Organization and Basis of Presentation (Details) ft² in Millions	Jun. 30, 2026 ft² building item property
Organization and Basis of Presentation
Number of real estate properties	38
National Landing
Organization and Basis of Presentation
Percentage of operating portfolio by the entity	77.00%
Future Development
Organization and Basis of Presentation
Area of real estate property \| ft²	4.8
Multifamily
Organization and Basis of Presentation
Number of real estate properties	15
Number of units in real estate property \| item	6,519
Number of real estate properties under construction	1
Number of units in an under construction real estate property \| item	195
Commercial Real Estate
Organization and Basis of Presentation
Number of real estate properties	22
Area of real estate property \| ft²	7.3
Four Commercial Buildings
Organization and Basis of Presentation
Subordinated interest	33.50%
Number of real estate properties \| building	4
Wholly Owned Properties
Organization and Basis of Presentation
Number of properties for ground lease	1
Wholly Owned Properties \| Future Development
Organization and Basis of Presentation
Area of real estate property \| ft²	3.5
Wholly Owned Properties \| Multifamily
Organization and Basis of Presentation
Number of units in real estate property \| item	6,333
Number of units in an under construction real estate property \| item	59
Wholly Owned Properties \| Commercial Real Estate
Organization and Basis of Presentation
Area of real estate property \| ft²	6.7
JBG Smith, LP
Organization and Basis of Presentation
Ownership interest by parent	81.80%

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

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The number of units in an under construction real estate property owned as of the balance sheet date.

+ References

No definition available.

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Percentage of operating portfolio in which the entity serves as the developer.

+ References

No definition available.

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- Definition

Percentage of subordinated interest held through an unconsolidated real estate venture.

+ References

No definition available.

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- Definition

Area of a real estate property.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 275
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482861/275-10-50-2

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 970
-SubTopic 360
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.12-28(Column A)(Footnote 2))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478979/970-360-S99-1

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 970
-SubTopic 360
-Name Accounting Standards Codification
-Section 30
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478150/970-360-30-2

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- Definition

The parent entity's interest in net assets of the subsidiary, expressed as a percentage.

+ References

No definition available.

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- Definition

Number of separate real estate development properties located on land subject to ground leases.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 842
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478964/842-20-50-3

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

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The number of units in a real estate property owned as of the balance sheet date.

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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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