SB Partners 10-K 30 Mar 21 2020 FY Annual report Financial data

Document And Entity Information

Document And Entity Information - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Jun. 30, 2020
Document Information [Line Items]
Entity Registrant Name	SB PARTNERS
Entity Central Index Key	0000087047
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Well-known Seasoned Issuer	No
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Interactive Data Current	Yes
Entity Common Stock, Shares Outstanding (in shares)	0
Entity Public Float		$ 0
Entity Shell Company	false
Document Type	10-K
Document Period End Date	Dec. 31, 2020
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Amendment Flag	false

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Assets:
Land	$ 470,000	$ 470,000
Buildings, furnishings and improvements	5,671,101	5,671,101
Less - accumulated depreciation	(2,559,959)	(2,395,451)
Real Estate Investment Property, Net, Total	3,581,142	3,745,650
Investment in Sentinel Omaha, LLC, net of reserve for fair value of $11,923,033 and $10,395,545 at December 31, 2020 and 2019, respectively	47,692,106	41,582,157
Investments, Total	51,273,248	45,327,807
Other Assets -
Cash and cash equivalents	549,195	987,624
Other	11,198	8,743
Total assets	51,833,641	46,324,174
Liabilities:
Accounts payable	154,636	177,596
Tenant security deposit	109,808	107,010
Total liabilities	264,444	284,606
Partners' Equity (Deficit):
Limited partner - 7,753 units	51,580,982	46,052,066
General partner - 1 unit	(11,785)	(12,498)
Total partners' equity	51,569,197	46,039,568
Total liabilities and partners' equity	$ 51,833,641	$ 46,324,174

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parentheticals) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Investment in Sentinel Omaha, LLC, reserve for fair value	$ 11,923,033	$ 10,395,545
Limited partner - units (in shares)	7,753	7,753
General partner - units (in shares)	1	1

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenues:
Rental income	$ 1,177,488	$ 1,126,745	$ 1,094,278
Interest income	2,230	4,739	16,178
Total revenues	1,179,718	1,131,484	1,110,456
Expenses:
Real estate operating expenses	312,558	304,542	304,672
Amortization of deferred financing costs			7,280
Depreciation	164,508	146,261	164,344
Real estate taxes	141,572	129,556	121,868
Management fees	1,018,617	1,007,137	911,615
Other	122,783	117,545	129,967
Total expenses	1,760,038	1,705,041	1,639,746
Loss from operations	(580,320)	(573,557)	(529,290)
Equity in net income of investment	7,637,437	6,829,088	5,842,182
(Increase) decrease in reserve for value of investment	(1,527,488)	314,179	1,816,884
Income from continuing operations	5,529,629	6,569,710	7,129,776
Gain on extinguishment of debt			1,693,876
Net income	5,529,629	6,569,710	8,823,652
Income allocated to general partner	713	847	1,138
Income allocated to limited partners	$ 5,528,916	$ 6,568,863	$ 8,822,514
Income per unit of limited partnership interest (basic and diluted)
Income from continuing operations (in dollars per share)	$ 713.22	$ 847.38	$ 919.62
Gain on extinguishment of debt (in dollars per share)			218.48
Net income (in dollars per share)	$ 713.22	$ 847.38	$ 1,138.10
Weighted Average Number of Units of Limited Partnership Interest Outstanding (in shares)	7,753	7,753	7,753

Consolidated Statements of Chan

Consolidated Statements of Changes in Partners' Equity (Deficit) - USD ($)	Limited Partner [Member]Units of Partnership [Member]	Limited Partner [Member]Cumulative Cash Distributions [Member]	Limited Partner [Member]Retained Earnings [Member]	Limited Partner [Member]	General Partner [Member]Units of Partnership [Member]	General Partner [Member]Cumulative Cash Distributions [Member]	General Partner [Member]Retained Earnings [Member]	General Partner [Member]	Total
Balance (in shares) at Dec. 31, 2017	7,753				1
Balance at Dec. 31, 2017	$ 119,968,973	$ (111,721,586)	$ 25,514,302	$ 33,761,689	$ 10,000	$ (26,364)	$ 2,281	$ (14,083)
Net increase in net assets			8,822,514	8,822,514			1,138	1,138	$ 8,823,652
Balance (in shares) at Dec. 31, 2018	7,753				1
Balance at Dec. 31, 2018	$ 119,968,973	(111,721,586)	34,336,816	42,584,203	$ 10,000	(26,364)	3,419	(12,945)
Net increase in net assets			6,568,863	6,568,863			847	847	6,569,710
Distribution paid		(3,101,000)		(3,101,000)		(400)		(400)
Balance (in shares) at Dec. 31, 2019	7,753				1
Balance at Dec. 31, 2019	$ 119,968,973	(114,822,586)	40,905,679	46,052,066	$ 10,000	(26,764)	4,266	(12,498)	46,039,568
Net increase in net assets			5,528,916	5,528,916			713	713	5,529,629
Balance (in shares) at Dec. 31, 2020	7,753				1
Balance at Dec. 31, 2020	$ 119,968,973	$ (114,822,586)	$ 46,434,595	$ 51,580,982	$ 10,000	$ (26,764)	$ 4,979	$ (11,785)	$ 51,569,197

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash Flows From Operating Activities:
Net income	$ 5,529,629	$ 6,569,710	$ 8,823,652
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Gain on extinguishment of debt			(1,693,876)
Equity in net (income) of investment	(7,637,437)	(6,829,088)	(5,842,182)
Increase (decrease) in reserve for value of investment	1,527,488	(314,179)	(1,816,884)
Depreciation and amortization	164,508	146,261	171,624
Net (increase) in other assets	(2,455)	(954)	(770)
Net (decrease) increase in accounts payable	(22,960)	(384,204)	45,007
Net increase in tenant security deposit	2,798	2,798	2,798
Net (decrease) increase in accrued expenses		(3,408,317)	485,374
Distributions from investment in Sentinel Omaha, LLC		8,400,000	2,400,000
Net cash provided by (used in) operating activities	(438,429)	4,182,027	2,574,742
Cash Flows From Investing Activities:
Capital additions to real estate owned		(431,242)	(158,494)
Net cash used in investing activities		(431,242)	(158,494)
Cash Flows From Financing Activities:
Distribution paid to partners		(3,101,400)
Repayment of loan payable			(4,032,714)
Net cash used in financing activities		(3,101,400)	(4,032,714)
Net change in cash and cash equivalents	(438,429)	649,385	(1,616,466)
Cash and cash equivalents at beginning of period	987,624	338,239	1,954,705
Cash and cash equivalents at end of period	$ 549,195	$ 987,624	$ 338,239

Note 1 - Organization and Signi

Note 1 - Organization and Significant Accounting Policies	12 Months Ended
	Dec. 31, 2020
Notes to Financial Statements
Organization, Consolidation and Presentation of Financial Statements Disclosure and Significant Accounting Policies [Text Block]	( 1 SB Partners, a New York limited partnership, and its subsidiaries (collectively, the "Partnership"), have been engaged since April 1971 The significant accounting and financial reporting policies of the Partnership are as follows: (a) The accompanying consolidated financial statements include the accounts of SB Partners and its subsidiaries. All significant intercompany accounts and transactions have been eliminated. The consolidated financial statements are prepared using the accrual basis of accounting in accordance with accounting principles generally accepted in the United States of America. The preparation of financial statements in conformity with such principles requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. (b) In connection with the mortgage financing on certain of its properties, the Partnership placed the assets and liabilities of the properties into single asset limited partnerships, limited liability companies or land trusts which hold title to the properties. The Partnership has effective control over such entities and holds 100% (c) Depreciation of buildings, furnishings and improvements is computed using the straight-line method of depreciation, based upon the estimated useful lives of the related properties, as follows: Buildings and Improvements (in years) 5 to 40 Furnishings (in years) 5 to 7 Investments in real estate are carried at historical cost and reviewed periodically for impairment. Expenditures for maintenance and repairs are expensed as incurred. Expenditures for improvements, renewals and betterments, which increase the useful life of the real estate, are capitalized. Upon retirement or sale of property, the related cost and accumulated depreciation are removed from the accounts. Amortization of deferred financing and refinancing costs is computed by amortizing the cost on a straight-line basis over the terms of the related mortgage notes. (d) Real estate properties are regularly evaluated on a property by property basis to determine if it is appropriate to write down carrying values to recognize an impairment of value. Impairment is determined by calculating the sum of the estimated undiscounted future cash flows including the projected undiscounted future net proceeds from the sale of the property. In the event such sum is less than the net carrying value of the property, the property will be written down to estimated fair value. Based on the Partnership's long-term hold strategy for its investments in real estate, the carrying value of its property at December 31, 2020 (e) Real estate held for sale is carried at the lower of cost or fair value less selling costs. Upon determination that a property is held for sale, depreciation of such property is no (f) For financial reporting purposes, the Partnership considers all highly liquid, short-term investments with original maturities of three not not (g) The Partnership accounts for its investment in Sentinel Omaha, LLC at fair value. Determination of the fair value of Omaha involves numerous estimates and subjective judgments that are subject to change in response to current and future economic and market conditions, including, among other things, demand for residential apartments, competition, and operating cost levels such as labor, energy costs and real estate taxes. Judgments regarding these factors are not may 6 7 (h) The Partnership has elected to classify distributions received from equity method investees using the cumulative earnings approach. Accordingly, distributions received from equity method investees are classified as cash inflows from operating activities on the accompanying Consolidated Statements of Cash Flows. (i) Tenant leases at the multifamily properties owned by Omaha generally have terms of one 3 (j) Sales of real estate owned are recognized in accordance with accounting principles generally accepted in the United States. Gains or losses on sales of real estate are recorded when a contract exists between buyer and seller, and whereby the entity transfers title. Net realized gain or loss on investments in real estate, if any, is the Company's share of cash proceeds from disposition of investments in real estate less the cost basis and transaction costs. (k) Each partner is individually responsible for reporting its share of the Partnership's taxable income or loss. Accordingly, no (l) Net income per unit of partnership interest has been computed based on the weighted average number of units of partnership interest outstanding during each year. There were no (m) The Partnership is engaged in only one not not

Note 2 - COVID-19

Note 2 - COVID-19	12 Months Ended
	Dec. 31, 2020
Notes to Financial Statements
Unusual or Infrequent Items, or Both, Disclosure [Text Block]	( 2 19 Due to the COVID- 19 may may no not December 31, 2020.

Note 3 - Common Area Maintenanc

Note 3 - Common Area Maintenance Reimbursements	12 Months Ended
	Dec. 31, 2020
Notes to Financial Statements
Revenue from Contract with Customer [Text Block]	( 3 In connection with the adoption of ASC Topic 842, 842, 606, Revenue from Contracts with Customers not The following table provides a disaggregation of rental income recognized by the Partnership for each of the three December 31, 2020: 2020 2019 2018 Operating lease income: Fixed lease income (Base Rent) $ 809,632 $ 772,617 $ 746,115 Variable lease income (Recoverable Costs) 367,856 354,128 348,163 Total Rental Income $ 1,177,488 $ 1,126,745 $ 1,094,278 Because the standard for lessors remained largely unchanged from the previous guidance, the adoption of ASC Topic 842 not

Note 4 - Investment Management

Note 4 - Investment Management Agreement	12 Months Ended
	Dec. 31, 2020
Notes to Financial Statements
Investment Management Agreement [Text Block]	( 4 The Partnership entered into a management agreement with the General Partner. Under the terms of this agreement, the General Partner is responsible for the acquisition, management and disposition of all investments, as well as performance of the day-to-day administrative operations and provision of office space for the Partnership. For these services, the General Partner receives a management fee equal to 2% 0.5% not $1,018,617, $1,007,137 $911,615 December 31, 2020, 2019, 2018, 2018, $485,375 2019 25% No December 31, 2020, 2019 2018.

