JBG SMITH Properties (JBGS) 10-K 12 Mar 18 2017 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2017	Mar. 05, 2018	Jun. 30, 2017
Document And Entity Information [Abstract]
Entity Registrant Name	JBG SMITH PROPERTIES
Entity Central Index Key	1,689,796
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Document Type	10-K
Document Period End Date	Dec. 31, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Common Stock, Shares Outstanding		117,954,877
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 0

Consolidated and Combined Balan

Consolidated and Combined Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Real estate, at cost:
Land and improvements	$ 1,368,294	$ 939,592
Buildings and improvements	3,670,268	3,064,466
Construction in progress, including land	978,942	151,333
Real estate held for sale	8,293	0
Real estate, at cost	6,025,797	4,155,391
Less accumulated depreciation	(1,011,330)	(930,769)
Real estate, net	5,014,467	3,224,622
Cash and cash equivalents	316,676	29,000
Restricted cash	21,881	3,263
Tenant and other receivables, net	46,734	33,380
Deferred rent receivable, net	146,315	136,582
Investments in and advances to unconsolidated real estate ventures	261,811	45,776
Receivable from former parent	0	75,062
Other assets, net	263,923	112,955
TOTAL ASSETS	6,071,807	3,660,640
Liabilities:
Mortgages payable, net	2,025,692	1,165,014
Revolving credit facility	115,751	0
Unsecured term loan, net	46,537	0
Payable to former parent	0	283,232
Accounts payable and accrued expenses	138,607	40,923
Other liabilities, net	161,277	49,487
Total liabilities	2,487,864	1,538,656
Commitments and Contingencies
Redeemable noncontrolling interests	609,129	0
Shareholders' equity:
Preferred shares, $0.01 par value - 200,000 shares authorized, none issued	0
Common shares, $0.01 par value - 500,000 shares authorized and 117,955 shares issued and outstanding at December 31, 2017	1,180
Additional paid-in capital	3,063,625
Accumulated deficit	(95,809)
Accumulated other comprehensive income	1,612
Shareholders' equity / Former parent equity	2,970,608	2,121,689
Noncontrolling interests in consolidated subsidiaries	4,206	295
Total equity	2,974,814	2,121,984
TOTAL LIABILITIES, REDEEMABLE NONCONTROLLING INTERESTS AND EQUITY	$ 6,071,807	$ 3,660,640

Consolidated and Combined Bala3

Consolidated and Combined Balance Sheets (Parenthetical)	Dec. 31, 2017$ / sharesshares
Statement of Financial Position [Abstract]
Preferred shares, par value (in dollars per share) | $ / shares	$ 0.01
Preferred shares, shares authorized	200,000,000
Preferred shares, shares issued	0
Preferred shares, shares outstanding	0
Common shares, par value (in dollars per share) | $ / shares	$ 0.01
Common shares, shares authorized	500,000,000
Common shares, shares issued	117,955,000
Common shares, shares outstanding	117,955,000

Consolidated and Combined State

Consolidated and Combined Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
REVENUE
Property rentals	$ 436,625	$ 401,595	$ 389,810
Tenant reimbursements	37,985	37,661	40,476
Third-party real estate services, including reimbursements	63,236	33,882	29,467
Other income	5,167	5,381	10,854
Total revenue	543,013	478,519	470,607
EXPENSES
Depreciation and amortization	161,659	133,343	144,984
Property operating	111,055	100,304	101,511
Real estate taxes	66,434	57,784	58,874
General and administrative:
Corporate and other	47,131	48,753	44,424
Third-party real estate services	51,919	19,066	18,217
Share-based compensation related to Formation Transaction	29,251	0	0
Transaction and other costs	127,739	6,476	0
Total operating expenses	595,188	365,726	368,010
OPERATING INCOME (LOSS)	(52,175)	112,793	102,597
Loss from unconsolidated real estate ventures, net	(4,143)	(947)	(4,283)
Interest and other income, net	1,788	2,992	2,557
Interest expense	(58,141)	(51,781)	(50,823)
Loss on extinguishment of debt	(701)	0	0
Gain on bargain purchase	24,376	0	0
INCOME (LOSS) BEFORE INCOME TAX BENEFIT (EXPENSE)	(88,996)	63,057	50,048
Income tax benefit (expense)	9,912	(1,083)	(420)
NET INCOME (LOSS)	(79,084)	61,974	49,628
Net loss attributable to redeemable noncontrolling interests	7,328	0	0
Net loss attributable to noncontrolling interest	3	0	0
NET INCOME (LOSS) ATTRIBUTABLE TO COMMON SHAREHOLDERS	$ (71,753)	$ 61,974	$ 49,628
EARNINGS (LOSS) PER COMMON SHARE:
Basic (in dollars per share)	$ (0.70)	$ 0.62	$ 0.49
Diluted (in dollars per share)	$ (0.70)	$ 0.62	$ 0.49
WEIGHTED AVERAGE NUMBER OF COMMON SHARES OUTSTANDING - basic and diluted (in shares)	105,359	100,571	100,571
DIVIDENDS DECLARED PER COMMON SHARE (in dollars pre share)	$ 0.45	$ 0	$ 0

Consolidated and Combined Stat5

Consolidated and Combined Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Comprehensive Income [Abstract]
NET INCOME (LOSS)	$ (79,084)	$ 61,974	$ 49,628
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Change in fair value of derivative financial instruments	1,438	0	0
Reclassification of net loss on derivative financial instruments	399	0	0
Other comprehensive income	(1,837)	0	0
COMPREHENSIVE INCOME (LOSS)	(77,247)	61,974	49,628
Comprehensive loss attributable to redeemable noncontrolling interests	7,103	0	0
Comprehensive loss attributable to noncontrolling interests	3	0	0
COMPREHENSIVE INCOME (LOSS) ATTRIBUTABLE TO COMMON SHAREHOLDERS	$ (70,141)	$ 61,974	$ 49,628

Consolidated and Combined Stat6

Consolidated and Combined Statements of Equity - USD ($) shares in Thousands, $ in Thousands		Total		Common Shares	Additional Paid-In Capital	Accumulated Deficit	Accumulated Other Comprehensive Income	Former Parent Equity		Noncontrolling Interests
Balance at beginning of period at Dec. 31, 2014		$ 1,988,915						$ 1,988,347		$ 568
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)		49,628						49,628
Deferred compensation shares and options, net		4,506						4,506
Contributions from former parent, net		16,442						16,495		(53)
Issuance of common shares in connection with the Combination	[1]	0
Other comprehensive income		0
Balance at end of period at Dec. 31, 2015		2,059,491						2,058,976		515
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)		61,974						61,974
Deferred compensation shares and options, net		4,502						4,502
Distributions to former parent, net		(3,983)						(3,763)		(220)
Issuance of common shares in connection with the Combination	[1]	0
Other comprehensive income		0
Balance at end of period at Dec. 31, 2016		2,121,984						2,121,689		295
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss attributable to common shareholders		(71,756)				$ (42,729)		(29,024)	[2]	(3)
Net income (loss)		(79,084)
Deferred compensation shares and options, net		1,526						1,526
Contributions from former parent, net		333,020						333,020
Issuance of common limited partnership units at the Separation		(96,632)						(96,632)
Issuance of common shares at the Separation (in shares)				94,736
Issuance of common shares at the Separation		0		$ 947	$ 2,329,632			(2,330,579)
Issuance of common shares in connection with the Combination (in shares)				23,219
Issuance of common shares in connection with the Combination		864,918	[1]	$ 233	864,685
Noncontrolling interests acquired in connection with the Combination		3,586								3,586
Dividends declared on common shares ($0.45 per common share)		(53,080)				(53,080)
Distributions to noncontrolling interests		(171)								(171)
Contributions from noncontrolling interests		499								499
Redeemable noncontrolling interest redemption value adjustment and other comprehensive income allocation		(130,917)			(130,692)		$ (225)
Other comprehensive income		$ 1,837					1,837
Balance at end of period (in shares) at Dec. 31, 2017		117,955		117,955
Balance at end of period at Dec. 31, 2017		$ 2,974,814		$ 1,180	$ 3,063,625	$ (95,809)	$ 1,612	$ 0		$ 4,206
[1]	See Note 3 for information regarding assets, liabilities and noncontrolling interests acquired in the Formation Transaction.
[2]	Net loss incurred from January 1, 2017 through July 17, 2017 is attributable to our former parent as it was the sole shareholder through July 17, 2017. See Note 1 for additional information.

Consolidated and Combined Stat7

Consolidated and Combined Statements of Equity (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Stockholders' Equity [Abstract]
Dividends declared (in dollars per share)	$ 0.45	$ 0	$ 0

Consolidated and Combined Stat8

Consolidated and Combined Statements of Cash Flows - USD ($)		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
OPERATING ACTIVITIES:
Net income (loss)		$ (79,084,000)	$ 61,974,000	$ 49,628,000
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Share-based compensation expense		33,693,000	4,502,000	4,506,000
Depreciation and amortization, including amortization of debt issuance costs		164,580,000	135,072,000	146,985,000
Deferred rent		(10,388,000)	(15,551,000)	(10,929,000)
Loss from unconsolidated real estate ventures, net		4,143,000	947,000	4,283,000
Amortization of above- and below-market lease intangibles, net		(862,000)	(1,353,000)	(2,797,000)
Amortization of lease incentives		4,023,000	3,592,000	2,570,000
Return on capital from unconsolidated real estate ventures		2,563,000	1,520,000	1,348,000
Gain on bargain purchase		(24,376,000)	0	0
Loss on extinguishment of debt		701,000	0	0
Realized loss on interest rate swaps and caps		27,000	0	0
Unrealized gain on interest rate swaps and caps		(1,348,000)	0	0
Bad debt expense		3,807,000	750,600	1,407,000
Other non-cash items		3,928,000	6,236,000	626,000
Deferred tax benefit		(10,408,000)	0	0
Changes in operating assets and liabilities:
Tenant and other receivables		(2,098,000)	(3,693,000)	(428,000)
Other assets, net		(23,481,000)	(16,614,000)	(13,667,000)
Accounts payable and accrued expenses		16,160,000	7,667,000	(4,004,000)
Other liabilities, net		(7,397,000)	(25,509,000)	(1,298,000)
Net cash provided by operating activities		74,183,000	159,541,000	178,230,000
INVESTING ACTIVITIES:
Development costs, construction in progress and real estate additions		(210,593,000)	(237,814,000)	(234,285,000)
Cash and restricted cash received in connection with the Combination, net		97,416,000	0	0
Acquisition of interests in unconsolidated real estate ventures, net of cash acquired		(8,834,000)	0	0
Distributions of capital from unconsolidated real estate ventures		6,929,000	0	0
Investments in and advances to unconsolidated real estate ventures		(16,321,000)	(23,027,000)	(7,865,000)
Repayment of notes receivable		50,934,000	0	0
Other investments		(2,207,000)	(1,966,000)	(1,467,000)
Proceeds from repayment of receivable from former parent		75,000,000	4,000,000	7,000,000
Net cash used in investing activities		(7,676,000)	(258,807,000)	(236,617,000)
FINANCING ACTIVITIES:
Contributions from (distributions to) former parent, net		160,203,000		16,495,000
Contributions from (distributions to) former parent, net			(3,763,000)
Repayment of borrowings from former parent		(115,630,000)	0	(13,600,000)
Proceeds from borrowings from former parent		4,000,000	79,500,000	96,512,000
Capital lease payments		(17,827,000)	0	0
Borrowings under mortgages payable		366,239,000	0	341,460,000
Borrowings under revolving credit facility		115,751,000	0	0
Borrowings under unsecured term loan		50,000,000	0	0
Repayments of mortgages payable		(272,905,000)	(24,364,000)	(315,824,000)
Debt issuance costs		(19,287,000)	(70,000)	(2,359,000)
Dividends paid to common shareholders		(26,540,000)
Distributions to redeemable noncontrolling interests		(4,556,000)	0	0
Contributions from noncontrolling interests		357,000	0	0
Distributions to noncontrolling interests		(18,000)	(220,000)	(13,000)
Net cash provided by financing activities		239,787,000	51,083,000	122,671,000
Net increase (decrease) in cash and cash equivalents and restricted cash		306,294,000	(48,183,000)	64,284,000
Cash and cash equivalents and restricted cash at beginning of the year		32,263,000	80,446,000	16,162,000
Cash and cash equivalents and restricted cash at end of the year		338,557,000	32,263,000	80,446,000
CASH AND CASH EQUIVALENTS AND RESTRICTED CASH AT END OF THE YEAR:
Cash and cash equivalents and restricted cash		32,263,000	80,446,000	16,162,000
SUPPLEMENTAL DISCLOSURE OF CASH FLOW AND NON-CASH INFORMATION:
Transfer of mortgage payable to former parent		115,630,000	115,022,000	0
Cash paid for interest (net of capitalized interest of $12,727, $4,076 and $6,437 in 2017, 2016 and 2015)		52,388,000	45,373,000	54,055,000
Accrued capital expenditures included in accounts payable and accrued expenses		12,445,000	8,851,000	29,400,000
Write-off of fully depreciated assets		55,998,000	100,076,000	23,155,000
Accrued lease incentives		0	0	30,514,000
Cash payments for income taxes		3,396,000	1,165,000	677,000
Non-cash contributions from redeemable noncontrolling interests	[1]	5,420,000	0	0
Non-cash transactions related to the Formation Transaction:
Issuance of common limited partnership units at the Separation	[2]	96,632,000	0	0
Issuance of common shares at the Separation	[2]	2,330,579,000	0	0
Issuance of common shares in connection with the Combination	[2]	864,918,000	0	0
Issuance of common limited partnership units in connection with the Combination	[2]	359,967,000	0	0
Adjustment to record redeemable noncontrolling interest at redemption value	[2]	130,692,000	0	0
Contribution from former parent in connection with the Separation	[2]	$ 172,817,000	$ 0	$ 0
[1]	See Note 11 for additional information.
[2]	See Note 3 for information regarding assets, liabilities and noncontrolling interests acquired in the Formation Transaction.

Consolidated and Combined Stat9

Consolidated and Combined Statements of Cash Flows (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Cash Flows [Abstract]
Capitalized interest	$ 12,727	$ 4,076	$ 6,437

Organization and Basis of Prese

Organization and Basis of Presentation	12 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Basis of Presentation	Organization and Basis of Presentation Organization JBG SMITH Properties ("JBG SMITH") was organized by Vornado Realty Trust ("Vornado" or "former parent") as a Maryland real estate investment trust ("REIT") on October 27, 2016 (capitalized on November 22, 2016). JBG SMITH was formed for the purpose of receiving, via the spin-off on July 17, 2017 (the "Separation"), substantially all of the assets and liabilities of Vornado’s Washington, DC segment, which operated as Vornado / Charles E. Smith, (the "Vornado Included Assets"). 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." Unless the context otherwise requires, all references to "we," "us," and "our," refer to the Vornado Included Assets (our predecessor and accounting acquirer) for periods prior to the Separation and to JBG SMITH for periods after the Separation. 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. Prior to the Separation from Vornado, JBG SMITH was a wholly owned subsidiary of Vornado and had no material assets or operations. On July 17, 2017, Vornado distributed 100% of the then outstanding common shares of JBG SMITH on a pro rata basis to the holders of its common shares. Prior to such distribution by Vornado, Vornado Realty L.P. ("VRLP"), Vornado's operating partnership, distributed common limited partnership units ("OP Units") in JBG SMITH LP on a pro rata basis to the holders of VRLP's common limited partnership units, consisting of Vornado and the other common limited partners of VRLP. Following such distribution by VRLP and prior to such distribution by Vornado, Vornado contributed to JBG SMITH all of the OP Units it received in exchange for common shares of JBG SMITH. Each Vornado common shareholder received one JBG SMITH common share for every two Vornado common shares held as of the close of business on July 7, 2017 (the "Record Date"). Vornado and each of the other limited partners of VRLP received one JBG SMITH LP OP Unit for every two common limited partnership units in VRLP held as of the close of business on the Record Date. Our operations are presented as if the transfer of the Vornado Included Assets had been consummated prior to all historical periods presented in the accompanying consolidated and combined financial statements at the carrying amounts of such assets and liabilities reflected in Vornado’s books and records. In connection with the Separation, JBG SMITH issued 94.7 million common shares and JBG SMITH LP issued 5.8 million OP Units to parties other than JBG SMITH. In connection with the Combination, JBG SMITH issued 23.2 million common shares and JBG SMITH LP issued 13.9 million OP Units to parties other than JBG SMITH. As of the completion of the Formation Transaction there were 118.0 million JBG SMITH common shares outstanding and 19.8 million JBG SMITH LP OP Units outstanding that were owned by parties other than JBG SMITH. As of December 31, 2017 , we, as its sole general partner, controlled JBG SMITH LP and owned 85.6% of its OP Units. We own and operate a portfolio of high-quality office 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, DC metropolitan area that have high barriers to entry and key urban amenities, including being within walking distance of a Metro station. As of December 31, 2017 , our Operating Portfolio consists of 69 operating assets comprising 51 office assets totaling over 13.7 million square feet ( 11.8 million square feet at our share), 14 multifamily assets totaling 6,016 units ( 4,232 units at our share) and four other assets totaling approximately 765,000 square feet ( 348,000 square feet at our share). Additionally, we have (i) ten assets under construction comprising four office assets totaling approximately 1.3 million square feet ( 1.2 million square feet at our share), five multifamily assets totaling 1,767 units ( 1,568 units at our share) and one other asset totaling approximately 41,100 square feet ( 4,100 square feet at our share); and (ii) 43 future development assets totaling approximately 21.4 million square feet ( 17.9 million square feet at our share) of estimated potential development density. Our revenues are derived primarily from leases with office and multifamily tenants, including fixed rents and reimbursements from tenants for certain expenses such as real estate taxes, property operating expenses, and repairs and maintenance. In addition, we have a third-party real estate services business that provides fee-based real estate services to the legacy funds formerly organized by The JBG Companies ("JBG Legacy Funds") and other third parties. As of December 31, 2017 , five of our assets in the aggregate generated approximately 25% of our share of annualized rent. Only the U.S. federal government accounted for 10% or more of our rental revenue, which consists of property rentals and tenant reimbursements, during each of the three years in the period ended December 31, 2017 as follows: Year Ended December 31, (Dollars in thousands) 2017 2016 2015 Rental revenue from the U.S. federal government $ 92,192 $ 103,864 $ 102,951 Percentage of office segment rental revenue 24.5 % 29.6 % 29.7 % Percentage of total rental revenue 19.4 % 23.6 % 23.9 % Basis of Presentation The accompanying consolidated and combined financial statements and notes are prepared in accordance with accounting principles generally accepted in the United States of America ("GAAP"). All intercompany transactions and balances have been eliminated. The accompanying consolidated and combined 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 6 for additional information on our consolidated VIEs. The portions of the equity and net income (loss) of consolidated subsidiaries that are not attributable to JBG SMITH are presented separately as amounts attributable to noncontrolling interests in the consolidated and combined financial statements. References to the financial statements refer to our consolidated and combined financial statements as of December 31, 2017 and 2016 , and for each of the three years in the period ended December 31, 2017 . References to the balance sheets refer to our consolidated and combined balance sheets as of December 31, 2017 and 2016 . References to the statement of operations refer to our consolidated and combined statements of operations for each of the three years in the period ended December 31, 2017 . References to the statement of cash flows refer to our consolidated and combined statements of cash flows for each of the three years in the period ended December 31, 2017 . Combination JBG SMITH and the Vornado Included Assets were under common control of Vornado for all periods prior to the Separation. The transfer of the Vornado Included Assets from Vornado to JBG SMITH was completed prior to the Separation, at net book values (historical carrying amounts) carved out from Vornado’s books and records. For purposes of the formation of JBG SMITH, the Vornado Included Assets were designated as the predecessor and the accounting acquirer of the JBG Assets. Consequently, the financial statements of JBG SMITH, as set forth herein, represent a continuation of the financial information of the Vornado Included Assets as the predecessor and accounting acquirer such that the historical financial information included herein as of any date or for any periods on or prior to the completion of the Combination represents the pre-Combination financial information of the Vornado Included Assets. The financial statements reflect the common shares as of the date of the Separation as outstanding for all periods prior to July 17, 2017. The acquisition of the JBG Assets completed subsequently by JBG SMITH was accounted for as a business combination using the acquisition method whereby identifiable assets acquired and liabilities assumed are recorded at the acquisition-date fair values and income and cash flows from the operations were consolidated into the financial statements of JBG SMITH commencing July 18, 2017. Consequently, the financial statements for the periods before and after the Formation Transaction are not directly comparable. The accompanying statements of operations for the year ended December 31, 2017 include our consolidated accounts and the combined accounts of the Vornado Included Assets. Accordingly, the results of operations for the year ended December 31, 2017 reflect the aggregate operations and changes in cash flows and equity on a combined basis for the period prior to July 17, 2017 and on a consolidated basis for the period subsequent to July 17, 2017. The accompanying financial statements for the years ended December 31, 2016 and 2015 include the Vornado Included Assets. Therefore, our results of operations, cash flows and financial condition set forth in this report are not necessarily indicative of our future results of operations, cash flows or financial condition as an independent, publicly traded company. The historical financial results for the Vornado Included Assets reflect charges for certain corporate costs allocated by the former parent which we believe are reasonable. These charges were based on either actual costs incurred or a proportion of costs estimated to be applicable to the Vornado Included Assets based on an analysis of key metrics, including total revenues. Such costs do not necessarily reflect what the actual costs would have been if JBG SMITH had been operating as a separate standalone public company. See Note 18 for additional information. Reclassifications Certain prior period data have been reclassified to conform to the current period presentation as follows: • Reclassification of $4.0 million of investments to "Other assets" on our balance sheet as of December 31, 2016 as a result of the revision in the line item "Investments in and advances to unconsolidated real estate ventures" on our balance sheet to include only real estate investments. • Reclassification of $19.1 million and $18.2 million of expenses for the years ended December 31, 2016 and 2015 to "General and administrative: third-party real estate services" from "Property operating expenses" as it relates to expenses incurred to provide third-party real estate services. Additionally, we reclassified $16.4 million and $15.9 million of income for the years ended December 31, 2016 and 2015 to "Third-party real estate services, including reimbursements" from "Other income" as it relates to revenue earned from providing third-party real estate services.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Use of Estimates The preparation of the financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at 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 to establish the fair values recorded in connection with the Combination and used in assessing impairment, (ii) the determination of useful lives for tangible and intangible assets and (iii) the allowance for doubtful accounts. Actual results could differ from those estimates. Business Combinations We account for business combinations, including the acquisition of real estate, using the acquisition method pursuant to which we recognize and measure the identifiable assets acquired, liabilities assumed, and any noncontrolling interests in the acquiree at their acquisition date fair values. Accordingly, we estimate the fair values of acquired tangible assets (consisting of real estate, cash and cash equivalents, tenant and other receivables, investments in unconsolidated real estate ventures and other assets, as applicable), identified intangible assets and liabilities (consisting of the value of in-place leases, above- and below-market leases, options to enter into ground leases and management contracts, as applicable), assumed debt and other liabilities, and noncontrolling interests, as applicable, based on our evaluation of information and estimates available at that date. Based on these estimates, we allocate the purchase price to the identified assets acquired and liabilities assumed. Any excess of the purchase price over the estimated fair value of the net assets acquired is recorded as goodwill. Any excess of the fair value of assets acquired over the purchase price is recorded as a gain on bargain purchase. If, up to one year from the acquisition date, information regarding the fair value of the net assets acquired and liabilities assumed is received and estimates are refined, appropriate adjustments are made on a prospective basis to the purchase price allocation, which may include adjustments to identified assets, assumed liabilities, and goodwill or the gain on bargain purchase, as applicable. The results of operations of acquisitions are prospectively included in our financial statements beginning with the date of the acquisition. Transaction costs related to business combinations are expensed as incurred and included in "Transaction and other costs" in our statements of operations. The fair values of buildings are determined using the "as-if vacant" approach whereby we use discounted income or cash flow models with inputs and assumptions that we believe are consistent with current market conditions for similar assets. The most significant assumptions in determining the allocation of the purchase price to buildings are the exit capitalization rate, discount rate, estimated market rents and hypothetical expected lease-up periods. We assess fair value of land based on market comparisons and development projects using an income approach of cost plus a margin. The fair values of identified intangible assets are determined based on the following: • The value allocable to the above- or below-market component of an acquired in-place lease is determined based upon the present value (using a discount rate which reflects the risks associated with the acquired leases) of the difference between (i) the contractual amounts to be received pursuant to the lease over its remaining term and (ii) management’s estimate of the amounts that would be received using market rates over the remaining term of the lease. Amounts allocated to above- market leases are recorded as "Identified intangible assets" in "Other assets, net" in the balance sheets, and amounts allocated to below-market leases are recorded as "Lease intangible liabilities" in "Other liabilities, net" in the balance sheets. These intangibles are amortized to "Property rentals" in our statements of operations over the remaining terms of the respective leases. • Factors considered in determining the value allocable to in-place leases during hypothetical lease-up periods related to space that is leased at the time of acquisition include (i) lost rent and operating cost recoveries during the hypothetical lease-up period and (ii) theoretical leasing commissions required to execute similar leases. These intangible assets are recorded as "Identified intangible assets" in "Other assets, net" in the balance sheets and are amortized to "Depreciation and amortization expenses" in our statements of operations over the remaining term of the existing lease. • The fair value of the in-place property management, leasing, asset management, and development and construction management contracts is based on revenue and expense projections over the estimated life of each contract discounted using a market discount rate. These management contract intangibles are amortized to "Depreciation and amortization expenses" in our statements of operations over the weighted average life of the management contracts. The fair value of investments in unconsolidated real estate ventures and related noncontrolling interests is based on the estimated fair values of the identified assets acquired and liabilities assumed of each venture, including future expected cash flows from promote interests. The fair value of the mortgages payable assumed was determined using current market interest rates for comparable debt financings. The fair values of the interest rate swaps and caps are based on the estimated amounts we would receive or pay to terminate the contract at the acquisition date and are determined using interest rate pricing models and observable inputs. The carrying value of cash, restricted cash, working capital balances, leasehold improvements and equipment, and other assets acquired and liabilities assumed approximates fair value. Real Estate Real estate is carried at cost, net of accumulated depreciation and amortization. Maintenance and repairs are expensed as incurred and are included in "Property operating expenses" in our statements of operations. As real estate is undergoing redevelopment activities, all property operating expenses directly associated with and attributable to the redevelopment, including interest expense, are capitalized to the extent that we believe such costs are recoverable through the value of the property. The capitalization period ends when redevelopment activities are substantially complete. General and administrative costs are expensed as incurred. Depreciation requires an estimate of the useful life of each property and improvement as well as an allocation of the costs associated with a property to its various components. Depreciation is recognized on a straight‑line basis over estimated useful lives, which range from three to 40 years . Tenant improvements are amortized on a straight‑line basis over the lives of the related leases, which approximate the useful lives of the tenant improvements. Construction in progress, including land, is carried at cost, and no depreciation is recorded. Real estate undergoing significant renovations and improvements is considered to be under development. All direct and indirect costs related to development activities are capitalized into "Construction in progress, including land" on our balance sheets, except for certain demolition costs, which are expensed as incurred. Direct development costs incurred include: pre-development expenditures directly related to a specific project, development and construction costs, interest, insurance and real estate taxes. Indirect development costs include: employee salaries and benefits, travel and other related costs that are directly associated with the development. Our method of calculating capitalized interest expense is based upon applying our weighted average borrowing rate to the actual accumulated expenditures if the property does not have property specific debt. If the property is encumbered by specific debt, we will capitalize both the interest incurred applicable to that debt and additional interest expense using our weighted average borrowing rate for any accumulated expenditures in excess of the principal balance of the debt encumbering the property. The capitalization of such expenses ceases when the real estate is ready for its intended use, but no later than one-year from substantial completion of major construction activity. If we determine that a project is no longer viable, all pre-development project costs are immediately expensed. Our assets and related intangible assets are individually reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of the assets may not be recoverable. An impairment exists when the carrying amount of an asset exceeds the sum of the undiscounted cash flows expected to result from the use and eventual disposition of the asset. Estimates of future cash flows are based on our current plans, intended holding periods and available market information at the time the analyses are prepared. An impairment loss is recognized if the carrying amount of the asset is not recoverable and is measured based on the excess of the property’s carrying amount over its estimated fair value. If our estimates of future cash flows, anticipated holding periods, or fair values change, based on market conditions or otherwise, our evaluation of impairment charges may be different and such differences could be material to our financial statements. Estimates of future cash flows are subjective and are based, in part, on assumptions regarding future occupancy, rental rates and capital requirements that could differ materially from actual results. Real estate is classified as held for sale when all the necessary criteria are met. The criteria include (i) management, having the authority to approve action, commits to a plan to sell the property in its present condition, (ii) the sale of the property is at a price reasonable in relation to its current fair value and (iii) the sale is probable and expected to be completed within one year. Real estate held for sale is carried at the lower of carrying amounts or estimated fair value less disposal costs. Depreciation and amortization is not recognized on real estate classified as held for sale. Cash and Cash Equivalents Cash and cash equivalents consist of highly liquid investments with a purchase date life to maturity of three months or less and are carried at cost, which approximates fair value, due to their short‑term maturities. Restricted Cash Restricted cash consists primarily of security deposits held on behalf of our tenants and cash escrowed under loan agreements for debt service, real estate taxes, property insurance and capital improvements. Allowance for Doubtful Accounts We periodically evaluate the collectability of amounts due from tenants, including the receivable arising from deferred rent receivable, and maintain an allowance for doubtful accounts for the estimated losses resulting from the inability of tenants to make required payments under lease agreements. We exercise judgment in establishing these allowances and consider payment history and current credit status in developing these estimates. Investments in and Advances to Real Estate Ventures We analyze our real estate ventures to determine whether the entities should be consolidated. If it is determined that these investments do not require consolidation because the entities are not VIEs in accordance with the Consolidation Topic of the Financial Accounting Standards Board ("FASB"), Accounting Standards Codification ("ASC"), we are not considered the primary beneficiary of the entities determined to be VIEs, we do not have voting control, and/or the limited partners (or non-managing members) have substantive participatory rights, then the selection of the accounting method used to account for our investments in unconsolidated real estate ventures is generally determined by our voting interests and the degree of influence we have over the entity. Management uses its judgment when determining if we are the primary beneficiary of, or have a controlling financial interest in, an entity in which we have a variable interest. Factors considered in determining whether we have the power to direct the activities that most significantly impact the entity’s economic performance include risk and reward sharing, experience and financial condition of the other partners, voting rights, involvement in day-to-day capital and operating decisions and the extent of our involvement in the entity. We use the equity method of accounting for investments in unconsolidated real estate ventures when we own 20% or more of the voting interests and have significant influence but do not have a controlling financial interest, or if we own less than 20% of the voting interests but have determined that we have significant influence. Under the equity method, we record our investments in and advances to these entities in our balance sheets, and our proportionate share of earnings or losses earned by the real estate venture is recognized in "Income (loss) from unconsolidated real estate ventures, net" in the accompanying statements of operations. We earn revenues from the management services we provide to unconsolidated entities. These fees are 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. We account for this revenue gross of our ownership interest in each respective real estate venture and recognize such revenue in "Third-party real estate services, including reimbursements" in our statements of operations. Our proportionate share of related expenses is recognized in "Income (loss) from unconsolidated real estate ventures, net" in our statements of operations. We may also earn incremental promote distributions if certain financial return benchmarks are achieved upon ultimate disposition of the underlying properties. Management fees are recognized when earned, and promote fees are recognized when certain earnings events have occurred, and the amount is determinable and collectible. Any promote fees are reflected in "Income (loss) from unconsolidated real estate ventures, net" in our statements of operations. With regard to distributions from unconsolidated real estate ventures, we use the information that is available to us to determine the nature of the underlying activity that generated the distributions. Using the nature of distribution approach, cash flows generated from the operations of an unconsolidated real estate venture are classified as a return on investment (cash inflow from operating activities) and cash flows that from property sales, debt refinancing or sales of our investments are classified as a return of investment (cash inflow from investing activities). On a periodic basis, we evaluate our investments in unconsolidated entities for impairment. We assess whether there are any indicators, including underlying property operating performance and general market conditions, that the value of our investments in unconsolidated real estate ventures may be impaired. An investment in a real estate venture is considered impaired if we determine that its fair value is less than the net carrying value of the investment in that real estate venture on an other-than-temporary basis. Cash flow projections for the investments consider property level factors such as expected future operating income, trends and prospects, as well as the effects of demand, competition and other factors. We consider various qualitative factors to determine if a decrease in the value of our investment is other-than-temporary. These factors include age of the venture, our intent and ability to retain our investment in the entity, financial condition and long-term prospects of the entity and relationships with our partners and banks. If we believe that the decline in the fair value of the investment is temporary, no impairment charge is recorded. If our analysis indicates that there is an other-than temporary impairment related to the investment in a particular real estate venture, the carrying value of the venture will be adjusted to an amount that reflects the estimated fair value of the investment. Intangibles Intangible assets consist of in-place leases, below-market ground rent obligations, above-market real estate leases and options to enter into ground lease that were recorded in connection with the acquisition of properties. Intangible assets also include management and leasing contracts acquired in the Combination. Intangible liabilities consist of above-market ground rent obligations and below-market real estate leases that are also recorded in connection with the acquisition of properties. Both intangible assets and liabilities are amortized and accreted using the straight-line method over their applicable remaining useful life. When a lease or contract is terminated early, any remaining unamortized or unaccreted balances are charged to earnings. The useful lives of intangible assets are evaluated each reporting period with any changes in estimated useful lives being accounted for over the revised remaining useful life. Deferred Costs Deferred financing costs consist of loan issuance costs directly related to financing transactions that are deferred and amortized over the term of the related loan as a component of interest expense. Unamortized deferred financing costs related to our mortgages payable and unsecured term loan are presented as a direct deduction from the carrying amounts of the related debt instruments, while such costs related to our revolving credit facility are included in other assets. Direct salaries, third-party fees and other costs incurred by us to originate a lease are capitalized in "Other assets, net" in the balance sheets and are amortized against the respective leases using the straight-line method over the term of the related leases. Noncontrolling Interests We identify our noncontrolling interests separately within the equity section on the balance sheets. Amounts of consolidated net income (loss) attributable to redeemable noncontrolling interests and to the noncontrolling interests in consolidated subsidiaries are presented separately in the statements of operations. Redeemable Noncontrolling Interests - Redeemable noncontrolling interests consists of OP Units issued in conjunction with the Formation Transaction and our venture partner's interest in 965 Florida Avenue. The OP Units are redeemable for our common shares or cash beginning August 1, 2018, subject to certain limitations. Redeemable noncontrolling interests are generally redeemable at the option of the holder and are presented in the mezzanine section between total liabilities and shareholders' equity on the balance sheets. The carrying amount of redeemable noncontrolling interests is adjusted to its redemption value at the end of each reporting period, but no less than its initial carrying value, with such adjustments recognized in "Additional paid-in capital". See Note 11 for additional information. Noncontrolling Interests - Noncontrolling interests represents the portion of equity that we do not own in entities we consolidate, including interests in consolidated real estate ventures. Derivative Financial Instruments and Hedge Accounting Derivative financial instruments are used at times to manage exposure to variable interest rate risk. Derivative financial instruments are recognized as either assets or liabilities and are measured at fair value. The accounting for changes in the fair value of a derivative depends on the intended use of the derivative and the resulting designatio n. Derivative Financial Instruments Designated as Cash Flow Hedges - Certain derivative financial instruments, consisting of interest rate swap and cap agreements, are designated as cash flow hedges, and are carried at their estimated fair value on a recurring basis. We assess the effectiveness of our cash flow hedges both at inception and on an ongoing basis. If the hedges are deemed to be effective, the fair value is recorded in accumulated other comprehensive income and is subsequently reclassified into "Interest expense" in the period that the hedged forecasted transactions affect earnings. Our cash flow hedges become less than perfectly effective if the critical terms of the hedging instrument and the forecasted transactions do not perfectly match such as notional amounts, settlement dates, reset dates, calculation period and interest rates. In addition, we evaluate the default risk of the counterparty by monitoring the credit worthiness of the counterparty. Derivative instruments and hedging activities require management to make judgments on the nature of its derivatives and their effectiveness as hedges. These judgments determine if the changes in fair value of the derivative instruments are reported in the statements of operations or as a component of comprehensive income and as a component of shareholders’ equity on the balance sheets. Derivative Financial Instruments Not Designated as Hedges - Certain derivative financial instruments, consisting of interest rate swap and cap agreements, are considered economic hedges, but not designated as accounting hedges, and are carried at their estimated fair value on a recurring basis. Realized and unrealized gains are recorded in "Interest expense" in the statements of operations in the period in which the change occurs. Fair Value of Assets and Liabilities ASC 820, Fair Value Measurement and Disclosures, defines fair value and establishes a framework for measuring fair value. The objective of fair value is to determine the price that would be received upon the sale of an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (the exit price). ASC 820 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 value hierarchy gives the highest priority to Level 1 inputs and the lowest priority to Level 3 inputs. In determining fair value, we utilize valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs to the extent possible as well as consider counterparty credit risk in our assessment of fair value. Revenue Recognition Property rentals income includes base rents that 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 leases. We commence rental revenue recognition when the tenant takes possession of the leased space or controls the physical use of the leased space and 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 income 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 also includes the amortization/accretion of acquired above-and below-market leases. Tenant reimbursements provide for the recovery of all or a portion of the operating expenses and real estate taxes of the respective assets. Tenant reimbursements are accrued in the same periods as the related expenses are incurred. 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. Development and construction fees earned from providing services to our unconsolidated real estate ventures are recorded on a percentage of completion basis. Third-Party Real Estate Services Expenses Third-party real estate services expenses include the costs associated with the management services provided to our unconsolidated real estate ventures and other third parties. We allocate personnel and other overhead costs using the estimates of the time spent performing services for our third-party real estate services and other allocation methodologies. Income Taxes We intend to elect 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. Prior to the Separation, Vornado operated as a REIT and distributed 100% of taxable income to its shareholders, accordingly, no provision for federal income taxes has been made in the accompanying financial statements for the periods prior to the Separation. We intend to adhere to these requirements and maintain our REIT status in future periods. As a REIT, we are allowed to reduce taxable income by all or a portion of our distributions to shareholders. Future distributions will be declared and paid at the discretion of the Board of Trustees and will depend upon cash generated by operating activities, our financial condition, capital requirements, annual dividend requirements under the REIT provisions of the Code, as amended, and such other factors as our Board of Trustees deems relevant. We also participate in the activities conducted by subsidiary entities which have elected to be treated as taxable REIT subsidiaries ("TRS") under the Code. As such, we are subject to federal, state, and local taxes on the income from these activities. Income taxes attributable to our TRSs are accounted for under the asset and liability method. Under the asset and liability method, deferred income taxes arise from temporary differences between the tax basis of assets and liabilities and their reported amounts in the financial statements, which will result in taxable or deductible amounts in the future. ASC 740-10, Income Taxes, provides guidance for how uncertain tax positions should be recognized, measured, presented and disclosed in the financial statements. ASC 740-10 requires the evaluation of tax positions taken in the course of preparing our tax returns to determine whether the tax positions are "more-likely-than-not" of being sustained by the applicable tax authority. Tax benefits of positions not deemed to meet the more-likely-than-not threshold are recorded as a tax expense in the current year. Earnings (Loss) Per Common Share Basic earnings (loss) per common share is computed by dividing net income (loss) attributable to common shareholders by the weighted average common shares outstanding during the period. Unvested and vested share-based payment awards that entitle holders to receive non-forfeitable dividends, which include OP Units and long-term incentive partnership units ("LTIP Units"), are considered participating securities. Consequently, we are required to apply the two-class method of computing basic and diluted earnings that would otherwise have been available to common shareholders. Under the two-class method, earnings for the period are allocated between common shareholders and participating securities based on their respective rights to receive dividends. During periods of net loss, losses are allocated only to the extent the participating securities are required to absorb their share of such losses. Diluted earnings per common share reflects the potential dilution of the assumed exchange of various units into common shares unvested share-based payment awards to the extent they are dilutive. Share-Based Compensation We granted OP Units, formation awards ("Formation Awards"), LTIP Units, LTIP Units with time-based vesting requirements (“Time-Based LTIP Units”) and Performance-Based LTIP Units to our trustees, management and employees in connection with the Separation and Combination. Fair value is determined, depending on the type of award, using the Monte Carlo method or post-vesting restriction periods, which is intended to estimate the fair value of the awards at the grant date using dividend yields and expected volatilities that are primarily based on available implied data and peer group companies' historical data. The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the time of grant. The shortcut method is used for determining the expected life used in the valuation method. Compensation expense is based on the fair value of our common shares at the date of the grant and is recognized ratably over the vesting period using a graded vesting attribution model. We account for forfeitures as they occur. Distributions paid on unvested OP Units, LTIP Units, Time-Based LTIP Units and Performance-Based LTIP Units are charged to "Net income attributable to noncontrolling interests" in the statements of operations. Recent Accounting Pronouncements The following table provides a brief description of recent accounting pronouncements (ASU) by the FASB that could have a material effect on our financial statements: Standard Description Date of Adoption Effect on the Financial Statements or Other Significant Matters Standards adopted ASU 2016-15, These standards amend the existing guidance and address specific cash flow issues with the objective of reducing existing diversity in practice. ASU 2016-15 addresses eight specific cash flow issues and ASU 2016-18 specifically addresses presentation of restricted cash and restricted cash equivalents in the statements of cash flows. These standards are effective for interim and annual reporting periods in fiscal years beginning after December 15, 2017, with early adoption permitted. These standards require a retrospective transition method to each period presented. If it is impracticable to apply the amendments retrospectively for some of the issues, entities may apply the amendments prospectively as of the earliest date practicable. December 2017 Other than the revised statement of cash flows presentation of restricted cash, the adoption and implementation of these standards did not have a material impact on our financial statements. The standards were retrospectively applied to prior years. ASU 2017‑05, Other Income—Gains and Losses from the Derecognition of Nonfinancial Assets (Subtopic 610-20): Clarifying the Scope of Asset Derecognition Guidance and Accounting for Partial Sales of Nonfinancial Assets This standard clarifies the scope of recently established guidance on nonfinancial asset derecognition as well as the accounting for partial sales of nonfinancial assets. This update conforms the derecognition guidance on nonfinancial assets with the model for transactions in ASC 606. This standard is effective for interim and annual reporting periods in fiscal years beginning after December 15, 2017, with early adoption permitted. This standard may be adopted either retrospectively or on a modified retrospective basis. December 2017 The adoption and implementation of this standard did not have an impact on our financial statements. In future periods, the adoption of this standard could have a material impact to our results of operations if we sell a significant partial interest in a real estate asset. ASU 2017‑09, Compensation—Stock Compensation (Topic 718): Scope of Modification Accounting This standard clarifies which changes to the terms

