Consolidated Statements of Cash Flows - USD ($)		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Operating activities:
Net income		$ 829,750,000	$ 540,613,000	$ 1,082,070,000
Adjustments to reconcile net income to net cash provided from (used in) operating activities:
Depreciation and amortization		950,459,000	921,720,000	901,242,000
Other amortization expenses		17,000,000	16,521,000	8,822,000
Provision for loan losses		0	62,966,000	10,215,000
Impairment of assets		115,579,000	124,483,000	37,207,000
Stock-based compensation expense		27,646,000	19,102,000	28,869,000
Loss (gain) on derivatives and financial instruments, net		(4,016,000)	2,284,000	(2,448,000)
Loss (gain) on extinguishment of debt, net		16,097,000	37,241,000	17,214,000
Loss (income) from unconsolidated entities		641,000	83,125,000	10,357,000
Rental income in excess of cash received		(32,857,000)	(80,398,000)	(83,233,000)
Amortization related to above (below) market leases, net		2,608,000	357,000	322,000
Loss (gain) on real estate dispositions, net		(415,575,000)	(344,250,000)	(364,046,000)
Other (income) expense, net		0	2,000	(4,853,000)
Distributions by unconsolidated entities		21,000	116,000	1,065,000
Increase (decrease) in accrued expenses and other liabilities		70,762,000	26,809,000	14,298,000
Decrease (increase) in receivables and other assets		5,829,000	23,486,000	(18,037,000)
Net cash provided from (used in) operating activities		1,583,944,000	1,434,177,000	1,639,064,000
Investing activities:
Cash disbursed for acquisitions, net of cash acquired		(3,560,360,000)	(805,264,000)	(2,145,374,000)
Cash disbursed for capital improvements to existing properties		(266,183,000)	(250,276,000)	(219,146,000)
Cash disbursed for construction in progress		(160,706,000)	(232,715,000)	(403,131,000)
Capitalized interest		(7,905,000)	(13,489,000)	(16,943,000)
Investment in real estate loans receivable		(83,048,000)	(83,738,000)	(129,884,000)
Principal collected on real estate loans receivable		180,830,000	96,023,000	249,552,000
Other investments, net of payments		(50,430,000)	57,385,000	4,760,000
Contributions to unconsolidated entities		(136,854,000)	(114,365,000)	(101,415,000)
Distributions by unconsolidated entities		90,916,000	70,287,000	119,723,000
Proceeds from (payments on) derivatives		65,399,000	52,719,000	108,347,000
Proceeds from sales of real property		1,541,870,000	1,378,014,000	2,350,068,000
Net cash provided from (used in) investing activities		(2,386,471,000)	154,581,000	(183,443,000)
Financing activities:
Net increase (decrease) under unsecured credit facilities		428,000,000	74,000,000	(190,000,000)
Proceeds from issuance of senior unsecured notes		2,824,176,000	7,500,000	693,560,000
Payments to extinguish senior unsecured notes		(1,450,000,000)	(5,000,000)	(865,863,000)
Net proceeds from the issuance of secured debt		45,447,000	241,772,000	460,015,000
Payments on secured debt		(362,841,000)	(1,144,346,000)	(563,759,000)
Net proceeds from the issuance of common stock		789,575,000	621,987,000	534,194,000
Redemption of preferred stock		0	(287,500,000)	0
Payments for deferred financing costs and prepayment penalties		(29,691,000)	(54,333,000)	(22,196,000)
Contributions by noncontrolling interests	[1]	39,207,000	56,560,000	148,666,000
Distributions to noncontrolling interests	[1]	(109,871,000)	(87,711,000)	(134,578,000)
Cash distributions to stockholders		(1,348,863,000)	(1,325,617,000)	(1,298,925,000)
Other financing activities		(6,771,000)	(10,839,000)	(11,931,000)
Net cash provided from (used in) financing activities		818,368,000	(1,913,527,000)	(1,250,817,000)
Effect of foreign currency translation on cash and cash equivalents and restricted cash		(9,015,000)	26,852,000	(20,274,000)
Increase (decrease) in cash, cash equivalents and restricted cash		6,826,000	(297,917,000)	184,530,000
Cash, cash equivalents and restricted cash at beginning of period		309,303,000	607,220,000	422,690,000
Cash, cash equivalents and restricted cash at end of period		316,129,000	309,303,000	607,220,000
Supplemental cash flow information:
Interest paid		501,404,000	488,265,000	541,545,000
Income taxes paid		$ 2,250,000	$ 10,410,000	$ 8,011,000

[1] Includes amounts attributable to redeemable noncontrolling interests.