Quarterly report pursuant to Section 13 or 15(d)

Subsequent Events - Additional Information (Detail)

v3.8.0.1
Subsequent Events - Additional Information (Detail)
$ / shares in Units, $ in Thousands
 1 Months Ended 9 Months Ended
Nov. 06, 2017
USD ($)
$ / shares
shares
Oct. 27, 2017
USD ($)
a
Jun. 26, 2017
shares
Sep. 30, 2017
USD ($)
Sep. 30, 2016
USD ($)
Subsequent Event [Line Items]          
Stock Issued During Period, Value, Issued for Services       $ 2 $ 2
Over-Allotment Option [Member]          
Subsequent Event [Line Items]          
Stock Issued During Period, Shares, New Issues | shares     825,000    
Subsequent Event [Member] | Perpetual Preferred Offering [Member] | Series A Preferred Stock [Member]          
Subsequent Event [Line Items]          
Stock Issued During Period, Shares, New Issues | shares 1,000,000        
Shares Issued, Price Per Share | $ / shares $ 25.00        
Stock Issued During Period, Value, Issued for Services $ 25,000        
Preferred Stock, Dividend Rate, Percentage 9.375%        
Subsequent Event [Member] | Over-Allotment Option [Member] | Series A Preferred Stock [Member]          
Subsequent Event [Line Items]          
Stock Issued During Period, Shares, Share-based Compensation, Gross | shares 150,000        
Subsequent Event [Member] | Mustang [Member]          
Subsequent Event [Line Items]          
Land Subject to Ground Leases | a   27,043      
Operating Leases, Rent Expense, Sublease Rentals   $ 3,600      
Land Improvements   3,500      
Security Deposit   800      
Increase (Decrease) in Security Deposits   1,300      
Subsequent Event [Member] | Mustang [Member] | Cash [Member]          
Subsequent Event [Line Items]          
Security Deposit   300      
Increase (Decrease) in Security Deposits   300      
Subsequent Event [Member] | Mustang [Member] | Letter of Credit [Member]          
Subsequent Event [Line Items]          
Security Deposit   500      
Increase (Decrease) in Security Deposits   $ 1,000