SUBSEQUENT EVENTS - Narrative (Details)							2 Months Ended	3 Months Ended
	Nov. 12, 2021 USD ($) lease	Nov. 11, 2021 USD ($)	Oct. 29, 2021 USD ($)	Oct. 27, 2021 USD ($)	Oct. 25, 2021 USD ($) $ / shares	Oct. 01, 2021 USD ($) shares	Dec. 31, 2021 USD ($) day property	Dec. 31, 2021 USD ($) day property	Jan. 31, 2022 USD ($) property day	Nov. 24, 2021 $ / shares	Sep. 30, 2021 USD ($) $ / shares	Aug. 04, 2021 $ / shares	May 05, 2021 $ / shares	Jan. 27, 2021 $ / shares	Dec. 31, 2020 USD ($)	Dec. 31, 2019 $ / shares
Subsequent Event [Line Items]
Net asset value (in usd per share) | $ / shares												$ 26.05	$ 24.61	$ 23.03		$ 30.48
Accrued distributions											$ 786,120				$ 706,106
Class C and Class S
Subsequent Event [Line Items]
Net asset value (in usd per share) | $ / shares											$ 27.29
Subsequent Event | Proposed KeyBank Credit Facility
Subsequent Event [Line Items]
Maximum borrowing capacity	$ 225,000,000
Subsequent Event | Forecast
Subsequent Event [Line Items]
Period for due diligence | day									30
Period to complete sale | day									60
Properties to be sold | property									3
Remaining lease term									5 years
Subsequent Event | Forecast | Crowdfunding-Related Intangible Assets
Subsequent Event [Line Items]
Impairment of intangible assets								$ 3,700,000
Subsequent Event | L3Harris
Subsequent Event [Line Items]
Discount term				2 months
Discount amount				$ 139,258
Lease commissions				$ 208,087
Subsequent Event | 3M property
Subsequent Event [Line Items]
Lease commissions			$ 640,696
Tenant improvement allowance			1,026,000
Subsequent Event | Walgreens | Forecast
Subsequent Event [Line Items]
Contract purchase price							$ 28,651,000
Subsequent Event | Walgreens | Forecast | Ten Retail Properties Leased To Walgreen's
Subsequent Event [Line Items]
Asset acquisition, consideration transferred							$ 63,100,000
Number of retail properties acquired | property							10	10
Asset acquisition, consideration transferred, liabilities incurred							$ 35,048,994	$ 35,048,994
Subsequent Event | Texas Health
Subsequent Event [Line Items]
Period for due diligence | day							30	30
Period to complete sale | day							10	10
Subsequent Event | Texas Health | Forecast | Disposal Group, Disposed of by Sale, Not Discontinued Operations
Subsequent Event [Line Items]
Disposal group, including discontinued operation, consideration							$ 15,300,000	$ 15,300,000	$ 27,240,000
Subsequent Event | Industrial Property In Archbold, Ohio | Industrial Property For Manufacturing
Subsequent Event [Line Items]
Asset acquisition, consideration transferred			$ 11,460,000
Subsequent Event | Bon Secours and Omnicare | Forecast
Subsequent Event [Line Items]
Properties to be sold | property									2
Subsequent Event | Class C
Subsequent Event [Line Items]
Common stock redeemed (in shares) | shares						80,614
Common stock redeemed during period						$ 2,098,452
Subsequent Event | Class S
Subsequent Event [Line Items]
Common stock redeemed (in shares) | shares						0
Subsequent Event | Class C and Class S
Subsequent Event [Line Items]
Dividends, common stock					$ 643,025
Daily distribution rate (in usd per share) | $ / shares					$ 0.00287670
Annualized distribution rate (in usd per share) | $ / shares					$ 1.05					$ 1.15
Net asset value, percentage					4.03%					4.21%
Subsequent Event | Class C and Class S | Forecast
Subsequent Event [Line Items]
Daily distribution rate (in usd per share) | $ / shares										$ 0.00315070
Subsequent Event | Series A Preferred Stock
Subsequent Event [Line Items]
Dividends, preferred stock		$ 1,065,278
Accrued distributions		$ 143,403
Subsequent Event | Line of Credit | Revolving Credit Facility | Proposed KeyBank Credit Facility
Subsequent Event [Line Items]
Debt instrument, term	4 years
Extension option | lease	12
Subsequent Event | Term Loan | Proposed KeyBank Credit Facility
Subsequent Event [Line Items]
Debt instrument, term	5 years