The Combination

The Combination	12 Months Ended
	Dec. 31, 2017
Business Combinations [Abstract]
The Combination	The Combination In the Combination on July 18, 2017, we acquired the JBG Assets in exchange for approximately 37.2 million common shares and OP Units. The Combination has been accounted for at fair value under the acquisition method of accounting. The following allocation of the purchase price is based on the preliminary fair value of the assets acquired and liabilities assumed (in thousands): Fair value of purchase consideration: Common shares and OP Units $ 1,224,885 Cash 20,573 Total consideration paid $ 1,245,458 Fair value of assets acquired and liabilities assumed: Land and improvements $ 338,072 Building and improvements 609,156 Construction in progress, including land 699,800 Leasehold improvements and equipment 7,890 Real estate 1,654,918 Cash 104,529 Restricted cash 13,460 Investments in and advances to unconsolidated real estate ventures 241,611 Identified intangible assets 138,371 Notes receivable (1) 50,934 Identified intangible liabilities (8,687 ) Mortgages payable assumed (2) (768,523 ) Capital lease obligations assumed (3) (33,543 ) Lease assumption liabilities (4) (43,388 ) Deferred tax liability (5) (18,610 ) Other liabilities acquired, net (57,650 ) Noncontrolling interests in consolidated subsidiaries (3,588 ) Net assets acquired 1,269,834 Gain on bargain purchase (6) 24,376 Total consideration paid $ 1,245,458 ____________________ (1) During the year ended December 31, 2017 , we received proceeds of $50.9 million from the repayment of the notes receivable acquired in the Combination. (2) Subject to various interest rate swap and cap agreements assumed in the Combination that are considered economic hedges, but not designated as accounting hedges. (3) In the Combination, two ground leases were assumed that were determined to be capital leases. On July 25, 2017, we purchased a land parcel located in Reston, Virginia associated with one of the ground leases for $19.5 million . (4) Includes a $14.0 million payment to a tenant, which will be paid in 2018, and a $29.4 million lease liability we assumed in relocating a tenant to one of our office buildings. The $29.4 million assumed lease liability is based on the contractual payments we assumed under the tenant’s previous lease, which are partially offset by estimated sub-tenant income we anticipate receiving as we actively pursue a sub-tenant. (5) Related to the management and leasing contracts acquired in the Combination. (6) The Combination resulted in a gain on bargain purchase because the estimated fair value of the identifiable net assets acquired exceeded the purchase consideration by $24.4 million . The purchase consideration was based on the fair value of the common shares and OP Units issued in the Combination. We continue to reassess the recognition and measurement of identifiable assets and liabilities acquired and have preliminarily concluded that all acquired assets and liabilities were recognized and that the valuation procedures and resulting estimates of fair values were appropriate. During the fourth quarter of 2017 , as a result of our continuing reassessment of our fair value estimates, we made adjustments to the fair value of certain assets acquired and liabilities assumed primarily related to an increase of $47.5 million to real estate, a decrease of $8.2 million to identified intangible assets related to management and leasing contracts, an increase of $3.2 million to investments in and advances to unconsolidated real estate ventures, an increase of $43.4 million to lease assumption liability, an increase of $5.6 million to other liabilities acquired and a decrease of $2.9 million to deferred tax liability, resulting in a reduction to the gain on bargain purchase of $3.4 million . The fair value of the common shares and OP Units purchase consideration was determined as follows (i n thousands, except exchange ratio and price per share/unit): Outstanding common shares and common limited partnership units prior to the Combination 100,571 Exchange ratio (1) 2.71 Common shares and OP Units issued in consideration 37,164 Price per share/unit (2) $ 37.10 Fair value of common shares and OP Units issued in consideration $ 1,378,780 Fair value adjustment to OP Units due to transfer restrictions (43,303 ) Portion of consideration attributable to performance of future services (3) (110,591 ) Fair value of common shares and OP Units purchase consideration $ 1,224,886 ____________________ (1) Represents the implied exchange ratio of one common share and OP Unit of JBG SMITH for 2.71 common shares and common limited partnership units prior to the Combination. (2) Represents the volume weighted average share price on July 18, 2017. (3) OP Unit consideration paid to certain of the owners of the JBG Assets which have an estimated fair value of $ 110.6 million is subject to post-combination employment with vesting over periods of either 12 or 60 months and amortization is recognized as compensation expense over the period of employment in "General and administrative expense: Share-based compensation related to Formation Transaction" in the statements of operations. The JBG Assets acquired on July 18, 2017 comprise: (i) 30 operating assets comprising 19 office assets totaling approximately 3.6 million square feet ( 2.3 million square feet at our share), nine multifamily assets with 2,883 units ( 1,099 units at our share) and two other assets totaling approximately 490,000 square feet ( 73,000 square feet at our share); (ii) 11 office and multifamily assets under construction totaling over 2.5 million square feet ( 2.2 million square feet at our share); (iii) two near-term development office and multifamily assets totaling approximately 401,000 square feet ( 242,000 square feet at our share); (iv) 26 future development assets totaling approximately 11.7 million square feet ( 8.5 million square feet at our share) of estimated potential development density; and (v) JBG/Operating Partners, L.P., a real estate services company providing investment, development, asset management, property management, leasing, construction management and other services. JBG/Operating Partners, L.P. was owned by 20 unrelated individuals of which 19 became our employees, and three serve on our Board of Trustees. The preliminary estimated fair values of tangible and identified intangible assets and liabilities, which have definite lives, are as follows: Total Fair Value Weighted Average Amortization Period Useful Life (1) (In thousands) (In years) Tangible assets: Building and improvements $ 543,584 3 - 40 years Tenant improvements 65,572 Shorter of useful life or remaining life of the respective lease Total building and improvements $ 609,156 Leasehold improvements $ 4,422 Shorter of useful life or remaining life of the respective lease Equipment 3,468 5 years Total leasehold improvements and equipment $ 7,890 Identified intangible assets: In-place leases $ 60,317 6.4 Remaining life of the respective lease Above-market real estate leases 11,732 6.3 Remaining life of the respective lease Below-market ground leases 332 88.5 Remaining life of the respective lease Option to enter into ground lease 17,090 N/A Remaining life of contract Management and leasing contracts (2) 48,900 7.5 Estimated remaining life of contracts, ranging between 3 - 9 years Total identified intangible assets $ 138,371 Identified intangible liabilities: Below-market real estate leases $ 8,687 10.3 Remaining life of the respective lease ____________________ (1) In determining these useful lives, we considered the length of time the asset had been in existence, the maintenance history, as well as anticipated future maintenance, and any contractual stipulations that might limit the useful life. (2) Includes in-place property management, leasing, asset management and development management contracts. Transaction costs and other costs (such as advisory, legal, accounting, valuation and other professional fees) incurred to affect the Formation Transaction are included in "Transaction and other costs" in our statements of operations. Transaction and other costs of $127.7 million and $6.5 million were incurred during the years ended December 31, 2017 and 2016 . For the year ended December 31, 2017 , transaction and other costs include severance and transaction bonus expense of $40.8 million , investment banking fees of $33.6 million , legal fees of $13.9 million and accounting fees of $10.8 million . The total revenue and net loss of the JBG Assets for the year ended December 31, 2017 included in our statements of operations from the acquisition date was $71.3 million and $23.1 million . The accompanying unaudited pro forma information for the two years in the period ended December 31, 2017 is presented as if the Formation Transaction had occurred on January 1, 2016. This pro forma information is based upon the historical financial statements. This unaudited pro forma information does not purport to represent what the actual results of our operations would have been, nor does it purport to predict the results of operations of future periods. The unaudited pro forma information for the year ended December 31, 2017 was adjusted to exclude $24.4 million of gain on bargain purchase. The unaudited pro forma information was adjusted to exclude transaction and other costs of $127.7 million and $6.5 million and their respective income tax benefits for the years ended December 31, 2017 and 2016 . Year Ended December 31, 2017 2016 (In thousands, except per share data) Unaudited pro forma information: Total revenue $ 637,672 $ 655,668 Net loss attributable to common shareholders $ (19,343 ) $ (26,961 ) Loss per common share: Basic $ (0.16 ) $ (0.23 ) Diluted $ (0.16 ) $ (0.23 )

Tenants and Other Receivables,

Tenants and Other Receivables, Net	12 Months Ended
	Dec. 31, 2017
Receivables [Abstract]
Tenant and Other Receivables, Net	Tenant and Other Receivables, Net The following is a summary of tenant and other receivables, net as of December 31, 2017 and 2016 : December 31, 2017 2016 (In thousands) Tenants $ 30,672 $ 26,278 Third-party real estate services 8,954 2,488 Other 12,992 8,826 Allowance for doubtful accounts (5,884 ) (4,212 ) Total tenant and other receivables, net $ 46,734 $ 33,380 We incurred bad debt expense of approximately $3.8 million , $750,600 and $1.4 million during each of the three years in the period ended December 31, 2017 , which is included in "Property operating expenses" in the statements of operations.

Investments in and Advances to

Investments in and Advances to Unconsolidated Real Estate Ventures	12 Months Ended
	Dec. 31, 2017
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 as of December 31, 2017 and 2016 : Ownership Interest (1) December 31, Real Estate Venture Partners (1) December 31, 2017 2016 (In thousands) Landmark 1.8% - 49.0% $ 95,368 $ — CBREI Venture 5.0% - 64.0% 79,062 — Canadian Pension Plan Investment Board ("CPPIB") 55.0% 36,317 36,312 Brandywine 30.0% 13,741 — Berkshire Group 50.0% 27,761 — JP Morgan 5.0% 9,296 9,335 Other 246 129 Total investments in unconsolidated real estate ventures 261,791 45,776 Advances to unconsolidated real estate ventures 20 — Total investments in and advances to unconsolidated real estate ventures $ 261,811 $ 45,776 _______________ (1) We aggregate our investments in and advances to unconsolidated real estate ventures by real estate venture partner. We have multiple investments with certain venture partners with varying ownership interests. In November 2017, we acquired the remaining 41.0% interest in the Capitol Point - North unconsolidated real estate venture, which was part of our real estate venture with Landmark for $13.1 million . Subsequent to the acquisition, we consolidated Capitol Point - North. In November 2017, our real estate venture with CBREI closed a $110.0 million refinancing on Atlantic Plumbing, a multifamily and retail asset in the U Street/Shaw submarket of Washington, DC. The loan has a five -year term and bears interest at a variable rate of one-month LIBOR plus 1.50% . A prior swap agreement was novated to synthetically fix the interest rate through September 2020, and we are responsible for the related premiums. At closing, $100.0 million was funded, which was used in part to repay the existing $88.4 million loan. The real estate venture has the ability to draw an additional $10.0 million based on the asset’s performance. The following is a summary of the debt of our unconsolidated real estate ventures as of December 31, 2017 and 2016 : Weighted Average Effective December 31, December 31, 2017 2016 (In thousands) Variable rate (1) 4.40% $ 534,500 $ 31,000 Fixed rate (2) 3.79% 657,701 273,000 Unconsolidated real estate ventures - mortgages payable 1,192,201 304,000 Unamortized deferred financing costs (2,000 ) (1,034 ) Unconsolidated real estate ventures - mortgages payable, net (3) $ 1,190,201 $ 302,966 ______________ (1) Includes variable rate mortgages payable with interest rate cap agreements. (2) Includes variable rate mortgages payable with interest rates fixed by interest rate swap agreements. (3) See Note 17 for additional information regarding related commitments and contingencies. The following is a summary of the financial information for our unconsolidated real estate ventures as of December 31, 2017 and 2016 and for each of the three years in the period ended December 31, 2017 : December 31, 2017 2016 Combined balance sheet information: (In thousands) Real estate, net $ 2,106,670 $ 463,643 Other assets 264,731 134,596 Total assets $ 2,371,401 $ 598,239 Mortgages payable, net $ 1,190,202 $ 302,966 Other liabilities 76,415 24,896 Total liabilities 1,266,617 327,862 Noncontrolling interests — 343 Total equity 1,104,784 270,034 Total liabilities and equity $ 2,371,401 $ 598,239 Year Ended December 31, 2017 2016 2015 Combined income statement information: (In thousands) Total revenue $ 135,256 $ 68,118 $ 67,275 Operating income 14,741 19,283 21,173 Net income (loss) (7,593 ) 5,234 340

Variable Interest Entities

Variable Interest Entities	12 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Variable Interest Entities	Variable Interest Entities Unconsolidated VIEs As of December 31, 2017 and 2016 , we have interests in entities that are deemed VIEs that are in development stage and do not hold sufficient equity at risk or conduct substantially all their operations on behalf of the 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 December 31, 2017 and 2016 , the net carrying amounts of our investment in these entities were $163.5 million and $42.4 million . Our maximum exposure to loss in these entities is limited to our investments, construction commitments and debt guarantees. See Note 17 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 either substantive liquidation rights, or 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. We also consolidate certain VIEs that have minimal noncontrolling interests (less than 5%). These entities are VIEs because the noncontrolling interest holders do not have substantive kick-out or participating rights. We consolidate these entities because we control all of their significant business activities. As of December 31, 2017 , the total assets and liabilities of such consolidated VIEs, excluding the operating partnership, were approximately $111.0 million and $8.8 million .

Other Assets, Net

Other Assets, Net	12 Months Ended
	Dec. 31, 2017
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Other Assets, Net	Other Assets, Net The following is a summary of other assets, net as of December 31, 2017 and 2016 : December 31, 2017 2016 (In thousands) Deferred leasing costs $ 171,153 $ 157,258 Accumulated amortization (67,180 ) (57,910 ) Deferred leasing costs, net 103,973 99,348 Prepaid expenses 9,038 2,199 Identified intangible assets, net 126,467 3,063 Deferred financing costs on revolving credit facility, net 6,654 — Deposits 6,317 100 Other 11,474 8,245 Total other assets, net $ 263,923 $ 112,955 The following is a summary of the composition of identified intangible assets, net as of December 31, 2017 and 2016 : December 31, 2017 2016 Identified intangible assets: (in thousands) In-place leases $ 72,086 $ 12,777 Above-market real estate leases 12,066 773 Below-market ground leases 2,547 2,215 Option to enter into ground lease 17,090 — Management and leasing contracts 48,900 — Other 206 206 Total identified intangibles assets 152,895 15,971 Accumulated amortization: In-place leases 20,015 10,871 Above-market real estate leases 1,600 612 Below-market ground leases 1,365 1,278 Option to enter into ground lease 78 — Management and leasing contracts 3,209 — Other 161 147 Total accumulated amortization 26,428 12,908 Identified intangible assets, net $ 126,467 $ 3,063 The following is a summary of amortization expense included in the statements of operations related to identified intangible assets for each of the three years in the period ended December 31, 2017 : Year Ended December 31, 2017 2016 2015 (in thousands) In-place lease amortization (1) $ 10,216 $ 485 $ 1,343 Above-market real estate lease amortization (2) 1,428 78 89 Below-market ground lease amortization (3) 87 85 85 Management and leasing contract amortization (1) 3,209 — — Other amortization (1) 14 92 248 Total identified intangible asset amortization $ 14,954 $ 740 $ 1,765 ___________________________________________ (1) Amounts are included in "Depreciation and amortization expenses" in our statements of operations. (2) Amounts are included in "Property rentals revenue" in our statements of operations. (3) Amounts are included in "Property operating expenses" in our statements of operations. As of December 31, 2017 , the estimated amortization of identified intangible assets is as follows for the next five years and thereafter: Year ending December 31, Amount (in thousands) 2018 $ 22,338 2019 19,167 2020 16,136 2021 12,607 2022 11,248 Thereafter 44,971 Total $ 126,467

Debt

Debt	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Debt	Debt Mortgages Payable The following is a summary of mortgages payable as of December 31, 2017 and 2016 : Weighted Average December 31, December 31, 2017 (1) 2016 (In thousands) Variable rate (2) 3.62% $ 498,253 $ 547,291 Fixed rate (3) 4.25% 1,537,706 620,327 Mortgages payable 2,035,959 1,167,618 Unamortized deferred financing costs and premium/discount, net (10,267 ) (2,604 ) Mortgages payable, net $ 2,025,692 $ 1,165,014 Payable to former parent (4) — $ — $ 283,232 __________________________ (1) Includes mortgages payable assumed in the Combination. See Note 3 for additional information. (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) Includes amounts payable to former parent as of December 31, 2016 in connection with the Bowen Building and The Bartlett. See Note 18 for additional information. As of December 31, 2017 , the net carrying value of real estate collateralizing our mortgages payable totaled $2.9 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 December 31, 2017 , we were not in default under any mortgage loan. In the Combination, we assumed mortgages payable with an aggregate principal balance of $768.5 million . In addition, we entered into mortgages payable with an aggregate principal balance of $79.3 million during the year ended December 31, 2017 with an ability to draw an additional $143.7 million for construction. During the year ended December 31, 2017 , we repaid mortgages payable with an aggregate principal balance of $250.0 million , which includes mortgages payable totaling $64.8 million assumed in the Combination. We recognized losses on the extinguishment of debt in conjunction with these repayments of $701,000 for the year ended December 31, 2017 . As of December 31, 2017 , we had various interest rate swap and cap agreements with an aggregate notional value of $1.4 billion to swap variable interest rates to fixed rates on certain of our mortgages payable. See Note 15 for additional information. Credit Facility On July 18, 2017, we entered into 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 . The interest rate for the credit facility varies based on a ratio of our total outstanding indebtedness to a valuation of certain real property and assets and ranges (a) in the case of the revolving credit facility, from LIBOR plus 1.10% to LIBOR plus 1.50% , (b) in the case of the Tranche A-1 Term Loan, from LIBOR plus 1.20% to LIBOR plus 1.70% and (c) in the case of the Tranche A-2 Term Loan, from LIBOR plus 1.55% to LIBOR plus 2.35% . There are various LIBOR options in the credit facility, and we elected the one-month LIBOR option as of December 31, 2017 . In October 2017, we entered into an interest rate swap with a notional value of $50.0 million to convert the variable interest rate applicable to our Tranche A-1 Term Loan to a fixed interest rate, providing a base interest rate under the facility agreement of 1.97% per annum. The interest rate swap matures in January 2023, concurrent with the maturity of our Tranche A-1 Term Loan. As of December 31, 2017 , we were not in default under our credit facility. On July 18, 2017, in connection with the Combination, we drew $115.8 million on the revolving credit facility and $50.0 million under the Tranche A-1 Term Loan. In connection with the execution of the credit facility, we incurred $11.2 million in debt issuance costs. The following is a summary of amounts outstanding under the credit facility as of December 31, 2017 : December 31, 2017 Interest Rate Balance (In thousands) Revolving credit facility (1) 2.66% $ 115,751 Tranche A-1 Term Loan 3.17% $ 50,000 Unamortized deferred financing costs, net (3,463 ) Unsecured term loan, net $ 46,537 __________________________ (1) As of December 31, 2017 , letters of credit with an aggregate face amount of $5.7 million were provided under our revolving credit facility. Principal Maturities Principal maturities of debt outstanding as of December 31, 2017 , including mortgages payable, the Tranche A-1 Term Loan and borrowings on the revolving credit facility, are as follows: Year ending December 31, Amount (In thousands) 2018 $ 337,513 2019 227,041 2020 225,914 2021 216,545 2022 327,500 Thereafter 867,197 Total $ 2,201,710 Interest costs incurred, excluding amortization and accretion of discounts and premiums and deferred financing costs, were $65.4 million , $54.3 million and $55.5 million for each of the three years in the period ended December 31, 2017 , of which $12.7 million , $4.1 million and $6.4 million were capitalized.

Other Liabilities, Net

Other Liabilities, Net	12 Months Ended
	Dec. 31, 2017
Other Liabilities Disclosure [Abstract]
Other Liabilities, Net	Other Liabilities, Net The following is a summary of other liabilities, net as of December 31, 2017 and 2016 : December 31, 2017 2016 (In thousands) Lease intangible liabilities $ 44,917 $ 36,515 Accumulated amortization (26,950 ) (24,945 ) Lease intangible liabilities, net 17,967 11,570 Prepaid rent 15,751 9,163 Lease assumption liabilities and accrued tenant incentives (1) 50,866 14,907 Capital lease obligation 15,819 — Security deposits 13,618 10,324 Ground lease deferred rent payable 3,730 3,331 Net deferred tax liability 8,202 — Dividends payable (2) 31,097 — Other 4,227 192 Total other liabilities, net $ 161,277 $ 49,487 ___________________________________________ (1) As of December 31, 2017 , includes $43.4 million of lease assumption liabilities assumed in the Combination. See Note 3 for additional information. (2) Dividends declared in December 2017 that were paid in January 2018. Amortization expense included in "Property rentals" the statements of operations related to lease intangible liabilities for each of the three years in the period ended December 31, 2017 was $2.3 million , $1.4 million and $2.9 million . As of December 31, 2017 , the estimated amortization of lease intangible liabilities is as follows for the next five years and thereafter: Year ending December 31, Amount (in thousands) 2018 $ 2,695 2019 2,633 2020 2,382 2021 1,905 2022 1,788 Thereafter 6,564 Total $ 17,967

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes For the year ended December 31, 2017 , we intend to elect to be taxed as a REIT, and our former parent also elected to be taxed as a REIT for the years ended December 31, 2016 and 2015 . Accordingly, we incurred no federal income tax expense for each of the three years ended December 31, 2017 related to our REIT subsidiaries. The only federal income taxes included in the accompanying financial statements relate to activities of our TRSs. Due to the passage of federal tax reform legislation, which was signed into law on December 22, 2017 and which we refer as the 2017 Tax Act, our TRSs were required to decrease the net deferred tax liability, which resulted in a net tax benefit of $3.9 million during the year ended December 31, 2017 . The remainder of the tax benefit is due to the net loss of the TRSs. Our financial statements include the operations of our TRSs, which are subject to federal, state and local income taxes on their taxable income. As a REIT, we may also be subject to federal excise taxes if we engage in certain types of transactions. Continued qualification as a REIT depends on our ability to satisfy the REIT distribution tests, stock ownership requirements and various other qualification tests. As of December 31, 2017 , our TRSs have an estimated federal and state net operating loss of $6.2 million , which will expire in 2037 . As of December 31, 2017 , the cost of real estate, net of accumulated depreciation, for federal income tax purposes was approximately $3.5 billion . The following is a summary of our income tax benefit (expense) for each of the three years in the period ended December 31, 2017 : Year Ended December 31, 2017 2016 2015 (in thousands) Current tax benefit (expense) $ (496 ) $ (1,083 ) $ (420 ) Deferred tax benefit (expense) 10,408 — — Income tax benefit (expense) $ 9,912 $ (1,083 ) $ (420 ) As of December 31, 2017 , we have a net deferred tax liability of $8.2 million primarily related to the management and leasing contracts assumed in the Combination, partially offset by deferred tax assets associated with tax versus book differences, related general and administrative expenses and the net operating loss for 2017 . We are subject to federal, state and local income tax examinations by taxing authorities for 2014 through 2017. December 31, 2017 2016 (in thousands) Deferred tax assets: Accrued bonus $ 1,675 $ — Net operating loss 1,710 — Other 805 — Total deferred tax assets 4,190 — Deferred tax liabilities: Management and leasing contracts (11,840 ) — Other (552 ) — Total deferred tax liabilities (12,392 ) — Net deferred tax liability $ (8,202 ) $ — During the year ended December 31, 2017 , our Board of Trustees declared cash dividends of $0.45 per common share of which $0.31 was taxable as ordinary income for federal income tax purposes in 2017 and the remaining $0.14 will be determined in 2018. No dividends were declared or paid in 2016 and 2015.

