CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 200,452	$ 1,397,766
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	375,303	550,488
Amortization of deferred financing costs	5,926	11,529
Amortization of Intangible Assets	1,530	1,216
Amortization of discounts and premiums on debt	(5,876)	(23,031)
Amortization of deferred settlements on derivative instruments	8,068	11,830
Write-off of pursuit costs	1,492	3,365
Income Loss from Investments in Unconsolidated Entities Adjustment	9,025	54,540
Distributions from unconsolidated entities - return on capital	2,390	588
Net (gain) on sales of land parcels	(794)	(14,616)
Net (gain) on sales of discontinued operations	(224)	(1,588,874)
Net (gain) on sales of real estate properties	(14,903)	0
Unrealized (gain) loss on derivative instruments	(90)	24
Compensation paid with Company Common Shares	21,905	22,089
Changes in assets and liabilities:
(Increase) in deposits – restricted	(1,820)	(12,220)
Decrease in mortgage deposits	187	789
(Increase) in other assets	(7,745)	(4,695)
Increase in accounts payable and accrued expenses	38,951	25,956
Increase (decrease) in accrued interest payable	80	(1,396)
(Decrease) in other liabilities	(17,237)	(11,449)
Increase (decrease) in security deposits	2,916	(6,080)
Net cash provided by operating activities	619,536	417,819
CASH FLOWS FROM INVESTING ACTIVITIES:
Payments to Acquire Businesses, Net of Cash Acquired	0	(4,000,875)
Investment in real estate – acquisitions	(265,466)	(108,308)
Investment in real estate - development/other	(245,657)	(154,576)
Improvements to real estate	(76,912)	(57,253)
Additions to non-real estate property	(1,818)	(2,801)
Interest capitalized for real estate and unconsolidated entities under development	(25,037)	(20,006)
Proceeds from disposition of real estate, net	48,359	3,764,000
Investments in unconsolidated entities	(9,554)	(53,687)
Proceeds From Distributions Received From Unconsolidated Subsidiaries	64,669	0
Decrease in deposits on real estate acquisitions and investments, net	20,979	65,869
Decrease in mortgage deposits	760	5,089
Acquisition of Noncontrolling Interests – Partially Owned Properties	(5,501)	0
Net cash (used for) investing activities	(495,178)	(562,548)
CASH FLOWS FROM FINANCING ACTIVITIES:
Loan and bond acquisition costs	(10,881)	(18,006)
Mortgage Deposits	(3,580)	(2,208)
Mortgage notes payable:
Proceeds from Issuance of Long-term Debt	0	683
Lump sum payoffs	(3,064)	(697,897)
Scheduled principal repayments	(6,000)	(6,336)
Notes, net:
Proceeds from Notes Payable	1,194,277	1,245,550
Lump sum payoffs	(750,000)	(400,000)
Line of Credit Facility:
Proceeds	3,374,000	8,413,000
Repayments	(3,489,000)	(8,413,000)
(Payments on) settlement of derivative instruments	(733)	(44,013)
Proceeds from Employee Stock Purchase Plan	2,218	2,363
Proceeds from exercise of options	25,685	13,885
Payments for Repurchase of Common Stock	(1,777)	0
Payment of offering costs	0	(744)
Other financing activities, net	(33)	(33)
Contributions - Noncontrolling Interests - Partially Owned Properties	5,684	6,769
Contributions - Noncontrolling Interests - Operating Partnership	3	5
Distributions:
Common Shares	(414,843)	(393,347)
Preferred Shares	(2,072)	(1,036)
Noncontrolling Interests – Operating Partnership	(16,405)	(16,528)
Noncontrolling Interests – Partially Owned Properties	(5,239)	(4,404)
Net cash (used for) financing activities	(101,760)	(315,297)
Net increase (decrease) in cash and cash equivalents	22,598	(460,026)
Cash and cash equivalents, beginning of period	53,534	612,590
Cash and cash equivalents, end of period	76,132	152,564
SUPPLEMENTAL INFORMATION:
Cash paid for interest, net of amounts capitalized	226,785	319,992
Net cash paid for income and other taxes	843	1,028
AmortizationOfDeferredFinancingCosts [Abstract]
Amortization Of Deferred Financing Costs Investment In Real Estate Net	0	(1)
Amortization Of Deferred Financing Costs Deferred Financing Costs Net	5,926	11,530
Amortization of discounts and premiums on debt:
Mortgage notes payable	(7,011)	(24,083)
Notes, net	1,135	1,052
Amortization of deferred settlements on derivative instruments:
Other liabilities	(267)	(268)
Losses reclassified into earnings from other comprehensive income	8,335	12,098
Loss From Investments In Unconsolidated Entities [Abstract]
Income Loss From Equity Method Investments Merger	7,354	49,507
Other Liabilities Loss From Investments in unconsolidated entities	1,671	5,033
Distributions from unconsolidated entities return on capital [Abstract]
Distributions from unconsolidated entities investments in unconsolidated entities	2,285	588
Distributions from unconsolidated entities other liabilities	105	0
Unrealized (gain) loss on derivative instruments:
Other assets	10,611	(10,753)
Notes, net	1,452	(1,523)
Other liabilities	9,728	(37)
Unrealized holding (losses) gains arising during the period	(21,881)	12,337
Acquisition of Archstone, net of cash acquired [Abstract]
Acquisition of Archstone Investment in Real Estate Net	39,929	(8,713,217)
Acquisition of Archstone Investments in Unconsolidated Entities	(33,993)	(214,677)
Acquisition of Archstone Deposits Restricted	0	(474)
Acquisition of Archstone Escrow Deposits Mortgage	0	(35,898)
Acquisition of Archstone Deferred Financing Costs	0	(25,780)
Acquisition of Archstone Other Assets	(2,586)	(203,008)
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	11,256
Acquisition of Archstone Other Liabilities	(3,204)	117,391
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	(25,002)	(19,195)
Investments in unconsolidated entities	(35)	(811)
Investments in unconsolidated entities [Abstract]
Investments in unconsolidated entities	(2,354)	(4,371)
Investments in unconsolidated entities other liabilities	(7,200)	(49,316)
Other:
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax	$ (1,718)	$ (941)