Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2012

Fair Value Measurements [Abstract]

Quantitative Disclosure of The Fair Value For Each Major Category Of Assets And Liabilities

		Fair Value Measurements at June 30, 2012
Description		Using Quoted Prices in Active Markets for Identical Assets (Level 1)			Using Significant Other Observable Inputs (Level 2)				Using Significant Other Unobservable Inputs (Level 3)
Available-for-sale real estate equity securities	$		301,945	$		0		$		0
Real estate related bonds			0			21,516				0
Total assets	$		301,945	$		21,516		$		0
Derivative interest rate instruments	$		0	$		(1,735	)	$		0
Total liabilities	$		0	$		(1,735	)	$		0

		Fair Value Measurements at December 31, 2011
Description		Using Quoted Prices in Active Markets for Identical Assets (Level 1)			Using Significant Other Observable Inputs (Level 2)				Using Significant Other Unobservable Inputs (Level 3)
Available-for-sale real estate equity securities	$		274,274	$		0		$		0
Real estate related bonds			0			15,091				0
Total assets	$		274,274	$		15,091		$		0
Derivative interest rate instruments	$		0	$		(2,284	)	$		0
Total liabilities	$		0	$		(2,284	)	$		0

Assets Measured at Fair Value on Non-Recurring Basis

	For the three months ended June 30, 2012				For the three months ended June 30, 2011
	Fair Value Measurements Using Significant Unobservable Inputs (Level 3)		Total Impairment Losses		Fair Value Measurements Using Significant Unobservable Inputs (Level 3)		Total Impairment Losses
Investment properties		80,871		17,458		157,059		30,208
Total		80,871		17,458		157,059		30,208

		For the six months ended June 30, 2012						For the six months  ended June 30, 2011
		Fair Value Measurements Using Significant Unobservable Inputs (Level 3)			Total Impairment Losses			Fair Value Measurements Using Significant Unobservable Inputs (Level 3)			Total Impairment Losses
Investment properties	$		223,508	$		27,887	$		224,309	$		58,175
Investment in unconsolidated entity	$		16,914	$		4,200	$		0	$		0
Total	$		240,422	$		32,087	$		224,309	$		58,175

Fair Value of Financial Instruments Presented at Carrying Values

		June 30, 2012						December 31, 2011
		Carrying Value			Estimated Fair Value			Carrying Value			Estimated Fair Value
Mortgage and notes payable	$		6,078,271	$		5,937,002	$		5,812,595	$		5,524,022
Margins payable	$		149,979	$		149,979	$		120,858	$		120,858