Mortgage Notes Payable (Details) (USD $)	9 Months Ended
	Sep. 30, 2012	Dec. 31, 2011
Schedule of Mortgage notes payable
Principal Balance	$ 202,287,592	$ 217,479,862
Auburn II (Arneson) Maturing on October -17 [Member]
Schedule of Mortgage notes payable
Maturity Date	October-17
Interest Rate Per Annum	6.30%
Principal Balance	638,279	645,938
Hunter's Run I (Arneson) Maturing on 0ctober-17 [Member]
Schedule of Mortgage notes payable
Maturity Date	October-17
Interest Rate Per Annum	6.30%
Principal Balance	306,982	310,665
Autumn Ridge 3 &4 Maturing on July-16 [Member]
Schedule of Mortgage notes payable
Maturity Date	July-16
Interest Rate Per Annum	4.50%
Principal Balance	3,467,019	3,551,730
Autumn Ridge 1 & 2 Maturing on January-16 [Member]
Schedule of Mortgage notes payable
Maturity Date	January-16
Interest Rate Per Annum	5.74%
Principal Balance	2,940,485	2,981,073
Bayview Maturing on December-13 [Member]
Schedule of Mortgage notes payable
Maturity Date	December-13
Interest Rate Per Annum	6.73%
Principal Balance	2,049,872	2,100,796
Berkshire Maturing on June-18 [Member]
Schedule of Mortgage notes payable
Maturity Date	June-18
Interest Rate Per Annum	5.25%
Principal Balance	330,301	337,723
Brookfield Maturing on September-21 [Member]
Schedule of Mortgage notes payable
Maturity Date	September-21
Interest Rate Per Annum	3.75%
Principal Balance	1,551,590	1,657,972
Carling Manor Maturing on September-36 [Member]
Schedule of Mortgage notes payable
Maturity Date	September-36
Interest Rate Per Annum	4.40%
Principal Balance	554,993	564,533
Carlton 1-3 Maturing on December-13 [Member]
Schedule of Mortgage notes payable
Maturity Date	December-13
Interest Rate Per Annum	5.60%
Principal Balance	2,202,579	2,241,563
Carlton Place Maturing on June-13 [Member]
Schedule of Mortgage notes payable
Maturity Date	June-13
Interest Rate Per Annum	6.96%
Principal Balance	1,936,723	1,986,250
Colony Manor Maturing on January-16 [Member]
Schedule of Mortgage notes payable
Maturity Date	January-16
Interest Rate Per Annum	5.96%
Principal Balance		869,372
Colony Manor Maturing on February-17 [Member]
Schedule of Mortgage notes payable
Maturity Date	February-17
Interest Rate Per Annum	3.63%
Principal Balance	860,903
Columbia West Maturing on September-14 [Member]
Schedule of Mortgage notes payable
Maturity Date	September-14
Interest Rate Per Annum	7.80%
Principal Balance	1,456,992	1,487,005
Country Club Maturing on November-24 [Member]
Schedule of Mortgage notes payable
Maturity Date	November-24
Interest Rate Per Annum	4.37%
Principal Balance	674,032	705,271
Danbury Maturing on October-19 [Member]
Schedule of Mortgage notes payable
Maturity Date	October-19
Interest Rate Per Annum	5.03%
Principal Balance	3,129,953	3,182,862
Eagle Run Maturing On March-17 [Member]
Schedule of Mortgage notes payable
Maturity Date	March-17
Interest Rate Per Annum	3.95%
Principal Balance	4,868,768	4,955,117
Emerald Court Maturing on June-18 [Member]
Schedule of Mortgage notes payable
Maturity Date	June-18
Interest Rate Per Annum	5.25%
Principal Balance	675,636	690,771
Fairview Maturing on March-17 [Member]
Schedule of Mortgage notes payable
Maturity Date	March-17
Interest Rate Per Annum	3.95%
Principal Balance	3,341,952	3,386,596
Flickertail Maturing on June-13 [Member]
Schedule of Mortgage notes payable
Maturity Date	June-13
Interest Rate Per Annum	6.96%
Principal Balance	2,848,125	2,920,958