Redeemable Noncontrolling Inter

Redeemable Noncontrolling Interests	12 Months Ended
	Dec. 31, 2017
Noncontrolling Interest [Abstract]
Redeemable Noncontrolling Interests	Redeemable Noncontrolling Interests JBG SMITH LP In the Formation Transaction, JBG SMITH LP issued 19.8 million OP Units to persons other than JBG SMITH that are redeemable for cash or our common shares beginning August 1, 2018, subject to certain limitations. These OP Units represent a 14.4% interest in JBG SMITH LP as of December 31, 2017 . The carrying amount of the redeemable noncontrolling interests is adjusted to its redemption value at the end of each reporting period, but no less than its initial 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 In November 2017, a real estate venture acquired 965 Florida Avenue for $1.5 million and concurrently restructured the terms of the venture. Prior to the restructure, our partner held a 37.9% ownership interest. Pursuant to the terms of the venture agreement, we will fund all capital contributions until we achieve a 97.0% interest. Our partner can redeem its interest for cash two years after delivery, but no later than seven years subsequent to delivery. As of December 31, 2017 , we held a 67.6% ownership interest and consolidated 965 Florida Avenue. Below is a summary of the activity of redeemable noncontrolling interests for the year ended December 31, 2017 : JBG SMITH LP Consolidated Real Estate Venture Total (In thousands) Balance at January 1, 2017 (1) $ — $ — $ — OP Units issued at the Separation 96,632 — 96,632 OP Units issued in connection with the Combination (2) 359,967 — 359,967 Net loss attributable to redeemable noncontrolling interests (7,320 ) (8 ) (7,328 ) Other comprehensive income 225 — 225 Distributions and acquisition of consolidated real estate venture (9,113 ) 5,420 (3,693 ) Share-based compensation expense 32,634 — 32,634 Adjustment to redemption value 130,692 — 130,692 Balance as of December 31, 2017 $ 603,717 $ 5,412 $ 609,129 __________________ (1) We did not have any redeemable noncontrolling interests prior to the Separation on July 17, 2017. (2) Excludes certain OP Units issued in the Combination which have an estimated fair value of $ 110.6 million , that are subject to post-combination employment with vesting over periods of either 12 or 60 months. See Note 12 for additional information.

Share-Based Payments and Employ

Share-Based Payments and Employee Benefits	12 Months Ended
	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-Based Payments and Employee Benefits	Share-Based Payments and Employee Benefits OP UNITS In the Combination, 3.3 million OP Units were issued with an estimated grant-date fair value of $ 110.6 million , subject to post-combination employment with vesting over periods of either 12 or 60 months. The fair value of these OP Units was estimated based on the post-vesting restriction periods of the OP Units. The significant assumptions used to value the OP Units included expected volatilities ( 18.0% to 27.0% ), risk-free interest rates ( 1.3% to 1.5% ) and post-vesting restriction periods ( 1 year to 3 years ). Compensation expense for these OP Units is recognized over the graded vesting period. See Note 3 for additional information. The following table presents information regarding the OP Units activity during the year ended December 31, 2017 : Unvested Shares Weighted Average Grant-Date Fair Value Unvested at January 1, 2017 — $ — Granted 3,280,900 33.71 Vested (193,938 ) 37.10 Unvested at December 31, 2017 3,086,962 33.49 JBG SMITH 2017 Omnibus Share Plan On June 23, 2017, our Board of Trustees adopted the JBG SMITH 2017 Omnibus Share Plan (the "Plan"), effective as of July 17, 2017, and authorized the reservation of approximately 10.3 million of our common shares pursuant to the Plan. On July 10, 2017, our then sole-shareholder approved the Plan. As of December 31, 2017 , there were 6.6 million common shares available for issuance under the Plan. Formation Awards Pursuant to the Plan, on July 18, 2017, we granted approximately 2.7 million Formation Awards based on an aggregate notional value of approximately $100.0 million divided by the volume-weighted average price on July 18, 2017 of $37.10 per common share. The Formation Awards are structured in the form of profits interests in JBG SMITH LP that provide for a share of appreciation determined by the increase in the value of a common share at the time of conversion over the $37.10 volume-weighted average price of a common share at the time the formation unit was granted. The Formation Awards, subject to certain conditions, generally vest 25% on each of the third and fourth anniversaries and 50% on the fifth anniversary, of the closing of the Combination, subject to continued employment with JBG SMITH through each vesting date. The value of vested Formation Awards is realized through conversion of the award into a number of LTIP Units, and subsequent conversion into a number of OP Units determined based on the difference between $37.10 and the value of a common share on the conversion date. The conversion ratio between Formation Awards and OP Units, which starts at zero, is the quotient of (i) the excess of the value of a common share on the conversion date above the per share value at the time the Formation Award was granted over (ii) the value of a common share as of the date of conversion. This is similar to a "cashless exercise" of stock options, whereby the holder receives a number of shares equal in value to the difference between the full value of the total number of shares for which the option is being exercised and the total exercise price. Like options, Formation Awards have a finite 10 -year term over which their value is allowed to increase and during which they may be converted into LTIP Units (and in turn, OP Units). Holders of Formation Awards will not receive distributions or allocations of net income or net loss prior to vesting and conversion to LTIP Units. The grant-date fair value of the Formation Awards was $23.7 million or $8.84 per unit estimated using Monte Carlo simulations. The significant assumptions used to value the awards included expected volatility ( 26.0% ), dividend yield ( 2.3% ), risk-free interest rate ( 2.3% ) and expected life ( 7 years ). Compensation expense for these awards is being recognized over a five -year period. The following table presents information regarding the Formation Awards activity during the year ended December 31, 2017 : Unvested Shares Weighted Average Grant-Date Fair Value Unvested at January 1, 2017 — $ — Granted 2,680,552 8.84 Forfeited (6,738 ) 8.84 Unvested at December 31, 2017 2,673,814 8.84 LTIP and Time-Based LTIP Units On July 18, 2017, we granted a total of 47,166 fully vested LTIP Units to the seven non-employee trustees in the notional amount of $250,000 each. The LTIP Units may not be sold while such non-employee trustee is serving on the Board. On the same date, we also granted 59,927 LTIP units to a key employee of which 50% vested immediately and the remaining 50% vests ratably from the 31 st to the 60 th month following the grant date. These LTIP Units had an aggregate grant-date fair value of $3.5 million . On August 1, 2017, we granted 302,518 Time-Based LTIP Units to management and other employees under our Plan. The Time-Based LTIP units vest in four equal installments on August 1 of each year, subject to continued employment. These Time-Based LTIP Units were valued at a weighted average grant-date fair value of $33.71 per unit. Compensation expense for these units is being recognized over a four -year period. The fair value of LTIP and Time-Based LTIP Units was estimated based on the post-vesting restriction periods. The significant assumptions used to value the units included expected volatilities ( 17.0% to 19.0% ), risk-free interest rates ( 1.3% to 1.5% ) and post-vesting restriction periods ( 2 years to 3 years ). Net income and net loss is allocated to each LTIP and Time-Based LTIP Unit. LTIP and Time-Based LTIP Unit holders have the right to convert all or a portion of vested units into OP Units, which are then subsequently exchangeable for our common shares. LTIP and Time-Based LTIP Units do not have redemption rights, but any OP Units into which units are converted are entitled to redemption rights. LTIP and Time-Based LTIP Units, generally, vote with the OP Units and do not have any separate voting rights except in connection with actions that would materially and adversely affect the rights of the LTIP and Time-Based LTIP Units. The following table presents information regarding the LTIP and Time-Based LTIP Units activity during the year ended December 31, 2017 : Unvested Shares Weighted Average Grant-Date Fair Value Unvested at January 1, 2017 — $ — Granted 409,611 33.41 Vested (77,129 ) 32.26 Forfeited (275 ) 33.71 Unvested at December 31, 2017 332,207 33.68 Performance-Based LTIP Units On August 1, 2017, we granted 605,072 Performance-Based LTIP Units to management and other employees under the Plan. Performance-Based LTIP Units are performance-based equity compensation pursuant to which participants have the opportunity to earn Performance-Based LTIP Units based on the relative performance of the total shareholder return ("TSR") of our common shares compared to the companies in the FTSE NAREIT Equity Office Index, over the three -year performance period beginning on the August 1, 2017 grant date, inclusive of dividends and stock price appreciation. 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. Net income and net loss are allocated to each Performance-Based LTIP Unit. The grant-date fair value of the Performance-Based LTIP Units was $9.7 million or $15.95 per unit estimated using Monte Carlo simulations. The significant assumptions used to value the Performance-Based LTIP Units include expected volatility ( 18.0% ), dividend yield ( 2.3% ) and risk-free interest rates ( 1.5% ). Compensation expense for these units is being recognized over a four -year period. The following table presents information regarding the Performance-Based LTIP Units activity during the year ended December 31, 2017 : Unvested Shares Weighted Average Grant-Date Fair Value Unvested at January 1, 2017 — $ — Granted 605,072 15.95 Forfeited (550 ) 15.95 Unvested at December 31, 2017 604,522 15.95 Share-Based Compensation Expense Share-based compensation expense for each of the three years in the period ended December 31, 2017 is summarized as follows: Year Ended December 31, 2017 2016 2015 (In thousands) Formation Awards $ 5,169 $ — $ — LTIP Units 2,615 — — OP Units (1) 21,467 — — Share-based compensation related to Formation Transaction (2) 29,251 — — Time-Based LTIP Units that vest over four years 2,211 — — Performance-Based LTIP Units 1,172 — — Other equity awards (3) 1,526 4,502 4,506 Share-based compensation expense - other (4) 4,909 4,502 4,506 Total share-based compensation expense 34,160 4,502 4,506 Less amount capitalized (467 ) — — Net share-based compensation expense $ 33,693 $ 4,502 $ 4,506 ______________________________________________ (1) Represents share-based compensation expense for OP Units subject to post-combination employment. See Note 3 for additional information. (2) Included in "General and administrative expense: Share-based compensation related to Formation Transaction" in the accompanying statements of operations. (3) Represents share-based compensation expense related to equity awards prior to the Formation Transaction. (4) Included in "General and administrative expense" in the accompanying statements of operations. As of December 31, 2017 , we had $124.9 million of total unrecognized compensation expense related to unvested share-based payment arrangements (unvested OP Units, Formation Awards, Time-Based LTIP Units and Performance-Based LTIP Units). This expense is expected to be recognized over a weighted average period of 3.3 years. Employee Benefits We have a 401(k) defined contribution plan (the "401(k) Plan") covering substantially all of our officers and employees which permits participants to defer compensation up to the maximum amount permitted by law. We provide a discretionary matching contribution. Employees’ contributions vest immediately and our matching contributions vest over five years. Our contributions for each of the three years in the period ended December 31, 2017 were $3.6 million , $2.4 million , $2.3 million .

Earnings (Loss) Per Common Shar

Earnings (Loss) Per Common Share	12 Months Ended
	Dec. 31, 2017
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) available to common shareholders used in calculating basic and diluted earnings (loss) per common share for each of the three years in the period ended December 31, 2017 : Year Ended December 31, 2017 2016 2015 (In thousands, except per share amounts) Net income (loss) $ (79,084 ) $ 61,974 $ 49,628 Net loss attributable to redeemable noncontrolling interests 7,328 — — Net loss attributable to noncontrolling interest 3 — — Net income (loss) attributable to common shareholders (71,753 ) 61,974 49,628 Distributions to participating securities (1,655 ) — — Net income (loss) available to common shareholders $ (73,408 ) $ 61,974 $ 49,628 Weighted average number of common shares outstanding — basic and diluted (1) 105,359 100,571 100,571 Earnings (loss) per common share: Basic $ (0.70 ) $ 0.62 $ 0.49 Diluted (0.70 ) 0.62 0.49 ______________ (1) Reflects the weighted average common shares outstanding as of the date of the Separation in all periods prior to July 17, 2017. The effect of the conversion of 16.7 million OP Units that were outstanding at December 31, 2017 is excluded in the computation of basic and diluted loss per common share, as the assumed exchange of such units for common shares on a one-for-one basis was antidilutive (the assumed conversion of these units would have no net impact on the determination of diluted earnings per share). Since vested and outstanding OP Units, which are held by noncontrolling interests, are attributed gains and losses at an identical proportion to the common shareholders, the gains and losses attributable and their equivalent weighted average OP Unit impact are excluded from net income (loss) available to common shareholders and the weighted average number of common shares outstanding in calculating basic and diluted loss per common share. The number of additional securities excluded from the calculation of diluted earnings (loss) per common share as they were antidilutive, but potentially could be dilutive in the future are included in the following table for each of the three years in the period ended December 31, 2017 : Year Ended December 31, 2017 2016 2015 (In thousands) OP Units 3,087 — — Formation Awards 2,674 — — Time-Based LTIP Units 409 — — Performance-Based LTIP Units 605 — —

Future Minimum Rental Income

Future Minimum Rental Income	12 Months Ended
	Dec. 31, 2017
Leases [Abstract]
Future Minimum Rental Income	Future Minimum Rental Income We lease space to tenants under operating leases that expire at various dates through the year 2036. The leases provide for the payment of fixed base rents payable monthly in advance as well as reimbursements of real estate taxes, insurance and maintenance costs. Retail leases may also provide for the payment by the lessee of additional rents based on a percentage of their sales. As of December 31, 2017 , future base rental revenue under these non-cancelable operating leases excluding extension options is as follows: Year ending December 31, Amount (In thousands) 2018 $ 428,413 2019 341,872 2020 307,181 2021 264,351 2022 226,490 Thereafter 1,167,008

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis As of December 31, 2017 , we had various derivative financial instruments consisting of interest rate swap and cap agreements that are measured at fair value on a recurring basis. There were no derivative financial instruments prior to the Combination. The net unrealized gain on our derivative financial instruments designated as cash flow hedges was $1.8 million for the year ended December 31, 2017 and is recorded in "Accumulated other comprehensive income" in the balance sheet. Within the next 12 months, we expect to reclassify $3.6 million as an increase to interest expense. The net unrealized gain on our derivative financial instruments not designated as cash flow hedges was $1.3 million for the year ended December 31, 2017 and is recorded in "Interest expense" in the statement of operations. 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 as of December 31, 2017 : Fair Value Measurements Total Level 1 Level 2 Level 3 December 31, 2017 (In thousands) Derivative financial instruments designated as cash flow hedges: Classified as assets in "Other assets, net" $ 1,506 $ — $ 1,506 $ — Classified as liabilities in "Other liabilities, net" 2,640 — 2,640 — Derivative financial instruments not designated as cash flow hedges: Classified as assets in "Other assets, net" $ 635 $ — $ 635 $ — Classified as liabilities in "Other liabilities, net" $ 22 $ — $ 22 $ — 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 December 31, 2017 , 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 gain'' was primarily attributable to the net change in unrealized gains or losses related to the interest rate swaps that were outstanding as of December 31, 2017 , none of which were reported in the statements of operations because they were documented and qualified as hedging instruments and there was no ineffectiveness in relation to the hedges. Financial Assets and Liabilities Not Measured at Fair Value As of December 31, 2017 and 2016 , 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: December 31, 2017 December 31, 2016 Carrying Amount (1) Fair Value Carrying Amount (1) Fair Value (In thousands) Financial liabilities: Mortgages payable $ 2,035,959 $ 2,060,899 $ 1,167,618 $ 1,192,267 Revolving credit facility 115,751 115,768 — — Unsecured term loan 50,000 50,029 — — ______________________________________ ( 1) The carrying amount consists of principal only. The fair value of our mortgages payable is estimated by discounting the future contractual cash flows of these instruments using current risk-adjusted rates available to borrowers with similar credit ratings, which are provided by a third-party specialist. The fair value of the mortgages payable and unsecured term loan was determined using Level 2 inputs of the fair value hierarchy. The fair value of our revolving credit facility and unsecured term loan is calculated based on the net present value of payments over the term of the facilities using estimated market rates for similar notes and remaining terms. The fair value of the revolving credit facility and unsecured term loan was determined using Level 2 inputs of the fair value hierarchy.

Segment Information

Segment Information	12 Months Ended
	Dec. 31, 2017
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 a result of the Formation Transaction, we redefined our reportable segments to be aligned with our 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 (office, multifamily, and third-party real estate services) based on the economic characteristics and nature of our assets and services. In connection therewith, we have reclassified the prior period segment financial data to conform to the current period presentation. The CODM measures and evaluates the performance of our operating segments, with the exception of the third-party real estate services business, based on the net operating income ("NOI") of properties within each segment. NOI includes property rental revenues and tenant reimbursements and deducts property operating expenses and real estate taxes. With respect to the third-party 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 $45.7 million classified in "Other assets, net" in the balance sheet as of December 31, 2017 . Consistent with internal reporting presented to our CODM and our definition of NOI, the third-party real estate services operating results are excluded from the NOI data below. The following table reflects the reconciliation of net income (loss) attributable common shareholders to consolidated NOI for each of the three years in the period ended December 31, 2017 : Year Ended December 31, 2017 2016 2015 (In thousands) Net income (loss) attributable to common shareholders $ (71,753 ) $ 61,974 $ 49,628 Add: Depreciation and amortization expense 161,659 133,343 144,984 General and administrative expense: Corporate and other 47,131 48,753 44,424 Third-party real estate services 51,919 19,066 18,217 Share-based compensation related to Formation Transaction 29,251 — — Transaction and other costs 127,739 6,476 — Interest expense 58,141 51,781 50,823 Loss on extinguishment of debt 701 — — Income tax expense (benefit) (9,912 ) 1,083 420 Less: Third-party real estate services, including reimbursements 63,236 33,882 29,467 Other income 5,167 5,381 10,854 Loss from unconsolidated real estate ventures, net (4,143 ) (947 ) (4,283 ) Interest and other income (loss), net 1,788 2,992 2,557 Gain on bargain purchase 24,376 — — Net loss attributable to redeemable noncontrolling interests 7,328 — — Net loss attributable to noncontrolling interest 3 — — Consolidated NOI $ 297,121 $ 281,168 $ 269,901 Below is a summary of NOI by segment for each of the three years in the period ended December 31, 2017 : Year Ended December 31, 2017 Office Multifamily Other Elimination of Intersegment Activity Total (In thousands) Rental revenue: Property rentals $ 343,213 $ 85,809 $ 10,508 $ (2,905 ) $ 436,625 Tenant reimbursements 32,315 5,012 658 — 37,985 Total rental revenue 375,528 90,821 11,166 (2,905 ) 474,610 Rental expense: — Property operating 93,834 24,297 8,528 (15,604 ) 111,055 Real estate taxes 50,483 10,940 5,011 — 66,434 Total rental expense 144,317 35,237 13,539 (15,604 ) 177,489 Consolidated NOI $ 231,211 $ 55,584 $ (2,373 ) $ 12,699 $ 297,121 Year Ended December 31, 2016 Office Multifamily Other Elimination of Intersegment Activity Total (In thousands) Rental revenue: Property rentals $ 317,956 $ 63,401 $ 23,234 $ (2,996 ) $ 401,595 Tenant reimbursements 33,361 3,454 846 — 37,661 Total rental revenue 351,317 66,855 24,080 (2,996 ) 439,256 Rental expense: — Property operating 91,128 17,238 7,216 (15,278 ) 100,304 Real estate taxes 46,115 6,993 4,676 — 57,784 Total rental expense 137,243 24,231 11,892 (15,278 ) 158,088 Consolidated NOI $ 214,074 $ 42,624 $ 12,188 $ 12,282 $ 281,168 Year Ended December 31, 2015 Office Multifamily Other Elimination of Intersegment Activity Total (In thousands) Rental revenue: Property rentals $ 311,671 $ 53,071 $ 27,504 $ (2,436 ) $ 389,810 Tenant reimbursements 35,508 2,790 2,178 — 40,476 Total rental revenue 347,179 55,861 29,682 (2,436 ) 430,286 Rental expense: Property operating 92,355 14,606 9,268 (14,718 ) 101,511 Real estate taxes 45,479 6,022 7,373 — 58,874 Total rental expense 137,834 20,628 16,641 (14,718 ) 160,385 Consolidated NOI $ 209,345 $ 35,233 $ 13,041 $ 12,282 $ 269,901 The following is a summary of certain balance sheet data by segment as of December 31, 2017 and 2016 : Office Multifamily Other Elimination of Intersegment Activity Total December 31, 2017 (In thousands) Real estate, at cost $ 3,955,013 $ 1,476,423 $ 594,361 $ — $ 6,025,797 Investments in and advances to unconsolidated real estate ventures 124,659 98,835 38,317 — 261,811 Total assets 3,542,977 1,434,999 1,299,085 (205,254 ) 6,071,807 December 31, 2016 Real estate, at cost $ 2,798,946 $ 959,404 $ 397,041 $ — $ 4,155,391 Investments in and advances to 45,647 — 129 — 45,776 Total assets 2,388,396 873,157 399,087 — 3,660,640

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2017
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 December 31, 2017 , we have construction in progress that will require an additional $766.0 million to complete ( $676.0 million related to our consolidated entities and $90.0 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, 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. 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, 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 the guarantee. Amounts that may be required to be paid in future periods in relation to budget overruns or operating losses that 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. As of December 31, 2017 , the aggregate amount of our principal payment guarantees was approximately $91.5 million for our consolidated entities and $31.0 million for our unconsolidated real estate ventures. As of December 31, 2017 , we expect to fund additional capital to certain of our unconsolidated investments totaling approximately $49.3 million , which we anticipate will be primarily expended over the next two to three years. In connection with the Formation Transaction, we entered into 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. We are obligated under non-cancelable operating leases including ground leases on certain of our properties through 2106. As of December 31, 2017 , future minimum rental payments under non-cancelable operating leases, capital leases and lease assumption liabilities are as follows: Year ending December 31, Amount (In thousands) 2018 $ 13,686 2019 14,073 2020 13,866 2021 13,594 2022 12,845 Thereafter 697,903 Total $ 765,967 During each of the three years in the period ended December 31, 2017 , we recognized approximately $4.7 million , $2.1 million and $1.9 million of rental expense related to our non-cancelable operating and capital leases.

Transactions with Vornado and R

Transactions with Vornado and Related Parties	12 Months Ended
	Dec. 31, 2017
Related Party Transactions [Abstract]
Transactions with Vornado and Related Parties	Transactions with Vornado and Related Parties Transactions with Vornado As described in Note 1 and Note 3, the accompanying financial statements present the operations of the Vornado Included Assets as carved-out from the financial statements of Vornado for all periods prior to July 17, 2017. Certain centralized corporate costs borne by Vornado for management and other services including, but not limited to, accounting, reporting, legal, tax, information technology and human resources have been allocated to the assets in the financial statements based on either actual costs incurred or a proportion of costs estimated to be applicable to the Vornado Included Assets based on key metrics including total revenue. The total amounts allocated during each of the three years in the period ended December 31, 2017 were $13.0 million , $20.7 million and $20.0 million . These allocated amounts are included as a component of "General and administrative expense: Corporate and other" expenses on the statements of operations and do not necessarily reflect what actual costs would have been if the Vornado Included Assets were a separate standalone public company. Actual costs may be materially different. In connection with the Formation Transaction, we entered into an agreement with Vornado under which Vornado provides operational support for an initial period of up to two years. These services include information technology, financial reporting and payroll services. The charges for these services are based on an hourly or per transaction fee arrangement including reimbursement for overhead and out-of-pocket expenses. The total charges for the year ended December 31, 2017 were approximately $2.2 million . Pursuant to an agreement, 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 year ended December 31, 2017 was $779,000 . We believe that the terms of both of these agreements are comparable to those that would have been negotiated based on market rates. In connection with the Formation Transaction, we entered into a Tax Matters Agreement with Vornado. See Note 17 for additional information. In August 2014, we completed a $185.0 million financing of the Universal buildings, a 687,000 square foot office complex located in Washington, DC. In connection with this financing, pursuant to a note agreement dated August 12, 2014, we used a portion of the financing proceeds and made an $86.0 million loan to Vornado at LIBOR plus 2.9% due August 2019. During 2016 and 2015, Vornado repaid $4.0 million and $7.0 million of the loan receivable. At the Separation, Vornado repaid the outstanding balance of the loan and related accrued interest. As of December 31, 2016 , the balance of the receivable from Vornado, including accrued interest, was $75.1 million . We recognized interest income of $1.8 million , $3.3 million and $3.0 million during each of the three years in the period ended December 31, 2017 . In connection with the development of The Bartlett, prior to the Combination, we entered into various note agreements with Vornado whereby we could borrow up to a maximum of $170.0 million . Vornado contributed these note agreements along with accrued and unpaid interest to JBG SMITH at the Separation. As of December 31, 2016 , the amounts outstanding under these note agreements totaled $166.5 million , and are included in "Payable to former parent" on our balance sheets. We incurred interest expense of $4.1 million , $4.1 million and $846,000 during each of the three years in the period ended December 31, 2017 . In June 2016, the $115.0 million mortgage loan (including $608,000 of accrued interest) secured by the Bowen Building, a 231,000 square foot office building located in Washington, DC, was repaid with the proceeds of a $115.6 million draw on our former parent's revolving credit facility. Given that the $115.6 million draw on our former parent's credit facility was secured by an interest in the property, such amount was included in "Payable to former parent" in our balance sheet as of December 31, 2016 . The loan was repaid with amounts drawn under our revolving credit facility. See Note 8 for additional information. We incurred interest expense of $1.3 million and $1.1 million during the two years in the period ended December 31, 2017 . 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 $13.6 million , $12.1 million and $12.4 million during each of the three years in the period ended December 31, 2017 , which are included in "Property operating expenses" in our statements of operations. We entered into a consulting agreement with Mr. Schear, a member of our Board of Trustees and formerly the president of Vornado’s Washington, DC segment. The consulting agreement expired on December 31, 2017 and provides for the payment of consulting fees and expenses at the rate of approximately $ 169,400 per month for the 24 months following the Separation, including after the termination of the consulting agreement. The amount due under this consulting agreement of $4.1 million was expensed in connection with the Combination during the year ended December 31, 2017 . As of December 31, 2017 , the remaining liability is $3.0 million . Additionally, in March 2017, Vornado amended Mr. Schear’s employment agreement to provide for the payment of severance, bonus and post-employment services. A total of $16.4 million was expensed in connection with the Separation during the year ended December 31, 2017 . Transactions with Real Estate Ventures In addition, we have a third-party real estate services business that provides fee-based real estate services to the JBG Legacy Funds and other third parties. 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 year ended December 31, 2017 was $19.9 million . We rent our corporate offices from an unconsolidated real estate venture and incurred $2.3 million during the year ended December 31, 2017 , which is recorded in "General and administrative expense: Corporate and other" in our statement of operations. Registration Rights Agreements In connection with the Formation Transaction, we entered into a registration rights agreement with certain former investors in the legacy JBG funds that received our common shares in the Formation Transaction (the "Shares Registration Rights Agreement") and a separate registration rights agreement with the certain former investors in the legacy JBG funds and certain employees of JBG entities that received OP Units in the Formation Transaction (the "OP Units Registration Rights Agreement" and together with the Shares Registration Rights Agreement, the "Registration Rights Agreements"). Certain holders of common shares and OP Units who may benefit from the Registration Rights Agreements are members of our management team and/or Board of Trustees. Our obligations under the Shares Registration Rights Agreement were fully satisfied in January 2018.

Quarterly Financial Data (unaud

Quarterly Financial Data (unaudited)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Data (unaudited)	Quarterly Financial Data (unaudited) 2017 First Quarter Second Quarter Third Quarter (1) Fourth Quarter (2) (In thousands, except per share data) Total revenue $ 116,272 $ 118,020 $ 152,350 $ 156,371 Net income (loss) 6,318 11,341 (77,991 ) (18,752 ) Net income (loss) attributable to common shareholders 6,318 11,341 (69,831 ) (16,418 ) Earnings (loss) per share: Basic 0.06 0.11 (0.61 ) (0.15 ) Diluted 0.06 0.11 (0.61 ) (0.15 ) _______________ (1) During the third quarter of 2017, we recognized transaction and other costs of $104.1 million , a gain on bargain purchase of $27.8 million and share-based compensation expense of $14.4 million in connection with the completion of the Formation Transaction. (2) During the fourth quarter of 2017, we recognized share-based compensation expense of $14.8 million and transaction and other costs of $12.6 million in connection with the completion of the Formation Transaction in the third quarter of 2017. Additionally, we recognized a reduction to the gain on bargain purchase of $3.4 million related to adjustments to the fair value of certain assets acquired and liabilities assumed in the Formation Transaction. See Note 3 for additional information. 2016 First Quarter Second Quarter Third Quarter Fourth Quarter (1) (In thousands, except per share data) Total revenue $ 116,784 $ 116,339 $ 123,357 $ 122,039 Net income 11,547 16,783 21,014 12,630 Net income attributable to common shareholders 11,547 16,783 21,014 12,630 Earnings per share: Basic 0.11 0.17 0.21 0.13 Diluted 0.11 0.17 0.21 0.13 ____________ (1) During the fourth quarter of 2016, we recognized transaction and other costs of $4.9 million in connection with the Formation Transaction completed during the third quarter of 2017.

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2017
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events In January 2018, we entered into an agreement for the sale of Summit I and II, two office assets located in Reston, Virginia, which had an aggregate net carrying value of $87.9 million as of December 31, 2017 for an aggregate gross sales price of $95.0 million . The assets met the held for sale criteria subsequent to December 31, 2017 . In January 2018, we drew an additional $50.0 million under the Tranche A-1 Term Loan, in accordance with the delayed draw provisions of the credit facility. Concurrent with the draw, we entered into an interest rate swap agreement to convert the variable interest rate to a fixed interest rate. In January 2018, we entered into a real estate venture with CIM Group ("CIM") and Pacific Life Insurance Company ("PacLife"), which purchased the 1,152-key Marriott Wardman Park Hotel ("Wardman Park Marriott"), located adjacent to the Woodley Park Metro Station in northwest Washington, DC. We and CIM each contributed $10.1 million for 16.67% interests in the real estate venture and PacLife contributed $40.3 million for the remaining 66.67% interest. Prior to the acquisition, the JBG Legacy Funds owned a 47.64% interest in the Wardman Park Marriott. While the new real estate venture will attempt to improve hotel operations, in the event operations continue to decline, the real estate venture provides a low-cost option to pursue a plan to develop a large and potentially valuable land site in a high value residential market. We do not intend to devote meaningful resources to managing the asset, and intend to only do so if the land development opportunity becomes the primary business plan for the asset. In February 2018, we closed on a joint venture with one of our real estate venture partners, CPPIB, to develop and own 1900 N Street, an under-construction office asset in Washington, DC. CPPIB has committed approximately $101.0 million for a 45% interest, which will reduce our ownership percentage from 100.0% to 55.0% as contributions are funded. In February 2018, we issued an additional 61,309 Formation Units, 357,922 Time-Based LTIP Units and 553,589 Performance-Based LTIP Units to management and employees with an estimated aggregate fair value of $21.1 million .

Schedule II - Valuation and Qua

Schedule II - Valuation and Qualifying Accounts	12 Months Ended
	Dec. 31, 2017
Valuation and Qualifying Accounts [Abstract]
Schedule II - Valuation and Qualifying Accounts	SCHEDULE II JBG SMITH PROPERTIES VALUATION AND QUALIFYING ACCOUNTS Balance at Beginning of Year Additions Charged Against Operations Adjustments to Valuation Accounts Uncollectible Accounts Written‑off Balance at End of Year (In thousands) Year ended December 31, 2017: Allowance for doubtful accounts (1) $ 4,526 $ 3,807 $ — $ (2,048 ) $ 6,285 Year ended December 31, 2016: Allowance for doubtful accounts (1) $ 4,431 $ 751 $ — $ (656 ) $ 4,526 Year ended December 31, 2015: Allowance for doubtful accounts (1) $ 2,514 $ 1,407 $ — $ 510 $ 4,431 _______________ (1) Includes allowance for doubtful accounts related to tenant and other receivables and deferred rent receivable.

