Commitments and Contingencies - Additional Information (Detail) - USD ($)
1 Months Ended 9 Months Ended
Jan. 09, 2017
Oct. 31, 2017
Jul. 31, 2017
Apr. 30, 2017
Oct. 31, 2016
Jul. 31, 2016
Apr. 30, 2016
Sep. 30, 2017
Sep. 30, 2016
Apr. 13, 2017
Commitments and Contingencies [Line Items]                    
Redemptions of common stock, value               $ 116    
Distribution Reinvestment Plan                    
Commitments and Contingencies [Line Items]                    
Amendment, suspension or termination period for distribution reinvestment Plan               10 days    
Sales commissions, dealer manager fee, or stockholder servicing fee payable               $ 0    
Share Redemption Program                    
Commitments and Contingencies [Line Items]                    
Amendment, suspension or termination period of share               30 days    
Maximum weighted-average number of shares outstanding percentage               5.00%    
Redemptions of common stock (in shares)               160,000 110,000  
Redemptions of common stock, value     $ 460,000 $ 380,000 $ 370,000 $ 160,000 $ 530,000 $ 1,500,000 $ 1,100,000  
Share Redemption Program | Subsequent Event                    
Commitments and Contingencies [Line Items]                    
Redemptions of common stock, value   $ 650,000                
Share Redemption Program | Minimum                    
Commitments and Contingencies [Line Items]                    
Shareholders share holding period               1 year    
Operating Partnership Redemption Rights                    
Commitments and Contingencies [Line Items]                    
Number of shares issuable upon conversion of partnership units               1    
Requisite minimum outstanding period for conversion eligibility               1 year    
Class A and Class T Common Stock | Distribution Reinvestment Plan                    
Commitments and Contingencies [Line Items]                    
Estimated value per share under distribution reinvestment plan                   $ 10.22
Class A Common stock | Distribution Reinvestment Plan                    
Commitments and Contingencies [Line Items]                    
Shares issued pursuant to distribution reinvestment plan 1,100,000             1,000,000    
Class T Common stock | Distribution Reinvestment Plan                    
Commitments and Contingencies [Line Items]                    
Shares issued pursuant to distribution reinvestment plan 100,000             200,000