Note 5 - Investments in Real Es

Note 5 - Investments in Real Estate	12 Months Ended
	Dec. 31, 2020
Notes to Financial Statements
Real Estate Disclosure [Text Block]	( 5 During 2020 2019 December 31, 2020 2019: Real Estate at Cost No. of Year of Type Prop. Acquisition Description 12/31/20 12/31/19 Industrial flex property 1 2002 60,345 sf $ 6,141,101 $ 6,141,101 Less: accumulated depreciation (2,559,959 ) (2,395,451 ) Net book value $ 3,581,142 $ 3,745,650

Note 6 - Assets Measured at Fai

Note 6 - Assets Measured at Fair Value	12 Months Ended
	Dec. 31, 2020
Notes to Financial Statements
Fair Value Measurement and Measurement Inputs, Recurring and Nonrecurring [Text Block]	( 6 The accounting guidance for Fair Value Measurements establishes a framework for measuring fair value that includes a hierarchy used to classify the inputs used in determining fair value. The hierarchy prioritizes the inputs to valuation techniques used to measure fair value into three Fair value is defined as the price that would be received upon sale of an asset or paid upon transfer of a liability in an orderly transaction between market participants at the measurement date and in the principal or most advantageous market for that asset or liability. The fair value is calculated based on the assumptions that market participants would use in pricing the asset or liability, not The three ● Level 1 ● Level 2 ● Level 3 The following major categories of assets were measured at fair value during the year ended December 31, 2020 2019: Level 3: Significant Unobservable 2020 Inputs Total Assets Investment in Sentinel Omaha, LLC $ 59,615,139 $ 59,615,139 Reserve for fair value of investment (11,923,033 ) (11,923,033 ) Total assets $ 47,692,106 $ 47,692,106 Level 3: Significant Unobservable 2019 Inputs Total Assets Investment in Sentinel Omaha, LLC $ 51,977,702 $ 51,977,702 Reserve for fair value of investment (10,395,545 ) (10,395,545 ) Total assets $ 41,582,157 $ 41,582,157 The following is a reconciliation of the beginning and ending balances for assets measured at fair value using significant unobservable inputs (Level 3 December 31, 2020 2019: Investment in Reserve for Sentinel fair value Omaha, LLC of investment Total Balance at January 1, 2019 $ 53,548,614 $ (10,709,724 ) $ 42,838,890 Equity in net income of investment 6,829,088 - 6,829,088 Distribution from investment (8,400,000 ) (8,400,000 ) Decrease in reserve - 314,179 314,179 Balance at December 31, 2019 51,977,702 (10,395,545 ) 41,582,157 Equity in net income of investment 7,637,437 - 7,637,437 Distribution from investment - - - Increase in reserve - (1,527,488 ) (1,527,488 ) Balance at December 31, 2020 $ 59,615,139 $ (11,923,033 ) $ 47,692,106 As of December 31, 2018 30% December 31, 2018 20% 30% 20% December 31, 2020. For the year ended December 31, 2020 3.8% 2020 2019. During 2020 may 2020 not may

Note 7 - Investment in Sentinel

Note 7 - Investment in Sentinel Omaha, LLC	12 Months Ended
	Dec. 31, 2020
Notes to Financial Statements
Equity Method Investments and Joint Ventures Disclosure [Text Block]	( 7 In 2007, $37,200,000 thirty December 31, 2020 five three 10 With respect to its investment in Omaha, the Partnership elected to adopt Accounting Standards Codification Topic 825. The following are the audited condensed financial statements ( 000's December 31, 2020 2019 three December 31, 2020: Balance Sheet 2020 2019 Investment in real estate properties, at fair value $ 190,600 $ 230,900 Other assets 61,315 19,825 Debt (49,880 ) (73,892 ) Other liabilities (3,318 ) (3,574 ) Members' equity $ 198,717 $ 173,259 Statement of Operations 2020 2019 2018 Rent and other income $ 24,239 $ 26,602 $ 33,786 Real estate operating expenses (12,090 ) (12,618 ) (16,189 ) Other expenses (1,563 ) (3,489 ) (5,705 ) Net unrealized (losses) gains (8,286 ) (1,366 ) 488 Net realized gain (losses) 23,158 13,635 7,094 Net increase in net assets $ 25,458 $ 22,764 $ 19,474 Determination of the fair value of Omaha involves numerous estimates and subjective judgments that are subject to change in response to current and future economic and market conditions, including, among other things, demand for residential apartments, competition, and operating cost levels such as labor, energy costs, real estate taxes and market interest rates. Judgments regarding these factors are not may Estimated fair value was determined utilizing Level 3 2 The investment in Omaha is not not The values of real estate properties have been prepared giving consideration to the income and sales comparison approaches of estimating property value. The income approach estimates an income stream for a property and discounts this income plus a reversion (presumed sale) into a present value at a risk adjusted rate. Yield rates and growth assumptions utilized in this approach are derived from market transactions as well as other financial and industry data. The sales comparison approach compares recent transactions to the appraised property. Adjustments are made for dissimilarities which typically provide a range of value. Generally, the income approach carries the most weight in the value reconciliation. Substantially all of Omaha's real estate properties are classified within Level 3 The mortgage notes payable are all variable rate loans at December 31, 2020; The following table shows quantitative information about significant unobservable inputs related to Level 3 December 31, 2020 ( 000's Fair Valuation Unobservable Range Value Techniques Inputs (Weighted Average) Investment in real estate properties $ 190,600 Discounted cash flows (DCF) Discount rate 7.12% - 7.75% (7.21%) Capitalization rate 4.75% - 5.50% (5.00%) DCF Term (years) 10

Note 8 - Quarterly Financial In

Note 8 - Quarterly Financial Information (Unaudited)	12 Months Ended
	Dec. 31, 2020
Notes to Financial Statements
Quarterly Financial Information [Text Block]	( 8 Revenues from Net Income (Loss) per Equity in Net Continuing Unit of Limited Income (Loss) Year ended December 31, 2020 Operations Net Income (Loss) Partnership Interest of Investment First Quarter $ 293,365 $ 250,359 $ 32.29 $ 484,477 Second Quarter 295,300 (491,128) (63.35) (442,722 ) Third Quarter 293,529 92,443 11.92 315,222 Fourth Quarter 297,524 5,677,955 732.36 7,280,460 Year ended December 31, 2019 First Quarter $ 278,356 $ 189,419 $ 24.43 $ 408,908 Second Quarter 278,993 2,159,145 278.49 795,927 Third Quarter 279,769 1,009,983 130.27 1,439,584 Fourth Quarter 294,366 3,211,163 414.19 4,184,669

