Debt - Schedule of Company's Outstanding Debt (Detail) - USD ($)				9 Months Ended
		Sep. 28, 2017	Jun. 28, 2017	Sep. 30, 2018		Aug. 31, 2018	Feb. 23, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Carrying Value				$ 204,456,864
Debt issuance costs, net				(2,345,183)				$ (700,362)
Total debt				202,111,681				52,299,638
JPM Mortgage Loan [Member] | Fayetteville Property [Member]
Debt Instrument [Line Items]
Carrying Value	[1]			$ 29,500,000				29,500,000
Debt instrument, initial interest rate			4.20%	4.20%	[1]
Maturity Date			Jul. 01, 2024	Jul. 01, 2024	[1]
Nationwide Loan [Member]
Debt Instrument [Line Items]
Debt instrument, initial interest rate		3.84%
Maturity Date		Oct. 01, 2024
Nationwide Loan [Member] | Tallahassee Property [Member]
Debt Instrument [Line Items]
Carrying Value	[1]			$ 23,500,000				$ 23,500,000
Debt instrument, initial interest rate	[1]			3.84%
Maturity Date	[1]			Oct. 01, 2024
Utah Freddie Mac Mortgage Loans [Member]
Debt Instrument [Line Items]
Carrying Value	[2]			$ 46,905,000
Debt instrument, initial interest rate				5.06%	[2]		5.06%
Maturity Date	[2]			Feb. 23, 2028
Portland Freddie Mac Mortgage Loan [Member]
Debt Instrument [Line Items]
Carrying Value	[3]			$ 63,200,000
Debt instrument, initial interest rate				4.86%	[3]	4.86%
Maturity Date	[3]			Sep. 01, 2028
Utah Bridge Loan [Member]
Debt Instrument [Line Items]
Carrying Value	[4]			$ 14,351,864
Debt instrument, initial interest rate	[4]			6.22%
Maturity Date	[4]			Feb. 23, 2019
Portland Initial Bridge Loan [Member]
Debt Instrument [Line Items]
Carrying Value	[5]			$ 27,000,000
Debt instrument, initial interest rate	[5]			6.25%
Maturity Date	[5]			Aug. 31, 2019

[1] Fixed rate debt with interest only payments due monthly and the principal balance due upon maturity.

[2] Represents the aggregate of three separate mortgage loans for three properties acquired in Utah. Fixed rate debt with interest only payments due monthly for the first two years, then principal and interest on a 30-year amortization schedule thereafter.

[3] Fixed rate debt with interest only payments due monthly for the first four years, then principal and interest on a 30-year amortization schedule thereafter.

[4] Variable rate debt with interest only payments due monthly. The variable rate reflected in the table was the rate in effect as of September 30, 2018. The loan may be extended six months from the maturity date upon the payment of a fee equal to 0.50% of the outstanding principal balance of the loan at the time of such extension and certain other terms are met, such as there has not been an event of default.

[5] Variable rate debt with interest only payments due monthly. The variable rate reflected in the table was the rate in effect as of September 30, 2018. The loan may be extended eight months from the maturity date upon the payment of a fee equal to 0.50% of the outstanding principal balance of the loan at the time of such extension and certain other terms are met, such as there has not been an event of default.