CONSOLIDATED BALANCE SHEETS OF ERP OPERATING LIMITED PARTNERSHIP (USD $)	Dec. 31, 2013	Dec. 31, 2012
Investment in real estate
Land	$ 6,192,512,000	$ 4,554,912,000
Depreciable property	19,226,047,000	15,711,944,000
Projects under development	988,867,000	387,750,000
Land held for development	393,522,000	353,823,000
Real Estate Investment Property, at Cost	26,800,948,000	21,008,429,000
Real Estate Investment Property, Accumulated Depreciation	(4,807,709,000)	(4,912,221,000)
Investment in real estate, net	21,993,239,000	16,096,208,000
Cash and cash equivalents	53,534,000	612,590,000
Investments in unconsolidated entities	178,526,000	17,877,000
Deposits - restricted	103,567,000	250,442,000
Escrow deposits - mortgage	42,636,000	9,129,000
Deferred financing costs, net	58,486,000	44,382,000
Other assets	404,557,000	170,372,000
Total assets	22,834,545,000	17,201,000,000
Liabilities:
Mortgage notes payable	5,174,166,000	3,898,369,000
Notes, net	5,477,088,000	4,630,875,000
Lines of credit	115,000,000	0
Accounts payable and accrued expenses	118,791,000	38,372,000
Accrued interest payable	78,309,000	76,223,000
Other liabilities	347,748,000	304,518,000
Security deposits	71,592,000	66,988,000
Distributions payable	243,511,000	260,176,000
Total liabilities	11,626,205,000	9,275,521,000
Partners' Capital:
Accumulated other comprehensive (loss)	(155,162,000)	(193,148,000)
Noncontrolling Interests - Partially Owned Properties	126,583,000	77,688,000
Total liabilities and equity	22,834,545,000	17,201,000,000
OPERATING PARTNERSHIP
Investment in real estate
Land	6,192,512,000	4,554,912,000
Depreciable property	19,226,047,000	15,711,944,000
Projects under development	988,867,000	387,750,000
Land held for development	393,522,000	353,823,000
Real Estate Investment Property, at Cost	26,800,948,000	21,008,429,000
Real Estate Investment Property, Accumulated Depreciation	(4,807,709,000)	(4,912,221,000)
Investment in real estate, net	21,993,239,000	16,096,208,000
Cash and cash equivalents	53,534,000	612,590,000
Investments in unconsolidated entities	178,526,000	17,877,000
Deposits - restricted	103,567,000	250,442,000
Escrow deposits - mortgage	42,636,000	9,129,000
Deferred financing costs, net	58,486,000	44,382,000
Other assets	404,557,000	170,372,000
Total assets	22,834,545,000	17,201,000,000
Liabilities:
Mortgage notes payable	5,174,166,000	3,898,369,000
Notes, net	5,477,088,000	4,630,875,000
Lines of credit	115,000,000	0
Accounts payable and accrued expenses	118,791,000	38,372,000
Accrued interest payable	78,309,000	76,223,000
Other liabilities	347,748,000	304,518,000
Security deposits	71,592,000	66,988,000
Distributions payable	243,511,000	260,176,000
Total liabilities	11,626,205,000	9,275,521,000
Redeemable Limited Partners	363,144,000	398,372,000
Partners' Capital:
Preference Units	50,000,000	50,000,000
General Partner	10,612,363,000	7,432,961,000
Limited Partners	211,412,000	159,606,000
Accumulated other comprehensive (loss)	(155,162,000)	(193,148,000)
Total partners' capital	10,718,613,000	7,449,419,000
Noncontrolling Interests - Partially Owned Properties	126,583,000	77,688,000
Total capital	10,845,196,000	7,527,107,000
Total liabilities and equity	$ 22,834,545,000	$ 17,201,000,000