2.4.0.82424401 - Disclosure - Capital Structure (UNITED DOMINION REALTY, L.P.) (Details)truefalseIn Thousands, except Share data, unless otherwise specifiedfalse1false falsefalseD2013Q2YTD_dei_LegalEntityAxis_udr_UnitedDominionRealityLPMemberhttp://www.sec.gov/CIK0000074208duration2013-01-01T00:00:002013-06-30T00:00:00sharesStandardhttp://www.xbrl.org/2003/instancesharesxbrli02false falsefalseI2012Q4_dei_LegalEntityAxis_udr_UnitedDominionRealityLPMemberhttp://www.sec.gov/CIK0000074208instant2012-12-31T00:00:000001-01-01T00:00:00sharesStandardhttp://www.xbrl.org/2003/instancesharesxbrli01true 3us-gaap_LimitedPartnersCapitalAccountLineItemsus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Limited Partners' Capital Account [Line Items]2false 4us-gaap_GeneralPartnersCapitalAccountUnitsOutstandingus-gaap_truenainstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse174957876174957876falsefalsefalse2falsefalsefalse00falsefalsefalsexbrli:sharesItemTypesharesThe number of general partner units outstanding.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 5 -Subparagraph (SAB TOPIC 4.F) -URI http://asc.fasb.org/extlink&oid=6959260&loc=d3e187171-122770 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 4 -Section F Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number 87-21 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Practice Bulletin (PB) -Number 14 -Paragraph 10 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. false1General Partnership units outstanding3false 4us-gaap_RedeemableNoncontrollingInterestEquityCommonCarryingAmountus-gaap_truecreditinstantfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1truefalsefalse237653000237653USD$falsetruefalse2truefalsefalse223418000223418USD$falsetruefalsexbrli:monetaryItemTypemonetaryAs of the reporting date, the carrying amount of noncontrolling interests which are redeemable by the (parent) entity (1) at a fixed or determinable price on a fixed or determinable date, (2) at the option of the holder of the noncontrolling interest, or (3) upon occurrence of an event that is not solely within the control of the (parent) entity. The noncontrolling interest holder's ownership (or holders' ownership) may be in the form of common shares (regardless of class), limited partnership units (regardless of class), non-preferential membership interests, or any other form of common equity regardless of investee entity legal form.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 480 -SubTopic 10 -Section S99 -Paragraph 3A -Subparagraph (12)(c) -URI http://asc.fasb.org/extlink&oid=14643745&loc=SL6540498-122764 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 480 -SubTopic 10 -Section S99 -Paragraph 3A -Subparagraph (16)(c) -URI http://asc.fasb.org/extlink&oid=14643745&loc=SL6540498-122764 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 480 -SubTopic 10 -Section S99 -Paragraph 3A -Subparagraph 15 -URI http://asc.fasb.org/extlink&oid=14643745&loc=SL6540498-122764 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 480 -SubTopic 10 -Section S99 -Paragraph 3A -Subparagraph 14 -URI http://asc.fasb.org/extlink&oid=14643745&loc=SL6540498-122764 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number D-98 -Paragraph 43 -Subparagraph b -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number D-98 -Paragraph 43 -Subparagraph c -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 7: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 27 -Subparagraph c -Appendix A false2Redeemable non-controlling interests in operating partnership4false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3false truefalseD2013Q2YTD_dei_LegalEntityAxis_udr_UnitedDominionRealityLPMemberhttp://www.sec.gov/CIK0000074208duration2013-01-01T00:00:002013-06-30T00:00:00falsefalseUnited Dominion Reality L.P. [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiudr_UnitedDominionRealityLPMemberdei_LegalEntityAxisexplicitMembersharesStandardhttp://www.xbrl.org/2003/instancesharesxbrli0nanafalse0United Dominion Reality L.P. [Member]5true 3us-gaap_LimitedPartnersCapitalAccountLineItemsus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Limited Partners' Capital Account [Line Items]6false 4us-gaap_GeneralPartnersCapitalAccountUnitsOutstandingus-gaap_truenainstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse110883110883falsefalsefalse2truefalsefalse110883110883falsefalsefalsexbrli:sharesItemTypesharesThe number of general partner units outstanding.