Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Cash flow from operating activities:
Net income	$ 521,432	$ 385,119
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	258,432	199,914
Impairment charges	27,989	107,034
Equity award expense	15,312	14,465
Gain on sale of operating properties	(88,497)	(130,052)
Gain on sale of marketable securities	(38,488)
Gains on change in control of interests	(146,143)	(83,773)
Equity in income of joint ventures, net	(130,808)	(150,073)
Equity in income from other real estate investments, net	(31,236)	(16,404)
Distributions from joint ventures and other real estate investments	149,141	186,629
Change in accounts and notes receivable	(372)	3,168
Change in accounts payable and accrued expenses	38,703	35,289
Change in other operating assets and liabilities	(58,181)	(41,311)
Net cash flow provided by operating activities	517,284	510,005
Cash flow from investing activities:
Acquisition of operating real estate and other related net assets	(619,622)	(382,128)
Improvements to operating real estate	(111,740)	(93,733)
Acquisition of real estate under development	(3,074)
Improvements to real estate under development	(8,922)	(154)
Investment in marketable securities	(257)	(4,556)
Proceeds from sale of marketable securities	71,562	3,780
Investments and advances to real estate joint ventures	(87,953)	(59,602)
Reimbursements of investments and advances to real estate joint ventures	98,741	144,359
Investment in other real estate investments	(545)	(3,851)
Reimbursements of investments and advances to other real estate investments	40,556	12,981
Collection of mortgage loans receivable	52,963	7,707
Investment in other investments	(190,278)
Proceeds from sale of operating properties	238,444	303,104
Net cash flow used for investing activities	(520,125)	(72,093)
Cash flow from financing activities:
Principal payments on debt, excluding normal amortization of rental property debt	(444,150)	(298,264)
Principal payments on rental property debt	(22,452)	(17,098)
Proceeds from mortgage loan financings		15,700
Proceeds under unsecured revolving credit facility, net	325,000	55,646
Proceeds from issuance of unsecured term loan/notes	1,000,000	500,000
Repayments under unsecured term loan/notes	(600,000)	(370,842)
Financing origination costs	(9,132)	(11,911)
Contributions from noncontrolling interests	106,154	1,133
Redemption/distribution of noncontrolling interests	(33,810)	(2,192)
Dividends paid	(340,745)	(320,749)
Proceeds from issuance of stock	15,567	16,087
Net cash flow provided by/(used for) financing activities	(3,568)	(432,490)
Change in cash and cash equivalents	(6,409)	5,422
Cash and cash equivalents, beginning of period	187,322	148,768
Cash and cash equivalents, end of period	180,913	154,190
Interest paid during the period (net of capitalized interest of $3,784 and $1,288, respectively)	150,625	135,706
Income taxes paid during the period	$ 5,985	$ 12,944