential [Member] | Summit Park - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	1,039,000
Initial Cost to Company [Abstract]
Land	161,000
Buildings & Improvements	1,898,000
Costs capitalized subsequent to acquisition	1,338,000
Gross amount at which carried at close of period [Abstract]
Land	419,000
Buildings & Improvements	2,978,000
Total	3,397,000
Accumulated Depreciation	(1,167,000)
Year of Construction or Acquisition	1997
Deductions during year [Abstract]
Balance at close of year	3,397,000
Deductions during year [Abstract]
Balance at close of year	1,167,000
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	8,138,000
Initial Cost to Company [Abstract]
Land	336,000
Buildings & Improvements	12,814,000
Costs capitalized subsequent to acquisition	2,490,000
Gross amount at which carried at close of period [Abstract]
Land	543,000
Buildings & Improvements	15,097,000
Total	15,640,000
Accumulated Depreciation	(5,011,000)
Year of Construction or Acquisition	1999
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	15,640,000
Deductions during year [Abstract]
Balance at close of year	5,011,000
Multi-Family Residential [Member] | Temple - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	78,000
Initial Cost to Company [Abstract]
Land	0
Buildings & Improvements	0
Costs capitalized subsequent to acquisition	229,000
Gross amount at which carried at close of period [Abstract]
Land	0
Buildings & Improvements	229,000
Total	229,000
Accumulated Depreciation	(50,000)
Year of Construction or Acquisition	2006
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	229,000
Deductions during year [Abstract]
Balance at close of year	50,000
Multi-Family Residential [Member] | Terrace Heights - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	173,000
Initial Cost to Company [Abstract]
Land	29,000
Buildings & Improvements	312,000
Costs capitalized subsequent to acquisition	88,000
Gross amount at which carried at close of period [Abstract]
Land	40,000
Buildings & Improvements	389,000
Total	429,000
Accumulated Depreciation	(164,000)
Year of Construction or Acquisition	2006
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	429,000
Deductions during year [Abstract]
Balance at close of year	164,000
Multi-Family Residential [Member] | Thomasbrook - Lincoln, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	5,987,000
Initial Cost to Company [Abstract]
Land	600,000
Buildings & Improvements	10,306,000
Costs capitalized subsequent to acquisition	3,189,000
Gross amount at which carried at close of period [Abstract]
Land	1,242,000
Buildings & Improvements	12,853,000
Total	14,095,000
Accumulated Depreciation	(4,366,000)
Year of Construction or Acquisition	1999
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	14,095,000
Deductions during year [Abstract]
Balance at close of year	4,366,000
Multi-Family Residential [Member] | University Park Place - St. Cloud, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	78,000
Buildings & Improvements	450,000
Costs capitalized subsequent to acquisition	100,000
Gross amount at which carried at close of period [Abstract]
Land	82,000
Buildings & Improvements	546,000
Total	628,000
Accumulated Depreciation	(99,000)
Year of Construction or Acquisition	2007
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	628,000
Deductions during year [Abstract]
Balance at close of year	99,000
Multi-Family Residential [Member] | Valley Park - Grand Forks, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	3,886,000
Initial Cost to Company [Abstract]
Land	294,000
Buildings & Improvements	4,137,000
Costs capitalized subsequent to acquisition	3,304,000
Gross amount at which carried at close of period [Abstract]
Land	1,095,000
Buildings & Improvements	6,640,000
Total	7,735,000
Accumulated Depreciation	(2,375,000)
Year of Construction or Acquisition	1999
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	7,735,000
Deductions during year [Abstract]
Balance at close of year	2,375,000
Multi-Family Residential [Member] | Villa West - Topeka, KS [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	12,280,000
Initial Cost to Company [Abstract]
Land	1,590,000
Buildings & Improvements	15,760,000
Costs capitalized subsequent to acquisition	513,000
Gross amount at which carried at close of period [Abstract]
Land	1,674,000
Buildings & Improvements	16,189,000
Total	17,863,000
Accumulated Depreciation	(845,000)
Year of Construction or Acquisition	2012
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	17,863,000
Deductions during year [Abstract]
Balance at close of year	845,000
Multi-Family Residential [Member] | Village Green - Rochester, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	1,145,000
Initial Cost to Company [Abstract]
Land	234,000
Buildings & Improvements	2,296,000
Costs capitalized subsequent to acquisition	800,000
Gross amount at which carried at close of period [Abstract]
Land	359,000
Buildings & Improvements	2,971,000
Total	3,330,000
Accumulated Depreciation	(828,000)
Year of Construction or Acquisition	2003
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	3,330,000
Deductions during year [Abstract]
Balance at close of year	828,000
Multi-Family Residential [Member] | West Stonehill - Waite Park, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	8,621,000
Initial Cost to Company [Abstract]
Land	939,000
Buildings & Improvements	10,167,000
Costs capitalized subsequent to acquisition	4,817,000
Gross amount at which carried at close of period [Abstract]
Land	1,473,000
Buildings & Improvements	14,450,000
Total	15,923,000
Accumulated Depreciation	(6,513,000)
Year of Construction or Acquisition	1995
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	15,923,000
Deductions during year [Abstract]
Balance at close of year	6,513,000
Multi-Family Residential [Member] | Westridge - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	1,662,000
Initial Cost to Company [Abstract]
Land	68,000
Buildings & Improvements	1,887,000
Costs capitalized subsequent to acquisition	165,000
Gross amount at which carried at close of period [Abstract]
Land	75,000
Buildings & Improvements	2,045,000
Total	2,120,000
Accumulated Depreciation	(309,000)
Year of Construction or Acquisition	2008
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	2,120,000
Deductions during year [Abstract]
Balance at close of year	309,000
Multi-Family Residential [Member] | Westwood Park - Bismarck, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	1,982,000
Initial Cost to Company [Abstract]
Land	116,000
Buildings & Improvements	1,909,000
Costs capitalized subsequent to acquisition	1,706,000
Gross amount at which carried at close of period [Abstract]
Land	268,000
Buildings & Improvements	3,463,000
Total	3,731,000
Accumulated Depreciation	(1,315,000)
Year of Construction or Acquisition	1998
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	3,731,000
Deductions during year [Abstract]
Balance at close of year	1,315,000
Multi-Family Residential [Member] | Whispering Ridge - Omaha, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	22,000,000
Initial Cost to Company [Abstract]
Land	2,139,000
Buildings & Improvements	25,424,000
Costs capitalized subsequent to acquisition	396,000
Gross amount at which carried at close of period [Abstract]
Land	2,243,000
Buildings & Improvements	25,716,000
Total	27,959,000
Accumulated Depreciation	(806,000)
Year of Construction or Acquisition	2012
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	27,959,000
Deductions during year [Abstract]
Balance at close of year	806,000
Multi-Family Residential [Member] | Williston Garden - Williston, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	12,057,000
Initial Cost to Company [Abstract]
Land	1,400,000
Buildings & Improvements	17,699,000
Costs capitalized subsequent to acquisition	33,000
Gross amount at which carried at close of period [Abstract]
Land	1,408,000
Buildings & Improvements	17,724,000
Total	19,132,000
Accumulated Depreciation	(1,416,000)
Year of Construction or Acquisition	2012
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	19,132,000
Deductions during year [Abstract]
Balance at close of year	1,416,000
Multi-Family Residential [Member] | Winchester - Rochester, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	2,802,000
Initial Cost to Company [Abstract]
Land	748,000
Buildings & Improvements	5,622,000
Costs capitalized subsequent to acquisition	1,700,000
Gross amount at which carried at close of period [Abstract]
Land	1,006,000
Buildings & Improvements	7,064,000
Total	8,070,000
Accumulated Depreciation	(2,071,000)
Year of Construction or Acquisition	2003
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	8,070,000
Deductions during year [Abstract]
Balance at close of year	2,071,000
Multi-Family Residential [Member] | Woodridge - Rochester, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	6,412,000
Initial Cost to Company [Abstract]
Land	370,000
Buildings & Improvements	6,028,000
Costs capitalized subsequent to acquisition	1,925,000
Gross amount at which carried at close of period [Abstract]
Land	502,000
Buildings & Improvements	7,821,000
Total	8,323,000
Accumulated Depreciation	(3,337,000)
Year of Construction or Acquisition	1997
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	8,323,000
Deductions during year [Abstract]
Balance at close of year	3,337,000
Multi-Family Residential [Member] | Wholly Owned Properties [Member]
Additions during year [Abstract]
Additions	84,117,000		113,859,000		47,433,000
Commercial-Office [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	328,879,000
Initial Cost to Company [Abstract]
Land	70,098,000
Buildings & Improvements	407,590,000
Costs capitalized subsequent to acquisition	66,940,000
Gross amount at which carried at close of period [Abstract]
Land	72,277,000
Buildings & Improvements	472,351,000
Total	544,628,000
Accumulated Depreciation	(121,892,000)
Deductions during year [Abstract]
Balance at close of year	544,628,000
Deductions during year [Abstract]
Balance at close of year	121,892,000
Commercial-Office [Member] | Eden Prairie 6101 Blue Circle Drive - Eden Prairie, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	666,000
Buildings & Improvements	4,197,000
Costs capitalized subsequent to acquisition	1,000
Gross amount at which carried at close of period [Abstract]
Land	666,000
Buildings & Improvements	4,198,000
Total	4,864,000
Accumulated Depreciation	(1,596,000)
Year of Construction or Acquisition	1999
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	4,864,000
Deductions during year [Abstract]
Balance at close of year	1,596,000
Commercial-Office [Member] | Granite Corporate Center - St. Cloud, MN [Member]
Gross amount at which carried at close of period [Abstract]
Total	9,764,000
Deductions during year [Abstract]
Balance at close of year	9,764,000
Commercial-Office [Member] | 1st Avenue Building - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	30,000
Buildings & Improvements	0
Costs capitalized subsequent to acquisition	337,000
Gross amount at which carried at close of period [Abstract]
Land	30,000
Buildings & Improvements	337,000
Total	367,000
Accumulated Depreciation	(33,000)
Year of Construction or Acquisition	1981
Deductions during year [Abstract]
Balance at close of year	367,000
Deductions during year [Abstract]
Balance at close of year	33,000
Commercial-Office [Member] | 1st Avenue Building - Minot, ND [Member] | Minimum [Member]
Gross amount at which carried at close of period [Abstract]
Life on which depreciation in latest income statement is computed	33 years
Commercial-Office [Member] | 1st Avenue Building - Minot, ND [Member] | Maximum [Member]
Gross amount at which carried at close of period [Abstract]
Life on which depreciation in latest income statement is computed	40 years
Commercial-Office [Member] | 2030 Cliff Road - Eagan, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	938,000
Initial Cost to Company [Abstract]
Land	146,000
Buildings & Improvements	835,000
Costs capitalized subsequent to acquisition	90,000
Gross amount at which carried at close of period [Abstract]
Land	158,000
Buildings & Improvements	913,000
Total	1,071,000
Accumulated Depreciation	(300,000)
Year of Construction or Acquisition	2001
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	1,071,000
Deductions during year [Abstract]
Balance at close of year	300,000
Commercial-Office [Member] | 610 Business Center IV - Brooklyn Park, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	6,888,000
Initial Cost to Company [Abstract]
Land	975,000
Buildings & Improvements	5,542,000
Costs capitalized subsequent to acquisition	2,886,000
Gross amount at which carried at close of period [Abstract]
Land	980,000
Buildings & Improvements	8,423,000
Total	9,403,000
Accumulated Depreciation	(2,060,000)
Year of Construction or Acquisition	2007
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	9,403,000
Deductions during year [Abstract]
Balance at close of year	2,060,000
Commercial-Office [Member] | 7800 West Brown Deer Road - Milwaukee, WI [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	10,520,000
Initial Cost to Company [Abstract]
Land	1,455,000
Buildings & Improvements	8,756,000
Costs capitalized subsequent to acquisition	2,333,000
Gross amount at which carried at close of period [Abstract]
Land	1,475,000
Buildings & Improvements	11,069,000
Total	12,544,000
Accumulated Depreciation	(3,621,000)
Year of Construction or Acquisition	2003
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	12,544,000
Deductions during year [Abstract]
Balance at close of year	3,621,000
Commercial-Office [Member] | American Corporate Center - Mendota Heights, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	8,794,000
Initial Cost to Company [Abstract]
Land	893,000
Buildings & Improvements	16,768,000
Costs capitalized subsequent to acquisition	4,062,000