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 5 -Subparagraph (SAB TOPIC 4.F) -URI http://asc.fasb.org/extlink&oid=6959260&loc=d3e187171-122770 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 4 -Section F Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number 87-21 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Practice Bulletin (PB) -Number 14 -Paragraph 10 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. false1General Partnership units outstanding7false 4us-gaap_LimitedPartnersCapitalAccountUnitsOutstandingus-gaap_truenainstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse184170370184170370falsefalsefalse2truefalsefalse184170370184170370falsefalsefalsexbrli:sharesItemTypesharesThe number of limited partner units outstanding.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 5 -Subparagraph (SAB TOPIC 4.F) -URI http://asc.fasb.org/extlink&oid=6959260&loc=d3e187171-122770 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 4 -Section F Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 272 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70434-108055 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number 87-21 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Practice Bulletin (PB) -Number 14 -Paragraph 10 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. false1Limited partnership units owned8false 4udr_LimitedPartnersCapitalAccountRequiredPeriodToBeOutstandingBeforeUnitIsRedeemableudr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse001 yearfalsefalsefalse2falsefalsefalse00falsefalsefalsexbrli:durationItemTypenaLimited Partners' Capital Account, Required Period To Be Outstanding Before Unit is RedeemableNo definition available.false0Limited Partners' Capital Account, Required Period To Be Outstanding Before Unit is Redeemable9false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse5false truefalseI2013Q2_dei_LegalEntityAxis_udr_UdrIncMemberhttp://www.sec.gov/CIK0000074208instant2013-06-30T00:00:000001-01-01T00:00:00falsefalseUDR, Inc. [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiudr_UdrIncMemberdei_LegalEntityAxisexplicitMembersharesStandardhttp://www.xbrl.org/2003/instancesharesxbrli0numberStandardhttp://www.xbrl.org/2003/instancepurexbrli0nanafalse0UDR, Inc. [Member]10true 3us-gaap_LimitedPartnersCapitalAccountLineItemsus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Limited Partners' Capital Account [Line Items]11false 4us-gaap_LimitedPartnersCapitalAccountUnitsOutstandingus-gaap_truenainstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse174846993174846993falsefalsefalse2truefalsefalse174775152174775152falsefalsefalsexbrli:sharesItemTypesharesThe number of limited partner units outstanding.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 5 -Subparagraph (SAB TOPIC 4.F) -URI http://asc.fasb.org/extlink&oid=6959260&loc=d3e187171-122770 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 4 -Section F Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 272 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70434-108055 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number 87-21 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Practice Bulletin (PB) -Number 14 -Paragraph 10 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. false1Limited partnership units owned12false 4udr_LimitedPartnersCapitalAccountUnitsOutstandingPercentageudr_falsenainstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truetruefalse0.9490.949falsefalsefalse2truetruefalse0.9490.949falsefalsefalsenum:percentItemTypepureLimited Partners Capital Account Units Outstanding Percentage.No definition available.false0Percentage of units13false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse7false truefalseI2013Q2_dei_LegalEntityAxis_udr_NonAffiliatedPartnersMemberhttp://www.sec.gov/CIK0000074208instant2013-06-30T00:00:000001-01-01T00:00:00falsefalseNon-affiliated Partners [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiudr_NonAffiliatedPartnersMemberdei_LegalEntityAxisexplicitMembersharesStandardhttp://www.xbrl.org/2003/instancesharesxbrli0numberStandardhttp://www.xbrl.org/2003/instancepurexbrli0nanafalse0Non-affiliated Partners [Member]14true 3us-gaap_LimitedPartnersCapitalAccountLineItemsus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Limited Partners' Capital Account [Line Items]15false 4us-gaap_LimitedPartnersCapitalAccountUnitsOutstandingus-gaap_truenainstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse93233779323377falsefalsefalse2truefalsefalse93952189395218falsefalsefalsexbrli:sharesItemTypesharesThe number of limited partner units outstanding.