Schedule III - Real Estate and

Schedule III - Real Estate and Accumulated Deprecation	12 Months Ended
	Dec. 31, 2017
SEC Schedule III, Real Estate and Accumulated Depreciation Disclosure [Abstract]
SEC Schedule III, Real Estate and Accumulated Depreciation Disclosure	SCHEDULE III JBG SMITH PROPERTIES REAL ESTATE AND ACCUMULATED DEPRECIATION December 31, 2017 Initial Cost to Company Gross Amounts at Which Carried at Close of Period Description Encumbrances (1) Land and Improvements Buildings and Improvements Costs Capitalized Subsequent to Acquisition (2) Land and Improvements Buildings and Total Accumulated Depreciation and Amortization Date of Construction (3) Date Acquired Office Operating Assets Universal Buildings $ 184,357 $ 69,393 $ 143,320 $ 22,547 $ 68,612 $ 166,648 $ 235,260 $ 48,187 1956 2007 2101 L Street 140,493 32,815 51,642 83,766 39,768 128,455 168,223 40,822 1975 2003 Bowen Building — 30,077 98,962 6,238 30,176 105,101 135,277 32,854 1922 2005 1730 M Street — 10,095 17,541 16,111 10,687 33,060 43,747 12,537 1964 2002 1233 20th Street 42,684 30,505 23,130 338 30,505 23,468 53,973 735 1984 2017 Executive Tower — 33,481 67,363 9,306 34,178 75,972 110,150 13,180 2001 2011 1600 K Street — 19,870 10,308 193 19,870 10,501 30,371 402 1950 2017 Courthouse Plaza 1 and 2 2,000 — 105,475 56,173 — 161,648 161,648 67,974 1989 2002 2345 Crystal Drive — 23,126 93,918 35,612 23,546 129,110 152,656 54,253 1988 2002 2121 Crystal Drive 139,134 21,503 87,329 47,790 21,934 134,688 156,622 65,256 1985 2002 1550 Crystal Drive — 22,182 70,525 19,796 21,585 90,918 112,503 37,886 1980 2002 RTC - West 107,720 30,326 134,108 (110 ) 30,397 133,927 164,324 3,330 1988 2017 2231 Crystal Drive — 20,611 83,705 18,856 21,001 102,171 123,172 38,807 1987 2002 2011 Crystal Drive — 18,940 76,921 33,139 18,871 110,129 129,000 45,263 1984 2002 2451 Crystal Drive — 16,755 68,047 27,307 17,090 95,019 112,109 35,934 1990 2002 Commerce Executive — 13,401 58,705 26,122 13,140 85,088 98,228 33,829 1987 2002 1235 S. Clark Street 78,000 15,826 56,090 27,075 16,189 82,802 98,991 30,358 1981 2002 241 18th Street S. — 13,867 54,169 25,164 14,894 78,306 93,200 30,915 1977 2002 251 18th Street S. 35,792 12,305 49,360 50,928 12,809 99,784 112,593 34,678 1975 2002 1215 S. Clark Street 34,299 13,636 48,380 54,196 13,926 102,286 116,212 27,373 1983 2002 201 12th Street S. — 14,766 52,750 22,680 15,036 75,160 90,196 27,838 1987 2002 800 North Glebe Road 107,500 28,168 140,983 2,182 28,168 143,165 171,333 2,737 2012 2017 1225 S. Clark Street — 11,176 43,495 19,649 11,413 62,907 74,320 23,247 1982 2002 2200 Crystal Drive — 13,104 30,050 32,798 13,378 62,574 75,952 18,075 1968 2002 1901 South Bell Street — 11,669 36,918 22,584 11,669 59,502 71,171 24,931 1968 2002 2100 Crystal Drive — 10,287 23,590 31,712 10,520 55,069 65,589 22,490 1968 2002 200 12th Street S. 17,227 8,016 30,552 19,423 8,186 49,805 57,991 18,490 1985 2002 2001 Jefferson Davis Highway — 7,300 16,746 11,297 7,281 28,062 35,343 10,135 1967 2002 Summit I 29,500 7,317 30,626 379 7,317 31,005 38,322 662 1987 2017 Summit II 29,500 5,535 28,463 332 5,535 28,795 34,330 741 1986 2017 1800 South Bell Street — — 28,702 7,220 — 35,922 35,922 14,835 1969 2002 Crystal City Shops at 2100 — 4,059 9,309 5,229 4,049 14,548 18,597 5,611 1968 2002 Wiehle Avenue Office Building — — 96 — — 96 96 48 1984 2017 1831 Wiehle Avenue — — — 24 — 24 24 2 1983 2017 Crystal Drive Retail — — 20,465 6,034 55 26,444 26,499 12,133 2003 2004 7200 Wisconsin Avenue 83,130 34,683 92,059 885 34,683 92,944 127,627 1,763 1986 2017 One Democracy Plaza — — 33,628 6,572 — 40,200 40,200 21,915 1987 2002 4749 Bethesda Avenue Retail — — 11,830 2,664 — 14,494 14,494 — 2016 2017 RTC - West Retail — 2,894 — 7,011 2,894 7,011 9,905 103 2017 2017 Office Construction Assets 1900 N Street — — 8,865 86,336 — 95,201 95,201 — 2017 CEB Tower at Central Place 178,783 — 230,280 117,898 — 348,178 348,178 — 2017 4747 Bethesda Avenue — — 10,040 46,782 — 56,822 56,822 — 2017 Multifamily Operating Assets Fort Totten Square 73,600 24,390 90,404 566 24,390 90,970 115,360 1,785 2015 2017 WestEnd25 99,456 67,049 5,039 109,922 68,201 113,809 182,010 23,983 2009 2007 RiverHouse Apartments 307,710 118,421 125,078 82,825 138,763 187,561 326,324 56,476 1960 2007 The Bartlett 220,000 41,687 — 224,805 41,687 224,805 266,492 10,074 2016 2007 220 20th Street — 8,434 19,340 99,259 8,693 118,340 127,033 27,749 2009 2017 2221 South Clark Street — 7,405 16,981 41,598 7,386 58,598 65,984 4,109 1964 2002 Initial Cost to Company Gross Amounts at Which Carried at Close of Period Description Encumbrances (1) Land and Improvements Buildings and Improvements Costs Capitalized Subsequent to Acquisition (2) Land and Improvements Buildings and Total Accumulated Depreciation and Amortization Date of Construction (3) Date Acquired Falkland Chase - South & West 41,976 18,530 44,232 107 18,530 44,339 62,869 910 1938 2017 Falkland Chase - North 22,566 9,810 22,706 6 9,810 22,712 32,522 477 1938 2017 Multifamily Construction Assets West Half 1,338 — 17,902 69,424 — 87,326 87,326 — 2017 965 Florida Avenue — — — 22,665 — 22,665 22,665 — 2017 1221 Van Street 59,194 — 63,775 46,834 — 110,609 110,609 1 2017 Atlantic Plumbing C — — 13,952 63,269 — 77,221 77,221 — 2017 Other Operating Assets North End Retail — 5,847 9,333 (107 ) 5,847 9,226 15,073 179 2015 2017 Vienna Retail — 1,763 641 41 1,763 682 2,445 213 1981 2005 Crystal City Marriott Hotel — 8,000 47,191 12,595 8,224 59,562 67,786 20,529 1968 2004 Future Development Assets Metropolitan Park 6-8 — 65,259 1,326 26,574 82,898 10,261 93,159 27 2007 Pen Place - Land Parcel — 104,473 55 (32,322 ) 61,970 10,236 72,206 — 2007 1700 M Street Dev — 34,178 46,938 (26,487 ) 34,183 20,446 54,629 — 2002, 2006 Capitol Point - North — 32,730 — 147 32,846 31 32,877 — 2017 Potomac Yard Land Bay G - Parcels A - F — 20,318 — 132 20,318 132 20,450 — 2017 Square 649 — 15,550 6,451 (2,328 ) 12,803 6,870 19,673 367 2005 Other Future Development Assets — 140,919 112,653 (9,091 ) 170,620 73,861 244,481 62 2017 Corporate — — — 21,939 — 21,939 21,939 4,060 2017 2,035,959 1,332,451 2,922,442 1,762,611 1,368,294 4,649,210 6,017,504 1,011,330 Held for sale: Summit II — 1,699 — — 1,699 — 1,699 — 2017 Potomac Yard Land Bay G - Parcel G — 6,594 — — 6,594 — 6,594 — 2017 — 8,293 — — 8,293 — 8,293 — $ 2,035,959 $ 1,340,744 $ 2,922,442 $ 1,762,611 $ 1,376,587 $ 4,649,210 $ 6,025,797 $ 1,011,330 _______________ Note: Depreciation of the buildings and improvements is calculated over lives ranging from the life of the lease to 40 years. As of December 31, 2017 , the cost of real estate, net of accumulated depreciation, for federal income tax purposes was approximately $3.5 billion . (1) Represents the contractual debt obligations. (2) Includes asset impairments recognized and amounts written off in connection with redevelopment activities. (3) Date of original construction, many assets have had substantial renovation or additional construction. See "Costs Capitalized Subsequent to Acquisition" column. The following is a reconciliation of real estate and accumulated depreciation: Year Ended December 31, 2017 2016 2015 (In thousands) Real Estate: Balance at beginning of the year $ 4,155,391 $ 4,038,206 $ 3,809,213 Additions during the year: Land and improvements 428,702 — — Buildings and improvements 1,489,409 217,261 252,113 Held for sale 8,293 — — Less: Assets written‑off (55,998 ) (100,076 ) (23,120 ) Balance at end of the year $ 6,025,797 $ 4,155,391 $ 4,038,206 Accumulated Depreciation: Balance at beginning of period $ 930,769 $ 908,233 $ 797,806 Additions charged to operating expenses 136,559 122,612 133,582 Less: Accumulated depreciation on assets written‑off (55,998 ) (100,076 ) (23,155 ) Balance at end of period $ 1,011,330 $ 930,769 $ 908,233

Summary of Significant Accoun32

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Basis of Presentation	The accompanying consolidated and combined financial statements and notes are prepared in accordance with accounting principles generally accepted in the United States of America ("GAAP"). All intercompany transactions and balances have been eliminated. The accompanying consolidated and combined 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 6 for additional information on our consolidated VIEs. The portions of the equity and net income (loss) of consolidated subsidiaries that are not attributable to JBG SMITH are presented separately as amounts attributable to noncontrolling interests in the consolidated and combined financial statements. References to the financial statements refer to our consolidated and combined financial statements as of December 31, 2017 and 2016 , and for each of the three years in the period ended December 31, 2017 . References to the balance sheets refer to our consolidated and combined balance sheets as of December 31, 2017 and 2016 . References to the statement of operations refer to our consolidated and combined statements of operations for each of the three years in the period ended December 31, 2017 . References to the statement of cash flows refer to our consolidated and combined statements of cash flows for each of the three years in the period ended December 31, 2017 .
Combination	JBG SMITH and the Vornado Included Assets were under common control of Vornado for all periods prior to the Separation. The transfer of the Vornado Included Assets from Vornado to JBG SMITH was completed prior to the Separation, at net book values (historical carrying amounts) carved out from Vornado’s books and records. For purposes of the formation of JBG SMITH, the Vornado Included Assets were designated as the predecessor and the accounting acquirer of the JBG Assets. Consequently, the financial statements of JBG SMITH, as set forth herein, represent a continuation of the financial information of the Vornado Included Assets as the predecessor and accounting acquirer such that the historical financial information included herein as of any date or for any periods on or prior to the completion of the Combination represents the pre-Combination financial information of the Vornado Included Assets. The financial statements reflect the common shares as of the date of the Separation as outstanding for all periods prior to July 17, 2017. The acquisition of the JBG Assets completed subsequently by JBG SMITH was accounted for as a business combination using the acquisition method whereby identifiable assets acquired and liabilities assumed are recorded at the acquisition-date fair values and income and cash flows from the operations were consolidated into the financial statements of JBG SMITH commencing July 18, 2017. Consequently, the financial statements for the periods before and after the Formation Transaction are not directly comparable. The accompanying statements of operations for the year ended December 31, 2017 include our consolidated accounts and the combined accounts of the Vornado Included Assets. Accordingly, the results of operations for the year ended December 31, 2017 reflect the aggregate operations and changes in cash flows and equity on a combined basis for the period prior to July 17, 2017 and on a consolidated basis for the period subsequent to July 17, 2017. The accompanying financial statements for the years ended December 31, 2016 and 2015 include the Vornado Included Assets. Therefore, our results of operations, cash flows and financial condition set forth in this report are not necessarily indicative of our future results of operations, cash flows or financial condition as an independent, publicly traded company. The historical financial results for the Vornado Included Assets reflect charges for certain corporate costs allocated by the former parent which we believe are reasonable. These charges were based on either actual costs incurred or a proportion of costs estimated to be applicable to the Vornado Included Assets based on an analysis of key metrics, including total revenues. Such costs do not necessarily reflect what the actual costs would have been if JBG SMITH had been operating as a separate standalone public company. See Note 18 for additional information. We account for business combinations, including the acquisition of real estate, using the acquisition method pursuant to which we recognize and measure the identifiable assets acquired, liabilities assumed, and any noncontrolling interests in the acquiree at their acquisition date fair values. Accordingly, we estimate the fair values of acquired tangible assets (consisting of real estate, cash and cash equivalents, tenant and other receivables, investments in unconsolidated real estate ventures and other assets, as applicable), identified intangible assets and liabilities (consisting of the value of in-place leases, above- and below-market leases, options to enter into ground leases and management contracts, as applicable), assumed debt and other liabilities, and noncontrolling interests, as applicable, based on our evaluation of information and estimates available at that date. Based on these estimates, we allocate the purchase price to the identified assets acquired and liabilities assumed. Any excess of the purchase price over the estimated fair value of the net assets acquired is recorded as goodwill. Any excess of the fair value of assets acquired over the purchase price is recorded as a gain on bargain purchase. If, up to one year from the acquisition date, information regarding the fair value of the net assets acquired and liabilities assumed is received and estimates are refined, appropriate adjustments are made on a prospective basis to the purchase price allocation, which may include adjustments to identified assets, assumed liabilities, and goodwill or the gain on bargain purchase, as applicable. The results of operations of acquisitions are prospectively included in our financial statements beginning with the date of the acquisition. Transaction costs related to business combinations are expensed as incurred and included in "Transaction and other costs" in our statements of operations. The fair values of buildings are determined using the "as-if vacant" approach whereby we use discounted income or cash flow models with inputs and assumptions that we believe are consistent with current market conditions for similar assets. The most significant assumptions in determining the allocation of the purchase price to buildings are the exit capitalization rate, discount rate, estimated market rents and hypothetical expected lease-up periods. We assess fair value of land based on market comparisons and development projects using an income approach of cost plus a margin. The fair values of identified intangible assets are determined based on the following: • The value allocable to the above- or below-market component of an acquired in-place lease is determined based upon the present value (using a discount rate which reflects the risks associated with the acquired leases) of the difference between (i) the contractual amounts to be received pursuant to the lease over its remaining term and (ii) management’s estimate of the amounts that would be received using market rates over the remaining term of the lease. Amounts allocated to above- market leases are recorded as "Identified intangible assets" in "Other assets, net" in the balance sheets, and amounts allocated to below-market leases are recorded as "Lease intangible liabilities" in "Other liabilities, net" in the balance sheets. These intangibles are amortized to "Property rentals" in our statements of operations over the remaining terms of the respective leases. • Factors considered in determining the value allocable to in-place leases during hypothetical lease-up periods related to space that is leased at the time of acquisition include (i) lost rent and operating cost recoveries during the hypothetical lease-up period and (ii) theoretical leasing commissions required to execute similar leases. These intangible assets are recorded as "Identified intangible assets" in "Other assets, net" in the balance sheets and are amortized to "Depreciation and amortization expenses" in our statements of operations over the remaining term of the existing lease. • The fair value of the in-place property management, leasing, asset management, and development and construction management contracts is based on revenue and expense projections over the estimated life of each contract discounted using a market discount rate. These management contract intangibles are amortized to "Depreciation and amortization expenses" in our statements of operations over the weighted average life of the management contracts. The fair value of investments in unconsolidated real estate ventures and related noncontrolling interests is based on the estimated fair values of the identified assets acquired and liabilities assumed of each venture, including future expected cash flows from promote interests. The fair value of the mortgages payable assumed was determined using current market interest rates for comparable debt financings. The fair values of the interest rate swaps and caps are based on the estimated amounts we would receive or pay to terminate the contract at the acquisition date and are determined using interest rate pricing models and observable inputs. The carrying value of cash, restricted cash, working capital balances, leasehold improvements and equipment, and other assets acquired and liabilities assumed approximates fair value.
Reclassifications	Certain prior period data have been reclassified to conform to the current period presentation as follows: • Reclassification of $4.0 million of investments to "Other assets" on our balance sheet as of December 31, 2016 as a result of the revision in the line item "Investments in and advances to unconsolidated real estate ventures" on our balance sheet to include only real estate investments. • Reclassification of $19.1 million and $18.2 million of expenses for the years ended December 31, 2016 and 2015 to "General and administrative: third-party real estate services" from "Property operating expenses" as it relates to expenses incurred to provide third-party real estate services. Additionally, we reclassified $16.4 million and $15.9 million of income for the years ended December 31, 2016 and 2015 to "Third-party real estate services, including reimbursements" from "Other income" as it relates to revenue earned from providing third-party real estate services.
Use of Estimates	The preparation of the financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at 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 to establish the fair values recorded in connection with the Combination and used in assessing impairment, (ii) the determination of useful lives for tangible and intangible assets and (iii) the allowance for doubtful accounts. Actual results could differ from those estimates.
Real Estate	Real estate is carried at cost, net of accumulated depreciation and amortization. Maintenance and repairs are expensed as incurred and are included in "Property operating expenses" in our statements of operations. As real estate is undergoing redevelopment activities, all property operating expenses directly associated with and attributable to the redevelopment, including interest expense, are capitalized to the extent that we believe such costs are recoverable through the value of the property. The capitalization period ends when redevelopment activities are substantially complete. General and administrative costs are expensed as incurred. Depreciation requires an estimate of the useful life of each property and improvement as well as an allocation of the costs associated with a property to its various components. Depreciation is recognized on a straight‑line basis over estimated useful lives, which range from three to 40 years . Tenant improvements are amortized on a straight‑line basis over the lives of the related leases, which approximate the useful lives of the tenant improvements. Construction in progress, including land, is carried at cost, and no depreciation is recorded. Real estate undergoing significant renovations and improvements is considered to be under development. All direct and indirect costs related to development activities are capitalized into "Construction in progress, including land" on our balance sheets, except for certain demolition costs, which are expensed as incurred. Direct development costs incurred include: pre-development expenditures directly related to a specific project, development and construction costs, interest, insurance and real estate taxes. Indirect development costs include: employee salaries and benefits, travel and other related costs that are directly associated with the development. Our method of calculating capitalized interest expense is based upon applying our weighted average borrowing rate to the actual accumulated expenditures if the property does not have property specific debt. If the property is encumbered by specific debt, we will capitalize both the interest incurred applicable to that debt and additional interest expense using our weighted average borrowing rate for any accumulated expenditures in excess of the principal balance of the debt encumbering the property. The capitalization of such expenses ceases when the real estate is ready for its intended use, but no later than one-year from substantial completion of major construction activity. If we determine that a project is no longer viable, all pre-development project costs are immediately expensed. Our assets and related intangible assets are individually reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of the assets may not be recoverable. An impairment exists when the carrying amount of an asset exceeds the sum of the undiscounted cash flows expected to result from the use and eventual disposition of the asset. Estimates of future cash flows are based on our current plans, intended holding periods and available market information at the time the analyses are prepared. An impairment loss is recognized if the carrying amount of the asset is not recoverable and is measured based on the excess of the property’s carrying amount over its estimated fair value. If our estimates of future cash flows, anticipated holding periods, or fair values change, based on market conditions or otherwise, our evaluation of impairment charges may be different and such differences could be material to our financial statements. Estimates of future cash flows are subjective and are based, in part, on assumptions regarding future occupancy, rental rates and capital requirements that could differ materially from actual results.
Real Estate Held for Sale	Real estate is classified as held for sale when all the necessary criteria are met. The criteria include (i) management, having the authority to approve action, commits to a plan to sell the property in its present condition, (ii) the sale of the property is at a price reasonable in relation to its current fair value and (iii) the sale is probable and expected to be completed within one year. Real estate held for sale is carried at the lower of carrying amounts or estimated fair value less disposal costs. Depreciation and amortization is not recognized on real estate classified as held for sale.
Cash and Cash Equivalents	Cash and cash equivalents consist of highly liquid investments with a purchase date life to maturity of three months or less and are carried at cost, which approximates fair value, due to their short‑term maturities.
Restricted Cash	Restricted cash consists primarily of security deposits held on behalf of our tenants and cash escrowed under loan agreements for debt service, real estate taxes, property insurance and capital improvements.
Allowance for Doubtful Accounts	We periodically evaluate the collectability of amounts due from tenants, including the receivable arising from deferred rent receivable, and maintain an allowance for doubtful accounts for the estimated losses resulting from the inability of tenants to make required payments under lease agreements. We exercise judgment in establishing these allowances and consider payment history and current credit status in developing these estimates.
Investments in and Advances to Real Estate Ventures	We analyze our real estate ventures to determine whether the entities should be consolidated. If it is determined that these investments do not require consolidation because the entities are not VIEs in accordance with the Consolidation Topic of the Financial Accounting Standards Board ("FASB"), Accounting Standards Codification ("ASC"), we are not considered the primary beneficiary of the entities determined to be VIEs, we do not have voting control, and/or the limited partners (or non-managing members) have substantive participatory rights, then the selection of the accounting method used to account for our investments in unconsolidated real estate ventures is generally determined by our voting interests and the degree of influence we have over the entity. Management uses its judgment when determining if we are the primary beneficiary of, or have a controlling financial interest in, an entity in which we have a variable interest. Factors considered in determining whether we have the power to direct the activities that most significantly impact the entity’s economic performance include risk and reward sharing, experience and financial condition of the other partners, voting rights, involvement in day-to-day capital and operating decisions and the extent of our involvement in the entity. We use the equity method of accounting for investments in unconsolidated real estate ventures when we own 20% or more of the voting interests and have significant influence but do not have a controlling financial interest, or if we own less than 20% of the voting interests but have determined that we have significant influence. Under the equity method, we record our investments in and advances to these entities in our balance sheets, and our proportionate share of earnings or losses earned by the real estate venture is recognized in "Income (loss) from unconsolidated real estate ventures, net" in the accompanying statements of operations. We earn revenues from the management services we provide to unconsolidated entities. These fees are 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. We account for this revenue gross of our ownership interest in each respective real estate venture and recognize such revenue in "Third-party real estate services, including reimbursements" in our statements of operations. Our proportionate share of related expenses is recognized in "Income (loss) from unconsolidated real estate ventures, net" in our statements of operations. We may also earn incremental promote distributions if certain financial return benchmarks are achieved upon ultimate disposition of the underlying properties. Management fees are recognized when earned, and promote fees are recognized when certain earnings events have occurred, and the amount is determinable and collectible. Any promote fees are reflected in "Income (loss) from unconsolidated real estate ventures, net" in our statements of operations. With regard to distributions from unconsolidated real estate ventures, we use the information that is available to us to determine the nature of the underlying activity that generated the distributions. Using the nature of distribution approach, cash flows generated from the operations of an unconsolidated real estate venture are classified as a return on investment (cash inflow from operating activities) and cash flows that from property sales, debt refinancing or sales of our investments are classified as a return of investment (cash inflow from investing activities). On a periodic basis, we evaluate our investments in unconsolidated entities for impairment. We assess whether there are any indicators, including underlying property operating performance and general market conditions, that the value of our investments in unconsolidated real estate ventures may be impaired. An investment in a real estate venture is considered impaired if we determine that its fair value is less than the net carrying value of the investment in that real estate venture on an other-than-temporary basis. Cash flow projections for the investments consider property level factors such as expected future operating income, trends and prospects, as well as the effects of demand, competition and other factors. We consider various qualitative factors to determine if a decrease in the value of our investment is other-than-temporary. These factors include age of the venture, our intent and ability to retain our investment in the entity, financial condition and long-term prospects of the entity and relationships with our partners and banks. If we believe that the decline in the fair value of the investment is temporary, no impairment charge is recorded. If our analysis indicates that there is an other-than temporary impairment related to the investment in a particular real estate venture, the carrying value of the venture will be adjusted to an amount that reflects the estimated fair value of the investment.
Intangibles	Intangible assets consist of in-place leases, below-market ground rent obligations, above-market real estate leases and options to enter into ground lease that were recorded in connection with the acquisition of properties. Intangible assets also include management and leasing contracts acquired in the Combination. Intangible liabilities consist of above-market ground rent obligations and below-market real estate leases that are also recorded in connection with the acquisition of properties. Both intangible assets and liabilities are amortized and accreted using the straight-line method over their applicable remaining useful life. When a lease or contract is terminated early, any remaining unamortized or unaccreted balances are charged to earnings. The useful lives of intangible assets are evaluated each reporting period with any changes in estimated useful lives being accounted for over the revised remaining useful life.
Deferred Costs	Deferred financing costs consist of loan issuance costs directly related to financing transactions that are deferred and amortized over the term of the related loan as a component of interest expense. Unamortized deferred financing costs related to our mortgages payable and unsecured term loan are presented as a direct deduction from the carrying amounts of the related debt instruments, while such costs related to our revolving credit facility are included in other assets. Direct salaries, third-party fees and other costs incurred by us to originate a lease are capitalized in "Other assets, net" in the balance sheets and are amortized against the respective leases using the straight-line method over the term of the related leases.
Noncontrolling Interests	We identify our noncontrolling interests separately within the equity section on the balance sheets. Amounts of consolidated net income (loss) attributable to redeemable noncontrolling interests and to the noncontrolling interests in consolidated subsidiaries are presented separately in the statements of operations. Redeemable Noncontrolling Interests - Redeemable noncontrolling interests consists of OP Units issued in conjunction with the Formation Transaction and our venture partner's interest in 965 Florida Avenue. The OP Units are redeemable for our common shares or cash beginning August 1, 2018, subject to certain limitations. Redeemable noncontrolling interests are generally redeemable at the option of the holder and are presented in the mezzanine section between total liabilities and shareholders' equity on the balance sheets. The carrying amount of redeemable noncontrolling interests is adjusted to its redemption value at the end of each reporting period, but no less than its initial carrying value, with such adjustments recognized in "Additional paid-in capital". See Note 11 for additional information. Noncontrolling Interests - Noncontrolling interests represents the portion of equity that we do not own in entities we consolidate, including interests in consolidated real estate ventures.
Derivatives Financial Instruments and Hedge Accounting	Derivative financial instruments are used at times to manage exposure to variable interest rate risk. Derivative financial instruments are recognized as either assets or liabilities and are measured at fair value. The accounting for changes in the fair value of a derivative depends on the intended use of the derivative and the resulting designatio n. Derivative Financial Instruments Designated as Cash Flow Hedges - Certain derivative financial instruments, consisting of interest rate swap and cap agreements, are designated as cash flow hedges, and are carried at their estimated fair value on a recurring basis. We assess the effectiveness of our cash flow hedges both at inception and on an ongoing basis. If the hedges are deemed to be effective, the fair value is recorded in accumulated other comprehensive income and is subsequently reclassified into "Interest expense" in the period that the hedged forecasted transactions affect earnings. Our cash flow hedges become less than perfectly effective if the critical terms of the hedging instrument and the forecasted transactions do not perfectly match such as notional amounts, settlement dates, reset dates, calculation period and interest rates. In addition, we evaluate the default risk of the counterparty by monitoring the credit worthiness of the counterparty. Derivative instruments and hedging activities require management to make judgments on the nature of its derivatives and their effectiveness as hedges. These judgments determine if the changes in fair value of the derivative instruments are reported in the statements of operations or as a component of comprehensive income and as a component of shareholders’ equity on the balance sheets. Derivative Financial Instruments Not Designated as Hedges - Certain derivative financial instruments, consisting of interest rate swap and cap agreements, are considered economic hedges, but not designated as accounting hedges, and are carried at their estimated fair value on a recurring basis. Realized and unrealized gains are recorded in "Interest expense" in the statements of operations in the period in which the change occurs.
Fair Value of Assets and Liabilities	ASC 820, Fair Value Measurement and Disclosures, defines fair value and establishes a framework for measuring fair value. The objective of fair value is to determine the price that would be received upon the sale of an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (the exit price). ASC 820 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 value hierarchy gives the highest priority to Level 1 inputs and the lowest priority to Level 3 inputs. In determining fair value, we utilize valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs to the extent possible as well as consider counterparty credit risk in our assessment of fair value.
Revenue Recognition	Property rentals income includes base rents that 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 leases. We commence rental revenue recognition when the tenant takes possession of the leased space or controls the physical use of the leased space and 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 income 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 also includes the amortization/accretion of acquired above-and below-market leases. Tenant reimbursements provide for the recovery of all or a portion of the operating expenses and real estate taxes of the respective assets. Tenant reimbursements are accrued in the same periods as the related expenses are incurred. 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. Development and construction fees earned from providing services to our unconsolidated real estate ventures are recorded on a percentage of completion basis.
Third-Party Real Estate Services Expenses	Third-party real estate services expenses include the costs associated with the management services provided to our unconsolidated real estate ventures and other third parties. We allocate personnel and other overhead costs using the estimates of the time spent performing services for our third-party real estate services and other allocation methodologies.
Income Taxes	We intend to elect 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. Prior to the Separation, Vornado operated as a REIT and distributed 100% of taxable income to its shareholders, accordingly, no provision for federal income taxes has been made in the accompanying financial statements for the periods prior to the Separation. We intend to adhere to these requirements and maintain our REIT status in future periods. As a REIT, we are allowed to reduce taxable income by all or a portion of our distributions to shareholders. Future distributions will be declared and paid at the discretion of the Board of Trustees and will depend upon cash generated by operating activities, our financial condition, capital requirements, annual dividend requirements under the REIT provisions of the Code, as amended, and such other factors as our Board of Trustees deems relevant. We also participate in the activities conducted by subsidiary entities which have elected to be treated as taxable REIT subsidiaries ("TRS") under the Code. As such, we are subject to federal, state, and local taxes on the income from these activities. Income taxes attributable to our TRSs are accounted for under the asset and liability method. Under the asset and liability method, deferred income taxes arise from temporary differences between the tax basis of assets and liabilities and their reported amounts in the financial statements, which will result in taxable or deductible amounts in the future. ASC 740-10, Income Taxes, provides guidance for how uncertain tax positions should be recognized, measured, presented and disclosed in the financial statements. ASC 740-10 requires the evaluation of tax positions taken in the course of preparing our tax returns to determine whether the tax positions are "more-likely-than-not" of being sustained by the applicable tax authority. Tax benefits of positions not deemed to meet the more-likely-than-not threshold are recorded as a tax expense in the current year.
Earnings (Loss) Per Common Share	Basic earnings (loss) per common share is computed by dividing net income (loss) attributable to common shareholders by the weighted average common shares outstanding during the period. Unvested and vested share-based payment awards that entitle holders to receive non-forfeitable dividends, which include OP Units and long-term incentive partnership units ("LTIP Units"), are considered participating securities. Consequently, we are required to apply the two-class method of computing basic and diluted earnings that would otherwise have been available to common shareholders. Under the two-class method, earnings for the period are allocated between common shareholders and participating securities based on their respective rights to receive dividends. During periods of net loss, losses are allocated only to the extent the participating securities are required to absorb their share of such losses. Diluted earnings per common share reflects the potential dilution of the assumed exchange of various units into common shares unvested share-based payment awards to the extent they are dilutive.
Share-based Compensation	We granted OP Units, formation awards ("Formation Awards"), LTIP Units, LTIP Units with time-based vesting requirements (“Time-Based LTIP Units”) and Performance-Based LTIP Units to our trustees, management and employees in connection with the Separation and Combination. Fair value is determined, depending on the type of award, using the Monte Carlo method or post-vesting restriction periods, which is intended to estimate the fair value of the awards at the grant date using dividend yields and expected volatilities that are primarily based on available implied data and peer group companies' historical data. The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the time of grant. The shortcut method is used for determining the expected life used in the valuation method. Compensation expense is based on the fair value of our common shares at the date of the grant and is recognized ratably over the vesting period using a graded vesting attribution model. We account for forfeitures as they occur. Distributions paid on unvested OP Units, LTIP Units, Time-Based LTIP Units and Performance-Based LTIP Units are charged to "Net income attributable to noncontrolling interests" in the statements of operations.
Recent Accounting Pronouncements	The following table provides a brief description of recent accounting pronouncements (ASU) by the FASB that could have a material effect on our financial statements: Standard Description Date of Adoption Effect on the Financial Statements or Other Significant Matters Standards adopted ASU 2016-15, These standards amend the existing guidance and address specific cash flow issues with the objective of reducing existing diversity in practice. ASU 2016-15 addresses eight specific cash flow issues and ASU 2016-18 specifically addresses presentation of restricted cash and restricted cash equivalents in the statements of cash flows. These standards are effective for interim and annual reporting periods in fiscal years beginning after December 15, 2017, with early adoption permitted. These standards require a retrospective transition method to each period presented. If it is impracticable to apply the amendments retrospectively for some of the issues, entities may apply the amendments prospectively as of the earliest date practicable. December 2017 Other than the revised statement of cash flows presentation of restricted cash, the adoption and implementation of these standards did not have a material impact on our financial statements. The standards were retrospectively applied to prior years. ASU 2017‑05, Other Income—Gains and Losses from the Derecognition of Nonfinancial Assets (Subtopic 610-20): Clarifying the Scope of Asset Derecognition Guidance and Accounting for Partial Sales of Nonfinancial Assets This standard clarifies the scope of recently established guidance on nonfinancial asset derecognition as well as the accounting for partial sales of nonfinancial assets. This update conforms the derecognition guidance on nonfinancial assets with the model for transactions in ASC 606. This standard is effective for interim and annual reporting periods in fiscal years beginning after December 15, 2017, with early adoption permitted. This standard may be adopted either retrospectively or on a modified retrospective basis. December 2017 The adoption and implementation of this standard did not have an impact on our financial statements. In future periods, the adoption of this standard could have a material impact to our results of operations if we sell a significant partial interest in a real estate asset. ASU 2017‑09, Compensation—Stock Compensation (Topic 718): Scope of Modification Accounting This standard clarifies which changes to the terms or conditions of a share-based payment award are subject to the guidance on modification accounting under ASC Topic 718. Entities would apply the modification accounting guidance unless the value, vesting requirements and classification of a share-based payment award are the same immediately before and after a change to the terms or conditions of the award. This standard is effective for annual periods beginning after December 15, 2017, with early adoption permitted. This standard should be applied prospectively. December 2017 The adoption and implementation of this standard did not have an impact on our financial statements. In future periods, if we encounter a change to the terms or conditions of any of our share-based payment awards, we will evaluate the need to apply modification accounting based on the new guidance. The general treatment for modifications of share-based payment awards is to record the incremental value arising from the change as additional compensation expense. ASU 2017-12, Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities The standard provides new guidance for the determination of eligibility for hedge accounting and effectiveness. It also amends the presentation and disclosure requirements. This standard is effective for interim and annual reporting periods in fiscal years beginning after December 15, 2018, with early adoption permitted. This standard requires a modified retrospective transition method which requires the recognition of the cumulative effect of the change on the opening balance of each affected component of equity in the statement of financial position as of the date of adoption. October 2017 The adoption and implementation of this standard did not have a material impact on our financial statements. Standard Description Date of Adoption Effect on the Financial Statements or Other Significant Matters ASU 2017‑01 Business Combinations (Topic 805): Clarifying the Definition of a Business This standard provides guidance for determination of when an asset acquired or group of assets acquired is not a business. The standard requires that when substantially all of the fair value of the gross assets acquired (or disposed of) is concentrated in a single identifiable asset or a group of similar identifiable assets, the set is not a business. This standard reduces the number of transactions that need to be further evaluated. This standard is effective for annual periods beginning after December 15, 2017, with early adoption permitted. This standard should be applied prospectively. September 2017 The adoption and implementation of this standard did not have an impact on our financial statements. In future periods, the adoption of this standard may result in the capitalization of costs associated with asset acquisitions. Standards not yet adopted ASU 2016-02, Leases (Topic 842), as clarified and amended by ASU 2018-01 This standard sets out the principles for the recognition, measurement, presentation and disclosure of leases for both lessees and lessors. ASU 2016-02 requires lessees to apply a dual approach, classifying leases as either finance or operating leases based on the principle of whether or not the lease is effectively a financed purchase. Lessees are required to record a right-of-use asset and a lease liability for all leases with a term of greater than 12 months. Leases with a term of 12 months or less will be accounted for similar to existing guidance for operating leases. Lessees will recognize expense based on the effective interest method for finance leases or on a straight-line basis for operating leases. The FASB has also clarified that an assessment of whether a land easement meets the definition of a lease under the new lease standard will be required. An entity with land easements that are not accounted for as leases under the current lease accounting standards, however, may elect a practical expedient to exclude those land easements from assessment under the new lease accounting standards. The provisions of this standard are effective for fiscal years beginning after December 15, 2018 and should be applied through a modified retrospective transition approach for leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements. Early adoption is permitted. January 2019 We are currently evaluating the overall impact of the adoption of ASU 2016-02 on our financial statements, including the timing of adopting this standard. ASU 2016-02 will more significantly impact the accounting for leases in which we are the lessee. We have ground leases for which we will be required to record a right-of-use asset and lease liability equal to the present value of the remaining minimum lease payments upon adoption of this standard. Under ASU 2016-02, initial direct costs for both lessees and lessors would include only 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 may no longer be able to capitalize internal leasing costs and instead may be required to expense these costs as incurred. Capitalization of internal leasing costs were $2.9 million, $2.5 million and $4.0 million for each of the three years in the period ended December 31, 2017. We do not have any significant land easements. ASU 2014-09, Revenue from Contracts with Customers (Topic 606), as clarified and amended by ASU 2016-08, ASU 2016-10 and ASU 2016-12 This standard establishes a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and supersedes most of the existing revenue recognition guidance. It requires an entity to recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services and also requires certain additional disclosures. This standard is effective beginning after December 15, 2017, including interim reporting periods within that reporting period and may be adopted either retrospectively or on a modified retrospective basis. January 2018 We will utilize the modified retrospective method of adoption. We completed our evaluation of the implementation of this standard, which included gathering and evaluating the inventory of our revenue streams. The standard excludes from its scope the areas of accounting that most significantly affect our revenue recognition, including accounting for leases and financial instruments. Therefore, the adoption of this standard is not expected to have a material impact on our financial statements. We expect this standard will have an impact on the timing of gains on future partial sales of real estate.

