Investments in Partially Owned Entities (Details) (USD $)	12 Months Ended			22 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2014	Dec. 31, 2011
Partially Owned Property Balance Sheet Schedule
Partially Owned Consolidated Properties	19			19
Partially Owned Unconsolidated Properties	3			3
Partially Owned Consolidated Units	3,771			3,771
Partially Owned Unconsolidated Units	1,281			1,281
ASSETS
Investment in real estate	$ 27,675,383,000	$ 26,800,948,000		$ 27,675,383,000
Accumulated depreciation	5,432,805,000	4,807,709,000		5,432,805,000
Investment in real estate, net	22,242,578,000	21,993,239,000		22,242,578,000
Cash and cash equivalents	40,080,000	53,534,000	612,590,000	40,080,000	383,921,000
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures	105,434,000	178,526,000		105,434,000
Restricted Cash and Cash Equivalents	72,303,000	103,567,000		72,303,000
Deferred financing costs, net	58,380,000	58,486,000		58,380,000
Other assets	383,754,000	404,557,000		383,754,000
Total assets	22,950,614,000	22,834,545,000		22,950,614,000
LIABILITIES AND EQUITY
Secured Debt	5,086,515,000	5,174,166,000		5,086,515,000
Accounts Payable And Accrued Liabilities Current And Noncurrent Other Than Interest And Dividend Payable	153,590,000	118,791,000		153,590,000
Accrued interest payable	89,540,000	78,309,000		89,540,000
Other liabilities	389,915,000	347,748,000		389,915,000
Security Deposit Liability	75,633,000	71,592,000		75,633,000
Total liabilities	11,742,105,000	11,626,205,000		11,742,105,000
Noncontrolling Interests - Partially Owned Properties	124,909,000	126,583,000		124,909,000
Total liabilities and equity	22,950,614,000	22,834,545,000		22,950,614,000
Partially Owned Property Income Statement Schedule
Operating revenue	2,614,748,000	2,387,702,000	1,747,502,000
Depreciation	758,861,000	978,973,000	560,669,000
General and administrative/other	50,948,000	62,179,000	47,233,000
Operating (loss) income	921,375,000	512,322,000	514,093,000
Interest and other income	4,462,000	5,283,000	151,060,000
Interest:
Expense incurred, net	457,191,000	586,854,000	455,236,000
Amortization of deferred financing costs	(11,088,000)	(22,197,000)	(21,295,000)
(Loss) income before income and other taxes and (loss) from investments in unconsolidated entities	448,485,000	(121,076,000)	160,826,000
Income and other tax (expense) benefit	(1,394,000)	(1,169,000)	(514,000)
(Loss) from investments in unconsolidated entities	(7,952,000)	(58,156,000)	(14,000)
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	658,683,000	1,905,353,000	881,204,000
Joint Venture Partner Ownership Percentage	80.00%			80.00%
Investments In Partially Owned Entities (Textuals) [Abstract]
Disposed Properties	11	94
Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax	179,000	2,036,505,000	548,278,000
Disposed Units	3,480	29,180
Equity Method Investment, Ownership Percentage	20.00%			20.00%
Debt Instrument, Maturity Date		Sep. 01, 2014
Distributions from unconsolidated entities – return of capital	103,793,000	25,471,000	0
Preferred Interests		65,000,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets	498,640,000	108,000,000		498,640,000
Investment in Joint Venture	336,900,000			336,900,000
Number of Joint Ventures	2			2
Partners Payments To Acquire Equity Method Investments	40,100,000
Consolidated Development Projects Held for and or Under Development [Member]
Partially Owned Property Balance Sheet Schedule
Partially Owned Consolidated Properties	0			0
Partially Owned Consolidated Units	0			0
ASSETS
Investment in real estate	340,740,000			340,740,000
Accumulated depreciation	0			0
Investment in real estate, net	340,740,000			340,740,000
Cash and cash equivalents	0			0
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures	0			0
Restricted Cash and Cash Equivalents	22,706,000			22,706,000
Deferred financing costs, net	0			0
Other assets	6,658,000			6,658,000
Total assets	370,104,000			370,104,000
LIABILITIES AND EQUITY
Secured Debt	0			0
Accounts Payable And Accrued Liabilities Current And Noncurrent Other Than Interest And Dividend Payable	13,307,000			13,307,000
Accrued interest payable	0			0
Other liabilities	69,000			69,000
Security Deposit Liability	25,000			25,000
Total liabilities	13,401,000			13,401,000
Noncontrolling Interests - Partially Owned Properties	117,350,000			117,350,000
Parent Equity Interest	239,353,000			239,353,000
Total Equity Interest	356,703,000			356,703,000