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 5 -Subparagraph (SAB TOPIC 4.F) -URI http://asc.fasb.org/extlink&oid=6959260&loc=d3e187171-122770 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 4 -Section F Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 272 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70434-108055 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number 87-21 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Practice Bulletin (PB) -Number 14 -Paragraph 10 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. false1Limited partnership units owned16false 4udr_LimitedPartnersCapitalAccountUnitsOutstandingPercentageudr_falsenainstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truetruefalse0.0510.051falsefalsefalse2truetruefalse0.0510.051falsefalsefalsenum:percentItemTypepureLimited Partners Capital Account Units Outstanding Percentage.No definition available.false0Percentage of units17false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse9false USDtruefalse$D2013Q2YTD_us-gaap_LimitedPartnersCapitalAccountByClassAxis_udr_ClassLimitedPartnerMemberhttp://www.sec.gov/CIK0000074208duration2013-01-01T00:00:002013-06-30T00:00:00falsefalseClass A Limited Partner [Member]us-gaap_LimitedPartnersCapitalAccountByClassAxisxbrldihttp://xbrl.org/2006/xbrldiudr_ClassLimitedPartnerMemberus-gaap_LimitedPartnersCapitalAccountByClassAxisexplicitMembernumberStandardhttp://www.xbrl.org/2003/instancepurexbrli0usd_per_unitDividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.udr.com/20130630Unitsudr0sharesStandardhttp://www.xbrl.org/2003/instancesharesxbrli0USDUSD$nanafalse0Class A Limited Partner [Member]18true 3us-gaap_LimitedPartnersCapitalAccountLineItemsus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Limited Partners' Capital Account [Line Items]19false 4us-gaap_LimitedPartnersCapitalAccountUnitsOutstandingus-gaap_truenainstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2truefalsefalse17516711751671falsefalsefalsexbrli:sharesItemTypesharesThe number of limited partner units outstanding.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 5 -Subparagraph (SAB TOPIC 4.F) -URI http://asc.fasb.org/extlink&oid=6959260&loc=d3e187171-122770 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 4 -Section F Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 272 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70434-108055 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number 87-21 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Practice Bulletin (PB) -Number 14 -Paragraph 10 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. false1Limited partnership units owned20false 4udr_LimitedPartnersCapitalAccountUnitDividendRatePercentageudr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truetruefalse0.080.08falsefalsefalse2falsefalsefalse00falsefalsefalsenum:percentItemTypepureCumulative, annual, non-compounded preferred return percentage of Class A Partnership units.No definition available.false0Cumulative, annual, non-compounded preferred return on Class A Partnership units21false 4udr_LimitedPartnersCapitalAccountUnitValueudr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse16.6116.61falsefalsefalse2falsefalsefalse00falsefalsefalseus-types:perUnitItemTypedecimalValue per Class A Partnership unit which preferred return percentage is based.No definition available.false0Value of Class A Partnership units (in dollars per unit)22false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse11false truefalseI2013Q2_dei_LegalEntityAxis_udr_UnitedDominionRealityLPMember_us-gaap_LimitedPartnersCapitalAccountByClassAxis_udr_ClassLimitedPartnerMemberhttp://www.sec.gov/CIK0000074208instant2013-06-30T00:00:000001-01-01T00:00:00falsefalseClass A Limited Partner [Member]us-gaap_LimitedPartnersCapitalAccountByClassAxisxbrldihttp://xbrl.org/2006/xbrldiudr_ClassLimitedPartnerMemberus-gaap_LimitedPartnersCapitalAccountByClassAxisexplicitMemberfalsefalseUnited Dominion Reality L.P. [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiudr_UnitedDominionRealityLPMemberdei_LegalEntityAxisexplicitMembersharesStandardhttp://www.xbrl.org/2003/instancesharesxbrli0nanafalse0Class A Limited Partner [Member] | United Dominion Reality L.P. [Member]23true 3us-gaap_LimitedPartnersCapitalAccountLineItemsus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Limited Partners' Capital Account [Line Items]24false 4us-gaap_LimitedPartnersCapitalAccountUnitsOutstandingus-gaap_truenainstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse18733321873332falsefalsefalse2truefalsefalse17516711751671falsefalsefalsexbrli:sharesItemTypesharesThe number of limited partner units outstanding.