Gross amount at which carried at close of period [Abstract]
Land	893,000
Buildings & Improvements	20,830,000
Total	21,723,000
Accumulated Depreciation	(8,339,000)
Year of Construction or Acquisition	2002
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	21,723,000
Deductions during year [Abstract]
Balance at close of year	8,339,000
Commercial-Office [Member] | Ameritrade - Omaha, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	2,440,000
Initial Cost to Company [Abstract]
Land	327,000
Buildings & Improvements	7,957,000
Costs capitalized subsequent to acquisition	65,000
Gross amount at which carried at close of period [Abstract]
Land	327,000
Buildings & Improvements	8,022,000
Total	8,349,000
Accumulated Depreciation	(3,014,000)
Year of Construction or Acquisition	1999
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	8,349,000
Deductions during year [Abstract]
Balance at close of year	3,014,000
Commercial-Office [Member] | Benton Business Park - Sauk Rapids, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	491,000
Initial Cost to Company [Abstract]
Land	188,000
Buildings & Improvements	1,261,000
Costs capitalized subsequent to acquisition	89,000
Gross amount at which carried at close of period [Abstract]
Land	188,000
Buildings & Improvements	1,350,000
Total	1,538,000
Accumulated Depreciation	(394,000)
Year of Construction or Acquisition	2003
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	1,538,000
Deductions during year [Abstract]
Balance at close of year	394,000
Commercial-Office [Member] | Bismarck 715 East Broadway - Bismarck, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	2,163,000
Initial Cost to Company [Abstract]
Land	389,000
Buildings & Improvements	1,283,000
Costs capitalized subsequent to acquisition	1,126,000
Gross amount at which carried at close of period [Abstract]
Land	443,000
Buildings & Improvements	2,355,000
Total	2,798,000
Accumulated Depreciation	(373,000)
Year of Construction or Acquisition	2008
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	2,798,000
Deductions during year [Abstract]
Balance at close of year	373,000
Commercial-Office [Member] | Brenwood - Minnetonka, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	1,642,000
Buildings & Improvements	12,138,000
Costs capitalized subsequent to acquisition	3,203,000
Gross amount at which carried at close of period [Abstract]
Land	1,650,000
Buildings & Improvements	15,333,000
Total	16,983,000
Accumulated Depreciation	(5,379,000)
Year of Construction or Acquisition	2002
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	16,983,000
Deductions during year [Abstract]
Balance at close of year	5,379,000
Commercial-Office [Member] | Brook Valley I - La Vista, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	1,256,000
Initial Cost to Company [Abstract]
Land	347,000
Buildings & Improvements	1,671,000
Costs capitalized subsequent to acquisition	129,000
Gross amount at which carried at close of period [Abstract]
Land	347,000
Buildings & Improvements	1,800,000
Total	2,147,000
Accumulated Depreciation	(407,000)
Year of Construction or Acquisition	2005
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	2,147,000
Deductions during year [Abstract]
Balance at close of year	407,000
Commercial-Office [Member] | Burnsville Bluffs II - Burnsville, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	1,679,000
Initial Cost to Company [Abstract]
Land	300,000
Buildings & Improvements	2,154,000
Costs capitalized subsequent to acquisition	986,000
Gross amount at which carried at close of period [Abstract]
Land	374,000
Buildings & Improvements	3,066,000
Total	3,440,000
Accumulated Depreciation	(1,324,000)
Year of Construction or Acquisition	2001
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	3,440,000
Deductions during year [Abstract]
Balance at close of year	1,324,000
Commercial-Office [Member] | Corporate Center West - Omaha, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	17,315,000
Initial Cost to Company [Abstract]
Land	3,880,000
Buildings & Improvements	5,253,000
Costs capitalized subsequent to acquisition	0
Gross amount at which carried at close of period [Abstract]
Land	3,880,000
Buildings & Improvements	5,253,000
Total	9,133,000
Accumulated Depreciation	0
Year of Construction or Acquisition	2006
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	9,133,000
Deductions during year [Abstract]
Balance at close of year	0
Commercial-Office [Member] | Crosstown Centre - Eden Prairie, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	12,707,000
Initial Cost to Company [Abstract]
Land	2,884,000
Buildings & Improvements	14,569,000
Costs capitalized subsequent to acquisition	2,563,000
Gross amount at which carried at close of period [Abstract]
Land	2,932,000
Buildings & Improvements	17,084,000
Total	20,016,000
Accumulated Depreciation	(4,328,000)
Year of Construction or Acquisition	2004
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	20,016,000
Deductions during year [Abstract]
Balance at close of year	4,328,000
Commercial-Office [Member] | Farnam Executive Center - Omaha, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	12,160,000
Initial Cost to Company [Abstract]
Land	2,188,000
Buildings & Improvements	7,912,000
Costs capitalized subsequent to acquisition	0
Gross amount at which carried at close of period [Abstract]
Land	2,188,000
Buildings & Improvements	7,912,000
Total	10,100,000
Accumulated Depreciation	0
Year of Construction or Acquisition	2006
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	10,100,000
Deductions during year [Abstract]
Balance at close of year	0
Commercial-Office [Member] | Flagship - Eden Prairie, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	21,565,000
Initial Cost to Company [Abstract]
Land	1,899,000
Buildings & Improvements	15,518,000
Costs capitalized subsequent to acquisition	0
Gross amount at which carried at close of period [Abstract]
Land	1,899,000
Buildings & Improvements	15,518,000
Total	17,417,000
Accumulated Depreciation	0
Year of Construction or Acquisition	2006
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	17,417,000
Deductions during year [Abstract]
Balance at close of year	0
Commercial-Office [Member] | Gateway Corporate Center - Woodbury, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	8,700,000
Initial Cost to Company [Abstract]
Land	1,637,000
Buildings & Improvements	6,663,000
Costs capitalized subsequent to acquisition	0
Gross amount at which carried at close of period [Abstract]
Land	1,637,000
Buildings & Improvements	6,663,000
Total	8,300,000
Accumulated Depreciation	0
Year of Construction or Acquisition	2006
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	8,300,000
Deductions during year [Abstract]
Balance at close of year	0
Commercial-Office [Member] | Golden Hills Office Center - Golden Valley, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	17,711,000
Initial Cost to Company [Abstract]
Land	3,018,000
Buildings & Improvements	18,544,000
Costs capitalized subsequent to acquisition	3,852,000
Gross amount at which carried at close of period [Abstract]
Land	3,018,000
Buildings & Improvements	22,396,000
Total	25,414,000
Accumulated Depreciation	(8,049,000)
Year of Construction or Acquisition	2003
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	25,414,000
Deductions during year [Abstract]
Balance at close of year	8,049,000
Commercial-Office [Member] | Great Plains - Fargo, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	126,000
Buildings & Improvements	15,240,000
Costs capitalized subsequent to acquisition	719,000
Gross amount at which carried at close of period [Abstract]
Land	126,000
Buildings & Improvements	15,959,000
Total	16,085,000
Accumulated Depreciation	(5,640,000)
Year of Construction or Acquisition	1997
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	16,085,000
Deductions during year [Abstract]
Balance at close of year	5,640,000
Commercial-Office [Member] | Highlands Ranch I - Highlands Ranch, CO [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	7,992,000
Initial Cost to Company [Abstract]
Land	2,268,000
Buildings & Improvements	8,362,000
Costs capitalized subsequent to acquisition	427,000
Gross amount at which carried at close of period [Abstract]
Land	2,268,000
Buildings & Improvements	8,789,000
Total	11,057,000
Accumulated Depreciation	(1,829,000)
Year of Construction or Acquisition	2006
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	11,057,000
Deductions during year [Abstract]
Balance at close of year	1,829,000
Commercial-Office [Member] | Highlands Ranch II - Highlands Ranch, CO [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	7,601,000
Initial Cost to Company [Abstract]
Land	1,437,000
Buildings & Improvements	9,549,000
Costs capitalized subsequent to acquisition	1,693,000
Gross amount at which carried at close of period [Abstract]
Land	1,437,000
Buildings & Improvements	11,242,000
Total	12,679,000
Accumulated Depreciation	(3,011,000)
Year of Construction or Acquisition	2004
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	12,679,000
Deductions during year [Abstract]
Balance at close of year	3,011,000
Commercial-Office [Member] | Interlachen Corporate Center - Edina, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	8,619,000
Initial Cost to Company [Abstract]
Land	1,650,000
Buildings & Improvements	14,983,000
Costs capitalized subsequent to acquisition	2,459,000
Gross amount at which carried at close of period [Abstract]
Land	1,668,000
Buildings & Improvements	17,424,000
Total	19,092,000
Accumulated Depreciation	(5,684,000)
Year of Construction or Acquisition	2001
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	19,092,000
Deductions during year [Abstract]
Balance at close of year	5,684,000
Commercial-Office [Member] | Intertech Building - Fenton, MO [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	4,301,000
Initial Cost to Company [Abstract]
Land	2,130,000
Buildings & Improvements	3,968,000
Costs capitalized subsequent to acquisition	1,268,000
Gross amount at which carried at close of period [Abstract]
Land	2,191,000
Buildings & Improvements	5,175,000
Total	7,366,000
Accumulated Depreciation	(970,000)
Year of Construction or Acquisition	2007
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	7,366,000
Deductions during year [Abstract]
Balance at close of year	970,000
Commercial-Office [Member] | Mendota Office Center I - Mendota Heights, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	3,787,000
Initial Cost to Company [Abstract]
Land	835,000
Buildings & Improvements	6,169,000
Costs capitalized subsequent to acquisition	889,000
Gross amount at which carried at close of period [Abstract]
Land	835,000
Buildings & Improvements	7,058,000
Total	7,893,000
Accumulated Depreciation	(2,420,000)
Year of Construction or Acquisition	2002
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	7,893,000
Deductions during year [Abstract]
Balance at close of year	2,420,000
Commercial-Office [Member] | Mendota Office Center II - Mendota Heights, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	5,595,000
Initial Cost to Company [Abstract]
Land	1,121,000
Buildings & Improvements	10,085,000
Costs capitalized subsequent to acquisition	1,712,000
Gross amount at which carried at close of period [Abstract]
Land	1,121,000
Buildings & Improvements	11,797,000
Total	12,918,000
Accumulated Depreciation	(4,531,000)
Year of Construction or Acquisition	2002
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	12,918,000
Deductions during year [Abstract]
Balance at close of year	4,531,000
Commercial-Office [Member] | Mendota Office Center III - Mendota Heights, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	3,845,000
Initial Cost to Company [Abstract]
Land	970,000
Buildings & Improvements	5,734,000
Costs capitalized subsequent to acquisition	881,000
Gross amount at which carried at close of period [Abstract]
Land	970,000
Buildings & Improvements	6,615,000
Total	7,585,000
Accumulated Depreciation	(2,129,000)
Year of Construction or Acquisition	2002
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	7,585,000
Deductions during year [Abstract]
Balance at close of year	2,129,000
Commercial-Office [Member] | Mendota Office Center IV - Mendota Heights, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	4,571,000
Initial Cost to Company [Abstract]
Land	1,070,000
Buildings & Improvements	7,635,000
Costs capitalized subsequent to acquisition	1,287,000
Gross amount at which carried at close of period [Abstract]
Land	1,070,000
Buildings & Improvements	8,922,000
Total	9,992,000
Accumulated Depreciation	(2,951,000)
Year of Construction or Acquisition	2002
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	9,992,000
Deductions during year [Abstract]
Balance at close of year	2,951,000
Commercial-Office [Member] | Minnesota National Bank - Duluth, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	707,000
Initial Cost to Company [Abstract]
Land	287,000
Buildings & Improvements	1,454,000
Costs capitalized subsequent to acquisition	224,000
Gross amount at which carried at close of period [Abstract]
Land	288,000
Buildings & Improvements	1,677,000
Total	1,965,000
Accumulated Depreciation	(413,000)
Year of Construction or Acquisition	2004
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	1,965,000
Deductions during year [Abstract]
Balance at close of year	413,000
Commercial-Office [Member] | Minot 2505 16th Street SW - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	298,000
Buildings & Improvements	1,724,000
Costs capitalized subsequent to acquisition	296,000
Gross amount at which carried at close of period [Abstract]
Land	298,000
Buildings & Improvements	2,020,000
Total	2,318,000
Accumulated Depreciation	(214,000)
Year of Construction or Acquisition	2009
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	2,318,000
