Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Operating activities:
Net (loss) income	$ (111,751)	$ 165,946
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Impairment of Real Estate	62,825	0
Impairment Losses Related to Real Estate Partnerships	3,247	0
Gain on sale of real estate	(242)	(30,405)
Deferred income tax expense	15,246	(3,268)
Write off of deferred debt issuance cost continuing and discontinued	820	38,407
Equity in loss (income) from joint ventures	(3,188)	524
Proceeds from Equity Method Investment, Distribution	0	112
Financing Receivable, Credit Loss, Expense (Reversal)	10,383	0
depreciation and amort cont and discops	128,319	127,232
Amortization of deferred financing costs	4,783	4,571
Amortization of above/below market leases and tenant allowances, net	(384)	(224)
Share-based Payment Arrangement, Noncash Expense	10,382	9,832
Increase (Decrease) in Operating Lease Assets and Liabilities, Net	574	1,033
Mortgage notes accrued interest receivable	(4,279)	(389)
Accounts receivable	(42,961)	12,935
Increase in direct financing lease receivable	0	(169)
Other assets	(3,065)	(3,189)
Accounts payable and accrued liabilities	(15,724)	5,689
Increase (Decrease) in Deferred Revenue	(1,883)	9,152
Net cash provided by operating activities	59,478	337,262
Investing activities:
Acquisition of and investments in real estate and other assets	37,128	443,561
Proceeds from Sale of Productive Assets	3,839	182,719
Investment in unconsolidated joint ventures	1,690	325
Investment in mortgage notes receivable	(6,438)	(98,071)
Proceeds from Sale and Collection of Mortgage Notes Receivable	414	207,125
Investment in promissory notes receivable	0	10,639
Proceeds from promissory note receivable paydown	69	3,637
Additions to properties under development	(29,963)	(125,635)
Net cash used by investing activities	(70,897)	(284,750)
Financing activities:
Proceeds from long-term debt facilities	750,000	962,000
Principal payments on long-term debt	0	(866,735)
Deferred financing fees paid	(2,944)	(9,343)
Proceeds from (Payments for) Other Financing Activities	(820)	(36,918)
Net proceeds from issuance of common shares	861	285,269
Payment, Tax Withholding, Share-based Payment Arrangement	0	(732)
Purchase of common shares for treasury	(6,792)	(9,691)
payments for repurchase of common stock, repurchase program	(105,994)	0
Dividends paid to shareholders	(166,426)	(273,187)
Net cash provided by financing activities	467,885	50,663
Effect of exchange rate changes on cash	(110)	86
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect	456,356	103,261
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	987,796	121,768
Cash and Cash Equivalents, at Carrying Value	985,372	115,839
Restricted Cash and Cash Equivalents	2,424	5,929
Supplemental schedule of non-cash activity:
Transfer of property under development to rental property	20,547	353,947
Issuance of nonvested shares and restricted share units at fair value, including nonvested shares issued for payment of bonuses	19,956	17,590
Financing Receivable, Allowance for Credit Loss	12,546	0
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	0	229,620
Operating Lease, Cost	0	253,486
Straight-Line Rent Receivable	51,925
Other Real Estate, Additions	0	14,000
Noncash or Part Noncash Acquisition, Debt Assumed	0	18,585
Supplemental disclosure of cash flow information:
Interest Paid, Excluding Capitalized Interest, Operating Activities	105,141	101,982
Cash paid during the period for income taxes	995	1,332
Interest cost capitalized	829	5,053
Change in accrued capital expenditures	(12,232)	(2,247)
Straight-Line Rent Receivable	51,925
Share-based Payment Arrangement, Noncash Expense	10,382	9,832
Restricted Stock or Unit Expense	0	521
Ground Lease Arrangement [Member]
Supplemental schedule of non-cash activity:
Straight-Line Rent Receivable	0	24,454
Straight-Line Rent Receivable	$ 0	$ 24,454