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			1	1,429			(1,430)
Exercise of share options			8	25,677
Stock Issued During Period, Value, Employee Stock Purchase Plan				2,218
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			2	6,981
Share options				5,330
ESPP discount				587
Payments for Repurchase of Common Stock	(1,777)			(1,777)
Supplemental Executive Retirement Plan (SERP)				4,212
Acquisition Noncontrolling Interests Partially Owned Properties				(2,308)				(2,244)
Change in market value	(80,615)			(80,615)
Adjustment for Noncontrolling Interests ownership in Operating Partnership				4,146			(4,146)
Net income attributable to controlling interests	191,825				191,825
Common Share distributions					(361,279)
Dividends, Preferred Stock, Cash					(2,072)
Other comprehensive (loss) income – derivative instruments:
Unrealized holding (losses) arising during the period	(21,881)					(21,881)
Losses reclassified into earnings from other comprehensive income	(8,335)					8,335
Currency translation adjustments arising during the period	1,718					1,718
Issuance of LTIP Units to Noncontrolling Interests							3
Equity Compensation associated with Noncontrolling Interests							10,319
Net (Income) Attributable to Noncontrolling Interest	7,535						7,535	1,092
Contributions by Noncontrolling Interests	5,684							5,684
Distributions to Noncontrolling Interests							(14,364)	(5,272)
Change in carrying value							3,709
Ending Balance, Noncontrolling Interest at Jun. 30, 2014	338,881						213,038	125,843
Ending Balance, Parent at Jun. 30, 2014	$ 10,289,738	$ 50,000	$ 3,616	$ 8,527,380	$ 1,875,732	$ (166,990)