Subsequent Events - Additional Information (Detail) - USD ($)							12 Months Ended
	Mar. 29, 2019	Mar. 19, 2019	Mar. 12, 2019	Feb. 23, 2019	Dec. 20, 2018	Feb. 23, 2018	Dec. 31, 2018	Dec. 31, 2017
Subsequent Event [Line Items]
Gross proceeds from issuance of common stock							$ 18,131,683	$ 75,517,069
Common stock daily distribution declared					$ 0.0016980822
Common stock daily distribution declared date					Dec. 20, 2018
Cash distribution record date end					Mar. 31, 2019
KeyBank Bridge Loans [Member]
Subsequent Event [Line Items]
Loan maturity date						Feb. 23, 2019
Class A Common Stock [Member]
Subsequent Event [Line Items]
Number of common stock issued							126,000
Class T Common Stock [Member]
Subsequent Event [Line Items]
Number of common stock issued							36,000
Class W Common Stock [Member]
Subsequent Event [Line Items]
Number of common stock issued							44,000
Subsequent Event
Subsequent Event [Line Items]
Gross proceeds from issuance of common stock		$ 3,500,000
Common stock daily distribution declared			$ 0.0016980822
Common stock daily distribution declared date			Mar. 12, 2019
Cash distribution record date end			Apr. 01, 2019
Cash distribution record date end			Jun. 30, 2019
Subsequent Event | KeyBank Bridge Loans [Member]
Subsequent Event [Line Items]
Payment of loans made by operating partnership				$ 60,000
Commitment fee percentage on loan principal outstanding				0.50%
Loan maturity date				Aug. 23, 2019
Subsequent Event | Full KeyBank Bridge Loan [Member]
Subsequent Event [Line Items]
Loan maturity date	Apr. 30, 2020
Subsequent Event | Class A Common Stock [Member]
Subsequent Event [Line Items]
Number of common stock issued		236,000
Subsequent Event | Class T Common Stock [Member]
Subsequent Event [Line Items]
Number of common stock issued		47,000
Common stock daily distribution declared			$ 0.00142
Subsequent Event | Class W Common Stock [Member]
Subsequent Event [Line Items]
Number of common stock issued		67,000
Common stock daily distribution declared			$ 0.00157