Note 9 - Federal Income Tax Inf

Note 9 - Federal Income Tax Information (Unaudited)	12 Months Ended
	Dec. 31, 2020
Notes to Financial Statements
Income Tax Disclosure [Text Block]	( 9 A reconciliation of net income for financial reporting purposes to net income for Federal income tax reporting purposes is as follows: For the Years Ended December 31, 2020 2019 2018 Net income for financial reporting purposes $ 5,529,629 $ 6,569,710 $ 8,823,652 Difference between tax and financial statement equity in net income/ loss of investment 6,077,663 4,175,809 2,807,300 Difference between accrued investment management fees, mortgage interest and partnership administrative expenses recognized for tax purposes 0 (3,734,253 ) 525,375 Difference between tax and financial statement depreciation 8,251 8,712 13,429 Net income for Federal income tax reporting purposes $ 11,615,543 $ 7,019,978 $ 12,169,756 Net ordinary income (loss) for Federal income tax reporting purposes $ 2,054,910 $ (1,173,621 ) $ 4,745,461 Net capital (Sec. 1231) gain for Federal income tax reporting purposes 9,560,633 8,193,599 7,424,295 $ 11,615,543 $ 7,019,978 $ 12,169,756 Weighted average number of units of limited partnership interest outstanding 7,753 7,753 7,753 As of December 31, 2020 2019, $51,969,171 $46,324,174 $264,404, $277,606

Note 10 - Management Services

Note 10 - Management Services	12 Months Ended
	Dec. 31, 2020
Notes to Financial Statements
Management Services [Text Block]	( 10 Certain affiliates of the General Partner oversee the management and operation of various real estate properties, including those owned by the Partnership. Services performed by affiliates are billed at actual or allocated cost, percentage of revenues or net equity. For the years ended December 31, 2020, 2019 2018 $58,587, $56,734 $55,409, During 2012 1 2020, 2019 2018 $54,000 During 2019 $16,547.

Note 11 - Fair Value of Financi

Note 11 - Fair Value of Financial Instruments	12 Months Ended
	Dec. 31, 2020
Notes to Financial Statements
Financial Instruments Disclosure [Text Block]	( 11 The Partnership's financial instruments include cash, cash equivalents, other assets, accounts payable and other liabilities. The carrying amount of cash and cash equivalents are reasonable estimates of fair value.

Note 12 - Commitments and Conti

Note 12 - Commitments and Contingencies	12 Months Ended
	Dec. 31, 2020
Notes to Financial Statements
Commitments and Contingencies Disclosure [Text Block]	( 12 The Partnership is a party to certain actions directly arising from its normal business operations. While the ultimate outcome is not not The Partnership leases its property to a tenant under an operating lease agreement, which requires the tenant to pay all or part of certain operating and other expenses of the property. The minimum future rentals to be received in respect of non-cancelable commercial operating leases with unexpired terms in excess of one December 31, 2020 $833,922 2021, $858,940 2022, $884,709 2023 $755,600 2024. 100% Pursuant to the original investment agreement, the Partnership may $3,720,000 not

Note 13 - Subsequent Events

Note 13 - Subsequent Events	12 Months Ended
	Dec. 31, 2020
Notes to Financial Statements
Subsequent Events [Text Block]	( 13 On February 1, 2021 February 1, 2021 $1,300

Schedule III - Real Estate and

Schedule III - Real Estate and Accumulated Depreciation	12 Months Ended
	Dec. 31, 2020
Notes to Financial Statements
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation Disclosure [Text Block]	SCHEDULE III - REAL ESTATE AND ACCUMULATED DEPRECIATION DECEMBER 31, 2020 Column A Column B Column C Column D Initial Cost to the Registrant Costs Capitalized Buildings and Subsequent Description Encumbrances Land Improvements Total to Acquisition INDUSTRIAL FLEX Minnesota - Maple Grove (Eagle Lake Business Center IV) $ - $ 470,000 $ 4,243,385 $ 4,713,385 $ 1,427,716 Column A Column E Column F Gross amount at which Carried at End of Year (Notes a & c) Accumulated Buildings and Depreciation Description Land Improvements Total (Notes b & d) INDUSTRIAL FLEX Minnesota - Maple Grove (Eagle Lake Business Center IV) $ 470,000 $ 5,671,101 $ 6,141,101 $ 2,559,959 SB PARTNERS SCHEDULE III - REAL ESTATE AND ACCUMULATED DEPRECIATION - CONTINUED DECEMBER 31, 2020 Column A Column G Column H Column I Life on which Depreciation in Latest Statement Date of Date of Operations Description Construction Acquired is Computed (years) INDUSTRIAL FLEX Minnesota - Maple Grove (Eagle Lake Business Center IV) 2000 Jun 2002 7 to 39 NOTES TO SCHEDULE III: 2020 2019 2018 (a) Reconciliation of amounts shown in Column E: Balance at beginning of year $ 6,141,101 $ 5,709,859 $ 5,551,365 Additions - Cost of improvements 0 431,242 158,494 Deductions - Sales 0 0 0 Balance at end of year $ 6,141,101 $ 6,141,101 $ 5,709,859 (b) Reconciliation of amounts shown in Column F: Balance at beginning of year $ 2,395,451 $ 2,249,190 $ 2,084,846 Additions - Depreciation expense for the year 164,508 146,261 164,344 Deductions - Sales 0 0 0 $ 2,559,959 $ 2,395,451 $ 2,249,190 (c) Aggregate cost basis for Federal income tax reporting purposes $ 5,648,218 $ 5,648,218 $ 5,216,980 (d) Accumulated depreciation for Federal income tax reporting purposes $ 2,424,429 $ 2,299,877 $ 2,184,074

