Commitments and Contingencies	6 Months Ended
Jun. 30, 2020
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	17.Commitments and Contingencies Insurance We maintain general liability insurance with limits of $150.0 million per occurrence and in the aggregate, and property and rental value insurance coverage with limits of $1.5 billion per occurrence, with sub-limits for certain perils such as floods and earthquakes on each of our properties. We also maintain coverage, through our wholly owned captive insurance subsidiary, for a portion of the first loss on the above limits and for both terrorist acts and for nuclear, biological, chemical or radiological terrorism events with limits of $2.0 billion per occurrence. These policies are partially reinsured by third-party insurance providers. We will continue to monitor the state of the insurance market and the scope and costs of coverage for acts of terrorism. We cannot anticipate what coverage will be available on commercially reasonable terms in the future. We are responsible for deductibles and losses in excess of the insurance coverage, which could be material. Our debt, consisting of mortgages payable secured by our properties, a revolving credit facility and unsecured term loans, contains customary covenants requiring adequate insurance coverage. Although we believe that we currently have adequate insurance coverage, we may not be able to obtain an equivalent amount of coverage at reasonable costs in the future. If lenders insist on greater coverage than we are able to obtain, it could adversely affect the ability to finance or refinance our properties. Construction Commitments As of June 30, 2020, we had construction in progress that will require an additional $52.6 million to complete ($35.3 million related to our consolidated entities and $17.3 million related to our unconsolidated real estate ventures at our share), based on our current plans and estimates, which we anticipate will be primarily expended over the next one to two years. These capital expenditures are generally due as the work is performed, and we expect to finance them with debt proceeds, proceeds from asset recapitalizations and sales, issuance and sale of equity securities and available cash. Environmental Matters Most of our assets have been subject, at some point, to environmental assessments that are intended to evaluate the environmental condition of the subject and surrounding assets. The environmental assessments did not reveal any material environmental contamination that we believe would have a material adverse effect on our overall business, financial condition or results of operations, or that have not been anticipated and remediated during site redevelopment as required by law. Nevertheless, there can be no assurance that the identification of new areas of contamination, changes in the extent or known scope of contamination, the discovery of additional sites or changes in cleanup requirements would not result in significant cost to us. Environmental liabilities totaled $17.9 million as of both June 30, 2020 and December 31, 2019 and are included in "Other liabilities, net" in our balance sheets. Other There are various legal actions against us in the ordinary course of business. In our opinion, the outcome of such matters will not have a material adverse effect on our financial condition, results of operations or cash flows. From time to time, we (or ventures in which we have an ownership interest) have agreed, and may in the future agree with respect to unconsolidated real estate ventures, to (1) guarantee portions of the principal, interest and other amounts in connection with borrowings, (2) provide customary environmental indemnifications and nonrecourse carve-outs (e.g., guarantees against fraud, misrepresentation and bankruptcy) in connection with borrowings or (3) provide guarantees to lenders and other third parties for the completion of development projects. We customarily have agreements with our outside venture partners whereby the partners agree to reimburse the real estate venture or us for their share of any payments made under certain of these guarantees. At times, we also have agreements with certain of our outside venture partners whereby we agree to either indemnify the partners and/or the associated ventures with respect to certain contingent liabilities associated with operating assets or to reimburse our partner for its share of any payments made by them under certain guarantees. Guarantees (excluding environmental) customarily terminate either upon the satisfaction of specified circumstances or repayment of the underlying debt. Amounts that we may be required to pay in future periods in relation to guarantees associated with budget overruns or operating losses are not estimable. As of June 30, 2020, we had additional capital commitments and certain recorded guarantees to our unconsolidated real estate ventures totaling $57.2 million. As of June 30, 2020, we had no principal payment guarantees related to our unconsolidated real estate ventures. Additionally, with respect to borrowings of our consolidated entities, we have agreed, and may in the future agree, to (1) guarantee portions of the principal, interest and other amounts, (2) provide customary environmental indemnifications and nonrecourse carve-outs (e.g., guarantees against fraud, misrepresentation and bankruptcy) or (3) provide guarantees to lenders, tenants and other third parties for the completion of development projects. As of June 30, 2020, the aggregate amount of principal payment guarantees was $8.3 million for our consolidated entities. In connection with the Formation Transaction, we have an agreement with Vornado regarding tax matters (the "Tax Matters Agreement") that provides special rules that allocate tax liabilities if the distribution of JBG SMITH shares by Vornado, together with certain related transactions, is determined not to be tax-free. Under the Tax Matters Agreement, we may be required to indemnify Vornado against any taxes and related amounts and costs resulting from a violation by us of the Tax Matters Agreement.

