Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Cash flow from operating activities:
Net income	$ 385,119	$ 180,968
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	199,914	191,420
Impairment charges	107,034	167,153
Gain on sale of operating properties	(130,052)	(29,859)
Equity in income of joint ventures, net	(150,073)	(179,791)
Gains on change in control of interests	(83,773)	(21,711)
Equity in income from other real estate investments, net	(16,404)	(29,910)
Distributions from joint ventures and other real estate investments	186,629	211,362
Change in accounts and notes receivable	3,168	11,414
Change in accounts payable and accrued expenses	35,289	69,053
Change in other operating assets and liabilities	(26,846)	(36,258)
Net cash flow provided by operating activities	510,005	533,841
Cash flow from investing activities:
Acquisition of operating real estate	(382,128)	(182,423)
Improvements to operating real estate	(93,733)	(78,490)
Improvements to real estate under development	(154)	(541)
Investment in marketable securities	(4,556)	(33,588)
Proceeds from sale/repayments of marketable securities	3,780	10,800
Investments and advances to real estate joint ventures	(59,602)	(289,494)
Reimbursements of investments and advances to real estate joint ventures	144,359	409,748
Investment in other real estate investments	(3,851)	(23,488)
Reimbursements of investments and advances to other real estate investments	12,981	19,557
Investment in mortgage loans receivable		(11,469)
Collection of mortgage loans receivable	7,707	13,900
Investment in other investments		(21,366)
Reimbursements of other investments		9,175
Proceeds from sale of operating properties	303,104	247,965
Net cash flow (used for)/provided by investing activities	(72,093)	70,286
Cash flow from financing activities:
Principal payments on debt, excluding normal amortization of rental property debt	(298,264)	(132,492)
Principal payments on rental property debt	(17,098)	(18,264)
Proceeds from mortgage loan financings	15,700	35,974
Proceeds/(repayments) under unsecured revolving credit facility, net	55,646	(99,076)
Proceeds from issuance of unsecured term loan/notes	500,000	621,562
Repayments under unsecured term loan/notes	(370,842)	(446,717)
Financing origination costs	(11,911)	(7,364)
Redemption of/distributions to noncontrolling interests, net	(1,059)	(27,184)
Dividends paid	(320,749)	(299,754)
Proceeds from issuance of stock	16,087	29,043
Net cash flow used for financing activities	(432,490)	(344,272)
Change in cash and cash equivalents	5,422	259,855
Cash and cash equivalents, beginning of period	148,768	141,875
Cash and cash equivalents, end of period	154,190	401,730
Interest paid during the period (net of capitalized interest of $1,288 and $888, respectively)	135,706	142,805
Income taxes paid during the period	$ 12,944	$ 1,240