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Income/(Loss) Per Share Income/(Loss) Per Share (Details) - shares | 12 Months Ended
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Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] |  |  |
Weighted Average Number Diluted Shares Outstanding Adjustment | 0 |  |
Partners' Capital Account, Units | 183,278,698 | 183,278,698 |
OP Units |  |  |
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] |  |  |
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount | 12,947,000 | 9,247,000 | 9,337,000
Convertible Preferred Stock [Member] |  |  |
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] |  |  |
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount | 3,032,000 | 3,036,000 | 3,036,000
Stock Compensation Plan [Member] |  |  |
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] |  |  |
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount | 2,051,000 | 1,917,000 | 1,584,000
UDR Lighthouse DownREIT L.P. [Member] |  |  |
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] |  |  |
Partners' Capital Account, Units | 32,367,380 |  |
UDR Lighthouse DownREIT L.P. [Member] | General Partner [Member] |  |  |
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] |  |  |
Partners' Capital Account, Units | 16,229,407 | 0 | 0

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- Definition Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Antidilution -URI http://asc.fasb.org/extlink&oid=6505113 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Diluted Earnings Per Share -URI http://asc.fasb.org/extlink&oid=6510752 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Contingent Stock Agreement -URI http://asc.fasb.org/extlink&oid=6508534 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257 + Details
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
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- Definition The 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. + References 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(b)) -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 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 3: 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=27012166&loc=d3e187171-122770 Reference 4: 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 + Details
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