Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Cash flow from operating activities:
Net income	$ 218,065	$ 309,791
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	140,566	161,142
Impairment charges	21,626	30,519
Equity award expense	10,284	10,423
Gain on sale of properties/change in control of interests	(38,357)	(152,211)
Distributions from joint ventures and other real estate investments	60,858	67,005
Change in accounts and notes receivable	2,159	9,306
Change in accounts payable and accrued expenses	(8,382)	(5,139)
Change in other operating assets and liabilities	(32,510)	(23,304)
Net cash flow provided by operating activities	313,529	351,986
Cash flow from investing activities:
Acquisition of operating real estate and other related net assets	0	(3,337)
Improvements to operating real estate	(139,865)	(127,380)
Acquisition of real estate under development	0	(4,592)
Improvements to real estate under development	(57,496)	(121,393)
Investments in marketable securities	(157)	(63)
Proceeds from sale/repayments of marketable securities	151	129
Investments in and advances to real estate joint ventures	(16,214)	(15,240)
Reimbursements of investments in and advances to real estate joint ventures	2,702	5,228
Investments in and advances to other real estate investments	(9,685)	(353)
Reimbursements of investments in and advances to other real estate investments	5,960	10,444
Investment in other financing receivable	(48)	0
Collection of mortgage loans receivable	5,351	5,427
Proceeds from sale of operating properties	106,782	472,781
Proceeds from insurance casualty claims	2,000	6,500
Net cash flow (used for)/provided by investing activities	(100,519)	228,151
Cash flow from financing activities:
Principal payments on debt, excluding normal amortization of rental property debt	(6,198)	(175,209)
Principal payments on rental property debt	(6,179)	(6,852)
Proceeds from construction loan financing	7,149	0
Proceeds/(repayments) under the unsecured revolving credit facility, net	35,000	(7,746)
Repayments under unsecured notes	0	(6,365)
Financing origination costs	(7)	(11)
Payment of early extinguishment of debt charges	(1,531)	(546)
Redemption/distribution of noncontrolling interests	(4,060)	(5,454)
Dividends paid	(265,226)	(264,711)
Proceeds from issuance of stock, net	1,811	33,144
Repurchase of common stock	0	(75,126)
Change in other financing liabilities	(3,359)	(4,197)
Net cash flow used for financing activities	(242,600)	(513,073)
Net change in cash and cash equivalents	(29,590)	67,064
Cash and cash equivalents, beginning of the period	143,581	238,513
Cash and cash equivalents, end of the period	113,991	305,577
Interest paid during the period including payment of early extinguishment of debt charges of $1,531 and $546, respectively (net of capitalized interest of $6,680 and $8,199, respectively)	86,621	96,974
Joint Ventures [Member]
Adjustments to reconcile net income to net cash provided by operating activities:
Equity in income	(41,287)	(35,953)
Other Real Estate Investments [Member]
Adjustments to reconcile net income to net cash provided by operating activities:
Equity in income	$ (19,493)	$ (19,593)