LEASES (UNITED DOMINION REALTY, L.P.) - Lessee Future Minimum Payments - (Details) $ in Thousands	3 Months Ended
Mar. 31, 2020 USD ($) community lease	Dec. 31, 2019 USD ($)
Lessee operating leases
Number of communities subject to ground leases \| community	6
Number of leases \| lease	6
Operating leases existence of option to extend	true
Operating lease right-of-use assets	$ 203,410	$ 204,225
Weighted average remaining lease term	44 years 6 months
Weighted average discount rate	5.00%
Number of real estate properties \| community	150
Future minimum lease payments
Operating lease liabilities	$ 197,829	198,558
Ground Leases
Future minimum lease payments
2020	9,330
2021	12,442
2022	12,442
2023	12,442
2024	12,442
Thereafter	455,221
Total future minimum lease payments (undiscounted)	514,319
Difference between future undiscounted cash flows and discounted cash flows	(316,490)
Operating lease liabilities	$ 197,829
United Dominion Realty L.P.
Lessee operating leases
Number of communities subject to ground leases \| community	6
Operating leases existence of option to extend	true
Operating lease right-of-use assets	$ 204,723	205,668
Weighted average remaining lease term	44 years 6 months
Weighted average discount rate	5.00%
Number of real estate properties \| community	52
Future minimum lease payments
2020	$ 9,438
2021	12,589
2022	12,592
2023	12,595
2024	12,598
Thereafter	456,016
Total future minimum lease payments (undiscounted)	515,828
Difference between future undiscounted cash flows and discounted cash flows	(316,679)
Operating lease liabilities	199,149	$ 200,001
United Dominion Realty L.P. \| Ground Leases
Future minimum lease payments
2020	9,330
2021	12,442
2022	12,442
2023	12,442
2024	12,442
Thereafter	455,221
Total future minimum lease payments (undiscounted)	514,319
Difference between future undiscounted cash flows and discounted cash flows	(316,490)
Operating lease liabilities	197,829
United Dominion Realty L.P. \| Equipment Leases
Future minimum lease payments
2020	108
2021	147
2022	150
2023	153
2024	156
Thereafter	795
Total future minimum lease payments (undiscounted)	1,509
Difference between future undiscounted cash flows and discounted cash flows	(189)
Operating lease liabilities	$ 1,320

The number of communities that are subject to ground leases that the Company is the lessee.

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Number of leases.

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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.

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- Definition

Indicates (true false) whether lessee has option to extend operating lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=77888426&loc=SL77918673-209980

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- Definition

Amount of lessee's undiscounted obligation for lease payments for operating lease.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=77888426&loc=SL77918701-209980

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- Definition

Amount of lessee's undiscounted obligation for lease payments for operating lease, due after fifth fiscal year following latest fiscal year.

+ References

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Amount of lessee's undiscounted obligation for lease payments for operating lease, due in fifth fiscal year following latest fiscal year.

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Amount of lessee's undiscounted obligation for lease payments for operating lease, due in fourth fiscal year following latest fiscal year.

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Amount of lessee's undiscounted obligation for lease payments for operating lease, due in third fiscal year following latest fiscal year.

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Amount of lessee's undiscounted obligation for lease payments for operating lease, due in second fiscal year following latest fiscal year.

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- Definition

Amount of lessee's undiscounted obligation for lease payments for operating lease having an initial or remaining lease term in excess of one year due in remainder of fiscal year following latest fiscal year.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=77888426&loc=SL77918701-209980

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Amount of lessee's undiscounted obligation for lease payments in excess of discounted obligation for lease payments for operating lease.

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- Definition

The number of real estate properties owned as of the balance sheet date.

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Present value of lessee's discounted obligation for lease payments from operating lease.

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-Publisher FASB
-Name Accounting Standards Codification
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- Definition

Amount of lessee's right to use underlying asset under operating lease.

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- Definition

Weighted average discount rate for operating lease calculated at point in time.

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- Definition

Weighted average remaining lease term for operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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