Annual report pursuant to Section 13 and 15(d)

Unsecured Revolving Credit Facility (Narrative) (Details)

v2.4.0.6
Unsecured Revolving Credit Facility (Narrative) (Details) (USD $)
 12 Months Ended 0 Months Ended 12 Months Ended
Dec. 31, 2012
entity
Dec. 31, 2011
Oct. 20, 2011
Previous Credit Facility [Member]
Dec. 31, 2012
Money Market Loan [Member]
Dec. 31, 2011
Money Market Loan [Member]
Dec. 31, 2012
Maximum [Member]
Money Market Loan [Member]
Line Of Credit Facility By Category [Line Items]            
Number of lending institutions 20          
Borrowing capacity under the credit facility $ 600,000,000   $ 775,000,000 $ 75,000,000    
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   $ 55,500,000   $ 0 $ 0  
Interest rate on outstanding borrowings     LIBOR plus 55      
Spread over LIBOR     0.55%      
Maturity period of the unsecured borrowing           30 days