Basis of Presentation and Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2012

Basis Of Presentation And Significant Accounting Policies Tables [Abstract]

Non Cash Impairment And Other Losses [Table Text Block]

(Amounts in thousands)			For the Year Ended December 31,
			2012		2011		2010
Impairment losses:
	Real estate assets	$	107,000	$	-	$	72,500
	Development projects		-		3,040		-
	Condominium units held for sale (see page 140)		2,538		-		30,013
Acquisition related costs and tenant buy-outs			11,248		32,259		6,945
		$	120,786	$	35,299	$	109,458

Reconciliation Of Net Income Attributable To Common Shareholders To Estimated Taxable Income [Table Text Block]

(Amounts in thousands)			For the Year Ended December 31,
			2012		2011		2010
Net income attributable to common shareholders		$	549,271	$	601,771	$	596,731
Book to tax differences (unaudited):
	Depreciation and amortization		205,155		225,802		216,473
	Impairment losses on marketable equity securities		211,328		-		-
	Straight-line rent adjustments		(64,679)		(38,800)		(70,606)
	Earnings of partially owned entities		(60,049)		(96,178)		(62,315)
	Stock options		(28,701)		(27,697)		(48,399)
	Sale of real estate		(123,905)		(18,766)		12,899
	Derivatives		71,228		(12,160)		(121,120)
	Mortgage and mezzanine loans receivable		-		(82,512)		(104,727)
	Other, net		17,080		(6,223)		48,915
Estimable taxable income		$	776,728	$	545,237	$	467,851