Galleria III Maturing on December-17 [Member]
Schedule of Mortgage notes payable
Maturity Date	December-17
Interest Rate Per Annum	4.75%
Principal Balance	649,578	660,752
Glen Pond Maturing on August-16 [Member]
Schedule of Mortgage notes payable
Maturity Date	August-16
Interest Rate Per Annum	6.30%
Principal Balance	16,478,712	16,694,344
Hunter Maturing on March-17 [Member]
Schedule of Mortgage notes payable
Maturity Date	March-17
Interest Rate Per Annum	3.95%
Principal Balance	1,244,538	1,266,694
Islander Maturing on September-14 [Member]
Schedule of Mortgage notes payable
Maturity Date	September-14
Interest Rate Per Annum	6.00%
Principal Balance	510,109	522,787
Library Lane Maturing on December-17 [Member]
Schedule of Mortgage notes payable
Maturity Date	December-17
Interest Rate Per Annum	6.10%
Principal Balance	1,957,780	1,981,723
Maple Ridge Maturing on May-21 [Member]
Schedule of Mortgage notes payable
Maturity Date	May-21
Interest Rate Per Annum	5.69%
Principal Balance	4,427,791	4,469,145
Maplewood Bend Maturing on March-17 [Member]
Schedule of Mortgage notes payable
Maturity Date	March-17
Interest Rate Per Annum	3.95%
Principal Balance	3,535,403	3,597,985
Oak Court Maturing on September-17 [Member]
Schedule of Mortgage notes payable
Maturity Date	September-17
Interest Rate Per Annum	5.98%
Principal Balance	1,899,516	1,919,916
Parkwood Maturing on October-15 [Member]
Schedule of Mortgage notes payable
Maturity Date	October-15
Interest Rate Per Annum	5.96%
Principal Balance		977,791
Parkwood Maturing on February-17 [Member]
Schedule of Mortgage notes payable
Maturity Date	February-17
Interest Rate Per Annum	3.63%
Principal Balance	1,264,878
Pebble Creek Maturing on January-13 [Member]
Schedule of Mortgage notes payable
Maturity Date	January-13
Interest Rate Per Annum	5.72%
Principal Balance	2,547,087	2,595,793
Prairiewood Courts Maturing on June-18 [Member]
Schedule of Mortgage notes payable
Maturity Date	June-18
Interest Rate Per Annum	5.25%
Principal Balance	1,632,406	1,668,991
Prairiewood Meadows Maturing on October-20 [Member]
Schedule of Mortgage notes payable
Maturity Date	October-20
Interest Rate Per Annum	6.17%
Principal Balance	2,435,869
Richfield/Harrison Maturing on December-13 [Member]
Schedule of Mortgage notes payable
Maturity Date	December-13
Interest Rate Per Annum	6.67%
Principal Balance	2,599,833	2,664,804
Rosegate Maturing on September-17 [Member]
Schedule of Mortgage notes payable
Maturity Date	September-17
Interest Rate Per Annum	5.93%
Principal Balance	2,420,609	2,446,864
Saddlebrook Maturing on September-36 [Member]
Schedule of Mortgage notes payable
Maturity Date	September-36
Interest Rate Per Annum	4.40%
Principal Balance	1,141,669	1,161,291
Sierra Ridge Phase I Maturing on August-19 [Member]
Schedule of Mortgage notes payable
Maturity Date	August-19
Interest Rate Per Annum	5.46%
Principal Balance	2,746,181	2,790,426
Sierra Ridge Phase II Maturing on November-19 [Member]
Schedule of Mortgage notes payable
Maturity Date	November-19
Interest Rate Per Annum	5.92%
Principal Balance	3,444,619	3,491,138
Somerset Maturing on December-12 [Member]
Schedule of Mortgage notes payable
Maturity Date	December-12
Interest Rate Per Annum	5.60%
Principal Balance		1,889,144
Southgate Maturing on July-21 [Member]
Schedule of Mortgage notes payable
Maturity Date	July-21
Interest Rate Per Annum	5.96%