Deductions during year [Abstract]
Balance at close of year	214,000
Commercial-Office [Member] | Miracle Hills One - Omaha, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	8,895,000
Initial Cost to Company [Abstract]
Land	1,974,000
Buildings & Improvements	5,726,000
Costs capitalized subsequent to acquisition	0
Gross amount at which carried at close of period [Abstract]
Land	1,974,000
Buildings & Improvements	5,726,000
Total	7,700,000
Accumulated Depreciation	0
Year of Construction or Acquisition	2006
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	7,700,000
Deductions during year [Abstract]
Balance at close of year	0
Commercial-Office [Member] | Northgate I - Maple Grove, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	4,977,000
Initial Cost to Company [Abstract]
Land	1,062,000
Buildings & Improvements	6,358,000
Costs capitalized subsequent to acquisition	990,000
Gross amount at which carried at close of period [Abstract]
Land	1,235,000
Buildings & Improvements	7,175,000
Total	8,410,000
Accumulated Depreciation	(1,850,000)
Year of Construction or Acquisition	2004
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	8,410,000
Deductions during year [Abstract]
Balance at close of year	1,850,000
Commercial-Office [Member] | Northgate II - Maple Grove, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	917,000
Initial Cost to Company [Abstract]
Land	359,000
Buildings & Improvements	1,944,000
Costs capitalized subsequent to acquisition	284,000
Gross amount at which carried at close of period [Abstract]
Land	403,000
Buildings & Improvements	2,184,000
Total	2,587,000
Accumulated Depreciation	(845,000)
Year of Construction or Acquisition	1999
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	2,587,000
Deductions during year [Abstract]
Balance at close of year	845,000
Commercial-Office [Member] | Northpark Corporate Center - Arden Hills, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	11,938,000
Initial Cost to Company [Abstract]
Land	2,034,000
Buildings & Improvements	14,584,000
Costs capitalized subsequent to acquisition	2,413,000
Gross amount at which carried at close of period [Abstract]
Land	2,037,000
Buildings & Improvements	16,994,000
Total	19,031,000
Accumulated Depreciation	(3,650,000)
Year of Construction or Acquisition	2006
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	19,031,000
Deductions during year [Abstract]
Balance at close of year	3,650,000
Commercial-Office [Member] | Omaha 10802 Farnam Dr - Omaha, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	5,182,000
Initial Cost to Company [Abstract]
Land	2,462,000
Buildings & Improvements	4,374,000
Costs capitalized subsequent to acquisition	392,000
Gross amount at which carried at close of period [Abstract]
Land	2,818,000
Buildings & Improvements	4,410,000
Total	7,228,000
Accumulated Depreciation	(397,000)
Year of Construction or Acquisition	2010
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	7,228,000
Deductions during year [Abstract]
Balance at close of year	397,000
Commercial-Office [Member] | Pacific Hills - Omaha, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	16,770,000
Initial Cost to Company [Abstract]
Land	4,220,000
Buildings & Improvements	6,280,000
Costs capitalized subsequent to acquisition	33,000
Gross amount at which carried at close of period [Abstract]
Land	4,220,000
Buildings & Improvements	6,313,000
Total	10,533,000
Accumulated Depreciation	0
Year of Construction or Acquisition	2006
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	10,533,000
Deductions during year [Abstract]
Balance at close of year	0
Commercial-Office [Member] | Plaza 16 - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	7,271,000
Initial Cost to Company [Abstract]
Land	389,000
Buildings & Improvements	5,444,000
Costs capitalized subsequent to acquisition	3,860,000
Gross amount at which carried at close of period [Abstract]
Land	598,000
Buildings & Improvements	9,095,000
Total	9,693,000
Accumulated Depreciation	(1,665,000)
Year of Construction or Acquisition	2009
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	9,693,000
Deductions during year [Abstract]
Balance at close of year	1,665,000
Commercial-Office [Member] | Plaza VII - Boise, ID [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	930,000
Initial Cost to Company [Abstract]
Land	300,000
Buildings & Improvements	3,058,000
Costs capitalized subsequent to acquisition	471,000
Gross amount at which carried at close of period [Abstract]
Land	370,000
Buildings & Improvements	3,459,000
Total	3,829,000
Accumulated Depreciation	(1,122,000)
Year of Construction or Acquisition	2003
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	3,829,000
Deductions during year [Abstract]
Balance at close of year	1,122,000
Commercial-Office [Member] | Plymouth 5095 Nathan Lane - Plymouth, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	1,182,000
Initial Cost to Company [Abstract]
Land	604,000
Buildings & Improvements	1,253,000
Costs capitalized subsequent to acquisition	82,000
Gross amount at which carried at close of period [Abstract]
Land	636,000
Buildings & Improvements	1,303,000
Total	1,939,000
Accumulated Depreciation	(224,000)
Year of Construction or Acquisition	2007
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	1,939,000
Deductions during year [Abstract]
Balance at close of year	224,000
Commercial-Office [Member] | Plymouth I - Plymouth, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	1,115,000
Initial Cost to Company [Abstract]
Land	530,000
Buildings & Improvements	1,133,000
Costs capitalized subsequent to acquisition	65,000
Gross amount at which carried at close of period [Abstract]
Land	530,000
Buildings & Improvements	1,198,000
Total	1,728,000
Accumulated Depreciation	(307,000)
Year of Construction or Acquisition	2004
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	1,728,000
Deductions during year [Abstract]
Balance at close of year	307,000
Commercial-Office [Member] | Plymouth II - Plymouth, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	1,115,000
Initial Cost to Company [Abstract]
Land	367,000
Buildings & Improvements	1,264,000
Costs capitalized subsequent to acquisition	40,000
Gross amount at which carried at close of period [Abstract]
Land	367,000
Buildings & Improvements	1,304,000
Total	1,671,000
Accumulated Depreciation	(342,000)
Year of Construction or Acquisition	2004
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	1,671,000
Deductions during year [Abstract]
Balance at close of year	342,000
Commercial-Office [Member] | Plymouth III - Plymouth, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	1,373,000
Initial Cost to Company [Abstract]
Land	507,000
Buildings & Improvements	1,495,000
Costs capitalized subsequent to acquisition	365,000
Gross amount at which carried at close of period [Abstract]
Land	507,000
Buildings & Improvements	1,860,000
Total	2,367,000
Accumulated Depreciation	(563,000)
Year of Construction or Acquisition	2004
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	2,367,000
Deductions during year [Abstract]
Balance at close of year	563,000
Commercial-Office [Member] | Plymouth IV & V - Plymouth, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	6,717,000
Initial Cost to Company [Abstract]
Land	1,336,000
Buildings & Improvements	12,693,000
Costs capitalized subsequent to acquisition	2,085,000
Gross amount at which carried at close of period [Abstract]
Land	1,338,000
Buildings & Improvements	14,776,000
Total	16,114,000
Accumulated Depreciation	(5,204,000)
Year of Construction or Acquisition	2001
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	16,114,000
Deductions during year [Abstract]
Balance at close of year	5,204,000
Commercial-Office [Member] | Prairie Oak Business Center - Eden Prairie, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	3,215,000
Initial Cost to Company [Abstract]
Land	531,000
Buildings & Improvements	4,069,000
Costs capitalized subsequent to acquisition	2,216,000
Gross amount at which carried at close of period [Abstract]
Land	784,000
Buildings & Improvements	6,032,000
Total	6,816,000
Accumulated Depreciation	(2,138,000)
Year of Construction or Acquisition	2003
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	6,816,000
Deductions during year [Abstract]
Balance at close of year	2,138,000
Commercial-Office [Member] | Rapid City 900 Concourse Drive - Rapid City, SD [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	696,000
Initial Cost to Company [Abstract]
Land	285,000
Buildings & Improvements	6,600,000
Costs capitalized subsequent to acquisition	1,028,000
Gross amount at which carried at close of period [Abstract]
Land	514,000
Buildings & Improvements	7,399,000
Total	7,913,000
Accumulated Depreciation	(2,584,000)
Year of Construction or Acquisition	2000
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	7,913,000
Deductions during year [Abstract]
Balance at close of year	2,584,000
Commercial-Office [Member] | Riverport - Maryland Heights, MO [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	19,690,000
Initial Cost to Company [Abstract]
Land	1,891,000
Buildings & Improvements	6,109,000
Costs capitalized subsequent to acquisition	107,000
Gross amount at which carried at close of period [Abstract]
Land	1,891,000
Buildings & Improvements	6,216,000
Total	8,107,000
Accumulated Depreciation	0
Year of Construction or Acquisition	2006
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	8,107,000
Deductions during year [Abstract]
Balance at close of year	0
Commercial-Office [Member] | Southeast Tech Center - Eagan, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	1,651,000
Initial Cost to Company [Abstract]
Land	560,000
Buildings & Improvements	5,496,000
Costs capitalized subsequent to acquisition	419,000
Gross amount at which carried at close of period [Abstract]
Land	569,000
Buildings & Improvements	5,906,000
Total	6,475,000
Accumulated Depreciation	(2,302,000)
Year of Construction or Acquisition	1999
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	6,475,000
Deductions during year [Abstract]
Balance at close of year	2,302,000
Commercial-Office [Member] | Spring Valley IV - Omaha, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	748,000
Initial Cost to Company [Abstract]
Land	178,000
Buildings & Improvements	916,000
Costs capitalized subsequent to acquisition	60,000
Gross amount at which carried at close of period [Abstract]
Land	186,000
Buildings & Improvements	968,000
Total	1,154,000
Accumulated Depreciation	(235,000)
Year of Construction or Acquisition	2005
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	1,154,000
Deductions during year [Abstract]
Balance at close of year	235,000
Commercial-Office [Member] | Spring Valley V - Omaha, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	823,000
Initial Cost to Company [Abstract]
Land	212,000
Buildings & Improvements	1,123,000
Costs capitalized subsequent to acquisition	251,000
Gross amount at which carried at close of period [Abstract]
Land	240,000
Buildings & Improvements	1,346,000
Total	1,586,000
Accumulated Depreciation	(342,000)
Year of Construction or Acquisition	2005
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	1,586,000
Deductions during year [Abstract]
Balance at close of year	342,000
Commercial-Office [Member] | Spring Valley X - Omaha, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	763,000
Initial Cost to Company [Abstract]
Land	180,000
Buildings & Improvements	1,024,000
Costs capitalized subsequent to acquisition	79,000
Gross amount at which carried at close of period [Abstract]
Land	189,000
Buildings & Improvements	1,094,000
Total	1,283,000
Accumulated Depreciation	(246,000)
Year of Construction or Acquisition	2005
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	1,283,000
Deductions during year [Abstract]
Balance at close of year	246,000
Commercial-Office [Member] | Spring Valley XI - Omaha, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	748,000
Initial Cost to Company [Abstract]
Land	143,000
Buildings & Improvements	1,094,000
Costs capitalized subsequent to acquisition	36,000
Gross amount at which carried at close of period [Abstract]
Land	151,000
Buildings & Improvements	1,122,000
Total	1,273,000
Accumulated Depreciation	(247,000)
Year of Construction or Acquisition	2005
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	1,273,000
Deductions during year [Abstract]
Balance at close of year	247,000
Commercial-Office [Member] | Superior Office Building - Duluth, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	1,063,000
Initial Cost to Company [Abstract]
Land	336,000
Buildings & Improvements	2,200,000
Costs capitalized subsequent to acquisition	83,000
Gross amount at which carried at close of period [Abstract]
Land	336,000
Buildings & Improvements	2,283,000
Total	2,619,000
Accumulated Depreciation	(609,000)
Year of Construction or Acquisition	2004
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	2,619,000
Deductions during year [Abstract]
Balance at close of year	609,000
Commercial-Office [Member] | TCA Building - Eagan, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	7,500,000
Initial Cost to Company [Abstract]
Land	627,000
Buildings & Improvements	8,571,000
Costs capitalized subsequent to acquisition	709,000
Gross amount at which carried at close of period [Abstract]
Land	684,000
Buildings & Improvements	9,223,000
Total	9,907,000
Accumulated Depreciation	(2,406,000)
Year of Construction or Acquisition	2003
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	9,907,000
Deductions during year [Abstract]
Balance at close of year	2,406,000
Commercial-Office [Member] | Three Paramount Plaza - Bloomington, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	1,261,000
Buildings & Improvements	6,149,000
Costs capitalized subsequent to acquisition	1,972,000