Note 1 - Organization and Sig_2

Note 1 - Organization and Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2020
Notes Tables
Property, Plant and Equipment [Table Text Block]	Buildings and Improvements (in years) 5 to 40 Furnishings (in years) 5 to 7

Note 3 - Common Area Maintena_2

Note 3 - Common Area Maintenance Reimbursements (Tables)	12 Months Ended
	Dec. 31, 2020
Notes Tables
Disaggregation of Revenue [Table Text Block]	2020 2019 2018 Operating lease income: Fixed lease income (Base Rent) $ 809,632 $ 772,617 $ 746,115 Variable lease income (Recoverable Costs) 367,856 354,128 348,163 Total Rental Income $ 1,177,488 $ 1,126,745 $ 1,094,278

Note 5 - Investments in Real _2

Note 5 - Investments in Real Estate (Tables)	12 Months Ended
	Dec. 31, 2020
Notes Tables
Schedule of Real Estate Properties [Table Text Block]	Real Estate at Cost No. of Year of Type Prop. Acquisition Description 12/31/20 12/31/19 Industrial flex property 1 2002 60,345 sf $ 6,141,101 $ 6,141,101 Less: accumulated depreciation (2,559,959 ) (2,395,451 ) Net book value $ 3,581,142 $ 3,745,650

Note 6 - Assets Measured at F_2

Note 6 - Assets Measured at Fair Value (Tables)	12 Months Ended
	Dec. 31, 2020
Notes Tables
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Table Text Block]	Level 3: Significant Unobservable 2020 Inputs Total Assets Investment in Sentinel Omaha, LLC $ 59,615,139 $ 59,615,139 Reserve for fair value of investment (11,923,033 ) (11,923,033 ) Total assets $ 47,692,106 $ 47,692,106 Level 3: Significant Unobservable 2019 Inputs Total Assets Investment in Sentinel Omaha, LLC $ 51,977,702 $ 51,977,702 Reserve for fair value of investment (10,395,545 ) (10,395,545 ) Total assets $ 41,582,157 $ 41,582,157
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]	Investment in Reserve for Sentinel fair value Omaha, LLC of investment Total Balance at January 1, 2019 $ 53,548,614 $ (10,709,724 ) $ 42,838,890 Equity in net income of investment 6,829,088 - 6,829,088 Distribution from investment (8,400,000 ) (8,400,000 ) Decrease in reserve - 314,179 314,179 Balance at December 31, 2019 51,977,702 (10,395,545 ) 41,582,157 Equity in net income of investment 7,637,437 - 7,637,437 Distribution from investment - - - Increase in reserve - (1,527,488 ) (1,527,488 ) Balance at December 31, 2020 $ 59,615,139 $ (11,923,033 ) $ 47,692,106

Note 7 - Investment in Sentin_2

Note 7 - Investment in Sentinel Omaha, LLC (Tables)	12 Months Ended
	Dec. 31, 2020
Statement of Operations [Member]
Notes Tables
Real Estate Investment Financial Statements, Disclosure [Table Text Block]	Statement of Operations 2020 2019 2018 Rent and other income $ 24,239 $ 26,602 $ 33,786 Real estate operating expenses (12,090 ) (12,618 ) (16,189 ) Other expenses (1,563 ) (3,489 ) (5,705 ) Net unrealized (losses) gains (8,286 ) (1,366 ) 488 Net realized gain (losses) 23,158 13,635 7,094 Net increase in net assets $ 25,458 $ 22,764 $ 19,474
Balance Sheet [Member]
Notes Tables
Real Estate Investment Financial Statements, Disclosure [Table Text Block]	Balance Sheet 2020 2019 Investment in real estate properties, at fair value $ 190,600 $ 230,900 Other assets 61,315 19,825 Debt (49,880 ) (73,892 ) Other liabilities (3,318 ) (3,574 ) Members' equity $ 198,717 $ 173,259
Valuation, Income Approach [Member]
Notes Tables
Fair Value Measurement Inputs and Valuation Techniques [Table Text Block]	Fair Valuation Unobservable Range Value Techniques Inputs (Weighted Average) Investment in real estate properties $ 190,600 Discounted cash flows (DCF) Discount rate 7.12% - 7.75% (7.21%) Capitalization rate 4.75% - 5.50% (5.00%) DCF Term (years) 10

Note 8 - Quarterly Financial _2

Note 8 - Quarterly Financial Information (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2020
Notes Tables
Quarterly Financial Information [Table Text Block]	Revenues from Net Income (Loss) per Equity in Net Continuing Unit of Limited Income (Loss) Year ended December 31, 2020 Operations Net Income (Loss) Partnership Interest of Investment First Quarter $ 293,365 $ 250,359 $ 32.29 $ 484,477 Second Quarter 295,300 (491,128) (63.35) (442,722 ) Third Quarter 293,529 92,443 11.92 315,222 Fourth Quarter 297,524 5,677,955 732.36 7,280,460 Year ended December 31, 2019 First Quarter $ 278,356 $ 189,419 $ 24.43 $ 408,908 Second Quarter 278,993 2,159,145 278.49 795,927 Third Quarter 279,769 1,009,983 130.27 1,439,584 Fourth Quarter 294,366 3,211,163 414.19 4,184,669

Note 9 - Federal Income Tax I_2

Note 9 - Federal Income Tax Information (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2020
Notes Tables
Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]	For the Years Ended December 31, 2020 2019 2018 Net income for financial reporting purposes $ 5,529,629 $ 6,569,710 $ 8,823,652 Difference between tax and financial statement equity in net income/ loss of investment 6,077,663 4,175,809 2,807,300 Difference between accrued investment management fees, mortgage interest and partnership administrative expenses recognized for tax purposes 0 (3,734,253 ) 525,375 Difference between tax and financial statement depreciation 8,251 8,712 13,429 Net income for Federal income tax reporting purposes $ 11,615,543 $ 7,019,978 $ 12,169,756 Net ordinary income (loss) for Federal income tax reporting purposes $ 2,054,910 $ (1,173,621 ) $ 4,745,461 Net capital (Sec. 1231) gain for Federal income tax reporting purposes 9,560,633 8,193,599 7,424,295 $ 11,615,543 $ 7,019,978 $ 12,169,756 Weighted average number of units of limited partnership interest outstanding 7,753 7,753 7,753

