CONSOLIDATED STATEMENT OF CHANGES IN EQUITY (USD $) In Thousands, unless otherwise specified	Total	PREFERRED SHARES	COMMON SHARES, $0.01 PAR VALUE	PAID IN CAPITAL	RETAINED EARNINGS	ACCUMULATED OTHER COMPREHENSIVE (LOSS) INCOME	OPERATING PARTNERSHIP	Partially Owned Properties [Member]
Beginning Balance, Noncontrolling Interest at Dec. 31, 2012	$ 237,294						$ 159,606	$ 77,688
Beginning Balance, Parent at Dec. 31, 2012	7,289,813	50,000	3,251	6,542,355	887,355	(193,148)
Common Share Issuance:
Conversion of OP Units held by Noncontrolling Interests into OP Units held by General Partner				1,203			(1,203)
Issuance of Common Shares			345	1,929,523
Exercise of share options			5	16,039
Stock Issued During Period, Value, Employee Stock Purchase Plan			1	2,972
Adjustments to Additional Paid in Capital, Share-based Compensation, Restricted Stock Unit or Restricted Stock Award, Requisite Service Period Recognition			2	10,248
Share-based employee compensation expense:
Share options				8,684
ESPP discount				557
Offering costs				(954)
Supplemental Executive Retirement Plan (SERP)				(439)
Change in market value	(69,344)			69,344
Adjustment for Noncontrolling Interests ownership in Operating Partnership				(36,710)			36,710
Net income attributable to controlling interests	1,719,637				1,719,637
Common Share distributions					(432,280)
Dividends, Preferred Stock, Cash					(3,109)
Other comprehensive income (loss) - derivative instruments:
Unrealized holding gains (losses) arising during the period	8,737					8,737
Losses reclassified into earnings from other comprehensive income	(16,084)					16,084
Other comprehensive income (loss) - other instruments:
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Net of Tax	554					554
(Gain) Loss on Sale of Securities, Net	(830)					(830)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax	(789)					(789)
Issuance of LTIP Units to Noncontrolling Interests							5
Equity Compensation associated with Noncontrolling Interests							11,542
Net (Income) Attributable to Noncontrolling Interest	70,947						70,947	(1,101)
Contributions by Noncontrolling Interests	11,520							11,520
Archstone Acquisition Noncontrolling Interests Partially Owned Properties								28,263
Distributions to Noncontrolling Interests							(17,060)	(5,735)
Change in carrying value	47,029						(47,029)
Ending Balance, Noncontrolling Interest at Sep. 30, 2013	324,153						213,518	110,635
Ending Balance, Parent at Sep. 30, 2013	$ 10,598,637	$ 50,000	$ 3,604	$ 8,542,822	$ 2,171,603	$ (169,392)