Related Party Transactions - Schedule of Fees Waived or Expense Supported by the Advisor and Reimbursements to the Advisor by the Company (Detail) - USD ($)	3 Months Ended	6 Months Ended
Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Related Party Transaction [Line Items]
Total expense support from Advisor	$ 372,773	$ 0	$ 690,969	$ 0
Advisor \| Expense Support Agreement
Related Party Transaction [Line Items]
Expense support payment obligations incurred, asset management fees	0	0	0	0
Expense support payment obligations incurred, other expense support	372,773	0	690,969	0
Total expense support from Advisor	$ 372,773	$ 0	$ 690,969	$ 0

The amount of expense support from the advisor that helps fund certain of the company's fees and expenses (as defined by the expense support agreement) by deferring or waiving them for the period. Also includes any amounts of expense support that has been repaid by the company to the advisor for previously deferred fees and expenses.

No definition available.

Name:	ck0001625941_ExpenseSupportReimbursementFromRepaymentToAdvisor
Namespace Prefix:	ck0001625941_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration