JBG SMITH Properties (JBGS) 10-Q 7 May 19 2019 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2019	May 02, 2019
Document And Entity Information [Abstract]
Entity Registrant Name	JBG SMITH PROPERTIES
Entity Central Index Key	0001689796
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Document Type	10-Q
Document Period End Date	Mar. 31, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q1
Amendment Flag	false
Entity Common Stock, Shares Outstanding		134,093,995

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Real estate, at cost:
Land and improvements	$ 1,227,255	$ 1,371,874
Buildings and improvements	3,717,906	3,722,930
Construction in progress, including land	751,730	697,930
Real estate, at cost	5,696,891	5,792,734
Less accumulated depreciation	(1,075,309)	(1,051,875)
Real estate, net	4,621,582	4,740,859
Cash and cash equivalents	395,584	260,553
Restricted cash	17,877	138,979
Tenant and other receivables, net	49,979	46,568
Deferred rent receivable, net	152,323	143,473
Investments in and advances to unconsolidated real estate ventures	321,366	322,878
Other assets, net	297,525	264,994
Assets held for sale	168,458	78,981
TOTAL ASSETS	6,024,694	5,997,285
Liabilities:
Mortgages payable, net	1,835,842	1,838,381
Unsecured term loans, net	297,277	297,129
Accounts payable and accrued expenses	134,776	130,960
Other liabilities, net	174,434	181,606
Liabilities related to assets held for sale	486	3,717
Total liabilities	2,442,815	2,451,793
Commitments and contingencies
Redeemable noncontrolling interests	584,763	558,140
Shareholders' equity:
Preferred shares, $0.01 par value - 200,000 shares authorized, none issued	0	0
Common shares, $0.01 par value - 500,000 shares authorized; 122,594 and 120,937 shares issued and outstanding as of March 31, 2019 and December 31, 2018	1,227	1,210
Additional paid-in capital	3,150,133	3,155,256
Accumulated deficit	(151,157)	(176,018)
Accumulated other comprehensive income	(3,452)	6,700
Total shareholders' equity of JBG SMITH Properties	2,996,751	2,987,148
Noncontrolling interests in consolidated subsidiaries	365	204
Total equity	2,997,116	2,987,352
TOTAL LIABILITIES, REDEEMABLE NONCONTROLLING INTERESTS AND EQUITY	$ 6,024,694	$ 5,997,285

Consolidated and Combined Balan

Consolidated and Combined Balance Sheets (Parenthetical) - USD ($)	Mar. 31, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Preferred shares, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred shares, shares authorized	200,000,000	200,000,000
Preferred shares, shares issued	0	0
Preferred shares, shares outstanding	0	0
Common shares, par value (in dollars per share)	$ 0.01	$ 0.01
Common shares, shares authorized	500,000,000	500,000,000
Common shares, shares issued	122,594,000	120,937,000
Common shares, shares outstanding	122,594,000	120,937,000
Commitments and Contingencies

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
REVENUE
Property rentals	$ 119,413	$ 131,228
Third-party real estate services, including reimbursements	27,691	24,330
Other income	8,095	7,479
Total revenue	155,199	163,037
EXPENSES
Depreciation and amortization	48,719	49,160
Property operating	32,174	35,158
Real estate taxes	17,235	19,610
General and administrative:
Corporate and other	12,314	8,414
Third-party real estate services	28,066	22,609
Share-based compensation related to Formation Transaction and special equity awards	11,131	9,428
Transaction and other costs	4,895	4,221
Total expenses	154,534	148,600
Income (loss) from unconsolidated real estate ventures, net	3,601	(1,902)
Interest and other income, net	951	573
Interest expense	(17,174)	(19,257)
Gain on sale of real estate	39,033	455
Total other income (expense)	26,411	(20,131)
INCOME (LOSS) BEFORE INCOME TAX BENEFIT	27,076	(5,694)
Income tax benefit	1,172	908
NET INCOME (LOSS)	28,248	(4,786)
Net (income) loss attributable to redeemable noncontrolling interests	(3,387)	594
Net loss attributable to noncontrolling interests	0	2
NET INCOME (LOSS) ATTRIBUTABLE TO COMMON SHAREHOLDERS	$ 24,861	$ (4,190)
EARNINGS (LOSS) PER COMMON SHARE:
Earnings Per Share, Basic	$ 0.20	$ (0.04)
Earnings Per Share, Diluted	$ 0.20	$ (0.04)
Weighted average number of common shares outstanding — basic	122,573	117,955
Weighted average number of common shares outstanding — diluted	123,423	117,955

Consolidated and Combined State

Consolidated and Combined Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Statement of Comprehensive Income [Abstract]
NET INCOME (LOSS)	$ 28,248	$ (4,786)
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Change in fair value of derivative financial instruments	(10,696)	14,096
Reclassification of net (income) loss on derivative financial instruments from accumulated other comprehensive income into interest expense	(839)	1,035
Other comprehensive (loss) income	11,535	(15,131)
COMPREHENSIVE INCOME	16,713	10,345
Net (income) loss attributable to redeemable noncontrolling interests	3,387	(594)
Other comprehensive (income) loss attributable to redeemable noncontrolling interests	1,383	(1,876)
Net loss attributable to noncontrolling interests	0	2
COMPREHENSIVE INCOME (LOSS) ATTRIBUTABLE TO JBG SMITH PROPERTIES	$ 14,709	$ 9,065

Consolidated Statements of Equi

Consolidated Statements of Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Shares	Additional Paid-In Capital	Accumulated Deficit	Accumulated Other Comprehensive Income	Noncontrolling Interests in Consolidated Subsidiaries
Balance at beginning of period at Dec. 31, 2017	$ 2,974,814	$ 1,180	$ 3,063,625	$ (95,809)	$ 1,612	$ 4,206
Balance at beginning of period (in shares) at Dec. 31, 2017		117,955
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to common shareholders and noncontrolling interests	(4,192)			(4,190)		(2)
Distributions to noncontrolling interests	(482)					(482)
Redeemable noncontrolling interests redemption value adjustment and other comprehensive income allocation	15,973		17,849		(1,876)
Other Comprehensive Income (Loss), Net of Tax	15,131				15,131
Other	(548)		(548)
Balance at end of period (in shares) at Mar. 31, 2018		117,955
Balance at end of period at Mar. 31, 2018	3,000,696	$ 1,180	3,080,926	(99,999)	14,867	3,722
Balance at beginning of period at Dec. 31, 2018	$ 2,987,352	$ 1,210	3,155,256	(176,018)	6,700	204
Balance at beginning of period (in shares) at Dec. 31, 2018	120,937	120,937
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to common shareholders and noncontrolling interests	$ 24,861			24,861
Conversion of common limited partnership units to common shares		1,657
Conversion of common limited partnership units to common shares	(57,106)	$ (17)	(57,089)
Distributions to noncontrolling interests	(12)					(12)
Contributions from noncontrolling interests	173					173
Redeemable noncontrolling interests redemption value adjustment and other comprehensive income allocation	(60,829)		(62,212)		1,383
Other Comprehensive Income (Loss), Net of Tax	$ (11,535)				(11,535)
Balance at end of period (in shares) at Mar. 31, 2019	122,594	122,594
Balance at end of period at Mar. 31, 2019	$ 2,997,116	$ 1,227	$ 3,150,133	$ (151,157)	$ (3,452)	$ 365

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
OPERATING ACTIVITIES:
Net income (loss)	$ 28,248,000	$ (4,786,000)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Share-based compensation expense	16,589,000	13,099,000
Depreciation and amortization, including amortization of debt issuance costs	49,936,000	50,173,000
Deferred rent	(9,341,000)	(3,294,000)
(Income) loss from unconsolidated real estate ventures, net	(3,601,000)	1,902,000
Amortization of above- and below-market lease intangibles, net	(132,000)	(96,000)
Amortization of lease incentives	2,057,000	2,300,000
Return on capital from unconsolidated real estate ventures	398,000	3,764,000
Gain on sale of real estate	(39,033,000)	(455,000)
Net unrealized loss (gain) on derivative financial instruments not designated as cash flow hedges	48,000	(1,119,000)
Losses on operating lease receivables	1,568,000	354,000
Other non-cash items	519,000	141,000
Changes in operating assets and liabilities:
Tenant and other receivables	(4,185,000)	(6,038,000)
Other assets, net	1,647,000	(4,841,000)
Accounts payable and accrued expenses	(18,943,000)	(17,189,000)
Other liabilities, net	(7,867,000)	746,000
Net cash provided by operating activities	17,908,000	34,661,000
INVESTING ACTIVITIES:
Development costs, construction in progress and real estate additions	(68,667,000)	(84,643,000)
Deposits for real estate acquisitions	(8,525,000)	0
Proceeds from sale of real estate	117,676,000	2,154,000
Acquisition of interests in unconsolidated real estate ventures, net of cash acquired	0	(386,000)
Distributions of capital from unconsolidated real estate ventures	6,555,000	1,350,000
Investments in and advances to unconsolidated real estate ventures	(2,851,000)	(11,801,000)
Other	0	(19,000)
Net cash provided by (used in) investing activities	44,188,000	(93,345,000)
FINANCING ACTIVITIES:
Acquisition of ownership interest in consolidated real estate venture	0	(548,000)
Finance lease payments	(33,000)	(26,000)
Borrowings under mortgages payable	0	18,547,000
Borrowings under unsecured term loans	0	50,000,000
Repayments of mortgages payable	(3,065,000)	(68,221,000)
Dividends paid to common shareholders	(39,298,000)	(26,540,000)
Distributions to redeemable noncontrolling interests	(5,895,000)	(4,557,000)
Contributions from noncontrolling interests	124,000	0
Distributions to noncontrolling interests	0	(120,000)
Net cash used in financing activities	(48,167,000)	(31,465,000)
Net increase (decrease) in cash and cash equivalents and restricted cash	13,929,000	(90,149,000)
Cash and cash equivalents and restricted cash as of the beginning of the period	399,532,000	338,557,000
Cash and cash equivalents and restricted cash as of the end of the period	413,461,000	248,408,000
CASH AND CASH EQUIVALENTS AND RESTRICTED CASH AS OF END OF THE PERIOD:
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	399,532,000	338,557,000
SUPPLEMENTAL DISCLOSURE OF CASH FLOW AND NON-CASH INFORMATION:
Cash paid for interest (net of capitalized interest of $6,915 and $4,516 in 2019 and 2018)	15,489,000	16,584,000
Accrued capital expenditures included in accounts payable and accrued expenses	74,299,000	52,444,000
Write-off of fully depreciated assets	18,477,000	5,213,000
Fair value of OP Unit redemptions	(57,001,000)	0
Cash paid for amounts included in the measurement of lease liabilities for operating leases	$ 1,708,000	$ 0

Consolidated and Combined Sta_2

Consolidated and Combined Statements of Cash Flows (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Statement of Cash Flows [Abstract]
Capitalized interest	$ 6,915	$ 4,516

Organization and Basis of Prese

Organization and Basis of Presentation	3 Months Ended
	Mar. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Basis of Presentation	1. Organization and Basis of Presentation Organization JBG SMITH Properties ("JBG SMITH") was organized as a Maryland real estate investment trust ("REIT") on October 27, 2016 for the purpose of receiving, via the spin-off on July 17, 2017 (the "Separation"), substantially all of the assets and liabilities of Vornado Realty Trust's ("Vornado") Washington, D.C. segment. On July 18, 2017, JBG SMITH acquired the management business and certain assets and liabilities (the "JBG Assets") of The JBG Companies ("JBG") (the "Combination"). The Separation and the Combination are collectively referred to as the "Formation Transaction." JBG SMITH is hereinafter referred to as "we," "us," "our" or similar terms. References to "our share" refers to our ownership percentage of consolidated and unconsolidated assets in real estate ventures. Substantially all of our assets are held by, and our operations are conducted through, JBG SMITH Properties LP ("JBG SMITH LP"), our operating partnership. As of March 31, 2019 , we, as its sole general partner, controlled JBG SMITH LP and owned 89.0% of its common limited partnership units ("OP Units"). We own and operate a portfolio of high-quality commercial and multifamily assets, many of which are amenitized with ancillary retail. Our portfolio reflects our longstanding strategy of owning and operating assets within Metro-served submarkets in the Washington, D.C. metropolitan area that have high barriers to entry and key urban amenities, including being within walking distance of a Metro station. As of March 31, 2019 , our Operating Portfolio consists of 61 operating assets comprising 45 commercial assets totaling approximately 12.5 million square feet ( 10.9 million square feet at our share) and 16 multifamily assets totaling 6,315 units ( 4,531 units at our share). Additionally, we have (i) nine assets under construction comprising five commercial assets totaling approximately 1.2 million square feet ( 927,000 square feet at our share) and four multifamily assets totaling 1,476 units ( 1,298 units at our share); and (ii) 40 future development assets totaling approximately 22.1 million square feet ( 18.7 million square feet at our share) of estimated potential development density. Our revenues are derived primarily from leases with commercial and multifamily tenants, which include fixed rents and reimbursements from tenants for certain expenses such as real estate taxes, property operating expenses, and repairs and maintenance. In addition, our third-party asset management and real estate services business provides fee-based real estate services to third parties and the legacy funds (the "JBG Legacy Funds") formerly organized by JBG. Basis of Presentation The accompanying unaudited condensed consolidated financial statements and notes are prepared in accordance with accounting principles generally accepted in the United States of America ("GAAP") for interim financial information and with the instructions of Form 10-Q and Article 10 of Regulation S-X. Accordingly, these unaudited condensed consolidated financial statements do not contain certain information required in annual financial statements and notes as required under GAAP. In our opinion, all adjustments considered necessary for a fair presentation have been included, and all such adjustments are of a normal recurring nature. All intercompany transactions and balances have been eliminated. The results of operations for the three months ended March 31, 2019 and 2018 are not necessarily indicative of the results that may be expected for a full year. These condensed consolidated financial statements should be read in conjunction with our Annual Report on Form 10-K for the year ended December 31, 2018 , filed with the Securities and Exchange Commission. The accompanying condensed consolidated financial statements include the accounts of JBG SMITH and our wholly owned subsidiaries and those other entities, including JBG SMITH LP, in which we have a controlling financial interest, including where we have been determined to be the primary beneficiary of a variable interest entity ("VIE"). See Note 5 for additional information on our VIEs. The portions of the equity and net income of consolidated subsidiaries that are not attributable to JBG SMITH are presented separately as amounts attributable to noncontrolling interests in our condensed consolidated financial statements. References to the financial statements refer to our condensed consolidated financial statements as of March 31, 2019 and December 31, 2018 , and for the three months ended March 31, 2019 and 2018 . References to the balance sheets refer to our condensed consolidated balance sheets as of March 31, 2019 and December 31, 2018 . References to the statements of operations refer to our condensed consolidated statements of operations for the three months ended March 31, 2019 and 2018 . References to the statements of cash flows refer to our condensed consolidated statements of cash flows for the three months ended March 31, 2019 and 2018 . Reclassifications Certain prior period amounts have been reclassified to conform to the current period presentation as follows: • Reclassification of parking income totaling $6.4 million previously included in "Property rentals" for the three months ended March 31, 2018 to "Other income" in the statement of operations. • Reclassification of tenant reimbursements totaling $10.9 million for the three months ended March 31, 2018 to "Property rentals" in the statement of operations. • Reclassification of $4.3 million of expenses incurred in the operation and management of our properties that were previously included in "General and administrative expense: corporate and other" for the three months ended March 31, 2018 to "Property operating expenses" in the statement of operations. Income Taxes We have elected to be taxed as a REIT under sections 856-860 of the Internal Revenue Code of 1986, as amended (the "Code"). Under those sections, a REIT which distributes at least 90% of its REIT taxable income as dividends to its shareholders each year and which meets certain other conditions will not be taxed on that portion of its taxable income which is distributed to its shareholders. We intend to adhere to these requirements and maintain our REIT status in future periods. We also participate in the activities conducted by subsidiary entities which have elected to be treated as taxable REIT subsidiaries under the Code. As such, we are subject to federal, state, and local taxes on the income from these activities.

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2019
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Significant Accounting Policies There were no material changes to our significant accounting policies disclosed in our Annual Report on Form 10-K for the year ended December 31, 2018 , except as follows related to our adoption of Accounting Standards Update ("ASU") 2016-02, Leases ("Topic 842") as of January 1, 2019. Prior to the adoption of Topic 842, leases were accounted under Topic 840, Leases ("Topic 840"). Revenue Recognition We have leases with various tenants across our portfolio of properties, which generate rental income and operating cash flows for our benefit. Through these leases, we provide tenants with the right to control the use of our real estate assets, which tenants agree to use and control. The right to control our real estate assets conveys our tenants with substantially all of the economic benefits and the right to direct how and for what purpose the real estate is used throughout the period of use, thereby meeting the definition of a lease. Leases will be classified as either operating, sales-type or direct finance leases based on the principle of whether or not the lease is structured in effect as a financed purchase. Property rentals revenue includes base rent each tenant pays in accordance with the terms of its respective lease and is reported on a straight-line basis over the non-cancellable term of the lease, which includes the effects of periodic step-ups in rent and rent abatements under the lease. When a renewal option is included within the lease, we assess whether the option is reasonably certain of being exercised against relevant economic factors to determine whether or not the option period should be included as part of the lease term. Further, property rentals revenue includes tenant reimbursements revenue from the recovery of all or a portion of the operating expenses and real estate taxes of the respective assets, which are accrued as variable lease payments in the same periods as the related expenses are incurred. We commence rental revenue recognition when the tenant takes possession of the leased space or controls the physical use of the leased space and when the leased space is substantially ready for its intended use. In circumstances where we provide a tenant improvement allowance for improvements that are owned by the tenant, we recognize the allowance as a reduction of property rentals revenue on a straight-line basis over the term of the lease. Differences between rental revenue recognized and amounts due under the respective lease agreements are recorded as an increase or decrease to "Deferred rent receivable, net" on our balance sheets. Property rentals revenue also includes the amortization or accretion of acquired above-and below-market leases. We periodically evaluate the collectability of amounts due from tenants and recognize an adjustment to property rental revenue for the difference between cash received and revenue recognized for amounts deemed to be improbable of collection. Revenue recognized on leases whose collectability is not probable will be limited to cash received thereafter until such point that collection is deemed probable. Any changes to the provision for lease revenue determined to be not probable of collection is included in "Property rentals" in our statement of operations. We exercise judgment in assessing the probability of collection and consider payment history and current credit status in making this determination. Third-party real estate services revenue, including reimbursements, is determined in accordance with the terms specific to each arrangement and may include property and asset management fees or transactional fees for leasing, acquisition, development and construction, financing, and legal services provided. These fees are determined in accordance with the terms specific to each arrangement and are recognized as the related services are performed in accordance with ASU 2014-09, Revenue from Contracts with Customers, ("Topic 606"). Development and construction fees earned from providing services to our unconsolidated real estate ventures are recorded on a percentage of completion basis. Use of Estimates The preparation of the financial statements in conformity with GAAP requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the financial statements and the reported amounts of revenue and expenses during the reporting period. The most significant of these estimates include: (i) the underlying cash flows used in assessing impairment and (ii) the determination of useful lives for tangible and intangible assets. Actual results could differ from these estimates. Recent Accounting Pronouncements Adoption of Topic 842 We enter into various lease agreements to make our properties available for use by third parties in exchange for cash consideration or to obtain the right to use properties owned by third parties to administer our business operations. We account for these leases under Topic 842, which we adopted as of January 1, 2019 using a modified retrospective approach and by applying the several transitional practical expedients including the Comparatives Under 840 expedient, the Relief Package for existing leases and the Easement expedient for existing easements, but we did not elect the Hindsight expedient. The Comparatives Under 840 expedient allows us to not recast our comparative periods in the period of adoption, and the Relief Package and Easement expedients allow us to maintain our historical accounting conclusions on current leases as of the date of adoption with respect to whether a contract contains a lease, what a lease’s classification should be, what initial direct costs are capitalizable and whether a land easement constituted a lease. We made a policy election to forgo recording right-of-use assets and the related lease liabilities for leases with initial terms of 12 months or less. The adoption of Topic 842 did not result in a material change to our recognition of property rental revenue and did not impact our opening accumulated deficit balance, but did result in (i) a change in the presentation of property rentals, as of January 1, 2019, whereby tenant reimbursements revenue is included in “Property rentals” in our statement of operations and (ii) the recognition, as of January 1, 2019, of right-of-use assets totaling $35.3 million in “Other assets, net” and lease liabilities totaling $37.9 million in “Other liabilities, net” in our accompanying balance sheet, associated with our corporate office lease and various ground leases for which we are the lessee. The initial right-of-use assets comprised: (i) lease liabilities, (ii) $3.5 million of ground lease deferred rent payable reclassified from “Other liabilities, net" and (iii) $767,000 of identified net intangible assets and $140,000 of prepaid expenses both reclassified from “Other assets, net.” Further, effective January 1, 2019, any change to our assessment of whether previously recognized revenue is improbable of collection will be recognized as a deduction to revenue. Such amounts were recognized within “Property operating expense” prior to the adoption of Topic 842. Additionally, initial direct costs for both lessees and lessors is now limited to those costs that are incremental to the arrangement and would not have been incurred if the lease had not been obtained. As a result, we no longer capitalize internal leasing costs, which are now expensed as incurred within “Corporate and other - general and administrative costs.” Lessor Accounting Leases in which we are the lessor provide for the payment of fixed base rents payable monthly as well as reimbursements of real estate taxes, insurance and maintenance costs. We have elected a practical expedient which allows us to combine certain lease and non-lease components of our operating leases. Our non-lease components, which are not predominant within the contract, primarily relate to the reimbursement by our tenants of real estate taxes, insurance and maintenance costs, which vary each period, and are recognized together with fixed base rent in “Property rentals”, as variable lease income in the same periods as the related expenses are incurred. Certain commercial leases may also provide for the payment by the lessee of additional rents based on a percentage of sales, which are recorded as variable lease income in the period the additional rents are earned. The following is a summary of revenue from our non-cancellable leases included in the statements of operations: Three Months Ended March 31, 2019 (In thousands) Property rentals: Fixed $ 113,590 Variable 5,823 Total $ 119,413 As of March 31, 2019 , the undiscounted cash flows to be received from lease payments under our operating leases on an annual basis for the next five years and thereafter are as follows: Year ending December 31, Amount (In thousands) 2019 (1) $ 278,850 2020 323,967 2021 288,677 2022 258,016 2023 217,002 2024 194,847 Thereafter 1,048,678 ______________ (1) Amount is for the remainder of 2019. As of December 31, 2018 , under Topic 840, future base rental revenue under our non-cancellable operating leases is as follows: Year ending December 31, Amount (In thousands) 2019 $ 377,427 2020 321,205 2021 287,463 2022 256,352 2023 215,203 Thereafter 1,188,767 Lessee Accounting We are obligated under non-cancellable operating leases, including ground leases on certain of our properties through 2106 and our office leases. When a renewal option is included within the lease, we assess whether the option is reasonably certain of being exercised against relevant economic factors to determine whether or not the option period should be included as part of the lease term. Lease payments associated with renewal periods that we are reasonably certain will be exercised are included in the measurement of the corresponding lease liability and right-of-use asset. Rent expense for our operating leases is recognized on a straight-line basis over the expected lease term and is included in our statements of operations in either “Property operating expense” or “General and administrative expense: corporate and other” depending on the nature of the lease. Further, we are also obligated under a non-cancellable ground lease, which we classify as a finance lease. Since ownership of the land associated with our finance lease is reasonably certain to transfer to us upon the conclusion of the lease, we recorded $16.0 million to “Land and improvements” on our balance sheet when the lease commenced in 2017. Certain lease agreements include variable lease payments that, in the future, will vary based on changes in inflationary measures, market rates or our share of expenditures of the leased premises. We have elected the practical expedient not to separate lease and non-lease components for our ground and office leases. Our non-lease components primarily relate to property operating expenses associated with our office leases, which vary each period, and are recognized in rent expense when incurred. We discount our future lease payments for each lease to calculate the related lease liability using an estimated incremental borrowing rate computed based on observable corporate borrowing rates reflective of the general economic environment, taking into consideration our creditworthiness and various financing and asset specific considerations, adjusted to approximate a secured borrowing for the lease term. As of March 31, 2019 , the weighted average discount rate used in calculating lease liabilities for our active operating and finance leases were 5.2% and 5.8% , which have weighted average remaining lease terms of 20.1 and 7.8 years. As of March 31, 2019 , future minimum lease payments under our non-cancellable operating and finance leases are as follows: Year ending December 31, Operating Finance (In thousands) 2019 (1) $ 4,789 $ 791 2020 6,272 1,073 2021 6,201 1,095 2022 5,257 1,117 2023 2,000 1,139 2024 2,061 1,162 Thereafter 36,514 15,977 Total future minimum lease payments 63,094 22,354 Imputed interest (26,228 ) (6,683 ) Total (2) $ 36,866 $ 15,671 ______________ (1) Amounts are for the remainder of 2019. (2) The total for operating leases of $36.9 million corresponds to lease liabilities related to operating right-of-use assets and the total for finance leases of $15.7 million represents our finance lease liability, both of which are included in "Other liabilities, net" as of March 31, 2019 . See Note 8 for additional information. As of December 31, 2018 , under Topic 840, future minimum rental payments under our non-cancellable operating leases, capital leases and lease assumption liabilities are as follows: Year ending December 31, Amount (In thousands) 2019 $ 13,991 2020 13,710 2021 13,395 2022 12,554 2023 9,489 Thereafter 55,780 Total $ 118,919 For the three months ended March 31, 2019 , we incurred $663,000 of fixed operating and finance lease costs and $473,000 of variable operating lease costs.

Acquisitions, Disposals and Ass

Acquisitions, Disposals and Assets Held for Sale (Notes)	3 Months Ended
	Mar. 31, 2019
Discontinued Operations and Disposal Groups [Abstract]
Mergers, Acquisitions and Dispositions Disclosures [Text Block]	Acquisition, Disposition and Assets Held for Sale Acquisition In February 2019, we entered into a contract to purchase a stabilized multifamily asset located in Washington, D.C., which we intend to use as a replacement property in a 1031 like-kind exchange for the expected proceeds from the sale of the Mets 6, 7 and 8 land parcels to Amazon.com, Inc. Disposition The following is a summary of disposition activity for the three months ended March 31, 2019 : Date Disposed Assets Segment Location Total Square Feet Gross Sales Price Cash Proceeds from Sale Gain on Sale of Real Estate (In thousands) February 4, 2019 Commerce Executive / Commerce Metro Land (1) (2) Commercial / Other Reston, Virginia 388,562 $ 114,950 $ 117,676 $ 39,033 ______________ (1) The sale also included approximately 894,000 square feet of estimated potential development density. The sale was part of a reverse 1031 like-kind exchange. See Note 5 for additional information. (2) Cash proceeds include the reimbursement of $4.0 million of tenant improvement costs and leasing commissions paid by us prior to the closing. Assets Held for Sale As of March 31, 2019 and December 31, 2018 , we had certain real estate properties that were classified as held for sale. The amounts included in "Assets held for sale" in our balance sheets primarily represent real estate investment balances. The following is a summary of assets held for sale: Assets Segment Location Total Square Feet Assets Held for Sale Liabilities Related to Assets Held for Sale (In thousands) March 31, 2019 Pen Place (1) Other National Landing, Virginia — $ 73,949 $ 205 Mets 6, 7 and 8 (1) Other National Landing, Virginia — 94,509 281 — $ 168,458 $ 486 December 31, 2018 Commerce Executive / Commerce Metro Land (2) Commercial Reston, Virginia 388,562 $ 78,981 $ 3,717 _______________ (1) In March 2019, we entered into agreements for the sale of Pen Place and Mets 6, 7 and 8, future development assets having an aggregate estimated potential development density of up to approximately 4.1 million square feet, for approximately $293.9 million , subject to customary closing conditions. (2) As noted above, we sold Commerce Executive/Commerce Metro Land in February 2019 .

Investments in and Advances to

Investments in and Advances to Unconsolidated Real Estate Ventures	3 Months Ended
	Mar. 31, 2019
Equity Method Investments and Joint Ventures [Abstract]
Investments in and Advances to Unconsolidated Real Estate Ventures	Investments in and Advances to Unconsolidated Real Estate Ventures The following is a summary of the composition of our investments in and advances to unconsolidated real estate ventures: Real Estate Venture Partners Ownership Interest (1) March 31, 2019 December 31, 2018 (In thousands) CPPIB 55.0% - 63.7% $ 98,292 $ 97,521 Landmark 1.8% - 49.0% 82,149 84,320 CBREI Venture 5.0% - 64.0% 72,689 73,776 Berkshire Group 50.0% 45,227 43,937 Brandywine 30.0% 13,880 13,777 CIM Group and Pacific Life Insurance Company 16.7% 8,829 9,339 Other 220 128 Total investments in unconsolidated real estate ventures 321,286 322,798 Advances to unconsolidated real estate ventures 80 80 Total investments in and advances to unconsolidated real estate ventures $ 321,366 $ 322,878 _______________ (1) Ownership interests as of March 31, 2019 . We have multiple investments with certain venture partners with varying ownership interests. In February 2018, we entered into a real estate venture with CPPIB to develop and own 1900 N Street, an under construction commercial asset in Washington, D.C. We contributed 1900 N Street, valued at $95.9 million , to the real estate venture, and CPPIB has committed to contribute approximately $101.3 million to the venture for a 45.0% interest, which will reduce our ownership interest from 100.0% at the real estate venture's formation to 55.0% as contributions are funded. As of March 31, 2019 and December 31, 2018 , we have a zero investment balance in the real estate venture that owns 1101 17th Street and have suspended the equity method of accounting. We will recognize as income any future distributions from the venture until our share of unrecorded earnings and contributions exceed the cumulative excess distributions previously recognized in income. During the three months ended March 31, 2019 , we recognized income of $6.4 million related to net distributions from this venture, which is included in "Income from unconsolidated real estate ventures, net" in our statement of operations. The following is a summary of the debt of our unconsolidated real estate ventures: Weighted Average Effective (1) March 31, 2019 December 31, 2018 (In thousands) Variable rate (2) 5.00% $ 616,938 $ 461,704 Fixed rate (3) 3.93% 522,794 665,662 Unconsolidated real estate ventures - mortgages payable 1,139,732 1,127,366 Unamortized deferred financing costs (1,858 ) (1,998 ) Unconsolidated real estate ventures - mortgages payable, net (4) $ 1,137,874 $ 1,125,368 ______________ (1) Weighted average effective interest rate as of March 31, 2019 . (2) Includes variable rate mortgages payable with interest rate cap agreements. (3) Includes variable rate mortgages payable with interest rates fixed by interest rate swap agreements. (4) See Note 15 for additional information on guarantees of the debt of certain of our unconsolidated real estate ventures. The following is a summary of the financial information for our unconsolidated real estate ventures: March 31, 2019 December 31, 2018 Combined balance sheet information: (In thousands) Real estate, net $ 2,074,762 $ 2,050,985 Other assets, net (1) 191,210 169,264 Total assets $ 2,265,972 $ 2,220,249 Borrowings, net $ 1,137,874 $ 1,125,368 Other liabilities, net (1) 137,414 94,845 Total liabilities 1,275,288 1,220,213 Total equity 990,684 1,000,036 Total liabilities and equity $ 2,265,972 $ 2,220,249 ______________ (1) On January 1, 2019, our unconsolidated real estate ventures adopted Topic 842, which required us to record operating right-of-use assets totaling $52.4 million and related lease liabilities totaling $44.1 million . Three Months Ended March 31, 2019 2018 Combined income statement information: (In thousands) Total revenue $ 59,991 $ 73,173 Operating (loss) income (433 ) 4,374 Net loss (15,227 ) (4,675 )

Variable Interest Entities

Variable Interest Entities	3 Months Ended
	Mar. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Variable Interest Entities	Variable Interest Entities We hold various interests in entities deemed to be VIEs, which we evaluate at acquisition, formation, after a change in the ownership agreement or after a change in the real estate venture's economics to determine if the VIEs should be consolidated in our financial statements or should no longer be considered a VIE. Certain criteria we assess in determining whether the VIEs should be consolidated relate to our at-risk equity, our control over significant business activities, our voting rights, the noncontrolling interest kick-out rights and whether we are the primary beneficiary of the VIE. Unconsolidated VIEs As of March 31, 2019 and December 31, 2018 , we have interests in entities deemed to be VIEs that are in the development stage and do not hold sufficient equity at risk or conduct substantially all their operations on behalf of an investor with disproportionately few voting rights. Although we are engaged to act as the managing partner in charge of day-to-day operations of these investees, we are not the primary beneficiary of these VIEs as we do not hold unilateral power over activities that, when taken together, most significantly impact the respective VIE’s performance. We account for our investment in these entities under the equity method. As of March 31, 2019 and December 31, 2018 , the net carrying amounts of our investment in these entities were $224.7 million and $232.8 million , which are included in "Investments in and advances to unconsolidated real estate ventures" in our balance sheets. Our equity in the income of unconsolidated VIEs is included in "Income from unconsolidated real estate ventures, net" in our statements of operations. Our maximum exposure to loss in these entities is limited to our investments, construction commitments and debt guarantees. See Note 15 for additional information. Consolidated VIEs JBG SMITH LP is our most significant consolidated VIE. We hold the majority membership interest in the operating partnership, act as the general partner and exercise full responsibility, discretion and control over its day-to-day management. The noncontrolling interests of the operating partnership do not have substantive liquidation rights, substantive kick-out rights without cause, or substantive participating rights that could be exercised by a simple majority of noncontrolling interest members (including by such a member unilaterally). Because the noncontrolling interest holders do not have these rights, the operating partnership is a VIE. As general partner, we have the power to direct the core activities of the operating partnership that most significantly affect its performance, and through our majority interest in the operating partnership have both the right to receive benefits from and the obligation to absorb losses of the operating partnership. Accordingly, we are the primary beneficiary of the operating partnership and consolidate the operating partnership in our financial statements. As we conduct our business and hold our assets and liabilities through the operating partnership, the total assets and liabilities of the operating partnership comprise substantially all of our consolidated assets and liabilities. In conjunction with the acquisition of Potomac Yard Land Bay H located in Alexandria, Virginia in December 2018, we entered into a reverse Code Section 1031 like-kind exchange agreement with a third party intermediary. Until the earlier of the termination of the exchange agreement or 180 days after the acquisition date, the third party intermediary was the legal owner of the entity that owned this property. The agreement that governed the operations of this entity provided us with the power to direct the activities that most significantly impacted the entity's economic performance. This entity was deemed a VIE as of December 31, 2018 primarily because it may not have had sufficient equity at risk to finance its activities without additional subordinated financial support from other parties. We determined we were the primary beneficiary of the VIE as a result of having the power to direct the activities that most significantly impact its economic performance and the obligation to absorb losses, as well as the right to receive benefits, that could be potentially significant to the VIE. Accordingly, we consolidated the property and its operations as of the acquisition date. Legal ownership of this entity was transferred to us by the third-party intermediary after the sale of Commerce Executive/Commerce Metro Land in February 2019 . We consolidate VIEs in which we control the most significant business activities. These entities are VIEs because they are in the development stage and do not hold sufficient equity at risk. We are the primary beneficiaries of these VIEs because the noncontrolling interest holders do not have substantive kick-out or participating rights and we control all of the significant business activities. As of March 31, 2019 , excluding the operating partnership, we consolidated one VIE with total assets and liabilities of $74.2 million and $11.9 million . As of December 31, 2018 , excluding the operating partnership, we consolidated two VIEs with total assets and liabilities of $94.8 million and $43.4 million .

Other Assets, Net

Other Assets, Net	3 Months Ended
	Mar. 31, 2019
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Other Assets, Net	Other Assets, Net The following is a summary of other assets, net: March 31, 2019 December 31, 2018 (In thousands) Deferred leasing costs $ 210,565 $ 202,066 Accumulated amortization (74,217 ) (72,465 ) Deferred leasing costs, net 136,348 129,601 Other identified intangible assets, net 53,650 55,469 Lease intangible assets, net 31,319 34,390 Operating right-of-use assets, net (1) 34,151 — Prepaid expenses 5,386 6,482 Deferred financing costs on credit facility, net 4,316 4,806 Deposits 11,109 3,633 Derivative agreements, at fair value 1,894 10,383 Other 19,352 20,230 Total other assets, net $ 297,525 $ 264,994 ______________ (1) Related to our adoption of Topic 842 on January 1, 2019. See Note 2 for additional information.

Debt

Debt	3 Months Ended
	Mar. 31, 2019
Debt Disclosure [Abstract]
Debt	Debt Mortgages Payable The following is a summary of mortgages payable: Weighted Average (1) March 31, 2019 December 31, 2018 (In thousands) Variable rate (2) 4.22% $ 415,898 $ 308,918 Fixed rate (3) 3.92% 1,425,688 1,535,734 Mortgages payable 1,841,586 1,844,652 Unamortized deferred financing costs and premium/ discount, net (5,744 ) (6,271 ) Mortgages payable, net $ 1,835,842 $ 1,838,381 __________________________ (1) Weighted average effective interest rate as of March 31, 2019 . (2) Includes variable rate mortgages payable with interest rate cap agreements. (3) Includes variable rate mortgages payable with interest rates fixed by interest rate swap agreements. As of March 31, 2019 and December 31, 2018 , the net carrying value of real estate collateralizing our mortgages payable, excluding assets held for sale, totaled $2.3 billion . Our mortgage loans contain covenants that limit our ability to incur additional indebtedness on these properties and in certain circumstances, require lender approval of tenant leases and/or yield maintenance upon repayment prior to maturity. Certain of our mortgage loans are recourse to us. As of March 31, 2019 and December 31, 2018 , we had various interest rate swap and cap agreements with an aggregate notional value of $1.2 billion and $1.3 billion on certain of our mortgages payable, which mature on various dates concurrent with the maturity of the related mortgages payable. Credit Facility We have a $1.4 billion credit facility, consisting of a $1.0 billion revolving credit facility maturing in July 2021 , with two six -month extension options, a delayed draw $200.0 million unsecured term loan ("Tranche A-1 Term Loan") maturing in January 2023 , and a delayed draw $200.0 million unsecured term loan ("Tranche A-2 Term Loan") maturing in July 2024 . As of March 31, 2019 and December 31, 2018 , we had interest rate swaps with an aggregate notional value of $100.0 million , which effectively convert the variable interest rate applicable to our Tranche A-1 Term Loan to a fixed interest rate. The interest rate swaps mature in January 2023, concurrent with the maturity of our Tranche A-1 Term Loan. As of March 31, 2019 , we had an interest rate swap with a notional value of $64.0 million , which effectively converts the variable interest rate applicable to a portion of the outstanding balance of our Tranche A-2 Term Loan to a fixed interest rate. The interest rate swap matures in September 2020. The following is a summary of amounts outstanding under the credit facility: Interest Rate (1) March 31, 2019 December 31, 2018 (In thousands) Revolving credit facility (2) (3) (4) 3.59% $ — $ — Tranche A-1 Term Loan (5) 3.32% $ 100,000 $ 100,000 Tranche A-2 Term Loan (5) 4.39% 200,000 200,000 Unsecured term loans 300,000 300,000 Unamortized deferred financing costs, net (2,723 ) (2,871 ) Unsecured term loans, net $ 297,277 $ 297,129 __________________________ (1) Interest rate as of March 31, 2019 . (2) As of March 31, 2019 and December 31, 2018 , letters of credit with an aggregate face amount of $5.8 million and $5.7 million were provided under our revolving credit facility. (3) As of March 31, 2019 and December 31, 2018 , net deferred financing costs related to our revolving credit facility totaling $4.3 million and $4.8 million were included in "Other assets, net." (4) The interest rate for the revolving credit facility excludes a 0.15% facility fee. (5) The interest rate includes the impact of interest rate swap agreements.

Other Liabilities, Net

Other Liabilities, Net	3 Months Ended
	Mar. 31, 2019
Other Liabilities Disclosure [Abstract]
Other Liabilities, Net	Other Liabilities, Net The following is a summary of other liabilities, net: March 31, 2019 December 31, 2018 (In thousands) Lease intangible liabilities $ 40,179 $ 40,179 Accumulated amortization (26,628 ) (26,081 ) Lease intangible liabilities, net 13,551 14,098 Prepaid rent 20,345 21,998 Lease assumption liabilities 24,771 23,105 Lease incentive liabilities 17,528 9,317 Lease liabilities related to operating right-of-use assets (1) 36,866 — Finance lease liability 15,671 15,704 Security deposits 17,505 17,696 Environmental liabilities 17,898 17,898 Ground lease deferred rent payable (2) — 3,510 Net deferred tax liability 6,012 6,878 Dividends payable — 45,193 Other 4,287 6,209 Total other liabilities, net $ 174,434 $ 181,606 __________________________ (1) Related to our adoption of Topic 842 on January 1, 2019. See Note 2 for additional information. (2) In connection with our adoption of Topic 842 on January 1, 2019, the ground lease deferred rent payable balance as of December 31, 2018 was included in the initial determination of the operating right-of-use assets. See Note 2 for additional information.

Redeemable Noncontrolling Inter

Redeemable Noncontrolling Interests	3 Months Ended
	Mar. 31, 2019
Noncontrolling Interest [Abstract]
Redeemable Noncontrolling Interests	Redeemable Noncontrolling Interests JBG SMITH LP A portion of the OP Units held by persons other than JBG SMITH became redeemable for cash or, at our election, our common shares beginning on August 1, 2018, subject to certain limitations. During the three months ended March 31, 2019 , unitholders redeemed 1.7 million OP Units, which we elected to redeem for an equivalent number of our common shares. As of March 31, 2019 , outstanding OP Units totaled 15.2 million , representing an 11.0% ownership interest in JBG SMITH LP. On our balance sheets, our redeemable noncontrolling interests are presented at the higher of their redemption value at the end of each reporting period or their carrying value, with such adjustments recognized in "Additional paid-in capital." Redemption value is equivalent to the market value of one of our common shares at the end of the period multiplied by the number of vested OP Units outstanding. Consolidated Real Estate Venture We are a partner in a real estate venture that owns an under construction multifamily asset located at 965 Florida Avenue in Washington, D.C. Pursuant to the terms of the real estate venture agreement, we will fund all capital contributions until our ownership interest reaches a maximum of 97.0% . Our partner can redeem its interest for cash two years after delivery, but no later than seven years subsequent to delivery. As of March 31, 2019 , we held a 90.2% ownership interest in the real estate venture. Below is a summary of the activity of redeemable noncontrolling interests: Three Months Ended March 31, 2019 2018 JBG SMITH LP Consolidated Real Estate Venture Total JBG SMITH LP Consolidated Real Estate Venture Total (In thousands) Balance as of beginning of period $ 552,159 $ 5,981 $ 558,140 $ 603,717 $ 5,412 $ 609,129 OP Unit redemptions (57,001 ) — (57,001 ) — — — Long-term incentive partnership units ("LTIP Units") issued in lieu of cash bonuses (1) 3,135 — 3,135 — — — Net income (loss) attributable to redeemable noncontrolling interests 3,386 1 3,387 (592 ) (2 ) (594 ) Other comprehensive income (1,383 ) — (1,383 ) 1,876 — 1,876 Share-based compensation expense 16,273 — 16,273 12,942 — 12,942 Adjustment to redemption value 62,212 — 62,212 (17,849 ) — (17,849 ) Balance as of end of period $ 578,781 $ 5,982 $ 584,763 $ 600,094 $ 5,410 $ 605,504

Share-Based Payments and Employ

Share-Based Payments and Employee Benefits	3 Months Ended
	Mar. 31, 2019
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-Based Payments and Employee Benefits	Share-Based Payments and Employee Benefits LTIP and Time-Based LTIP Units During the three months ended March 31, 2019 , we granted 350,759 LTIP Units with time-based vesting requirements ("Time-Based LTIP Units") to management and other employees with a weighted average grant-date fair value of $34.24 per unit that vest primarily over four years, 25.0% per year, subject to continued employment. Compensation expense for these units is being recognized primarily over a four -year period. The aggregate grant-date fair value of these Time-Based LTIP Units granted during the three months ended March 31, 2019 was $12.0 million valued using Monte Carlo simulations. Additionally, during the three months ended March 31, 2019 , we granted 91,636 of fully vested LTIP Units, with a grant-date fair value of $34.21 per unit, to certain executives who elected to receive all or a portion of any cash bonus paid in 2019, related to 2018 service, as LTIP Units. Compensation expense totaling $3.1 million for these LTIP Units was recognized in 2018. The significant assumptions used to value LTIP and Time-Based LTIP Units included: Expected volatility 22.0% to 24.0% Risk-free interest rate 2.6 % Post-grant restriction periods 2 years Performance-Based LTIP Units During the three months ended March 31, 2019 , we granted 477,640 LTIP Units with performance-based vesting requirements ("Performance-Based LTIP Units") to management and other employees with a weighted average grant-date fair value of $19.49 per unit. Our Performance-Based LTIP Units have a three -year performance period. Fifty percent of any Performance-Based LTIP Units that are earned vest at the end of the three -year performance period and the remaining 50% on the fourth anniversary of the date of grant, subject to continued employment. The aggregate grant-date fair value of the Performance-Based LTIP Units granted during the three months ended March 31, 2019 was $9.3 million valued using Monte Carlo simulations. Compensation expense for the Performance-Based LTIP Units is being recognized over a four -year period. The significant assumptions used to value the Performance-Based LTIP Units included: Expected volatility 22.0% to 23.0% Dividend yield 2.4% to 2.5% Risk-free interest rate 2.5% to 2.6% Share-Based Compensation Expense Share-based compensation expense is summarized as follows: Three Months Ended March 31, 2019 2018 (In thousands) Time-Based LTIP Units $ 2,934 $ 2,357 Performance-Based LTIP Units 2,208 1,157 Other equity awards (1) 1,059 784 Share-based compensation expense - other 6,201 4,298 Formation Awards 1,660 1,578 OP Units (2) 7,931 7,781 LTIP Units (2) 108 69 Special Performance-Based LTIP Units 644 — Special Time-Based LTIP Units 788 — Share-based compensation related to Formation Transaction and special equity awards (3) 11,131 9,428 Total share-based compensation expense 17,332 13,726 Less amount capitalized (743 ) (627 ) Share-based compensation expense $ 16,589 $ 13,099 ______________________________________________ (1) Includes compensation expense for certain executives who have elected to receive all or a portion of any cash bonus that may be paid in future periods related to past service in the form of fully vested LTIP Units and expense related to our employee share purchase plan. (2) Represents share-based compensation expense for LTIP Units and OP Units subject to post-Combination employment obligations. (3) Included in "General and administrative expense: Share-based compensation related to Formation Transaction and special equity awards" in the accompanying statements of operations. As of March 31, 2019 , we had $123.6 million of total unrecognized compensation expense related to unvested share-based payment arrangements (unvested OP Units, Formation Awards, Time-Based LTIP Units, Special Time-Based LTIP Units, Performance-Based LTIP Units and Special Performance-Based LTIP Units). This expense is expected to be recognized over a weighted average period of 2.7 years.

Interest Expense Interest Expen

Interest Expense Interest Expense	3 Months Ended
	Mar. 31, 2019
Interest Expense [Abstract]
Interest Income and Interest Expense Disclosure [Text Block]	Interest Expense The following is a summary of interest expense included in the statements of operations: Three Months Ended March 31, 2019 2018 (In thousands) Interest expense $ 22,877 $ 23,675 Amortization of deferred financing costs 1,164 1,217 Net unrealized loss (gain) on derivative financial instruments 48 (1,119 ) Capitalized interest (6,915 ) (4,516 ) Interest expense $ 17,174 $ 19,257

Earnings (Loss) Per Common Shar

Earnings (Loss) Per Common Share	3 Months Ended
	Mar. 31, 2019
Earnings Per Share [Abstract]
Earnings (Loss) Per Common Share	Earnings (Loss) Per Common Share The following summarizes the calculation of basic and diluted earnings (loss) per common share and provides a reconciliation of the amounts of net income (loss) attributable to common shareholders used in calculating basic and diluted earnings (loss) per common share: Three Months Ended March 31, 2019 2018 (In thousands, except per share amounts) Net income (loss) $ 28,248 $ (4,786 ) Net (income) loss attributable to redeemable noncontrolling (3,387 ) 594 Net loss attributable to noncontrolling interests — 2 Net income (loss) attributable to common shareholders $ 24,861 $ (4,190 ) Weighted average number of common shares outstanding — basic 122,573 117,955 Effect of dilutive securities 850 — Weighted average number of common shares outstanding — diluted 123,423 117,955 Earnings (loss) per common share: Basic $ 0.20 $ (0.04 ) Diluted $ 0.20 $ (0.04 ) The effect of the redemption of OP Units and Time-Based LTIP Units that were outstanding as of March 31, 2019 and 2018 is excluded in the computation of diluted earnings per common share, as the assumed exchange of such units for common shares on a one-for-one basis was antidilutive (the assumed redemption of these units would have no impact on the determination of diluted earnings per share). Since OP Units and Time-Based LTIP Units, which are held by noncontrolling interests, are attributed gains and losses at an identical proportion to the common shareholders, the gains attributable and their equivalent weighted average OP Unit and Time-Based LTIP Unit impact are excluded from net income (loss) available to common shareholders and from the weighted average number of common shares outstanding in calculating diluted earnings per common share. Performance-Based LTIP Units, Special Performance-Based LTIP Units and Formation Awards, which totaled 3.9 million and 3.8 million for the three months ended March 31, 2019 and 2018 , were excluded from the calculation of diluted earnings per common share as they were antidilutive, but potentially could be dilutive in the future.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2019
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis To manage or hedge our exposure to interest rate risk, we follow established risk management policies and procedures, including the use of a variety of derivative financial instruments. We do not enter into derivative financial instruments for speculative purposes. As of March 31, 2019 and December 31, 2018 , we had various derivative financial instruments consisting of interest rate swap and cap agreements that are measured at fair value on a recurring basis. The net unrealized (loss) gain on our derivative financial instruments designated as cash flow hedges was $(3.2) million and $8.3 million as of March 31, 2019 and December 31, 2018 and was recorded in "Accumulated other comprehensive income" in the balance sheet, of which a portion was reclassified to "Redeemable noncontrolling interests" as of March 31, 2019 and December 31, 2018 . Within the next 12 months, we expect to reclassify $1.8 million as a decrease to interest expense. The net unrealized (loss) gain on our derivative financial instruments not designated as cash flow hedges was $(48,000) and $1.1 million for the three months ended March 31, 2019 and 2018 and is recorded in "Interest expense" in our statements of operations and "Net unrealized gain on derivative financial instruments not designated as cash flow hedges" in our statements of cash flows. Topic 820, Fair Value Measurement and Disclosures, establishes a fair value hierarchy that prioritizes observable and unobservable inputs used to measure fair value into three levels: Level 1 — quoted prices (unadjusted) in active markets that are accessible at the measurement date for assets or liabilities; Level 2 — observable prices that are based on inputs not quoted in active markets, but corroborated by market data; and Level 3 — unobservable inputs that are used when little or no market data is available. The fair values of the derivative financial instruments are based on the estimated amounts we would receive or pay to terminate the contracts at the reporting date and are determined using interest rate pricing models and observable inputs. The derivative financial instruments are classified within Level 2 of the valuation hierarchy. The following are assets and liabilities measured at fair value on a recurring basis: Fair Value Measurements Total Level 1 Level 2 Level 3 March 31, 2019 (In thousands) Derivative financial instruments designated as cash flow hedges: Classified as assets in "Other assets, net" $ 1,892 $ — $ 1,892 $ — Classified as liabilities in "Other liabilities, net" 4,099 — 4,099 — Derivative financial instruments not designated as cash flow hedges: Classified as assets in "Other assets, net" 2 — 2 — December 31, 2018 Derivative financial instruments designated as cash flow hedges: Classified as assets in "Other assets, net" $ 7,913 $ — $ 7,913 $ — Classified as liabilities in "Other liabilities, net" 1,723 — 1,723 — Derivative financial instruments not designated as cash flow hedges: Classified as assets in "Other assets, net" 2,470 — 2,470 — The fair values of our derivative financial instruments were determined using widely accepted valuation techniques, including discounted cash flow analysis on the expected cash flows of the derivative financial instrument. This analysis reflected the contractual terms of the derivative, including the period to maturity, and used observable market-based inputs, including interest rate market data and implied volatilities in such interest rates. While it was determined that the majority of the inputs used to value the derivatives fall within Level 2 of the fair value hierarchy under authoritative accounting guidance, the credit valuation adjustments associated with the derivatives also utilized Level 3 inputs, such as estimates of current credit spreads to evaluate the likelihood of default. However, as of March 31, 2019 and December 31, 2018 , the significance of the impact of the credit valuation adjustments on the overall valuation of the derivative financial instruments was assessed and it was determined that these adjustments were not significant to the overall valuation of the derivative financial instruments. As a result, it was determined that the derivative financial instruments in their entirety should be classified in Level 2 of the fair value hierarchy. The net unrealized gain included in "Other comprehensive income'' was primarily attributable to the net change in unrealized gains or losses related to the interest rate swaps that were outstanding as of March 31, 2019 and December 31, 2018 , none of which were reported in the statements of operations because they were documented and qualified as hedging instruments. Financial Assets and Liabilities Not Measured at Fair Value As of March 31, 2019 and December 31, 2018 , all financial instruments and liabilities were reflected in our balance sheets at amounts which, in our estimation, reasonably approximated their fair values, except for the following: March 31, 2019 December 31, 2018 Carrying Amount (1) Fair Value Carrying Amount (1) Fair Value (In thousands) Financial liabilities: Mortgages payable $ 1,841,586 $ 1,873,323 $ 1,844,652 $ 1,870,078 Unsecured term loans 300,000 304,583 300,000 300,727 ______________________________________ ( 1) The carrying amount consists of principal only. The fair value of the mortgages payable and unsecured term loans was determined using Level 2 inputs of the fair value hierarchy.

Segment Information

Segment Information	3 Months Ended
	Mar. 31, 2019
Segment Reporting [Abstract]
Segment Information	Segment Information We review operating and financial data for each property on an individual basis; therefore, each of our individual properties is a separate operating segment. As of December 31, 2018 , we redefined our reportable segments to be aligned with our new method of internal reporting and the way our Chief Executive Officer, who is also our Chief Operating Decision Maker ("CODM"), makes key operating decisions, evaluates financial results, allocates resources and manages our business. Accordingly, we aggregate our operating segments into three reportable segments (commercial, multifamily, and third-party asset management and real estate services) based on the economic characteristics and nature of our assets and services. To conform to the current period presentation, we have reclassified the prior period segment financial data for certain properties that had been classified as part of other to the commercial and multifamily segments and the elimination of intersegment activity has been included as part of other for the three months ended March 31, 2018 . The commercial segment was previously referred to as the office segment. The CODM measures and evaluates the performance of our operating segments, with the exception of the third-party asset management and real estate services business, based on the net operating income ("NOI") of properties within each segment. NOI includes property rental revenue and other property operating income, and deducts property operating expenses and real estate taxes. With respect to the third-party asset management and real estate services business, the CODM reviews revenues streams generated by this segment ("Third-party real estate services, including reimbursements"), as well as the expenses attributable to the segment ("General and administrative: third-party real estate services"), which are disclosed separately in the statements of operations. Management company assets primarily consist of management and leasing contracts with a net book value of $36.8 million and $38.6 million and are classified in "Other assets, net" in the balance sheets as of March 31, 2019 and December 31, 2018 . Consistent with internal reporting presented to our CODM and our definition of NOI, the third-party asset management and real estate services operating results are excluded from the NOI data below. The following table reflects the reconciliation of net income (loss) attributable to common shareholders to consolidated NOI: Three Months Ended March 31, 2019 2018 (In thousands) Net income (loss) attributable to common shareholders $ 24,861 $ (4,190 ) Add: Depreciation and amortization expense 48,719 49,160 General and administrative expense: Corporate and other 12,314 8,414 Third-party real estate services 28,066 22,609 Share-based compensation related to Formation Transaction and 11,131 9,428 Transaction and other costs 4,895 4,221 Interest expense 17,174 19,257 Income tax benefit (1,172 ) (908 ) Net income (loss) attributable to redeemable noncontrolling interests 3,387 (594 ) Less: Third-party real estate services, including reimbursements 27,691 24,330 Other income (excluding parking income of $6,455 and $6,363 in 2019 and 2018) 1,640 1,116 Income (loss) from unconsolidated real estate ventures, net 3,601 (1,902 ) Interest and other income, net 951 573 Gain on sale of real estate 39,033 455 Net loss attributable to noncontrolling interests — 2 Consolidated NOI $ 76,459 $ 82,823 Below is a summary of NOI by segment. Items classified in the Other column include future development assets, corporate entities and the elimination of intersegment activity. Three Months Ended March 31, 2019 Commercial Multifamily Other Total (In thousands) Property rentals revenue $ 96,247 $ 28,249 $ (5,083 ) $ 119,413 Other property operating income 6,375 80 — 6,455 Total property revenue 102,622 28,329 (5,083 ) 125,868 Property expense: — Property operating 30,481 7,967 (6,274 ) 32,174 Real estate taxes 12,513 3,548 1,174 17,235 Total property expense 42,994 11,515 (5,100 ) 49,409 Consolidated NOI $ 59,628 $ 16,814 $ 17 $ 76,459 Three Months Ended March 31, 2018 Commercial Multifamily Other Total (In thousands) Property rentals revenue $ 105,564 $ 25,837 $ (173 ) $ 131,228 Other property operating income 6,244 90 29 6,363 Total property revenue 111,808 25,927 (144 ) 137,591 Property expense: Property operating 25,837 7,287 2,034 35,158 Real estate taxes 14,781 3,547 1,282 19,610 Total property expense 40,618 10,834 3,316 54,768 Consolidated NOI $ 71,190 $ 15,093 $ (3,460 ) $ 82,823 The following is a summary of certain balance sheet data by segment: Commercial Multifamily Other Total March 31, 2019 (In thousands) Real estate, at cost $ 3,650,134 $ 1,702,845 $ 343,912 $ 5,696,891 Investments in and advances to unconsolidated real estate ventures 175,511 109,850 36,005 321,366 Total assets (1) 3,695,905 1,571,388 757,401 6,024,694 December 31, 2018 Real estate, at cost $ 3,634,472 $ 1,656,974 $ 501,288 $ 5,792,734 Investments in and advances to unconsolidated real estate ventures 177,173 109,232 36,473 322,878 Total assets (1) 3,707,255 1,528,177 761,853 5,997,285 __________________________ (1) Includes assets held for sale. See Note 3 for additional information.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Insurance We maintain general liability insurance with limits of $200.0 million per occurrence and in the aggregate, and property and rental value insurance coverage with limits of $2.0 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 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 mortgage loans secured by our properties, revolving credit facility and unsecured term loans contain 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 March 31, 2019 , we have construction in progress that will require an additional $456.9 million to complete ( $385.9 million related to our consolidated entities and $71.1 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 two to three 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 Each of our properties has been subjected to varying degrees of environmental assessment at various times. 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 total $17.9 million as of March 31, 2019 and December 31, 2018 , and primarily relate to a liability to remediate pre-existing environmental matters at Potomac Yard Land Bay H, which was acquired in December 2018. 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 their borrowings, (2) provide customary environmental indemnifications and nonrecourse carve-outs (e.g., guarantees against fraud, misrepresentation and bankruptcy) in connection with their borrowings and (3) provide guarantees to lenders and other third parties for the completion of development projects. We customarily have agreements with our outside 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. Amounts that may be required to be paid in future periods in relation to budget overruns or operating losses that are also included in some of our guarantees are not estimable. Guarantees (excluding environmental) terminate either upon the satisfaction of specified circumstances or repayment of the underlying debt. At times, we have agreements with our outside partners whereby we agree to reimburse our partner for their share of any payments made by them under certain guarantees. As of March 31, 2019 , we had no principal payment guarantees for our unconsolidated real estate ventures. We also may guarantee portions of the principal, interest and other amounts in connection with the borrowings of our consolidated entities. As of March 31, 2019 , the aggregate amount of principal payment guarantees was $8.3 million for our consolidated entities. As of March 31, 2019 , we expect to fund additional capital to certain of our unconsolidated investments totaling approximately $48.6 million . 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 not 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, or from the taking of certain restricted actions by us.

Transactions with Vornado and R

Transactions with Vornado and Related Parties	3 Months Ended
	Mar. 31, 2019
Related Party Transactions [Abstract]
Related Party Transactions Disclosure [Text Block]	Transactions with Vornado and Related Parties Transactions with Vornado In connection with the Formation Transaction, we entered into an agreement with Vornado under which Vornado provided operational support for an initial period of up to two years. Such support services have been substantially completed. These services included information technology, financial reporting and payroll services. The charges for these services were based on an hourly or per transaction fee arrangement including reimbursement for overhead and out-of-pocket expenses totaling $1.2 million for the three months ended March 31, 2018 . Pursuant to agreements, we are providing Vornado with leasing and property management services for certain of its assets that were not part of the Separation. The total revenue related to these services for the three months ended March 31, 2019 and 2018 were $488,000 and $600,000 . We believe that the terms of these agreements are comparable to those that would have been negotiated based on market rates. We have agreements that are terminable on the second anniversary of the Combination with Building Maintenance Services ("BMS"), a wholly owned subsidiary of Vornado, to supervise cleaning, engineering and security services at our properties. We paid BMS $5.2 million and $4.0 million during the three months ended March 31, 2019 and 2018 , which are included in "Property operating expenses" in our statements of operations. In connection with the Formation Transaction, we have a Tax Matters Agreement with Vornado. See Note 15 for additional information. We entered into a consulting agreement with Mitchell Schear, a member of our Board of Trustees and formerly the president of Vornado’s Washington, D.C. segment. The consulting agreement expired on December 31, 2017 and provided for the payment of consulting fees and expenses at the rate of $169,400 per month for the 24 months following the Separation, including after the expiration of the consulting agreement. The amount due under this consulting agreement of $4.1 million was expensed in connection with the Combination. As of March 31, 2019 , the remaining liability is $432,000 . Transactions with JBG Legacy Funds Our third-party asset management and real estate services business provides fee-based real estate services to third parties and the JBG Legacy Funds. We provide services for the benefit of the JBG Legacy Funds that own interests in the assets retained by the JBG Legacy Funds. In connection with the contribution of the JBG Assets to us, it was determined that the general partner and managing member interests in the JBG Legacy Funds that were held by former JBG executives (and who became members of our management team and/or Board of Trustees) would not be transferred to us and remain under the control of these individuals. In addition, certain members of our senior management and Board of Trustees have an ownership interest in the JBG Legacy Funds and own carried interests in each fund and in certain of our real estate ventures that entitles them to receive additional compensation if the fund or real estate venture achieves certain return thresholds. This third-party real estate services revenue, including reimbursements, from these JBG Legacy Funds for the three months ended March 31, 2019 and 2018 was $8.4 million and $8.6 million . As of March 31, 2019 and December 31, 2018 , we had receivables from the JBG Legacy Funds totaling $3.9 million and $3.6 million for such services. We rent our corporate offices from an unconsolidated real estate venture and incurred expenses totaling $1.2 million during the three months ended March 31, 2019 and 2018 , which is recorded in "General and administrative expense: Corporate and other" in our statements of operations.

Subsequent Events

Subsequent Events	3 Months Ended
	Mar. 31, 2019
Subsequent Events [Abstract]
Subsequent Events	Subsequent Event In April 2019, we closed an underwritten public offering of 11.5 million common shares (including 1.5 million common shares related to the exercise of the underwriters' option to cover overallotments) at $42.00 per share, which generated net proceeds, after deducting the underwriting discounts and commissions and other estimated offering expenses, of approximately $472.3 million . We intend to use the net proceeds to fund development opportunities and for general corporate purposes. In April 2019, we repaid the mortgage debt totaling approximately $293.6 million at The Bartlett and Fort Totten Square. In May 2019, our Board of Trustees declared a quarterly dividend of $0.225 per common share, payable on May 24, 2019 to shareholders of record on May 13, 2019 .