Total liabilities and equity	370,104,000			370,104,000
Partially Owned Property Income Statement Schedule
Operating revenue	22,000
Operating Expenses	91,000
Net operating (loss) income	(69,000)
Depreciation	0
General and administrative/other	1,000
Operating (loss) income	(70,000)
Interest and other income	0
Other expenses	0
Interest:
Expense incurred, net	0
Amortization of deferred financing costs	0
(Loss) income before income and other taxes and (loss) from investments in unconsolidated entities	(70,000)
Income and other tax (expense) benefit	0
(Loss) from investments in unconsolidated entities	0
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	(70,000)
Consolidated Operating [Domain]
Partially Owned Property Balance Sheet Schedule
Partially Owned Consolidated Properties	19			19
Partially Owned Consolidated Units	3,771			3,771
ASSETS
Investment in real estate	682,374,000			682,374,000
Accumulated depreciation	194,481,000			194,481,000
Investment in real estate, net	487,893,000			487,893,000
Cash and cash equivalents	19,338,000			19,338,000
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures	51,979,000			51,979,000
Restricted Cash and Cash Equivalents	300,000			300,000
Deferred financing costs, net	2,141,000			2,141,000
Other assets	26,609,000			26,609,000
Total assets	588,260,000			588,260,000
LIABILITIES AND EQUITY
Secured Debt	360,479,000			360,479,000
Accounts Payable And Accrued Liabilities Current And Noncurrent Other Than Interest And Dividend Payable	1,611,000			1,611,000
Accrued interest payable	1,283,000			1,283,000
Other liabilities	885,000			885,000
Security Deposit Liability	1,954,000			1,954,000
Total liabilities	366,212,000			366,212,000
Noncontrolling Interests - Partially Owned Properties	7,559,000			7,559,000
Parent Equity Interest	214,489,000			214,489,000
Total Equity Interest	222,048,000			222,048,000
Total liabilities and equity	588,260,000			588,260,000
Partially Owned Property Income Statement Schedule
Operating revenue	88,157,000
Operating Expenses	25,674,000
Net operating (loss) income	62,483,000
Depreciation	21,679,000
General and administrative/other	116,000
Operating (loss) income	40,688,000
Interest and other income	11,000
Other expenses	(54,000)
Interest:
Expense incurred, net	(15,626,000)
Amortization of deferred financing costs	355,000
(Loss) income before income and other taxes and (loss) from investments in unconsolidated entities	24,664,000
Income and other tax (expense) benefit	(36,000)
(Loss) from investments in unconsolidated entities	(1,593,000)
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	23,035,000
Consolidated Total [Domain]
Partially Owned Property Balance Sheet Schedule
Partially Owned Consolidated Properties	19			19
Partially Owned Consolidated Units	3,771			3,771
ASSETS
Investment in real estate	1,023,114,000			1,023,114,000
Accumulated depreciation	194,481,000			194,481,000
Investment in real estate, net	828,633,000			828,633,000
Cash and cash equivalents	19,338,000			19,338,000
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures	51,979,000			51,979,000
Restricted Cash and Cash Equivalents	23,006,000			23,006,000
Deferred financing costs, net	2,141,000			2,141,000
Other assets	33,267,000			33,267,000
Total assets	958,364,000			958,364,000
LIABILITIES AND EQUITY
Secured Debt	360,479,000			360,479,000
Accounts Payable And Accrued Liabilities Current And Noncurrent Other Than Interest And Dividend Payable	14,918,000			14,918,000
Accrued interest payable	1,283,000			1,283,000
Other liabilities	954,000			954,000
Security Deposit Liability	1,979,000			1,979,000
Total liabilities	379,613,000			379,613,000
Noncontrolling Interests - Partially Owned Properties	124,909,000			124,909,000
Parent Equity Interest	453,842,000			453,842,000
Total Equity Interest	578,751,000			578,751,000
Total liabilities and equity	958,364,000			958,364,000
Partially Owned Property Income Statement Schedule
Operating revenue	88,179,000
Operating Expenses	25,765,000
Net operating (loss) income	62,414,000
Depreciation	21,679,000
General and administrative/other	117,000
Operating (loss) income	40,618,000
Interest and other income	11,000
Other expenses	(54,000)
Interest:
Expense incurred, net	(15,626,000)
Amortization of deferred financing costs	355,000
(Loss) income before income and other taxes and (loss) from investments in unconsolidated entities	24,594,000
Income and other tax (expense) benefit	(36,000)
