Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Cash Flows from Operating Activities:
Net income	$ 280,264	$ 445,821
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization (including amortization of deferred financing costs)	145,304	136,860
Equity in net income of partially owned entities, including Toys R Us	(136,504)	(129,228)
Net gains on sale of real estate	(55,817)	(51,165)
Straight-lining of rental income	(21,808)	(13,942)
Distributions of income from partially owned entities	14,194	25,921
Amortization of below-market leases, net	(13,813)	(16,892)
Other non-cash adjustments	7,795	8,211
Unrealized gain on Real Estate Fund assets	(6,844)	0
Income from the mark-to-market of J.C. Penney derivative position	(1,045)	(17,163)
Net gain on extinguishment of debt	0	(83,907)
Mezzanine loans loss reversal and net gain on disposition	0	(82,744)
Net gain on disposition of wholly owned and partially owned assets	0	(6,677)
Changes in operating assets and liabilities:
Real Estate Fund investments	28,980	(85,536)
Accounts receivable, net	(19,386)	(10,475)
Prepaid assets	51,202	34,761
Other assets	(8,872)	2,947
Accounts payable and accrued expenses	40,609	30,906
Other liabilities	2,844	8,404
Net cash provided by operating activities	307,103	196,102
Cash Flows from Investing Activities:
Proceeds from sales of real estate and related investments	306,022	127,199
Investments in partially owned entities	(46,732)	(316,129)
Additions to real estate	(44,052)	(30,281)
Acquisitions of real estate and other	(21,054)	0
Development costs and construction in progress	(20,614)	(10,994)
Restricted cash	(19,355)	12,174
Proceeds from the repayment of loan to officer	13,123	0
Distributions of capital from partially owned entities	4,203	192,523
Proceeds from sales and repayments of mezzanine loans	554	73,608
Proceeds from sales of marketable securities	0	15,162
Investments in mezzanine loans receivable and other	0	(2,841)
Net cash provided by investing activities	172,095	60,421
Cash Flows from Financing Activities:
Repayments of borrowings	(884,679)	(1,197,312)
Proceeds from borrowings	625,000	937,518
Distributions to Vornado	(127,973)	(126,936)
Distributions to redeemable security holders and noncontrolling interests	(34,092)	(23,639)
Repurchase of Class A units related to stock compensation agreements and related tax withholdings	(30,034)	(570)
Distributions to preferred unitholders	(17,789)	(13,559)
Debt issuance and other costs	(9,822)	(12,161)
Proceeds received from exercise of Vornado stock options	7,997	15,470
Contributions from noncontrolling interests in consolidated subsidiaries	0	92,238
Net cash used in financing activities	(471,392)	(328,951)
Net increase (decrease) in cash and cash equivalents	7,806	(72,428)
Cash and cash equivalents at beginning of period	606,553	690,789
Cash and cash equivalents at end of period	614,359	618,361
Supplemental Disclosure of Cash Flow Information:
Cash payments for interest, net of capitalized interest of $16 and $0	117,282	108,458
Cash payments for income taxes	2,563	2,509
Non-Cash Investing and Financing Activities:
Adjustment to carry redeemable Class A units at redemption value	(96,061)	(42,227)
Class A units issued upon redemption of redeemable Class A units at redemption value	13,028	27,539
Change in unrealized net gain on securities available-for-sale	12,693	68,039
Contribution Of Mezzanine Loan Receivable To Joint Venture	0	73,750
Like-kind exchange of real estate	0	(45,625)
Decrease in assets and liabilities resulting from deconsolidation of discontinued operations:
Assets related to discontinued operations	0	(145,333)
Liabilities related to discontinued operations	0	(232,502)
Write-off of fully depreciated assets	(37,890)	(25,893)
Toys R Us [Member]
Adjustments to reconcile net income to net cash provided by operating activities:
Equity in net income of partially owned entities, including Toys R Us	(116,471)	(112,944)
All Equity Method Investees Excluding Toys [Member]
Adjustments to reconcile net income to net cash provided by operating activities:
Equity in net income of partially owned entities, including Toys R Us	$ (20,033)	$ (16,284)