Organization and Basis of Pre33

Organization and Basis of Presentation (Tables)	12 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of U.S Governmental Revenue	Only the U.S. federal government accounted for 10% or more of our rental revenue, which consists of property rentals and tenant reimbursements, during each of the three years in the period ended December 31, 2017 as follows: Year Ended December 31, (Dollars in thousands) 2017 2016 2015 Rental revenue from the U.S. federal government $ 92,192 $ 103,864 $ 102,951 Percentage of office segment rental revenue 24.5 % 29.6 % 29.7 % Percentage of total rental revenue 19.4 % 23.6 % 23.9 %

Summary of Significant Accoun34

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Schedule of Recent Accounting Pronouncements	The following table provides a brief description of recent accounting pronouncements (ASU) by the FASB that could have a material effect on our financial statements: Standard Description Date of Adoption Effect on the Financial Statements or Other Significant Matters Standards adopted ASU 2016-15, These standards amend the existing guidance and address specific cash flow issues with the objective of reducing existing diversity in practice. ASU 2016-15 addresses eight specific cash flow issues and ASU 2016-18 specifically addresses presentation of restricted cash and restricted cash equivalents in the statements of cash flows. These standards are effective for interim and annual reporting periods in fiscal years beginning after December 15, 2017, with early adoption permitted. These standards require a retrospective transition method to each period presented. If it is impracticable to apply the amendments retrospectively for some of the issues, entities may apply the amendments prospectively as of the earliest date practicable. December 2017 Other than the revised statement of cash flows presentation of restricted cash, the adoption and implementation of these standards did not have a material impact on our financial statements. The standards were retrospectively applied to prior years. ASU 2017‑05, Other Income—Gains and Losses from the Derecognition of Nonfinancial Assets (Subtopic 610-20): Clarifying the Scope of Asset Derecognition Guidance and Accounting for Partial Sales of Nonfinancial Assets This standard clarifies the scope of recently established guidance on nonfinancial asset derecognition as well as the accounting for partial sales of nonfinancial assets. This update conforms the derecognition guidance on nonfinancial assets with the model for transactions in ASC 606. This standard is effective for interim and annual reporting periods in fiscal years beginning after December 15, 2017, with early adoption permitted. This standard may be adopted either retrospectively or on a modified retrospective basis. December 2017 The adoption and implementation of this standard did not have an impact on our financial statements. In future periods, the adoption of this standard could have a material impact to our results of operations if we sell a significant partial interest in a real estate asset. ASU 2017‑09, Compensation—Stock Compensation (Topic 718): Scope of Modification Accounting This standard clarifies which changes to the terms or conditions of a share-based payment award are subject to the guidance on modification accounting under ASC Topic 718. Entities would apply the modification accounting guidance unless the value, vesting requirements and classification of a share-based payment award are the same immediately before and after a change to the terms or conditions of the award. This standard is effective for annual periods beginning after December 15, 2017, with early adoption permitted. This standard should be applied prospectively. December 2017 The adoption and implementation of this standard did not have an impact on our financial statements. In future periods, if we encounter a change to the terms or conditions of any of our share-based payment awards, we will evaluate the need to apply modification accounting based on the new guidance. The general treatment for modifications of share-based payment awards is to record the incremental value arising from the change as additional compensation expense. ASU 2017-12, Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities The standard provides new guidance for the determination of eligibility for hedge accounting and effectiveness. It also amends the presentation and disclosure requirements. This standard is effective for interim and annual reporting periods in fiscal years beginning after December 15, 2018, with early adoption permitted. This standard requires a modified retrospective transition method which requires the recognition of the cumulative effect of the change on the opening balance of each affected component of equity in the statement of financial position as of the date of adoption. October 2017 The adoption and implementation of this standard did not have a material impact on our financial statements. Standard Description Date of Adoption Effect on the Financial Statements or Other Significant Matters ASU 2017‑01 Business Combinations (Topic 805): Clarifying the Definition of a Business This standard provides guidance for determination of when an asset acquired or group of assets acquired is not a business. The standard requires that when substantially all of the fair value of the gross assets acquired (or disposed of) is concentrated in a single identifiable asset or a group of similar identifiable assets, the set is not a business. This standard reduces the number of transactions that need to be further evaluated. This standard is effective for annual periods beginning after December 15, 2017, with early adoption permitted. This standard should be applied prospectively. September 2017 The adoption and implementation of this standard did not have an impact on our financial statements. In future periods, the adoption of this standard may result in the capitalization of costs associated with asset acquisitions. Standards not yet adopted ASU 2016-02, Leases (Topic 842), as clarified and amended by ASU 2018-01 This standard sets out the principles for the recognition, measurement, presentation and disclosure of leases for both lessees and lessors. ASU 2016-02 requires lessees to apply a dual approach, classifying leases as either finance or operating leases based on the principle of whether or not the lease is effectively a financed purchase. Lessees are required to record a right-of-use asset and a lease liability for all leases with a term of greater than 12 months. Leases with a term of 12 months or less will be accounted for similar to existing guidance for operating leases. Lessees will recognize expense based on the effective interest method for finance leases or on a straight-line basis for operating leases. The FASB has also clarified that an assessment of whether a land easement meets the definition of a lease under the new lease standard will be required. An entity with land easements that are not accounted for as leases under the current lease accounting standards, however, may elect a practical expedient to exclude those land easements from assessment under the new lease accounting standards. The provisions of this standard are effective for fiscal years beginning after December 15, 2018 and should be applied through a modified retrospective transition approach for leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements. Early adoption is permitted. January 2019 We are currently evaluating the overall impact of the adoption of ASU 2016-02 on our financial statements, including the timing of adopting this standard. ASU 2016-02 will more significantly impact the accounting for leases in which we are the lessee. We have ground leases for which we will be required to record a right-of-use asset and lease liability equal to the present value of the remaining minimum lease payments upon adoption of this standard. Under ASU 2016-02, initial direct costs for both lessees and lessors would include only 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 may no longer be able to capitalize internal leasing costs and instead may be required to expense these costs as incurred. Capitalization of internal leasing costs were $2.9 million, $2.5 million and $4.0 million for each of the three years in the period ended December 31, 2017. We do not have any significant land easements. ASU 2014-09, Revenue from Contracts with Customers (Topic 606), as clarified and amended by ASU 2016-08, ASU 2016-10 and ASU 2016-12 This standard establishes a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and supersedes most of the existing revenue recognition guidance. It requires an entity to recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services and also requires certain additional disclosures. This standard is effective beginning after December 15, 2017, including interim reporting periods within that reporting period and may be adopted either retrospectively or on a modified retrospective basis. January 2018 We will utilize the modified retrospective method of adoption. We completed our evaluation of the implementation of this standard, which included gathering and evaluating the inventory of our revenue streams. The standard excludes from its scope the areas of accounting that most significantly affect our revenue recognition, including accounting for leases and financial instruments. Therefore, the adoption of this standard is not expected to have a material impact on our financial statements. We expect this standard will have an impact on the timing of gains on future partial sales of real estate.

The Combination (Tables)

The Combination (Tables)	12 Months Ended
	Dec. 31, 2017
Business Combinations [Abstract]
Schedule of Fair Value of Assets Acquired and Liabilities Assumed	The following allocation of the purchase price is based on the preliminary fair value of the assets acquired and liabilities assumed (in thousands): Fair value of purchase consideration: Common shares and OP Units $ 1,224,885 Cash 20,573 Total consideration paid $ 1,245,458 Fair value of assets acquired and liabilities assumed: Land and improvements $ 338,072 Building and improvements 609,156 Construction in progress, including land 699,800 Leasehold improvements and equipment 7,890 Real estate 1,654,918 Cash 104,529 Restricted cash 13,460 Investments in and advances to unconsolidated real estate ventures 241,611 Identified intangible assets 138,371 Notes receivable (1) 50,934 Identified intangible liabilities (8,687 ) Mortgages payable assumed (2) (768,523 ) Capital lease obligations assumed (3) (33,543 ) Lease assumption liabilities (4) (43,388 ) Deferred tax liability (5) (18,610 ) Other liabilities acquired, net (57,650 ) Noncontrolling interests in consolidated subsidiaries (3,588 ) Net assets acquired 1,269,834 Gain on bargain purchase (6) 24,376 Total consideration paid $ 1,245,458 ____________________ (1) During the year ended December 31, 2017 , we received proceeds of $50.9 million from the repayment of the notes receivable acquired in the Combination. (2) Subject to various interest rate swap and cap agreements assumed in the Combination that are considered economic hedges, but not designated as accounting hedges. (3) In the Combination, two ground leases were assumed that were determined to be capital leases. On July 25, 2017, we purchased a land parcel located in Reston, Virginia associated with one of the ground leases for $19.5 million . (4) Includes a $14.0 million payment to a tenant, which will be paid in 2018, and a $29.4 million lease liability we assumed in relocating a tenant to one of our office buildings. The $29.4 million assumed lease liability is based on the contractual payments we assumed under the tenant’s previous lease, which are partially offset by estimated sub-tenant income we anticipate receiving as we actively pursue a sub-tenant. (5) Related to the management and leasing contracts acquired in the Combination. (6) The Combination resulted in a gain on bargain purchase because the estimated fair value of the identifiable net assets acquired exceeded the purchase consideration by $24.4 million . The purchase consideration was based on the fair value of the common shares and OP Units issued in the Combination. We continue to reassess the recognition and measurement of identifiable assets and liabilities acquired and have preliminarily concluded that all acquired assets and liabilities were recognized and that the valuation procedures and resulting estimates of fair values were appropriate.
Schedule of Fair Value of Common Shares and OP Units Purchase Consideration	The fair value of the common shares and OP Units purchase consideration was determined as follows (i n thousands, except exchange ratio and price per share/unit): Outstanding common shares and common limited partnership units prior to the Combination 100,571 Exchange ratio (1) 2.71 Common shares and OP Units issued in consideration 37,164 Price per share/unit (2) $ 37.10 Fair value of common shares and OP Units issued in consideration $ 1,378,780 Fair value adjustment to OP Units due to transfer restrictions (43,303 ) Portion of consideration attributable to performance of future services (3) (110,591 ) Fair value of common shares and OP Units purchase consideration $ 1,224,886 ____________________ (1) Represents the implied exchange ratio of one common share and OP Unit of JBG SMITH for 2.71 common shares and common limited partnership units prior to the Combination. (2) Represents the volume weighted average share price on July 18, 2017. (3) OP Unit consideration paid to certain of the owners of the JBG Assets which have an estimated fair value of $ 110.6 million is subject to post-combination employment with vesting over periods of either 12 or 60 months and amortization is recognized as compensation expense over the period of employment in "General and administrative expense: Share-based compensation related to Formation Transaction" in the statements of operations.
Schedule of Fair Value of Identified Intangible Assets and Liabilities	The preliminary estimated fair values of tangible and identified intangible assets and liabilities, which have definite lives, are as follows: Total Fair Value Weighted Average Amortization Period Useful Life (1) (In thousands) (In years) Tangible assets: Building and improvements $ 543,584 3 - 40 years Tenant improvements 65,572 Shorter of useful life or remaining life of the respective lease Total building and improvements $ 609,156 Leasehold improvements $ 4,422 Shorter of useful life or remaining life of the respective lease Equipment 3,468 5 years Total leasehold improvements and equipment $ 7,890 Identified intangible assets: In-place leases $ 60,317 6.4 Remaining life of the respective lease Above-market real estate leases 11,732 6.3 Remaining life of the respective lease Below-market ground leases 332 88.5 Remaining life of the respective lease Option to enter into ground lease 17,090 N/A Remaining life of contract Management and leasing contracts (2) 48,900 7.5 Estimated remaining life of contracts, ranging between 3 - 9 years Total identified intangible assets $ 138,371 Identified intangible liabilities: Below-market real estate leases $ 8,687 10.3 Remaining life of the respective lease ____________________ (1) In determining these useful lives, we considered the length of time the asset had been in existence, the maintenance history, as well as anticipated future maintenance, and any contractual stipulations that might limit the useful life. (2) Includes in-place property management, leasing, asset management and development management contracts.
Schedule of Fair Values of Tangible Assets Acquired as Part of Business Combination	The preliminary estimated fair values of tangible and identified intangible assets and liabilities, which have definite lives, are as follows: Total Fair Value Weighted Average Amortization Period Useful Life (1) (In thousands) (In years) Tangible assets: Building and improvements $ 543,584 3 - 40 years Tenant improvements 65,572 Shorter of useful life or remaining life of the respective lease Total building and improvements $ 609,156 Leasehold improvements $ 4,422 Shorter of useful life or remaining life of the respective lease Equipment 3,468 5 years Total leasehold improvements and equipment $ 7,890 Identified intangible assets: In-place leases $ 60,317 6.4 Remaining life of the respective lease Above-market real estate leases 11,732 6.3 Remaining life of the respective lease Below-market ground leases 332 88.5 Remaining life of the respective lease Option to enter into ground lease 17,090 N/A Remaining life of contract Management and leasing contracts (2) 48,900 7.5 Estimated remaining life of contracts, ranging between 3 - 9 years Total identified intangible assets $ 138,371 Identified intangible liabilities: Below-market real estate leases $ 8,687 10.3 Remaining life of the respective lease ____________________ (1) In determining these useful lives, we considered the length of time the asset had been in existence, the maintenance history, as well as anticipated future maintenance, and any contractual stipulations that might limit the useful life. (2) Includes in-place property management, leasing, asset management and development management contracts.
Schedule of Unaudited Pro Forma Information	The unaudited pro forma information for the year ended December 31, 2017 was adjusted to exclude $24.4 million of gain on bargain purchase. The unaudited pro forma information was adjusted to exclude transaction and other costs of $127.7 million and $6.5 million and their respective income tax benefits for the years ended December 31, 2017 and 2016 . Year Ended December 31, 2017 2016 (In thousands, except per share data) Unaudited pro forma information: Total revenue $ 637,672 $ 655,668 Net loss attributable to common shareholders $ (19,343 ) $ (26,961 ) Loss per common share: Basic $ (0.16 ) $ (0.23 ) Diluted $ (0.16 ) $ (0.23 )

Tenants and Other Receivables36

Tenants and Other Receivables, Net (Tables)	12 Months Ended
	Dec. 31, 2017
Receivables [Abstract]
Schedule of Tenants and Other Receivables, Net	The following is a summary of tenant and other receivables, net as of December 31, 2017 and 2016 : December 31, 2017 2016 (In thousands) Tenants $ 30,672 $ 26,278 Third-party real estate services 8,954 2,488 Other 12,992 8,826 Allowance for doubtful accounts (5,884 ) (4,212 ) Total tenant and other receivables, net $ 46,734 $ 33,380

Investments in and Advances t37

Investments in and Advances to Unconsolidated Real Estate Ventures (Tables)	12 Months Ended
	Dec. 31, 2017
Equity Method Investments and Joint Ventures [Abstract]
Composition of Investments	The following is a summary of the composition of our investments in and advances to unconsolidated real estate ventures as of December 31, 2017 and 2016 : Ownership Interest (1) December 31, Real Estate Venture Partners (1) December 31, 2017 2016 (In thousands) Landmark 1.8% - 49.0% $ 95,368 $ — CBREI Venture 5.0% - 64.0% 79,062 — Canadian Pension Plan Investment Board ("CPPIB") 55.0% 36,317 36,312 Brandywine 30.0% 13,741 — Berkshire Group 50.0% 27,761 — JP Morgan 5.0% 9,296 9,335 Other 246 129 Total investments in unconsolidated real estate ventures 261,791 45,776 Advances to unconsolidated real estate ventures 20 — Total investments in and advances to unconsolidated real estate ventures $ 261,811 $ 45,776 _______________ (1) We aggregate our investments in and advances to unconsolidated real estate ventures by real estate venture partner. We have multiple investments with certain venture partners with varying ownership interests. The following is a summary of the debt of our unconsolidated real estate ventures as of December 31, 2017 and 2016 : Weighted Average Effective December 31, December 31, 2017 2016 (In thousands) Variable rate (1) 4.40% $ 534,500 $ 31,000 Fixed rate (2) 3.79% 657,701 273,000 Unconsolidated real estate ventures - mortgages payable 1,192,201 304,000 Unamortized deferred financing costs (2,000 ) (1,034 ) Unconsolidated real estate ventures - mortgages payable, net (3) $ 1,190,201 $ 302,966 ______________ (1) Includes variable rate mortgages payable with interest rate cap agreements. (2) Includes variable rate mortgages payable with interest rates fixed by interest rate swap agreements. (3) See Note 17 for additional information regarding related commitments and contingencies. The following is a summary of the financial information for our unconsolidated real estate ventures as of December 31, 2017 and 2016 and for each of the three years in the period ended December 31, 2017 : December 31, 2017 2016 Combined balance sheet information: (In thousands) Real estate, net $ 2,106,670 $ 463,643 Other assets 264,731 134,596 Total assets $ 2,371,401 $ 598,239 Mortgages payable, net $ 1,190,202 $ 302,966 Other liabilities 76,415 24,896 Total liabilities 1,266,617 327,862 Noncontrolling interests — 343 Total equity 1,104,784 270,034 Total liabilities and equity $ 2,371,401 $ 598,239 Year Ended December 31, 2017 2016 2015 Combined income statement information: (In thousands) Total revenue $ 135,256 $ 68,118 $ 67,275 Operating income 14,741 19,283 21,173 Net income (loss) (7,593 ) 5,234 340

Other Assets, Net (Tables)

Other Assets, Net (Tables)	12 Months Ended
	Dec. 31, 2017
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Summary of Other Assets, net	The following is a summary of other assets, net as of December 31, 2017 and 2016 : December 31, 2017 2016 (In thousands) Deferred leasing costs $ 171,153 $ 157,258 Accumulated amortization (67,180 ) (57,910 ) Deferred leasing costs, net 103,973 99,348 Prepaid expenses 9,038 2,199 Identified intangible assets, net 126,467 3,063 Deferred financing costs on revolving credit facility, net 6,654 — Deposits 6,317 100 Other 11,474 8,245 Total other assets, net $ 263,923 $ 112,955
Summary of Identified Intangible Assets, Net	The following is a summary of the composition of identified intangible assets, net as of December 31, 2017 and 2016 : December 31, 2017 2016 Identified intangible assets: (in thousands) In-place leases $ 72,086 $ 12,777 Above-market real estate leases 12,066 773 Below-market ground leases 2,547 2,215 Option to enter into ground lease 17,090 — Management and leasing contracts 48,900 — Other 206 206 Total identified intangibles assets 152,895 15,971 Accumulated amortization: In-place leases 20,015 10,871 Above-market real estate leases 1,600 612 Below-market ground leases 1,365 1,278 Option to enter into ground lease 78 — Management and leasing contracts 3,209 — Other 161 147 Total accumulated amortization 26,428 12,908 Identified intangible assets, net $ 126,467 $ 3,063
Summary of Amortization Expense	The following is a summary of amortization expense included in the statements of operations related to identified intangible assets for each of the three years in the period ended December 31, 2017 : Year Ended December 31, 2017 2016 2015 (in thousands) In-place lease amortization (1) $ 10,216 $ 485 $ 1,343 Above-market real estate lease amortization (2) 1,428 78 89 Below-market ground lease amortization (3) 87 85 85 Management and leasing contract amortization (1) 3,209 — — Other amortization (1) 14 92 248 Total identified intangible asset amortization $ 14,954 $ 740 $ 1,765 ___________________________________________ (1) Amounts are included in "Depreciation and amortization expenses" in our statements of operations. (2) Amounts are included in "Property rentals revenue" in our statements of operations. (3) Amounts are included in "Property operating expenses" in our statements of operations.
Schedule of Estimated Amortization of Identified Intangible Assets	As of December 31, 2017 , the estimated amortization of identified intangible assets is as follows for the next five years and thereafter: Year ending December 31, Amount (in thousands) 2018 $ 22,338 2019 19,167 2020 16,136 2021 12,607 2022 11,248 Thereafter 44,971 Total $ 126,467

Debt (Tables)

Debt (Tables)	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Summary of Debt	The following is a summary of amounts outstanding under the credit facility as of December 31, 2017 : December 31, 2017 Interest Rate Balance (In thousands) Revolving credit facility (1) 2.66% $ 115,751 Tranche A-1 Term Loan 3.17% $ 50,000 Unamortized deferred financing costs, net (3,463 ) Unsecured term loan, net $ 46,537 __________________________ (1) As of December 31, 2017 , letters of credit with an aggregate face amount of $5.7 million were provided under our revolving credit facility. The following is a summary of mortgages payable as of December 31, 2017 and 2016 : Weighted Average December 31, December 31, 2017 (1) 2016 (In thousands) Variable rate (2) 3.62% $ 498,253 $ 547,291 Fixed rate (3) 4.25% 1,537,706 620,327 Mortgages payable 2,035,959 1,167,618 Unamortized deferred financing costs and premium/discount, net (10,267 ) (2,604 ) Mortgages payable, net $ 2,025,692 $ 1,165,014 Payable to former parent (4) — $ — $ 283,232 __________________________ (1) Includes mortgages payable assumed in the Combination. See Note 3 for additional information. (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) Includes amounts payable to former parent as of December 31, 2016 in connection with the Bowen Building and The Bartlett. See Note 18 for additional information.
Schedule of Maturities of Debt Outstanding	Principal maturities of debt outstanding as of December 31, 2017 , including mortgages payable, the Tranche A-1 Term Loan and borrowings on the revolving credit facility, are as follows: Year ending December 31, Amount (In thousands) 2018 $ 337,513 2019 227,041 2020 225,914 2021 216,545 2022 327,500 Thereafter 867,197 Total $ 2,201,710

Other Liabilities, Net (Tables)

Other Liabilities, Net (Tables)	12 Months Ended
	Dec. 31, 2017
Other Liabilities Disclosure [Abstract]
Composition of Other Liabilities, Net	The following is a summary of other liabilities, net as of December 31, 2017 and 2016 : December 31, 2017 2016 (In thousands) Lease intangible liabilities $ 44,917 $ 36,515 Accumulated amortization (26,950 ) (24,945 ) Lease intangible liabilities, net 17,967 11,570 Prepaid rent 15,751 9,163 Lease assumption liabilities and accrued tenant incentives (1) 50,866 14,907 Capital lease obligation 15,819 — Security deposits 13,618 10,324 Ground lease deferred rent payable 3,730 3,331 Net deferred tax liability 8,202 — Dividends payable (2) 31,097 — Other 4,227 192 Total other liabilities, net $ 161,277 $ 49,487 ___________________________________________ (1) As of December 31, 2017 , includes $43.4 million of lease assumption liabilities assumed in the Combination. See Note 3 for additional information. (2) Dividends declared in December 2017 that were paid in January 2018.
Schedule of Finite-Lived Intangible Liabilities, Future Amortization Expense	As of December 31, 2017 , the estimated amortization of lease intangible liabilities is as follows for the next five years and thereafter: Year ending December 31, Amount (in thousands) 2018 $ 2,695 2019 2,633 2020 2,382 2021 1,905 2022 1,788 Thereafter 6,564 Total $ 17,967

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Schedule of components of income tax expense (benefit)	The following is a summary of our income tax benefit (expense) for each of the three years in the period ended December 31, 2017 : Year Ended December 31, 2017 2016 2015 (in thousands) Current tax benefit (expense) $ (496 ) $ (1,083 ) $ (420 ) Deferred tax benefit (expense) 10,408 — — Income tax benefit (expense) $ 9,912 $ (1,083 ) $ (420 )
Schedule of deferred tax assets and liabilities	December 31, 2017 2016 (in thousands) Deferred tax assets: Accrued bonus $ 1,675 $ — Net operating loss 1,710 — Other 805 — Total deferred tax assets 4,190 — Deferred tax liabilities: Management and leasing contracts (11,840 ) — Other (552 ) — Total deferred tax liabilities (12,392 ) — Net deferred tax liability $ (8,202 ) $ —

Redeemable Noncontrolling Int42

Redeemable Noncontrolling Interests (Tables)	12 Months Ended
	Dec. 31, 2017
Noncontrolling Interest [Abstract]
Redeemable Noncontrolling Interests	Below is a summary of the activity of redeemable noncontrolling interests for the year ended December 31, 2017 : JBG SMITH LP Consolidated Real Estate Venture Total (In thousands) Balance at January 1, 2017 (1) $ — $ — $ — OP Units issued at the Separation 96,632 — 96,632 OP Units issued in connection with the Combination (2) 359,967 — 359,967 Net loss attributable to redeemable noncontrolling interests (7,320 ) (8 ) (7,328 ) Other comprehensive income 225 — 225 Distributions and acquisition of consolidated real estate venture (9,113 ) 5,420 (3,693 ) Share-based compensation expense 32,634 — 32,634 Adjustment to redemption value 130,692 — 130,692 Balance as of December 31, 2017 $ 603,717 $ 5,412 $ 609,129 __________________ (1) We did not have any redeemable noncontrolling interests prior to the Separation on July 17, 2017. (2) Excludes certain OP Units issued in the Combination which have an estimated fair value of $ 110.6 million , that are subject to post-combination employment with vesting over periods of either 12 or 60 months. See Note 12 for additional information.

Share-Based Payments and Empl43

Share-Based Payments and Employee Benefits (Tables)	12 Months Ended
	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedules of Share-based Compensation Activity	The following table presents information regarding the OP Units activity during the year ended December 31, 2017 : Unvested Shares Weighted Average Grant-Date Fair Value Unvested at January 1, 2017 — $ — Granted 3,280,900 33.71 Vested (193,938 ) 37.10 Unvested at December 31, 2017 3,086,962 33.49 The following table presents information regarding the Formation Awards activity during the year ended December 31, 2017 : Unvested Shares Weighted Average Grant-Date Fair Value Unvested at January 1, 2017 — $ — Granted 2,680,552 8.84 Forfeited (6,738 ) 8.84 Unvested at December 31, 2017 2,673,814 8.84 The following table presents information regarding the LTIP and Time-Based LTIP Units activity during the year ended December 31, 2017 : Unvested Shares Weighted Average Grant-Date Fair Value Unvested at January 1, 2017 — $ — Granted 409,611 33.41 Vested (77,129 ) 32.26 Forfeited (275 ) 33.71 Unvested at December 31, 2017 332,207 33.68 The following table presents information regarding the Performance-Based LTIP Units activity during the year ended December 31, 2017 : Unvested Shares Weighted Average Grant-Date Fair Value Unvested at January 1, 2017 — $ — Granted 605,072 15.95 Forfeited (550 ) 15.95 Unvested at December 31, 2017 604,522 15.95
Summary of Share-Based Compensation Expense	Share-based compensation expense for each of the three years in the period ended December 31, 2017 is summarized as follows: Year Ended December 31, 2017 2016 2015 (In thousands) Formation Awards $ 5,169 $ — $ — LTIP Units 2,615 — — OP Units (1) 21,467 — — Share-based compensation related to Formation Transaction (2) 29,251 — — Time-Based LTIP Units that vest over four years 2,211 — — Performance-Based LTIP Units 1,172 — — Other equity awards (3) 1,526 4,502 4,506 Share-based compensation expense - other (4) 4,909 4,502 4,506 Total share-based compensation expense 34,160 4,502 4,506 Less amount capitalized (467 ) — — Net share-based compensation expense $ 33,693 $ 4,502 $ 4,506 ______________________________________________ (1) Represents share-based compensation expense for OP Units subject to post-combination employment. See Note 3 for additional information. (2) Included in "General and administrative expense: Share-based compensation related to Formation Transaction" in the accompanying statements of operations. (3) Represents share-based compensation expense related to equity awards prior to the Formation Transaction. (4) Included in "General and administrative expense" in the accompanying statements of operations.