(Loss) from investments in unconsolidated entities	(1,593,000)
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	22,965,000
Unconsolidated Completed, Not Stabilized [Domain]
Partially Owned Property Balance Sheet Schedule
Partially Owned Unconsolidated Properties	1			1
Partially Owned Unconsolidated Units	444			444
ASSETS
Investment in real estate	155,376,000			155,376,000
Accumulated depreciation	6,921,000			6,921,000
Investment in real estate, net	148,455,000			148,455,000
Cash and cash equivalents	2,684,000			2,684,000
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures	0			0
Restricted Cash and Cash Equivalents	0			0
Deferred financing costs, net	0			0
Other assets	529,000			529,000
Total assets	151,668,000			151,668,000
LIABILITIES AND EQUITY
Secured Debt	96,793,000			96,793,000
Accounts Payable And Accrued Liabilities Current And Noncurrent Other Than Interest And Dividend Payable	769,000			769,000
Accrued interest payable	464,000			464,000
Other liabilities	294,000			294,000
Security Deposit Liability	173,000			173,000
Total liabilities	98,493,000			98,493,000
Noncontrolling Interests - Partially Owned Properties	47,223,000			47,223,000
Parent Equity Interest	5,952,000			5,952,000
Total Equity Interest	53,175,000			53,175,000
Total liabilities and equity	151,668,000			151,668,000
Partially Owned Property Income Statement Schedule
Operating revenue	10,182,000
Operating Expenses	3,781,000
Net operating (loss) income	6,401,000
Depreciation	6,512,000
General and administrative/other	1,000
Operating (loss) income	(112,000)
Interest and other income	0
Other expenses	0
Interest:
Expense incurred, net	(5,296,000)
Amortization of deferred financing costs	0
(Loss) income before income and other taxes and (loss) from investments in unconsolidated entities	(5,408,000)
Income and other tax (expense) benefit	(7,000)
(Loss) from investments in unconsolidated entities	0
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	(5,415,000)
Unconsolidated Operating [Domain]
Partially Owned Property Balance Sheet Schedule
Partially Owned Unconsolidated Properties	2			2
Partially Owned Unconsolidated Units	837			837
ASSETS
Investment in real estate	134,669,000			134,669,000
Accumulated depreciation	11,391,000			11,391,000
Investment in real estate, net	123,278,000			123,278,000
Cash and cash equivalents	3,172,000			3,172,000
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures	0			0
Restricted Cash and Cash Equivalents	214,000			214,000
Deferred financing costs, net	8,000			8,000
Other assets	691,000			691,000
Total assets	127,363,000			127,363,000
LIABILITIES AND EQUITY
Secured Debt	78,628,000			78,628,000
Accounts Payable And Accrued Liabilities Current And Noncurrent Other Than Interest And Dividend Payable	259,000			259,000
Accrued interest payable	227,000			227,000
Other liabilities	671,000			671,000
Security Deposit Liability	300,000			300,000
Total liabilities	80,085,000			80,085,000
Noncontrolling Interests - Partially Owned Properties	43,655,000			43,655,000
Parent Equity Interest	3,623,000			3,623,000
Total Equity Interest	47,278,000			47,278,000
Total liabilities and equity	127,363,000			127,363,000
Partially Owned Property Income Statement Schedule
Operating revenue	15,160,000
Operating Expenses	6,818,000
Net operating (loss) income	8,342,000
Depreciation	5,800,000
General and administrative/other	209,000
Operating (loss) income	2,333,000
Interest and other income	0
Other expenses	0
Interest:
Expense incurred, net	(3,831,000)
Amortization of deferred financing costs	2,000
(Loss) income before income and other taxes and (loss) from investments in unconsolidated entities	(1,500,000)
Income and other tax (expense) benefit	0
(Loss) from investments in unconsolidated entities	0
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	(1,500,000)
Unconsolidated Total [Domain]
Partially Owned Property Balance Sheet Schedule
Partially Owned Unconsolidated Properties	3			3
Partially Owned Unconsolidated Units	1,281			1,281
ASSETS
Investment in real estate	290,045,000			290,045,000
Accumulated depreciation	18,312,000			18,312,000
Investment in real estate, net	271,733,000			271,733,000
Cash and cash equivalents	5,856,000			5,856,000
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures	0			0
Restricted Cash and Cash Equivalents	214,000			214,000
Deferred financing costs, net	8,000			8,000
Other assets	1,220,000			1,220,000