Schedule III - Real Estate an_2

Schedule III - Real Estate and Accumulated Depreciation (Tables)	12 Months Ended
	Dec. 31, 2020
Notes Tables
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land and Buildings and Improvements[Table Text Block]	Column A Column B Column C Column D Initial Cost to the Registrant Costs Capitalized Buildings and Subsequent Description Encumbrances Land Improvements Total to Acquisition INDUSTRIAL FLEX Minnesota - Maple Grove (Eagle Lake Business Center IV) $ - $ 470,000 $ 4,243,385 $ 4,713,385 $ 1,427,716
SEC Schedule III, Real Estate and Accumulated Depreciation, Gross Amounts [Table Text Block]	Column A Column E Column F Gross amount at which Carried at End of Year (Notes a & c) Accumulated Buildings and Depreciation Description Land Improvements Total (Notes b & d) INDUSTRIAL FLEX Minnesota - Maple Grove (Eagle Lake Business Center IV) $ 470,000 $ 5,671,101 $ 6,141,101 $ 2,559,959
SEC Schedule III, Real Estate and Accumulated Depreciation, Date Acquired [Table Text Block]	Column A Column G Column H Column I Life on which Depreciation in Latest Statement Date of Date of Operations Description Construction Acquired is Computed (years) INDUSTRIAL FLEX Minnesota - Maple Grove (Eagle Lake Business Center IV) 2000 Jun 2002 7 to 39
SEC Schedule III, Real Estate and Accumulated Depreciation, Reconciliation [Table Text Block]	2020 2019 2018 (a) Reconciliation of amounts shown in Column E: Balance at beginning of year $ 6,141,101 $ 5,709,859 $ 5,551,365 Additions - Cost of improvements 0 431,242 158,494 Deductions - Sales 0 0 0 Balance at end of year $ 6,141,101 $ 6,141,101 $ 5,709,859 (b) Reconciliation of amounts shown in Column F: Balance at beginning of year $ 2,395,451 $ 2,249,190 $ 2,084,846 Additions - Depreciation expense for the year 164,508 146,261 164,344 Deductions - Sales 0 0 0 $ 2,559,959 $ 2,395,451 $ 2,249,190 (c) Aggregate cost basis for Federal income tax reporting purposes $ 5,648,218 $ 5,648,218 $ 5,216,980 (d) Accumulated depreciation for Federal income tax reporting purposes $ 2,424,429 $ 2,299,877 $ 2,184,074

Note 1 - Organization and Sig_3

Note 1 - Organization and Significant Accounting Policies (Details Textual) shares in Thousands	12 Months Ended
	Dec. 31, 2020shares	Dec. 31, 2019shares	Dec. 31, 2018shares
Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage	100.00%
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount (in shares)	0	0	0
Number of Operating Segments	1

Note 1 - Organization and Sig_4

Note 1 - Organization and Significant Accounting Policies - Estimated Useful Lives of Related Properties (Details)	12 Months Ended
	Dec. 31, 2020
Building and Building Improvements [Member] | Minimum [Member]
Estimated useful life of related properties (Year)	5 years
Building and Building Improvements [Member] | Maximum [Member]
Estimated useful life of related properties (Year)	40 years
Furniture and Fixtures [Member] | Minimum [Member]
Estimated useful life of related properties (Year)	5 years
Furniture and Fixtures [Member] | Maximum [Member]
Estimated useful life of related properties (Year)	7 years

Note 3 - Common Area Maintena_3

Note 3 - Common Area Maintenance Reimbursements - Disaggregation of Rental Income (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Rental income	$ 1,177,488	$ 1,126,745	$ 1,094,278
Fixed Lease Income Base Rent [Member]
Rental income	809,632	772,617	746,115
Variable Lease Income [Member]
Rental income	$ 367,856	$ 354,128	$ 348,163

Note 4 - Investment Managemen_2

Note 4 - Investment Management Agreement (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Property Management Fee, Percent Fee	2.00%
Management Fee Percentage Other Than Real Estate	0.50%
Management Fee Expense	$ 1,018,617	$ 1,007,137	$ 911,615
Percentage of Cash Distribution in Excess of Annual Distribution			25.00%
Cash Distribution in Excess of Annual Distribution	0	0	$ 0
Accounts Payable and Accrued Liabilities [Member]
Deferred Compensation Arrangement with Individual, Recorded Liability			485,375
General Partner [Member]
Management Fee Expense	$ 1,018,617	$ 1,007,137	$ 911,615

Note 5 - Investments in Real _3

Note 5 - Investments in Real Estate - Summary of Investments in Real Estate (Details)	12 Months Ended
	Dec. 31, 2020USD ($)ft²	Dec. 31, 2019USD ($)
Less: accumulated depreciation	$ (2,559,959)	$ (2,395,451)
Net book value	$ 3,581,142	3,745,650
Industrial Flex Property [Member]
No. of Prop.	1
Year of Acquisition	2002
Description (Square Foot) | ft²	60,345
Investment in real estate, at cost	$ 6,141,101	6,141,101
Less: accumulated depreciation	(2,559,959)	(2,395,451)
Net book value	$ 3,581,142	$ 3,745,650

Note 6 - Assets Measured at F_3

Note 6 - Assets Measured at Fair Value (Details Textual)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2018	Dec. 31, 2007
Sentinel Omaha LLC [Member]
Equity Method Investment, Ownership Percentage			30.00%
Equity Method Investment, Fair Value, Reserve, Percent	20.00%	20.00%
Sentinel Omaha LLC [Member]
Equity Method Investment, Ownership Percentage		30.00%
Increase in Real Estate Values, Percentage	3.80%

