Quarterly report pursuant to Section 13 or 15(d)

Unsecured Revolving Credit Facility (Narrative) (Details)

v3.5.0.2
Unsecured Revolving Credit Facility (Narrative) (Details)
$ in Thousands
 6 Months Ended
Jun. 30, 2016
USD ($)
item
entity
Dec. 31, 2015
USD ($)
Line of Credit Facility [Line Items]    
Outstanding borrowings under the facility $ 75,000 $ 155,000
Unsecured Revolving Credit Facility [Member]    
Line of Credit Facility [Line Items]    
Number of lending institutions | entity 17  
Borrowing capacity under the credit facility $ 600,000  
Expandable borrowing capacity under the credit facility $ 1,000,000  
Credit facility maturity date Jul. 01, 2017  
Number of extension options | item 2  
Credit facility, extension period 6 months  
Line of credit facility, bid feature, current borrowing capacity $ 300,000  
Terms of the unsecured facility The terms of the unsecured facility include certain restrictions and covenants which limit, among other things the incurrence of additional indebtedness, the incurrence of liens and the disposition of real estate properties (to the extent that: (i) such property dispositions cause the Company to default on any of the financial ratios of the facility described below, or (ii) the property dispositions are completed while the Company is under an event of default under the facility, unless, under certain circumstances, such disposition is being carried out to cure such default), and which require compliance with financial ratios relating to the maximum leverage ratio (60 percent), the maximum amount of secured indebtedness (40 percent), the minimum amount of fixed charge coverage (1.5 times), the maximum amount of unsecured indebtedness (60 percent), the minimum amount of unencumbered property interest coverage (2.0 times) and certain investment limitations (generally 15 percent of total capitalization).  
Terms of dividend restriction If an event of default has occurred and is continuing, the Company will not make any excess distributions except to enable the Company to continue to qualify as a REIT under the Code. The Company was in compliance with its debt covenants under its revolving credit facility as of June 30, 2016.  
Outstanding borrowings under the facility $ 75,000 $ 155,000
Unsecured Revolving Credit Facility Extension 1 [Member]    
Line of Credit Facility [Line Items]    
Credit facility extension fee, basis points 0.075%  
Unsecured Revolving Credit Facility Extension 2 [Member]    
Line of Credit Facility [Line Items]    
Credit facility extension fee, basis points 0.075%  
Minimum [Member] | Unsecured Revolving Credit Facility [Member]    
Line of Credit Facility [Line Items]    
Fixed charge coverage ratio | item 1.5  
Unencumbered property interest coverage | item 2.0  
Maximum [Member] | Unsecured Revolving Credit Facility [Member]    
Line of Credit Facility [Line Items]    
Leverage ratio 60.00%  
Secured indebtedness 40.00%  
Unsecured indebtedness 60.00%  
Investment limitations as a percentage of total capitalization 15.00%