Total assets	279,031,000			279,031,000
LIABILITIES AND EQUITY
Secured Debt	175,421,000			175,421,000
Accounts Payable And Accrued Liabilities Current And Noncurrent Other Than Interest And Dividend Payable	1,028,000			1,028,000
Accrued interest payable	691,000			691,000
Other liabilities	965,000			965,000
Security Deposit Liability	473,000			473,000
Total liabilities	178,578,000			178,578,000
Noncontrolling Interests - Partially Owned Properties	90,878,000			90,878,000
Parent Equity Interest	9,575,000			9,575,000
Total Equity Interest	100,453,000			100,453,000
Total liabilities and equity	279,031,000			279,031,000
Partially Owned Property Income Statement Schedule
Operating revenue	25,342,000
Operating Expenses	10,599,000
Net operating (loss) income	14,743,000
Depreciation	12,312,000
General and administrative/other	210,000
Operating (loss) income	2,221,000
Interest and other income	0
Other expenses	0
Interest:
Expense incurred, net	(9,127,000)
Amortization of deferred financing costs	2,000
(Loss) income before income and other taxes and (loss) from investments in unconsolidated entities	(6,908,000)
Income and other tax (expense) benefit	(7,000)
(Loss) from investments in unconsolidated entities	0
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	(6,915,000)
Archstone Transaction [Member]
Interest:
Liquidation Value Preferred Interests	74,600,000			74,600,000
Investments In Partially Owned Entities (Textuals) [Abstract]
Distributions from unconsolidated entities – return of capital	79,600,000			98,500,000
Residual JV [Domain]
Investments In Partially Owned Entities (Textuals) [Abstract]
Initial Basis of Real Estate, Unconsolidated		(147,600,000)
Joint Venture Partner [Member]
LIABILITIES AND EQUITY
Noncontrolling Interests - Partially Owned Properties	117,400,000			117,400,000
Investments In Partially Owned Entities (Textuals) [Abstract]
Land purchase price	57,900,000			57,900,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets	75,700,000			75,700,000
Company's Portion [Member]
Investments In Partially Owned Entities (Textuals) [Abstract]
Land purchase price	76,100,000			76,100,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets	102,500,000			102,500,000
Nexus Sawgrass [Member]
LIABILITIES AND EQUITY
Secured Debt	48,600,000			48,600,000
Investments In Partially Owned Entities (Textuals) [Abstract]
Debt Instrument, Interest Rate, Stated Percentage	5.60%			5.60%
Debt Instrument, Maturity Date	Jan. 01, 2021
Project Cost	78,600,000			78,600,000
Maximum Debt Commitment	48,700,000			48,700,000
Domain [Member]
LIABILITIES AND EQUITY
Secured Debt	96,800,000			96,800,000
Investments In Partially Owned Entities (Textuals) [Abstract]
Debt Instrument, Interest Rate, Stated Percentage	5.75%			5.75%
Debt Instrument, Maturity Date	Jan. 01, 2022
Project Cost	155,800,000			155,800,000
Maximum Debt Commitment	98,600,000			98,600,000
Unconsolidated Properties [Member]
Investments In Partially Owned Entities (Textuals) [Abstract]
Disposed Properties	1
Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax	4,900,000
Archstone Transaction [Member]
Interest:
Business Acquisition, Percentage of Voting Interests Acquired	60.00%			60.00%
Joint Venture Partner Ownership Percentage	40.00%			40.00%
Company's Portion [Member]
Investments In Partially Owned Entities (Textuals) [Abstract]
Preferred Interests		39,000,000
Wisconsin Place [Domain]
Partially Owned Property Balance Sheet Schedule
Partially Owned Consolidated Units		432
ASSETS
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures		56,500,000
Interest:
Business Acquisition, Percentage of Voting Interests Acquired		75.00%
Investments In Partially Owned Entities (Textuals) [Abstract]
Initial Basis of Real Estate, Consolidated		198,500,000
Waterton Tenside [Domain]
Partially Owned Property Balance Sheet Schedule
Partially Owned Unconsolidated Units		336
LIABILITIES AND EQUITY
Secured Debt		30,000,000
Investments In Partially Owned Entities (Textuals) [Abstract]
Equity Method Investment, Ownership Percentage		20.00%
Debt Instrument, Interest Rate, Stated Percentage		3.66%
Debt Instrument, Maturity Date		Dec. 01, 2018
Initial Basis of Real Estate, Unconsolidated		5,100,000
Joint Venture Partner [Member]
Investments In Partially Owned Entities (Textuals) [Abstract]
Disposed Properties	1		2
Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax	$ 1,100,000		$ 21,300,000
Disposed Units	388		441