Gross amount at which carried at close of period [Abstract]
Land	1,348,000
Buildings & Improvements	8,034,000
Total	9,382,000
Accumulated Depreciation	(2,828,000)
Year of Construction or Acquisition	2002
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	9,382,000
Deductions during year [Abstract]
Balance at close of year	2,828,000
Commercial-Office [Member] | Thresher Square - Minneapolis, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	1,094,000
Buildings & Improvements	10,026,000
Costs capitalized subsequent to acquisition	1,693,000
Gross amount at which carried at close of period [Abstract]
Land	1,104,000
Buildings & Improvements	11,709,000
Total	12,813,000
Accumulated Depreciation	(3,963,000)
Year of Construction or Acquisition	2002
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	12,813,000
Deductions during year [Abstract]
Balance at close of year	3,963,000
Commercial-Office [Member] | Timberlands - Leawood, KS [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	13,155,000
Initial Cost to Company [Abstract]
Land	2,375,000
Buildings & Improvements	9,601,000
Costs capitalized subsequent to acquisition	36,000
Gross amount at which carried at close of period [Abstract]
Land	2,375,000
Buildings & Improvements	9,637,000
Total	12,012,000
Accumulated Depreciation	0
Year of Construction or Acquisition	2006
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	12,012,000
Deductions during year [Abstract]
Balance at close of year	0
Commercial-Office [Member] | UHC Office - International Falls, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	900,000
Initial Cost to Company [Abstract]
Land	119,000
Buildings & Improvements	2,366,000
Costs capitalized subsequent to acquisition	80,000
Gross amount at which carried at close of period [Abstract]
Land	119,000
Buildings & Improvements	2,446,000
Total	2,565,000
Accumulated Depreciation	(656,000)
Year of Construction or Acquisition	2004
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	2,565,000
Deductions during year [Abstract]
Balance at close of year	656,000
Commercial-Office [Member] | US Bank Financial Center - Bloomington, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	13,104,000
Initial Cost to Company [Abstract]
Land	3,117,000
Buildings & Improvements	13,350,000
Costs capitalized subsequent to acquisition	1,586,000
Gross amount at which carried at close of period [Abstract]
Land	3,119,000
Buildings & Improvements	14,934,000
Total	18,053,000
Accumulated Depreciation	(3,254,000)
Year of Construction or Acquisition	2005
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	18,053,000
Deductions during year [Abstract]
Balance at close of year	3,254,000
Commercial-Office [Member] | Wells Fargo Center - St Cloud, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	6,002,000
Initial Cost to Company [Abstract]
Land	869,000
Buildings & Improvements	8,373,000
Costs capitalized subsequent to acquisition	1,448,000
Gross amount at which carried at close of period [Abstract]
Land	869,000
Buildings & Improvements	9,821,000
Total	10,690,000
Accumulated Depreciation	(2,375,000)
Year of Construction or Acquisition	2005
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	10,690,000
Deductions during year [Abstract]
Balance at close of year	2,375,000
Commercial-Office [Member] | West River Business Park - Waite Park, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	491,000
Initial Cost to Company [Abstract]
Land	235,000
Buildings & Improvements	1,195,000
Costs capitalized subsequent to acquisition	241,000
Gross amount at which carried at close of period [Abstract]
Land	235,000
Buildings & Improvements	1,436,000
Total	1,671,000
Accumulated Depreciation	(371,000)
Year of Construction or Acquisition	2003
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	1,671,000
Deductions during year [Abstract]
Balance at close of year	371,000
Commercial-Office [Member] | Westgate - Boise, ID [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	3,989,000
Initial Cost to Company [Abstract]
Land	1,000,000
Buildings & Improvements	10,618,000
Costs capitalized subsequent to acquisition	1,933,000
Gross amount at which carried at close of period [Abstract]
Land	1,000,000
Buildings & Improvements	12,551,000
Total	13,551,000
Accumulated Depreciation	(4,046,000)
Year of Construction or Acquisition	2003
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	13,551,000
Deductions during year [Abstract]
Balance at close of year	4,046,000
Commercial-Office [Member] | Whitewater Plaza - Minnetonka, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	3,762,000
Initial Cost to Company [Abstract]
Land	530,000
Buildings & Improvements	4,860,000
Costs capitalized subsequent to acquisition	1,068,000
Gross amount at which carried at close of period [Abstract]
Land	577,000
Buildings & Improvements	5,881,000
Total	6,458,000
Accumulated Depreciation	(1,982,000)
Year of Construction or Acquisition	2002
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	6,458,000
Deductions during year [Abstract]
Balance at close of year	1,982,000
Commercial-Office [Member] | Wirth Corporate Center - Golden Valley, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	970,000
Buildings & Improvements	3,760,000
Costs capitalized subsequent to acquisition	0
Gross amount at which carried at close of period [Abstract]
Land	970,000
Buildings & Improvements	3,760,000
Total	4,730,000
Accumulated Depreciation	0
Year of Construction or Acquisition	2002
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	4,730,000
Deductions during year [Abstract]
Balance at close of year	0
Commercial-Office [Member] | Woodlands Plaza IV - Maryland Heights, MO [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	4,360,000
Initial Cost to Company [Abstract]
Land	771,000
Buildings & Improvements	4,609,000
Costs capitalized subsequent to acquisition	1,466,000
Gross amount at which carried at close of period [Abstract]
Land	862,000
Buildings & Improvements	5,984,000
Total	6,846,000
Accumulated Depreciation	(1,261,000)
Year of Construction or Acquisition	2006
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	6,846,000
Deductions during year [Abstract]
Balance at close of year	1,261,000
Commercial-Office [Member] | Minot 1400 31st Ave - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	1,026,000
Buildings & Improvements	6,143,000
Costs capitalized subsequent to acquisition	4,404,000
Gross amount at which carried at close of period [Abstract]
Land	1,038,000
Buildings & Improvements	10,535,000
Total	11,573,000
Accumulated Depreciation	(1,670,000)
Year of Construction or Acquisition	2010
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	11,573,000
Deductions during year [Abstract]
Balance at close of year	1,670,000
Commercial-Office [Member] | Wholly Owned Properties [Member]
Additions during year [Abstract]
Additions	0		0		0
Commercial Healthcare [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	243,714,000
Initial Cost to Company [Abstract]
Land	33,906,000
Buildings & Improvements	440,157,000
Costs capitalized subsequent to acquisition	50,965,000
Gross amount at which carried at close of period [Abstract]
Land	34,544,000
Buildings & Improvements	490,484,000
Total	525,028,000
Accumulated Depreciation	(105,843,000)
Deductions during year [Abstract]
Balance at close of year	525,028,000
Deductions during year [Abstract]
Balance at close of year	105,843,000
Commercial Healthcare [Member] | 2800 Medical Building - Minneapolis, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	5,203,000
Initial Cost to Company [Abstract]
Land	204,000
Buildings & Improvements	7,135,000
Costs capitalized subsequent to acquisition	2,246,000
Gross amount at which carried at close of period [Abstract]
Land	229,000
Buildings & Improvements	9,356,000
Total	9,585,000
Accumulated Depreciation	(2,691,000)
Year of Construction or Acquisition	2005
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	9,585,000
Deductions during year [Abstract]
Balance at close of year	2,691,000
Commercial Healthcare [Member] | 2828 Chicago Avenue - Minneapolis, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	8,217,000
Initial Cost to Company [Abstract]
Land	726,000
Buildings & Improvements	11,319,000
Costs capitalized subsequent to acquisition	5,627,000
Gross amount at which carried at close of period [Abstract]
Land	729,000
Buildings & Improvements	16,943,000
Total	17,672,000
Accumulated Depreciation	(3,388,000)
Year of Construction or Acquisition	2007
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	17,672,000
Deductions during year [Abstract]
Balance at close of year	3,388,000
Commercial Healthcare [Member] | Airport Medical - Bloomington, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	769,000
Initial Cost to Company [Abstract]
Land	0
Buildings & Improvements	4,678,000
Costs capitalized subsequent to acquisition	0
Gross amount at which carried at close of period [Abstract]
Land	0
Buildings & Improvements	4,678,000
Total	4,678,000
Accumulated Depreciation	(1,614,000)
Year of Construction or Acquisition	2002
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	4,678,000
Deductions during year [Abstract]
Balance at close of year	1,614,000
Commercial Healthcare [Member] | Barry Pointe Office Park - Kansas City, MO [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	1,403,000
Initial Cost to Company [Abstract]
Land	384,000
Buildings & Improvements	2,366,000
Costs capitalized subsequent to acquisition	143,000
Gross amount at which carried at close of period [Abstract]
Land	392,000
Buildings & Improvements	2,501,000
Total	2,893,000
Accumulated Depreciation	(467,000)
Year of Construction or Acquisition	2007
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	2,893,000
Deductions during year [Abstract]
Balance at close of year	467,000
Commercial Healthcare [Member] | Billings 2300 Grant Road - Billings, MT [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	1,447,000
Initial Cost to Company [Abstract]
Land	649,000
Buildings & Improvements	1,216,000
Costs capitalized subsequent to acquisition	0
Gross amount at which carried at close of period [Abstract]
Land	649,000
Buildings & Improvements	1,216,000
Total	1,865,000
Accumulated Depreciation	(115,000)
Year of Construction or Acquisition	2010
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	1,865,000
Deductions during year [Abstract]
Balance at close of year	115,000
Commercial Healthcare [Member] | Burnsville 303 Nicollet Medical (Ridgeview) - Burnsville, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	8,273,000
Initial Cost to Company [Abstract]
Land	1,071,000
Buildings & Improvements	6,842,000
Costs capitalized subsequent to acquisition	1,602,000
Gross amount at which carried at close of period [Abstract]
Land	1,071,000
Buildings & Improvements	8,444,000
Total	9,515,000
Accumulated Depreciation	(1,328,000)
Year of Construction or Acquisition	2008
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	9,515,000
Deductions during year [Abstract]
Balance at close of year	1,328,000
Commercial Healthcare [Member] | Burnsville 305 Nicollet Medical (Ridgeview South) - Burnsville, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	5,179,000
Initial Cost to Company [Abstract]
Land	189,000
Buildings & Improvements	5,127,000
Costs capitalized subsequent to acquisition	956,000
Gross amount at which carried at close of period [Abstract]
Land	189,000
Buildings & Improvements	6,083,000
Total	6,272,000
Accumulated Depreciation	(901,000)
Year of Construction or Acquisition	2008
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	6,272,000
Deductions during year [Abstract]
Balance at close of year	901,000
Commercial Healthcare [Member] | Casper 1930 E 12th Street (Park Place) - Casper, WY [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	439,000
Buildings & Improvements	5,780,000
Costs capitalized subsequent to acquisition	162,000
Gross amount at which carried at close of period [Abstract]
Land	439,000
Buildings & Improvements	5,942,000
Total	6,381,000
Accumulated Depreciation	(692,000)
Year of Construction or Acquisition	2009
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	6,381,000
Deductions during year [Abstract]
Balance at close of year	692,000
Commercial Healthcare [Member] | Casper 3955 E 12th Street (Meadow Wind) - Casper, WY [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	388,000
Buildings & Improvements	10,494,000
Costs capitalized subsequent to acquisition	181,000
Gross amount at which carried at close of period [Abstract]
Land	459,000
Buildings & Improvements	10,604,000
Total	11,063,000
Accumulated Depreciation	(1,130,000)
Year of Construction or Acquisition	2009
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	11,063,000
Deductions during year [Abstract]
Balance at close of year	1,130,000
Commercial Healthcare [Member] | Cheyenne 4010 N College Drive (Aspen Wind) - Cheyenne, WY [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	628,000
Buildings & Improvements	10,272,000
Costs capitalized subsequent to acquisition	260,000
Gross amount at which carried at close of period [Abstract]
Land	629,000
Buildings & Improvements	10,531,000
Total	11,160,000
Accumulated Depreciation	(1,180,000)
Year of Construction or Acquisition	2009
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	11,160,000
Deductions during year [Abstract]
Balance at close of year	1,180,000
Commercial Healthcare [Member] | Cheyenne 4606 N College Drive (Sierra Hills) - Cheyenne, WY [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	695,000
Buildings & Improvements	7,455,000
Costs capitalized subsequent to acquisition	40,000
Gross amount at which carried at close of period [Abstract]
Land	695,000
Buildings & Improvements	7,495,000
Total	8,190,000
Accumulated Depreciation	(830,000)
Year of Construction or Acquisition	2009