Organization and Basis of Pre_2

Organization and Basis of Presentation Accounting (Policies)	3 Months Ended
	Mar. 31, 2019
Accounting Policies [Abstract]
Basis of Accounting [Text Block]	Basis of Presentation The accompanying unaudited condensed consolidated financial statements and notes are prepared in accordance with accounting principles generally accepted in the United States of America ("GAAP") for interim financial information and with the instructions of Form 10-Q and Article 10 of Regulation S-X. Accordingly, these unaudited condensed consolidated financial statements do not contain certain information required in annual financial statements and notes as required under GAAP. In our opinion, all adjustments considered necessary for a fair presentation have been included, and all such adjustments are of a normal recurring nature. All intercompany transactions and balances have been eliminated. The results of operations for the three months ended March 31, 2019 and 2018 are not necessarily indicative of the results that may be expected for a full year. These condensed consolidated financial statements should be read in conjunction with our Annual Report on Form 10-K for the year ended December 31, 2018 , filed with the Securities and Exchange Commission. The accompanying condensed consolidated financial statements include the accounts of JBG SMITH and our wholly owned subsidiaries and those other entities, including JBG SMITH LP, in which we have a controlling financial interest, including where we have been determined to be the primary beneficiary of a variable interest entity ("VIE"). See Note 5 for additional information on our VIEs. The portions of the equity and net income of consolidated subsidiaries that are not attributable to JBG SMITH are presented separately as amounts attributable to noncontrolling interests in our condensed consolidated financial statements. References to the financial statements refer to our condensed consolidated financial statements as of March 31, 2019 and December 31, 2018 , and for the three months ended March 31, 2019 and 2018 . References to the balance sheets refer to our condensed consolidated balance sheets as of March 31, 2019 and December 31, 2018 . References to the statements of operations refer to our condensed consolidated statements of operations for the three months ended March 31, 2019 and 2018 . References to the statements of cash flows refer to our condensed consolidated statements of cash flows for the three months ended March 31, 2019 and 2018 .
Income Tax, Policy [Policy Text Block]	Income Taxes We have elected to be taxed as a REIT under sections 856-860 of the Internal Revenue Code of 1986, as amended (the "Code"). Under those sections, a REIT which distributes at least 90% of its REIT taxable income as dividends to its shareholders each year and which meets certain other conditions will not be taxed on that portion of its taxable income which is distributed to its shareholders. We intend to adhere to these requirements and maintain our REIT status in future periods. We also participate in the activities conducted by subsidiary entities which have elected to be treated as taxable REIT subsidiaries under the Code. As such, we are subject to federal, state, and local taxes on the income from these activities.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2019
Accounting Policies [Abstract]
Revenue Recognition, Policy [Policy Text Block]	Revenue Recognition We have leases with various tenants across our portfolio of properties, which generate rental income and operating cash flows for our benefit. Through these leases, we provide tenants with the right to control the use of our real estate assets, which tenants agree to use and control. The right to control our real estate assets conveys our tenants with substantially all of the economic benefits and the right to direct how and for what purpose the real estate is used throughout the period of use, thereby meeting the definition of a lease. Leases will be classified as either operating, sales-type or direct finance leases based on the principle of whether or not the lease is structured in effect as a financed purchase. Property rentals revenue includes base rent each tenant pays in accordance with the terms of its respective lease and is reported on a straight-line basis over the non-cancellable term of the lease, which includes the effects of periodic step-ups in rent and rent abatements under the lease. When a renewal option is included within the lease, we assess whether the option is reasonably certain of being exercised against relevant economic factors to determine whether or not the option period should be included as part of the lease term. Further, property rentals revenue includes tenant reimbursements revenue from the recovery of all or a portion of the operating expenses and real estate taxes of the respective assets, which are accrued as variable lease payments in the same periods as the related expenses are incurred. We commence rental revenue recognition when the tenant takes possession of the leased space or controls the physical use of the leased space and when the leased space is substantially ready for its intended use. In circumstances where we provide a tenant improvement allowance for improvements that are owned by the tenant, we recognize the allowance as a reduction of property rentals revenue on a straight-line basis over the term of the lease. Differences between rental revenue recognized and amounts due under the respective lease agreements are recorded as an increase or decrease to "Deferred rent receivable, net" on our balance sheets. Property rentals revenue also includes the amortization or accretion of acquired above-and below-market leases. We periodically evaluate the collectability of amounts due from tenants and recognize an adjustment to property rental revenue for the difference between cash received and revenue recognized for amounts deemed to be improbable of collection. Revenue recognized on leases whose collectability is not probable will be limited to cash received thereafter until such point that collection is deemed probable. Any changes to the provision for lease revenue determined to be not probable of collection is included in "Property rentals" in our statement of operations. We exercise judgment in assessing the probability of collection and consider payment history and current credit status in making this determination. Third-party real estate services revenue, including reimbursements, is determined in accordance with the terms specific to each arrangement and may include property and asset management fees or transactional fees for leasing, acquisition, development and construction, financing, and legal services provided. These fees are determined in accordance with the terms specific to each arrangement and are recognized as the related services are performed in accordance with ASU 2014-09, Revenue from Contracts with Customers, ("Topic 606"). Development and construction fees earned from providing services to our unconsolidated real estate ventures are recorded on a percentage of completion basis.
Use of Estimates, Policy [Policy Text Block]	Use of Estimates The preparation of the financial statements in conformity with GAAP requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the financial statements and the reported amounts of revenue and expenses during the reporting period. The most significant of these estimates include: (i) the underlying cash flows used in assessing impairment and (ii) the determination of useful lives for tangible and intangible assets. Actual results could differ from these estimates.
New Accounting Pronouncements, Policy [Policy Text Block]	Recent Accounting Pronouncements Adoption of Topic 842 We enter into various lease agreements to make our properties available for use by third parties in exchange for cash consideration or to obtain the right to use properties owned by third parties to administer our business operations. We account for these leases under Topic 842, which we adopted as of January 1, 2019 using a modified retrospective approach and by applying the several transitional practical expedients including the Comparatives Under 840 expedient, the Relief Package for existing leases and the Easement expedient for existing easements, but we did not elect the Hindsight expedient. The Comparatives Under 840 expedient allows us to not recast our comparative periods in the period of adoption, and the Relief Package and Easement expedients allow us to maintain our historical accounting conclusions on current leases as of the date of adoption with respect to whether a contract contains a lease, what a lease’s classification should be, what initial direct costs are capitalizable and whether a land easement constituted a lease. We made a policy election to forgo recording right-of-use assets and the related lease liabilities for leases with initial terms of 12 months or less. The adoption of Topic 842 did not result in a material change to our recognition of property rental revenue and did not impact our opening accumulated deficit balance, but did result in (i) a change in the presentation of property rentals, as of January 1, 2019, whereby tenant reimbursements revenue is included in “Property rentals” in our statement of operations and (ii) the recognition, as of January 1, 2019, of right-of-use assets totaling $35.3 million in “Other assets, net” and lease liabilities totaling $37.9 million in “Other liabilities, net” in our accompanying balance sheet, associated with our corporate office lease and various ground leases for which we are the lessee. The initial right-of-use assets comprised: (i) lease liabilities, (ii) $3.5 million of ground lease deferred rent payable reclassified from “Other liabilities, net" and (iii) $767,000 of identified net intangible assets and $140,000 of prepaid expenses both reclassified from “Other assets, net.” Further, effective January 1, 2019, any change to our assessment of whether previously recognized revenue is improbable of collection will be recognized as a deduction to revenue. Such amounts were recognized within “Property operating expense” prior to the adoption of Topic 842. Additionally, initial direct costs for both lessees and lessors is now limited to those costs that are incremental to the arrangement and would not have been incurred if the lease had not been obtained. As a result, we no longer capitalize internal leasing costs, which are now expensed as incurred within “Corporate and other - general and administrative costs.” Lessor Accounting Leases in which we are the lessor provide for the payment of fixed base rents payable monthly as well as reimbursements of real estate taxes, insurance and maintenance costs. We have elected a practical expedient which allows us to combine certain lease and non-lease components of our operating leases. Our non-lease components, which are not predominant within the contract, primarily relate to the reimbursement by our tenants of real estate taxes, insurance and maintenance costs, which vary each period, and are recognized together with fixed base rent in “Property rentals”, as variable lease income in the same periods as the related expenses are incurred. Certain commercial leases may also provide for the payment by the lessee of additional rents based on a percentage of sales, which are recorded as variable lease income in the period the additional rents are earned. The following is a summary of revenue from our non-cancellable leases included in the statements of operations: Three Months Ended March 31, 2019 (In thousands) Property rentals: Fixed $ 113,590 Variable 5,823 Total $ 119,413 As of March 31, 2019 , the undiscounted cash flows to be received from lease payments under our operating leases on an annual basis for the next five years and thereafter are as follows: Year ending December 31, Amount (In thousands) 2019 (1) $ 278,850 2020 323,967 2021 288,677 2022 258,016 2023 217,002 2024 194,847 Thereafter 1,048,678 ______________ (1) Amount is for the remainder of 2019. As of December 31, 2018 , under Topic 840, future base rental revenue under our non-cancellable operating leases is as follows: Year ending December 31, Amount (In thousands) 2019 $ 377,427 2020 321,205 2021 287,463 2022 256,352 2023 215,203 Thereafter 1,188,767 Lessee Accounting We are obligated under non-cancellable operating leases, including ground leases on certain of our properties through 2106 and our office leases. When a renewal option is included within the lease, we assess whether the option is reasonably certain of being exercised against relevant economic factors to determine whether or not the option period should be included as part of the lease term. Lease payments associated with renewal periods that we are reasonably certain will be exercised are included in the measurement of the corresponding lease liability and right-of-use asset. Rent expense for our operating leases is recognized on a straight-line basis over the expected lease term and is included in our statements of operations in either “Property operating expense” or “General and administrative expense: corporate and other” depending on the nature of the lease. Further, we are also obligated under a non-cancellable ground lease, which we classify as a finance lease. Since ownership of the land associated with our finance lease is reasonably certain to transfer to us upon the conclusion of the lease, we recorded $16.0 million to “Land and improvements” on our balance sheet when the lease commenced in 2017. Certain lease agreements include variable lease payments that, in the future, will vary based on changes in inflationary measures, market rates or our share of expenditures of the leased premises. We have elected the practical expedient not to separate lease and non-lease components for our ground and office leases. Our non-lease components primarily relate to property operating expenses associated with our office leases, which vary each period, and are recognized in rent expense when incurred. We discount our future lease payments for each lease to calculate the related lease liability using an estimated incremental borrowing rate computed based on observable corporate borrowing rates reflective of the general economic environment, taking into consideration our creditworthiness and various financing and asset specific considerations, adjusted to approximate a secured borrowing for the lease term. As of March 31, 2019 , the weighted average discount rate used in calculating lease liabilities for our active operating and finance leases were 5.2% and 5.8% , which have weighted average remaining lease terms of 20.1 and 7.8 years. As of March 31, 2019 , future minimum lease payments under our non-cancellable operating and finance leases are as follows: Year ending December 31, Operating Finance (In thousands) 2019 (1) $ 4,789 $ 791 2020 6,272 1,073 2021 6,201 1,095 2022 5,257 1,117 2023 2,000 1,139 2024 2,061 1,162 Thereafter 36,514 15,977 Total future minimum lease payments 63,094 22,354 Imputed interest (26,228 ) (6,683 ) Total (2) $ 36,866 $ 15,671 ______________ (1) Amounts are for the remainder of 2019. (2) The total for operating leases of $36.9 million corresponds to lease liabilities related to operating right-of-use assets and the total for finance leases of $15.7 million represents our finance lease liability, both of which are included in "Other liabilities, net" as of March 31, 2019 . See Note 8 for additional information. As of December 31, 2018 , under Topic 840, future minimum rental payments under our non-cancellable operating leases, capital leases and lease assumption liabilities are as follows: Year ending December 31, Amount (In thousands) 2019 $ 13,991 2020 13,710 2021 13,395 2022 12,554 2023 9,489 Thereafter 55,780 Total $ 118,919 For the three months ended March 31, 2019 , we incurred $663,000 of fixed operating and finance lease costs and $473,000 of variable operating lease costs.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2019
Leases [Abstract]
Operating Lease, Lease Income [Table Text Block]	As of March 31, 2019 , the undiscounted cash flows to be received from lease payments under our operating leases on an annual basis for the next five years and thereafter are as follows: Year ending December 31, Amount (In thousands) 2019 (1) $ 278,850 2020 323,967 2021 288,677 2022 258,016 2023 217,002 2024 194,847 Thereafter 1,048,678 The following is a summary of revenue from our non-cancellable leases included in the statements of operations: Three Months Ended March 31, 2019 (In thousands) Property rentals: Fixed $ 113,590 Variable 5,823 Total $ 119,413
Schedule of Future Minimum Lease Payments for Operating and Finance Leases [Table Text Block]	As of March 31, 2019 , future minimum lease payments under our non-cancellable operating and finance leases are as follows: Year ending December 31, Operating Finance (In thousands) 2019 (1) $ 4,789 $ 791 2020 6,272 1,073 2021 6,201 1,095 2022 5,257 1,117 2023 2,000 1,139 2024 2,061 1,162 Thereafter 36,514 15,977 Total future minimum lease payments 63,094 22,354 Imputed interest (26,228 ) (6,683 ) Total (2) $ 36,866 $ 15,671 ______________ (1) Amounts are for the remainder of 2019. (2) The total for operating leases of $36.9 million corresponds to lease liabilities related to operating right-of-use assets and the total for finance leases of $15.7 million represents our finance lease liability, both of which are included in "Other liabilities, net" as of March 31, 2019 . See Note 8 for additional information.
Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block]	As of December 31, 2018 , under Topic 840, future base rental revenue under our non-cancellable operating leases is as follows: Year ending December 31, Amount (In thousands) 2019 $ 377,427 2020 321,205 2021 287,463 2022 256,352 2023 215,203 Thereafter 1,188,767
Schedule of Future Minimum Lease Payments for Capital and Operating Leases [Table Text Block]	As of December 31, 2018 , under Topic 840, future minimum rental payments under our non-cancellable operating leases, capital leases and lease assumption liabilities are as follows: Year ending December 31, Amount (In thousands) 2019 $ 13,991 2020 13,710 2021 13,395 2022 12,554 2023 9,489 Thereafter 55,780 Total $ 118,919

Acquisitions, Disposals and A_2

Acquisitions, Disposals and Assets Held for Sale (Tables)	3 Months Ended
	Mar. 31, 2019
Discontinued Operations and Disposal Groups [Abstract]
Disclosure of Long Lived Assets Held-for-sale [Table Text Block]	The following is a summary of assets held for sale: Assets Segment Location Total Square Feet Assets Held for Sale Liabilities Related to Assets Held for Sale (In thousands) March 31, 2019 Pen Place (1) Other National Landing, Virginia — $ 73,949 $ 205 Mets 6, 7 and 8 (1) Other National Landing, Virginia — 94,509 281 — $ 168,458 $ 486 December 31, 2018 Commerce Executive / Commerce Metro Land (2) Commercial Reston, Virginia 388,562 $ 78,981 $ 3,717 _______________ (1) In March 2019, we entered into agreements for the sale of Pen Place and Mets 6, 7 and 8, future development assets having an aggregate estimated potential development density of up to approximately 4.1 million square feet, for approximately $293.9 million , subject to customary closing conditions. (2) As noted above, we sold Commerce Executive/Commerce Metro Land in February 2019 .
Disposal Groups, Including Discontinued Operations [Table Text Block]	The following is a summary of disposition activity for the three months ended March 31, 2019 : Date Disposed Assets Segment Location Total Square Feet Gross Sales Price Cash Proceeds from Sale Gain on Sale of Real Estate (In thousands) February 4, 2019 Commerce Executive / Commerce Metro Land (1) (2) Commercial / Other Reston, Virginia 388,562 $ 114,950 $ 117,676 $ 39,033 ______________ (1) The sale also included approximately 894,000 square feet of estimated potential development density. The sale was part of a reverse 1031 like-kind exchange. See Note 5 for additional information. (2) Cash proceeds include the reimbursement of $4.0 million of tenant improvement costs and leasing commissions paid by us prior to the closing.

Investments in and Advances t_2

Investments in and Advances to Unconsolidated Real Estate Ventures (Tables)	3 Months Ended
	Mar. 31, 2019
Equity Method Investments and Joint Ventures [Abstract]
Composition of Investments	The following is a summary of the debt of our unconsolidated real estate ventures: Weighted Average Effective (1) March 31, 2019 December 31, 2018 (In thousands) Variable rate (2) 5.00% $ 616,938 $ 461,704 Fixed rate (3) 3.93% 522,794 665,662 Unconsolidated real estate ventures - mortgages payable 1,139,732 1,127,366 Unamortized deferred financing costs (1,858 ) (1,998 ) Unconsolidated real estate ventures - mortgages payable, net (4) $ 1,137,874 $ 1,125,368 ______________ (1) Weighted average effective interest rate as of March 31, 2019 . (2) Includes variable rate mortgages payable with interest rate cap agreements. (3) Includes variable rate mortgages payable with interest rates fixed by interest rate swap agreements. (4) See Note 15 for additional information on guarantees of the debt of certain of our unconsolidated real estate ventures. The following is a summary of the financial information for our unconsolidated real estate ventures: March 31, 2019 December 31, 2018 Combined balance sheet information: (In thousands) Real estate, net $ 2,074,762 $ 2,050,985 Other assets, net (1) 191,210 169,264 Total assets $ 2,265,972 $ 2,220,249 Borrowings, net $ 1,137,874 $ 1,125,368 Other liabilities, net (1) 137,414 94,845 Total liabilities 1,275,288 1,220,213 Total equity 990,684 1,000,036 Total liabilities and equity $ 2,265,972 $ 2,220,249 ______________ (1) On January 1, 2019, our unconsolidated real estate ventures adopted Topic 842, which required us to record operating right-of-use assets totaling $52.4 million and related lease liabilities totaling $44.1 million . Three Months Ended March 31, 2019 2018 Combined income statement information: (In thousands) Total revenue $ 59,991 $ 73,173 Operating (loss) income (433 ) 4,374 Net loss (15,227 ) (4,675 ) The following is a summary of the composition of our investments in and advances to unconsolidated real estate ventures: Real Estate Venture Partners Ownership Interest (1) March 31, 2019 December 31, 2018 (In thousands) CPPIB 55.0% - 63.7% $ 98,292 $ 97,521 Landmark 1.8% - 49.0% 82,149 84,320 CBREI Venture 5.0% - 64.0% 72,689 73,776 Berkshire Group 50.0% 45,227 43,937 Brandywine 30.0% 13,880 13,777 CIM Group and Pacific Life Insurance Company 16.7% 8,829 9,339 Other 220 128 Total investments in unconsolidated real estate ventures 321,286 322,798 Advances to unconsolidated real estate ventures 80 80 Total investments in and advances to unconsolidated real estate ventures $ 321,366 $ 322,878 _______________ (1) Ownership interests as of March 31, 2019 . We have multiple investments with certain venture partners with varying ownership interests.

Other Assets, Net (Tables)

Other Assets, Net (Tables)	3 Months Ended
	Mar. 31, 2019
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Summary of Other Assets, Net	The following is a summary of other assets, net: March 31, 2019 December 31, 2018 (In thousands) Deferred leasing costs $ 210,565 $ 202,066 Accumulated amortization (74,217 ) (72,465 ) Deferred leasing costs, net 136,348 129,601 Other identified intangible assets, net 53,650 55,469 Lease intangible assets, net 31,319 34,390 Operating right-of-use assets, net (1) 34,151 — Prepaid expenses 5,386 6,482 Deferred financing costs on credit facility, net 4,316 4,806 Deposits 11,109 3,633 Derivative agreements, at fair value 1,894 10,383 Other 19,352 20,230 Total other assets, net $ 297,525 $ 264,994

Debt (Tables)

Debt (Tables)	3 Months Ended
	Mar. 31, 2019
Debt Disclosure [Abstract]
Summary of Debt	The following is a summary of amounts outstanding under the credit facility: Interest Rate (1) March 31, 2019 December 31, 2018 (In thousands) Revolving credit facility (2) (3) (4) 3.59% $ — $ — Tranche A-1 Term Loan (5) 3.32% $ 100,000 $ 100,000 Tranche A-2 Term Loan (5) 4.39% 200,000 200,000 Unsecured term loans 300,000 300,000 Unamortized deferred financing costs, net (2,723 ) (2,871 ) Unsecured term loans, net $ 297,277 $ 297,129 __________________________ (1) Interest rate as of March 31, 2019 . (2) As of March 31, 2019 and December 31, 2018 , letters of credit with an aggregate face amount of $5.8 million and $5.7 million were provided under our revolving credit facility. (3) As of March 31, 2019 and December 31, 2018 , net deferred financing costs related to our revolving credit facility totaling $4.3 million and $4.8 million were included in "Other assets, net." (4) The interest rate for the revolving credit facility excludes a 0.15% facility fee The following is a summary of mortgages payable: Weighted Average (1) March 31, 2019 December 31, 2018 (In thousands) Variable rate (2) 4.22% $ 415,898 $ 308,918 Fixed rate (3) 3.92% 1,425,688 1,535,734 Mortgages payable 1,841,586 1,844,652 Unamortized deferred financing costs and premium/ discount, net (5,744 ) (6,271 ) Mortgages payable, net $ 1,835,842 $ 1,838,381 __________________________ (1) Weighted average effective interest rate as of March 31, 2019 . (2) Includes variable rate mortgages payable with interest rate cap agreements. (3) Includes variable rate mortgages payable with interest rates fixed by interest rate swap agreements.

Other Liabilities, Net (Tables)

Other Liabilities, Net (Tables)	3 Months Ended
	Mar. 31, 2019
Other Liabilities Disclosure [Abstract]
Composition of Other Liabilities, Net	The following is a summary of other liabilities, net: March 31, 2019 December 31, 2018 (In thousands) Lease intangible liabilities $ 40,179 $ 40,179 Accumulated amortization (26,628 ) (26,081 ) Lease intangible liabilities, net 13,551 14,098 Prepaid rent 20,345 21,998 Lease assumption liabilities 24,771 23,105 Lease incentive liabilities 17,528 9,317 Lease liabilities related to operating right-of-use assets (1) 36,866 — Finance lease liability 15,671 15,704 Security deposits 17,505 17,696 Environmental liabilities 17,898 17,898 Ground lease deferred rent payable (2) — 3,510 Net deferred tax liability 6,012 6,878 Dividends payable — 45,193 Other 4,287 6,209 Total other liabilities, net $ 174,434 $ 181,606

Redeemable Noncontrolling Int_2

Redeemable Noncontrolling Interests (Tables)	3 Months Ended
	Mar. 31, 2019
Noncontrolling Interest [Abstract]
Redeemable Noncontrolling Interests	Below is a summary of the activity of redeemable noncontrolling interests: Three Months Ended March 31, 2019 2018 JBG SMITH LP Consolidated Real Estate Venture Total JBG SMITH LP Consolidated Real Estate Venture Total (In thousands) Balance as of beginning of period $ 552,159 $ 5,981 $ 558,140 $ 603,717 $ 5,412 $ 609,129 OP Unit redemptions (57,001 ) — (57,001 ) — — — Long-term incentive partnership units ("LTIP Units") issued in lieu of cash bonuses (1) 3,135 — 3,135 — — — Net income (loss) attributable to redeemable noncontrolling interests 3,386 1 3,387 (592 ) (2 ) (594 ) Other comprehensive income (1,383 ) — (1,383 ) 1,876 — 1,876 Share-based compensation expense 16,273 — 16,273 12,942 — 12,942 Adjustment to redemption value 62,212 — 62,212 (17,849 ) — (17,849 ) Balance as of end of period $ 578,781 $ 5,982 $ 584,763 $ 600,094 $ 5,410 $ 605,504

Share-Based Payments (Tables)

Share-Based Payments (Tables)	3 Months Ended
	Mar. 31, 2019
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Disclosure of Share-based Compensation Arrangements by Share-based Payment Award [Table Text Block]	The significant assumptions used to value LTIP and Time-Based LTIP Units included: Expected volatility 22.0% to 24.0% Risk-free interest rate 2.6 % Post-grant restriction periods 2 years The significant assumptions used to value the Performance-Based LTIP Units included: Expected volatility 22.0% to 23.0% Dividend yield 2.4% to 2.5% Risk-free interest rate 2.5% to 2.6%
Summary of Share-Based Compensation Expense	Share-based compensation expense is summarized as follows: Three Months Ended March 31, 2019 2018 (In thousands) Time-Based LTIP Units $ 2,934 $ 2,357 Performance-Based LTIP Units 2,208 1,157 Other equity awards (1) 1,059 784 Share-based compensation expense - other 6,201 4,298 Formation Awards 1,660 1,578 OP Units (2) 7,931 7,781 LTIP Units (2) 108 69 Special Performance-Based LTIP Units 644 — Special Time-Based LTIP Units 788 — Share-based compensation related to Formation Transaction and special equity awards (3) 11,131 9,428 Total share-based compensation expense 17,332 13,726 Less amount capitalized (743 ) (627 ) Share-based compensation expense $ 16,589 $ 13,099 ______________________________________________ (1) Includes compensation expense for certain executives who have elected to receive all or a portion of any cash bonus that may be paid in future periods related to past service in the form of fully vested LTIP Units and expense related to our employee share purchase plan. (2) Represents share-based compensation expense for LTIP Units and OP Units subject to post-Combination employment obligations. (3) Included in "General and administrative expense: Share-based compensation related to Formation Transaction and special equity awards" in the accompanying statements of operations.

Interest Expense Interest Exp_2

Interest Expense Interest Expense (Tables)	3 Months Ended
	Mar. 31, 2019
Interest Expense [Abstract]
Interest Income and Interest Expense Disclosure [Table Text Block]	The following is a summary of interest expense included in the statements of operations: Three Months Ended March 31, 2019 2018 (In thousands) Interest expense $ 22,877 $ 23,675 Amortization of deferred financing costs 1,164 1,217 Net unrealized loss (gain) on derivative financial instruments 48 (1,119 ) Capitalized interest (6,915 ) (4,516 ) Interest expense $ 17,174 $ 19,257

Earnings (Loss) Per Common Sh_2

Earnings (Loss) Per Common Share EPS (Tables)	3 Months Ended
	Mar. 31, 2019
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]	The following summarizes the calculation of basic and diluted earnings (loss) per common share and provides a reconciliation of the amounts of net income (loss) attributable to common shareholders used in calculating basic and diluted earnings (loss) per common share: Three Months Ended March 31, 2019 2018 (In thousands, except per share amounts) Net income (loss) $ 28,248 $ (4,786 ) Net (income) loss attributable to redeemable noncontrolling (3,387 ) 594 Net loss attributable to noncontrolling interests — 2 Net income (loss) attributable to common shareholders $ 24,861 $ (4,190 ) Weighted average number of common shares outstanding — basic 122,573 117,955 Effect of dilutive securities 850 — Weighted average number of common shares outstanding — diluted 123,423 117,955 Earnings (loss) per common share: Basic $ 0.20 $ (0.04 ) Diluted $ 0.20 $ (0.04 )

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2019
Fair Value Disclosures [Abstract]
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	The following are assets and liabilities measured at fair value on a recurring basis: Fair Value Measurements Total Level 1 Level 2 Level 3 March 31, 2019 (In thousands) Derivative financial instruments designated as cash flow hedges: Classified as assets in "Other assets, net" $ 1,892 $ — $ 1,892 $ — Classified as liabilities in "Other liabilities, net" 4,099 — 4,099 — Derivative financial instruments not designated as cash flow hedges: Classified as assets in "Other assets, net" 2 — 2 — December 31, 2018 Derivative financial instruments designated as cash flow hedges: Classified as assets in "Other assets, net" $ 7,913 $ — $ 7,913 $ — Classified as liabilities in "Other liabilities, net" 1,723 — 1,723 — Derivative financial instruments not designated as cash flow hedges: Classified as assets in "Other assets, net" 2,470 — 2,470 —
Schedule of Financial Instruments and Liabilities as Reflected on Balance Sheet	As of March 31, 2019 and December 31, 2018 , all financial instruments and liabilities were reflected in our balance sheets at amounts which, in our estimation, reasonably approximated their fair values, except for the following: March 31, 2019 December 31, 2018 Carrying Amount (1) Fair Value Carrying Amount (1) Fair Value (In thousands) Financial liabilities: Mortgages payable $ 1,841,586 $ 1,873,323 $ 1,844,652 $ 1,870,078 Unsecured term loans 300,000 304,583 300,000 300,727 ______________________________________ ( 1) The carrying amount consists of principal only

Segment Information (Tables)

Segment Information (Tables)	3 Months Ended
	Mar. 31, 2019
Segment Reporting [Abstract]
Segment information	The following table reflects the reconciliation of net income (loss) attributable to common shareholders to consolidated NOI: Three Months Ended March 31, 2019 2018 (In thousands) Net income (loss) attributable to common shareholders $ 24,861 $ (4,190 ) Add: Depreciation and amortization expense 48,719 49,160 General and administrative expense: Corporate and other 12,314 8,414 Third-party real estate services 28,066 22,609 Share-based compensation related to Formation Transaction and 11,131 9,428 Transaction and other costs 4,895 4,221 Interest expense 17,174 19,257 Income tax benefit (1,172 ) (908 ) Net income (loss) attributable to redeemable noncontrolling interests 3,387 (594 ) Less: Third-party real estate services, including reimbursements 27,691 24,330 Other income (excluding parking income of $6,455 and $6,363 in 2019 and 2018) 1,640 1,116 Income (loss) from unconsolidated real estate ventures, net 3,601 (1,902 ) Interest and other income, net 951 573 Gain on sale of real estate 39,033 455 Net loss attributable to noncontrolling interests — 2 Consolidated NOI $ 76,459 $ 82,823 Below is a summary of NOI by segment. Items classified in the Other column include future development assets, corporate entities and the elimination of intersegment activity. Three Months Ended March 31, 2019 Commercial Multifamily Other Total (In thousands) Property rentals revenue $ 96,247 $ 28,249 $ (5,083 ) $ 119,413 Other property operating income 6,375 80 — 6,455 Total property revenue 102,622 28,329 (5,083 ) 125,868 Property expense: — Property operating 30,481 7,967 (6,274 ) 32,174 Real estate taxes 12,513 3,548 1,174 17,235 Total property expense 42,994 11,515 (5,100 ) 49,409 Consolidated NOI $ 59,628 $ 16,814 $ 17 $ 76,459 Three Months Ended March 31, 2018 Commercial Multifamily Other Total (In thousands) Property rentals revenue $ 105,564 $ 25,837 $ (173 ) $ 131,228 Other property operating income 6,244 90 29 6,363 Total property revenue 111,808 25,927 (144 ) 137,591 Property expense: Property operating 25,837 7,287 2,034 35,158 Real estate taxes 14,781 3,547 1,282 19,610 Total property expense 40,618 10,834 3,316 54,768 Consolidated NOI $ 71,190 $ 15,093 $ (3,460 ) $ 82,823 The following is a summary of certain balance sheet data by segment: Commercial Multifamily Other Total March 31, 2019 (In thousands) Real estate, at cost $ 3,650,134 $ 1,702,845 $ 343,912 $ 5,696,891 Investments in and advances to unconsolidated real estate ventures 175,511 109,850 36,005 321,366 Total assets (1) 3,695,905 1,571,388 757,401 6,024,694 December 31, 2018 Real estate, at cost $ 3,634,472 $ 1,656,974 $ 501,288 $ 5,792,734 Investments in and advances to unconsolidated real estate ventures 177,173 109,232 36,473 322,878 Total assets (1) 3,707,255 1,528,177 761,853 5,997,285 __________________________ (1) Includes assets held for sale. See Note 3 for additional information.