Earnings (Loss) Per Common Sh44

Earnings (Loss) Per Common Share (Tables)	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Schedule of Earnings (Loss) Per Share, Basic and Diluted	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) available to common shareholders used in calculating basic and diluted earnings (loss) per common share for each of the three years in the period ended December 31, 2017 : Year Ended December 31, 2017 2016 2015 (In thousands, except per share amounts) Net income (loss) $ (79,084 ) $ 61,974 $ 49,628 Net loss attributable to redeemable noncontrolling interests 7,328 — — Net loss attributable to noncontrolling interest 3 — — Net income (loss) attributable to common shareholders (71,753 ) 61,974 49,628 Distributions to participating securities (1,655 ) — — Net income (loss) available to common shareholders $ (73,408 ) $ 61,974 $ 49,628 Weighted average number of common shares outstanding — basic and diluted (1) 105,359 100,571 100,571 Earnings (loss) per common share: Basic $ (0.70 ) $ 0.62 $ 0.49 Diluted (0.70 ) 0.62 0.49 ______________ (1) Reflects the weighted average common shares outstanding as of the date of the Separation in all periods prior to July 17, 2017.
Schedule of Antidilutive Securities Excluded from Computation of Earnings (Loss) Per Share	The number of additional securities excluded from the calculation of diluted earnings (loss) per common share as they were antidilutive, but potentially could be dilutive in the future are included in the following table for each of the three years in the period ended December 31, 2017 : Year Ended December 31, 2017 2016 2015 (In thousands) OP Units 3,087 — — Formation Awards 2,674 — — Time-Based LTIP Units 409 — — Performance-Based LTIP Units 605 — —

Future Minimum Rental Income (T

Future Minimum Rental Income (Tables)	12 Months Ended
	Dec. 31, 2017
Leases [Abstract]
Schedule of Future Minimum Rental Income	As of December 31, 2017 , future base rental revenue under these non-cancelable operating leases excluding extension options is as follows: Year ending December 31, Amount (In thousands) 2018 $ 428,413 2019 341,872 2020 307,181 2021 264,351 2022 226,490 Thereafter 1,167,008

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2017
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 as of December 31, 2017 : Fair Value Measurements Total Level 1 Level 2 Level 3 December 31, 2017 (In thousands) Derivative financial instruments designated as cash flow hedges: Classified as assets in "Other assets, net" $ 1,506 $ — $ 1,506 $ — Classified as liabilities in "Other liabilities, net" 2,640 — 2,640 — Derivative financial instruments not designated as cash flow hedges: Classified as assets in "Other assets, net" $ 635 $ — $ 635 $ — Classified as liabilities in "Other liabilities, net" $ 22 $ — $ 22 $ —
Schedule of Financial Instruments and Liabilities as Reflected on Balance Sheet	As of December 31, 2017 and 2016 , 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: December 31, 2017 December 31, 2016 Carrying Amount (1) Fair Value Carrying Amount (1) Fair Value (In thousands) Financial liabilities: Mortgages payable $ 2,035,959 $ 2,060,899 $ 1,167,618 $ 1,192,267 Revolving credit facility 115,751 115,768 — — Unsecured term loan 50,000 50,029 — — ______________________________________ ( 1) The carrying amount consists of principal only.

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2017
Segment Reporting [Abstract]
Segment information	The following table reflects the reconciliation of net income (loss) attributable common shareholders to consolidated NOI for each of the three years in the period ended December 31, 2017 : Year Ended December 31, 2017 2016 2015 (In thousands) Net income (loss) attributable to common shareholders $ (71,753 ) $ 61,974 $ 49,628 Add: Depreciation and amortization expense 161,659 133,343 144,984 General and administrative expense: Corporate and other 47,131 48,753 44,424 Third-party real estate services 51,919 19,066 18,217 Share-based compensation related to Formation Transaction 29,251 — — Transaction and other costs 127,739 6,476 — Interest expense 58,141 51,781 50,823 Loss on extinguishment of debt 701 — — Income tax expense (benefit) (9,912 ) 1,083 420 Less: Third-party real estate services, including reimbursements 63,236 33,882 29,467 Other income 5,167 5,381 10,854 Loss from unconsolidated real estate ventures, net (4,143 ) (947 ) (4,283 ) Interest and other income (loss), net 1,788 2,992 2,557 Gain on bargain purchase 24,376 — — Net loss attributable to redeemable noncontrolling interests 7,328 — — Net loss attributable to noncontrolling interest 3 — — Consolidated NOI $ 297,121 $ 281,168 $ 269,901 Below is a summary of NOI by segment for each of the three years in the period ended December 31, 2017 : Year Ended December 31, 2017 Office Multifamily Other Elimination of Intersegment Activity Total (In thousands) Rental revenue: Property rentals $ 343,213 $ 85,809 $ 10,508 $ (2,905 ) $ 436,625 Tenant reimbursements 32,315 5,012 658 — 37,985 Total rental revenue 375,528 90,821 11,166 (2,905 ) 474,610 Rental expense: — Property operating 93,834 24,297 8,528 (15,604 ) 111,055 Real estate taxes 50,483 10,940 5,011 — 66,434 Total rental expense 144,317 35,237 13,539 (15,604 ) 177,489 Consolidated NOI $ 231,211 $ 55,584 $ (2,373 ) $ 12,699 $ 297,121 Year Ended December 31, 2016 Office Multifamily Other Elimination of Intersegment Activity Total (In thousands) Rental revenue: Property rentals $ 317,956 $ 63,401 $ 23,234 $ (2,996 ) $ 401,595 Tenant reimbursements 33,361 3,454 846 — 37,661 Total rental revenue 351,317 66,855 24,080 (2,996 ) 439,256 Rental expense: — Property operating 91,128 17,238 7,216 (15,278 ) 100,304 Real estate taxes 46,115 6,993 4,676 — 57,784 Total rental expense 137,243 24,231 11,892 (15,278 ) 158,088 Consolidated NOI $ 214,074 $ 42,624 $ 12,188 $ 12,282 $ 281,168 Year Ended December 31, 2015 Office Multifamily Other Elimination of Intersegment Activity Total (In thousands) Rental revenue: Property rentals $ 311,671 $ 53,071 $ 27,504 $ (2,436 ) $ 389,810 Tenant reimbursements 35,508 2,790 2,178 — 40,476 Total rental revenue 347,179 55,861 29,682 (2,436 ) 430,286 Rental expense: Property operating 92,355 14,606 9,268 (14,718 ) 101,511 Real estate taxes 45,479 6,022 7,373 — 58,874 Total rental expense 137,834 20,628 16,641 (14,718 ) 160,385 Consolidated NOI $ 209,345 $ 35,233 $ 13,041 $ 12,282 $ 269,901 The following is a summary of certain balance sheet data by segment as of December 31, 2017 and 2016 : Office Multifamily Other Elimination of Intersegment Activity Total December 31, 2017 (In thousands) Real estate, at cost $ 3,955,013 $ 1,476,423 $ 594,361 $ — $ 6,025,797 Investments in and advances to unconsolidated real estate ventures 124,659 98,835 38,317 — 261,811 Total assets 3,542,977 1,434,999 1,299,085 (205,254 ) 6,071,807 December 31, 2016 Real estate, at cost $ 2,798,946 $ 959,404 $ 397,041 $ — $ 4,155,391 Investments in and advances to 45,647 — 129 — 45,776 Total assets 2,388,396 873,157 399,087 — 3,660,640

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Schedule of Future Minimum Rental Income	As of December 31, 2017 , future minimum rental payments under non-cancelable operating leases, capital leases and lease assumption liabilities are as follows: Year ending December 31, Amount (In thousands) 2018 $ 13,686 2019 14,073 2020 13,866 2021 13,594 2022 12,845 Thereafter 697,903 Total $ 765,967

Quarterly Financial Data (una49

Quarterly Financial Data (unaudited) (Tables)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Data	2017 First Quarter Second Quarter Third Quarter (1) Fourth Quarter (2) (In thousands, except per share data) Total revenue $ 116,272 $ 118,020 $ 152,350 $ 156,371 Net income (loss) 6,318 11,341 (77,991 ) (18,752 ) Net income (loss) attributable to common shareholders 6,318 11,341 (69,831 ) (16,418 ) Earnings (loss) per share: Basic 0.06 0.11 (0.61 ) (0.15 ) Diluted 0.06 0.11 (0.61 ) (0.15 ) _______________ (1) During the third quarter of 2017, we recognized transaction and other costs of $104.1 million , a gain on bargain purchase of $27.8 million and share-based compensation expense of $14.4 million in connection with the completion of the Formation Transaction. (2) During the fourth quarter of 2017, we recognized share-based compensation expense of $14.8 million and transaction and other costs of $12.6 million in connection with the completion of the Formation Transaction in the third quarter of 2017. Additionally, we recognized a reduction to the gain on bargain purchase of $3.4 million related to adjustments to the fair value of certain assets acquired and liabilities assumed in the Formation Transaction. See Note 3 for additional information. 2016 First Quarter Second Quarter Third Quarter Fourth Quarter (1) (In thousands, except per share data) Total revenue $ 116,784 $ 116,339 $ 123,357 $ 122,039 Net income 11,547 16,783 21,014 12,630 Net income attributable to common shareholders 11,547 16,783 21,014 12,630 Earnings per share: Basic 0.11 0.17 0.21 0.13 Diluted 0.11 0.17 0.21 0.13 ____________ (1) During the fourth quarter of 2016, we recognized transaction and other costs of $4.9 million in connection with the Formation Transaction completed during the third quarter of 2017.

Organization and Basis of Pre50

Organization and Basis of Presentation - Narrative (Details) shares in Thousands, $ in Thousands	Jul. 18, 2017ft²building_unitpropertiesshares	Jul. 17, 2017shares	Jul. 07, 2017	Dec. 31, 2017USD ($)ft²building_unitpropertypropertiesshares	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Real Estate Properties [Line Items]
Common stock issued (in shares) | shares		94,700		117,955
Common limited partnership units (in shares) | shares		5,800
Outstanding common shares and common limited partnership units (in shares) | shares	118,000			117,955
Common limited partnership units outstanding (in shares) | shares	19,800
Number of real estate properties | properties				69
Other assets, net | $				$ 263,923	$ 112,955
Investments in and advances to unconsolidated real estate ventures | $				261,811	45,776
Third-party real estate services | $				51,919	19,066	$ 18,217
Property operating | $				111,055	100,304	101,511
Third-party real estate services, including reimbursements | $				63,236	33,882	29,467
Other income | $				$ 5,167	5,381	10,854
Asset under Construction
Real Estate Properties [Line Items]
Number of real estate properties | properties				10
Future Development
Real Estate Properties [Line Items]
Number of real estate properties | properties				43
Area of real estate property (in square feet)				21,400,000
Office Building
Real Estate Properties [Line Items]
Number of real estate properties | properties				51
Area of real estate property (in square feet)				13,700,000
Office Building | Asset under Construction
Real Estate Properties [Line Items]
Number of real estate properties | properties				4
Area of real estate property (in square feet)				1,300,000
Multifamily
Real Estate Properties [Line Items]
Number of real estate properties | properties				14
Number of building units | building_unit				6,016
Multifamily | Asset under Construction
Real Estate Properties [Line Items]
Number of real estate properties | properties				5
Number of building units | building_unit				1,767
Other Property
Real Estate Properties [Line Items]
Number of real estate properties | properties				4
Area of real estate property (in square feet)				765,000
Other Property | Asset under Construction
Real Estate Properties [Line Items]
Number of real estate properties | property				1
Area of real estate property (in square feet)				41,100
Wholly Owned Properties | Future Development
Real Estate Properties [Line Items]
Area of real estate property (in square feet)				17,900,000
Wholly Owned Properties | Office Building
Real Estate Properties [Line Items]
Area of real estate property (in square feet)				11,800,000
Wholly Owned Properties | Office Building | Asset under Construction
Real Estate Properties [Line Items]
Area of real estate property (in square feet)				1,200,000
Wholly Owned Properties | Multifamily
Real Estate Properties [Line Items]
Number of building units | building_unit				4,232
Wholly Owned Properties | Multifamily | Asset under Construction
Real Estate Properties [Line Items]
Number of building units | building_unit				1,568
Wholly Owned Properties | Other Property
Real Estate Properties [Line Items]
Area of real estate property (in square feet)				348,000
Wholly Owned Properties | Other Property | Asset under Construction
Real Estate Properties [Line Items]
Area of real estate property (in square feet)				4,100
JBG Smith, LP
Real Estate Properties [Line Items]
Ownership interest by parent	85.60%
JBG Companies
Real Estate Properties [Line Items]
Common shares and OP Units issued in consideration (in shares) | shares	37,164
Outstanding common shares and common limited partnership units (in shares) | shares		100,571
Number of real estate properties | properties	30
JBG Companies | Asset under Construction
Real Estate Properties [Line Items]
Number of real estate properties | properties	11
Area of real estate property (in square feet)	2,500,000
JBG Companies | Future Development
Real Estate Properties [Line Items]
Number of real estate properties | properties	26
Area of real estate property (in square feet)	11,700,000
JBG Companies | Office Building
Real Estate Properties [Line Items]
Number of real estate properties | properties	19
Area of real estate property (in square feet)	3,600,000
JBG Companies | Multifamily
Real Estate Properties [Line Items]
Number of real estate properties | properties	9
Number of building units | building_unit	2,883
JBG Companies | Other Property
Real Estate Properties [Line Items]
Number of real estate properties | properties	2
Area of real estate property (in square feet)	490,000
JBG Companies | Wholly Owned Properties | Asset under Construction
Real Estate Properties [Line Items]
Area of real estate property (in square feet)	2,200,000
JBG Companies | Wholly Owned Properties | Future Development
Real Estate Properties [Line Items]
Area of real estate property (in square feet)	8,500,000
JBG Companies | Wholly Owned Properties | Office Building
Real Estate Properties [Line Items]
Area of real estate property (in square feet)	2,300,000
JBG Companies | Wholly Owned Properties | Multifamily
Real Estate Properties [Line Items]
Number of building units | building_unit	1,099
JBG Companies | Wholly Owned Properties | Other Property
Real Estate Properties [Line Items]
Area of real estate property (in square feet)	73,000
JBG Companies | Common Shares
Real Estate Properties [Line Items]
Common shares and OP Units issued in consideration (in shares) | shares	23,200
JBG Companies | Partnership units
Real Estate Properties [Line Items]
Common shares and OP Units issued in consideration (in shares) | shares	13,900
Affiliate | Vornado
Real Estate Properties [Line Items]
Percentage of common shares distributed		100.00%
Spinoff ratio			0.5
Limited Partners spinoff ratio			0.5
Reclassification Adjustment
Real Estate Properties [Line Items]
Other assets, net | $					4,000
Investments in and advances to unconsolidated real estate ventures | $					(4,000)
Third-party real estate services | $					19,100	18,200
Property operating | $					(19,100)	(18,200)
Third-party real estate services, including reimbursements | $					16,400	15,900
Other income | $					$ (16,400)	$ (15,900)
Five Assets | Annualized Rent | Asset Concentration Risk
Real Estate Properties [Line Items]
Concentration risk percentage					25.00%

Organization and Basis of Pre51

Organization and Basis of Presentation - Schedule of Revenue by Major Customer (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disaggregation of Revenue [Line Items]
Revenues	$ 156,371	$ 152,350	$ 118,020	$ 116,272	$ 122,039	$ 123,357	$ 116,339	$ 116,784	$ 543,013	$ 478,519	$ 470,607
U.S. federal government | Office segment revenue
Disaggregation of Revenue [Line Items]
Percentage of revenue									24.50%	29.60%	29.70%
U.S. federal government | Total revenue
Disaggregation of Revenue [Line Items]
Percentage of revenue									19.40%	23.60%	23.90%
U.S. federal government
Disaggregation of Revenue [Line Items]
Revenues									$ 92,192	$ 103,864	$ 102,951

Summary of Significant Accoun52

Summary of Significant Accounting Policies - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Capitalization of internal leasing costs	$ 2.9	$ 2.5	$ 4
Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives (in years)	3 years
Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives (in years)	40 years

The Combination - Narrative (De

The Combination - Narrative (Details) shares in Thousands, $ in Thousands	Jul. 18, 2017USD ($)ft²building_unitpropertiespersonshares	Dec. 31, 2017USD ($)ft²building_unitpropertyproperties	Sep. 30, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2017USD ($)ft²building_unitpropertyproperties	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Business Acquisition [Line Items]
Number of real estate properties | properties		69			69
Transaction and other costs | $					$ 127,739	$ 6,476	$ 0
Gain on bargain purchase | $					24,376	0	$ 0
JBG Companies
Business Acquisition [Line Items]
Common shares and OP Units issued in consideration (in shares) | shares	37,164
Increase to real estate | $		$ 47,500
Decrease to identified intangible assets | $		(8,200)
Increase to investments in and advances to unconsolidated real estate ventures | $		3,200
Increase to lease liabilities | $		43,400
Increase to other liabilities acquired | $		5,600
Decrease in deferred tax liability | $		2,900
Reduction to gain on bargain purchase | $		(3,400)
Number of real estate properties | properties	30
Number of unrelated owners | person	20
Number of owners turned employees | person	19
Number of owners turned board of trustee members | person	3
Transaction and other costs | $		12,600	$ 104,100	$ 4,900	127,700	$ 6,500
Severance and transaction bonus expense | $		$ 40,800			40,800
Investment banking fees | $					33,600
Legal fees | $					13,900
Accounting fees | $					10,800
Revenue of JBG included in statement of operations | $					71,300
Net loss of JBG included in statement of operations | $					$ (23,100)
Gain on bargain purchase | $	$ 24,376		$ 27,800
Office Building
Business Acquisition [Line Items]
Number of real estate properties | properties		51			51
Area of real estate property (in square feet)		13,700,000			13,700,000
Office Building | JBG Companies
Business Acquisition [Line Items]
Number of real estate properties | properties	19
Area of real estate property (in square feet)	3,600,000
Multifamily
Business Acquisition [Line Items]
Number of real estate properties | properties		14			14
Number of building units | building_unit		6,016			6,016
Multifamily | JBG Companies
Business Acquisition [Line Items]
Number of real estate properties | properties	9
Number of building units | building_unit	2,883
Other
Business Acquisition [Line Items]
Number of real estate properties | properties		4			4
Area of real estate property (in square feet)		765,000			765,000
Other | JBG Companies
Business Acquisition [Line Items]
Number of real estate properties | properties	2
Area of real estate property (in square feet)	490,000
Wholly Owned Properties | Office Building
Business Acquisition [Line Items]
Area of real estate property (in square feet)		11,800,000			11,800,000
Wholly Owned Properties | Office Building | JBG Companies
Business Acquisition [Line Items]
Area of real estate property (in square feet)	2,300,000
Wholly Owned Properties | Multifamily
Business Acquisition [Line Items]
Number of building units | building_unit		4,232			4,232
Wholly Owned Properties | Multifamily | JBG Companies
Business Acquisition [Line Items]
Number of building units | building_unit	1,099
Wholly Owned Properties | Other
Business Acquisition [Line Items]
Area of real estate property (in square feet)		348,000			348,000
Wholly Owned Properties | Other | JBG Companies
Business Acquisition [Line Items]
Area of real estate property (in square feet)	73,000
Asset under Construction
Business Acquisition [Line Items]
Number of real estate properties | properties		10			10
Asset under Construction | JBG Companies
Business Acquisition [Line Items]
Number of real estate properties | properties	11
Area of real estate property (in square feet)	2,500,000
Asset under Construction | Office Building
Business Acquisition [Line Items]
Number of real estate properties | properties		4			4
Area of real estate property (in square feet)		1,300,000			1,300,000
Asset under Construction | Multifamily
Business Acquisition [Line Items]
Number of real estate properties | properties		5			5
Number of building units | building_unit		1,767			1,767
Asset under Construction | Other
Business Acquisition [Line Items]
Number of real estate properties | property		1			1
Area of real estate property (in square feet)		41,100			41,100
Asset under Construction | Wholly Owned Properties | JBG Companies
Business Acquisition [Line Items]
Area of real estate property (in square feet)	2,200,000
Asset under Construction | Wholly Owned Properties | Office Building
Business Acquisition [Line Items]
Area of real estate property (in square feet)		1,200,000			1,200,000
Asset under Construction | Wholly Owned Properties | Multifamily
Business Acquisition [Line Items]
Number of building units | building_unit		1,568			1,568
Asset under Construction | Wholly Owned Properties | Other
Business Acquisition [Line Items]
Area of real estate property (in square feet)		4,100			4,100
Near-Term Development | JBG Companies
Business Acquisition [Line Items]
Number of real estate properties | properties	2
Area of real estate property (in square feet)	401,000
Near-Term Development | Wholly Owned Properties | JBG Companies
Business Acquisition [Line Items]
Area of real estate property (in square feet)	242,000
Future Development
Business Acquisition [Line Items]
Number of real estate properties | properties		43			43
Area of real estate property (in square feet)		21,400,000			21,400,000
Future Development | JBG Companies
Business Acquisition [Line Items]
Number of real estate properties | properties	26
Area of real estate property (in square feet)	11,700,000
Future Development | Wholly Owned Properties
Business Acquisition [Line Items]
Area of real estate property (in square feet)		17,900,000			17,900,000
Future Development | Wholly Owned Properties | JBG Companies
Business Acquisition [Line Items]
Area of real estate property (in square feet)	8,500,000

The Combination - Fair Value of

The Combination - Fair Value of Assets Acquired and Liabilities Assumed (Details) $ in Thousands	Jul. 25, 2017USD ($)unit	Jul. 18, 2017USD ($)unit	Sep. 30, 2017USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Fair value of assets acquired and liabilities assumed:
Gain on bargain purchase				$ 24,376	$ 0	$ 0
Repayment of notes receivable				50,934	$ 0	$ 0
JBG Companies
Fair value of purchase consideration:
Common shares and OP Units		$ 1,224,885
Cash		20,573
Total consideration paid		1,245,458
Fair value of assets acquired and liabilities assumed:
Land and improvements		338,072
Building and improvements		609,156
Construction in progress, including land		699,800
Leasehold improvements and equipment		7,890
Real estate		1,654,918
Cash		104,529
Restricted cash		13,460
Investments in and advances to unconsolidated real estate ventures		241,611
Identified intangible assets		138,371
Notes receivable		50,934
Identified intangible liabilities		(8,687)
Mortgages payable assumed		(768,523)
Capital lease obligations assumed		(33,543)
Lease assumption liabilities		(43,388)
Deferred tax liability		(18,610)
Other liabilities acquired, net		(57,650)
Noncontrolling interests in consolidated subsidiaries		(3,588)
Net assets acquired		1,269,834
Gain on bargain purchase		$ 24,376	$ 27,800
Repayment of notes receivable				$ 50,900
Ground leases that qualify as capital leases | unit		2
Lease assumption liabilities, future payments to tenants		$ 14,000
Lease assumption liabilities, relocation of tenants		$ 29,400
Reston, Virginia | JBG Companies
Fair value of assets acquired and liabilities assumed:
Ground leases that qualify as capital leases | unit	1
Land parcel purchase price	$ 19,500

The Combination - Fair Value 55

The Combination - Fair Value of Common Shares and OP Units Purchase Consideration (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	Jul. 18, 2017	Dec. 31, 2017	Jul. 17, 2017
Business Acquisition [Line Items]
Outstanding common shares and common limited partnership units (in shares)	118,000	117,955
JBG Companies
Business Acquisition [Line Items]
Outstanding common shares and common limited partnership units (in shares)			100,571
Exchange ratio	271.00%
Common shares and OP Units issued in consideration (in shares)	37,164
Price per share/unit	$ 37.10
Fair value of common shares and OP Units issued in consideration	$ 1,378,780
Fair value adjustment to OP Units due to transfer restrictions	(43,303)
Portion of consideration attributable to performance of future services	(110,591)
Fair value of common shares and OP Units purchase consideration	1,224,885
OP Units
Business Acquisition [Line Items]
Portion of consideration attributable to performance of future services	$ (110,600)
OP Units | Minimum
Business Acquisition [Line Items]
Vesting period	12 months
OP Units | Maximum
Business Acquisition [Line Items]
Vesting period	60 months

The Combination - Fair Value 56

The Combination - Fair Value of Tangible Assets Acquired and Identified Intangible Assets and Liabilities (Details) - USD ($) $ in Thousands	Jul. 18, 2017	Dec. 31, 2017
Minimum
Identified intangible assets and liabilities:
Useful life (in years)		3 years
Maximum
Identified intangible assets and liabilities:
Useful life (in years)		40 years
JBG Companies
Tangible assets:
Building and improvements	$ 543,584
Tenant improvements	65,572
Total building and improvements	609,156
Leasehold improvements	4,422
Equipment	3,468
Total leasehold improvements and equipment	7,890
Identified intangible assets and liabilities:
Identified intangible assets	138,371
Below-market real estate leases	$ 8,687
Weighted average amortization period (in years)	10 years 3 months 18 days
JBG Companies | Equipment
Identified intangible assets and liabilities:
Useful life (in years)	5 years
JBG Companies | In-place leases
Identified intangible assets and liabilities:
Identified intangible assets	$ 60,317
Weighted average amortization period (in years)	6 years 5 months
JBG Companies | Above-market real estate leases
Identified intangible assets and liabilities:
Identified intangible assets	$ 11,732
Weighted average amortization period (in years)	6 years 3 months
JBG Companies | Below-market ground leases
Identified intangible assets and liabilities:
Identified intangible assets	$ 332
Weighted average amortization period (in years)	88 years 6 months
JBG Companies | Option to enter into ground lease
Identified intangible assets and liabilities:
Identified intangible assets	$ 17,090
JBG Companies | Management and leasing contracts
Identified intangible assets and liabilities:
Identified intangible assets	$ 48,900
Weighted average amortization period (in years)	7 years 6 months
JBG Companies | Minimum | Building and improvements
Identified intangible assets and liabilities:
Useful life (in years)	3 years
JBG Companies | Minimum | Management and leasing contracts
Identified intangible assets and liabilities:
Useful life (in years)	3 years
JBG Companies | Maximum | Building and improvements
Identified intangible assets and liabilities:
Useful life (in years)	40 years
JBG Companies | Maximum | Management and leasing contracts
Identified intangible assets and liabilities:
Useful life (in years)	9 years

The Combination - Pro Forma Inf

The Combination - Pro Forma Information (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Business Combinations [Abstract]
Total revenue	$ 637,672	$ 655,668
Net loss attributable to common shareholders	$ (19,343)	$ (26,961)
Loss per common share: Basic (in dollars per share)	$ (0.16)	$ (0.23)
Loss per common share: Diluted (in dollars per share)	$ (0.16)	$ (0.23)

Tenant and Other Receivables, N

Tenant and Other Receivables, Net (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Receivables [Abstract]
Tenants	$ 30,672,000	$ 26,278,000
Third-party real estate services	8,954,000	2,488,000
Other	12,992,000	8,826,000
Allowance for doubtful accounts	(5,884,000)	(4,212,000)
Total tenant and other receivables, net	46,734,000	33,380,000
Bad debt expense	$ 3,807,000	$ 750,600	$ 1,407,000

Investments in and Advances t59

Investments in and Advances to Unconsolidated Real Estate Ventures - Summary of Composition of Investments (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Schedule of Equity Method Investments [Line Items]
Total investments in unconsolidated real estate ventures	$ 261,791	$ 45,776
Advances to unconsolidated real estate ventures	20	0
Total investments in and advances to unconsolidated real estate ventures	261,811	45,776
Landmark
Schedule of Equity Method Investments [Line Items]
Total investments in unconsolidated real estate ventures	95,368	0
CBREI Venture
Schedule of Equity Method Investments [Line Items]
Total investments in unconsolidated real estate ventures	$ 79,062	0
Canadian Pension Plan Investment Board (CPPIB)
Schedule of Equity Method Investments [Line Items]
Ownership Interest	55.00%
Total investments in unconsolidated real estate ventures	$ 36,317	36,312
Brandywine
Schedule of Equity Method Investments [Line Items]
Ownership Interest	30.00%
Total investments in unconsolidated real estate ventures	$ 13,741	0
Berkshire Group
Schedule of Equity Method Investments [Line Items]
Ownership Interest	50.00%
Total investments in unconsolidated real estate ventures	$ 27,761	0
JP Morgan
Schedule of Equity Method Investments [Line Items]
Ownership Interest	5.00%
Total investments in unconsolidated real estate ventures	$ 9,296	9,335
Other
Schedule of Equity Method Investments [Line Items]
Total investments in unconsolidated real estate ventures	$ 246	$ 129
Minimum | Landmark
Schedule of Equity Method Investments [Line Items]
Ownership Interest	1.80%
Minimum | CBREI Venture
Schedule of Equity Method Investments [Line Items]
Ownership Interest	5.00%
Maximum | Landmark
Schedule of Equity Method Investments [Line Items]
Ownership Interest	49.00%
Maximum | CBREI Venture
Schedule of Equity Method Investments [Line Items]
Ownership Interest	64.00%

Investments in and Advances t60

Investments in and Advances to Unconsolidated Real Estate Ventures - Narrative (Details) - USD ($)	1 Months Ended	12 Months Ended
	Nov. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule of Equity Method Investments [Line Items]
Investment in unconsolidated real estate venture		$ 16,321,000	$ 23,027,000	$ 7,865,000
Capitol Point North
Schedule of Equity Method Investments [Line Items]
Ownership Interest		41.00%
Investment in unconsolidated real estate venture	$ 13,100,000
Mortgages payable
Schedule of Equity Method Investments [Line Items]
Proceeds from debt		$ 79,300,000
Repayment of mortgage loan		250,000,000
Ability to draw additional borrowing capacity		$ 143,700,000
Mortgages payable | Atlantic Plumbing
Schedule of Equity Method Investments [Line Items]
Debt instrument, face amount	$ 110,000,000
Term	5 years
Proceeds from debt	$ 100,000,000
Repayment of mortgage loan	88,400,000
Ability to draw additional borrowing capacity	$ 10,000,000
LIBOR | Mortgages payable | Atlantic Plumbing
Schedule of Equity Method Investments [Line Items]
Mortgage loan interest rate	1.50%

Investments in and Advances t61

Investments in and Advances to Unconsolidated Real Estate Ventures - Summary of Debt (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Equity Method Investments and Joint Ventures [Abstract]
Variable rate, weighted average interest rate	4.40%
Variable rate	$ 534,500	$ 31,000
Fixed rate, weighted average interest rate	3.79%
Fixed rate	$ 657,701	273,000
Unconsolidated real estate ventures - mortgages payable	1,192,201	304,000
Unamortized deferred financing costs	(2,000)	(1,034)
Unconsolidated real estate ventures - mortgages payable, net	$ 1,190,201	$ 302,966

Investments in and Advances t62

Investments in and Advances to Unconsolidated Real Estate Ventures - Condensed Combined Financial Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Combined balance sheet information:
Real estate, net	$ 2,106,670	$ 463,643
Other assets	264,731	134,596
Total assets	2,371,401	598,239
Mortgages payable, net	1,190,202	302,966
Other liabilities	76,415	24,896
Total liabilities	1,266,617	327,862
Noncontrolling interests	0	343
Total equity	1,104,784	270,034
Total liabilities and equity	2,371,401	598,239
Combined income statement information:
Total revenue	135,256	68,118	$ 67,275
Operating income	14,741	19,283	21,173
Net income (loss)	$ (7,593)	$ 5,234	$ 340

Variable Interest Entities (Det

Variable Interest Entities (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity [Line Items]
Assets	$ 163.5	$ 42.4
Variable Interest Entity, Primary Beneficiary
Variable Interest Entity [Line Items]
Assets	111
Liabilities	$ 8.8

Other Assets, Net - Summary of

Other Assets, Net - Summary of Other Assets, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Deferred leasing costs	$ 171,153	$ 157,258
Accumulated amortization	(67,180)	(57,910)
Deferred leasing costs, net	103,973	99,348
Prepaid expenses	9,038	2,199
Identified intangible assets, net	126,467	3,063
Deferred financing costs on revolving credit facility, net	6,654	0
Deposits	6,317	100
Other	11,474	8,245
Total other assets, net	$ 263,923	$ 112,955

Other Assets, Net - Schedule of

Other Assets, Net - Schedule of Identified Intangible Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Total identified intangibles assets	$ 152,895	$ 15,971
Total accumulated amortization	26,428	12,908
Identified intangible assets, net	126,467	3,063
In-place leases
Finite-Lived Intangible Assets [Line Items]
Total identified intangibles assets	72,086	12,777
Total accumulated amortization	20,015	10,871
Above-market real estate leases
Finite-Lived Intangible Assets [Line Items]
Total identified intangibles assets	12,066	773
Total accumulated amortization	1,600	612
Below-market ground leases
Finite-Lived Intangible Assets [Line Items]
Total identified intangibles assets	2,547	2,215
Total accumulated amortization	1,365	1,278
Option to enter into ground lease
Finite-Lived Intangible Assets [Line Items]
Total identified intangibles assets	17,090	0
Total accumulated amortization	78	0
Management and leasing contracts
Finite-Lived Intangible Assets [Line Items]
Total identified intangibles assets	48,900	0
Total accumulated amortization	3,209	0
Other
Finite-Lived Intangible Assets [Line Items]
Total identified intangibles assets	206	206
Total accumulated amortization	$ 161	$ 147

Other Assets, Net - Summary o66

Other Assets, Net - Summary of Amortization Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Total identified intangible asset amortization	$ 14,954	$ 740	$ 1,765
In-place leases
Finite-Lived Intangible Assets [Line Items]
Total identified intangible asset amortization	10,216	485	1,343
Above-market real estate leases
Finite-Lived Intangible Assets [Line Items]
Total identified intangible asset amortization	1,428	78	89
Below-market ground leases
Finite-Lived Intangible Assets [Line Items]
Total identified intangible asset amortization	87	85	85
Management and leasing contracts
Finite-Lived Intangible Assets [Line Items]
Total identified intangible asset amortization	3,209	0	0
Other
Finite-Lived Intangible Assets [Line Items]
Total identified intangible asset amortization	$ 14	$ 92	$ 248

