Mortgages, Loans Payable And Other Obligations (Narrative) (Details) (USD $) | 9 Months Ended | ||
|---|---|---|---|
Sep. 30, 2011 | Sep. 30, 2010 | Dec. 31, 2010 | |
| Number Of Properties With Encumbered Company Mortgages | 32 | ||
| Book value of the encumbered property | $ 957,498,000 | ||
| Cash paid for interest | 99,089,000 | 127,257,000 | |
| Interest capitalized | 875,400 | 1,327,000 | |
| Total indebtedness | 1,886,500,000 | 2,089,494,000 | |
| Weighted average interest rate | 6.52% | 5.97% | |
Revolving Credit Facility Borrowings And Other Variable Rate Mortgage Debt [Member] | |||
| Total indebtedness | 38,000,000 | 239,000,000 | |
| Weighted average rate of variable rate mortgage debt | 1.38% | 0.90% | |
Fixed Rate Debt And Other Obligations [Member] | |||
| Total indebtedness | $ 1,848,500,000 | $ 1,850,494,000 | |
| Weighted average interest rate of the indebtedness | 6.63% | 6.62% | |