Disclosure About Fair Value of Financial Instruments - Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis (Details) (USD $)	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2008
Assets [Abstract]
Marketable securities of non-qualified deferred compensation plan (in prepaid expenses and other assets)	$ 3,149,000	$ 3,479,000	$ 6,100,000
Tax increment financing bond (in prepaid expenses and other assets)	14,788,000	15,699,000
Impaired real estate assets	12,767,000
Total Assets	30,704,000	19,178,000
Noncontrolling Interests in the Operating Partnership	110,655,000	120,838,000
Liability [Abstract]
Interest rate swaps	2,202,000
Non-qualified deferred compensation obligation (in accounts payable, accrued expenses and other liabilities)	3,149,000	4,091,000	6,898,000	6,522,000
Total Liabilities	5,351,000
Level 1 [Member]
Assets [Abstract]
Marketable securities of non-qualified deferred compensation plan (in prepaid expenses and other assets)	3,149,000	3,479,000
Tax increment financing bond (in prepaid expenses and other assets)	0	0
Impaired real estate assets	0
Total Assets	3,149,000	3,479,000
Noncontrolling Interests in the Operating Partnership	110,655,000	120,838,000
Liability [Abstract]
Interest rate swaps	0
Non-qualified deferred compensation obligation (in accounts payable, accrued expenses and other liabilities)	3,149,000	4,091,000
Total Liabilities	3,149,000
Level 2 [Member]
Assets [Abstract]
Marketable securities of non-qualified deferred compensation plan (in prepaid expenses and other assets)	0
Tax increment financing bond (in prepaid expenses and other assets)	0
Impaired real estate assets	0
Total Assets	0
Noncontrolling Interests in the Operating Partnership	0
Liability [Abstract]
Interest rate swaps	2,202,000
Non-qualified deferred compensation obligation (in accounts payable, accrued expenses and other liabilities)	0
Total Liabilities	2,202,000
Level 3 [Member]
Assets [Abstract]
Marketable securities of non-qualified deferred compensation plan (in prepaid expenses and other assets)	0	0
Tax increment financing bond (in prepaid expenses and other assets)	14,788,000	15,699,000
Impaired real estate assets	12,767,000
Total Assets	27,555,000	15,699,000
Noncontrolling Interests in the Operating Partnership	0	0
Liability [Abstract]
Interest rate swaps	0
Non-qualified deferred compensation obligation (in accounts payable, accrued expenses and other liabilities)	0	0
Total Liabilities	$ 0