Other Assets, Net - Schedule 67

Other Assets, Net - Schedule of Estimated Amortization of Identified Intangible Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
2,018	$ 22,338
2,019	19,167
2,020	16,136
2,021	12,607
2,022	11,248
Thereafter	44,971
Identified intangible assets, net	$ 126,467	$ 3,063

Debt - Schedule of Mortgages Pa

Debt - Schedule of Mortgages Payable (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Debt, gross	$ 2,201,710
Payable to former parent	$ 0	$ 283,232
Mortgages payable
Debt Instrument [Line Items]
Variable interest rate	3.62%
Fixed interest rate	4.25%
Interest rate on payable to former parent	0.00%
Variable rate amount	$ 498,253	547,291
Fixed rate amount	1,537,706	620,327
Debt, gross	2,035,959	1,167,618
Unamortized deferred financing costs and premium/discount, net	(10,267)	(2,604)
Debt, net	2,025,692	1,165,014
Payable to former parent	$ 0	$ 283,232

Debt - Narrative (Details)

Debt - Narrative (Details)	Jul. 18, 2017USD ($)extension_option	Oct. 31, 2017USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Line of Credit Facility [Line Items]
Loss on extinguishment of debt			$ (701,000)	$ 0	$ 0
Interest costs incurred			65,400,000	54,300,000	55,500,000
Capitalized interest			12,727,000	$ 4,076,000	$ 6,437,000
Mortgages payable
Line of Credit Facility [Line Items]
Net carrying value of real estate collateralizing the mortgages payable			2,900,000,000
Proceeds from new debt			79,300,000
Repayment of mortgages payable			250,000,000
Ability to draw additional borrowing capacity			143,700,000
Loss on extinguishment of debt			(701,000)
Unsecured term loan, net			1,400,000,000
Line of credit
Line of Credit Facility [Line Items]
Credit facility, maximum borrowing capacity	$ 1,400,000,000
Fees and expenses on debt	11,200,000
Line of credit | Revolving credit facility
Line of Credit Facility [Line Items]
Unsecured term loan, net	115,800,000
Credit facility, maximum borrowing capacity	$ 1,000,000,000
Number of debt extension options | extension_option	2
Debt extension option period (in months)	6 months
Line of credit | Tranche A-1 Term Loan
Line of Credit Facility [Line Items]
Unsecured term loan, net	$ 50,000,000	$ 50,000,000
Credit facility, maximum borrowing capacity	200,000,000
Line of credit | Tranche A-2 Term Loan
Line of Credit Facility [Line Items]
Credit facility, maximum borrowing capacity	$ 200,000,000
Minimum | LIBOR | Line of credit | Revolving credit facility
Line of Credit Facility [Line Items]
Basis spread on variable rate	1.10%
Minimum | LIBOR | Line of credit | Tranche A-1 Term Loan
Line of Credit Facility [Line Items]
Basis spread on variable rate	1.20%	1.97%
Minimum | LIBOR | Line of credit | Tranche A-2 Term Loan
Line of Credit Facility [Line Items]
Basis spread on variable rate	1.55%
Maximum | LIBOR | Line of credit | Revolving credit facility
Line of Credit Facility [Line Items]
Basis spread on variable rate	1.50%
Maximum | LIBOR | Line of credit | Tranche A-1 Term Loan
Line of Credit Facility [Line Items]
Basis spread on variable rate	1.70%
Maximum | LIBOR | Line of credit | Tranche A-2 Term Loan
Line of Credit Facility [Line Items]
Basis spread on variable rate	2.35%
JBG Companies
Line of Credit Facility [Line Items]
Mortgages payable assumed	$ (768,523,000)
JBG Companies | Mortgages payable
Line of Credit Facility [Line Items]
Mortgages payable assumed	$ (768,500,000)
Repayment of mortgages payable			$ 64,800,000

Debt - Summary of Amounts Outst

Debt - Summary of Amounts Outstanding under the Credit Facility (Details) $ in Thousands	Dec. 31, 2017USD ($)
Line of Credit Facility [Line Items]
Long-term debt, gross	$ 2,201,710
Line of credit | Revolving credit facility
Line of Credit Facility [Line Items]
Interest Rate	2.66%
Debt, net	$ 115,751
Letters of credit	$ 5,700
Line of credit | Tranche A-1 Term Loan
Line of Credit Facility [Line Items]
Interest Rate	3.17%
Long-term debt, gross	$ 50,000
Unamortized deferred financing costs, net	(3,463)
Debt, net	$ 46,537

Debt - Schedule of Principal Ma

Debt - Schedule of Principal Maturities Outstanding (Details) $ in Thousands	Dec. 31, 2017USD ($)
Debt Disclosure [Abstract]
2,018	$ 337,513
2,019	227,041
2,020	225,914
2,021	216,545
2,022	327,500
Thereafter	867,197
Debt, gross	$ 2,201,710

Other Liabilities, Net - Summar

Other Liabilities, Net - Summary of Other Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Jul. 18, 2017	Dec. 31, 2016
Schedule of Other Liabilities [Line Items]
Lease intangible liabilities	$ 44,917		$ 36,515
Accumulated amortization	(26,950)		(24,945)
Lease intangible liabilities, net	17,967		11,570
Prepaid rent	15,751		9,163
Lease assumption liabilities and accrued tenant incentives	50,866		14,907
Capital lease obligation	15,819		0
Security deposits	13,618		10,324
Ground lease deferred rent payable	3,730		3,331
Net deferred tax liability	8,202		0
Dividends payable	31,097		0
Other	4,227		192
Total other liabilities, net	$ 161,277		$ 49,487
JBG Companies
Schedule of Other Liabilities [Line Items]
Lease assumption liabilities		$ (43,388)

Other Liabilities, Net - Summ73

Other Liabilities, Net - Summary of Amortization Expense (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Management and leasing contracts
Schedule of Other Liabilities [Line Items]
Lease intangible liabilities amortization	$ 2.3	$ 1.4	$ 2.9

Other Liabilities, Net - Schedu

Other Liabilities, Net - Schedule of Finite-Lived Intangible Liabilities, Future Amortization Expense (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Other Liabilities Disclosure [Abstract]
2,018	$ 2,695
2,019	2,633
2,020	2,382
2,021	1,905
2,022	1,788
Thereafter	6,564
Lease intangible liabilities, net	$ 17,967	$ 11,570

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Taxes [Line Items]
Federal income tax expense	$ (9,912,000)	$ 1,083,000	$ 420,000
Net tax benefit due to Tax Act	3,900,000
Net operating loss carryforward	6,200,000
Cost of real estate for federal income tax purposes	3,500,000,000
Net deferred tax liability	$ 8,202,000	$ 0
Dividends declared (in dollars per share)	$ 0.45	$ 0	$ 0
Dividends declared, taxable in current year (in dollars per share)	0.31
Dividends declared, taxable in next fiscal year (in dollars per share)	$ 0.14
REIT Subsidiaries
Income Taxes [Line Items]
Federal income tax expense	$ 0	$ 0	$ 0

Income Taxes - Schedule of Comp

Income Taxes - Schedule of Components of Income Tax Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Current tax benefit (expense)	$ (496)	$ (1,083)	$ (420)
Deferred tax benefit (expense)	10,408	0	0
Income tax benefit (expense)	$ (9,912)	$ 1,083	$ 420

Income Taxes - Schedule of Defe

Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred tax assets:
Accrued bonus	$ 1,675	$ 0
Net operating loss	1,710	0
Other	805	0
Total deferred tax assets	4,190	0
Deferred tax liabilities:
Management and leasing contracts	(11,840)	0
Other	(552)	0
Total deferred tax liabilities	(12,392)	0
Net deferred tax liability	$ (8,202)	$ 0

Redeemable Noncontrolling Int78

Redeemable Noncontrolling Interests - Narrative (Details) - USD ($) shares in Millions, $ in Millions	Jul. 18, 2017	Nov. 30, 2017	Dec. 31, 2017	Oct. 31, 2017
JBG Smith, LP
Noncontrolling Interest [Line Items]
Ownership interest by parent	85.60%
Consolidated Real Estate Venture
Noncontrolling Interest [Line Items]
Ownership interest by parent			67.60%
Payments to acquire interest in joint venture		$ 1.5
Ownership interest by noncontrolling owners				37.90%
Ownership interest by parent, threshold for capital contributions to cease		97.00%
OP Units
Noncontrolling Interest [Line Items]
Common shares and OP Units issued in consideration	19.8
OP Units | JBG Smith, LP
Noncontrolling Interest [Line Items]
Ownership interest by parent	14.40%
Minimum
Noncontrolling Interest [Line Items]
Redemption period			2 years
Maximum
Noncontrolling Interest [Line Items]
Redemption period			7 years

Redeemable Noncontrolling Int79

Redeemable Noncontrolling Interests - Summary of the Activity of Redeemable Noncontrolling Interests (Details) - USD ($) $ in Thousands		Jul. 18, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Temporary Equity
Beginning Balance			$ 0
OP Units issued at the Separation	[1]		96,632	$ 0	$ 0
OP Units issued in connection with the Combination			359,967
Net loss attributable to redeemable noncontrolling interests			(7,328)
Other comprehensive income			225
Distributions and acquisition of consolidated real estate venture			(3,693)
Share-based compensation expense			32,634
Adjustment to record redeemable noncontrolling interest at redemption value	[1]		130,692	0	$ 0
Ending Balance			609,129	0
OP Units
Temporary Equity
Portion of consideration attributable to performance of future services		$ 110,600
OP Units | Minimum
Temporary Equity
Vesting period		12 months
OP Units | Maximum
Temporary Equity
Vesting period		60 months
JBG Smith, LP
Temporary Equity
Beginning Balance			0
OP Units issued at the Separation			96,632
OP Units issued in connection with the Combination			359,967
Net loss attributable to redeemable noncontrolling interests			(7,320)
Other comprehensive income			225
Distributions and acquisition of consolidated real estate venture			(9,113)
Share-based compensation expense			32,634
Adjustment to record redeemable noncontrolling interest at redemption value			130,692
Ending Balance			603,717	0
Consolidated Real Estate Venture
Temporary Equity
Beginning Balance			0
OP Units issued at the Separation			0
OP Units issued in connection with the Combination			0
Net loss attributable to redeemable noncontrolling interests			(8)
Other comprehensive income			0
Distributions and acquisition of consolidated real estate venture			5,420
Share-based compensation expense			0
Adjustment to record redeemable noncontrolling interest at redemption value			0
Ending Balance			$ 5,412	$ 0
[1]	See Note 3 for information regarding assets, liabilities and noncontrolling interests acquired in the Formation Transaction.

Share-Based Payments and Empl80

Share-Based Payments and Employee Benefits - OP Units (Details) - OP Units - USD ($) $ / shares in Units, $ in Millions	Jul. 18, 2017	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Equity grants (in shares)	3,300,000	3,280,900
Portion of consideration attributable to performance of future services	$ 110.6
Shares
Beginning balance (in shares)		0
Granted (in shares)	3,300,000	3,280,900
Vested in period (in shares)		(193,938)
Ending balance (in shares)		3,086,962
Weighted Average Grant-Date Fair Value
Beginning balance (in dollars per share)		$ 0
Granted (in dollars per share)		33.71
Vested (in dollars per share)		37.10
Ending balance (in dollars per share)		$ 33.49
Minimum
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Vesting period	12 months
Expected volatility rate	18.00%
Risk-free interest rate	1.30%
Expected life (in years)	1 year
Maximum
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Vesting period	60 months
Expected volatility rate	27.00%
Risk-free interest rate	1.50%
Expected life (in years)	3 years

Share-Based Payments and Empl81

Share-Based Payments and Employee Benefits - JBG Smith 2017 Omnibus Share Plan (Details) - Omnibus Share Plan, 2017 - shares shares in Millions	Dec. 31, 2017	Jul. 17, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized		10.3
Number of shares available for issuance	6.6

Share-Based Payments and Empl82

Share-Based Payments and Employee Benefits - Formation Awards (Details) - USD ($) $ / shares in Units, $ in Millions	Jul. 18, 2017	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Compensation expense recognition period (in years)		3 years 3 months 18 days
Formation Awards
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Equity grants (in shares)	2,700,000	2,680,552
Aggregate notional value of shares granted	$ 100
Weighted average grant-date fair value (in dollars per share)	$ 37.10	$ 0
Vesting period	10 years
Fair value of awards on grant date	$ 23.7
Fair value of awards on grant date (in dollars per unit)	$ 8.84
Expected volatility rate	26.00%
Dividend yield rate	2.30%
Risk-free interest rate	2.30%
Expected life (in years)	7 years
Compensation expense recognition period (in years)		5 years
Shares
Beginning balance (in shares)		0
Granted (in shares)	2,700,000	2,680,552
Forfeited (in shares)		(6,738)
Ending balance (in shares)		2,673,814
Weighted Average Grant-Date Fair Value
Beginning balance (in dollars per share)		$ 0
Granted (in dollars per share)		8.84
Forfeited (in dollars per share)		8.84
Ending balance (in dollars per share)	$ 37.10	$ 8.84
Vesting Period One | Formation Awards
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Percentage of vesting rights for each tranche	25.00%
Vesting Period Two | Formation Awards
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Percentage of vesting rights for each tranche	25.00%
Vesting Period Three | Formation Awards
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Percentage of vesting rights for each tranche	50.00%

Share-Based Payments and Empl83

Share-Based Payments and Employee Benefits - LTIP and Time-Based LTIP Units (Details)	Aug. 01, 2017installment$ / sharesshares	Jul. 18, 2017USD ($)personshares	Dec. 31, 2017USD ($)$ / sharesshares	Dec. 31, 2017$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Compensation expense recognition period (in years)				3 years 3 months 18 days
LTIP and 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)				409,611
Weighted average grant-date fair value (in dollars per share) | $ / shares			$ 33.68	$ 0
Shares
Beginning balance (in shares)				0
Granted (in shares)				409,611
Vested in period (in shares)				(77,129)
Forfeited (in shares)				(275)
Ending balance (in shares)			332,207	332,207
Weighted Average Grant-Date Fair Value
Beginning balance (in dollars per share) | $ / shares				$ 0
Granted (in dollars per share) | $ / shares				33.41
Vested (in dollars per share) | $ / shares				32.26
Forfeited (in dollars per share) | $ / shares				33.71
Ending balance (in dollars per share) | $ / shares			$ 33.68	$ 33.68
LTIP and Time-Based LTIP Units | Minimum
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Expected volatility rate				17.00%
Risk-free interest rate				1.30%
Expected life (in years)				2 years
LTIP and Time-Based LTIP Units | Maximum
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Expected volatility rate				19.00%
Risk-free interest rate				1.50%
Expected life (in years)				3 years
LTIP Units
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Equity grants (in shares)		47,166
Fair value of awards on grant date | $			$ 3,500,000
Shares
Granted (in shares)		47,166
LTIP Units | Vesting Period One
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Percentage of vesting rights for each tranche		50.00%
LTIP Units | Vesting Period Two
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Percentage of vesting rights for each tranche		50.00%
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)	302,518
Vesting period				4 years
Number of installments | installment	4
Weighted average grant-date fair value (in dollars per share) | $ / shares	$ 33.71
Compensation expense recognition period (in years)				4 years
Shares
Granted (in shares)	302,518
Weighted Average Grant-Date Fair Value
Ending balance (in dollars per share) | $ / shares	$ 33.71
Trustee | LTIP Units
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Number of non-employee trustees | person		7
Fair value of awards on grant date | $		$ 250,000
Trustee | LTIP Units | Minimum
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Vesting period		31 months
Trustee | LTIP Units | Maximum
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Vesting period		60 months
Key Employee | LTIP Units
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Equity grants (in shares)		59,927
Shares
Granted (in shares)		59,927

Share-Based Payments and Empl84

Share-Based Payments and Employee Benefits - Performance-Based LTIP Units (Details) - USD ($) $ / shares in Units, $ in Millions	Aug. 01, 2017	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Compensation expense recognition period (in years)		3 years 3 months 18 days
Performance-Based LTIP Units
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Equity grants (in shares)	605,072	605,072
Vesting period	3 years
Fair value of awards on grant date	$ 9.7
Fair value of awards on grant date (in dollars per unit)	$ 15.95
Expected volatility rate	18.00%
Dividend yield rate	2.30%
Risk-free interest rate	1.50%
Compensation expense recognition period (in years)	4 years
Shares
Beginning balance (in shares)		0
Granted (in shares)	605,072	605,072
Forfeited (in shares)		(550)
Ending balance (in shares)		604,522
Weighted Average Grant-Date Fair Value
Beginning balance (in dollars per share)		$ 0
Granted (in dollars per share)		15.95
Forfeited (in dollars per share)		15.95
Ending balance (in dollars per share)		$ 15.95
Performance-Based LTIP Units | Vesting Period One
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Percentage of vesting rights for each tranche	50.00%
Performance-Based LTIP Units | Vesting Period Two
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Percentage of vesting rights for each tranche	50.00%

Share-Based Payments and Empl85

Share-Based Payments and Employee Benefits - Summary of Share-Based Compensation Expense (Details) - USD ($) $ in Thousands	Aug. 01, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation related to Formation Transaction		$ 29,251	$ 0	$ 0
Less amount capitalized		(467)	0	0
Net share-based compensation expense		33,693	4,502	4,506
Total unrecognized compensation expense		$ 124,900
Compensation expense recognition period (in years)		3 years 3 months 18 days
Formation Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation related to Formation Transaction		$ 5,169	0	0
Compensation expense recognition period (in years)		5 years
LTIP Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation related to Formation Transaction		$ 2,615	0	0
OP Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation related to Formation Transaction		21,467	0	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		29,251	0	0
Time-Based LTIP Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation related to Formation Transaction		$ 2,211	0	0
Compensation expense recognition period (in years)		4 years
Performance-Based LTIP Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation related to Formation Transaction		$ 1,172	0	0
Compensation expense recognition period (in years)	4 years
Other Equity Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation related to Formation Transaction		1,526	4,502	4,506
Share-based compensation expense - other
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation related to Formation Transaction		4,909	4,502	4,506
Total share-based compensation expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation related to Formation Transaction		$ 34,160	$ 4,502	$ 4,506

Share-Based Payments and Empl86

Share-Based Payments and Employee Benefits - Employee Benefits (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Matching contributions, vesting period	5 years
Contributions to the 401(k) Plan	$ 3.6	$ 2.4	$ 2.3

Earnings (Loss) Per Common Sh87

Earnings (Loss) Per Common Share - Schedule of Earnings (Loss) Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Earnings Per Share [Abstract]
Net income (loss)	$ (18,752)	$ (77,991)	$ 11,341	$ 6,318	$ 12,630	$ 21,014	$ 16,783	$ 11,547	$ (79,084)	$ 61,974	$ 49,628
Net loss attributable to redeemable noncontrolling interests									(7,328)	0	0
Net loss attributable to noncontrolling interest									(3)	0	0
NET INCOME (LOSS) ATTRIBUTABLE TO COMMON SHAREHOLDERS									(71,753)	61,974	49,628
Distributions to participating securities									(1,655)	0	0
Net income (loss) available to common shareholders	$ (16,418)	$ (69,831)	$ 11,341	$ 6,318	$ 12,630	$ 21,014	$ 16,783	$ 11,547	$ (73,408)	$ 61,974	$ 49,628
Weighted average number of shares outstanding - basic and diluted ( in shares)									105,359	100,571	100,571
Earnings (loss) per common share:
Basic (in dollars per share)	$ (0.15)	$ (0.61)	$ 0.11	$ 0.06	$ 0.13	$ 0.21	$ 0.17	$ 0.11	$ (0.70)	$ 0.62	$ 0.49
Diluted (in dollars per share)	$ (0.15)	$ (0.61)	$ 0.11	$ 0.06	$ 0.13	$ 0.21	$ 0.17	$ 0.11	$ (0.70)	$ 0.62	$ 0.49

Earnings (Loss) Per Common Sh88

Earnings (Loss) Per Common Share - Narrative (Details) shares in Millions	12 Months Ended
	Dec. 31, 2017shares
Conversion of OP Units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	16.7

Earnings (Loss) Per Common Sh89

Earnings (Loss) Per Common Share - Antidilutive Securities Excluded (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
OP Units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	3,087	0	0
Formation Awards
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	2,674	0	0
Time-Based LTIP Units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	409	0	0
Performance-Based LTIP Units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	605	0	0

Future Minimum Rental Income (D

Future Minimum Rental Income (Details) $ in Thousands	Dec. 31, 2017USD ($)
Leases [Abstract]
2,018	$ 428,413
2,019	341,872
2,020	307,181
2,021	264,351
2,022	226,490
Thereafter	$ 1,167,008

Fair Value Measurements - Narra

Fair Value Measurements - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Fair Value Disclosures [Abstract]
Net unrealized gain on derivative designated as cash flow hedge	$ 1,800
Loss expected to be reclassified into interest expense within the next 12 months	3,600
Net unrealized gain on derivative not designated as cash flow hedge	$ 1,348	$ 0	$ 0

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 $ in Thousands	Dec. 31, 2017USD ($)
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	$ 1,506
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
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	1,506
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
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	635
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
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	635
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
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	2,640
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
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	2,640
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
Other Liabilities, Net | Not Designated as Hedging Instrument
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Classified as liabilities in Other liabilities, net	22
Other Liabilities, Net | Not 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
Other Liabilities, Net | Not 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	22
Other Liabilities, Net | Not 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

Fair Value Measurements - Finan

Fair Value Measurements - Financial Assets and Liabilities Not Measured at Fair Value (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Mortgages payable | Carrying Amount
Financial liabilities:
Financial liabilities	$ 2,035,959	$ 1,167,618
Mortgages payable | Fair Value
Financial liabilities:
Financial liabilities	2,060,899	1,192,267
Revolving credit facility | Carrying Amount
Financial liabilities:
Financial liabilities	115,751	0
Revolving credit facility | Fair Value
Financial liabilities:
Financial liabilities	115,768	0
Unsecured term loan | Carrying Amount
Financial liabilities:
Financial liabilities	50,000	0
Unsecured term loan | Fair Value
Financial liabilities:
Financial liabilities	$ 50,029	$ 0

Segment Information - Narrative

Segment Information - Narrative (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)segment	Dec. 31, 2016USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment	3
Number of operating segments | segment	3
Other assets, net | $	$ 263,923	$ 112,955
Third-Party Real Estate Services Segment
Segment Reporting Information [Line Items]
Other assets, net | $	$ 45,700

Segment Information - Schedule

Segment Information - Schedule of Reconciliation of Net Income Attributable to Parent (Details) - USD ($) $ in Thousands	Jul. 18, 2017	Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Business Acquisition [Line Items]
Net income (loss) attributable to common shareholders					$ (71,753)	$ 61,974	$ 49,628
Depreciation and amortization					161,659	133,343	144,984
Corporate and other					47,131	48,753	44,424
Third-party real estate services					51,919	19,066	18,217
Share-based compensation related to Formation Transaction					29,251	0	0
Transaction and other costs					127,739	6,476	0
Interest expense					58,141	51,781	50,823
Loss on extinguishment of debt					701	0	0
Income tax expense (benefit)					(9,912)	1,083	420
Third-party real estate services, including reimbursements					63,236	33,882	29,467
Other income					5,167	5,381	10,854
Loss from unconsolidated real estate ventures, net					(4,143)	(947)	(4,283)
Interest and other income, net					1,788	2,992	2,557
Gain on bargain purchase					24,376	0	0
Net loss attributable to redeemable noncontrolling interests					7,328	0	0
Net loss attributable to noncontrolling interest					3	0	0
Consolidated NOI					297,121	281,168	$ 269,901
JBG Companies
Business Acquisition [Line Items]
Share-based compensation related to Formation Transaction		$ 14,800	$ 14,400
Transaction and other costs		$ 12,600	104,100	$ 4,900	$ 127,700	$ 6,500
Gain on bargain purchase	$ 24,376		$ 27,800

Segment Information - Summary o

Segment Information - Summary of NOI by Segment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Property rentals	$ 436,625	$ 401,595	$ 389,810
Tenant reimbursements	37,985	37,661	40,476
Total rental revenue	474,610	439,256	430,286
Property operating	111,055	100,304	101,511
Real estate taxes	66,434	57,784	58,874
Total rental expense	177,489	158,088	160,385
Consolidated NOI	297,121	281,168	269,901
Operating Segments | Office
Segment Reporting Information [Line Items]
Property rentals	343,213	317,956	311,671
Tenant reimbursements	32,315	33,361	35,508
Total rental revenue	375,528	351,317	347,179
Property operating	93,834	91,128	92,355
Real estate taxes	50,483	46,115	45,479
Total rental expense	144,317	137,243	137,834
Consolidated NOI	231,211	214,074	209,345
Operating Segments | Multifamily
Segment Reporting Information [Line Items]
Property rentals	85,809	63,401	53,071
Tenant reimbursements	5,012	3,454	2,790
Total rental revenue	90,821	66,855	55,861
Property operating	24,297	17,238	14,606
Real estate taxes	10,940	6,993	6,022
Total rental expense	35,237	24,231	20,628
Consolidated NOI	55,584	42,624	35,233
Operating Segments | Other
Segment Reporting Information [Line Items]
Property rentals	10,508	23,234	27,504
Tenant reimbursements	658	846	2,178
Total rental revenue	11,166	24,080	29,682
Property operating	8,528	7,216	9,268
Real estate taxes	5,011	4,676	7,373
Total rental expense	13,539	11,892	16,641
Consolidated NOI	(2,373)	12,188	13,041
Elimination of Intersegment Activity
Segment Reporting Information [Line Items]
Property rentals	(2,905)	(2,996)	(2,436)
Tenant reimbursements	0	0	0
Total rental revenue	(2,905)	(2,996)	(2,436)
Property operating	(15,604)	(15,278)	(14,718)
Real estate taxes	0	0	0
Total rental expense	(15,604)	(15,278)	(14,718)
Consolidated NOI	$ 12,699	$ 12,282	$ 12,282

Segment Information - Summary97

Segment Information - Summary of Certain Balance Sheet Data by Segment (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Real estate, at cost	$ 6,025,797	$ 4,155,391
Investments in and advances to unconsolidated real estate ventures	261,811	45,776
Total assets	6,071,807	3,660,640
Operating Segments | Office
Segment Reporting Information [Line Items]
Real estate, at cost	3,955,013	2,798,946
Investments in and advances to unconsolidated real estate ventures	124,659	45,647
Total assets	3,542,977	2,388,396
Operating Segments | Multifamily
Segment Reporting Information [Line Items]
Real estate, at cost	1,476,423	959,404
Investments in and advances to unconsolidated real estate ventures	98,835	0
Total assets	1,434,999	873,157
Operating Segments | Other
Segment Reporting Information [Line Items]
Real estate, at cost	594,361	397,041
Investments in and advances to unconsolidated real estate ventures	38,317	129
Total assets	1,299,085	399,087
Elimination of Intersegment Activity
Segment Reporting Information [Line Items]
Real estate, at cost	0	0
Investments in and advances to unconsolidated real estate ventures	0	0
Total assets	$ (205,254)	$ 0

Commitments and Contingencies -

Commitments and Contingencies - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
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	766,000,000
Additional capital funding committed amount	49,300,000
Rental expense related to non-cancelable operating and capital leases	4,700,000	$ 2,100,000	$ 1,900,000
Consolidated Properties
Real Estate Properties [Line Items]
Purchase obligation	676,000,000
Principal payment guarantees	91,500,000
Unconsolidated Properties
Real Estate Properties [Line Items]
Purchase obligation	90,000,000
Principal payment guarantees	$ 31,000,000
Minimum
Real Estate Properties [Line Items]
Commitment amortization period	2 years
Minimum | Unconsolidated Properties
Real Estate Properties [Line Items]
Commitment amortization period	2 years
Maximum
Real Estate Properties [Line Items]
Commitment amortization period	3 years
Maximum | Unconsolidated Properties
Real Estate Properties [Line Items]
Commitment amortization period	3 years

Commitments and Contingencies99

Commitments and Contingencies - Summary of Future Minimum Rental Payments (Details) $ in Thousands	Dec. 31, 2017USD ($)
Commitments and Contingencies Disclosure [Abstract]
2,018	$ 13,686
2,019	14,073
2,020	13,866
2,021	13,594
2,022	12,845
Thereafter	697,903
Total	$ 765,967

Transactions with Vornado an100

Transactions with Vornado and Related Parties (Details) ft² in Thousands	Jul. 18, 2017USD ($)	Jul. 17, 2017USD ($)	Aug. 12, 2014USD ($)	Jun. 30, 2016USD ($)ft²	Dec. 31, 2017USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Aug. 31, 2014USD ($)ft²
Related Party Transaction [Line Items]
Proceeds from repayment of receivable from former parent						$ 75,000,000	$ 4,000,000	$ 7,000,000
Receivable from former parent					$ 0	0	75,062,000
Proceeds from credit facility						115,751,000	0	0
Corporate and other						47,131,000	48,753,000	44,424,000
Universal Buildings, Washington DC
Related Party Transaction [Line Items]
Area of real estate property (in square feet) | ft²									687
Bowen Building, Washington DC
Related Party Transaction [Line Items]
Area of real estate property (in square feet) | ft²				231
Financing of the Universal Buildings
Related Party Transaction [Line Items]
Debt instrument, face amount									$ 185,000,000
Affiliate | Vornado | Vornado's revolving credit facility
Related Party Transaction [Line Items]
Interest expense to Vornado					$ 1,100,000	1,300,000
Proceeds from credit facility				$ 115,600,000
Affiliate | Vornado | Mortgage loan secured by Bowen Building
Related Party Transaction [Line Items]
Repayment of mortgage loan				115,000,000
Accrued interest on mortgage loan				$ 608,000
Affiliate | Legacy JBG Funds
Related Party Transaction [Line Items]
Corporate and other						2,300,000
Affiliate | Allocations of centralized corporate costs | Vornado
Related Party Transaction [Line Items]
Allocated amounts included in general and administrative expense						13,000,000	20,700,000	20,000,000
Affiliate | Financing transactions | Vornado | Financing of the Universal Buildings
Related Party Transaction [Line Items]
Loan to Vornado			$ 86,000,000
Proceeds from repayment of receivable from former parent							4,000,000	7,000,000
Interest Income on loan receivable from Vornado						$ 1,800,000	3,300,000	3,000,000
Affiliate | Financing transactions | Vornado | Financing of the Universal Buildings | LIBOR
Related Party Transaction [Line Items]
Mortgage loan interest rate						2.90%
Affiliate | Financing transactions | Vornado | Note agreement for development of Bartlett
Related Party Transaction [Line Items]
Debt instrument, face amount	$ 170,000,000
Amount outstanding on note agreements with Vornado							166,500,000
Interest expense to Vornado						$ 4,100,000	4,100,000	846,000
Affiliate | Supervise cleaning, engineering and security services | BMS
Related Party Transaction [Line Items]
Related party transaction amount						13,600,000	$ 12,100,000	$ 12,400,000
Affiliate | Separation and Combination transaction | Vornado
Related Party Transaction [Line Items]
Transaction services, initial period (in months)	2 years
Expenses from related parties						2,200,000
Revenue from related parties						779,000
Affiliate | Fees from Legacy JBG Funds | Legacy JBG Funds
Related Party Transaction [Line Items]
Real estate service revenue						19,900,000
Trustee | Consulting agreement
Related Party Transaction [Line Items]
Transaction services, initial period (in months)		24 months
Expenses from related parties						16,400,000
Related party transaction, monthly amount		$ 169,400
JBG Companies
Related Party Transaction [Line Items]
Liability incurred in connection with the Combination	$ 4,100,000					$ 3,000,000

Quarterly Financial Data (un101

Quarterly Financial Data (unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	Jul. 18, 2017	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Business Acquisition [Line Items]
Total revenue		$ 156,371	$ 152,350	$ 118,020	$ 116,272	$ 122,039	$ 123,357	$ 116,339	$ 116,784	$ 543,013	$ 478,519	$ 470,607
Net income (loss)		(18,752)	(77,991)	11,341	6,318	12,630	21,014	16,783	11,547	(79,084)	61,974	49,628
Net income (loss) attributable to common shareholders		$ (16,418)	$ (69,831)	$ 11,341	$ 6,318	$ 12,630	$ 21,014	$ 16,783	$ 11,547	$ (73,408)	$ 61,974	$ 49,628
Earnings (loss) per share:
Basic (in dollars per share)		$ (0.15)	$ (0.61)	$ 0.11	$ 0.06	$ 0.13	$ 0.21	$ 0.17	$ 0.11	$ (0.70)	$ 0.62	$ 0.49
Diluted (in dollars per share)		$ (0.15)	$ (0.61)	$ 0.11	$ 0.06	$ 0.13	$ 0.21	$ 0.17	$ 0.11	$ (0.70)	$ 0.62	$ 0.49
Transaction and other costs										$ 127,739	$ 6,476	$ 0
Gain on bargain purchase										24,376	0	0
Share-based compensation related to Formation Transaction										29,251	0	$ 0
JBG Companies
Earnings (loss) per share:
Transaction and other costs		$ 12,600	$ 104,100			$ 4,900				$ 127,700	$ 6,500
Gain on bargain purchase	$ 24,376		27,800
Share-based compensation related to Formation Transaction		14,800	$ 14,400
Reduction to gain on bargain purchase		$ (3,400)

Subsequent Events (Details)

