Area owned by Real estate venture of undeveloped parcels of land (in acres).

No definition available.

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Period Type:	instant

- Definition

Area of a real estate property.

+ References

No definition available.

+ Details

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- Definition

Amount of unused borrowing capacity under the long-term financing arrangement that is available to the entity as of the balance sheet date.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(b))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

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- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571

+ Details

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Balance Type:	na
Period Type:	instant

- Definition

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

+ References

No definition available.

+ Details

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Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

The cash outflow associated with the purchase of or advances to an equity method investments, which are investments in joint ventures and entities in which the entity has an equity ownership interest normally of 20 to 50 percent and exercises significant influence.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3213-108585

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The cash outflow associated with the investment in or advances to an entity in which the reporting entity shares control of the entity with another party or group.

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- 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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- Details

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Balance Type:
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- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES - 4040 Wilson Venture (Details) $ in Thousands		12 Months Ended
	Jul. 31, 2013 USD ($) a ft² property	Dec. 31, 2020 USD ($) ft² property	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Schedule of Equity Method Investments [Line Items]
Area of real estate property \| ft²		13,852,464
Number of properties \| property		82
Cash paid to acquire real estate ventures		$ 0	$ 2,181	$ 0
Advanced under the construction loan		$ 719	$ 253	$ 908
4040 Wilson Venture
Schedule of Equity Method Investments [Line Items]
Ownership percentage	50.00%	50.00%
Area owned by real estate venture of undeveloped parcels of land \| a	1.3
Secured construction loan with total borrowing capacity					$ 150,000
Advanced under the construction loan		$ 141,900
Mixed Use Property \| 4040 Wilson Venture
Schedule of Equity Method Investments [Line Items]
Area of real estate property \| ft²	427,500
Number of properties \| property	8
Brandywine Realty Trust
Schedule of Equity Method Investments [Line Items]
Ownership percentage		50.00%
Brandywine Realty Trust \| 4040 Wilson Venture
Schedule of Equity Method Investments [Line Items]
Cash paid to acquire real estate ventures	$ 36,000