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	8,190,000
Deductions during year [Abstract]
Balance at close of year	830,000
Commercial Healthcare [Member] | Denfeld Clinic - Duluth, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	1,546,000
Initial Cost to Company [Abstract]
Land	501,000
Buildings & Improvements	2,597,000
Costs capitalized subsequent to acquisition	1,000
Gross amount at which carried at close of period [Abstract]
Land	501,000
Buildings & Improvements	2,598,000
Total	3,099,000
Accumulated Depreciation	(653,000)
Year of Construction or Acquisition	2004
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	3,099,000
Deductions during year [Abstract]
Balance at close of year	653,000
Commercial Healthcare [Member] | Eagan 1440 Duckwood Medical - Eagan, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	521,000
Buildings & Improvements	1,547,000
Costs capitalized subsequent to acquisition	519,000
Gross amount at which carried at close of period [Abstract]
Land	521,000
Buildings & Improvements	2,066,000
Total	2,587,000
Accumulated Depreciation	(541,000)
Year of Construction or Acquisition	2008
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	2,587,000
Deductions during year [Abstract]
Balance at close of year	541,000
Commercial Healthcare [Member] | Edgewood Vista - Belgrade, MT [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	35,000
Buildings & Improvements	779,000
Costs capitalized subsequent to acquisition	6,000
Gross amount at which carried at close of period [Abstract]
Land	35,000
Buildings & Improvements	785,000
Total	820,000
Accumulated Depreciation	(120,000)
Year of Construction or Acquisition	2008
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	820,000
Deductions during year [Abstract]
Balance at close of year	120,000
Commercial Healthcare [Member] | Edgewood Vista - Billings, MT [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	1,844,000
Initial Cost to Company [Abstract]
Land	115,000
Buildings & Improvements	1,767,000
Costs capitalized subsequent to acquisition	10,000
Gross amount at which carried at close of period [Abstract]
Land	115,000
Buildings & Improvements	1,777,000
Total	1,892,000
Accumulated Depreciation	(275,000)
Year of Construction or Acquisition	2008
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	1,892,000
Deductions during year [Abstract]
Balance at close of year	275,000
Commercial Healthcare [Member] | Edgewood Vista - Bismarck, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	511,000
Buildings & Improvements	9,193,000
Costs capitalized subsequent to acquisition	139,000
Gross amount at which carried at close of period [Abstract]
Land	511,000
Buildings & Improvements	9,332,000
Total	9,843,000
Accumulated Depreciation	(1,993,000)
Year of Construction or Acquisition	2005
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	9,843,000
Deductions during year [Abstract]
Balance at close of year	1,993,000
Commercial Healthcare [Member] | Edgewood Vista - Brainerd, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	587,000
Buildings & Improvements	8,999,000
Costs capitalized subsequent to acquisition	79,000
Gross amount at which carried at close of period [Abstract]
Land	587,000
Buildings & Improvements	9,078,000
Total	9,665,000
Accumulated Depreciation	(1,950,000)
Year of Construction or Acquisition	2005
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	9,665,000
Deductions during year [Abstract]
Balance at close of year	1,950,000
Commercial Healthcare [Member] | Edgewood Vista - Columbus, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	43,000
Buildings & Improvements	824,000
Costs capitalized subsequent to acquisition	3,000
Gross amount at which carried at close of period [Abstract]
Land	44,000
Buildings & Improvements	826,000
Total	870,000
Accumulated Depreciation	(126,000)
Year of Construction or Acquisition	2008
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	870,000
Deductions during year [Abstract]
Balance at close of year	126,000
Commercial Healthcare [Member] | Edgewood Vista - East Grand Forks, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	2,809,000
Initial Cost to Company [Abstract]
Land	290,000
Buildings & Improvements	1,352,000
Costs capitalized subsequent to acquisition	24,000
Gross amount at which carried at close of period [Abstract]
Land	290,000
Buildings & Improvements	1,376,000
Total	1,666,000
Accumulated Depreciation	(213,000)
Year of Construction or Acquisition	2000
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	1,666,000
Deductions during year [Abstract]
Balance at close of year	213,000
Commercial Healthcare [Member] | Edgewood Vista - Fargo, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	12,418,000
Initial Cost to Company [Abstract]
Land	775,000
Buildings & Improvements	20,870,000
Costs capitalized subsequent to acquisition	13,000
Gross amount at which carried at close of period [Abstract]
Land	775,000
Buildings & Improvements	20,883,000
Total	21,658,000
Accumulated Depreciation	(3,197,000)
Year of Construction or Acquisition	2008
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	21,658,000
Deductions during year [Abstract]
Balance at close of year	3,197,000
Commercial Healthcare [Member] | Edgewood Vista - Fremont, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	573,000
Initial Cost to Company [Abstract]
Land	56,000
Buildings & Improvements	490,000
Costs capitalized subsequent to acquisition	43,000
Gross amount at which carried at close of period [Abstract]
Land	56,000
Buildings & Improvements	533,000
Total	589,000
Accumulated Depreciation	(166,000)
Year of Construction or Acquisition	2008
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	589,000
Deductions during year [Abstract]
Balance at close of year	166,000
Commercial Healthcare [Member] | Edgewood Vista - Grand Island, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	33,000
Buildings & Improvements	773,000
Costs capitalized subsequent to acquisition	31,000
Gross amount at which carried at close of period [Abstract]
Land	39,000
Buildings & Improvements	798,000
Total	837,000
Accumulated Depreciation	(120,000)
Year of Construction or Acquisition	2008
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	837,000
Deductions during year [Abstract]
Balance at close of year	120,000
Commercial Healthcare [Member] | Edgewood Vista - Hastings, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	590,000
Initial Cost to Company [Abstract]
Land	49,000
Buildings & Improvements	517,000
Costs capitalized subsequent to acquisition	46,000
Gross amount at which carried at close of period [Abstract]
Land	50,000
Buildings & Improvements	562,000
Total	612,000
Accumulated Depreciation	(181,000)
Year of Construction or Acquisition	2008
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	612,000
Deductions during year [Abstract]
Balance at close of year	181,000
Commercial Healthcare [Member] | Edgewood Vista - Hermantown I, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	15,823,000
Initial Cost to Company [Abstract]
Land	288,000
Buildings & Improvements	9,871,000
Costs capitalized subsequent to acquisition	1,520,000
Gross amount at which carried at close of period [Abstract]
Land	288,000
Buildings & Improvements	11,391,000
Total	11,679,000
Accumulated Depreciation	(3,589,000)
Year of Construction or Acquisition	2000
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	11,679,000
Deductions during year [Abstract]
Balance at close of year	3,589,000
Commercial Healthcare [Member] | Edgewood Vista - Hermantown II, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	719,000
Buildings & Improvements	10,517,000
Costs capitalized subsequent to acquisition	33,000
Gross amount at which carried at close of period [Abstract]
Land	719,000
Buildings & Improvements	10,550,000
Total	11,269,000
Accumulated Depreciation	(2,273,000)
Year of Construction or Acquisition	2005
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	11,269,000
Deductions during year [Abstract]
Balance at close of year	2,273,000
Commercial Healthcare [Member] | Edgewood Vista - Kalispell, MT [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	592,000
Initial Cost to Company [Abstract]
Land	70,000
Buildings & Improvements	502,000
Costs capitalized subsequent to acquisition	615,000
Gross amount at which carried at close of period [Abstract]
Land	70,000
Buildings & Improvements	1,117,000
Total	1,187,000
Accumulated Depreciation	(287,000)
Year of Construction or Acquisition	2001
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	1,187,000
Deductions during year [Abstract]
Balance at close of year	287,000
Commercial Healthcare [Member] | Edgewood Vista - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	9,250,000
Initial Cost to Company [Abstract]
Land	1,045,000
Buildings & Improvements	11,590,000
Costs capitalized subsequent to acquisition	77,000
Gross amount at which carried at close of period [Abstract]
Land	1,047,000
Buildings & Improvements	11,665,000
Total	12,712,000
Accumulated Depreciation	(1,007,000)
Year of Construction or Acquisition	2010
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	12,712,000
Deductions during year [Abstract]
Balance at close of year	1,007,000
Commercial Healthcare [Member] | Edgewood Vista - Missoula, MT [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	840,000
Initial Cost to Company [Abstract]
Land	109,000
Buildings & Improvements	854,000
Costs capitalized subsequent to acquisition	74,000
Gross amount at which carried at close of period [Abstract]
Land	116,000
Buildings & Improvements	921,000
Total	1,037,000
Accumulated Depreciation	(385,000)
Year of Construction or Acquisition	1996
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	1,037,000
Deductions during year [Abstract]
Balance at close of year	385,000
Commercial Healthcare [Member] | Edgewood Vista - Norfolk, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	42,000
Buildings & Improvements	722,000
Costs capitalized subsequent to acquisition	9,000
Gross amount at which carried at close of period [Abstract]
Land	42,000
Buildings & Improvements	731,000
Total	773,000
Accumulated Depreciation	(112,000)
Year of Construction or Acquisition	2008
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	773,000
Deductions during year [Abstract]
Balance at close of year	112,000
Commercial Healthcare [Member] | Edgewood Vista - Omaha, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	374,000
Initial Cost to Company [Abstract]
Land	89,000
Buildings & Improvements	547,000
Costs capitalized subsequent to acquisition	45,000
Gross amount at which carried at close of period [Abstract]
Land	89,000
Buildings & Improvements	592,000
Total	681,000
Accumulated Depreciation	(186,000)
Year of Construction or Acquisition	2001
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	681,000
Deductions during year [Abstract]
Balance at close of year	186,000
Commercial Healthcare [Member] | Edgewood Vista - Sioux Falls, SD [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	1,056,000
Initial Cost to Company [Abstract]
Land	314,000
Buildings & Improvements	974,000
Costs capitalized subsequent to acquisition	40,000
Gross amount at which carried at close of period [Abstract]
Land	314,000
Buildings & Improvements	1,014,000
Total	1,328,000
Accumulated Depreciation	(155,000)
Year of Construction or Acquisition	2008
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	1,328,000
Deductions during year [Abstract]
Balance at close of year	155,000
Commercial Healthcare [Member] | Edgewood Vista - Spearfish, SD [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	315,000
Buildings & Improvements	8,584,000
Costs capitalized subsequent to acquisition	69,000
Gross amount at which carried at close of period [Abstract]
Land	330,000
Buildings & Improvements	8,638,000
Total	8,968,000
Accumulated Depreciation	(1,489,000)
Year of Construction or Acquisition	2005
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	8,968,000
Deductions during year [Abstract]
Balance at close of year	1,489,000
Commercial Healthcare [Member] | Edgewood Vista - Virginia, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	13,460,000
Initial Cost to Company [Abstract]
Land	246,000
Buildings & Improvements	11,823,000
Costs capitalized subsequent to acquisition	137,000
Gross amount at which carried at close of period [Abstract]
Land	246,000
Buildings & Improvements	11,960,000
Total	12,206,000
Accumulated Depreciation	(3,357,000)
Year of Construction or Acquisition	2002
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	12,206,000
Deductions during year [Abstract]
Balance at close of year	3,357,000
Commercial Healthcare [Member] | Edina 6363 France Medical - Edina, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	9,830,000
Initial Cost to Company [Abstract]
Land	0
Buildings & Improvements	12,675,000
Costs capitalized subsequent to acquisition	2,500,000
Gross amount at which carried at close of period [Abstract]
Land	0
Buildings & Improvements	15,175,000
Total	15,175,000
Accumulated Depreciation	(3,114,000)
Year of Construction or Acquisition	2008
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	15,175,000
Deductions during year [Abstract]
Balance at close of year	3,114,000
Commercial Healthcare [Member] | Edina 6405 France Medical - Edina, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	8,473,000
Initial Cost to Company [Abstract]
Land	0
Buildings & Improvements	12,201,000
Costs capitalized subsequent to acquisition	41,000
Gross amount at which carried at close of period [Abstract]
Land	0
Buildings & Improvements	12,242,000
Total	12,242,000
Accumulated Depreciation	(2,532,000)
Year of Construction or Acquisition	2008
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	12,242,000
Deductions during year [Abstract]
Balance at close of year	2,532,000
