CONSOLIDATED STATEMENTS OF OPERATIONS OF ERP OPERATING LIMITED PARTNERSHIP - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
REVENUES
Rental income	$ 2,736,578	$ 2,605,311	$ 2,378,004
Fee and asset management	8,387	9,437	9,698
Total revenues	2,744,965	2,614,748	2,387,702
EXPENSES
Property and maintenance	479,160	473,098	449,427
Real estate taxes and insurance	339,802	325,401	293,999
Property management	81,185	79,636	84,342
Fee and asset management	5,021	5,429	6,460
Depreciation	765,895	758,861	978,973
General and administrative	65,082	50,948	62,179
Total expenses	1,736,145	1,693,373	1,875,380
Operating income	1,008,820	921,375	512,322
Interest and other income	7,372	4,462	5,283
Other expenses	(2,942)	(9,073)	(29,630)
Interest:
Expense incurred, net	(444,069)	(457,191)	(586,854)
Amortization of deferred financing costs	(10,801)	(11,088)	(22,197)
Income (loss) before income and other taxes, income (loss) from investments in unconsolidated entities, net gain (loss) on sales of real estate properties and land parcels and discontinued operations	558,380	448,485	(121,076)
Income and other tax (expense) benefit	(917)	(1,394)	(1,169)
Income (loss) from investments in unconsolidated entities	15,025	(7,952)	(58,156)
Net gain on sales of real estate properties	335,134	212,685	0
Net (loss) gain on sales of land parcels	(1)	5,277	12,227
Income (loss) from continuing operations	907,621	657,101	(168,174)
Discontinued operations, net	397	1,582	2,073,527
Net income	908,018	658,683	1,905,353
Net (income) loss attributable to Noncontrolling Interests – Partially Owned Properties	(3,657)	(2,544)	538
Net income attributable to controlling interests	870,120	631,308	1,830,613
ALLOCATION OF NET INCOME:
Premium on redemption of Preference Units	$ (3,486)	$ 0	$ 0
Earnings per Unit – basic:
Income (loss) from continuing operations available to Units	$ 2.37	$ 1.73	$ (0.47)
Net income available to Units	2.37	1.74	5.16
Earnings per Unit – diluted:
Income (loss) from continuing operations available to Units	2.36	1.72	(0.47)
Net income available to Units	$ 2.36	$ 1.73	$ 5.16
Weighted average Units outstanding	380,620	377,735	354,305
ERPOP [Member]
REVENUES
Rental income	$ 2,736,578	$ 2,605,311	$ 2,378,004
Fee and asset management	8,387	9,437	9,698
Total revenues	2,744,965	2,614,748	2,387,702
EXPENSES
Property and maintenance	479,160	473,098	449,427
Real estate taxes and insurance	339,802	325,401	293,999
Property management	81,185	79,636	84,342
Fee and asset management	5,021	5,429	6,460
Depreciation	765,895	758,861	978,973
General and administrative	65,082	50,948	62,179
Total expenses	1,736,145	1,693,373	1,875,380
Operating income	1,008,820	921,375	512,322
Interest and other income	7,372	4,462	5,283
Other expenses	(2,942)	(9,073)	(29,630)
Interest:
Expense incurred, net	(444,069)	(457,191)	(586,854)
Amortization of deferred financing costs	(10,801)	(11,088)	(22,197)
Income (loss) before income and other taxes, income (loss) from investments in unconsolidated entities, net gain (loss) on sales of real estate properties and land parcels and discontinued operations	558,380	448,485	(121,076)
Income and other tax (expense) benefit	(917)	(1,394)	(1,169)
Income (loss) from investments in unconsolidated entities	15,025	(7,952)	(58,156)
Net gain on sales of real estate properties	335,134	212,685	0
Net (loss) gain on sales of land parcels	(1)	5,277	12,227
Income (loss) from continuing operations	907,621	657,101	(168,174)
Discontinued operations, net	397	1,582	2,073,527
Net income	908,018	658,683	1,905,353
Net (income) loss attributable to Noncontrolling Interests – Partially Owned Properties	(3,657)	(2,544)	538
Net income attributable to controlling interests	904,361	656,139	1,905,891
ALLOCATION OF NET INCOME:
Preference Units	3,357	4,145	4,145
Premium on redemption of Preference Units	3,486	0	0
General Partner	863,277	627,163	1,826,468
Limited Partners	34,241	24,831	75,278
Net income available to Units	$ 897,518	$ 651,994	$ 1,901,746
Earnings per Unit – basic:
Income (loss) from continuing operations available to Units	$ 2.37	$ 1.73	$ (0.47)
Net income available to Units	$ 2.37	$ 1.74	$ 5.16
Weighted average Units outstanding	377,074	374,899	368,038
Earnings per Unit – diluted:
Income (loss) from continuing operations available to Units	$ 2.36	$ 1.72	$ (0.47)
Net income available to Units	$ 2.36	$ 1.73	$ 5.16
Weighted average Units outstanding	380,620	377,735	368,038
Distributions declared per Unit outstanding	$ 2.210	$ 2.000	$ 1.850