Related Party Transactions and Arrangements - Property Management and Servicing Agreement (Details) - USD ($)
$ in Thousands
3 Months Ended
May 20, 2014
Mar. 31, 2019
Mar. 31, 2018
Dec. 31, 2018
Related Party Transaction [Line Items]        
Related party fee income   $ 6,927 $ 0  
Affiliated Entity | Property Management        
Related Party Transaction [Line Items]        
Annual management fees rate 0.25%      
Related party fee income   1,500    
Affiliated Entity | Special Servicing Fees        
Related Party Transaction [Line Items]        
Annual management fees rate 0.75%      
Related party fee income   400    
Affiliated Entity | Property Management and Servicing Agreement        
Related Party Transaction [Line Items]        
Due from related parties   $ 500   $ 500