Declaration of Distributions - Additional Information (Detail)	Sep. 26, 2018 $ / shares
Schedule Of Stockholders Equity [Line Items]
Common stock daily distribution declared	$ 0.0016980822
Common stock daily distribution declared date	Sep. 26, 2018
Cash distribution record date start	Oct. 01, 2018
Cash distribution record date end	Dec. 31, 2018
Class T Common Stock [Member]
Schedule Of Stockholders Equity [Line Items]
Common stock daily distribution payable	$ 0.00142
Class W Common Stock [Member]
Schedule Of Stockholders Equity [Line Items]
Common stock daily distribution payable	$ 0.00157