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 5 -Subparagraph (SAB TOPIC 4.F) -URI http://asc.fasb.org/extlink&oid=6959260&loc=d3e187171-122770 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 4 -Section F Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 272 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70434-108055 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number 87-21 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Practice Bulletin (PB) -Number 14 -Paragraph 10 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. false1Limited partnership units owned25false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse13false truefalseI2013Q2_dei_LegalEntityAxis_udr_UdrIncMember_us-gaap_LimitedPartnersCapitalAccountByClassAxis_udr_ClassLimitedPartnerMemberhttp://www.sec.gov/CIK0000074208instant2013-06-30T00:00:000001-01-01T00:00:00falsefalseClass A Limited Partner [Member]us-gaap_LimitedPartnersCapitalAccountByClassAxisxbrldihttp://xbrl.org/2006/xbrldiudr_ClassLimitedPartnerMemberus-gaap_LimitedPartnersCapitalAccountByClassAxisexplicitMemberfalsefalseUDR, Inc. [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiudr_UdrIncMemberdei_LegalEntityAxisexplicitMembersharesStandardhttp://www.xbrl.org/2003/instancesharesxbrli0nanafalse0Class A Limited Partner [Member] | UDR, Inc. [Member]26true 3us-gaap_LimitedPartnersCapitalAccountLineItemsus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Limited Partners' Capital Account [Line Items]27false 4us-gaap_LimitedPartnersCapitalAccountUnitsOutstandingus-gaap_truenainstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse121661121661falsefalsefalse2falsefalsefalse00falsefalsefalsexbrli:sharesItemTypesharesThe number of limited partner units outstanding.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 5 -Subparagraph (SAB TOPIC 4.F) -URI http://asc.fasb.org/extlink&oid=6959260&loc=d3e187171-122770 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 4 -Section F Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 272 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70434-108055 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number 87-21 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Practice Bulletin (PB) -Number 14 -Paragraph 10 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. false1Limited partnership units owned28false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse14false truefalseI2013Q2_dei_LegalEntityAxis_udr_NonAffiliatedPartnersMember_us-gaap_LimitedPartnersCapitalAccountByClassAxis_udr_ClassLimitedPartnerMemberhttp://www.sec.gov/CIK0000074208instant2013-06-30T00:00:000001-01-01T00:00:00falsefalseClass A Limited Partner [Member]us-gaap_LimitedPartnersCapitalAccountByClassAxisxbrldihttp://xbrl.org/2006/xbrldiudr_ClassLimitedPartnerMemberus-gaap_LimitedPartnersCapitalAccountByClassAxisexplicitMemberfalsefalseNon-affiliated Partners [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiudr_NonAffiliatedPartnersMemberdei_LegalEntityAxisexplicitMembersharesStandardhttp://www.xbrl.org/2003/instancesharesxbrli0nanafalse0Class A Limited Partner [Member] | Non-affiliated Partners [Member]29true 3us-gaap_LimitedPartnersCapitalAccountLineItemsus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Limited Partners' Capital Account [Line Items]30false 4us-gaap_LimitedPartnersCapitalAccountUnitsOutstandingus-gaap_truenainstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse17516711751671falsefalsefalse2falsefalsefalse00falsefalsefalsexbrli:sharesItemTypesharesThe number of limited partner units outstanding.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 5 -Subparagraph (SAB TOPIC 4.F) -URI http://asc.fasb.org/extlink&oid=6959260&loc=d3e187171-122770 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 4 -Section F Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 272 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70434-108055 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number 87-21 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Practice Bulletin (PB) -Number 14 -Paragraph 10 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. false1Limited partnership units ownedfalseCapital Structure (UNITED DOMINION REALTY, L.P.) (Details) (USD $)ThousandsNoRoundingUnKnownUnKnowntruefalsefalseSheethttp://www.udr.com/role/CapitalStructureUnitedDominionRealtyLPDetails230