Annual report pursuant to Section 13 and 15(d)

Debt, Net (Details)

v3.8.0.1
Debt, Net (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Jun. 29, 2015
Debt      
Debt, net $ 1,828,333 $ 1,904,001  
Deferred financing costs, net 1,202 3,128  
Revolving Credit Facility [Member]      
Debt      
Debt, net 126,000 0  
Term Loan Facilities [Member]      
Debt      
Debt, net $ 347,959 547,494  
Weighted average interest rate (as a percent) 2.73%    
Aggregate additional borrowing capacity $ 350,000    
Unsecured notes payable [Member]      
Debt      
Debt, net $ 1,287 1,401  
Stated interest rate (as a percent) 0.00%    
Unamortized discount included in carrying value $ 373 460  
London Interbank Offered Rate (LIBOR) [Member] | Revolving Credit Facility [Member] | Minimum [Member]      
Debt      
Variable rate, spread (as a percent) 0.875%    
London Interbank Offered Rate (LIBOR) [Member] | Revolving Credit Facility [Member] | Maximum [Member]      
Debt      
Variable rate, spread (as a percent) 1.60%    
London Interbank Offered Rate (LIBOR) [Member] | Term Loan Facilities [Member] | Minimum [Member]      
Debt      
Variable rate, spread (as a percent) 0.90%    
London Interbank Offered Rate (LIBOR) [Member] | Term Loan Facilities [Member] | Maximum [Member]      
Debt      
Variable rate, spread (as a percent) 1.85%    
Mortgage and other secured debt [Member]      
Debt      
Debt, net $ 163,838 167,591  
Mortgage and other secured debt [Member] | Fixed rate mortgage loans [Member]      
Debt      
Debt, net 150,723 154,143  
Unamortized premium included in carrying value $ 349 422  
Weighted average interest rate (as a percent) 4.19%    
Mortgage and other secured debt [Member] | Fixed rate mortgage loans [Member] | Minimum [Member]      
Debt      
Stated interest rate (as a percent) 3.82%    
Mortgage and other secured debt [Member] | Fixed rate mortgage loans [Member] | Maximum [Member]      
Debt      
Stated interest rate (as a percent) 7.87%    
Mortgage and other secured debt [Member] | Variable rate secured loans [Member]      
Debt      
Debt, net $ 13,115 13,448  
Stated interest rate (as a percent) 3.21%    
Mortgage and other secured debt [Member] | London Interbank Offered Rate (LIBOR) [Member] | Variable rate secured loans [Member]      
Debt      
Variable rate, spread (as a percent) 1.85%    
Senior Notes [Member] | 3.60% Senior Notes [Member]      
Debt      
Debt, net $ 347,551 347,128  
Stated interest rate (as a percent) 3.60%    
Interest rate on debt (as a percent) 3.70%    
Unamortized discount included in carrying value $ 1,700 2,000  
Senior Notes [Member] | 5.250% Senior Notes [Member]      
Debt      
Debt, net $ 246,645 246,176  
Stated interest rate (as a percent) 5.25%    
Interest rate on debt (as a percent) 5.49%    
Unamortized discount included in carrying value $ 3,000 3,400  
Senior Notes [Member] | 3.70% Senior Notes [Member]      
Debt      
Debt, net $ 298,322 297,843  
Stated interest rate (as a percent) 3.70%    
Interest rate on debt (as a percent) 3.85%    
Unamortized discount included in carrying value $ 1,300 1,700  
Senior Notes [Member] | 5.0% Senior Notes [Member]      
Debt      
Debt, net $ 296,731 296,368  
Stated interest rate (as a percent) 5.00%   5.00%
Interest rate on debt (as a percent) 5.15%    
Unamortized discount included in carrying value $ 2,700 3,000  
Loans Payable [Member]      
Debt      
Deferred financing costs, net $ 5,000 $ 6,100