Debt - Debt Extinguishment - Narrative (Details)
$ in Thousands
3 Months Ended 6 Months Ended
Jun. 30, 2015
USD ($)
Property
Jun. 30, 2014
USD ($)
Property
Jun. 30, 2015
USD ($)
Property
Jun. 30, 2014
USD ($)
Property
Debt Instrument [Line Items]        
Net loss on debt extinguishment $ 3,377 $ (64,708) $ 2,147 $ (64,708)
Number of properties disposed of during period | Property 2 3 2 5
CMBS Loans        
Debt Instrument [Line Items]        
Number of properties disposed of during period | Property 5      
Mortgages        
Debt Instrument [Line Items]        
Amount of debt defeasance     $ 336,800 $ 509,800
Weighted average contractual interest rate 5.64% 6.59% 5.64% 6.59%
Net loss on debt extinguishment     $ 2,100 $ 64,700
Reduction of debt     17,500  
Proceeds from sale of properties     $ (14,000)  
Mortgages | CMBS Loans        
Debt Instrument [Line Items]        
Number of properties disposed of during period | Property     4  
Net-lease Mortgage Notes        
Debt Instrument [Line Items]        
Amount of debt defeasance     $ 18,000