Commercial Healthcare [Member] | Edina 6517 Drew Avenue - Edina, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	353,000
Buildings & Improvements	660,000
Costs capitalized subsequent to acquisition	529,000
Gross amount at which carried at close of period [Abstract]
Land	372,000
Buildings & Improvements	1,170,000
Total	1,542,000
Accumulated Depreciation	(519,000)
Year of Construction or Acquisition	2002
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	1,542,000
Deductions during year [Abstract]
Balance at close of year	519,000
Commercial Healthcare [Member] | Edina 6525 Drew Avenue - Edina, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	388,000
Buildings & Improvements	117,000
Costs capitalized subsequent to acquisition	0
Gross amount at which carried at close of period [Abstract]
Land	388,000
Buildings & Improvements	117,000
Total	505,000
Accumulated Depreciation	(7,000)
Year of Construction or Acquisition	2011
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	505,000
Deductions during year [Abstract]
Balance at close of year	7,000
Commercial Healthcare [Member] | Edina 6525 France SMC II - Edina, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	9,991,000
Initial Cost to Company [Abstract]
Land	755,000
Buildings & Improvements	8,054,000
Costs capitalized subsequent to acquisition	5,982,000
Gross amount at which carried at close of period [Abstract]
Land	1,040,000
Buildings & Improvements	13,751,000
Total	14,791,000
Accumulated Depreciation	(5,805,000)
Year of Construction or Acquisition	2003
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	14,791,000
Deductions during year [Abstract]
Balance at close of year	5,805,000
Commercial Healthcare [Member] | Edina 6545 France SMC I - Edina MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	30,219,000
Initial Cost to Company [Abstract]
Land	3,480,000
Buildings & Improvements	30,743,000
Costs capitalized subsequent to acquisition	14,758,000
Gross amount at which carried at close of period [Abstract]
Land	3,480,000
Buildings & Improvements	45,501,000
Total	48,981,000
Accumulated Depreciation	(16,225,000)
Year of Construction or Acquisition	2001
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	48,981,000
Deductions during year [Abstract]
Balance at close of year	16,225,000
Commercial Healthcare [Member] | Fresenius - Duluth, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	648,000
Initial Cost to Company [Abstract]
Land	50,000
Buildings & Improvements	1,520,000
Costs capitalized subsequent to acquisition	2,000
Gross amount at which carried at close of period [Abstract]
Land	50,000
Buildings & Improvements	1,522,000
Total	1,572,000
Accumulated Depreciation	(382,000)
Year of Construction or Acquisition	2004
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	1,572,000
Deductions during year [Abstract]
Balance at close of year	382,000
Commercial Healthcare [Member] | Garden View - St. Paul, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	785,000
Initial Cost to Company [Abstract]
Land	0
Buildings & Improvements	7,408,000
Costs capitalized subsequent to acquisition	644,000
Gross amount at which carried at close of period [Abstract]
Land	12,000
Buildings & Improvements	8,040,000
Total	8,052,000
Accumulated Depreciation	(2,466,000)
Year of Construction or Acquisition	2002
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	8,052,000
Deductions during year [Abstract]
Balance at close of year	2,466,000
Commercial Healthcare [Member] | Gateway Clinic - Sandstone, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	895,000
Initial Cost to Company [Abstract]
Land	66,000
Buildings & Improvements	1,699,000
Costs capitalized subsequent to acquisition	1,000
Gross amount at which carried at close of period [Abstract]
Land	66,000
Buildings & Improvements	1,700,000
Total	1,766,000
Accumulated Depreciation	(427,000)
Year of Construction or Acquisition	2004
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	1,766,000
Deductions during year [Abstract]
Balance at close of year	427,000
Commercial Healthcare [Member] | Healtheast St John & Woodwinds - Maplewood & Woodbury, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	8,947,000
Initial Cost to Company [Abstract]
Land	3,239,000
Buildings & Improvements	18,362,000
Costs capitalized subsequent to acquisition	0
Gross amount at which carried at close of period [Abstract]
Land	3,239,000
Buildings & Improvements	18,362,000
Total	21,601,000
Accumulated Depreciation	(6,407,000)
Year of Construction or Acquisition	2000
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	21,601,000
Deductions during year [Abstract]
Balance at close of year	6,407,000
Commercial Healthcare [Member] | High Pointe Health Campus - Lake Elmo, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	7,500,000
Initial Cost to Company [Abstract]
Land	1,305,000
Buildings & Improvements	10,528,000
Costs capitalized subsequent to acquisition	1,678,000
Gross amount at which carried at close of period [Abstract]
Land	1,329,000
Buildings & Improvements	12,182,000
Total	13,511,000
Accumulated Depreciation	(3,320,000)
Year of Construction or Acquisition	2004
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	13,511,000
Deductions during year [Abstract]
Balance at close of year	3,320,000
Commercial Healthcare [Member] | Jamestown Medical Office Building - Jamestown, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	6,078,000
Initial Cost to Company [Abstract]
Land	0
Buildings & Improvements	7,622,000
Costs capitalized subsequent to acquisition	0
Gross amount at which carried at close of period [Abstract]
Land	0
Buildings & Improvements	7,622,000
Total	7,622,000
Accumulated Depreciation	(464,000)
Year of Construction or Acquisition	2013
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	7,622,000
Deductions during year [Abstract]
Balance at close of year	464,000
Commercial Healthcare [Member] | Laramie 1072 N 22nd Street (Spring Wind) - Laramie, WY [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	406,000
Buildings & Improvements	10,151,000
Costs capitalized subsequent to acquisition	17,000
Gross amount at which carried at close of period [Abstract]
Land	406,000
Buildings & Improvements	10,168,000
Total	10,574,000
Accumulated Depreciation	(941,000)
Year of Construction or Acquisition	2009
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	10,574,000
Deductions during year [Abstract]
Balance at close of year	941,000
Commercial Healthcare [Member] | Legends at Heritage Place - Sartell, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	970,000
Buildings & Improvements	9,920,000
Costs capitalized subsequent to acquisition	0
Gross amount at which carried at close of period [Abstract]
Land	970,000
Buildings & Improvements	9,920,000
Total	10,890,000
Accumulated Depreciation	(134,000)
Deductions during year [Abstract]
Balance at close of year	10,890,000
Deductions during year [Abstract]
Balance at close of year	134,000
Commercial Healthcare [Member] | Mariner Clinic - Superior, WI [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	1,958,000
Initial Cost to Company [Abstract]
Land	0
Buildings & Improvements	3,781,000
Costs capitalized subsequent to acquisition	90,000
Gross amount at which carried at close of period [Abstract]
Land	20,000
Buildings & Improvements	3,851,000
Total	3,871,000
Accumulated Depreciation	(974,000)
Year of Construction or Acquisition	2004
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	3,871,000
Deductions during year [Abstract]
Balance at close of year	974,000
Commercial Healthcare [Member] | Minneapolis 701 25th Avenue Medical - Minneapolis, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	7,368,000
Initial Cost to Company [Abstract]
Land	0
Buildings & Improvements	7,873,000
Costs capitalized subsequent to acquisition	1,551,000
Gross amount at which carried at close of period [Abstract]
Land	0
Buildings & Improvements	9,424,000
Total	9,424,000
Accumulated Depreciation	(1,471,000)
Year of Construction or Acquisition	2008
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	9,424,000
Deductions during year [Abstract]
Balance at close of year	1,471,000
Commercial Healthcare [Member] | Missoula 3050 Great Northern - Missoula, MT [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	1,510,000
Initial Cost to Company [Abstract]
Land	640,000
Buildings & Improvements	1,331,000
Costs capitalized subsequent to acquisition	0
Gross amount at which carried at close of period [Abstract]
Land	640,000
Buildings & Improvements	1,331,000
Total	1,971,000
Accumulated Depreciation	(126,000)
Year of Construction or Acquisition	2010
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	1,971,000
Deductions during year [Abstract]
Balance at close of year	126,000
Commercial Healthcare [Member] | Nebraska Orthopaedic Hospital - Omaha, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	11,516,000
Initial Cost to Company [Abstract]
Land	0
Buildings & Improvements	20,272,000
Costs capitalized subsequent to acquisition	1,615,000
Gross amount at which carried at close of period [Abstract]
Land	0
Buildings & Improvements	21,887,000
Total	21,887,000
Accumulated Depreciation	(5,353,000)
Year of Construction or Acquisition	2004
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	21,887,000
Deductions during year [Abstract]
Balance at close of year	5,353,000
Commercial Healthcare [Member] | Park Dental - Brooklyn Center, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	441,000
Initial Cost to Company [Abstract]
Land	185,000
Buildings & Improvements	2,767,000
Costs capitalized subsequent to acquisition	0
Gross amount at which carried at close of period [Abstract]
Land	185,000
Buildings & Improvements	2,767,000
Total	2,952,000
Accumulated Depreciation	(804,000)
Year of Construction or Acquisition	2002
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	2,952,000
Deductions during year [Abstract]
Balance at close of year	804,000
Commercial Healthcare [Member] | Pavilion I - Duluth, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	5,159,000
Initial Cost to Company [Abstract]
Land	1,245,000
Buildings & Improvements	8,898,000
Costs capitalized subsequent to acquisition	31,000
Gross amount at which carried at close of period [Abstract]
Land	1,245,000
Buildings & Improvements	8,929,000
Total	10,174,000
Accumulated Depreciation	(2,219,000)
Year of Construction or Acquisition	2004
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	10,174,000
Deductions during year [Abstract]
Balance at close of year	2,219,000
Commercial Healthcare [Member] | Pavilion II - Duluth, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	9,494,000
Initial Cost to Company [Abstract]
Land	2,715,000
Buildings & Improvements	14,673,000
Costs capitalized subsequent to acquisition	1,937,000
Gross amount at which carried at close of period [Abstract]
Land	2,715,000
Buildings & Improvements	16,610,000
Total	19,325,000
Accumulated Depreciation	(5,264,000)
Year of Construction or Acquisition	2004
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	19,325,000
Deductions during year [Abstract]
Balance at close of year	5,264,000
Commercial Healthcare [Member] | Ritchie Medical Plaza - St Paul, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	6,228,000
Initial Cost to Company [Abstract]
Land	1,615,000
Buildings & Improvements	7,851,000
Costs capitalized subsequent to acquisition	3,481,000
Gross amount at which carried at close of period [Abstract]
Land	1,647,000
Buildings & Improvements	11,300,000
Total	12,947,000
Accumulated Depreciation	(2,350,000)
Year of Construction or Acquisition	2005
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	12,947,000
Deductions during year [Abstract]
Balance at close of year	2,350,000
Commercial Healthcare [Member] | Sartell 2000 23rd Street South - Sartell, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	2,456,000
Initial Cost to Company [Abstract]
Land	0
Buildings & Improvements	11,781,000
Costs capitalized subsequent to acquisition	934,000
Gross amount at which carried at close of period [Abstract]
Land	0
Buildings & Improvements	12,715,000
Total	12,715,000
Accumulated Depreciation	(3,782,000)
Year of Construction or Acquisition	2002
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	12,715,000
Deductions during year [Abstract]
Balance at close of year	3,782,000
Commercial Healthcare [Member] | Spring Creek American Falls- American Falls, ID [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	2,210,000
Initial Cost to Company [Abstract]
Land	145,000
Buildings & Improvements	3,870,000
Costs capitalized subsequent to acquisition	0
Gross amount at which carried at close of period [Abstract]
Land	145,000
Buildings & Improvements	3,870,000
Total	4,015,000
Accumulated Depreciation	(292,000)
Year of Construction or Acquisition	2011
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	4,015,000
Deductions during year [Abstract]
Balance at close of year	292,000
Commercial Healthcare [Member] | Spring Creek-Boise - Boise, ID [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	2,857,000
Initial Cost to Company [Abstract]
Land	708,000
Buildings & Improvements	4,296,000
Costs capitalized subsequent to acquisition	0
Gross amount at which carried at close of period [Abstract]
Land	708,000
Buildings & Improvements	4,296,000
Total	5,004,000
Accumulated Depreciation	(348,000)
Year of Construction or Acquisition	2011
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	5,004,000
Deductions during year [Abstract]
Balance at close of year	348,000
Commercial Healthcare [Member] | Spring Creek-Eagle - Eagle, ID [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	2,034,000
Initial Cost to Company [Abstract]
Land	263,000
Buildings & Improvements	3,775,000
Costs capitalized subsequent to acquisition	0
Gross amount at which carried at close of period [Abstract]
Land	263,000
