Fair Value of Financial Instruments (Tables)

9 Months Ended

Sep. 30, 2011

Fair Value of Financial Instruments [Abstract]

Schedule of financial instruments with fair values different from their carrying amount

	September 30, 2011					December 31, 2010
	Carrying			Fair		Carrying			Fair
	Amount			Value		Amount			Value
Mortgage payable, net of discounts	$	491,867		$	506,042	$	711,789		$	726,348
Unsecured notes payable, net of discounts	$	1,572,750		$	1,610,233	$	1,274,047		$	1,338,743
Variable rate debt instruments	$	427,610		$	416,089	$	444,610		$	432,556
Notes receivable	$	32,407	(a)	$	32,309	$	31,216	(a)	$	28,921

(a) For purposes of this disclosure, one of the notes is presented gross of the deferred gain of $12.9 million arising from the sale of two properties in 2009 accounted for under the accounting standard for installment sales.