Consolidated Statements Of Cash Flows - USD ($) $ in Thousands		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018
Operating activities:
Net income		$ 131,943	$ 121,119
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Asset Impairment Charges		0	16,548
Gain on sale of real estate		(16,102)	(473)
Deferred income tax (benefit) expense		(2,284)	663
Costs associated with loan refinancing or payoff		0	31,958
Equity in (income) loss from joint ventures		959	(37)
Proceeds from Equity Method Investment, Distribution		112	567
Depreciation and amortization		82,098	75,266
Amortization of deferred financing costs		3,019	2,837
Amortization of above/below market leases and tenant allowances, net		(117)	(472)
Share-based compensation expense to management and trustees		6,563	7,608
Increase (Decrease) in Operating Lease Assets and Liabilities, Net		(290)	0
Mortgage notes accrued interest receivable		(1,544)	(374)
Accounts receivable		12,435	(5,625)
Increase in direct financing lease receivable		(117)	(401)
Other assets		(5,434)	(3,989)
Accounts payable and accrued liabilities		50	(6,758)
Increase (Decrease) in Deferred Revenue		383	11,237
Net cash provided by operating activities		209,756	249,748
Investing activities:
Acquisition of and investments in real estate and other assets		418,114	84,306
Proceeds from sale of real estate		95,958	6,195
Investment in unconsolidated joint ventures		325	0
Investment in mortgage notes receivable		(33,074)	(21,079)
Proceeds from Sale and Collection of Mortgage Notes Receivable		1,954	196,038
Investment in promissory notes receivable		9,068	7,739
Proceeds from promissory note receivable paydown		3,574	7,500
Additions to properties under development		(102,101)	(135,605)
Net cash used by investing activities		(461,196)	(38,996)
Financing activities:
Proceeds from long-term debt facilities		422,000	840,000
Principal payments on long-term debt		(218,150)	(881,684)
Deferred financing fees paid		(276)	(8,557)
Costs associated with loan refinancing or payoff (cash portion)		0	(28,650)
Net proceeds from issuance of common shares		231,407	530
Payment, Tax Withholding, Share-based Payment Arrangement		(732)	0
Purchase of common shares for treasury		(9,499)	(7,156)
Dividends paid to shareholders		(179,989)	(169,831)
Net cash provided (used) by financing activities		244,761	(255,348)
Effect of exchange rate changes on cash		109	(90)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect		(6,570)	(44,686)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents		11,937	14,300
Cash and Cash Equivalents, at Carrying Value		6,927	3,017
Restricted Cash and Cash Equivalents		5,010	11,283
Supplemental schedule of non-cash activity:
Transfer of property under development to rental property		282,275	110,742
Issuance of nonvested shares and restricted share units at fair value, including nonvested shares issued for payment of bonuses		17,590	18,252
Noncash or Part Noncash Acquisition, Value of Assets Acquired		0	155,185
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability			0
Operating Lease, Cost			0
Straight-Line Rent Receivable	[1]	95,449
Other Real Estate, Additions		14,000	0
Noncash or Part Noncash Acquisition, Debt Assumed		18,585	0
Supplemental disclosure of cash flow information:
Cash paid during the year for interest		70,954	75,386
Cash paid during the period for income taxes		1,066	1,105
Interest cost capitalized		4,667	4,538
Change in accrued capital expenditures		$ 8,854	$ (3,394)

[1] At June 30, 2019, includes $24.8 million in sub-lessor straight-line rent receivables. Sub-lessor straight-line receivables relate to the Company's operating ground leases. The Company's tenants, who are generally sub-tenants under these ground leases, are responsible for paying the rent under these leases. See Note 16 for information related to the Company's leases.