Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
CASH FLOWS FROM OPERATING ACTIVITIES:
Consolidated Net Income	$ 1,551,590	$ 1,719,632	$ 1,245,900
Adjustments to reconcile consolidated net income to net cash provided by operating activities -
Depreciation and amortization	1,332,950	1,301,304	1,112,438
Gain upon acquisition of controlling interests, sale or disposal of assets and interests in unconsolidated entities, and impairment charge on investment in unconsolidated entities, net	(107,515)	(510,030)	(216,629)
Marketable and non-marketable securities charges and realized gains, net		(6,426)
Straight-line rent	(48,264)	(37,998)	(30,308)
Equity in income of unconsolidated entities	(205,259)	(131,907)	(81,238)
Distributions of income from unconsolidated entities	179,054	151,398	112,977
Changes in assets and liabilities -
Tenant receivables and accrued revenue, net	(13,938)	(4,815)	(19,370)
Deferred costs and other assets	(30,013)	(133,765)	(58,924)
Accounts payable, accrued expenses, intangibles, deferred revenues and other liabilities	42,391	165,679	(58,959)
Net cash provided by operating activities	2,700,996	2,513,072	2,005,887
CASH FLOWS FROM INVESTING ACTIVITIES:
Acquisitions	(866,541)	(3,735,718)	(1,259,623)
Funding of loans to related parties	(99,079)	(25,364)
Repayments from loans to related parties		92,600
Capital expenditures, net	(841,209)	(802,427)	(445,495)
Cash from acquisitions and cash impact from the consolidation and deconsolidation of properties		91,163	19,302
Net proceeds from sale of assets	274,058	383,804	136,013
Investments in unconsolidated entities	(143,149)	(201,330)	(20,807)
Purchase of marketable and non-marketable securities	(44,117)	(184,804)	(42,015)
Proceeds from sale of marketable and non-marketable securities	47,495	415,848	6,866
Repayments of loans held for investment		163,908	235,124
Distributions of capital from unconsolidated entities	724,454	221,649	376,593
Net cash used in investing activities	(948,088)	(3,580,671)	(994,042)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from sales of common stock and other, net of transaction costs	99	1,213,840	5,313
Redemption of limited partner units		(248,000)
Purchase of noncontrolling interest in consolidated properties		(229,595)
Distributions to noncontrolling interest holders in properties	(9,335)	(13,623)	(28,793)
Contributions from noncontrolling interest holders in properties	6,053	4,204	1,217
Preferred distributions of the Operating Partnership	(1,915)	(1,915)	(1,915)
Preferred dividends and distributions to stockholders	(1,446,042)	(1,244,553)	(1,030,744)
Distributions to limited partners	(242,596)	(238,772)	(211,497)
Proceeds from issuance of debt, net of transaction costs	2,919,364	6,772,443	1,655,203
Repayments of debt	(2,446,191)	(4,560,562)	(1,398,697)
Net cash (used in) provided by financing activities	(1,220,563)	1,453,467	(1,009,913)
INCREASE IN CASH AND CASH EQUIVALENTS	532,345	385,868	1,932
CASH AND CASH EQUIVALENTS, beginning of period	1,184,518	798,650	796,718
CASH AND CASH EQUIVALENTS, end of period	$ 1,716,863	$ 1,184,518	$ 798,650