Organization and Basis of Presentation - Narrative (Details) ft² in Millions, $ in Billions	9 Months Ended
	Sep. 30, 2023 USD ($) ft² property building item
Real estate properties
Number of Real Estate Properties	48
Number of key demand drivers | item	4
National Landing Sub-market, Northern Virginia
Real estate properties
Percentage of operating portfolio by the entity	66.67%
Future Development
Real estate properties
Number of Real Estate Properties	20
Area of real estate property | ft²	12.5
Commercial Real Estate
Real estate properties
Number of Real Estate Properties	30
Area of real estate property | ft²	9.2
One Commercial Building
Real estate properties
Number of Real Estate Properties | building	1
Subordinated interest	10.00%
Four Commercial Buildings
Real estate properties
Number of Real Estate Properties | building	4
Subordinated interest	33.50%
Three Commercial Buildings
Real estate properties
Number of Real Estate Properties | building	3
Subordinated interest	49.00%
Multifamily
Real estate properties
Number of Real Estate Properties	16
Number of Units in Real Estate Property | item	6,318
Multifamily | Asset under Construction
Real estate properties
Number of Real Estate Properties	2
Number of Units in Real Estate Property | item	1,583
Wholly Owned Properties
Real estate properties
Number of properties for ground lease	2
Wholly Owned Properties | Future Development
Real estate properties
Area of real estate property | ft²	9.8
Wholly Owned Properties | Commercial Real Estate
Real estate properties
Area of real estate property | ft²	8.1
Wholly Owned Properties | Multifamily
Real estate properties
Number of Units in Real Estate Property | item	6,318
Wholly Owned Properties | Multifamily | Asset under Construction
Real estate properties
Number of Units in Real Estate Property | item	1,583
Virginia Tech
Real estate properties
Under-construction property value developed by Virginia Tech | $	$ 1
JBG Smith, LP
Real estate properties
Ownership interest by parent	87.70%