Organization and Basis of Pre_3

Organization and Basis of Presentation - Narrative (Details)	3 Months Ended
	Mar. 31, 2019USD ($)ft²building_unitproperties	Mar. 31, 2018USD ($)
Real Estate Properties [Line Items]
Number of Real Estate Properties | properties	61
Parking Income | $	$ 6,455	$ 6,363
Cost of Other Property Operating Expense | $	$ 32,174,000	35,158,000
Asset under Construction
Real Estate Properties [Line Items]
Number of Real Estate Properties | properties	9
Future Development
Real Estate Properties [Line Items]
Number of Real Estate Properties | properties	40
Area of real estate property (in square feet) | ft²	22,100,000
Commercial Real Estate [Member]
Real Estate Properties [Line Items]
Number of Real Estate Properties | properties	45
Area of real estate property (in square feet) | ft²	12,500,000
Commercial Real Estate [Member] | Asset under Construction
Real Estate Properties [Line Items]
Number of Real Estate Properties | 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 | 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 | 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	18,700,000
Wholly Owned Properties | Commercial Real Estate [Member]
Real Estate Properties [Line Items]
Area of real estate property (in square feet) | ft²	10,900,000
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	89.00%
Restatement Adjustment [Member]
Real Estate Properties [Line Items]
Parking Income | $		6,400,000
Reimbursements from Tenants | $		10,900,000
Cost of Other Property Operating Expense | $		$ 4,300,000

Summary of Significant Accoun_4

Summary of Significant Accounting Policies Narratives (Details) - USD ($)	3 Months Ended
	Mar. 31, 2019	Jan. 01, 2019	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017
Leases [Abstract]
Land and Land Improvements					$ 16,000,000
Operating Lease, Weighted Average Discount Rate, Percent	5.20%
Operating right-of-use assets, net (1)	$ 34,151,000	$ 35,318,000	$ 0	$ 0
Lease liabilities related to operating right-of-use assets (1)	36,866,000	37,922,000	0	$ 0
Ground lease deferred rent payable	0	3,500,000	3,510,000
Other identified intangible assets, net	53,650,000	767,000	55,469,000
Prepaid expenses	$ 5,386,000	$ 140,000	$ 6,482,000
Finance Lease, Weighted Average Discount Rate, Percent	5.80%
Operating Lease, Weighted Average Remaining Lease Term	20 years 1 month
Finance Lease, Weighted Average Remaining Lease Term	7 years 9 months
Fixed operating and finance lease costs	$ 663,000
Variable operating lease costs	$ 473,000

Summary of Significant Accoun_5

Summary of Significant Accounting Policies Property Rentals (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019USD ($)
Leases [Abstract]
Property rentals - fixed	$ 113,590
Property rentals - variable	5,823
Property rentals - total	$ 119,413

Summary of Significant Accoun_6

Summary of Significant Accounting Policies Operating Lease, Payments to be Recevied (Details) $ in Thousands	Mar. 31, 2019USD ($)
Lessor, Lease, Description [Line Items]
2019	$ 278,850
2020	323,967
2021	288,677
2022	258,016
2023	217,002
2024	194,847
Thereafter	$ 1,048,678

Summary of Significant Accoun_7

Summary of Significant Accounting Policies Future Minimum Payments Receivable (Details) $ in Thousands	Dec. 31, 2018USD ($)
2019	$ 377,427
2020	321,205
2021	287,463
2022	256,352
2023	215,203
Thereafter	$ 1,188,767

Summary of Significant Accoun_8

Summary of Significant Accounting Policies Lessee, Lease Liability, Maturity (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Jan. 01, 2019	Dec. 31, 2018	Mar. 31, 2018
Operating Leases [Line Items]
2019 (1)	$ 4,789
2020	6,272
2021	6,201
2022	5,257
2023	2,000
2024	2,061
Thereafter	36,514
Total future minimum lease payments	63,094
Imputed interest	(26,228)
Lease liabilities related to operating right-of-use assets (1)	36,866	$ 37,922	$ 0	$ 0
2019	791
2020	1,073
2021	1,095
2022	1,117
2023	1,139
2024	1,162
Thereafter	15,977
Total future minimum lease payments	22,354
Imputed interest	(6,683)
Finance Lease, Liability	$ 15,671

Summary of Significant Accoun_9

Summary of Significant Accounting Policies Future Minimum Rental Payments (Details) $ in Thousands	Dec. 31, 2018USD ($)
Leases [Abstract]
2019	$ 13,991
2020	13,710
2021	13,395
2022	12,554
2023	9,489
Thereafter	55,780
Total	$ 118,919

Acquisitions, Disposals and A_3

Acquisitions, Disposals and Assets Held for Sale Dispositions and Assets Held for Sale (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019USD ($)ft²	Mar. 31, 2018USD ($)	Dec. 31, 2018USD ($)ft²
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain on sale of real estate	$ 39,033	$ 455
Assets held for sale	168,458		$ 78,981
Liabilities related to assets held for sale	486		$ 3,717
National Landing, Virginia [Member] | Pen Place - Land Parcel [Member] | Other
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Assets held for sale	73,949
Liabilities related to assets held for sale	205
National Landing, Virginia [Member] | Mets 6, 7 and 8 [Member] | Other
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Assets held for sale	94,509
Liabilities related to assets held for sale	281
National Landing, Virginia [Member] | Penn Place and Met 6, 7 and 8 [Member] | Other
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from Sale of Property Held-for-sale	$ 293,900
Reston, Virginia [Member] | Commerce Executive/Commerce Metro Land [Member] | Commercial Segment [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Area of real estate property (in square feet) | ft²	388,562		388,562
Proceeds from Sale of Property Held-for-sale	$ 114,950
Proceeds from sale of real estate	117,676
Gain on sale of real estate	39,033
Assets held for sale			$ 78,981
Liabilities related to assets held for sale			$ 3,717
Proceeds from Sale of Real Estate Held-for-Investment, Reimbursements	$ 4,000
Future Development
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Area of real estate property (in square feet) | ft²	22,100,000
Future Development | Commerce Executive/Commerce Metro Land [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Area of real estate property (in square feet) | ft²	894,000
Future Development | Penn Place and Met 6, 7 and 8 [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Area of real estate property (in square feet) | ft²	4,100,000

Investments in and Advances t_3

Investments in and Advances to Unconsolidated Real Estate Ventures - Summary of Composition of Investments (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Schedule of Equity Method Investments [Line Items]
Total investments in unconsolidated real estate ventures	$ 321,286	$ 322,798
Advances to unconsolidated real estate ventures	80	80
Total investments in and advances to unconsolidated real estate ventures	321,366	322,878
Canadian Pension Plan Investment Board (CPPIB)
Schedule of Equity Method Investments [Line Items]
Total investments in unconsolidated real estate ventures	98,292	97,521
Landmark
Schedule of Equity Method Investments [Line Items]
Total investments in unconsolidated real estate ventures	82,149	84,320
CBREI Venture
Schedule of Equity Method Investments [Line Items]
Total investments in unconsolidated real estate ventures	$ 72,689	73,776
Berkshire Group
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	50.00%
Total investments in unconsolidated real estate ventures	$ 45,227	43,937
Brandywine
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	30.00%
Total investments in unconsolidated real estate ventures	$ 13,880	13,777
CIM/PacLife
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	16.70%
Total investments in unconsolidated real estate ventures	$ 8,829	9,339
Other
Schedule of Equity Method Investments [Line Items]
Total investments in unconsolidated real estate ventures	$ 220	$ 128
Minimum | Canadian Pension Plan Investment Board (CPPIB)
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	55.00%
Minimum | Landmark
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	1.80%
Minimum | CBREI Venture
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	5.00%
Maximum | Canadian Pension Plan Investment Board (CPPIB)
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	63.70%
Maximum | Landmark
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	49.00%
Maximum | CBREI Venture
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	64.00%

Investments in and Advances t_4

Investments in and Advances to Unconsolidated Real Estate Ventures - Narrative (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended
	Feb. 28, 2018	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Schedule of Equity Method Investments [Line Items]
Deconsolidation of 1900 N Street		$ 0	$ 95,923
Real Estate Investments, Unconsolidated Real Estate and Other Joint Ventures, Excluding Advances		321,286		$ 322,798
Income (Loss) from Equity Method Investments		3,601	$ (1,902)
Canadian Pension Plan Investment Board (CPPIB)
Schedule of Equity Method Investments [Line Items]
Real Estate Investments, Unconsolidated Real Estate and Other Joint Ventures, Excluding Advances		98,292		$ 97,521
1900 N Street
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	100.00%
Equity Method Investment, Ownership Percentage After Funding Of Contributions	55.00%
1101 17th Street [Member]
Schedule of Equity Method Investments [Line Items]
Real Estate Investments, Unconsolidated Real Estate and Other Joint Ventures, Excluding Advances		0
Income (Loss) from Equity Method Investments		$ 6,400
Canadian Pension Plan Investment Board (CPPIB) | 1900 N Street
Schedule of Equity Method Investments [Line Items]
Long-term Purchase Commitment, Amount	$ 101,300
Equity Method Investment, Ownership Percentage	45.00%

Investments in and Advances t_5

Investments in and Advances to Unconsolidated Real Estate Ventures - Summary of Debt (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Equity Method Investments and Joint Ventures [Abstract]
Variable rate, weighted average interest rate	5.00%
Variable rate	$ 616,938	$ 461,704
Fixed rate, weighted average interest rate	3.93%
Fixed rate	$ 522,794	665,662
Unconsolidated real estate ventures - mortgages payable	1,139,732	1,127,366
Unamortized deferred financing costs	(1,858)	(1,998)
Unconsolidated real estate ventures - mortgages payable, net	$ 1,137,874	$ 1,125,368

Investments in and Advances t_6

Investments in and Advances to Unconsolidated Real Estate Ventures - Condensed Combined Financial Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Jan. 01, 2019	Dec. 31, 2018
Equity Method Investment, Summarized Financial Information, Assets, Operating Leases, Right of Use Assets			$ 52,400
Operating Lease, Liability			$ 44,100
Combined balance sheet information:
Real estate, net	$ 2,074,762			$ 2,050,985
Other assets, net	191,210			169,264
Total assets	2,265,972			2,220,249
Mortgages payable, net	1,137,874			1,125,368
Other liabilities, net	137,414			94,845
Total liabilities	1,275,288			1,220,213
Total equity	990,684			1,000,036
Total liabilities and equity	2,265,972			$ 2,220,249
Combined income statement information:
Total revenue	59,991	$ 73,173
Operating income	(433)	4,374
Net loss	$ (15,227)	$ (4,675)

Variable Interest Entities (Det

Variable Interest Entities (Details) $ in Millions	Mar. 31, 2019USD ($)properties	Dec. 31, 2018USD ($)
Variable Interest Entity [Line Items]
Number of Real Estate Properties | properties	61
Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Assets	$ 224.7	$ 232.8
Variable Interest Entity, Primary Beneficiary
Variable Interest Entity [Line Items]
Assets	74.2	94.8
Liabilities	$ 11.9	$ 43.4
Number of Real Estate Properties	1	2

Other Assets, Net Summary of Ot

Other Assets, Net Summary of Other Assets, Net (Details) - USD ($)	Mar. 31, 2019	Jan. 01, 2019	Dec. 31, 2018	Mar. 31, 2018
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Deferred leasing costs	$ 210,565,000		$ 202,066,000
Accumulated amortization	(74,217,000)		(72,465,000)
Deferred leasing costs, net	136,348,000		129,601,000
Other identified intangible assets, net	53,650,000	$ 767,000	55,469,000
Lease intangible assets, net	31,319,000		34,390,000
Operating right-of-use assets, net (1)	34,151,000	35,318,000	0	$ 0
Prepaid expenses	5,386,000	$ 140,000	6,482,000
Deferred financing costs on credit facility, net	4,316,000		4,806,000
Deposits	11,109,000		3,633,000
Derivative agreements, at fair value	1,894,000		10,383,000
Other	19,352,000		20,230,000
Total other assets, net	$ 297,525,000		$ 264,994,000

Debt - Schedule of Mortgages Pa

Debt - Schedule of Mortgages Payable (Details) - Mortgages payable - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Variable interest rate	4.22%
Variable rate amount	$ 415,898	$ 308,918
Fixed interest rate	3.92%
Fixed rate amount	$ 1,425,688	1,535,734
Debt, gross	1,841,586	1,844,652
Unamortized deferred financing costs and premium/ discount, net	(5,744)	(6,271)
Debt, net	$ 1,835,842	$ 1,838,381

Debt - Narrative (Details)

Debt - Narrative (Details) $ in Millions	3 Months Ended
	Mar. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Mortgages payable
Line of Credit Facility [Line Items]
Net carrying value of real estate collateralizing the mortgages payable	$ 2,300	$ 2,300
Derivative, notional amount	1,200	$ 1,300
Line of credit
Line of Credit Facility [Line Items]
Credit facility, maximum borrowing capacity	1,400
Line of credit | Revolving credit facility
Line of Credit Facility [Line Items]
Credit facility, maximum borrowing capacity	$ 1,000
Debt Instrument, Number Of Term Extension Options	2
Debt Instrument, Extension Option, Term	6 months
Line of credit | Tranche A-1 Term Loan
Line of Credit Facility [Line Items]
Derivative, notional amount	$ 100
Credit facility, maximum borrowing capacity	200
Line of credit | Tranche A-2 Term Loan
Line of Credit Facility [Line Items]
Derivative, notional amount	64
Credit facility, maximum borrowing capacity	$ 200

Debt - Summary of Amounts Outst

Debt - Summary of Amounts Outstanding under the Credit Facility (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Line of Credit Facility [Line Items]
Debt Issuance Costs, Line of Credit Arrangements, Net	$ 4,316	$ 4,806
Tranche A-1 and A-2 Loans [Member]
Line of Credit Facility [Line Items]
Debt, gross	300,000	300,000
Unamortized deferred financing costs, net	(2,723)	(2,871)
Debt, net	$ 297,277	297,129
Line of credit | Revolving credit facility
Line of Credit Facility [Line Items]
Interest Rate (1)	3.59%
Debt, net	$ 0	0
Letters of Credit Outstanding, Amount	$ 5,800	5,700
Line of Credit Facility, Commitment Fee Percentage	0.15%
Line of credit | Tranche A-1 Term Loan
Line of Credit Facility [Line Items]
Interest Rate (1)	3.32%
Debt, gross	$ 100,000	100,000
Derivative, Notional Amount	$ 100,000
Line of credit | Tranche A-2 Term Loan
Line of Credit Facility [Line Items]
Interest Rate (1)	4.39%
Debt, gross	$ 200,000	$ 200,000
Derivative, Notional Amount	$ 64,000

Other Liabilities, Net Summary

Other Liabilities, Net Summary of Other Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Jan. 01, 2019	Dec. 31, 2018	Mar. 31, 2018
Schedule of Other Liabilities [Line Items]
Lease intangible liabilities	$ 40,179		$ 40,179
Accumulated amortization	(26,628)		(26,081)
Lease intangible liabilities, net	13,551		14,098
Prepaid rent	20,345		21,998
Lease assumption liabilities	24,771		23,105
Lease incentive liabilities	17,528		9,317
Lease liabilities related to operating right-of-use assets (1)	36,866	$ 37,922	0	$ 0
Finance Lease, Liability	15,671
Finance lease liability			15,704
Security deposits	17,505		17,696
Environmental liabilities	17,898		17,898
Ground lease deferred rent payable	0	$ 3,500	3,510
Net deferred tax liability	6,012		6,878
Dividends payable	0		45,193
Other	4,287		6,209
Total other liabilities, net	$ 174,434		$ 181,606

