Risk Management and Use of Derivative Financial Instruments - Interest Rate Swap and Swaptions Summary (Details)
€ in Thousands, £ in Thousands, $ in Thousands
Dec. 31, 2016
USD ($)
instrument
Dec. 31, 2016
EUR (€)
instrument
Dec. 31, 2016
GBP (£)
instrument
Derivative      
Fair value $ (5,787)    
Cash Flow Hedging | Interest rate swap | USD      
Derivative      
Derivative number of instruments | instrument 14 14 14
Derivative notional amount $ 231,481    
Fair value $ (4,809)    
Cash Flow Hedging | Interest rate swap | Euro      
Derivative      
Derivative number of instruments | instrument 6 6 6
Derivative notional amount | €   € 63,585  
Fair value $ (1,148)    
Cash Flow Hedging | Interest rate cap | Euro      
Derivative      
Derivative number of instruments | instrument 1 1 1
Derivative notional amount | €   € 12,324  
Fair value $ 38    
Cash Flow Hedging | Interest rate cap | GBP      
Derivative      
Derivative number of instruments | instrument 1 1 1
Derivative notional amount | £     £ 6,394
Fair value $ 41    
Not designated | Swaption | USD      
Derivative      
Derivative number of instruments | instrument 1 1 1
Derivative notional amount $ 13,230    
Fair value $ 264    
Not designated | Swap | Euro      
Derivative      
Derivative number of instruments | instrument 1 1 1
Derivative notional amount | €   € 4,960  
Fair value $ (173)