Organization and Basis of Presentation - Narrative (Details) ft² in Millions, $ in Billions	Mar. 31, 2022 USD ($) ft² property item
Real Estate Properties [Line Items]
Number of Real Estate Properties \| property	62
Near-Term Development
Real Estate Properties [Line Items]
Number of Real Estate Properties \| property	9
Area of real estate property \| ft²	4.1
Future Development
Real Estate Properties [Line Items]
Number of Real Estate Properties \| property	20
Area of real estate property \| ft²	13.0
Commercial Real Estate
Real Estate Properties [Line Items]
Number of Real Estate Properties \| property	41
Area of real estate property \| ft²	13.0
Multifamily
Real Estate Properties [Line Items]
Number of Real Estate Properties \| property	20
Number of Units in Real Estate Property \| item	7,715
Multifamily \| Asset under Construction
Real Estate Properties [Line Items]
Number of Real Estate Properties \| property	2
Number of Units in Real Estate Property \| item	1,583
Wholly Owned Properties
Real Estate Properties [Line Items]
Number of properties for ground lease \| property	1
Wholly Owned Properties \| Near-Term Development
Real Estate Properties [Line Items]
Area of real estate property \| ft²	3.9
Wholly Owned Properties \| Future Development
Real Estate Properties [Line Items]
Area of real estate property \| ft²	10.5
Wholly Owned Properties \| Commercial Real Estate
Real Estate Properties [Line Items]
Area of real estate property \| ft²	11.3
Wholly Owned Properties \| Multifamily
Real Estate Properties [Line Items]
Number of Units in Real Estate Property \| item	6,502
Wholly Owned Properties \| Multifamily \| Asset under Construction
Real Estate Properties [Line Items]
Number of Units in Real Estate Property \| item	1,583
Amazon \| Near-Term Development
Real Estate Properties [Line Items]
Area of real estate property \| ft²	5.0
Virginia Tech
Real Estate Properties [Line Items]
Under-construction property value developed by Virginia Tech \| $	$ 1
JBG Smith, LP
Real Estate Properties [Line Items]
Ownership interest by parent	89.00%

Value of real estate property being developed by Virginia Tech.

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- Definition

Area of a real estate property.

+ References

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- Definition

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

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- Definition

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

+ References

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- Definition

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

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- Definition

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

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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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