Subsequent Events (Details) - USD ($) $ in Thousands	Aug. 01, 2017	Jul. 18, 2017	Feb. 28, 2018	Jan. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Subsequent Event [Line Items]
Proceeds from credit facility					$ 115,751	$ 0	$ 0
Subsequent Event
Subsequent Event [Line Items]
Aggregate notional value of shares granted			$ 21,100
Formation Units
Subsequent Event [Line Items]
Equity grants (in shares)		2,700,000			2,680,552
Aggregate notional value of shares granted		$ 100,000
Formation Units | Subsequent Event
Subsequent Event [Line Items]
Equity grants (in shares)			61,309
Time-Based LTIP Units
Subsequent Event [Line Items]
Equity grants (in shares)	302,518
Time-Based LTIP Units | Subsequent Event
Subsequent Event [Line Items]
Equity grants (in shares)			357,922
Performance-Based LTIP Units
Subsequent Event [Line Items]
Equity grants (in shares)	605,072				605,072
Performance-Based LTIP Units | Subsequent Event
Subsequent Event [Line Items]
Equity grants (in shares)			553,589
Marriott Wardman Park Hotel | Subsequent Event
Subsequent Event [Line Items]
Payments to acquire interest in joint venture				$ 10,100
Ownership Interest				16.67%
Marriott Wardman Park Hotel | PacLife | Subsequent Event
Subsequent Event [Line Items]
Payments to acquire interest in joint venture				$ 40,300
Ownership Interest				66.67%
Marriott Wardman Park Hotel | Legacy JBG Funds | Subsequent Event
Subsequent Event [Line Items]
Ownership Interest				47.64%
1900 N Street | Subsequent Event
Subsequent Event [Line Items]
Ownership Interest			100.00%
Ownership interest after contributions are funded			55.00%
1900 N Street | CPPIB | Subsequent Event
Subsequent Event [Line Items]
Ownership Interest			45.00%
Commitment amount			$ 101,000
Reston, Virginia | Office Assets
Subsequent Event [Line Items]
Carrying value of office asset					$ 87,900
Reston, Virginia | Office Assets | Subsequent Event
Subsequent Event [Line Items]
Gross sales price				$ 95,000
Line of credit | Tranche A-1 Term Loan | Subsequent Event
Subsequent Event [Line Items]
Proceeds from credit facility				$ 50,000

Schedule II - Valuation and 103

Schedule II - Valuation and Qualifying Accounts (Details) - Allowance for Doubtful Accounts - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	$ 4,526	$ 4,431	$ 2,514
Additions Charged Against Operations	3,807	751	1,407
Adjustments to Valuation Accounts	0	0	0
Uncollectible Accounts Written‑off	(2,048)	(656)	510
Balance at End of Year	$ 6,285	$ 4,526	$ 4,431

Schedule III - Real Estate a104

Schedule III - Real Estate and Accumulated Deprecation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2017
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				$ 2,035,959
Land and Improvements				1,340,744
Buildings and Improvements				2,922,442
Costs Capitalized Subsequent to Acquisition(2)				1,762,611
Land and Improvements				1,376,587
Buildings and Improvements				4,649,210
Total	$ 4,155,391	$ 4,038,206	$ 3,809,213	6,025,797
Accumulated Depreciation and Amortization	930,769	908,233	797,806	1,011,330
Cost of real estate for federal income tax purposes				3,500,000
Real Estate:
Balance at beginning of the year	4,155,391	4,038,206	3,809,213
Land and improvements	428,702	0	0
Buildings and improvements	1,489,409	217,261	252,113
Held for sale	8,293	0	0
Less: Assets written‑off	(55,998)	(100,076)	(23,120)
Balance at end of the year	6,025,797	4,155,391	4,038,206
Accumulated Depreciation:
Balance at beginning of period	930,769	908,233	797,806
Additions charged to operating expenses	136,559	122,612	133,582
Less: Accumulated depreciation on assets written‑off	(55,998)	(100,076)	(23,155)
Balance at end of period	1,011,330	$ 930,769	$ 908,233
Universal Buildings
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				184,357
Land and Improvements				69,393
Buildings and Improvements				143,320
Costs Capitalized Subsequent to Acquisition(2)				22,547
Land and Improvements				68,612
Buildings and Improvements				166,648
Total	235,260			235,260
Accumulated Depreciation and Amortization	48,187			48,187
Real Estate:
Balance at end of the year	235,260
Accumulated Depreciation:
Balance at end of period	48,187
2101 L Street
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				140,493
Land and Improvements				32,815
Buildings and Improvements				51,642
Costs Capitalized Subsequent to Acquisition(2)				83,766
Land and Improvements				39,768
Buildings and Improvements				128,455
Total	168,223			168,223
Accumulated Depreciation and Amortization	40,822			40,822
Real Estate:
Balance at end of the year	168,223
Accumulated Depreciation:
Balance at end of period	40,822
Bowen Building
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				0
Land and Improvements				30,077
Buildings and Improvements				98,962
Costs Capitalized Subsequent to Acquisition(2)				6,238
Land and Improvements				30,176
Buildings and Improvements				105,101
Total	135,277			135,277
Accumulated Depreciation and Amortization	32,854			32,854
Real Estate:
Balance at end of the year	135,277
Accumulated Depreciation:
Balance at end of period	32,854
1730 M Street
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				0
Land and Improvements				10,095
Buildings and Improvements				17,541
Costs Capitalized Subsequent to Acquisition(2)				16,111
Land and Improvements				10,687
Buildings and Improvements				33,060
Total	43,747			43,747
Accumulated Depreciation and Amortization	12,537			12,537
Real Estate:
Balance at end of the year	43,747
Accumulated Depreciation:
Balance at end of period	12,537
1233 20th Street
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				42,684
Land and Improvements				30,505
Buildings and Improvements				23,130
Costs Capitalized Subsequent to Acquisition(2)				338
Land and Improvements				30,505
Buildings and Improvements				23,468
Total	53,973			53,973
Accumulated Depreciation and Amortization	735			735
Real Estate:
Balance at end of the year	53,973
Accumulated Depreciation:
Balance at end of period	735
Executive Tower
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				0
Land and Improvements				33,481
Buildings and Improvements				67,363
Costs Capitalized Subsequent to Acquisition(2)				9,306
Land and Improvements				34,178
Buildings and Improvements				75,972
Total	110,150			110,150
Accumulated Depreciation and Amortization	13,180			13,180
Real Estate:
Balance at end of the year	110,150
Accumulated Depreciation:
Balance at end of period	13,180
1600 K Street
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				0
Land and Improvements				19,870
Buildings and Improvements				10,308
Costs Capitalized Subsequent to Acquisition(2)				193
Land and Improvements				19,870
Buildings and Improvements				10,501
Total	30,371			30,371
Accumulated Depreciation and Amortization	402			402
Real Estate:
Balance at end of the year	30,371
Accumulated Depreciation:
Balance at end of period	402
Courthouse Plaza 1 and 2
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				2,000
Land and Improvements				0
Buildings and Improvements				105,475
Costs Capitalized Subsequent to Acquisition(2)				56,173
Land and Improvements				0
Buildings and Improvements				161,648
Total	161,648			161,648
Accumulated Depreciation and Amortization	67,974			67,974
Real Estate:
Balance at end of the year	161,648
Accumulated Depreciation:
Balance at end of period	67,974
2345 Crystal Drive
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				0
Land and Improvements				23,126
Buildings and Improvements				93,918
Costs Capitalized Subsequent to Acquisition(2)				35,612
Land and Improvements				23,546
Buildings and Improvements				129,110
Total	152,656			152,656
Accumulated Depreciation and Amortization	54,253			54,253
Real Estate:
Balance at end of the year	152,656
Accumulated Depreciation:
Balance at end of period	54,253
2121 Crystal Drive
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				139,134
Land and Improvements				21,503
Buildings and Improvements				87,329
Costs Capitalized Subsequent to Acquisition(2)				47,790
Land and Improvements				21,934
Buildings and Improvements				134,688
Total	156,622			156,622
Accumulated Depreciation and Amortization	65,256			65,256
Real Estate:
Balance at end of the year	156,622
Accumulated Depreciation:
Balance at end of period	65,256
1550 Crystal Drive
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				0
Land and Improvements				22,182
Buildings and Improvements				70,525
Costs Capitalized Subsequent to Acquisition(2)				19,796
Land and Improvements				21,585
Buildings and Improvements				90,918
Total	112,503			112,503
Accumulated Depreciation and Amortization	37,886			37,886
Real Estate:
Balance at end of the year	112,503
Accumulated Depreciation:
Balance at end of period	37,886
RTC - West
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				107,720
Land and Improvements				30,326
Buildings and Improvements				134,108
Costs Capitalized Subsequent to Acquisition(2)				(110)
Land and Improvements				30,397
Buildings and Improvements				133,927
Total	164,324			164,324
Accumulated Depreciation and Amortization	3,330			3,330
Real Estate:
Balance at end of the year	164,324
Accumulated Depreciation:
Balance at end of period	3,330
2231 Crystal Drive
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				0
Land and Improvements				20,611
Buildings and Improvements				83,705
Costs Capitalized Subsequent to Acquisition(2)				18,856
Land and Improvements				21,001
Buildings and Improvements				102,171
Total	123,172			123,172
Accumulated Depreciation and Amortization	38,807			38,807
Real Estate:
Balance at end of the year	123,172
Accumulated Depreciation:
Balance at end of period	38,807
2011 Crystal Drive
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				0
Land and Improvements				18,940
Buildings and Improvements				76,921
Costs Capitalized Subsequent to Acquisition(2)				33,139
Land and Improvements				18,871
Buildings and Improvements				110,129
Total	129,000			129,000
Accumulated Depreciation and Amortization	45,263			45,263
Real Estate:
Balance at end of the year	129,000
Accumulated Depreciation:
Balance at end of period	45,263
2451 Crystal Drive
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				0
Land and Improvements				16,755
Buildings and Improvements				68,047
Costs Capitalized Subsequent to Acquisition(2)				27,307
Land and Improvements				17,090
Buildings and Improvements				95,019
Total	112,109			112,109
Accumulated Depreciation and Amortization	35,934			35,934
Real Estate:
Balance at end of the year	112,109
Accumulated Depreciation:
Balance at end of period	35,934
Commerce Executive
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				0
Land and Improvements				13,401
Buildings and Improvements				58,705
Costs Capitalized Subsequent to Acquisition(2)				26,122
Land and Improvements				13,140
Buildings and Improvements				85,088
Total	98,228			98,228
Accumulated Depreciation and Amortization	33,829			33,829
Real Estate:
Balance at end of the year	98,228
Accumulated Depreciation:
Balance at end of period	33,829
1235 S. Clark Street
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				78,000
Land and Improvements				15,826
Buildings and Improvements				56,090
Costs Capitalized Subsequent to Acquisition(2)				27,075
Land and Improvements				16,189
Buildings and Improvements				82,802
Total	98,991			98,991
Accumulated Depreciation and Amortization	30,358			30,358
Real Estate:
Balance at end of the year	98,991
Accumulated Depreciation:
Balance at end of period	30,358
241 18th Street S.
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				0
Land and Improvements				13,867
Buildings and Improvements				54,169
Costs Capitalized Subsequent to Acquisition(2)				25,164
Land and Improvements				14,894
Buildings and Improvements				78,306
Total	93,200			93,200
Accumulated Depreciation and Amortization	30,915			30,915
Real Estate:
Balance at end of the year	93,200
Accumulated Depreciation:
Balance at end of period	30,915
251 18th Street S.
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				35,792
Land and Improvements				12,305
Buildings and Improvements				49,360
Costs Capitalized Subsequent to Acquisition(2)				50,928
Land and Improvements				12,809
Buildings and Improvements				99,784
Total	112,593			112,593
Accumulated Depreciation and Amortization	34,678			34,678
Real Estate:
Balance at end of the year	112,593
Accumulated Depreciation:
Balance at end of period	34,678
1215 S. Clark Street
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				34,299
Land and Improvements				13,636
Buildings and Improvements				48,380
Costs Capitalized Subsequent to Acquisition(2)				54,196
Land and Improvements				13,926
Buildings and Improvements				102,286
Total	116,212			116,212
Accumulated Depreciation and Amortization	27,373			27,373
Real Estate:
Balance at end of the year	116,212
Accumulated Depreciation:
Balance at end of period	27,373
201 12th Street S.
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				0
Land and Improvements				14,766
Buildings and Improvements				52,750
Costs Capitalized Subsequent to Acquisition(2)				22,680
Land and Improvements				15,036
Buildings and Improvements				75,160
Total	90,196			90,196
Accumulated Depreciation and Amortization	27,838			27,838
Real Estate:
Balance at end of the year	90,196
Accumulated Depreciation:
Balance at end of period	27,838
800 North Glebe Road
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				107,500
Land and Improvements				28,168
Buildings and Improvements				140,983
Costs Capitalized Subsequent to Acquisition(2)				2,182
Land and Improvements				28,168
Buildings and Improvements				143,165
Total	171,333			171,333
Accumulated Depreciation and Amortization	2,737			2,737
Real Estate:
Balance at end of the year	171,333
Accumulated Depreciation:
Balance at end of period	2,737
1225 S. Clark Street
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				0
Land and Improvements				11,176
Buildings and Improvements				43,495
Costs Capitalized Subsequent to Acquisition(2)				19,649
Land and Improvements				11,413
Buildings and Improvements				62,907
Total	74,320			74,320
Accumulated Depreciation and Amortization	23,247			23,247
Real Estate:
Balance at end of the year	74,320
Accumulated Depreciation:
Balance at end of period	23,247
2200 Crystal Drive
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				0
Land and Improvements				13,104
Buildings and Improvements				30,050
Costs Capitalized Subsequent to Acquisition(2)				32,798
Land and Improvements				13,378
Buildings and Improvements				62,574
Total	75,952			75,952
Accumulated Depreciation and Amortization	18,075			18,075
Real Estate:
Balance at end of the year	75,952
Accumulated Depreciation:
Balance at end of period	18,075
1901 South Bell Street
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				0
Land and Improvements				11,669
Buildings and Improvements				36,918
Costs Capitalized Subsequent to Acquisition(2)				22,584
Land and Improvements				11,669
Buildings and Improvements				59,502
Total	71,171			71,171
Accumulated Depreciation and Amortization	24,931			24,931
Real Estate:
Balance at end of the year	71,171
Accumulated Depreciation:
Balance at end of period	24,931
2100 Crystal Drive
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				0
Land and Improvements				10,287
Buildings and Improvements				23,590
Costs Capitalized Subsequent to Acquisition(2)				31,712
Land and Improvements				10,520
Buildings and Improvements				55,069
Total	65,589			65,589
Accumulated Depreciation and Amortization	22,490			22,490
Real Estate:
Balance at end of the year	65,589
Accumulated Depreciation:
Balance at end of period	22,490
200 12th Street S.
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				17,227
Land and Improvements				8,016
Buildings and Improvements				30,552
Costs Capitalized Subsequent to Acquisition(2)				19,423
Land and Improvements				8,186
Buildings and Improvements				49,805
Total	57,991			57,991
Accumulated Depreciation and Amortization	18,490			18,490
Real Estate:
Balance at end of the year	57,991
Accumulated Depreciation:
Balance at end of period	18,490
2001 Jefferson Davis Highway
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				0
Land and Improvements				7,300
Buildings and Improvements				16,746
Costs Capitalized Subsequent to Acquisition(2)				11,297
Land and Improvements				7,281
Buildings and Improvements				28,062
Total	35,343			35,343
Accumulated Depreciation and Amortization	10,135			10,135
Real Estate:
Balance at end of the year	35,343
Accumulated Depreciation:
Balance at end of period	10,135
Summit I
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				29,500
Land and Improvements				7,317
Buildings and Improvements				30,626
Costs Capitalized Subsequent to Acquisition(2)				379
Land and Improvements				7,317
Buildings and Improvements				31,005
Total	38,322			38,322
Accumulated Depreciation and Amortization	662			662
Real Estate:
Balance at end of the year	38,322
Accumulated Depreciation:
Balance at end of period	662
Summit II
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				29,500
Land and Improvements				5,535
Buildings and Improvements				28,463
Costs Capitalized Subsequent to Acquisition(2)				332
Land and Improvements				5,535
Buildings and Improvements				28,795
Total	34,330			34,330
Accumulated Depreciation and Amortization	741			741
Real Estate:
Balance at end of the year	34,330
Accumulated Depreciation:
Balance at end of period	741
1800 South Bell Street
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				0
Land and Improvements				0
Buildings and Improvements				28,702
Costs Capitalized Subsequent to Acquisition(2)				7,220
Land and Improvements				0
Buildings and Improvements				35,922
Total	35,922			35,922
Accumulated Depreciation and Amortization	14,835			14,835
Real Estate:
Balance at end of the year	35,922
Accumulated Depreciation:
Balance at end of period	14,835
Crystal City Shops at 2100
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				0
Land and Improvements				4,059
Buildings and Improvements				9,309
Costs Capitalized Subsequent to Acquisition(2)				5,229
Land and Improvements				4,049
Buildings and Improvements				14,548
Total	18,597			18,597
Accumulated Depreciation and Amortization	5,611			5,611
Real Estate:
Balance at end of the year	18,597
Accumulated Depreciation:
Balance at end of period	5,611
Wiehle Avenue Office Building
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				0
Land and Improvements				0
Buildings and Improvements				96
Costs Capitalized Subsequent to Acquisition(2)				0
Land and Improvements				0
Buildings and Improvements				96
Total	96			96
Accumulated Depreciation and Amortization	48			48
Real Estate:
Balance at end of the year	96
Accumulated Depreciation:
Balance at end of period	48
1831 Wiehle Avenue
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				0
Land and Improvements				0
Buildings and Improvements				0
Costs Capitalized Subsequent to Acquisition(2)				24
Land and Improvements				0
Buildings and Improvements				24
Total	24			24
Accumulated Depreciation and Amortization	2			2
Real Estate:
Balance at end of the year	24
Accumulated Depreciation:
Balance at end of period	2
Crystal Drive Retail
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				0
Land and Improvements				0
Buildings and Improvements				20,465
Costs Capitalized Subsequent to Acquisition(2)				6,034
Land and Improvements				55
Buildings and Improvements				26,444
Total	26,499			26,499
Accumulated Depreciation and Amortization	12,133			12,133
Real Estate:
Balance at end of the year	26,499
Accumulated Depreciation:
Balance at end of period	12,133
7200 Wisconsin Avenue
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				83,130
Land and Improvements				34,683
Buildings and Improvements				92,059
Costs Capitalized Subsequent to Acquisition(2)				885
Land and Improvements				34,683
Buildings and Improvements				92,944
Total	127,627			127,627
Accumulated Depreciation and Amortization	1,763			1,763
Real Estate:
Balance at end of the year	127,627
Accumulated Depreciation:
Balance at end of period	1,763
One Democracy Plaza
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				0
Land and Improvements				0
Buildings and Improvements				33,628
Costs Capitalized Subsequent to Acquisition(2)				6,572
Land and Improvements				0
Buildings and Improvements				40,200
Total	40,200			40,200
Accumulated Depreciation and Amortization	21,915			21,915
Real Estate:
Balance at end of the year	40,200
Accumulated Depreciation:
Balance at end of period	21,915
4749 Bethesda Avenue Retail
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				0
Land and Improvements				0
Buildings and Improvements				11,830
Costs Capitalized Subsequent to Acquisition(2)				2,664
Land and Improvements				0
Buildings and Improvements				14,494
Total	14,494			14,494
Accumulated Depreciation and Amortization	0			0
Real Estate:
Balance at end of the year	14,494
Accumulated Depreciation:
Balance at end of period	0
RTC - West Retail
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				0
Land and Improvements				2,894
Buildings and Improvements				0
Costs Capitalized Subsequent to Acquisition(2)				7,011
Land and Improvements				2,894
Buildings and Improvements				7,011
Total	9,905			9,905
Accumulated Depreciation and Amortization	103			103
Real Estate:
Balance at end of the year	9,905
Accumulated Depreciation:
Balance at end of period	103
1900 N Street
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				0
Land and Improvements				0
Buildings and Improvements				8,865
Costs Capitalized Subsequent to Acquisition(2)				86,336
Land and Improvements				0
Buildings and Improvements				95,201
Total	95,201			95,201
Accumulated Depreciation and Amortization	0			0
Real Estate:
Balance at end of the year	95,201
Accumulated Depreciation:
Balance at end of period	0
CEB Tower at Central Place
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				178,783
Land and Improvements				0
Buildings and Improvements				230,280
Costs Capitalized Subsequent to Acquisition(2)				117,898
Land and Improvements				0
Buildings and Improvements				348,178
Total	348,178			348,178
Accumulated Depreciation and Amortization	0			0
Real Estate:
Balance at end of the year	348,178
Accumulated Depreciation:
Balance at end of period	0
4747 Bethesda Avenue
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				0
Land and Improvements				0
Buildings and Improvements				10,040
Costs Capitalized Subsequent to Acquisition(2)				46,782
Land and Improvements				0
Buildings and Improvements				56,822
Total	56,822			56,822
Accumulated Depreciation and Amortization	0			0
Real Estate:
Balance at end of the year	56,822
Accumulated Depreciation:
Balance at end of period	0
Fort Totten Square
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				73,600
Land and Improvements				24,390
Buildings and Improvements				90,404
Costs Capitalized Subsequent to Acquisition(2)				566
Land and Improvements				24,390
Buildings and Improvements				90,970
Total	115,360			115,360
Accumulated Depreciation and Amortization	1,785			1,785
Real Estate:
Balance at end of the year	115,360
Accumulated Depreciation:
Balance at end of period	1,785
WestEnd25
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				99,456
Land and Improvements				67,049
Buildings and Improvements				5,039
Costs Capitalized Subsequent to Acquisition(2)				109,922
Land and Improvements				68,201
Buildings and Improvements				113,809
Total	182,010			182,010
Accumulated Depreciation and Amortization	23,983			23,983
Real Estate:
Balance at end of the year	182,010
Accumulated Depreciation:
Balance at end of period	23,983
RiverHouse Apartments
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				307,710
Land and Improvements				118,421
Buildings and Improvements				125,078
Costs Capitalized Subsequent to Acquisition(2)				82,825
Land and Improvements				138,763
Buildings and Improvements				187,561
Total	326,324			326,324
Accumulated Depreciation and Amortization	56,476			56,476
Real Estate:
Balance at end of the year	326,324
Accumulated Depreciation:
Balance at end of period	56,476
The Bartlett
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				220,000
Land and Improvements				41,687
Buildings and Improvements				0
Costs Capitalized Subsequent to Acquisition(2)				224,805
Land and Improvements				41,687
Buildings and Improvements				224,805
Total	266,492			266,492
Accumulated Depreciation and Amortization	10,074			10,074
Real Estate:
Balance at end of the year	266,492
Accumulated Depreciation:
Balance at end of period	10,074
220 20th Street
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				0
Land and Improvements				8,434
Buildings and Improvements				19,340
Costs Capitalized Subsequent to Acquisition(2)				99,259
Land and Improvements				8,693
Buildings and Improvements				118,340
Total	127,033			127,033
Accumulated Depreciation and Amortization	27,749			27,749
Real Estate:
Balance at end of the year	127,033
Accumulated Depreciation:
Balance at end of period	27,749
2221 South Clark Street
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				0
Land and Improvements				7,405
Buildings and Improvements				16,981
Costs Capitalized Subsequent to Acquisition(2)				41,598
Land and Improvements				7,386
Buildings and Improvements				58,598
Total	65,984			65,984
Accumulated Depreciation and Amortization	4,109			4,109
Real Estate:
Balance at end of the year	65,984
Accumulated Depreciation:
Balance at end of period	4,109
Falkland Chase - South & West
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				41,976
Land and Improvements				18,530
Buildings and Improvements				44,232
Costs Capitalized Subsequent to Acquisition(2)				107
Land and Improvements				18,530
Buildings and Improvements				44,339
Total	62,869			62,869
Accumulated Depreciation and Amortization	910			910
Real Estate:
Balance at end of the year	62,869
Accumulated Depreciation:
Balance at end of period	910
Falkland Chase - North
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				22,566
Land and Improvements				9,810
Buildings and Improvements				22,706
Costs Capitalized Subsequent to Acquisition(2)				6
Land and Improvements				9,810
Buildings and Improvements				22,712
Total	32,522			32,522
Accumulated Depreciation and Amortization	477			477
Real Estate:
Balance at end of the year	32,522
Accumulated Depreciation:
Balance at end of period	477
West Half
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				1,338
Land and Improvements				0
Buildings and Improvements				17,902
Costs Capitalized Subsequent to Acquisition(2)				69,424
Land and Improvements				0
Buildings and Improvements				87,326
Total	87,326			87,326
Accumulated Depreciation and Amortization	0			0
Real Estate:
Balance at end of the year	87,326
Accumulated Depreciation:
Balance at end of period	0
965 Florida Avenue
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				0
Land and Improvements				0
Buildings and Improvements				0
Costs Capitalized Subsequent to Acquisition(2)				22,665
Land and Improvements				0
Buildings and Improvements				22,665
Total	22,665			22,665
Accumulated Depreciation and Amortization	0			0
Real Estate:
Balance at end of the year	22,665
Accumulated Depreciation:
Balance at end of period	0
1221 Van Street
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				59,194
Land and Improvements				0
Buildings and Improvements				63,775
Costs Capitalized Subsequent to Acquisition(2)				46,834
Land and Improvements				0
Buildings and Improvements				110,609
Total	110,609			110,609
Accumulated Depreciation and Amortization	1			1
Real Estate:
Balance at end of the year	110,609
Accumulated Depreciation:
Balance at end of period	1
Atlantic Plumbing C
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				0
Land and Improvements				0
Buildings and Improvements				13,952
Costs Capitalized Subsequent to Acquisition(2)				63,269
Land and Improvements				0
Buildings and Improvements				77,221
Total	77,221			77,221
Accumulated Depreciation and Amortization	0			0
Real Estate:
Balance at end of the year	77,221
Accumulated Depreciation:
Balance at end of period	0
North End Retail
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				0
Land and Improvements				5,847
Buildings and Improvements				9,333
Costs Capitalized Subsequent to Acquisition(2)				(107)
Land and Improvements				5,847
Buildings and Improvements				9,226
Total	15,073			15,073
Accumulated Depreciation and Amortization	179			179
Real Estate:
Balance at end of the year	15,073
Accumulated Depreciation:
Balance at end of period	179
Vienna Retail
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				0
Land and Improvements				1,763
Buildings and Improvements				641
Costs Capitalized Subsequent to Acquisition(2)				41
Land and Improvements				1,763
Buildings and Improvements				682
Total	2,445			2,445
Accumulated Depreciation and Amortization	213			213
Real Estate:
Balance at end of the year	2,445
Accumulated Depreciation:
Balance at end of period	213
Crystal City Marriott Hotel
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				0
Land and Improvements				8,000
Buildings and Improvements				47,191
Costs Capitalized Subsequent to Acquisition(2)				12,595
Land and Improvements				8,224
Buildings and Improvements				59,562
Total	67,786			67,786
Accumulated Depreciation and Amortization	20,529			20,529
Real Estate:
Balance at end of the year	67,786
Accumulated Depreciation:
Balance at end of period	20,529
Metropolitan Park 6-8
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				0
Land and Improvements				65,259
Buildings and Improvements				1,326
Costs Capitalized Subsequent to Acquisition(2)				26,574
Land and Improvements				82,898
Buildings and Improvements				10,261
Total	93,159			93,159
Accumulated Depreciation and Amortization	27			27
Real Estate:
Balance at end of the year	93,159
Accumulated Depreciation:
Balance at end of period	27
Pen Place - Land Parcel
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				0
Land and Improvements				104,473
Buildings and Improvements				55
Costs Capitalized Subsequent to Acquisition(2)				(32,322)
Land and Improvements				61,970
Buildings and Improvements				10,236
Total	72,206			72,206
Accumulated Depreciation and Amortization	0			0
Real Estate:
Balance at end of the year	72,206
Accumulated Depreciation:
Balance at end of period	0
1700 M Street Dev
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				0
Land and Improvements				34,178
Buildings and Improvements				46,938
Costs Capitalized Subsequent to Acquisition(2)				(26,487)
Land and Improvements				34,183
Buildings and Improvements				20,446
Total	54,629			54,629
Accumulated Depreciation and Amortization	0			0
Real Estate:
Balance at end of the year	54,629
Accumulated Depreciation:
Balance at end of period	0
Capitol Point - North
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				0
Land and Improvements				32,730
Buildings and Improvements				0
Costs Capitalized Subsequent to Acquisition(2)				147
Land and Improvements				32,846
Buildings and Improvements				31
Total	32,877			32,877
Accumulated Depreciation and Amortization	0			0
Real Estate:
Balance at end of the year	32,877
Accumulated Depreciation:
Balance at end of period	0
Potomac Yard Land Bay G - Parcels A - F
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				0
Land and Improvements				20,318
Buildings and Improvements				0
Costs Capitalized Subsequent to Acquisition(2)				132
Land and Improvements				20,318
Buildings and Improvements				132
Total	20,450			20,450
Accumulated Depreciation and Amortization	0			0
Real Estate:
Balance at end of the year	20,450
Accumulated Depreciation:
Balance at end of period	0
Square 649
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				0
Land and Improvements				15,550
Buildings and Improvements				6,451
Costs Capitalized Subsequent to Acquisition(2)				(2,328)
Land and Improvements				12,803
Buildings and Improvements				6,870
Total	19,673			19,673
Accumulated Depreciation and Amortization	367			367
Real Estate:
Balance at end of the year	19,673
Accumulated Depreciation:
Balance at end of period	367
Other Future Development Assets
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				0
Land and Improvements				140,919
Buildings and Improvements				112,653
Costs Capitalized Subsequent to Acquisition(2)				(9,091)
Land and Improvements				170,620
Buildings and Improvements				73,861
Total	244,481			244,481
Accumulated Depreciation and Amortization	62			62
Real Estate:
Balance at end of the year	244,481
Accumulated Depreciation:
Balance at end of period	62
Corporate
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				0
Land and Improvements				0
Buildings and Improvements				0
Costs Capitalized Subsequent to Acquisition(2)				21,939
Land and Improvements				0
Buildings and Improvements				21,939
Total	21,939			21,939
Accumulated Depreciation and Amortization	4,060			4,060
Real Estate:
Balance at end of the year	21,939
Accumulated Depreciation:
Balance at end of period	4,060
Properties Not Held For Sale
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				2,035,959
Land and Improvements				1,332,451
Buildings and Improvements				2,922,442
Costs Capitalized Subsequent to Acquisition(2)				1,762,611
Land and Improvements				1,368,294
Buildings and Improvements				4,649,210
Total	6,017,504			6,017,504
Accumulated Depreciation and Amortization	1,011,330			1,011,330
Real Estate:
Balance at end of the year	6,017,504
Accumulated Depreciation:
Balance at end of period	1,011,330
Summit II
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				0
Land and Improvements				1,699
Buildings and Improvements				0
Costs Capitalized Subsequent to Acquisition(2)				0
Land and Improvements				1,699
Buildings and Improvements				0
Total	1,699			1,699
Accumulated Depreciation and Amortization	0			0
Real Estate:
Balance at end of the year	1,699
Accumulated Depreciation:
Balance at end of period	0
Potomac Yard Land Bay G - Parcel G
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				0
Land and Improvements				6,594
Buildings and Improvements				0
Costs Capitalized Subsequent to Acquisition(2)				0
Land and Improvements				6,594
Buildings and Improvements				0
Total	6,594			6,594
Accumulated Depreciation and Amortization	0			0
Real Estate:
Balance at end of the year	6,594
Accumulated Depreciation:
Balance at end of period	0
Properties Held For Sale
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Encumbrances				0
Land and Improvements				8,293
Buildings and Improvements				0
Costs Capitalized Subsequent to Acquisition(2)				0
Land and Improvements				8,293
Buildings and Improvements				0
Total	8,293			8,293
Accumulated Depreciation and Amortization	0			$ 0
Real Estate:
Balance at end of the year	8,293
Accumulated Depreciation:
Balance at end of period	$ 0
Maximum
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Useful life	40 years

Uncategorized Items - jbgs-2017

Label	Element	Value
Dividends Payable, Common Shareholders	jbgs_DividendsPayableCommonShareholders	$ 0
Dividends Payable, Common Shareholders	jbgs_DividendsPayableCommonShareholders	0
Dividends Payable, Common Shareholders	jbgs_DividendsPayableCommonShareholders	26,540,000
Interest Payable	us-gaap_InterestPayableCurrentAndNoncurrent	0
Interest Payable	us-gaap_InterestPayableCurrentAndNoncurrent	0
Interest Payable	us-gaap_InterestPayableCurrentAndNoncurrent	3,714,000
Dividends Payable, Redeemable Noncontrolling Interest	jbgs_DividendsPayableRedeemableNoncontrollingInterest	0
Dividends Payable, Redeemable Noncontrolling Interest	jbgs_DividendsPayableRedeemableNoncontrollingInterest	0
Dividends Payable, Redeemable Noncontrolling Interest	jbgs_DividendsPayableRedeemableNoncontrollingInterest	$ 4,557,000