Redeemable Noncontrolling Int_3

Redeemable Noncontrolling Interests - Narrative (Details) shares in Millions	3 Months Ended
	Mar. 31, 2019shares
JBG Smith, LP
Noncontrolling Interest [Line Items]
Ownership interest by parent	89.00%
Consolidated Real Estate Venture
Noncontrolling Interest [Line Items]
Ownership interest by parent	90.20%
Ownership interest by parent, threshold for capital contributions to cease	97.00%
OP Units [Member]
Noncontrolling Interest [Line Items]
Common shares and OP Units issued in consideration	15.2
Conversion of common limited partnership units to common shares	1.7
OP Units [Member] | JBG Smith, LP
Noncontrolling Interest [Line Items]
Ownership interest by parent	11.00%
Minimum
Noncontrolling Interest [Line Items]
Redemption period	2 years
Maximum
Noncontrolling Interest [Line Items]
Redemption period	7 years

Redeemable Noncontrolling Int_4

Redeemable Noncontrolling Interests - Summary of the Activity of Redeemable Noncontrolling Interests (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Temporary Equity
Beginning Balance	$ 558,140	$ 609,129
Fair value of OP Unit redemptions	(57,001)	0
Long-term incentive partnership units (LTIP Units) issued in lieu of cash bonuses (1)	3,135	0
Net income (loss) attributable to redeemable noncontrolling interests	3,387	(594)
Other comprehensive income	(1,383)	1,876
Share-based compensation expense	16,273	12,942
Adjustment to redemption value	62,212	(17,849)
Ending Balance	584,763	605,504
JBG Smith, LP
Temporary Equity
Beginning Balance	552,159	603,717
Fair value of OP Unit redemptions	(57,001)	0
Long-term incentive partnership units (LTIP Units) issued in lieu of cash bonuses (1)	3,135	0
Net income (loss) attributable to redeemable noncontrolling interests	3,386	(592)
Other comprehensive income	(1,383)	1,876
Share-based compensation expense	16,273	12,942
Adjustment to redemption value	62,212	(17,849)
Ending Balance	578,781	600,094
Consolidated Real Estate Venture
Temporary Equity
Beginning Balance	5,981	5,412
Fair value of OP Unit redemptions	0	0
Long-term incentive partnership units (LTIP Units) issued in lieu of cash bonuses (1)	0	0
Net income (loss) attributable to redeemable noncontrolling interests	1	(2)
Other comprehensive income	0	0
Share-based compensation expense	0	0
Adjustment to redemption value	0	0
Ending Balance	$ 5,982	$ 5,410

Share-Based Payments - LTIP and

Share-Based Payments - LTIP and Time-Based LTIP Units (Details) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2019USD ($)$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Compensation expense recognition period (in years)	2 years 8 months
Management [Member] | Time-Based LTIP Units
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Equity grants (in shares) | shares	350,759
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights	P4Y
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage	25.00%
Compensation expense recognition period (in years)	4 years
Fair value of awards on grant date | $	$ 12
Weighted Average Grant-Date Fair Value
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value | $ / shares	$ 34.24
Management [Member] | LTIP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Equity grants (in shares) | shares	91,636
Fair value of awards on grant date | $	$ 3.1
Weighted Average Grant-Date Fair Value
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value | $ / shares	$ 34.21
Measurement Input, Price Volatility [Member] | LTIP and Time-Based LTIP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Minimum	22.00%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Maximum	24.00%
Measurement Input, Risk Free Interest Rate [Member] | LTIP and Time-Based LTIP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate, Minimum	2.60%
Measurement Input, Expected Term [Member] | LTIP and Time-Based LTIP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term	2 years

Share-Based Payments - Performa

Share-Based Payments - Performance-Based LTIP Units (Details) - Performance Shares [Member] $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2019USD ($)$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity grants (in shares) | shares	477,640
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	3 years
Fair value of awards on grant date | $	$ 9.3
Weighted Average Grant-Date Fair Value
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value | $ / shares	$ 19.49
Share-based Compensation Award, Tranche One [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage	50.00%
Share-based Compensation Award, Tranche One [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage	50.00%
Measurement Input, Price Volatility [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Minimum	22.00%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Maximum	23.00%
Measurement Input, Risk Free Interest Rate [Member]
Weighted Average Grant-Date Fair Value
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate, Minimum	2.50%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate, Maximum	2.60%
Minimum | Measurement Input, Expected Dividend Rate [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate	2.40%
Maximum | Measurement Input, Expected Dividend Rate [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate	2.50%

Share-Based Payments - Summary

Share-Based Payments - Summary of Share-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation related to Formation Transaction and special equity awards	$ 11,131	$ 9,428
Allocated Share-based Compensation Expense, Before Capitalization	17,332	13,726
Less amount capitalized	(743)	(627)
Share-based compensation expense	16,589	13,099
Total unrecognized compensation expense	$ 123,600
Compensation expense recognition period (in years)	2 years 8 months
Time-Based LTIP Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense	$ 2,934	2,357
Performance-Based LTIP Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense	$ 2,208	1,157
Compensation expense recognition period (in years)	4 years
Other Equity Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense	$ 1,059	784
Share-based compensation expense - other
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense	6,201	4,298
Formation Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense	1,660	1,578
OP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense	7,931	7,781
LTIP Units Related to Formation Transaction And Other [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense	108	69
Special Performance-Based LTIP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense	644	0
Special Time-Based LTIP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense	788	0
Share-based compensation related to Formation Transaction
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation related to Formation Transaction and special equity awards	$ 11,131	$ 9,428

Interest Expense Interest Exp_3

Interest Expense Interest Expense (Details) - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Interest expense	$ 22,877,000	$ 23,675,000
Amortization of deferred financing costs	1,164,000	1,217,000
Net unrealized loss (gain) on derivative financial instruments not designated as cash flow hedges	48,000	(1,119,000)
Capitalized interest	(6,915,000)	(4,516,000)
Interest Expense	$ 17,174,000	$ 19,257,000

Earnings (Loss) Per Common Sh_3

Earnings (Loss) Per Common Share - Schedule of Earnings (Loss) Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Earnings Per Share [Abstract]
Net income (loss)	$ 28,248	$ (4,786)
Net (income) loss attributable to redeemable noncontrolling interests	3,387	(594)
Net loss attributable to noncontrolling interests	0	(2)
Net income (loss) attributable to common shareholders	$ (24,861)	$ 4,190
Weighted average number of common shares outstanding — basic	122,573	117,955
Effect of dilutive securities	850	0
Weighted average number of common shares outstanding — diluted	123,423	117,955
Earnings (loss) per common share:
Earnings Per Share, Basic	$ 0.20	$ (0.04)
Earnings Per Share, Diluted	$ 0.20	$ (0.04)

Earnings (Loss) Per Common Sh_4

Earnings (Loss) Per Common Share - Narrative (Details) - shares shares in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	3.9	3.8

Earnings (Loss) Per Common Sh_5

Earnings (Loss) Per Common Share - Antidilutive Securities Excluded (Details) - shares shares in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	3.9	3.8

Fair Value Measurements - Narra

Fair Value Measurements - Narrative (Details) - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Net unrealized gain (loss) on derivative designated as cash flow hedge	$ (3,200,000)	$ 8,300,000
Gain expected to be reclassified into interest expense within the next 12 months	1,800,000
Net unrealized loss (gain) on derivative financial instruments not designated as cash flow hedges	$ 48,000	$ (1,119,000)

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis (Details) - Interest rate swap and caps - Recurring - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Other Assets, Net | Designated as Hedging Instrument
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Classified as assets in Other assets, net	$ 1,892	$ 7,913
Other Assets, Net | Designated as Hedging Instrument | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Classified as assets in Other assets, net	0	0
Other Assets, Net | Designated as Hedging Instrument | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Classified as assets in Other assets, net	1,892	7,913
Other Assets, Net | Designated as Hedging Instrument | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Classified as assets in Other assets, net	0	0
Other Assets, Net | Not Designated as Hedging Instrument
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Classified as assets in Other assets, net	2	2,470
Other Assets, Net | Not Designated as Hedging Instrument | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Classified as assets in Other assets, net	0	0
Other Assets, Net | Not Designated as Hedging Instrument | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Classified as assets in Other assets, net	2	2,470
Other Assets, Net | Not Designated as Hedging Instrument | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Classified as assets in Other assets, net	0	0
Other Liabilities, Net | Designated as Hedging Instrument
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Classified as liabilities in Other liabilities, net	4,099	1,723
Other Liabilities, Net | Designated as Hedging Instrument | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Classified as liabilities in Other liabilities, net	0	0
Other Liabilities, Net | Designated as Hedging Instrument | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Classified as liabilities in Other liabilities, net	4,099	1,723
Other Liabilities, Net | Designated as Hedging Instrument | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Classified as liabilities in Other liabilities, net	$ 0	$ 0

Fair Value Measurements - Finan

Fair Value Measurements - Financial Assets and Liabilities Not Measured at Fair Value (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Mortgages payable | Carrying Amount
Financial liabilities:
Financial liabilities	$ 1,841,586	$ 1,844,652
Mortgages payable | Fair Value
Financial liabilities:
Financial liabilities	1,873,323	1,870,078
Unsecured term loans | Carrying Amount
Financial liabilities:
Financial liabilities	300,000	300,000
Unsecured term loans | Fair Value
Financial liabilities:
Financial liabilities	$ 304,583	$ 300,727

Segment Information - Narrative

Segment Information - Narrative (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019USD ($)segment	Mar. 31, 2018segment	Dec. 31, 2018USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment	3	3
Other assets, net	$ 297,525		$ 264,994
Third-Party Real Estate Services Segment
Segment Reporting Information [Line Items]
Other assets, net	$ 36,800		$ 38,600

Segment Information - Schedule

Segment Information - Schedule of Reconciliation of Net Income Attributable to Parent (Details) - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Business Acquisition [Line Items]
Net income (loss) attributable to common shareholders	$ 24,861,000	$ (4,190,000)
Depreciation and amortization	48,719,000	49,160,000
Corporate and other	12,314,000	8,414,000
Third-party real estate services	28,066,000	22,609,000
Share-based compensation related to Formation Transaction and special equity awards	11,131,000	9,428,000
Transaction and other costs	4,895,000	4,221,000
Interest expense	17,174,000	19,257,000
Income tax benefit	(1,172,000)	(908,000)
Net (income) loss attributable to redeemable noncontrolling interests	3,387,000	(594,000)
Third-party real estate services, including reimbursements	27,691,000	24,330,000
Other Income, Excluding Parking Income	1,640,000	1,116,000
Income (loss) from unconsolidated real estate ventures, net	3,601,000	(1,902,000)
Interest and other income, net	951,000	573,000
Gain on sale of real estate	39,033,000	455,000
Net loss attributable to noncontrolling interests	0	2,000
Consolidated NOI	76,459,000	82,823,000
Parking Income	$ 6,455	$ 6,363

Segment Information - Summary o

Segment Information - Summary of NOI by Segment (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Segment Reporting Information [Line Items]
Property rentals	$ 119,413	$ 131,228
Property operating	32,174	35,158
Real estate taxes	17,235	19,610
Operating Segments
Segment Reporting Information [Line Items]
Property rentals	119,413	131,228
Other property operating income	6,455	6,363
Total rental revenue	125,868	137,591
Property operating	32,174	35,158
Real estate taxes	17,235	19,610
Total rental expense	49,409	54,768
Consolidated NOI	76,459	82,823
Operating Segments | Commercial Segment [Member]
Segment Reporting Information [Line Items]
Property rentals	96,247	105,564
Other property operating income	6,375	6,244
Total rental revenue	102,622	111,808
Property operating	30,481	25,837
Real estate taxes	12,513	14,781
Total rental expense	42,994	40,618
Consolidated NOI	59,628	71,190
Operating Segments | Multifamily
Segment Reporting Information [Line Items]
Property rentals	28,249	25,837
Other property operating income	80	90
Total rental revenue	28,329	25,927
Property operating	7,967	7,287
Real estate taxes	3,548	3,547
Total rental expense	11,515	10,834
Consolidated NOI	16,814	15,093
Operating Segments | Other
Segment Reporting Information [Line Items]
Property rentals	(5,083)	(173)
Other property operating income	0	29
Total rental revenue	(5,083)	(144)
Property operating	(6,274)	2,034
Real estate taxes	1,174	1,282
Total rental expense	(5,100)	3,316
Consolidated NOI	$ 17	$ (3,460)

Segment Information - Summary_2

Segment Information - Summary of Certain Balance Sheet Data by Segment (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Real estate, at cost	$ 5,696,891	$ 5,792,734
Investments in and advances to unconsolidated real estate ventures	321,366	322,878
Total assets (1)	6,024,694	5,997,285
Operating Segments | Commercial Segment [Member]
Segment Reporting Information [Line Items]
Real estate, at cost	3,650,134	3,634,472
Investments in and advances to unconsolidated real estate ventures	175,511	177,173
Total assets (1)	3,695,905	3,707,255
Operating Segments | Multifamily
Segment Reporting Information [Line Items]
Real estate, at cost	1,702,845	1,656,974
Investments in and advances to unconsolidated real estate ventures	109,850	109,232
Total assets (1)	1,571,388	1,528,177
Operating Segments | Other
Segment Reporting Information [Line Items]
Real estate, at cost	343,912	501,288
Investments in and advances to unconsolidated real estate ventures	36,005	36,473
Total assets (1)	$ 757,401	$ 761,853

Commitments and Contingencies -

Commitments and Contingencies - Narrative (Details) - USD ($)	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Real Estate Properties [Line Items]
General liability insurance limit	$ 200,000,000
Property and rental value insurance coverage limit	2,000,000,000
Terrorist acts insurance coverage limit	2,000,000,000
Purchase obligation	456,900,000
Environmental liabilities	17,898,000	$ 17,898,000
Additional capital funding committed amount	48,600,000
Consolidated Properties
Real Estate Properties [Line Items]
Purchase obligation	385,900,000
Principal payment guarantees	8,300,000
Unconsolidated Properties
Real Estate Properties [Line Items]
Purchase obligation	71,100,000
Principal payment guarantees	$ 0
Minimum
Real Estate Properties [Line Items]
Commitment amortization period	2 years
Maximum
Real Estate Properties [Line Items]
Commitment amortization period	3 years

Transactions with Vornado and_2

Transactions with Vornado and Related Parties (Details) - USD ($)	Jul. 18, 2017	Jul. 17, 2017	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Related Party Transaction [Line Items]
Third-party real estate services, including reimbursements			$ 27,691,000	$ 24,330,000
Corporate and other			12,314,000	8,414,000
Affiliated Entity [Member] | Legacy JBG Funds [Member]
Related Party Transaction [Line Items]
Corporate and other			1,200,000
Affiliated Entity [Member] | Separation and Combination transaction | Vornado Realty Trust [Member]
Related Party Transaction [Line Items]
Expenses from related parties			1,200,000
Revenue from related parties			488,000	600,000
Affiliated Entity [Member] | Supervisory Services of Properties [Member] | BMS
Related Party Transaction [Line Items]
Related party transaction amount			5,200,000	4,000,000
Affiliated Entity [Member] | Fees from Legacy JBG Funds | Legacy JBG Funds [Member]
Related Party Transaction [Line Items]
Third-party real estate services, including reimbursements			8,400,000	$ 8,600,000
Accounts Receivable, Related Parties			3,900,000		$ 3,600,000
Trustee | Consulting agreement
Related Party Transaction [Line Items]
Related party transaction, monthly amount		$ 169,400
Transaction services, initial period (in months)		24 months
JBG Companies [Member]
Related Party Transaction [Line Items]
Liability incurred in connection with the Combination	$ 4,100,000		$ 432,000

Subsequent Events (Details)

Subsequent Events (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	May 07, 2019	Apr. 30, 2019	Apr. 15, 2019	Mar. 31, 2019	Dec. 31, 2018
Subsequent Event [Line Items]
Common Stock, Shares, Issued				122,594	120,937
Subsequent Event [Member]
Subsequent Event [Line Items]
Common Stock, Shares, Issued			11,500
Excess Stock, Shares Issued			1,500
Shares Issued, Price Per Share			$ 42
Proceeds from Issuance of Common Stock		$ 472.3
Common Stock, Dividends, Per Share, Declared	$ 0.225
Mortgages [Member] | The Barlett and Fort Totten Square [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Repayments of Secured Debt		$ 293.6