Commitments and Contingencies

6 Months Ended

Jun. 30, 2020

Commitments and Contingencies Disclosure [Abstract]

17.Commitments and Contingencies

Insurance

We maintain general liability insurance with limits of $150.0 million per occurrence and in the aggregate, and property and rental value insurance coverage with limits of $1.5 billion per occurrence, with sub-limits for certain perils such as floods and earthquakes on each of our properties. We also maintain coverage, through our wholly owned captive insurance subsidiary, for a portion of the first loss on the above limits and for both terrorist acts and for nuclear, biological, chemical or radiological terrorism events with limits of $2.0 billion per occurrence. These policies are partially reinsured by third-party insurance providers.

We will continue to monitor the state of the insurance market and the scope and costs of coverage for acts of terrorism. We cannot anticipate what coverage will be available on commercially reasonable terms in the future. We are responsible for deductibles and losses in excess of the insurance coverage, which could be material.

Our debt, consisting of mortgages payable secured by our properties, a revolving credit facility and unsecured term loans, contains customary covenants requiring adequate insurance coverage. Although we believe that we currently have adequate insurance coverage, we may not be able to obtain an equivalent amount of coverage at reasonable costs in the future. If lenders insist on greater coverage than we are able to obtain, it could adversely affect the ability to finance or refinance our properties.

Construction Commitments

As of June 30, 2020, we had construction in progress that will require an additional $52.6 million to complete ($35.3 million related to our consolidated entities and $17.3 million related to our unconsolidated real estate ventures at our share), based on our current plans and estimates, which we anticipate will be primarily expended over the next one to two years. These capital expenditures are generally due as the work is performed, and we expect to finance them with debt proceeds, proceeds from asset recapitalizations and sales, issuance and sale of equity securities and available cash.

Environmental Matters

Most of our assets have been subject, at some point, to environmental assessments that are intended to evaluate the environmental condition of the subject and surrounding assets. The environmental assessments did not reveal any material environmental contamination that we believe would have a material adverse effect on our overall business, financial condition or results of operations, or that have not been anticipated and remediated during site redevelopment as required by law. Nevertheless, there can be no assurance that the identification of new areas of contamination, changes in the extent or known scope of contamination, the discovery of additional sites or changes in cleanup requirements would not result in significant cost to us. Environmental liabilities totaled $17.9 million as of both June 30, 2020 and December 31, 2019 and are included in "Other liabilities, net" in our balance sheets.

Other

There are various legal actions against us in the ordinary course of business. In our opinion, the outcome of such matters will not have a material adverse effect on our financial condition, results of operations or cash flows.

From time to time, we (or ventures in which we have an ownership interest) have agreed, and may in the future agree with respect to unconsolidated real estate ventures, to (1) guarantee portions of the principal, interest and other amounts in connection with borrowings, (2) provide customary environmental indemnifications and nonrecourse carve-outs (e.g., guarantees against fraud, misrepresentation and bankruptcy) in connection with borrowings or (3) provide guarantees to lenders and other third parties for the completion of development projects. We customarily have agreements with our outside venture partners whereby the partners agree to reimburse the real estate venture or us for their share of any payments made under certain of these guarantees. At times, we also have agreements with certain of our outside venture partners whereby we agree to either indemnify the partners and/or the associated ventures with respect to certain contingent liabilities associated with operating assets or to reimburse our partner for its share of any payments made by them under certain guarantees. Guarantees (excluding environmental) customarily terminate either upon the satisfaction of specified circumstances or repayment of the underlying debt. Amounts that we may be required to pay in future periods in relation to guarantees associated with budget overruns or operating losses are not estimable.

As of June 30, 2020, we had additional capital commitments and certain recorded guarantees to our unconsolidated real estate ventures totaling $57.2 million. As of June 30, 2020, we had no principal payment guarantees related to our unconsolidated real estate ventures.

Additionally, with respect to borrowings of our consolidated entities, we have agreed, and may in the future agree, to (1) guarantee portions of the principal, interest and other amounts, (2) provide customary environmental indemnifications and nonrecourse carve-outs (e.g., guarantees against fraud, misrepresentation and bankruptcy) or (3) provide guarantees to lenders, tenants and other third parties for the completion of development projects. As of June 30, 2020, the aggregate amount of principal payment guarantees was $8.3 million for our consolidated entities.

In connection with the Formation Transaction, we have an agreement with Vornado regarding tax matters (the "Tax Matters Agreement") that provides special rules that allocate tax liabilities if the distribution of JBG SMITH shares by Vornado, together with certain related transactions, is determined not to be tax-free. Under the Tax Matters Agreement, we may be required to indemnify Vornado against any taxes and related amounts and costs resulting from a violation by us of the Tax Matters Agreement.