Investments in Partially Owned Entities - Other - Additional Information (Details) - USD ($)	Mar. 31, 2018	Dec. 31, 2017
Variable Interest Entity [Line Items]
Investments in unconsolidated entities	$ 59,091,000	$ 58,254,000
Unconsolidated Non-VIE
Variable Interest Entity [Line Items]
Investments in unconsolidated entities	0
Unconsolidated Non-VIE \| Residual JV [Member]
Variable Interest Entity [Line Items]
Investments in unconsolidated entities	$ 800,000
Joint venture ownership percentage owned by company	60.00%
Joint venture partner ownership percentage	40.00%
Unconsolidated Non-VIE \| Legacy JV [Member]
Variable Interest Entity [Line Items]
Joint venture ownership percentage owned by company	60.00%
Joint venture partner ownership percentage	40.00%
Liquidation Value Preferred Interests	$ 37,300,000
Private Equity Fund \| Capital Commitment
Variable Interest Entity [Line Items]
Investments in unconsolidated entities	4,100,000
Private Equity Fund \| Maximum [Member]
Variable Interest Entity [Line Items]
Investments in unconsolidated entities	$ 5,000,000

Joint venture ownership interest percentage owned by coventurer.

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- Definition

Joint venture ownership interest percentage owned by company.

+ References

No definition available.

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- Definition

The aggregate liquidation preference of preferred interests acquired in conjunction with the Archstone transaction.

+ References

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- Definition

Total investments in (A) an entity in which the entity has significant influence, but does not have control, (B) subsidiaries that are not required to be consolidated and are accounted for using the equity and or cost method, and (C) an entity in which the reporting entity shares control of the entity with another party or group. Includes long-term advances receivable from a party that is affiliated with the reporting entity by means of direct or indirect ownership.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.12)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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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.

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