Quarterly report pursuant to Section 13 or 15(d)

Debt, Net (Details)

v3.10.0.1
Debt, Net (Details)
 3 Months Ended 9 Months Ended
Oct. 10, 2018
USD ($)
extension
Sep. 30, 2018
USD ($)
Sep. 30, 2017
USD ($)
Sep. 30, 2018
USD ($)
Sep. 30, 2017
USD ($)
Dec. 31, 2017
USD ($)
Debt            
Carrying Value   $ 1,808,030,000   $ 1,808,030,000   $ 1,828,333,000
Interest costs capitalized   1,400,000 $ 1,100,000 4,200,000 $ 4,200,000  
Secured Debt            
Debt            
Carrying Value   168,944,000   168,944,000   163,838,000
Line of Credit | Revolving Credit Facility | Subsequent Event            
Debt            
Number of extensions | extension 2          
Extension option period 6 months          
Maximum borrowing capacity $ 800,000,000          
Aggregate maximum borrowing capacity $ 1,250,000,000          
Extension fee percentage 0.075%          
Line of Credit | Revolving Credit Facility | Minimum | London Interbank Offered Rate (LIBOR) | Subsequent Event            
Debt            
Variable rate, spread (as a percent) 0.775%          
Commitment fee percentage 0.125%          
Line of Credit | Revolving Credit Facility | Maximum | London Interbank Offered Rate (LIBOR) | Subsequent Event            
Debt            
Variable rate, spread (as a percent) 1.45%          
Commitment fee percentage 0.30%          
Loans payable            
Debt            
Deferred financing costs, net   7,600,000   7,600,000   5,000,000
Fixed rate debt | Secured Debt            
Debt            
Carrying Value   148,054,000   148,054,000   150,723,000
Unamortized premium included in carrying value   $ 298,000   $ 298,000   349,000
Weighted average interest rate (as a percent)   4.18%   4.18%    
Fixed rate debt | Secured Debt | Minimum            
Debt            
Interest rate (as a percent)   3.82%   3.82%    
Fixed rate debt | Secured Debt | Maximum            
Debt            
Interest rate (as a percent)   7.87%   7.87%    
Variable-rate debt | Secured Debt            
Debt            
Carrying Value   $ 20,890,000   $ 20,890,000   13,115,000
Weighted average interest rate (as a percent)   4.20%   4.20%    
Variable-rate debt | Secured Debt | Minimum | London Interbank Offered Rate (LIBOR)            
Debt            
Variable rate, spread (as a percent)       1.85%    
Variable-rate debt | Secured Debt | Maximum | London Interbank Offered Rate (LIBOR)            
Debt            
Variable rate, spread (as a percent)       2.35%    
Construction Loan | Secured Debt | London Interbank Offered Rate (LIBOR)            
Debt            
Remaining borrowing capacity   $ 100,700,000   $ 100,700,000    
Revolving Credit Facility            
Debt            
Carrying Value   $ 99,000,000   $ 99,000,000   126,000,000
Weighted average interest rate (as a percent)   3.37%   3.37%    
Revolving Credit Facility | Minimum | London Interbank Offered Rate (LIBOR)            
Debt            
Variable rate, spread (as a percent)       0.875%    
Revolving Credit Facility | Maximum | London Interbank Offered Rate (LIBOR)            
Debt            
Variable rate, spread (as a percent)       1.60%    
Term Loan Facilities            
Debt            
Carrying Value   $ 348,298,000   $ 348,298,000   347,959,000
Weighted average interest rate (as a percent)   3.47%   3.47%    
Aggregate additional borrowing capacity available   $ 350,000,000   $ 350,000,000    
Term Loan Facilities | Minimum | London Interbank Offered Rate (LIBOR)            
Debt            
Variable rate, spread (as a percent)       0.90%    
Term Loan Facilities | Maximum | London Interbank Offered Rate (LIBOR)            
Debt            
Variable rate, spread (as a percent)       1.85%    
3.600% Senior Notes | Unsecured senior notes            
Debt            
Carrying Value   347,876,000   $ 347,876,000   347,551,000
Debt instrument, face amount   $ 350,000,000   $ 350,000,000    
Interest rate (as a percent)   3.60%   3.60%    
Unamortized discount included in carrying value   $ 1,500,000   $ 1,500,000   1,700,000
Effective interest rate on debt (as a percent)   3.70%   3.70%    
5.250% Senior Notes | Unsecured senior notes            
Debt            
Carrying Value   $ 247,011,000   $ 247,011,000   246,645,000
Debt instrument, face amount   $ 250,000,000   $ 250,000,000    
Interest rate (as a percent)   5.25%   5.25%    
Unamortized discount included in carrying value   $ 2,700,000   $ 2,700,000   3,000,000
Effective interest rate on debt (as a percent)   5.49%   5.49%    
3.700% Senior Notes | Unsecured senior notes            
Debt            
Carrying Value   $ 298,690,000   $ 298,690,000   298,322,000
Debt instrument, face amount   $ 300,000,000   $ 300,000,000    
Interest rate (as a percent)   3.70%   3.70%    
Unamortized discount included in carrying value   $ 1,000,000   $ 1,000,000   1,300,000
Effective interest rate on debt (as a percent)   3.85%   3.85%    
5.000% Senior Notes | Unsecured senior notes            
Debt            
Carrying Value   $ 297,013,000   $ 297,013,000   296,731,000
Debt instrument, face amount   $ 300,000,000   $ 300,000,000    
Interest rate (as a percent)   5.00%   5.00%    
Unamortized discount included in carrying value   $ 2,500,000   $ 2,500,000   2,700,000
Effective interest rate on debt (as a percent)   5.15%   5.15%    
Unsecured notes payable            
Debt            
Carrying Value   $ 1,198,000   $ 1,198,000   1,287,000
Interest rate (as a percent)   0.00%   0.00%    
Unamortized discount included in carrying value   $ 313,000   $ 313,000   $ 373,000