Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash Flows from Operating Activities:
Net Income	$ 118,959	$ 322,575	$ 345,343
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	149,930	135,674	161,838
Amortization of debt deferred costs and intangibles, net	2,752	3,194	3,146
Non-cash lease expense	1,242	1,241	0
Impairment loss	24,153	74	10,120
Equity in earnings of real estate joint ventures and partnerships, net	(39,206)	(20,769)	(25,070)
Gain on sale of property	(65,402)	(189,914)	(207,865)
Distributions of income from real estate joint ventures and partnerships	29,803	20,083	19,605
Changes in accrued rent, accrued contract receivables and accounts receivable, net	1,154	10,001	(2,807)
Changes in unamortized lease costs and other assets, net	(8,024)	(14,298)	(8,632)
Changes in accounts payable, accrued expenses and other liabilities, net	5,744	(975)	(2,315)
Other, net	3,122	3,164	(7,403)
Net cash provided by operating activities	224,227	270,050	285,960
Cash Flows from Investing Activities:
Acquisition of real estate and land, net	(42,209)	(218,849)	(1,265)
Development and capital improvements	(137,059)	(183,188)	(155,528)
Proceeds from sale of property and real estate equity investments, net	119,442	445,319	607,486
Real estate joint ventures and partnerships - Investments	(8,671)	(74,602)	(38,096)
Real estate joint ventures and partnerships - Distribution of capital	22,228	2,482	6,936
Proceeds from investments		10,375	1,500
Other, net	(114)	2,437	11,921
Net cash (used in) provided by investing activities	(46,383)	(16,026)	432,954
Cash Flows from Financing Activities:
Proceeds from issuance of debt			638
Principal payments of debt	(22,977)	(55,556)	(257,028)
Changes in unsecured credit facilities	40,000	(5,000)	5,000
Proceeds from issuance of common shares of beneficial interest, net	212	1,098	6,760
Repurchase of common shares of beneficial interest, net	(32,107)		(18,564)
Common share dividends paid	(165,958)	(203,297)	(382,464)
Debt issuance and extinguishment costs paid	(6)	(3,271)	(1,271)
Distributions to noncontrolling interests	(4,076)	(6,782)	(19,155)
Contributions from noncontrolling interests	1,150	326	1,465
Other, net	(1,617)	(2,388)	508
Net cash used in financing activities	(185,379)	(274,870)	(664,111)
Net (decrease) increase in cash, cash equivalents and restricted cash equivalents	(7,535)	(20,846)	54,803
Cash, cash equivalents and restricted cash equivalents at January 1	55,291	76,137	21,334
Cash, cash equivalents and restricted cash equivalents at December 31	47,756	55,291	76,137
Supplemental disclosure of cash flow information:
Cash paid for interest (net of amount capitalized of $8,184, $13,586 and $7,938, respectively)	58,744	55,413	65,507
Cash paid for income taxes	793	1,526	1,545
Cash paid for amounts included in operating lease liabilities	$ 2,678	$ 2,785	$ 0