Mortgage Notes Payable: (Details 2) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Future maturities of mortgage notes payable
Debt premium, net	$ 29,864	$ 7,841
Total	4,437,343	3,328,438
Mortgage notes payable
Future maturities of mortgage notes payable
2013	511,366
2014	231,183
2015	646,787
2016	617,266
2017	128,890
Thereafter	2,271,987
Long term debt including debt premium	4,407,479
Debt premium, net	29,864
Total	$ 4,437,343

Including current and noncurrent portions, aggregate carrying amount of long-term borrowings as of the balance sheet date before deducting unamortized discount or premiums (if any). May include notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt, which had initial maturities beyond one year or beyond the normal operating cycle, if longer.

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