Investments in Real Estate Entities (Details 3) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Feb. 27, 2013
Assets:
Real estate, net	$ 1,392,833	$ 1,617,627
Other assets (1)	57,044	68,693
Total assets	1,449,877	1,686,320
Liabilities and partners' capital:
Mortgage notes payable and credit facility (1)	947,205	976,531
Other liabilities	20,471	23,130
Partners' capital	482,201	686,659
Total liabilities and partners' capital	1,449,877	1,686,320
Combined summary of the operating results of the accounted for using the equity method
Rental and other income	173,578	198,939	$ 212,994
Operating and other expenses	(67,962)	(80,301)	(86,434)
Gain on sale of real estate	98,899	333,221	96,152
Interest expense, net	(45,517)	(61,458)	(61,404)
Depreciation expense	(45,324)	(52,116)	(61,002)
Net income	113,674	338,285	100,306
Costs in excess of equity in underlying net assets of the respective investments	40,978	43,709
Summary of the Company's equity in income of unconsolidated entities
Equity in income (loss) of unconsolidated entities	70,018	148,766	(11,154)
Business Combination, Acquisition Related Costs	6,822	(3,717)	45,050
Land held for development	484,377	180,516
Fund I
Combined summary of the operating results of the accounted for using the equity method
Gain on sale of real estate		944	11,484
Summary of the Company's equity in income of unconsolidated entities
Equity in income (loss) of unconsolidated entities	871	475	10,924
Fund II
Combined summary of the operating results of the accounted for using the equity method
Gain on sale of real estate	29,726	21,624	2,790
Summary of the Company's equity in income of unconsolidated entities
Equity in income (loss) of unconsolidated entities	32,211	24,808	6,206
US Fund
Summary of the Company's equity in income of unconsolidated entities
Equity in income (loss) of unconsolidated entities	2,052	342	(661)
ACJV
Summary of the Company's equity in income of unconsolidated entities
Equity in income (loss) of unconsolidated entities	511	1,579	2,569
CVP I, LLC
Combined summary of the operating results of the accounted for using the equity method
Gain on sale of real estate		50,478
Summary of the Company's equity in income of unconsolidated entities
Equity in income (loss) of unconsolidated entities	1,812	113,127	5,783
Equity in income of unconsolidated entities relating to the Company's recognition of promoted interest	1,289	61,218	5,527
MVPI LLC
Combined summary of the operating results of the accounted for using the equity method
Payments for (Proceeds from) Other Real Estate Partnerships	21,340
Summary of the Company's equity in income of unconsolidated entities
Equity in income (loss) of unconsolidated entities	22,453	1,651	1,137
Equity in income of unconsolidated entities relating to the Company's recognition of promoted interest		930	516
Brandywine
Summary of the Company's equity in income of unconsolidated entities
Equity in income (loss) of unconsolidated entities	(1,474)	828	661
Arna Valley View LP
Summary of the Company's equity in income of unconsolidated entities
Equity in income (loss) of unconsolidated entities	0	2,406	0
Residual JV
Summary of the Company's equity in income of unconsolidated entities
Equity in income (loss) of unconsolidated entities	11,582	3,547	(38,332)
Avalon Del Rey LLC
Summary of the Company's equity in income of unconsolidated entities
Equity in income (loss) of unconsolidated entities	0	0	181
Juanita Village
Summary of the Company's equity in income of unconsolidated entities
Equity in income (loss) of unconsolidated entities	$ 0	3	378
Sheepshead Bay [Member]
Summary of the Company's equity in income of unconsolidated entities
Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage	70.00%
Variable Interest Entity, Ownership Interest by Partner	30.00%
Due from Related Parties	$ 8,126
Archstone Enterprise LP
Equity method investment
Business Acquisition, Percentage of Voting Interests Acquired				40.00%
Acquired Real Estate [Member]
Summary of the Company's equity in income of unconsolidated entities
Business Combination, Acquisition Related Costs	$ 3,806	$ (7,681)	$ 44,052
Equity Residential and its Operating Partnership and ERP Operating Limited Partnership [Member] | Archstone Enterprise LP
Equity method investment
Business Acquisition, Percentage of Voting Interests Acquired				60.00%