Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Cash flow from operating activities:
Net income	$ 78,215	$ 142,154
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	92,074	84,856
Impairment charges	1,617	5,840
Equity award expense	9,631	7,877
Gain on sale of operating properties	(1,686)	(30,883)
Gain on change in control of interests	(10,188)
Equity in income of joint ventures, net	(14,733)	(69,933)
Equity in income from other real estate investments, net	(3,687)	(10,799)
Distributions from joint ventures and other real estate investments	13,258	26,730
Change in accounts and notes receivable	5,769	1,247
Change in accounts payable and accrued expenses	7,885	8,869
Change in other operating assets and liabilities	(21,103)	(29,002)
Net cash flow provided by operating activities	157,052	136,956
Cash flow from investing activities:
Acquisition of operating real estate and other related net assets	(38,390)	(11,436)
Improvements to operating real estate	(30,053)	(32,866)
Acquisition of real estate under development	(10,010)	(12,895)
Improvements to real estate under development	(44,434)	(5,333)
Proceeds from sale of marketable securities	457	1,850
Investments in and advances to real estate joint ventures	(16,874)	(17,505)
Reimbursements of investments in and advances to real estate joint ventures	13,523	28,327
Distributions from liquidation of real estate joint ventures		50,902
Return of investment from liquidation of real estate joint ventures		40,000
Investment in other real estate investments	(114)	(190)
Reimbursements of investments in and advances to other real estate investments	3,779	2,921
Collection of mortgage loans receivable	243	231
Proceeds from sale of operating properties	56,498	79,245
Proceeds from sale of development properties		4,551
Net cash flow (used for)/provided by investing activities	(65,375)	127,802
Cash flow from financing activities:
Principal payments on debt, excluding normal amortization of rental property debt	(59,100)	(101,205)
Principal payments on rental property debt	(4,544)	(5,971)
(Repayments)/proceeds from unsecured revolving credit facility, net	(15,042)	180,000
Proceeds from issuance of unsecured notes	400,000
Repayments under unsecured term loan/notes	(250,000)	(300,000)
Financing origination costs	(9,905)	(91)
Payment of early extinguishment of debt charges	(588)
Change in tenants' security deposits	316	594
Conversion/distribution of noncontrolling interests	(2,092)
Dividends paid	(126,315)	(117,030)
Proceeds from issuance of stock, net	561	111,411
Net cash flow used for financing activities	(66,709)	(232,292)
Change in cash and cash equivalents	24,968	32,466
Cash and cash equivalents, beginning of period	142,486	189,534
Cash and cash equivalents, end of period	167,454	222,000
Interest paid during the period (net of capitalized interest of $2,883 and $1,699, respectively)	24,286	39,508
Income taxes paid during the period	$ 2,801	$ 23,960