XML 79 R95.htm IDEA: XBRL DOCUMENT
v3.20.1

SIGNIFICANT ACCOUNTING POLICIES (UNITED DOMINION REALTY, L.P.) (Details) - USD ($) $ in Thousands | 3 Months Ended |
--- | --- | ---
Mar. 31, 2020 | Mar. 31, 2019 | Dec. 31, 2019
Accounting policies |  |  |
Operating lease right-of-use assets | $ 203,410 |  | $ 204,225
Operating lease liabilities | 197,829 |  | 198,558
Development costs excluding direct costs and capitalized interest | 6,900 | $ 3,300 |
Interest capitalized during period | 1,400 | 1,100 |
United Dominion Realty L.P. |  |  |
Accounting policies |  |  |
Operating lease right-of-use assets | 204,723 |  | 205,668
Operating lease liabilities | 199,149 |  | $ 200,001
Development costs excluding direct costs and capitalized interest | 400 |  |
Unrecognized Tax Benefits | 0 |  |
United Dominion Realty L.P. | Maximum |  |  |
Accounting policies |  |  |
Development costs excluding direct costs and capitalized interest |  | 100 |
Interest capitalized during period | $ 100 | $ 100 |

X
- Definition Accounting Policies [Line Items] + References No definition available. + Details
Name: | udr_AccountingPoliciesLineItems
Namespace Prefix: | udr_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Development Costs Excluding Direct Costs and Capitalized Interest + References No definition available. + Details
Name: | udr_DevelopmentCostsExcludingDirectCostsAndCapitalizedInterest
Namespace Prefix: | udr_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of interest capitalized, including amount of allowance for funds used during construction. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 980 -SubTopic 835 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6501662&loc=d3e56162-110433 + Details
Name: | us-gaap_InterestCostsIncurredCapitalized
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Present value of lessee's discounted obligation for lease payments from operating lease. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 842 -SubTopic 20 -Section 45 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=77888419&loc=SL77918627-209977 + Details
Name: | us-gaap_OperatingLeaseLiability
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of lessee's right to use underlying asset under operating lease. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 842 -SubTopic 20 -Section 45 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=77888419&loc=SL77918627-209977 + Details
Name: | us-gaap_OperatingLeaseRightOfUseAsset
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of unrecognized tax benefits. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 45 -Paragraph 10B -URI http://asc.fasb.org/extlink&oid=116821951&loc=SL37586934-109318 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 15A -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=84230637&loc=SL6600010-109319 + Details
Name: | us-gaap_UnrecognizedTaxBenefits
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | dei_LegalEntityAxis=udr_UnitedDominionRealityLPMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |