CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 431,642	$ 1,789,483
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	565,772	830,097
Amortization of deferred financing costs	8,554	15,864
Amortization of Intangible Assets	2,376	2,214
Amortization of discounts and premiums on debt	(8,750)	(37,612)
Amortization of deferred settlements on derivative instruments	12,205	15,683
Write-off of pursuit costs	2,067	3,969
Income Loss from Investments in Unconsolidated Entities Adjustment	10,201	57,749
Distributions from unconsolidated entities - return on capital	4,557	1,519
Net (gain) on sales of investment securities	(57)	(830)
Net (gain) on sales of land parcels	(1,846)	(12,179)
Net (gain) on sales of discontinued operations	(223)	(1,990,577)
Net (gain) on sales of real estate properties	(128,544)	0
Unrealized (gain) loss on derivative instruments	(66)	32
Compensation paid with Company Common Shares	24,647	29,019
Changes in assets and liabilities:
(Increase) decrease in deposits – restricted	(2,223)	4,152
Decrease in mortgage deposits	1,638	271
Decrease in other assets	3,854	7,315
Increase in accounts payable and accrued expenses	76,331	65,001
Increase (decrease) in accrued interest payable	8,163	(2,175)
(Decrease) in other liabilities	(173)	(5,427)
Increase (decrease) in security deposits	4,146	(6,475)
Net cash provided by operating activities	1,014,271	767,093
CASH FLOWS FROM INVESTING ACTIVITIES:
Payments to Acquire Businesses, Net of Cash Acquired	0	(4,000,875)
Investment in real estate – acquisitions	(404,658)	(108,308)
Investment in real estate - development/other	(380,691)	(256,965)
Improvements to real estate	(133,181)	(96,866)
Additions to non-real estate property	(2,446)	(3,359)
Interest capitalized for real estate and unconsolidated entities under development	(38,140)	(32,946)
Proceeds from disposition of real estate, net	224,538	4,434,708
Investments in unconsolidated entities	(14,568)	(59,363)
Proceeds From Distributions Received From Unconsolidated Subsidiaries	77,042	25,471
Proceeds from Sale of Available-for-sale Securities	57	828
Decrease in deposits on real estate acquisitions and investments, net	20,845	147,890
Decrease in mortgage deposits	560	7,623
Acquisition of Noncontrolling Interests – Partially Owned Properties	(5,501)	0
Net cash (used for) provided by investing activities	(656,143)	57,838
CASH FLOWS FROM FINANCING ACTIVITIES:
Loan and bond acquisition costs	(10,598)	(18,254)
Mortgage Deposits	(5,557)	(3,769)
Mortgage notes payable:
Proceeds from Issuance of Long-term Debt	0	5,951
Lump sum payoffs	(63,772)	(701,762)
Scheduled principal repayments	(8,919)	(9,527)
Notes, net:
Proceeds from Notes Payable	1,194,278	1,245,550
Lump sum payoffs	(1,250,000)	(400,000)
Line of Credit Facility:
Proceeds	5,324,000	8,413,000
Repayments	(4,993,000)	(8,413,000)
(Payments on) settlement of derivative instruments	(758)	(44,013)
Proceeds from Employee Stock Purchase Plan	2,728	2,973
Proceeds from exercise of options	56,554	16,044
Payments for Repurchase of Common Stock	(1,777)	0
Payment of offering costs	0	(954)
Other financing activities, net	(33)	(33)
Contributions - Noncontrolling Interests - Partially Owned Properties	5,684	11,520
Contributions - Noncontrolling Interests - Operating Partnership	3	5
Distributions:
Common Shares	(595,564)	(537,464)
Preferred Shares	(3,109)	(3,109)
Noncontrolling Interests – Operating Partnership	(23,582)	(22,216)
Noncontrolling Interests – Partially Owned Properties	(6,762)	(5,702)
Net cash (used for) financing activities	(380,184)	(464,760)
Net (decrease) increase in cash and cash equivalents	(22,056)	360,171
Cash and cash equivalents, beginning of period	53,534	612,590
Cash and cash equivalents, end of period	31,478	972,761
SUPPLEMENTAL INFORMATION:
Cash paid for interest, net of amounts capitalized	335,646	451,495
Net cash paid for income and other taxes	866	1,064
AmortizationOfDeferredFinancingCosts [Abstract]
Amortization Of Deferred Financing Costs Investment In Real Estate Net	0	(152)
Amortization Of Deferred Financing Costs Deferred Financing Costs Net	8,554	16,016
Amortization of discounts and premiums on debt:
Mortgage notes payable	(10,515)	(39,232)
Notes, net	1,765	1,620
Amortization of deferred settlements on derivative instruments:
Other liabilities	(401)	(401)
Losses reclassified into earnings from other comprehensive income	12,606	16,084
Loss From Investments In Unconsolidated Entities [Abstract]
Income Loss From Equity Method Investments Merger	7,684	51,907
Other Liabilities Loss From Investments in unconsolidated entities	2,517	5,842
Distributions from unconsolidated entities return on capital [Abstract]
Distributions from unconsolidated entities investments in unconsolidated entities	4,399	1,519
Distributions from unconsolidated entities other liabilities	158	0
Unrealized (gain) loss on derivative instruments:
Other assets	11,409	(10,609)
Notes, net	(2,485)	(1,523)
Other liabilities	12,794	3,427
Unrealized holding (losses) gains arising during the period	(21,784)	8,737
Acquisition of Archstone, net of cash acquired [Abstract]
Acquisition of Archstone Investment in Real Estate Net	39,929	(8,710,242)
Acquisition of Archstone Investments in Unconsolidated Entities	(33,993)	(217,092)
Acquisition of Archstone Deposits Restricted	0	(474)
Acquisition of Archstone Escrow Deposits Mortgage	0	(35,897)
Acquisition of Archstone Deferred Financing Costs	0	(25,780)
Acquisition of Archstone Other Assets	(2,586)	(203,295)
Acquisition of Archstone Mortgage Notes Payable	0	3,076,876
Acquisition of Archstone Accounts Payable And Accrued Liabilities	(146)	17,576
Acqusition of Archstone Interest Payable	0	11,305
Acquisition of Archstone Other Liabilities	(3,204)	117,068
Acquisition of Archstone Security Deposits	0	10,949
Acquisition of Archstone Common Shares Issued	0	1,929,868
Acquisition of Archstone Noncontrolling Interests Partially Owned Properties	0	28,263
Interest capitalized for real estate and unconsolidated entities under development:
Investment in real estate, net	(38,086)	(31,648)
Investments in unconsolidated entities	(54)	(1,298)
Investments in unconsolidated entities [Abstract]
Investments in unconsolidated entities	(5,118)	(9,317)
Investments in unconsolidated entities other liabilities	(9,450)	(50,046)
Other:
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax	$ 466	$ 789