Derivatives and Hedging Activity (UNITED DOMINION REALTY, L.P.) Derivatives and Hedging Activity (UNITED DOMINION REALTY, L.P.) (Details 4) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Derivative [Line Items]
Derivative Liability		$ 4,965us-gaap_DerivativeLiabilities
Derivative, Collateral, Right to Reclaim Securities	(27)	0
Derivative Liability, Fair Value, Amount Offset Against Collateral	10,341	4,965
Derivative Liability Designated as Hedging Instrument, Fair Value	10,368	4,965
Derivative Liability, Not Subject to Master Netting Arrangement	0	0
Derivative, Collateral, Right to Reclaim Cash	0	0
United Dominion Reality L P [Member]
Derivative [Line Items]
Derivative Liability	918	2,731
Derivative, Collateral, Right to Reclaim Securities	0	0
Derivative Liability, Fair Value, Amount Offset Against Collateral	918	2,731
Derivative Liability Designated as Hedging Instrument, Fair Value	918	2,731
Derivative Liability, Not Subject to Master Netting Arrangement	0	0
Derivative, Collateral, Right to Reclaim Cash	$ 0	$ 0

Amount of right to receive cash collateral under master netting arrangements that have not been offset against derivative liabilities.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 20

-Section 55

-Paragraph 13

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Amount of right to receive securities collateral under master netting arrangements that have not been offset against derivative liabilities.

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Fair value, after offset of derivative asset, of financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, elected not to be and before offset against a right to receive collateral under a master netting arrangement. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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Fair value, after effects of master netting arrangements, of financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset offset against the right to receive collateral. Includes liabilities not subject to a master netting arrangement and not elected to be offset.

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Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities not subject to a master netting arrangement and not elected to be offset.

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Fair value of financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, not subject to a master netting arrangement.

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