Note 6 - Assets Measured at F_4

Note 6 - Assets Measured at Fair Value - Fair Value Measurement of Assets (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Reserve for fair value of investment	$ (11,923,033)	$ (10,395,545)
Total assets	47,692,106	41,582,157
Sentinel Omaha LLC [Member]
Investment in Sentinel Omaha, LLC	59,615,139	51,977,702
Reserve for fair value of investment	(11,923,033)	(10,395,545)
Total assets	47,692,106	41,582,157
Fair Value, Inputs, Level 3 [Member] | Sentinel Omaha LLC [Member]
Investment in Sentinel Omaha, LLC	59,615,139	51,977,702	$ 53,548,614
Reserve for fair value of investment	(11,923,033)	(10,395,545)
Total assets	$ 47,692,106	$ 41,582,157	$ 42,838,890

Note 6 - Assets Measured at F_5

Note 6 - Assets Measured at Fair Value - Reconciliation of Assets Measured at Fair Value (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Equity in net income of investment	$ 7,280,460	$ 315,222	$ (442,722)	$ 484,477	$ 4,184,669	$ 1,439,584	$ 795,927	$ 408,908	$ 7,637,437	$ 6,829,088	$ 5,842,182
Distribution from investment										(8,400,000)	(2,400,000)
(Increase) decrease in reserve for value of investment									(1,527,488)	314,179	1,816,884
Balance				41,582,157					41,582,157
Balance	47,692,106				41,582,157				47,692,106	41,582,157
Sentinel Omaha LLC [Member]
Balance, Investment in Sentinel Omaha, LLC				51,977,702					51,977,702
Balance, Investment in Sentinel Omaha, LLC	59,615,139				51,977,702				59,615,139	51,977,702
Balance				41,582,157					41,582,157
Balance	47,692,106				41,582,157				47,692,106	41,582,157
Fair Value, Inputs, Level 3 [Member] | Sentinel Omaha LLC [Member]
Balance, Investment in Sentinel Omaha, LLC				51,977,702				53,548,614	51,977,702	53,548,614
Equity in net income of investment									7,637,437	6,829,088
Distribution from investment										(8,400,000)
(Increase) decrease in reserve for value of investment
Balance, Investment in Sentinel Omaha, LLC	59,615,139				51,977,702				59,615,139	51,977,702	53,548,614
Balance, Reserve for fair value of investment				(10,395,545)				(10,709,724)	(10,395,545)	(10,709,724)
(Increase) decrease in reserve for fair value investment									(1,527,488)	314,179
Balance, Reserve for fair value of investment	(11,923,033)				(10,395,545)				(11,923,033)	(10,395,545)	(10,709,724)
Balance				$ 41,582,157				$ 42,838,890	41,582,157	42,838,890
Balance	$ 47,692,106				$ 41,582,157				$ 47,692,106	$ 41,582,157	$ 42,838,890

Note 7 - Investment in Sentin_3

Note 7 - Investment in Sentinel Omaha, LLC (Details Textual) - Sentinel Omaha LLC [Member]	Dec. 31, 2020	Dec. 31, 2007USD ($)
Investment Owned, at Cost		$ 37,200,000
Equity Method Investment, Ownership Percentage		30.00%
Number of Multifamily Properties	5
Number of Markets	3

Note 7 - Investment in Sentin_4

Note 7 - Investment in Sentinel Omaha, LLC - Balance Sheet (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Other assets	$ 11,198	$ 8,743
Sentinel Omaha LLC [Member]
Investment in real estate properties, at fair value	190,600,000	230,900,000
Other assets	61,315,000	19,825,000
Debt	(49,880,000)	(73,892,000)
Other liabilities	(3,318,000)	(3,574,000)
Members' equity	$ 198,717,000	$ 173,259,000

Note 7 - Investment in Sentin_5

Note 7 - Investment in Sentinel Omaha, LLC - Statement of Operations (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Rent and other income	$ 297,524	$ 293,529	$ 295,300	$ 293,365	$ 294,366	$ 279,769	$ 278,993	$ 278,356	$ 1,179,718	$ 1,131,484	$ 1,110,456
Real estate operating expenses									(312,558)	(304,542)	(304,672)
Other expenses									(122,783)	(117,545)	(129,967)
Net increase in net assets									5,529,629	6,569,710	8,823,652
Sentinel Omaha LLC [Member]
Rent and other income									24,239,000	26,602,000	33,786,000
Real estate operating expenses									(12,090,000)	(12,618,000)	(16,189,000)
Other expenses									(1,563,000)	(3,489,000)	(5,705,000)
Net unrealized (losses) gains									(8,286,000)	(1,366,000)	488,000
Net realized gain (losses)									23,158,000	13,635,000	7,094,000
Net increase in net assets									$ 25,458,000	$ 22,764,000	$ 19,474,000

Note 7 - Investment in Sentin_6

Note 7 - Investment in Sentinel Omaha, LLC - Significant Unobservable Inputs Related to Fair Value Measurement (Details) - Fair Value, Inputs, Level 3 [Member] $ in Millions	Dec. 31, 2020USD ($)
Measurement Input, Expected Term [Member]
Investment in real estate properties	10
Minimum [Member] | Measurement Input, Cap Rate [Member]
Investment in real estate properties	0.0475
Maximum [Member] | Measurement Input, Cap Rate [Member]
Investment in real estate properties	0.055
Weighted Average [Member] | Measurement Input, Cap Rate [Member]
Investment in real estate properties	(0.05)
Real Estate [Member]
Investment in real estate properties	$ 190.6
Real Estate [Member] | Minimum [Member] | Measurement Input, Discount Rate [Member]
Investment in real estate properties	0.0712
Real Estate [Member] | Maximum [Member] | Measurement Input, Discount Rate [Member]
Investment in real estate properties	0.0775
Real Estate [Member] | Weighted Average [Member] | Measurement Input, Discount Rate [Member]
Investment in real estate properties	(0.0721)

