Investment in Real Estate - Schedule of Interest in Real Properties (Detail)	6 Months Ended
Jun. 30, 2020 USD ($) ft² property
Real Estate Properties [Line Items]
Ownership Percentage	100.00%
Number of Properties \| property	13
Walgreens Grand Rapids ("GR Property") [Member] \| Grand Rapids, MI [Member]
Real Estate Properties [Line Items]
Ownership Percentage	100.00%
Number of Properties \| property	1
Square Feet \| ft²	14,552
Remaining Lease Term	12 years 1 month 6 days
Annualized Rental Income	$ 500,000
Acquisition Date	2017-07
Purchase Price	$ 7,936,508
CF Net Lease Portfolio IV DST ("DST Properties") [Member]
Real Estate Properties [Line Items]
Ownership Percentage	100.00%
Number of Properties \| property	7
Square Feet \| ft²	103,537
Remaining Lease Term	11 years 4 months 24 days
Annualized Rental Income	$ 2,323,749
Acquisition Date	2017-09
Purchase Price	$ 35,706,642
Daimler Trucks North America Office Building ("FM Property") [Member] \| Fort Mill, SC [Member]
Real Estate Properties [Line Items]
Ownership Percentage	100.00%
Number of Properties \| property	1
Square Feet \| ft²	150,164
Remaining Lease Term	8 years 4 months 24 days
Annualized Rental Income	$ 2,670,638
Acquisition Date	2018-02
Purchase Price	$ 40,000,000
Alliance Data Systems Office Building ("CO Property") [Member] \| Columbus, OH [Member]
Real Estate Properties [Line Items]
Ownership Percentage	100.00%
Number of Properties \| property	1
Square Feet \| ft²	241,493
Remaining Lease Term	12 years 2 months 12 days
Annualized Rental Income	$ 3,362,844
Acquisition Date	2018-07
Purchase Price	$ 46,950,000
Hoya Optical Labs of America ("Lewisville Property") [Member] \| Lewisville, TX [Member]
Real Estate Properties [Line Items]
Ownership Percentage	100.00%
Number of Properties \| property	1
Square Feet \| ft²	89,473
Remaining Lease Term	7 years 10 months 24 days
Annualized Rental Income	$ 937,060
Acquisition Date	2018-11
Purchase Price	$ 14,120,000
Williams Sonoma Office Building ("SF Property") [Member] \| San Francisco, CA [Member]
Real Estate Properties [Line Items]
Ownership Percentage	75.00%
Number of Properties \| property	1
Square Feet \| ft²	13,907
Remaining Lease Term	1 year 4 months 24 days
Annualized Rental Income	$ 582,860
Acquisition Date	2019-09
Purchase Price	$ 11,600,000
Martin Brower Industrial Buildings ("Buchanan Property") [Member] \| Phoenix, AZ [Member]
Real Estate Properties [Line Items]
Ownership Percentage	100.00%
Number of Properties \| property	1
Square Feet \| ft²	93,302
Remaining Lease Term	11 years 8 months 12 days
Annualized Rental Income	$ 1,083,444
Acquisition Date	2019-11
Purchase Price	$ 17,300,000

Asset purchase price.

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- Definition

Business acquisition, effective month and year.

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- Definition

Area of a real estate property.

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- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

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The number of real estate properties owned as of the balance sheet date.

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- Definition

Amount of operating lease income from lease payments and variable lease payments paid and payable to lessor. Includes, but is not limited to, variable lease payments not included in measurement of lease receivable.

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- Definition

Weighted average remaining lease term for operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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