Mortgage and Other Indebtedness, Derivative Instrument Risk (Details 5) (USD $) In Thousands, unless otherwise specified	6 Months Ended		3 Months Ended			3 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012 Interest Expense [Member]	Jun. 30, 2011 Interest Expense [Member]	Jun. 30, 2012 Other Comprehensive Income (Loss) [Member]	Jun. 30, 2012 Interest Rate Contract [Member]	Jun. 30, 2011 Interest Rate Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain Recognized in OCI/L (Effective Portion)	$ (481)	$ (2,072)				$ (764)	$ (2,634)
Loss Recognized in Earnings (Effective Portion)	(1,129)	(658)	(567)	(636)
Gain Recognized in Earnings (Ineffective Portion)	0	0	0	0
Reclassification of losses currently reported in accumulated other comprehensive income to interest expense in the next twelve months					$ 2,149