| Mortgages, Loans Payable And Other Obligations (Narrative) (Details) (USD $) | 9 Months Ended | ||
|---|---|---|---|
| Sep. 30, 2014
 property | Sep. 30, 2013 | Dec. 31, 2013 | |
| Debt Instrument [Line Items] | |||
| Number of properties with encumbered company mortgages | 30 | ||
| Book value of encumbered properties | $ 982,000,000 | ||
| Cash paid for interest | 92,096,000 | 97,284,000 | |
| Interest capitalized | 10,650,000 | 10,262,000 | |
| Total indebtedness | 2,238,641,000 | 2,362,766,000 | |
| Total indebtedness, weighted average interest rate | 5.62% | 5.62% | |
| Revolving Credit Facility Borrowing And Other Variable Rate Mortgage Debt [Member] | |||
| Debt Instrument [Line Items] | |||
| Total indebtedness | 195,426,000 | 80,228,000 | |
| Total indebtedness, weighted average interest rate | 3.86% | 2.74% | |
| Fixed Rate Debt And Other Obligations [Member] | |||
| Debt Instrument [Line Items] | |||
| Total indebtedness | 2,043,215,000 | 2,282,538,000 | |
| Total indebtedness, weighted average interest rate | 5.78% | 5.72% | |
| Unconsolidated Joint Venture [Member] | |||
| Debt Instrument [Line Items] | |||
| Interest capitalized | $ 3,284,000 | $ 980,000 | |
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- Definition Carrying Value of the Mortgaged Property No definition available. 
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- Definition Number Of Properties With Encumbered Company Mortgages No definition available. 
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- Details 
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- Definition Amount of interest capitalized during the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition The amount of cash paid for interest during the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition Carrying amount of long-term debt, net of unamortized discount or premium, including current and noncurrent amounts. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition Weighted average interest rate of long-term debt outstanding. No definition available. 
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