Principal Balance	3,095,884	3,139,094
Southview III Maturing on August-16 [Member]
Schedule of Mortgage notes payable
Maturity Date	August-16
Interest Rate Per Annum	4.50%
Principal Balance	243,449	247,617
Southview Villages Maturing on December-17 [Member]
Schedule of Mortgage notes payable
Maturity Date	December-17
Interest Rate Per Annum	6.10%
Principal Balance	2,140,226	2,166,400
Stonybrook Maturing on April-15 [Member]
Schedule of Mortgage notes payable
Maturity Date	April-15
Interest Rate Per Annum	5.40%
Principal Balance	5,710,409	5,786,446
Sunset Ridge Maturing on January-22 [Member]
Schedule of Mortgage notes payable
Maturity Date	January-22
Interest Rate Per Annum	4.44%
Principal Balance	9,337,876	9,435,000
Sunview Maturing on May-19 [Member]
Schedule of Mortgage notes payable
Maturity Date	May-19
Interest Rate Per Annum	5.75%
Principal Balance	1,268,264	1,289,752
Sunwood Estates Maturing on January-13 [Member]
Schedule of Mortgage notes payable
Maturity Date	January-13
Interest Rate Per Annum	7.18%
Principal Balance		1,858,047
Terrace on the Green Maturing on June-19 [Member]
Schedule of Mortgage notes payable
Maturity Date	June-19
Interest Rate Per Annum	6.53%
Principal Balance	2,196,837
Twin Parks Maturing on March-14 [Member]
Schedule of Mortgage notes payable
Maturity Date	March-14
Interest Rate Per Annum	5.75%
Principal Balance		1,660,966
Village Maturing on May-19 [Member]
Schedule of Mortgage notes payable
Maturity Date	May-19
Interest Rate Per Annum	5.75%
Principal Balance	1,119,023	1,137,984
Village Park Maturing on July-16 [Member]
Schedule of Mortgage notes payable
Maturity Date	July-16
Interest Rate Per Annum	6.15%
Principal Balance	917,180	936,141
Westwind Maturing on June-18 [Member]
Schedule of Mortgage notes payable
Maturity Date	June-18
Interest Rate Per Annum	5.25%
Principal Balance	375,751	384,163
Westwood Maturing on March-17 [Member]
Schedule of Mortgage notes payable
Maturity Date	March-17
Interest Rate Per Annum	3.95%
Principal Balance	5,279,631	5,409,723
Willow Park Maturing on July-13 [Member]
Schedule of Mortgage notes payable
Maturity Date	July-13
Interest Rate Per Annum	6.96%
Principal Balance	2,551,722	2,616,412
EV-Bismarck Maturing on June-15 [Member]
Schedule of Mortgage notes payable
Maturity Date	June-15
Interest Rate Per Annum	5.64%
Principal Balance	15,051,113	15,327,299
Guardian Building Products Maturing on September-17 [Member]
Schedule of Mortgage notes payable
Maturity Date	September-17
Interest Rate Per Annum	3.45%
Principal Balance	2,415,000
Titan Machinery - Dickinson, ND Maturing on November-16 [Member]
Schedule of Mortgage notes payable
Maturity Date	November-16
Interest Rate Per Annum	4.23%
Principal Balance	423,719
Titan Machinery - Marshall, MN Maturing on January-17 [Member]
Schedule of Mortgage notes payable
Maturity Date	January-17
Interest Rate Per Annum	4.55%
Principal Balance	2,385,871	2,445,391
Titan Machinery - Minot, ND Maturing on August-17 [Member]
Schedule of Mortgage notes payable
Maturity Date	August-17
Interest Rate Per Annum	3.29%
Principal Balance	1,833,863
Bio-life Properties - ND, MN, WI (9 total) Maturing on March-16 [Member]
Schedule of Mortgage notes payable
Maturity Date	March-16
Interest Rate Per Annum	7.56%
Principal Balance	10,199,470	10,942,103
Bio-life Properties - Marquette, MI Maturing on December-16 [Member]
