Debt - CMBS - Narrative (Details)
$ in Thousands
9 Months Ended
Sep. 30, 2016
USD ($)
Property
Loan
loan
Dec. 31, 2015
USD ($)
Debt Instrument [Line Items]    
Number of properties securing borrowings | Property 75  
Unamortized deferred financing costs $ 38,812 $ 41,577
Weighted Average    
Debt Instrument [Line Items]    
Stated interest rates 4.34%  
CMBS - fixed-rate | Weighted Average    
Debt Instrument [Line Items]    
Stated interest rates 5.63%  
CMBS Loans    
Debt Instrument [Line Items]    
Unamortized deferred financing costs $ 4,900 $ 5,500
CMBS Loans | CMBS - fixed-rate    
Debt Instrument [Line Items]    
Number of loans secured by mortgage on leased properties and related assets | loan 30  
Number of properties securing borrowings | Property 139  
Number of loans in default | Loan 1  
Number of properties securing loans | Property 3  
Debt default amount $ 28,600  
Interest added to principal 8,800  
Restricted cash $ 10,500  
CMBS Loans | CMBS - fixed-rate | Minimum    
Debt Instrument [Line Items]    
Stated interest rates 3.90%  
Default interest rate 9.85%  
CMBS Loans | CMBS - fixed-rate | Maximum    
Debt Instrument [Line Items]    
Stated interest rates 6.522%  
CMBS Loans | CMBS - fixed-rate | Weighted Average    
Debt Instrument [Line Items]    
Stated interest rates 5.91%