Mortgage and Other Indebtedness, Derivative Instrument Risk (Details 5) (USD $) In Thousands, unless otherwise specified	9 Months Ended		3 Months Ended			3 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012 Interest Expense [Member]	Sep. 30, 2011 Interest Expense [Member]	Sep. 30, 2012 Other Comprehensive Income (Loss) [Member]	Sep. 30, 2012 Interest Rate Contract [Member]	Sep. 30, 2011 Interest Rate Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Loss Recognized in OCI/L (Effective Portion)	$ (714)	$ (5,466)				$ (234)	$ (3,393)
Loss Recognized in Earnings (Effective Portion)	(1,696)	(1,326)	(567)	(668)
Gain Recognized in Earnings (Ineffective Portion)	0	0	0	0
Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net					$ 2,239