Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Cash flow from operating activities:
Net income	$ 116,678	$ 143,982
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	71,561	81,382
Impairment charges	4,175	7,646
Equity award expense	5,477	5,182
Gain on sale of properties/change in control of interests	(23,595)	(56,971)
Distributions from joint ventures and other real estate investments	28,524	34,661
Change in accounts and notes receivable	878	5,224
Change in accounts payable and accrued expenses	2,837	10,371
Change in other operating assets and liabilities	(26,299)	(12,309)
Net cash flow provided by operating activities	155,258	192,279
Cash flow from investing activities:
Acquisition of operating real estate and other related net assets		(3,337)
Improvements to operating real estate	(51,345)	(40,384)
Acquisition of real estate under development		(4,592)
Improvements to real estate under development	(26,286)	(54,934)
Investments in marketable securities	(157)
Proceeds from sale/repayments of marketable securities	39	129
Investments in and advances to real estate joint ventures	(5,638)	(5,897)
Reimbursements of investments in and advances to real estate joint ventures	1,435	2,431
Investments in and advances to other real estate investments	(6,771)	(302)
Reimbursements of investments in and advances to other real estate investments		1,344
Investment in other financing receivable	(48)
Collection of mortgage loans receivable	160	335
Proceeds from sale of operating properties	72,069	184,633
Proceeds from insurance casualty claims	1,000
Net cash flow (used for)/provided by investing activities	(15,542)	79,426
Cash flow from financing activities:
Principal payments on debt, excluding normal amortization of rental property debt	(3,224)	(161,547)
Principal payments on rental property debt	(3,137)	(3,485)
Proceeds from construction loan financing	3,300
Financing origination costs	(3)	(11)
Payment of early extinguishment of debt charges	(771)
Redemption/distribution of noncontrolling interests	(773)	(4,968)
Dividends paid	(132,521)	(130,241)
Proceeds from issuance of stock, net	681	33,144
Repurchase of common stock		(24,276)
Change in other financing liabilities	(3,176)	(521)
Net cash flow used for financing activities	(139,624)	(291,905)
Net change in cash and cash equivalents	92	(20,200)
Cash and cash equivalents, beginning of the period	143,581	238,513
Cash and cash equivalents, end of the period	143,673	218,313
Interest paid during the period including payment of early extinguishment of debt charges of $771 and $0, respectively (net of capitalized interest of $3,137 and $3,777, respectively)	27,026	29,084
Joint Ventures [Member]
Adjustments to reconcile net income to net cash provided by operating activities:
Equity in income	(18,754)	(16,913)
Other Real Estate Investments [Member]
Adjustments to reconcile net income to net cash provided by operating activities:
Equity in income	$ (6,224)	$ (9,976)