REAL ESTATE INVESTMENTS - Schedule of Real Estate Properties (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Real Estate [Line Items]
Land, Buildings and Improvements	$ 337,755,793
Tenant origination and absorption costs	23,792,057	$ 27,266,610
Accumulated Depreciation and Amortization	(32,091,211)	(20,411,794)
Total Investment in Real Estate Property, Net	329,456,639	$ 403,535,694
Office | Accredo Health
Real Estate [Line Items]
Land, Buildings and Improvements	9,855,847
Tenant origination and absorption costs	1,269,351
Accumulated Depreciation and Amortization	(2,221,380)
Total Investment in Real Estate Property, Net	8,903,818
Office | Northrop Grumman
Real Estate [Line Items]
Land, Buildings and Improvements	12,382,991
Tenant origination and absorption costs	1,341,199
Accumulated Depreciation and Amortization	(2,968,985)
Total Investment in Real Estate Property, Net	10,755,205
Office | exp US Services
Real Estate [Line Items]
Land, Buildings and Improvements	6,056,668
Tenant origination and absorption costs	388,248
Accumulated Depreciation and Amortization	(833,278)
Total Investment in Real Estate Property, Net	5,611,638
Office | Wyndham
Real Estate [Line Items]
Land, Buildings and Improvements	10,406,483
Tenant origination and absorption costs	669,232
Accumulated Depreciation and Amortization	(1,170,222)
Total Investment in Real Estate Property, Net	9,905,493
Office | Williams Sonoma
Real Estate [Line Items]
Land, Buildings and Improvements	8,079,612
Tenant origination and absorption costs	550,486
Accumulated Depreciation and Amortization	(1,058,455)
Total Investment in Real Estate Property, Net	7,571,643
Office | EMCOR
Real Estate [Line Items]
Land, Buildings and Improvements	5,960,610
Tenant origination and absorption costs	463,488
Accumulated Depreciation and Amortization	(604,163)
Total Investment in Real Estate Property, Net	5,819,935
Office | Cummins
Real Estate [Line Items]
Land, Buildings and Improvements	14,465,491
Tenant origination and absorption costs	1,536,998
Accumulated Depreciation and Amortization	(2,151,938)
Total Investment in Real Estate Property, Net	13,850,551
Office | Texas Health
Real Estate [Line Items]
Land, Buildings and Improvements	6,976,703
Tenant origination and absorption costs	713,221
Accumulated Depreciation and Amortization	(681,341)
Total Investment in Real Estate Property, Net	7,008,583
Office | Bon Secours
Real Estate [Line Items]
Land, Buildings and Improvements	10,388,751
Tenant origination and absorption costs	800,356
Accumulated Depreciation and Amortization	(978,335)
Total Investment in Real Estate Property, Net	10,210,772
Office | Costco
Real Estate [Line Items]
Land, Buildings and Improvements	27,330,797
Tenant origination and absorption costs	2,765,136
Accumulated Depreciation and Amortization	(2,654,329)
Total Investment in Real Estate Property, Net	27,441,604
Office | GSA (MSHA)
Real Estate [Line Items]
Land, Buildings and Improvements	3,112,076
Tenant origination and absorption costs	243,307
Accumulated Depreciation and Amortization	(138,515)
Total Investment in Real Estate Property, Net	3,216,868
Office | Solar Turbines
Real Estate [Line Items]
Land, Buildings and Improvements	7,133,241
Tenant origination and absorption costs	284,026
Accumulated Depreciation and Amortization	(338,232)
Total Investment in Real Estate Property, Net	7,079,035
Office | Gap
Real Estate [Line Items]
Land, Buildings and Improvements	8,378,276
Tenant origination and absorption costs	360,377
Accumulated Depreciation and Amortization	(479,306)
Total Investment in Real Estate Property, Net	8,259,347
Office | Sutter Health
Real Estate [Line Items]
Land, Buildings and Improvements	29,555,055
Tenant origination and absorption costs	1,616,610
Accumulated Depreciation and Amortization	(1,080,349)
Total Investment in Real Estate Property, Net	30,091,316
Retail | Dollar General, Litchfield
Real Estate [Line Items]
Land, Buildings and Improvements	1,281,812
Tenant origination and absorption costs	116,302
Accumulated Depreciation and Amortization	(166,006)
Total Investment in Real Estate Property, Net	1,232,108
Retail | Dollar General, Wilton
Real Estate [Line Items]
Land, Buildings and Improvements	1,543,776
Tenant origination and absorption costs	140,653
Accumulated Depreciation and Amortization	(212,451)
Total Investment in Real Estate Property, Net	1,471,978
Retail | Dollar General, Thompsontown
Real Estate [Line Items]
Land, Buildings and Improvements	1,199,860
Tenant origination and absorption costs	106,730
Accumulated Depreciation and Amortization	(159,501)
Total Investment in Real Estate Property, Net	1,147,089
Retail | Dollar General, Mt. Gilead
Real Estate [Line Items]
Land, Buildings and Improvements	1,174,188
Tenant origination and absorption costs	111,847
Accumulated Depreciation and Amortization	(152,925)
