v2.4.0.6
Borrowing Arrangements (Details 4) (USD $)
 12 Months Ended
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2010
Dec. 31, 2009
Dec. 31, 2008
Scheduled maturities of borrowing arrangements and other provisions excluding capital lease obligations          
2013 $ 553,227,000 [1]        
2014 339,668,000        
2015 1,652,672,000        
2016 442,518,000        
2017 942,158,000        
Thereafter 4,256,072,000 [1],[2]        
Total maturities 8,186,315,000 6,180,443,000      
Unrestricted cash and cash equivalents 67,908,000 45,807,000 21,812,000 107,397,000 107,397,000
Amount outstanding, net of cash and cash equivalents 472,800,000        
Interest rate (as a percent) 9.00%   7.125%    
Minimum percentage of total unencumbered assets as a percentage of unsecured debt required to be maintained (as a percent) 150.00%        
Line of Credit
          
Scheduled maturities of borrowing arrangements and other provisions excluding capital lease obligations          
Total maturities 540,727,000 455,578,000      
Mortgage loans
          
Scheduled maturities of borrowing arrangements and other provisions excluding capital lease obligations          
Total maturities 23,200,000        
6.90% Senior Notes due 2037
          
Scheduled maturities of borrowing arrangements and other provisions excluding capital lease obligations          
Thereafter 52,400,000        
Interest rate (as a percent) 6.90%        
6.59% senior notes due 2038
          
Scheduled maturities of borrowing arrangements and other provisions excluding capital lease obligations          
Thereafter 23,000,000        
Interest rate (as a percent) 6.59%        
Principal Amount Due at Maturity
          
Scheduled maturities of borrowing arrangements and other provisions excluding capital lease obligations          
2013 501,029,000 [1]        
2014 291,708,000        
2015 1,073,272,000        
2016 410,917,000        
2017 922,731,000        
Thereafter 4,098,227,000 [1],[2]        
Total maturities 7,297,884,000        
Unsecured Revolving Credit Facility
          
Scheduled maturities of borrowing arrangements and other provisions excluding capital lease obligations          
2013 0 [1],[3]        
2014 0 [3]        
2015 540,727,000 [3]        
2016 0 [3]        
2017 0 [3]        
Thereafter 0 [1],[2],[3]        
Total maturities 540,727,000 [3]        
Scheduled Periodic Amortization
          
Scheduled maturities of borrowing arrangements and other provisions excluding capital lease obligations          
2013 52,198,000 [1]        
2014 47,960,000        
2015 38,673,000        
2016 31,601,000        
2017 19,427,000        
Thereafter 157,845,000 [1],[2]        
Total maturities 347,704,000        
Line of Credit
          
Scheduled maturities of borrowing arrangements and other provisions excluding capital lease obligations          
Unrestricted cash and cash equivalents $ 67,900,000        
[1] Excludes debt related to one property classified as held for sale as of December 31, 2012. The total mortgage debt for this property as of December 31, 2012 was $23.2 million and is scheduled to mature in 2013.
[2] Includes $52.4 million aggregate principal amount of our 6.90% senior notes due 2037 that are subject to repurchase, at the option of the holders, on October 1 in each of the years 2017 and 2027, and $23.0 million aggregate principal amount of our 6.59% senior notes due 2038 that are subject to repurchase, at the option of the holders, on July 7 in each of the years 2013, 2018, 2023 and 2028.
[3] At December 31, 2012, we had $67.9 million of unrestricted cash and cash equivalents, for $472.8 million of net borrowings outstanding under our unsecured revolving credit facility.