Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Cash Flows from Operating Activities:
Net income	$ 740,000	$ 708,031	$ 128,450
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization (including amortization of deferred financing costs)	580,990	556,312	559,053
Equity in income of partially owned entities including ToysRUs	(120,310)	(94,062)	(72,390)
Distributions of income from partially owned entities	93,635	61,037	30,473
Net (gain) loss on extinguishment of debt	(83,907)	(97,728)	25,915
Mezzanine loans loss (reversal) accrual and net gain on disposition	(82,744)	(53,100)	190,738
Amortization of below-market leases, net	(63,044)	(66,202)	(72,481)
Impairment losses, write-off of tenant buy-outs and litigation loss accrual	58,173	137,367	91,184
Net gain on sale of real estate	(51,623)	(2,506)	(45,284)
Straight-lining of rental income	(45,788)	(76,926)	(98,355)
Other non-cash adjustments	27,325	36,352	15,196
Recognition of disputed account receivable from Stop & Shop	(23,521)	0	0
Net realized and unrealized gains on Real Estate Fund assets	(17,386)	0	0
Net gain on disposition of wholly owned and partially owned assets	(15,134)	(81,432)	(5,641)
Income from the mark-to-market of J.C. Penney derivative position	(12,984)	(130,153)	0
Interest received on repayment on mezzanine loan	0	40,467	0
Write Off Of Unamortized Costs From Voluntary Surrender Of Equity Awards	0	0	32,588
Changes in operating assets and liabilities:
Real Estate Fund Investments	(184,841)	(144,423)	0
Accounts receivable, net	8,869	2,019	15,383
Prepaid assets	(7,779)	6,321	(90,519)
Other assets	(87,488)	(66,736)	(61,878)
Accounts payable and accrued expenses	(28,699)	2,645	(3,606)
Other liabilities	18,755	33,803	(5,247)
Net cash provided by operating activities	702,499	771,086	633,579
Cash Flows from Investing Activities:
Investments in partially owned entities	(571,922)	(165,170)	(38,266)
Distributions of capital from partially owned entities	318,966	51,677	16,790
Proceeds from sales and repayments of mezzanine loans receivable and other	187,294	70,762	47,397
Additions to real estate	(165,680)	(144,794)	(216,669)
Proceeds from sales of real estate and related investments	140,186	127,736	367,698
Restricted cash	126,380	138,586	111,788
Investments in mezzanine loans receivable and other	(98,979)	(85,336)	0
Development costs and construction in progress	(93,066)	(156,775)	(465,205)
Acquisitions of real estate and other	(90,858)	(173,413)	0
Proceeds from sales of, and return of investment in, marketable securities	70,418	280,462	64,355
Return of J.C. Penney derivative collateral	56,350	0	0
Funding of collateral for J.C. Penney derivative	(43,850)	(12,500)	0
Proceeds from the repayment of loan to officer	13,123	0	0
Loans to Officer	(13,123)	0	0
Purchases of marketable securities including J.C. Penney common shares and other	0	(491,596)	(90,089)
Proceeds from maturing short-term investments	0	40,000	15,000
Purchases of short-term investments	0	0	(55,000)
Net cash provided by (used in) investing activities	(164,761)	(520,361)	(242,201)
Cash Flows from Financing Activities:
Repayments of borrowings	(3,740,327)	(1,564,143)	(2,075,236)
Proceeds from borrowings	3,412,897	2,481,883	2,648,175
Distributions to Vornado	(508,745)	(474,299)	(262,397)
Proceeds from the issuance of Series J preferred units	238,842	0	0
Contributions from noncontrolling interests in consolidated subsidiaries	204,185	103,831	2,180
Distributions to noncontrolling interests in consolidated subsidiaries	(116,510)	(53,842)	(42,451)
Distributions to preferred unitholders	(61,464)	(55,669)	(57,076)
Debt issuance and other costs	(47,395)	(14,980)	(30,186)
Redemption of outstanding preferred units	(28,000)	(78,954)	(24,330)
Proceeds received from exercise of Vornado stock options	25,507	26,993	1,750
Repurchase of Class A units related to stock compensation agreements and related tax withholdings	(964)	(25,660)	(32,203)
Acquisition of convertible senior debentures and senior unsecured notes	0	(440,575)	(2,221,204)
Proceeds from issuance of Class A units to Vornado	0	0	710,226
Net cash used in provided by financing activities	(621,974)	(95,415)	(1,382,752)
Net (increase) decrease in cash and cash equivalents	(84,236)	155,310	(991,374)
Cash and cash equivalents at beginning of period	690,789	535,479	1,526,853
Cash and cash equivalents at end of period	606,553	690,789	535,479
Supplemental Disclosure Of Cash Flow Information [Abstract]
Cash payments for interest (net of amounts capitalized of $1,197, $864 and $17,256)	531,174	549,327	631,573
Cash payments for income taxes	26,187	23,960	21,775
Non-Cash Investing and Financing Activities:
Adjustment to carry redeemable Class A units at redemption value	98,092	(191,826)	(167,049)
Contribution of mezzanine loan receivable to joint venture	73,750	0	0
Write-off of fully depreciated assets	(72,279)	(63,007)	(86,291)
Class A units issued upon redemption of redeemable Class A units at redemption value	64,830	126,764	90,955
Change in unrealized net gain on securities available-for-sale	46,177	46,447	6,147
Like-kind exchange of real estate	(23,626)	0	0
Financing assumed in acquisitions	0	102,616	0
Distributions paid to Vornado in Class A units	0	0	285,596
Distributions paid to redeemable security holders paid in Class A units	0	0	23,876
Increase in assets and liabilities resulting from the consolidation of investments
Real Estate, net	0	102,804	0
Notes and mortgages payable	0	57,563	0
Decrease in assets and liabilities resulting from the deconsolidation of discontinued operations and/or investments that were previously consolidated:
Real Estate, Net	(145,333)	(401,857)	0
Notes and Mortgages Payable	(232,502)	(316,490)	0
Toys R Us [Member]
Adjustments to reconcile net income to net cash provided by operating activities:
Equity in income of partially owned entities including ToysRUs	(48,540)	(71,624)	(92,300)
All Equity Method Investees Excluding Toys [Member]
Adjustments to reconcile net income to net cash provided by operating activities:
Equity in income of partially owned entities including ToysRUs	$ (71,770)	$ (22,438)	$ 19,910