Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Net Income (Loss) Available to Common Stockholders, Diluted	$ 122,547	$ 97,411
Operating activities:
Net income	134,451	109,315
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Gain (Loss) on Extinguishment of Debt	(977)	0
Asset Impairment Charges	10,195	0
Gain on sale of real estate	(27,465)	(2,270)
Gain on insurance recovery	(606)	(2,012)
Deferred income tax expense (benefit)	684	(620)
Costs associated with loan refinancing or payoff	14	891
Equity in income from joint ventures	(51)	(298)
Distributions from joint ventures	442	511
Depreciation and amortization	61,225	51,621
Amortization of deferred financing costs	2,981	2,335
Amortization of above and below market leases, net and tenant improvements	14	96
Share-based compensation expense to management and trustees	6,961	5,504
Increase in restricted cash	(1,714)	(1,665)
Decrease in mortgage notes accrued interest receivable	1,915	728
Decrease (increase) in accounts receivable, net	3,506	(4,327)
Increase in direct financing lease receivable	(804)	(1,736)
Increase in other assets	(2,195)	(4,745)
Increase in accounts payable and accrued liabilities	(12,280)	(931)
Increase in unearned rents and interest	3,974	135
Net cash provided by operating activities	180,270	152,532
Investing activities:
Acquisition of and investments in rental properties and other assets	197,097	138,788
Proceeds from sale of real estate	130,726	13,129
Investment in mortgage notes receivable	(101,721)	(65,508)
Proceeds from mortgage note receivable paydown	15,610	63,685
Investment in promissory notes receivable	1,387	0
Proceeds from promissory note receivable paydown	1,599	0
Proceeds from sale of infrastructure related to issuance of revenue bonds	0	43,462
Proceeds from insurance recovery	0	2,211
Proceeds from Sale of Lease Receivables	0	825
Additions to properties under development	(196,354)	(187,216)
Net cash used by investing activities	(348,624)	(268,200)
Financing activities:
Proceeds from long-term debt facilities	915,000	318,000
Principal payments on long-term debt	(601,962)	(203,116)
Deferred financing fees paid	(7,042)	(169)
Costs associated with loan refinancing or payoff (cash portion)	(6)	(472)
Net proceeds from issuance of common shares	68,352	142,279
Impact of stock option exercises, net	0	(717)
Purchase of common shares for treasury	(6,729)	(4,208)
Dividends paid to shareholders	(147,845)	(131,701)
Net cash provided by financing activities	219,768	119,896
Effect of exchange rate changes on cash	123	(49)
Net increase in cash and cash equivalents	51,537	4,179
Cash and cash equivalents at beginning of the year	19,335	4,283
Cash and cash equivalents at end of the year	70,872	8,462
Supplemental schedule of non-cash activity:
Transfer of property under development to rental property	206,115	224,057
Issuance of nonvested shares and restricted share units at fair value, including nonvested shares issued for payment of bonuses	23,983	19,626
Stock Issued During Period, Value, Acquisitions	657,473
Noncash or Part Noncash Acquisition, Net Nonmonetary Assets Acquired (Liabilities Assumed)	12,083	0
Supplemental disclosure of cash flow information:
Cash paid during the year for interest	65,623	48,608
Cash paid during the period for income taxes	654	1,116
Interest cost capitalized	5,340	5,051
Decrease (increase) in accrued capital expenditures	9,347	(5,598)
Additional Paid-in Capital [Member]
Supplemental schedule of non-cash activity:
Stock Issued During Period, Value, Acquisitions	$ 657,384	$ 0