Redeemable Noncontrolling Interests - Summary of the Activity of Redeemable Noncontrolling Interests (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Temporary Equity
Beginning Balance	$ 609,129	$ 0
Fair value of OP Unit redemptions	(109,208)	0	$ 0
Issuance of common limited partnership units at the Separation	0	96,632	0
OP Units issued in connection with the Combination (1)	0	359,967
Net income (loss) attributable to redeemable noncontrolling interests	6,710	(7,328)
Other comprehensive income	1,384	225
Contributions (distributions)	(18,237)	(3,693)
Share-based compensation expense	52,190	32,634
Adjustment to redemption value	16,172	130,692
Ending Balance	558,140	609,129	0
Business Combination, Contingent Consideration, Liability	110,600
JBG Smith, LP
Temporary Equity
Beginning Balance	603,717	0
Fair value of OP Unit redemptions	(109,208)	0
Issuance of common limited partnership units at the Separation	0	96,632
OP Units issued in connection with the Combination (1)	0	359,967
Net income (loss) attributable to redeemable noncontrolling interests	6,641	(7,320)
Other comprehensive income	1,384	225
Contributions (distributions)	(18,737)	(9,113)
Share-based compensation expense	52,190	32,634
Adjustment to redemption value	16,172	130,692
Ending Balance	552,159	603,717	0
Consolidated Real Estate Venture
Temporary Equity
Beginning Balance	5,412	0
Fair value of OP Unit redemptions	0	0
Issuance of common limited partnership units at the Separation	0	0
OP Units issued in connection with the Combination (1)	0	0
Net income (loss) attributable to redeemable noncontrolling interests	69	(8)
Other comprehensive income	0	0
Contributions (distributions)	500	5,420
Share-based compensation expense	0	0
Adjustment to redemption value	0	0
Ending Balance	$ 5,981	$ 5,412	$ 0

Temporary Equity, Contributions (Distributions)

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Temporary Equity, Other Comprehensive Income (Loss)

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Temporary Equity, Redemptions of OP Units

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Temporary Equity, Share-based Compensation

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Temporary Equity, Stock Issued During Period, Value, Acquisitions

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- Definition

Amount of liability recognized arising from contingent consideration in a business combination.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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As of the reporting date, the aggregate carrying amount of all noncontrolling interests which are redeemable by the (parent) entity (1) at a fixed or determinable price on a fixed or determinable date, (2) at the option of the holder of the noncontrolling interest, or (3) upon occurrence of an event that is not solely within the control of the (parent) entity. This item includes noncontrolling interest holder's ownership (or holders' ownership) regardless of the type of equity interest (common, preferred, other) including all potential organizational (legal) forms of the investee entity.

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-Publisher FASB
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Change in the value of each type or class of stock classified as temporary equity during the period. The redemption requirement does not constitute an unconditional obligation that will be settled in a variable number of shares constituting a monetary value predominantly indexed to (a) a fixed monetary amount known at inception, (b) an amount inversely correlated with the residual value of the entity, or (c) an amount determined by reference to something other than the fair value of issuer's stock. Does not include mandatorily redeemable stock. The exception is if redemption is required upon liquidation or termination of the reporting entity.

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- Definition

The portion of net income or loss attributable to temporary equity interest.

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Value of new stock classified as temporary equity issued during the period.

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