CONSOLIDATED STATEMENT OF CHANGES IN EQUITY (Unaudited) (USD $) In Thousands, unless otherwise specified	Total	PREFERRED SHARES	COMMON SHARES, $0.01 PAR VALUE	Additional Paid-in Capital [Member]	RETAINED EARNINGS	Accumulated Other Comprehensive (Loss)	OPERATING PARTNERSHIP	Partially Owned Properties [Member]
Beginning Balance, Noncontrolling Interest at Dec. 31, 2013	$ 337,995						$ 211,412	$ 126,583
Beginning Balance, Parent at Dec. 31, 2013	10,507,201	50,000	3,605	8,561,500	2,047,258	(155,162)
Common Share Issuance:
Conversion of OP Units held by Noncontrolling Interests into OP Units held by General Partner				480			(480)
Exercise of share options			5	15,780
Stock Issued During Period, Value, Employee Stock Purchase Plan				1,741
Conversion of restricted shares to Ltip Units				(278)			278
Share-based employee compensation expense:
Adjustments to Additional Paid in Capital, Share-based Compensation, Restricted Stock Unit or Restricted Stock Award, Requisite Service Period Recognition			1	4,869
Share options				3,122
ESPP discount				477
Payments for Repurchase of Common Stock	(1,777)			(1,777)
Supplemental Executive Retirement Plan (SERP)				848
Acquisition Noncontrolling Interests Partially Owned Properties				(553)				(1,000)
Change in market value	(44,530)			(44,530)
Adjustment for Noncontrolling Interests ownership in Operating Partnership				(633)			633
Net income attributable to controlling interests	79,135				79,135
Common Share distributions					(180,559)
Dividends, Preferred Stock, Cash					(1,036)
Other comprehensive (loss) income – derivative instruments:
Unrealized holding (losses) gains arising during the period	(11,952)					(11,952)
Losses reclassified into earnings from other comprehensive income	(4,129)					4,129
Currency translation adjustments arising during the period	91					91
Issuance of LTIP Units to Noncontrolling Interests							3
Equity Compensation associated with Noncontrolling Interests							5,190
Net (Income) Attributable to Noncontrolling Interest	3,093						3,093	504
Contributions by Noncontrolling Interests	5,684							5,684
Distributions to Noncontrolling Interests							(7,188)	(4,113)
Change in carrying value	(2,398)						2,398
Ending Balance, Noncontrolling Interest at Mar. 31, 2014	342,997						215,339	127,658
Ending Balance, Parent at Mar. 31, 2014	$ 10,376,561	$ 50,000	$ 3,611	$ 8,541,046	$ 1,944,798	$ (162,894)