Buildings & Improvements	3,775,000
Total	4,038,000
Accumulated Depreciation	(286,000)
Year of Construction or Acquisition	2011
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	4,038,000
Deductions during year [Abstract]
Balance at close of year	286,000
Commercial Healthcare [Member] | Spring Creek Fruitland - Fruitland, ID [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	550,000
Buildings & Improvements	6,565,000
Costs capitalized subsequent to acquisition	0
Gross amount at which carried at close of period [Abstract]
Land	550,000
Buildings & Improvements	6,565,000
Total	7,115,000
Accumulated Depreciation	(57,000)
Deductions during year [Abstract]
Balance at close of year	7,115,000
Deductions during year [Abstract]
Balance at close of year	57,000
Commercial Healthcare [Member] | Spring Creek-Meridian - Meridian, ID [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	3,360,000
Initial Cost to Company [Abstract]
Land	424,000
Buildings & Improvements	6,724,000
Costs capitalized subsequent to acquisition	0
Gross amount at which carried at close of period [Abstract]
Land	424,000
Buildings & Improvements	6,724,000
Total	7,148,000
Accumulated Depreciation	(504,000)
Year of Construction or Acquisition	2011
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	7,148,000
Deductions during year [Abstract]
Balance at close of year	504,000
Commercial Healthcare [Member] | Spring Creek-Overland - Overland, ID [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	3,225,000
Initial Cost to Company [Abstract]
Land	687,000
Buildings & Improvements	5,942,000
Costs capitalized subsequent to acquisition	0
Gross amount at which carried at close of period [Abstract]
Land	687,000
Buildings & Improvements	5,942,000
Total	6,629,000
Accumulated Depreciation	(465,000)
Year of Construction or Acquisition	2011
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	6,629,000
Deductions during year [Abstract]
Balance at close of year	465,000
Commercial Healthcare [Member] | Spring Creek-Soda Springs - Soda Springs, ID [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	796,000
Initial Cost to Company [Abstract]
Land	66,000
Buildings & Improvements	2,124,000
Costs capitalized subsequent to acquisition	33,000
Gross amount at which carried at close of period [Abstract]
Land	66,000
Buildings & Improvements	2,157,000
Total	2,223,000
Accumulated Depreciation	(165,000)
Year of Construction or Acquisition	2011
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	2,223,000
Deductions during year [Abstract]
Balance at close of year	165,000
Commercial Healthcare [Member] | Spring Creek-Ustick - Meridian, ID [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	467,000
Buildings & Improvements	3,833,000
Costs capitalized subsequent to acquisition	0
Gross amount at which carried at close of period [Abstract]
Land	467,000
Buildings & Improvements	3,833,000
Total	4,300,000
Accumulated Depreciation	(268,000)
Year of Construction or Acquisition	2011
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	4,300,000
Deductions during year [Abstract]
Balance at close of year	268,000
Commercial Healthcare [Member] | St Michael Clinic - St Michael, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	1,851,000
Initial Cost to Company [Abstract]
Land	328,000
Buildings & Improvements	2,259,000
Costs capitalized subsequent to acquisition	264,000
Gross amount at which carried at close of period [Abstract]
Land	328,000
Buildings & Improvements	2,523,000
Total	2,851,000
Accumulated Depreciation	(447,000)
Year of Construction or Acquisition	2007
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	2,851,000
Deductions during year [Abstract]
Balance at close of year	447,000
Commercial Healthcare [Member] | Trinity at Plaza 16 - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	4,854,000
Initial Cost to Company [Abstract]
Land	568,000
Buildings & Improvements	9,009,000
Costs capitalized subsequent to acquisition	125,000
Gross amount at which carried at close of period [Abstract]
Land	674,000
Buildings & Improvements	9,028,000
Total	9,702,000
Accumulated Depreciation	(588,000)
Year of Construction or Acquisition	2011
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	9,702,000
Deductions during year [Abstract]
Balance at close of year	588,000
Commercial Healthcare [Member] | Wells Clinic - Hibbing, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	1,365,000
Initial Cost to Company [Abstract]
Land	162,000
Buildings & Improvements	2,497,000
Costs capitalized subsequent to acquisition	2,000
Gross amount at which carried at close of period [Abstract]
Land	162,000
Buildings & Improvements	2,499,000
Total	2,661,000
Accumulated Depreciation	(626,000)
Year of Construction or Acquisition	2004
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	2,661,000
Deductions during year [Abstract]
Balance at close of year	626,000
Commercial Healthcare [Member] | Wholly Owned Properties [Member]
Additions during year [Abstract]
Additions	18,005,000		11,122,000		47,408,000
Commercial-Industrial [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	13,780,000
Initial Cost to Company [Abstract]
Land	12,098,000
Buildings & Improvements	36,298,000
Costs capitalized subsequent to acquisition	6,979,000
Gross amount at which carried at close of period [Abstract]
Land	12,377,000
Buildings & Improvements	42,998,000
Total	55,375,000
Accumulated Depreciation	(10,198,000)
Deductions during year [Abstract]
Balance at close of year	55,375,000
Deductions during year [Abstract]
Balance at close of year	10,198,000
Commercial-Industrial [Member] | Bloomington 2000 W 94th Street - Bloomington, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	2,133,000
Buildings & Improvements	4,097,000
Costs capitalized subsequent to acquisition	1,200,000
Gross amount at which carried at close of period [Abstract]
Land	2,187,000
Buildings & Improvements	5,243,000
Total	7,430,000
Accumulated Depreciation	(1,197,000)
Year of Construction or Acquisition	2006
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	7,430,000
Deductions during year [Abstract]
Balance at close of year	1,197,000
Commercial-Industrial [Member] | Eagan 2785 & 2795 Highway 55 - Eagan, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	3,058,000
Buildings & Improvements	2,570,000
Costs capitalized subsequent to acquisition	20,000
Gross amount at which carried at close of period [Abstract]
Land	3,058,000
Buildings & Improvements	2,590,000
Total	5,648,000
Accumulated Depreciation	(401,000)
Year of Construction or Acquisition	2008
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	5,648,000
Deductions during year [Abstract]
Balance at close of year	401,000
Commercial-Industrial [Member] | Lexington Commerce Center - Eagan, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	2,294,000
Initial Cost to Company [Abstract]
Land	453,000
Buildings & Improvements	4,352,000
Costs capitalized subsequent to acquisition	1,982,000
Gross amount at which carried at close of period [Abstract]
Land	480,000
Buildings & Improvements	6,307,000
Total	6,787,000
Accumulated Depreciation	(2,639,000)
Year of Construction or Acquisition	1999
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	6,787,000
Deductions during year [Abstract]
Balance at close of year	2,639,000
Commercial-Industrial [Member] | Minot IPS - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	416,000
Buildings & Improvements	5,635,000
Costs capitalized subsequent to acquisition	0
Gross amount at which carried at close of period [Abstract]
Land	416,000
Buildings & Improvements	5,635,000
Total	6,051,000
Accumulated Depreciation	(212,000)
Year of Construction or Acquisition	2012
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	6,051,000
Deductions during year [Abstract]
Balance at close of year	212,000
Commercial-Industrial [Member] | Stone Container - Fargo, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	922,000
Initial Cost to Company [Abstract]
Land	440,000
Buildings & Improvements	6,597,000
Costs capitalized subsequent to acquisition	104,000
Gross amount at which carried at close of period [Abstract]
Land	440,000
Buildings & Improvements	6,701,000
Total	7,141,000
Accumulated Depreciation	(2,776,000)
Year of Construction or Acquisition	2001
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	7,141,000
Deductions during year [Abstract]
Balance at close of year	2,776,000
Commercial-Industrial [Member] | Roseville 3075 Long Lake Road - Roseville, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	810,000
Buildings & Improvements	526,000
Costs capitalized subsequent to acquisition	106,000
Gross amount at which carried at close of period [Abstract]
Land	810,000
Buildings & Improvements	632,000
Total	1,442,000
Accumulated Depreciation	(4,000)
Year of Construction or Acquisition	2001
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	1,442,000
Deductions during year [Abstract]
Balance at close of year	4,000
Commercial-Industrial [Member] | Urbandale 3900 106th Street - Urbandale, IA [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	10,564,000
Initial Cost to Company [Abstract]
Land	3,680,000
Buildings & Improvements	9,893,000
Costs capitalized subsequent to acquisition	1,683,000
Gross amount at which carried at close of period [Abstract]
Land	3,863,000
Buildings & Improvements	11,393,000
Total	15,256,000
Accumulated Depreciation	(2,135,000)
Year of Construction or Acquisition	2007
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	15,256,000
Deductions during year [Abstract]
Balance at close of year	2,135,000
Commercial-Industrial [Member] | Woodbury 1865 Woodlane - Woodbury, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	1,108,000
Buildings & Improvements	2,628,000
Costs capitalized subsequent to acquisition	1,884,000
Gross amount at which carried at close of period [Abstract]
Land	1,123,000
Buildings & Improvements	4,497,000
Total	5,620,000
Accumulated Depreciation	(834,000)
Year of Construction or Acquisition	2007
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	5,620,000
Deductions during year [Abstract]
Balance at close of year	834,000
Commercial-Industrial [Member] | Wholly Owned Properties [Member]
Additions during year [Abstract]
Additions	0		5,900,000		0
Commercial Retail [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	26,621,000
Initial Cost to Company [Abstract]
Land	16,924,000
Buildings & Improvements	78,702,000
Costs capitalized subsequent to acquisition	21,643,000
Gross amount at which carried at close of period [Abstract]
Land	19,097,000
Buildings & Improvements	98,172,000
Total	117,269,000
Accumulated Depreciation	(28,255,000)
Deductions during year [Abstract]
Balance at close of year	117,269,000
Deductions during year [Abstract]
Balance at close of year	28,255,000
Commercial Retail [Member] | 17 South Main - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	78,000
Initial Cost to Company [Abstract]
Land	15,000
Buildings & Improvements	75,000
Costs capitalized subsequent to acquisition	197,000
Gross amount at which carried at close of period [Abstract]
Land	17,000
Buildings & Improvements	270,000
Total	287,000
Accumulated Depreciation	(199,000)
Year of Construction or Acquisition	2000
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	287,000
Deductions during year [Abstract]
Balance at close of year	199,000
Commercial Retail [Member] | Arrowhead First International Bank - Minot ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	75,000
Buildings & Improvements	1,211,000
Costs capitalized subsequent to acquisition	20,000
Gross amount at which carried at close of period [Abstract]
Land	95,000
Buildings & Improvements	1,211,000
Total	1,306,000
Accumulated Depreciation	(34,000)
Year of Construction or Acquisition	2013
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	1,306,000
Deductions during year [Abstract]
Balance at close of year	34,000
Commercial Retail [Member] | Burnsville 1 Strip Center - Burnsville, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	208,000
Buildings & Improvements	773,000
Costs capitalized subsequent to acquisition	205,000
Gross amount at which carried at close of period [Abstract]
Land	208,000
Buildings & Improvements	978,000
Total	1,186,000
Accumulated Depreciation	(284,000)
Year of Construction or Acquisition	2003
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	1,186,000
Deductions during year [Abstract]
Balance at close of year	284,000
Commercial Retail [Member] | Champlin South Pond - Champlin, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	1,332,000
Initial Cost to Company [Abstract]
Land	842,000
Buildings & Improvements	2,703,000
Costs capitalized subsequent to acquisition	95,000
Gross amount at which carried at close of period [Abstract]
Land	866,000
Buildings & Improvements	2,774,000
Total	3,640,000
Accumulated Depreciation	(722,000)
Year of Construction or Acquisition	2004
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	3,640,000
Deductions during year [Abstract]
Balance at close of year	722,000
Commercial Retail [Member] | Chan West Village - Chanhassen, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	12,690,000
Initial Cost to Company [Abstract]
Land	5,035,000
Buildings & Improvements	14,665,000
Costs capitalized subsequent to acquisition	2,025,000
Gross amount at which carried at close of period [Abstract]
Land	5,624,000
Buildings & Improvements	16,101,000
Total	21,725,000
Accumulated Depreciation	(4,760,000)
Year of Construction or Acquisition	2003
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	21,725,000
Deductions during year [Abstract]
Balance at close of year	4,760,000
Commercial Retail [Member] | Dakota West Plaza - Minot , ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	356,000
Initial Cost to Company [Abstract]
Land	92,000
Buildings & Improvements	493,000
Costs capitalized subsequent to acquisition	30,000
