Fair Value Measurements (Tables)

9 Months Ended

Sep. 30, 2016

Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]

Schedule of Fair Values of Financial Assets and Liabilities by Levels [Table Text Block]

The tables below aggregate the fair values of these financial assets and liabilities by their levels in the fair value hierarchy as of September 30, 2016 and December 31, 2015, respectively.

(Amounts in thousands)		As of September 30, 2016
		Total		Level 1		Level 2		Level 3
Marketable securities		$	198,165	$	198,165	$	-	$	-
Real estate fund investments			519,386		-		-		519,386
Deferred compensation plan assets (included in other assets)			118,359		61,444		-		56,915
Interest rate swap (included in other assets)			3,064		-		3,064		-
	Total assets	$	838,974	$	259,609	$	3,064	$	576,301

Mandatorily redeemable instruments (included in other liabilities)		$	50,561	$	50,561	$	-	$	-
Interest rate swaps (included in other liabilities)			23,646		-		23,646		-
	Total liabilities	$	74,207	$	50,561	$	23,646	$	-

(Amounts in thousands)		As of December 31, 2015
		Total		Level 1		Level 2		Level 3
Marketable securities		$	150,997	$	150,997	$	-	$	-
Real estate fund investments			574,761		-		-		574,761
Deferred compensation plan assets (included in other assets)			117,475		58,289		-		59,186
	Total assets	$	843,233	$	209,286	$	-	$	633,947

Mandatorily redeemable instruments (included in other liabilities)		$	50,561	$	50,561	$	-	$	-
Interest rate swaps (included in other liabilities)			19,600		-		19,600		-
	Total liabilities	$	70,161	$	50,561	$	19,600	$	-

Schedule Of Carrying Amounts And Fair Values Of Financial Instruments [Table Text Block]

The table below summarizes the carrying amounts and fair value of these financial instruments as of September 30, 2016 and December 31, 2015.

(Amounts in thousands)		As of September 30, 2016					As of December 31, 2015
		Carrying			Fair		Carrying			Fair
		Amount			Value		Amount			Value
Cash equivalents		$	1,003,149		$	1,003,000	$	1,295,980		$	1,296,000
Debt:
	Mortgages payable	$	9,968,499		$	9,371,000	$	9,614,838		$	9,306,000
	Senior unsecured notes		850,000			896,000		850,000			868,000
	Unsecured term loan		375,000			375,000		187,500			188,000
	Unsecured revolving credit facilities		115,630			116,000		550,000			550,000
	Total	$	11,309,129	⁽¹⁾	$	10,758,000	$	11,202,338	⁽¹⁾	$	10,912,000


(1)	Excludes $108,891 and $111,328 of deferred financing costs, net and other as of September 30, 2016 and December 31, 2015, respectively.

Real Estate Fund [Member]

Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]

Fair Value Inputs, Assets, Quantitative Information [Table Text Block]

Significant unobservable quantitative inputs in the table below were utilized in determining the fair value of these real estate fund investments at September 30, 2016 and December 31, 2015.

			Weighted Average
	Range		(based on fair value of investments)
Unobservable Quantitative Input	September 30, 2016	December 31, 2015	September 30, 2016	December 31, 2015
Discount rates	12.0% to 14.9%	12.0% to 14.9%	13.7%	13.6%
Terminal capitalization rates	4.7% to 5.8%	4.8% to 6.1%	5.4%	5.5%

Summary of Changes in Level 3 Plan Assets [Table Text Block]

The table below summarizes the changes in the fair value of real estate fund investments that are classified as Level 3, for the three and nine months ended September 30, 2016 and 2015.

(Amounts in thousands)	For the Three Months Ended				For the Nine Months Ended
	September 30,				September 30,
		2016		2015	2016		2015
Beginning balance	$	524,150	$	565,976	$	574,761	$	513,973
Purchases		-		11		-		95,011
Dispositions / distributions		-		(8,029)		(71,888)		(91,450)
Net unrealized (losses) gains		(4,764)		(2,544)		16,091		37,001
Net realized (losses) gains		-		(907)		422		1,405
Other, net		-		907		-		(526)
Ending balance	$	519,386	$	555,414	$	519,386	$	555,414

Deferred Compensation Plan Assets [Member]

Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]

Summary of Changes in Level 3 Plan Assets [Table Text Block]

The table below summarizes the changes in the fair value of deferred compensation plan assets that are classified as Level 3, for the three and nine months ended September 30, 2016 and 2015.

(Amounts in thousands)	For the Three Months Ended				For the Nine Months Ended
	September 30,				September 30,
		2016		2015	2016		2015
Beginning balance	$	60,140	$	67,668	$	59,186	$	63,315
Purchases		1,251		2,153		3,523		8,384
Sales		(3,737)		(171)		(5,888)		(5,264)
Realized and unrealized (losses) gains		(1,055)		(1,466)		(743)		1,256
Other, net		316		24		837		517
Ending balance	$	56,915	$	68,208	$	56,915	$	68,208