Note 8 - Quarterly Financial _3

Note 8 - Quarterly Financial Information (Unaudited) - Summarized Quarterly Financial Data (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Rent and other income	$ 297,524	$ 293,529	$ 295,300	$ 293,365	$ 294,366	$ 279,769	$ 278,993	$ 278,356	$ 1,179,718	$ 1,131,484	$ 1,110,456
First Quarter, Net Income (Loss)	$ 5,677,955	$ 92,443	$ (491,128)	$ 250,359	$ 3,211,163	$ 1,009,983	$ 2,159,145	$ 189,419
First Quarter, Net Income (Loss) per Unit of Limited Partnership Interest (in dollars per share)	$ 732.36	$ 11.92	$ (63.35)	$ 32.29	$ 414.19	$ 130.27	$ 278.49	$ 24.43	$ 713.22	$ 847.38	$ 1,138.10
Equity in net income of investment	$ 7,280,460	$ 315,222	$ (442,722)	$ 484,477	$ 4,184,669	$ 1,439,584	$ 795,927	$ 408,908	$ 7,637,437	$ 6,829,088	$ 5,842,182

Note 9 - Federal Income Tax I_3

Note 9 - Federal Income Tax Information (Unaudited) (Details Textual) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Partnership Assets for Tax Basis	$ 51,969,171	$ 46,324,174
Partnership Liabilities for Tax Basis	$ 264,404	$ 277,606

Note 9 - Federal Income Tax I_4

Note 9 - Federal Income Tax Information (Unaudited) - Reconciliation of Net Income (Loss) of Financial Reporting to Net Income (Loss) for Federal Income Tax Reporting (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Net increase in net assets	$ 5,529,629	$ 6,569,710	$ 8,823,652
Difference between tax and financial statement equity in net income/ loss of investment	6,077,663	4,175,809	2,807,300
Difference between accrued investment management fees, mortgage interest and partnership administrative expenses recognized for tax purposes	0	(3,734,253)	525,375
Difference between tax and financial statement depreciation	8,251	8,712	13,429
Net income for Federal income tax reporting purposes	11,615,543	7,019,978	12,169,756
Net ordinary income (loss) for Federal income tax reporting purposes	2,054,910	(1,173,621)	4,745,461
Net capital (Sec. 1231) gain for Federal income tax reporting purposes	9,560,633	8,193,599	7,424,295
Net Loss for Federal Income Tax Reporting Purposes	$ 11,615,543	$ 7,019,978	$ 12,169,756
Weighted Average Number of Units of Limited Partnership Interest Outstanding (in shares)	7,753	7,753	7,753

Note 10 - Management Services (

Note 10 - Management Services (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cost of Goods and Services Sold, Total	$ 312,558	$ 304,542	$ 304,672
Management Fee Expense	1,018,617	1,007,137	911,615
Affiliated Entity [Member]
Management Fee Expense		16,547
Management Service [Member]
Cost of Goods and Services Sold, Total	58,587	56,734	55,409
Asset Management [Member]
Cost of Goods and Services Sold, Total	$ 54,000	$ 54,000	$ 54,000

Note 12 - Commitments and Con_2

Note 12 - Commitments and Contingencies (Details Textual)	12 Months Ended
	Dec. 31, 2020USD ($)
Lessor, Operating Lease, Payment to be Received, Year One	$ 833,922
Lessor, Operating Lease, Payment to be Received, Year Two	858,940
Lessor, Operating Lease, Payment to be Received, Year Three	884,709
Lessor, Operating Lease, Payment to be Received, Year Four	755,600
Additional Capital Investment to be Made	$ 3,720,000
Maple Grove (Eagle Lake Business Center IV) [Member]
Operating Lease, Tenant Leasing Percentage	100.00%

Note 13 - Subsequent Events (De

Note 13 - Subsequent Events (Details Textual)	Feb. 01, 2021$ / shares
Subsequent Event [Member]
Distributions Per General Partnership Unit Outstanding (in dollars per share)	$ 1,300

Schedule III - Real Estate an_3

Schedule III - Real Estate and Accumulated Depreciation - Real Estate and Accumulated Depreciation Initial Cost (Details) - Industrial Flex Minnesota [Member] - Maple Grove (Eagle Lake Business Center IV) [Member]	Dec. 31, 2020USD ($)
Initial cost, land	$ 470,000
Initial cost, buildings and improvements	4,243,385
Initial cost	4,713,385
Cost capitalized subsequent to acquistion	$ 1,427,716

Schedule III - Real Estate an_4

Schedule III - Real Estate and Accumulated Depreciation - Real Estate and Accumulated Depreciation Gross Amount (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accumulated depreciation	$ 2,559,959	$ 2,395,451	$ 2,249,190	$ 2,084,846
Industrial Flex Minnesota [Member] | Maple Grove (Eagle Lake Business Center IV) [Member]
Carrying amount, land	470,000
Carrying amount, buildings and improvements	5,671,101
Carrying amount, total	6,141,101
Accumulated depreciation	$ 2,559,959

Schedule III - Real Estate an_5

Schedule III - Real Estate and Accumulated Depreciation - Real Estate and Accumulated Depreciation, Life On Which Depreciation Is Computed (Details) - Industrial Flex Minnesota [Member] - Maple Grove (Eagle Lake Business Center IV) [Member]	12 Months Ended
	Dec. 31, 2020
Minimum [Member]
Life on which depreciation in latest statement of operations is computed (Year)	7 years
Maximum [Member]
Life on which depreciation in latest statement of operations is computed (Year)	39 years

Schedule III - Real Estate an_6

Schedule III - Real Estate and Accumulated Depreciation - Real Estate and Accumulated Depreciation Reconciliation (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
(a) Reconciliation of amounts shown in Column E:
Balance	$ 6,141,101	$ 5,709,859	$ 5,551,365
Cost of improvements	0	431,242	158,494
Sales	0	0	0
Balance	6,141,101	6,141,101	5,709,859
(b) Reconciliation of amounts shown in Column F:
Balance	2,395,451	2,249,190	2,084,846
Depreciation expense for the year	164,508	146,261	164,344
Sales	0	0	0
Balance	2,559,959	2,395,451	2,249,190
(c) Aggregate cost basis for Federal income tax reporting purposes	5,648,218	5,648,218	5,216,980
(d) Accumulated depreciation for Federal income tax reporting purposes	$ 2,424,429	$ 2,299,877	$ 2,184,074