Finance Receivables - Narratives (Details)
$ in Thousands
12 Months Ended
Nov. 04, 2016
USD ($)
Apr. 08, 2016
USD ($)
property
Feb. 10, 2016
USD ($)
Jun. 26, 2015
USD ($)
property
Feb. 03, 2015
USD ($)
Jan. 08, 2015
USD ($)
Dec. 14, 2010
USD ($)
Dec. 31, 2016
USD ($)
Dec. 31, 2015
USD ($)
Dec. 31, 2014
USD ($)
Accounts, Notes, Loans and Financing Receivable                    
Effects of foreign currency translation on balance sheet item               $ (18,785) $ (81,037) $ (93,401)
Net investments in direct financing leases               508,392 495,564  
Acquisition costs, expensed               7,157 651 $ 5,169
Financing receivable               539,892 $ 539,608  
China Alliance Properties Limited                    
Accounts, Notes, Loans and Financing Receivable                    
Notes receivable interest rate             11.00%      
Financing receivable             $ 40,000      
127 West 23rd Investors, LLC                    
Accounts, Notes, Loans and Financing Receivable                    
Acquisition costs, expensed         $ 100          
Notes receivable interest rate         7.00%          
Proceeds from collection of loans receivable $ 12,600                  
Financing receivable         $ 12,600          
1185 Broadway LLC                    
Accounts, Notes, Loans and Financing Receivable                    
Acquisition costs, expensed           $ 300        
Notes receivable interest rate           10.00%        
Financing receivable           $ 30,000   31,500    
Notes receivable maturity date           Jan. 08, 2017        
Industrial Facility in Houston, TX                    
Accounts, Notes, Loans and Financing Receivable                    
Net investments in direct financing leases     $ 4,200              
Acquisition Costs, Period Cost     $ 300              
Facilities in Ohio, North Carolina, Pennsylvania and Missouri                    
Accounts, Notes, Loans and Financing Receivable                    
Net investments in direct financing leases   $ 12,000                
Number of properties acquired | property   6                
Acquisition Costs, Period Cost   $ 500                
Retail Facilities                    
Accounts, Notes, Loans and Financing Receivable                    
Net investments in direct financing leases       $ 18,600            
Number of properties acquired | property       2            
Acquisition Costs, Period Cost       $ 1,200            
Net investments in direct financing lease                    
Accounts, Notes, Loans and Financing Receivable                    
Effects of foreign currency translation on balance sheet item               $ (4,700)