Schedule III - Real Estate and Accumulated Depreciation-Encumbrances Reconciliation (Details)	Dec. 31, 2018 USD ($) Property
Total Consolidated Investment in Real Estate [Member]
Overall summary of real estate and accumulated depreciation
Encumbrances	$ 2,385,470,484
Archstone Master Property [Member]
Real Estate and Accumulated Depreciation Encumbrances Reconciliation [Abstract]
Number of Properties Encumbered \| Property	13
Overall summary of real estate and accumulated depreciation
Encumbrances	$ 797,768,476
Portfolio Entity Encumbrances [Member]
Real Estate and Accumulated Depreciation Encumbrances Reconciliation [Abstract]
Number of Properties Encumbered \| Property	13
Portfolio Entity Encumbrances [Member]
Overall summary of real estate and accumulated depreciation
Encumbrances	$ 797,768,476
Individual Property Encumbrances [Member]
Overall summary of real estate and accumulated depreciation
Encumbrances	$ 1,587,702,008

Represents the number of rental properties encumbered by a lien or mortgage.

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- Definition

Overall summary of real estate and accumulated depreciation.

+ References

No definition available.

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- Definition

Real estate and accumulated depreciation encumbrances reconciliation.

+ References

No definition available.

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- Definition

Amount of lien or mortgage outstanding on real estate investment properties for entities with a substantial portion of business acquiring and holding investment real estate.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 12
-Paragraph Column B
-Subsection 28

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 970
-SubTopic 360
-Section S99
-Paragraph 1
-Subparagraph (SX 210.12-28(Column B))
-URI http://asc.fasb.org/extlink&oid=6590653&loc=d3e638233-123024

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