2.4.0.82402401 - Disclosure - Consolidation and Basis of Presentation (UNITED DOMINION REALTY, L.P.) (Details)truefalsefalse1false falsefalseD2013Q2_dei_LegalEntityAxis_udr_UnitedDominionRealityLPMemberhttp://www.sec.gov/CIK0000074208duration2013-04-01T00:00:002013-06-30T00:00:00numberStandardhttp://www.xbrl.org/2003/instancepurexbrli0sharesStandardhttp://www.xbrl.org/2003/instancesharesxbrli0MarketsStandardhttp://www.udr.com/20130630Marketsudr0Apartment_HomesStandardhttp://www.udr.com/20130630Apartment_Homesudr0CommunitiesStandardhttp://www.udr.com/20130630Communitiesudr02false falsefalseD2012Q2_dei_LegalEntityAxis_udr_UnitedDominionRealityLPMemberhttp://www.sec.gov/CIK0000074208duration2012-04-01T00:00:002012-06-30T00:00:00numberStandardhttp://www.xbrl.org/2003/instancepurexbrli03false falsefalseD2013Q2YTD_dei_LegalEntityAxis_udr_UnitedDominionRealityLPMemberhttp://www.sec.gov/CIK0000074208duration2013-01-01T00:00:002013-06-30T00:00:00numberStandardhttp://www.xbrl.org/2003/instancepurexbrli0sharesStandardhttp://www.xbrl.org/2003/instancesharesxbrli0MarketsStandardhttp://www.udr.com/20130630Marketsudr0Apartment_HomesStandardhttp://www.udr.com/20130630Apartment_Homesudr0CommunitiesStandardhttp://www.udr.com/20130630Communitiesudr04false falsefalseD2012Q2YTD_dei_LegalEntityAxis_udr_UnitedDominionRealityLPMemberhttp://www.sec.gov/CIK0000074208duration2012-01-01T00:00:002012-06-30T00:00:00numberStandardhttp://www.xbrl.org/2003/instancepurexbrli05false falsefalseI2012Q4_dei_LegalEntityAxis_udr_UnitedDominionRealityLPMemberhttp://www.sec.gov/CIK0000074208instant2012-12-31T00:00:000001-01-01T00:00:00sharesStandardhttp://www.xbrl.org/2003/instancesharesxbrli01true 3dei_EntityInformationLineItemsdei_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Entity Information [Line Items]2false 4udr_NumberOfOwnedAndConsolidatedCommunityudr_falsenainstantfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1truefalsefalse141141falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse141141falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsexbrli:integerItemTypeintegerNumber Of Owned And Consolidated CommunityNo definition available.false256Number of communities owned (in communities)3false 4udr_NumberOfApartmentHomesOwnedAndConsolidatedByCompanyudr_falsenainstantfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1truefalsefalse4115341153falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse4115341153falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsexbrli:integerItemTypeintegerNumber Of Apartment Homes Owned And Consolidated By CompanyNo definition available.false256Number of apartments owned (in apartments homes)4false 4us-gaap_PartnersCapitalAccountUnitsus-gaap_truenainstantfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1truefalsefalse184281253184281253falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse184281253184281253falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsexbrli:sharesItemTypesharesThe number of each class of partnership units outstanding at the balance sheet date. Units represent shares of ownership of the general, limited, and preferred partners.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 946 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.6-04.16(a)) -URI http://asc.fasb.org/extlink&oid=6488278&loc=d3e603758-122996 Reference 2: 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 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 15 -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 SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Paragraph 16 -Subparagraph a, b -Article 6 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 946 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.6-04.16(b)) -URI http://asc.fasb.org/extlink&oid=6488278&loc=d3e603758-122996 false1Operating Partnership outstanding units5false 4us-gaap_GeneralPartnersCapitalAccountUnitsOutstandingus-gaap_truenainstantfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1truefalsefalse174957876174957876falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse174957876174957876falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsexbrli: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. false1OP units outstanding related to general partner6false 4udr_GeneralPartnersCapitalAccountUnitsOwnedPercentageudr_falsenainstantfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1truetruefalse0.9490.949falsefalsefalse2falsefalsefalse00falsefalsefalse3truetruefalse0.9490.949falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsenum:percentItemTypepureGeneral Partners Capital Account Units Owned Percentage.No definition available.false0Percentage of units owned by UDR7false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalse2false truefalseD2013Q2_dei_LegalEntityAxis_udr_UnitedDominionRealityLPMemberhttp://www.sec.gov/CIK0000074208duration2013-04-01T00:00:002013-06-30T00:00:00falsefalseUnited Dominion Reality L.P. [Member]dei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldiudr_UnitedDominionRealityLPMemberdei_LegalEntityAxisexplicitMembernumberStandardhttp://www.xbrl.org/2003/instancepurexbrli0sharesStandardhttp://www.xbrl.org/2003/instancesharesxbrli0MarketsStandardhttp://www.udr.com/20130630Marketsudr0Apartment_HomesStandardhttp://www.udr.com/20130630Apartment_Homesudr0CommunitiesStandardhttp://www.udr.com/20130630Communitiesudr0nanafalse0United Dominion Reality L.P. [Member]8true 3dei_EntityInformationLineItemsdei_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Entity Information [Line Items]9false 4udr_RentalRevenuesPercentOfParentRentalRevenueudr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truetruefalse0.540.54falsefalsefalse2truetruefalse0.530.53falsefalsefalse3truetruefalse0.540.54falsefalsefalse4truetruefalse0.530.53falsefalsefalse5falsefalsefalse00falsefalsefalsenum:percentItemTypepureRental Revenues, Percent of Parent RevenueNo definition available.false0Rental revenues percent of General Partner's consolidated rental revenues10false 4udr_NumberOfOwnedAndConsolidatedCommunityudr_falsenainstantfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1truefalsefalse7070falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse7070falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsexbrli:integerItemTypeintegerNumber Of Owned And Consolidated CommunityNo definition available.false256Number of communities owned (in communities)11false 4udr_NumberOfMarketsOperatingWithinudr_falsenainstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse1818falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse1818falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsexbrli:integerItemTypeintegerNumber of Markets Operating WithinNo definition available.false256Number of markets operating within (in markets)12false 4udr_NumberOfApartmentHomesOwnedAndConsolidatedByCompanyudr_falsenainstantfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1truefalsefalse2166021660falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse2166021660falsefalsefalse4falsefalsefalse00falsefalsefalse5falsefalsefalse00falsefalsefalsexbrli:integerItemTypeintegerNumber Of Apartment Homes Owned And Consolidated By CompanyNo definition available.false256Number of apartments owned (in apartments homes)13false 4us-gaap_GeneralPartnersCapitalAccountUnitsOutstandingus-gaap_truenainstantfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1truefalsefalse110883110883falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse110883110883falsefalsefalse4falsefalsefalse00falsefalsefalse5truefalsefalse110883110883falsefalsefalsexbrli: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. false1OP units outstanding related to general partner14false 4us-gaap_LimitedPartnersCapitalAccountUnitsOutstandingus-gaap_truenainstantfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1truefalsefalse184170370184170370falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse184170370184170370falsefalsefalse4falsefalsefalse00falsefalsefalse5truefalsefalse184170370184170370falsefalsefalsexbrli: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. false1OP units outstanding related to limited partnerfalseConsolidation and Basis of Presentation (UNITED DOMINION REALTY, L.P.) (Details)UnKnownNoRoundingUnKnownUnKnowntruefalsefalseSheethttp://www.udr.com/role/ConsolidationAndBasisOfPresentationUnitedDominionRealtyLPDetails514