Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Net Income (Loss) Available to Common Stockholders, Diluted	$ 72,388	$ 61,778
Operating activities:
Net income	84,292	73,682
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Gain on early extinguishment of debt	0	(4,539)
Income from discontinued operations	(3,387)	(959)
Gain on sale of land	(330)	0
gain on sale of investment in a direct financing lease	(220)	0
Costs associated with loan refinancing or payoff	0	5,943
Equity in income from joint ventures	578	817
Distributions from joint ventures	0	414
Depreciation and amortization	31,329	25,998
Amortization of deferred financing costs	2,076	1,987
Amortization of above and below Market Leases	96	0
Share-based compensation expense to management and trustees	4,671	3,166
Decrease (increase) in restricted cash	(2,671)	12,064
Decrease (increase) in mortgage notes accrued interest receivable	(236)	1,628
Increase in accounts receivable, net	(533)	(2,861)
Increase in direct financing lease receivable	(1,682)	(2,452)
Increase in other assets	(3,392)	(1,819)
Decrease in accounts payable and accrued liabilities	(2)	(249)
Increase (decrease) in unearned rents and interest	4,801	(905)
Net Cash Provided by (Used in) Operating Activities, Continuing Operations	114,234	110,281
Net operating cash provided by discontinued operations	120	2,445
Net cash provided by operating activities	114,354	112,726
Investing activities:
Payments to Acquire Real Estate	44,340	18,893
Proceeds from sale of real estate	3,293	796
Investment in unconsolidated joint ventures	0	(622)
Proceeds from settlement of derivative	(5,725)	0
Investment in mortgage notes receivable	(22,293)	(28,138)
Proceeds from mortgage note receivable paydown	176	0
Investment in promissory notes receivable	3,957	0
Investment in a direct financing lease, net	0	3,262
Proceeds from sale of investments in a direct financing lease, net	46,092	0
Additions to properties under development	(151,343)	(72,328)
Net cash used by investing activities of continuing operations	(166,647)	(122,447)
Net proceeds from sale of real estate from discontinued operations	0	24,146
Net cash used by investing activities	(166,647)	(98,301)
Financing activities:
Proceeds from long-term debt facilities	126,000	434,000
Principal payments on long-term debt	(42,976)	(321,380)
Deferred financing fees paid	(634)	(3,777)
Proceeds from (Payments for) Other Financing Activities	0	(5,755)
Net proceeds from issuance of common shares	79,669	5,139
Impact of stock option exercises, net	(24)	(662)
Purchase of common shares for treasury	(2,892)	(3,246)
Dividends paid to shareholders	(101,249)	(108,969)
Net cash provided (used) by financing activities	57,894	(4,650)
Effect of exchange rate changes on cash	30	(409)
Net increase in cash and cash equivalents	5,631	9,366
Cash and cash equivalents at beginning of the year	7,958	10,664
Cash and cash equivalents at end of the year	13,589	20,030
Supplemental schedule of non-cash activity:
Transfer of property under development to rental property	57,638	21,344
Acquisiton of real estate in exchange for assumption of debt at fair value	101,441	0
Issuance of nonvested shares and restricted share units at fair value, including nonvested shares issued for payment of bonuses	15,525	10,326
Supplemental disclosure of cash flow information:
Cash paid during the year for interest	42,060	39,446
Cash paid during the period for income taxes	$ 750	$ 440