Quarterly report pursuant to Section 13 or 15(d)

Unsecured Revolving Credit Facility (Narrative) (Details)

v2.4.0.6
Unsecured Revolving Credit Facility (Narrative) (Details) (USD $)
3 Months Ended
Mar. 31, 2013
entity
Dec. 31, 2012
Line Of Credit Facility By Category [Line Items]    
Number of lending institutions 20  
Borrowing capacity under the credit facility $ 600,000,000  
Expandable borrowing capacity under the credit facility 1,000,000,000  
Credit facility maturity date Oct. 01, 2015  
Credit facility, extension period 1 year  
Credit facility fee, basis point 0.20%  
Line of credit facility, bid feature, current borrowing capacity 300,000,000  
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, the maximum amount of secured indebtedness, the minimum amount of tangible net worth, the minimum amount of fixed charge coverage, the maximum amount of unsecured indebtedness, the minimum amount of unencumbered property interest coverage and certain investment limitations.  
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.  
Outstanding borrowings under the facility 92,000,000 0
Money Market Loan [Member]
   
Line Of Credit Facility By Category [Line Items]    
Borrowing capacity under the credit facility 75,000,000  
Outstanding borrowings under the facility $ 0 $ 0
Maximum [Member] | Money Market Loan [Member]
   
Line Of Credit Facility By Category [Line Items]    
Maturity period of the unsecured borrowing 30 days