Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Cash Flows from Operating Activities:
Net income	$ 433,040	$ 603,499
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization (including amortization of deferred financing costs)	423,959	419,249
Proceeds from Real Estate Fund investments	215,676	56,664
Net realized and unrealized gains on Real Estate Fund investments	(131,558)	(59,476)
Equity in net loss of partially owned entities, including Toys "R" Us	77,426	45,620
Net gains on sale of real estate	(57,796)	(286,990)
Straight-lining of rental income	(56,983)	(48,561)
Distributions of income from partially owned entities	42,164	34,350
Amortization of below-market leases, net	(32,663)	(40,341)
Other non-cash adjustments	28,691	60,957
Impairment losses	20,842	4,727
Net (gain) loss on disposition of wholly owned and partially owned assets	(13,205)	20,581
Defeasance cost in connection with the refinancing of mortgage notes payable	5,589	0
Non-cash impairment loss on J.C. Penney common shares	0	39,487
Loss from the mark-to-market of J.C. Penney derivative position	0	33,487
Changes in operating assets and liabilities:
Real Estate Fund investments	(3,392)	(32,392)
Accounts receivable, net	(2,775)	63,280
Prepaid assets	(85,372)	(60,388)
Other assets	(68,833)	(25,854)
Accounts payable and accrued expenses	36,949	(38,904)
Other liabilities	(3,190)	597
Net cash provided by operating activities	828,569	789,592
Cash Flows from Investing Activities:
Development costs and construction in progress	(368,571)	(149,010)
Proceeds from sales of real estate and related investments	335,489	734,427
Additions to real estate	(171,660)	(170,424)
Restricted cash	101,592	21,883
Acquisitions of real estate and other	(95,546)	(75,079)
Proceeds from repayments of mortgage and mezzanine loans receivable and other	96,504	49,452
Investments in partially owned entities	(91,697)	(212,624)
Investment in mortgage and mezzanine loans receivable and other	(11,380)	(390)
Distributions of capital from partially owned entities	8,130	287,944
Proceeds from sales of marketable securities	0	378,676
Proceeds from the sale of LNR	0	240,474
Funding of J.C. Penney derivative collateral and settlement of derivative	0	(186,079)
Return of J.C. Penney derivative collateral	0	101,150
Net cash (used in) provided by investing activities	(197,139)	1,020,400
Cash Flows from Financing Activities:
Proceeds from borrowings	1,713,285	1,600,357
Dividends paid on common shares	(410,724)	(409,332)
Repayments of borrowings	(343,354)	(2,851,420)
Distributions to noncontrolling interests	(208,773)	(200,667)
Purchase of marketable securities in connection with the defeasance of mortgage notes payable	(198,884)	0
Dividends paid on preferred shares	(61,102)	(62,820)
Debt issuance costs	(40,424)	(9,982)
Proceeds received from exercise of employee share options	13,738	5,057
Contributions from noncontrolling interests	5,297	40,015
Repurchase of shares related to stock compensation agreements and/or related tax withholdings	(637)	(332)
Purchases of outstanding preferred units and shares	0	(299,400)
Proceeds from the issuance of preferred shares	0	290,536
Net cash provided by (used in) financing activities	468,422	(1,897,988)
Net increase (decrease) in cash and cash equivalents	1,099,852	(87,996)
Cash and cash equivalents at beginning of period	583,290	960,319
Cash and cash equivalents at end of period	1,683,142	872,323
Supplemental Disclosure Of Cash Flow Information:
Cash payments for interest, excluding capitalized interest of $46,517 and $28,024	317,162	350,899
Cash payments for income taxes	9,407	7,529
Non-cash Investing and Financing Activities:
Marketable securities transferred in connection with the defeasance of mortgage notes payable	198,884	0
Defeasance of mortgage notes payable	(193,406)	0
Adjustments to carry redeemable Class A units at redemption value	(144,231)	(43,709)
Write-off of fully depreciated assets	(103,184)	(54,377)
Elimination of a mortgage and mezzanine loan asset and liability	59,375	0
Transfer of interest in Real Estate Fund to an unconsolidated joint venture	(58,564)	0
Transfer of noncontrolling interest in Real Estate Fund	(33,028)	0
Beverly Connection seller financing	13,620	0
Decrease in assets and liabilities resulting from deconsolidation of Independance Plaza:
"Real estate, Net"	0	(852,166)
Notes and mortgages payable	0	(322,903)
Acquisitions [Member]
Non-cash Investing and Financing Activities:
Like-kind exchange of real estate	50,159	7,663
Dispositions [Member]
Non-cash Investing and Financing Activities:
Like-kind exchange of real estate	$ (50,159)	$ (163,468)