Stockholders' Equity - Summary of Changes in Shares Outstanding and Aggregate Par Value of Outstanding Shares for Each Class of Common Stock (Detail) - USD ($)	1 Months Ended	3 Months Ended		6 Months Ended
	Dec. 31, 2016	Jun. 30, 2017	Mar. 31, 2017	Jun. 30, 2017	Nov. 30, 2014
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance			$ 2,114,487	$ 2,114,487
Stock dividends, shares		964	946	1,910
Stock dividends		$ 9,623	$ 9,443	$ 19,066
Ending balance	$ 2,114,487	$ 2,118,231		$ 2,118,231
Class T
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance, shares			7,000	7,000
Ending balance, shares	7,000	7,026		7,026
Shares of common stock sold (in shares)	7,000	7,026		7,026
Class W
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance, shares			0	0
Ending balance, shares	0	0		0
Shares of common stock sold (in shares)	0	0		0
Class I
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance, shares			248,349	248,349
Ending balance, shares	248,349	250,779		250,779
Shares of common stock sold (in shares)	248,349	250,779		250,779
Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance, shares			255,349	255,349
Beginning balance			$ 2,553	$ 2,553
Issuance of common stock, DRIP, shares				1,510
Issuance of common stock, DRIP				$ 15
Stock dividends, shares				946
Stock dividends				$ 10
Ending balance, shares	255,349	257,805		257,805
Ending balance	$ 2,553	$ 2,578		$ 2,578
Common Stock | Class T
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance, shares			7,000	7,000
Beginning balance			$ 70	$ 70
Issuance of common stock, DRIP, shares				0
Issuance of common stock, DRIP				$ 0
Stock dividends, shares				26
Stock dividends				$ 0
Ending balance, shares	7,000	7,026		7,026
Ending balance	$ 70	$ 70		$ 70
Common Stock | Class W
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance, shares			0	0
Beginning balance			$ 0	$ 0
Issuance of common stock, DRIP, shares				0
Issuance of common stock, DRIP				$ 0
Stock dividends, shares				0
Stock dividends				$ 0
Ending balance, shares	0	0		0
Ending balance	$ 0	$ 0		$ 0
Common Stock | Class I
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance, shares			248,349	248,349
Beginning balance			$ 2,483	$ 2,483
Issuance of common stock, DRIP, shares				1,510
Issuance of common stock, DRIP				$ 15
Stock dividends, shares				920
Stock dividends				$ 10
Ending balance, shares	248,349	250,779		250,779
Ending balance	$ 2,483	$ 2,508		$ 2,508
Common Stock | Class I | Affiliated Entity | BCI IV Advisors LLC (the Advisor)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares of common stock sold (in shares)					20,000