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v3.19.3.a.u2

Redeemable Noncontrolling Interests - Narrative (Details) - shares | 2 Months Ended | 12 Months Ended
--- | --- | ---
Feb. 20, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Noncontrolling Interest [Line Items] |  |  |
Conversion of common limited partnership units to common shares |  |  | 2,962,000
Consolidated Real Estate Venture |  |  |
Noncontrolling Interest [Line Items] |  |  |
Ownership interest by parent |  | 95.00% |
Ownership interest by parent, threshold for capital contributions to cease |  | 97.00% |
OP Units [Member] |  |  |
Noncontrolling Interest [Line Items] |  |  |
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares |  | 15,200,000 |
Conversion of common limited partnership units to common shares |  | 1,700,000 | 3,000,000.0
OP Units [Member] | JBG Smith, LP |  |  |
Noncontrolling Interest [Line Items] |  |  |
Ownership interest by parent |  | 10.10% |
Minimum |  |  |
Noncontrolling Interest [Line Items] |  |  |
Redemption period |  | 2 years |
Maximum |  |  |
Noncontrolling Interest [Line Items] |  |  |
Redemption period |  | 7 years |
Subsequent Event [Member] | OP Units [Member] |  |  |
Noncontrolling Interest [Line Items] |  |  |
Conversion of common limited partnership units to common shares | 733,851 |  |

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