Total Investment in Real Estate Property, Net	1,133,110
Retail | Dollar General, Lakeside
Real Estate [Line Items]
Land, Buildings and Improvements	1,112,872
Tenant origination and absorption costs	100,857
Accumulated Depreciation and Amortization	(156,949)
Total Investment in Real Estate Property, Net	1,056,780
Retail | Dollar General, Castalia
Real Estate [Line Items]
Land, Buildings and Improvements	1,102,086
Tenant origination and absorption costs	86,408
Accumulated Depreciation and Amortization	(152,492)
Total Investment in Real Estate Property, Net	1,036,002
Retail | Dollar General, Bakersfield
Real Estate [Line Items]
Land, Buildings and Improvements	4,899,714
Tenant origination and absorption costs	261,630
Accumulated Depreciation and Amortization	(147,132)
Total Investment in Real Estate Property, Net	5,014,212
Retail | PreK Education
Real Estate [Line Items]
Land, Buildings and Improvements	12,447,287
Tenant origination and absorption costs	447,927
Accumulated Depreciation and Amortization	(599,428)
Total Investment in Real Estate Property, Net	12,295,786
Retail | Dollar Tree
Real Estate [Line Items]
Land, Buildings and Improvements	1,320,367
Tenant origination and absorption costs	73,298
Accumulated Depreciation and Amortization	(70,911)
Total Investment in Real Estate Property, Net	1,322,754
Retail | Dollar General, Big Spring
Real Estate [Line Items]
Land, Buildings and Improvements	1,281,683
Tenant origination and absorption costs	76,351
Accumulated Depreciation and Amortization	(50,969)
Total Investment in Real Estate Property, Net	1,307,065
Retail | Walgreens, Santa Maria
Real Estate [Line Items]
Land, Buildings and Improvements	5,223,442
Tenant origination and absorption costs	335,945
Accumulated Depreciation and Amortization	(132,961)
Total Investment in Real Estate Property, Net	5,426,426
Industrial | Dana
Real Estate [Line Items]
Land, Buildings and Improvements	6,802,876
Tenant origination and absorption costs	531,439
Accumulated Depreciation and Amortization	(1,835,800)
Total Investment in Real Estate Property, Net	5,498,515
Industrial | Omnicare
Real Estate [Line Items]
Land, Buildings and Improvements	7,262,747
Tenant origination and absorption costs	281,442
Accumulated Depreciation and Amortization	(832,474)
Total Investment in Real Estate Property, Net	6,711,715
Industrial | Husqvarna
Real Estate [Line Items]
Land, Buildings and Improvements	11,840,200
Tenant origination and absorption costs	1,013,948
Accumulated Depreciation and Amortization	(1,113,651)
Total Investment in Real Estate Property, Net	11,740,497
Industrial | AvAir
Real Estate [Line Items]
Land, Buildings and Improvements	27,357,900
Tenant origination and absorption costs	0
Accumulated Depreciation and Amortization	(2,111,134)
Total Investment in Real Estate Property, Net	25,246,766
Industrial | 3M
Real Estate [Line Items]
Land, Buildings and Improvements	14,762,819
Tenant origination and absorption costs	2,356,361
Accumulated Depreciation and Amortization	(3,476,588)
Total Investment in Real Estate Property, Net	13,642,592
Industrial | Taylor Fresh Foods
Real Estate [Line Items]
Land, Buildings and Improvements	34,194,369
Tenant origination and absorption costs	2,894,017
Accumulated Depreciation and Amortization	(1,597,022)
Total Investment in Real Estate Property, Net	35,491,364
Industrial | Levins
Real Estate [Line Items]
Land, Buildings and Improvements	4,429,390
Tenant origination and absorption costs	221,927
Accumulated Depreciation and Amortization	(220,609)
Total Investment in Real Estate Property, Net	4,430,708
Industrial | PMI Preclinical
Real Estate [Line Items]
Land, Buildings and Improvements	9,672,174
Tenant origination and absorption costs	408,225
Accumulated Depreciation and Amortization	(204,321)
Total Investment in Real Estate Property, Net	9,876,078
Industrial | Wood Group
Real Estate [Line Items]
Land, Buildings and Improvements	9,731,220
Tenant origination and absorption costs	466,293
Accumulated Depreciation and Amortization	(565,017)
Total Investment in Real Estate Property, Net	9,632,496
Industrial | ITW Rippey
Real Estate [Line Items]
Land, Buildings and Improvements	7,071,143
Tenant origination and absorption costs	304,387
Accumulated Depreciation and Amortization	(303,219)
Total Investment in Real Estate Property, Net	7,072,311
Industrial | L-3 Communications
Real Estate [Line Items]
Land, Buildings and Improvements	11,631,857
Tenant origination and absorption costs	454,035
Accumulated Depreciation and Amortization	(470,823)
Total Investment in Real Estate Property, Net	11,615,069
Land | Northrop Grumman Parcel
Real Estate [Line Items]
Land, Buildings and Improvements	329,410
Tenant origination and absorption costs	0
Accumulated Depreciation and Amortization	0
Total Investment in Real Estate Property, Net	$ 329,410