Schedule of Mortgage notes payable
Maturity Date	December-16
Interest Rate Per Annum	7.06%
Principal Balance	1,458,742	1,566,954
Aetna Maturing on August-17 [Member]
Schedule of Mortgage notes payable
Maturity Date	August-17
Interest Rate Per Annum	5.93%
Principal Balance	7,095,207	7,178,722
Banner Building Maturing on August-22 [Member]
Schedule of Mortgage notes payable
Maturity Date	August-22
Interest Rate Per Annum	7.04%
Principal Balance		5,052,762
CFB Maturing on December-13 [Member]
Schedule of Mortgage notes payable
Maturity Date	December-13
Interest Rate Per Annum	4.00%
Principal Balance	2,356,988	2,401,144
Echelon Maturing on February-15 [Member]
Schedule of Mortgage notes payable
Maturity Date	February-15
Interest Rate Per Annum	4.25%
Principal Balance	1,238,693	1,286,104
Gate City Maturing on April-18 [Member]
Schedule of Mortgage notes payable
Maturity Date	April-18
Interest Rate Per Annum	3.97%
Principal Balance	1,093,396	1,114,788
Goldmark Office Park Maturing on September-20 [Member]
Schedule of Mortgage notes payable
Maturity Date	September-20
Interest Rate Per Annum	5.33%
Principal Balance	5,358,848	5,753,990
Grand Forks Marketplace Maturing on August-13 [Member]
Schedule of Mortgage notes payable
Maturity Date	August-13
Interest Rate Per Annum	5.26%
Principal Balance		5,974,655
Great American Building Maturing on April-20 [Member]
Schedule of Mortgage notes payable
Maturity Date	April-20
Interest Rate Per Annum	7.25%
Principal Balance	1,113,412	1,136,368
Midtown Plaza Maturing on April-16 [Member]
Schedule of Mortgage notes payable
Maturity Date	April-16
Interest Rate Per Annum	5.31%
Principal Balance		703,705
Regis Maturing on October-15 [Member]
Schedule of Mortgage notes payable
Maturity Date	October-15
Interest Rate Per Annum	5.68%
Principal Balance	9,791,386	9,938,892
Dairy Queen - Dickinson, ND Maturing on April-17 [Member]
Schedule of Mortgage notes payable
Maturity Date	April-17
Interest Rate Per Annum	3.63%
Principal Balance	758,719
Mandan Commercial Maturing on January-16 [Member]
Schedule of Mortgage notes payable
Maturity Date	January-16
Interest Rate Per Annum	5.25%
Principal Balance		1,087,056
Moorhead Commercial Maturing on December-12 [Member]
Schedule of Mortgage notes payable
Maturity Date	December-12
Interest Rate Per Annum	3.00%
Principal Balance		553,938
Walgreens-Alexandria Maturing on April-25 [Member]
Schedule of Mortgage notes payable
Maturity Date	April-25
Interest Rate Per Annum	5.69%
Principal Balance	2,256,439	2,346,633
Walgreens-Batesville Maturing on March-34 [Member]
Schedule of Mortgage notes payable
Maturity Date	March-34
Interest Rate Per Annum	6.85%
Principal Balance	6,636,586	6,735,726
Walgreens-Colorado Maturing on June-21 [Member]
Schedule of Mortgage notes payable
Maturity Date	June-21
Interest Rate Per Annum	4.50%
Principal Balance	4,473,278	4,549,718
Walgreens-Fayetteville Maturing on August-33 [Member]
Schedule of Mortgage notes payable
Maturity Date	August-33
Interest Rate Per Annum	6.85%
Principal Balance	5,105,129	5,185,468
Walgreens-Laurel Maturing on October-24 [Member]
Schedule of Mortgage notes payable
Maturity Date	October-24
Interest Rate Per Annum	6.07%
Principal Balance	2,233,718	2,321,749
Westpointe Center Maturing on December-13 [Member]
Schedule of Mortgage notes payable
Maturity Date	December-13
Interest Rate Per Annum	5.50%
Principal Balance		$ 2,433,166