Gross amount at which carried at close of period [Abstract]
Land	106,000
Buildings & Improvements	509,000
Total	615,000
Accumulated Depreciation	(108,000)
Year of Construction or Acquisition	2006
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	615,000
Deductions during year [Abstract]
Balance at close of year	108,000
Commercial Retail [Member] | Duluth 4615 Grand - Duluth, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	612,000
Initial Cost to Company [Abstract]
Land	130,000
Buildings & Improvements	1,800,000
Costs capitalized subsequent to acquisition	4,000
Gross amount at which carried at close of period [Abstract]
Land	131,000
Buildings & Improvements	1,803,000
Total	1,934,000
Accumulated Depreciation	(453,000)
Year of Construction or Acquisition	2004
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	1,934,000
Deductions during year [Abstract]
Balance at close of year	453,000
Commercial Retail [Member] | Duluth Denfeld Retail - Duluth, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	2,023,000
Initial Cost to Company [Abstract]
Land	276,000
Buildings & Improvements	4,699,000
Costs capitalized subsequent to acquisition	162,000
Gross amount at which carried at close of period [Abstract]
Land	297,000
Buildings & Improvements	4,840,000
Total	5,137,000
Accumulated Depreciation	(1,256,000)
Year of Construction or Acquisition	2004
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	5,137,000
Deductions during year [Abstract]
Balance at close of year	1,256,000
Commercial Retail [Member] | Fargo Express Community - Fargo, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	882,000
Initial Cost to Company [Abstract]
Land	374,000
Buildings & Improvements	1,420,000
Costs capitalized subsequent to acquisition	777,000
Gross amount at which carried at close of period [Abstract]
Land	386,000
Buildings & Improvements	2,185,000
Total	2,571,000
Accumulated Depreciation	(507,000)
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	2,571,000
Deductions during year [Abstract]
Balance at close of year	507,000
Commercial Retail [Member] | Fargo Express Community - Fargo, ND [Member] | Minimum [Member]
Gross amount at which carried at close of period [Abstract]
Life on which depreciation in latest income statement is computed	2003 years
Commercial Retail [Member] | Fargo Express Community - Fargo, ND [Member] | Maximum [Member]
Gross amount at which carried at close of period [Abstract]
Life on which depreciation in latest income statement is computed	2005 years
Commercial Retail [Member] | Forest Lake Auto - Forest Lake, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	50,000
Buildings & Improvements	446,000
Costs capitalized subsequent to acquisition	13,000
Gross amount at which carried at close of period [Abstract]
Land	50,000
Buildings & Improvements	459,000
Total	509,000
Accumulated Depreciation	(132,000)
Year of Construction or Acquisition	2003
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	509,000
Deductions during year [Abstract]
Balance at close of year	132,000
Commercial Retail [Member] | Forest Lake Westlake Center - Forest Lake, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	2,446,000
Buildings & Improvements	5,304,000
Costs capitalized subsequent to acquisition	1,099,000
Gross amount at which carried at close of period [Abstract]
Land	2,480,000
Buildings & Improvements	6,369,000
Total	8,849,000
Accumulated Depreciation	(1,651,000)
Year of Construction or Acquisition	2003
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	8,849,000
Deductions during year [Abstract]
Balance at close of year	1,651,000
Commercial Retail [Member] | Grand Forks Carmike - Grand Forks, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	1,426,000
Initial Cost to Company [Abstract]
Land	184,000
Buildings & Improvements	2,360,000
Costs capitalized subsequent to acquisition	2,000
Gross amount at which carried at close of period [Abstract]
Land	184,000
Buildings & Improvements	2,362,000
Total	2,546,000
Accumulated Depreciation	(1,152,000)
Year of Construction or Acquisition	1994
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	2,546,000
Deductions during year [Abstract]
Balance at close of year	1,152,000
Commercial Retail [Member] | Grand Forks Medpark Mall - Grand Forks, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	681,000
Buildings & Improvements	4,808,000
Costs capitalized subsequent to acquisition	231,000
Gross amount at which carried at close of period [Abstract]
Land	722,000
Buildings & Improvements	4,998,000
Total	5,720,000
Accumulated Depreciation	(1,800,000)
Year of Construction or Acquisition	2000
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	5,720,000
Deductions during year [Abstract]
Balance at close of year	1,800,000
Commercial Retail [Member] | Jamestown Buffalo Mall - Jamestown, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	1,934,000
Initial Cost to Company [Abstract]
Land	566,000
Buildings & Improvements	5,551,000
Costs capitalized subsequent to acquisition	2,848,000
Gross amount at which carried at close of period [Abstract]
Land	1,114,000
Buildings & Improvements	7,851,000
Total	8,965,000
Accumulated Depreciation	(1,746,000)
Year of Construction or Acquisition	2003
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	8,965,000
Deductions during year [Abstract]
Balance at close of year	1,746,000
Commercial Retail [Member] | Jamestown Business Center - Jamestown, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	399,000
Initial Cost to Company [Abstract]
Land	297,000
Buildings & Improvements	1,023,000
Costs capitalized subsequent to acquisition	1,330,000
Gross amount at which carried at close of period [Abstract]
Land	333,000
Buildings & Improvements	2,317,000
Total	2,650,000
Accumulated Depreciation	(930,000)
Year of Construction or Acquisition	2003
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	2,650,000
Deductions during year [Abstract]
Balance at close of year	930,000
Commercial Retail [Member] | Kalispell Retail Center - Kalispell, MT [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	971,000
Initial Cost to Company [Abstract]
Land	250,000
Buildings & Improvements	2,250,000
Costs capitalized subsequent to acquisition	973,000
Gross amount at which carried at close of period [Abstract]
Land	253,000
Buildings & Improvements	3,220,000
Total	3,473,000
Accumulated Depreciation	(840,000)
Year of Construction or Acquisition	2003
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	3,473,000
Deductions during year [Abstract]
Balance at close of year	840,000
Commercial Retail [Member] | Lakeville Strip Center - Lakeville, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	874,000
Initial Cost to Company [Abstract]
Land	46,000
Buildings & Improvements	1,142,000
Costs capitalized subsequent to acquisition	852,000
Gross amount at which carried at close of period [Abstract]
Land	94,000
Buildings & Improvements	1,946,000
Total	2,040,000
Accumulated Depreciation	(667,000)
Year of Construction or Acquisition	2003
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	2,040,000
Deductions during year [Abstract]
Balance at close of year	667,000
Commercial Retail [Member] | Minot Arrowhead - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	100,000
Buildings & Improvements	3,216,000
Costs capitalized subsequent to acquisition	5,462,000
Gross amount at which carried at close of period [Abstract]
Land	116,000
Buildings & Improvements	8,662,000
Total	8,778,000
Accumulated Depreciation	(1,718,000)
Year of Construction or Acquisition	1973
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	8,778,000
Deductions during year [Abstract]
Balance at close of year	1,718,000
Commercial Retail [Member] | Minot Plaza - Minot, ND [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	777,000
Initial Cost to Company [Abstract]
Land	50,000
Buildings & Improvements	453,000
Costs capitalized subsequent to acquisition	147,000
Gross amount at which carried at close of period [Abstract]
Land	80,000
Buildings & Improvements	570,000
Total	650,000
Accumulated Depreciation	(317,000)
Year of Construction or Acquisition	1993
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	650,000
Deductions during year [Abstract]
Balance at close of year	317,000
Commercial Retail [Member] | Monticello C Store - Monticello, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	65,000
Buildings & Improvements	770,000
Costs capitalized subsequent to acquisition	37,000
Gross amount at which carried at close of period [Abstract]
Land	97,000
Buildings & Improvements	775,000
Total	872,000
Accumulated Depreciation	(227,000)
Year of Construction or Acquisition	2003
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	872,000
Deductions during year [Abstract]
Balance at close of year	227,000
Commercial Retail [Member] | Omaha Barnes & Noble - Omaha, NE [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	2,267,000
Initial Cost to Company [Abstract]
Land	600,000
Buildings & Improvements	3,099,000
Costs capitalized subsequent to acquisition	0
Gross amount at which carried at close of period [Abstract]
Land	600,000
Buildings & Improvements	3,099,000
Total	3,699,000
Accumulated Depreciation	(1,433,000)
Year of Construction or Acquisition	1995
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	3,699,000
Deductions during year [Abstract]
Balance at close of year	1,433,000
Commercial Retail [Member] | Pine City C-Store - Pine City, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	83,000
Buildings & Improvements	357,000
Costs capitalized subsequent to acquisition	12,000
Gross amount at which carried at close of period [Abstract]
Land	83,000
Buildings & Improvements	369,000
Total	452,000
Accumulated Depreciation	(107,000)
Year of Construction or Acquisition	2003
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	452,000
Deductions during year [Abstract]
Balance at close of year	107,000
Commercial Retail [Member] | Pine City Evergreen Square - Pine City, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	154,000
Buildings & Improvements	2,646,000
Costs capitalized subsequent to acquisition	597,000
Gross amount at which carried at close of period [Abstract]
Land	385,000
Buildings & Improvements	3,012,000
Total	3,397,000
Accumulated Depreciation	(983,000)
Year of Construction or Acquisition	2003
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	3,397,000
Deductions during year [Abstract]
Balance at close of year	983,000
Commercial Retail [Member] | Rochester Maplewood Square - Rochester, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	3,275,000
Buildings & Improvements	8,610,000
Costs capitalized subsequent to acquisition	2,089,000
Gross amount at which carried at close of period [Abstract]
Land	3,652,000
Buildings & Improvements	10,322,000
Total	13,974,000
Accumulated Depreciation	(3,581,000)
Year of Construction or Acquisition	1999
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	13,974,000
Deductions during year [Abstract]
Balance at close of year	3,581,000
Commercial Retail [Member] | St. Cloud Westgate - St. Cloud, MN [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	885,000
Buildings & Improvements	5,535,000
Costs capitalized subsequent to acquisition	1,738,000
Gross amount at which carried at close of period [Abstract]
Land	977,000
Buildings & Improvements	7,181,000
Total	8,158,000
Accumulated Depreciation	(1,729,000)
Year of Construction or Acquisition	2004
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	8,158,000
Deductions during year [Abstract]
Balance at close of year	1,729,000
Commercial Retail [Member] | Weston Retail - Weston, WI [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	79,000
Buildings & Improvements	1,575,000
Costs capitalized subsequent to acquisition	27,000
Gross amount at which carried at close of period [Abstract]
Land	80,000
Buildings & Improvements	1,601,000
Total	1,681,000
Accumulated Depreciation	(448,000)
Year of Construction or Acquisition	2003
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	1,681,000
Deductions during year [Abstract]
Balance at close of year	448,000
Commercial Retail [Member] | Weston Walgreens - Weston, WI [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	0
Initial Cost to Company [Abstract]
Land	66,000
Buildings & Improvements	1,718,000
Costs capitalized subsequent to acquisition	671,000
Gross amount at which carried at close of period [Abstract]
Land	67,000
Buildings & Improvements	2,388,000
Total	2,455,000
Accumulated Depreciation	(471,000)
Year of Construction or Acquisition	2006
Life on which depreciation in latest income statement is computed	40 years
Deductions during year [Abstract]
Balance at close of year	2,455,000
Deductions during year [Abstract]
Balance at close of year	471,000
Commercial Retail [Member] | Wholly Owned Properties [Member]
Additions during year [Abstract]
Additions	0		1,240,000		2,316,000
Subtotal [Member]
Real Estate And Accumulated Depreciation [Abstract]
Encumbrances	997,689,000
Initial Cost to Company [Abstract]
Land	185,371,000
Buildings & Improvements	1,541,588,000
Costs capitalized subsequent to acquisition	269,072,000
Gross amount at which carried at close of period [Abstract]
Land	205,017,000
Buildings & Improvements	1,791,014,000
Total	1,996,031,000
Accumulated Depreciation	(424,288,000)
Deductions during year [Abstract]
Balance at close of year	1,996,031,000
Deductions during year [Abstract]
Balance at close of year	$ 424,288,000

[1] The net basis of the Company’s real estate investments for Federal Income Tax purposes was approximately $1.5 billion, $1.5 billion and $1.4 billion at April 30, 2014, 2013 and 2012, respectively.

[2] (as revised)

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

[4] Consists of miscellaneous re-classed assets.

[5] Consists of miscellaneous disposed assets.