Consolidated Statements of Cash Flows - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Operating activities
Net income (loss)		$ 1,082,070	$ 888,549	$ 512,300
Adjustments to reconcile net income to net cash provided from (used in) operating activities:
Depreciation and amortization expenses		901,242	826,240	844,130
Other amortization expenses		8,822	4,991	6,971
Provision for loan losses		10,215	0	0
Impairment of assets		37,207	2,220	0
Stock-based compensation expense		28,869	30,844	32,075
Loss on derivatives		(2,448)	(58,427)	(1,495)
Loss (gain) on extinguishment of debt, net		17,214	34,677	9,558
Income from unconsolidated entities		10,357	21,504	27,426
Rental income less than (in excess of) cash received		(83,233)	(115,756)	(74,552)
Amortization related to above (below) market leases, net		322	4,018	739
Gain Loss On Sale Of Properties		(364,046)	(280,387)	(153,522)
Other (income) expense		(4,853)	31,979	0
Distributions by unconsolidated entities operating		1,065	637	9,060
Increase (decrease) in accrued expenses and other liabilities		3,929	(18,099)	(48,381)
Decrease (increase) in receivables and other assets		(18,037)	478	(25,639)
Net cash provided from (used in) operating activities		1,628,695	1,373,468	1,138,670
Investing activities
Cash disbursed for acquisitions		(2,145,590)	(3,364,891)	(2,210,600)
Cash disbursed for capital improvements to existing properties		(219,146)	(187,752)	(132,780)
Cash disbursed for construction in progress		(403,131)	(244,561)	(197,881)
Capitalized interest		(16,943)	(8,670)	(7,150)
Investment in real estate loans receivable		(129,884)	(598,722)	(202,207)
Other investments, net of payments		4,760	(141,994)	(100,033)
Principal collected on real estate loans receivable		249,552	131,830	105,496
Contributions to unconsolidated entities		(101,415)	(160,323)	(353,496)
Distributions by unconsolidated entities investing		119,723	130,880	57,183
Proceeds from (payments on) derivatives investing		108,347	106,360	10,269
Decrease (increase) in restricted cash		(125,844)	29,719	(6,072)
Proceeds from sales of real property		2,350,068	823,964	911,065
Net cash provided from (used in) investing activities		(309,503)	(3,484,160)	(2,126,206)
Financing activities
Net increase (decrease) under unsecured lines of credit arrangements		(190,000)	835,000	(130,000)
Proceeds from issuance of senior unsecured notes		693,560	1,451,434	773,992
Payments to extinguish senior unsecured notes		(865,863)	(558,830)	(365,188)
Secured debt issued		460,015	228,685	109,503
Payments on secured debt		(563,759)	(573,390)	(341,839)
Net proceeds from the issuance of common stock		534,194	1,755,722	2,343,868
Decrease (increase) in deferred loan expenses		(22,196)	(11,513)	(16,782)
Contributions by noncontrolling interests	[1]	148,666	173,018	9,962
Distributions to noncontrolling interests	[1]	(134,578)	(50,877)	(43,691)
Acquisitions of non controlling interests		0	(5,663)	(1,175)
Cash distributions to stockholders		(1,298,925)	(1,210,133)	(1,035,069)
Other financing activities		(1,562)	(27,004)	(409)
Net cash provided from (used in) financing activities		(1,240,448)	2,006,449	1,303,172
Effect of foreign currency translation on cash and cash equivalents		(20,274)	(8,575)	(690)
Increase (decrease) in cash and cash equivalents		58,470	(112,818)	314,946
Cash and cash equivalents at beginning of period		360,908	473,726	158,780
Cash and cash equivalents at end of period		419,378	360,908	473,726
Supplemental cash flow information:
Interest paid		541,545	492,771	504,165
Income taxes paid		$ 8,011	$ 12,214	$ 18,548

[1] Includes amounts attributable to redeemable noncontrolling interests.