Percentage of Outstanding Common Shares Distributed

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- Definition

Area of a real estate property.

+ References

No definition available.

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- Definition

Number of shares of equity interests issued or issuable to acquire entity.

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-Name Accounting Standards Codification
-Topic 805
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- Definition

Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury.

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-Section S99
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- Definition

Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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- Definition

Other operating costs incurred during the reporting period and may include amounts paid to maintain the property.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
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- Definition

The number of limited partner units issued.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
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- Definition

The number of limited partner units outstanding.

+ References

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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

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

+ References

No definition available.

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- Definition

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

+ References

No definition available.

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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.

+ References

No definition available.

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Organization and Basis of Presentation - Narrative (Details) shares in Thousands, $ in Thousands			12 Months Ended
	Jul. 18, 2017 ft² building_unit properties shares	Jul. 17, 2017 shares	Dec. 31, 2018 USD ($) ft² building_unit properties shares	Dec. 31, 2017 USD ($) shares	Dec. 31, 2016 USD ($)
Real Estate Properties [Line Items]
Common Stock, Shares, Issued \| shares		94,700	120,937	117,955
Limited Partners' Capital Account, Units Issued \| shares		5,800
Outstanding common shares and common limited partnership units prior to the Combination \| shares	118,000		120,937	117,955
Limited Partners' Capital Account, Units Outstanding \| shares	19,800
Number of Real Estate Properties			62
Cost of Other Property Operating Expense \| $			$ 148,081	$ 118,836	$ 100,304
Asset under Construction
Real Estate Properties [Line Items]
Number of Real Estate Properties			9
Future Development
Real Estate Properties [Line Items]
Number of Real Estate Properties			41
Area of real estate property (in square feet) \| ft²			23,100,000
Commercial Real Estate [Member]
Real Estate Properties [Line Items]
Number of Real Estate Properties			46
Area of real estate property (in square feet) \| ft²			12,900,000
Commercial Real Estate [Member] \| Asset under Construction
Real Estate Properties [Line Items]
Number of Real Estate Properties			5
Area of real estate property (in square feet) \| ft²			1,200,000
Multifamily
Real Estate Properties [Line Items]
Number of Real Estate Properties			16
Number of Units in Real Estate Property \| building_unit			6,315
Multifamily \| Asset under Construction
Real Estate Properties [Line Items]
Number of Real Estate Properties			4
Number of Units in Real Estate Property \| building_unit			1,476
Wholly Owned Properties \| Future Development
Real Estate Properties [Line Items]
Area of real estate property (in square feet) \| ft²			19,600,000
Wholly Owned Properties \| Commercial Real Estate [Member]
Real Estate Properties [Line Items]
Area of real estate property (in square feet) \| ft²			11,300,000
Wholly Owned Properties \| Commercial Real Estate [Member] \| Asset under Construction
Real Estate Properties [Line Items]
Area of real estate property (in square feet) \| ft²			927,000
Wholly Owned Properties \| Multifamily
Real Estate Properties [Line Items]
Number of Units in Real Estate Property \| building_unit			4,531
Wholly Owned Properties \| Multifamily \| Asset under Construction
Real Estate Properties [Line Items]
Area of real estate property (in square feet) \| ft²			1,298
JBG Smith, LP
Real Estate Properties [Line Items]
Ownership interest by parent			87.80%
JBG Companies
Real Estate Properties [Line Items]
Common shares and OP Units issued in consideration \| shares	37,164
Outstanding common shares and common limited partnership units prior to the Combination \| shares		100,571
Number of Real Estate Properties	30
JBG Companies \| Commercial Real Estate [Member]
Real Estate Properties [Line Items]
Number of Real Estate Properties	21
Area of real estate property (in square feet) \| ft²	4,100,000
JBG Companies \| Multifamily
Real Estate Properties [Line Items]
Number of Real Estate Properties	9
Number of Units in Real Estate Property \| building_unit	2,883
JBG Companies \| Wholly Owned Properties \| Commercial Real Estate [Member]
Real Estate Properties [Line Items]
Area of real estate property (in square feet) \| ft²	2,400,000
JBG Companies \| Wholly Owned Properties \| Multifamily
Real Estate Properties [Line Items]
Number of Units in Real Estate Property \| building_unit	1,099
JBG Companies \| Common Shares
Real Estate Properties [Line Items]
Common shares and OP Units issued in consideration \| shares	23,200
JBG Companies \| Partnership Interest [Member]
Real Estate Properties [Line Items]
Common shares and OP Units issued in consideration \| shares	13,900
Affiliated Entity [Member] \| Vornado Realty Trust [Member]
Real Estate Properties [Line Items]
Percentage of Outstanding Common Shares Distributed		100.00%
Restatement Adjustment [Member]
Real Estate Properties [Line Items]
Cost of Other Property Operating Expense \| $				$ 7,800