JBG SMITH Properties (JBGS) 10-K 25 Feb 20 2019 FY Annual report Financial data

Cover Page

Cover Page - USD ($) $ / shares in Units, $ in Billions	12 Months Ended
	Dec. 31, 2019	Feb. 20, 2020	Jun. 30, 2019
Cover page.
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2019
Document Transition Report	false
Entity File Number	001-37994
Entity Registrant Name	JBG SMITH PROPERTIES
Entity Incorporation, State or Country Code	MD
Entity Tax Identification Number	81-4307010
Entity Address, Address Line One	4747 Bethesda Avenue
Entity Address, City or Town	Bethesda
Entity Address, State or Province	MD
Entity Address, Postal Zip Code	20814
Entity Address, Address Line Two	Suite 200
City Area Code	240
Local Phone Number	333-3600
Title of 12(b) Security	Common Shares, par value $0.01 per share
Trading Symbol	JBGS
Security Exchange Name	NYSE
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		134,882,302
Entity Public Float			$ 5.1
Share Price			$ 39.34
Entity Central Index Key	0001689796
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Amendment Flag	false

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Real estate, at cost:
Land and improvements	$ 1,240,455	$ 1,371,874
Buildings and improvements	3,880,973	3,722,930
Construction in progress, including land	654,091	697,930
Real estate, at cost	5,775,519	5,792,734
Less accumulated depreciation	(1,119,571)	(1,051,875)
Real estate, net	4,655,948	4,740,859
Cash and cash equivalents	126,413	260,553
Restricted cash	16,103	138,979
Tenant and other receivables, net	52,941	46,568
Deferred rent receivable, net	169,721	143,473
Investments in and advances to unconsolidated real estate ventures	543,026	322,878
Other assets, net	253,687	264,994
Assets held for sale	168,412	78,981
TOTAL ASSETS	5,986,251	5,997,285
Liabilities:
Mortgages payable, net	1,125,777	1,838,381
Long-term Line of Credit	200,000	0
Unsecured term loans, net	297,295	297,129
Accounts payable and accrued expenses	157,702	130,960
Other liabilities, net	206,042	181,606
Liabilities related to assets held for sale	0	3,717
Total liabilities	1,986,816	2,451,793
Commitments and contingencies
Redeemable noncontrolling interests	612,758	558,140
Shareholders' equity:
Preferred shares, $0.01 par value - 200,000 shares authorized, none issued	0	0
Common shares, $0.01 par value - 500,000 shares authorized; 134,148 and 120,937 shares issued and outstanding as of December 31, 2019 and 2018	1,342	1,210
Additional paid-in capital	3,633,042	3,155,256
Accumulated deficit	(231,164)	(176,018)
Accumulated other comprehensive income (loss)	(16,744)	6,700
Total shareholders' equity of JBG SMITH Properties	3,386,476	2,987,148
Noncontrolling interests in consolidated subsidiaries	201	204
Total equity	3,386,677	2,987,352
TOTAL LIABILITIES, REDEEMABLE NONCONTROLLING INTERESTS AND EQUITY	$ 5,986,251	$ 5,997,285

Consolidated and Combined Balan

Consolidated and Combined Balance Sheets (Parenthetical) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Preferred shares, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred shares, shares authorized	200,000,000	200,000,000
Preferred shares, shares issued	0	0
Preferred shares, shares outstanding	0	0
Common shares, par value (in dollars per share)	$ 0.01	$ 0.01
Common shares, shares authorized	500,000,000	500,000,000
Common shares, shares issued	134,148,000	120,937,000
Common shares, shares outstanding	134,148,000	120,937,000
Commitments and Contingencies

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
REVENUE
Property rentals		$ 513,447	$ 451,541
Property rentals	$ 493,273
Third-party real estate services, including reimbursements	120,886	98,699	63,236
Other revenue	33,611	32,036	28,236
Total revenue	647,770	644,182	543,013
EXPENSES
Depreciation and amortization	191,580	211,436	161,659
Direct Costs of Leased and Rented Property or Equipment	137,622	148,081	118,836
Real estate taxes	70,493	71,054	66,434
General and administrative:
Corporate and other	46,822	33,728	39,350
Third-party real estate services	113,495	89,826	51,919
Share-based compensation related to Formation Transaction and special equity awards	42,162	36,030	29,251
Transaction and other costs	23,235	27,706	127,739
Total expenses	625,409	617,861	595,188
Income (loss) from unconsolidated real estate ventures, net	(1,395)	39,409	(4,143)
Interest and other income, net	5,385	15,168	1,788
Interest expense	(52,695)	(74,447)	(58,141)
Gain on sale of real estate	104,991	52,183	0
Loss on extinguishment of debt	(5,805)	(5,153)	(701)
Gain (reduction of gain) on bargain purchase	0	(7,606)	24,376
Total other income (expense)	50,481	19,554	(36,821)
INCOME (LOSS) BEFORE INCOME TAX BENEFIT	72,842	45,875	(88,996)
Income tax benefit	1,302	738	9,912
NET INCOME (LOSS)	74,144	46,613	(79,084)
Net (income) loss attributable to redeemable noncontrolling interests	(8,573)	(6,710)	7,328
Net loss attributable to noncontrolling interests	0	21	3
NET INCOME (LOSS) ATTRIBUTABLE TO COMMON SHAREHOLDERS	$ 65,571	$ 39,924	$ (71,753)
EARNINGS (LOSS) PER COMMON SHARE:
Earnings Per Share, Basic	$ 0.48	$ 0.31	$ (0.70)
Earnings Per Share, Diluted	$ 0.48	$ 0.31	$ (0.70)
Weighted average number of common shares outstanding — basic and diluted	130,687	119,176	105,359
Weighted Average Number of Shares Outstanding, Diluted	130,687	119,176	105,359

Consolidated and Combined State

Consolidated and Combined Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of Comprehensive Income [Abstract]
NET INCOME (LOSS)	$ 74,144	$ 46,613	$ (79,084)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, after Tax	(27,722)	5,382	1,438
Other Comprehensive Income (Loss) [Abstract]
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, after Tax	(1,694)	(1,090)	(399)
Other comprehensive income (loss)	26,028	(6,472)	(1,837)
COMPREHENSIVE INCOME (LOSS)	48,116	53,085	(77,247)
Net (income) loss attributable to redeemable noncontrolling interests	(8,573)	(6,710)	7,328
Other comprehensive (income) loss attributable to redeemable noncontrolling interests	2,584	(1,384)	(225)
Net loss attributable to noncontrolling interests	0	21	3
COMPREHENSIVE INCOME (LOSS) ATTRIBUTABLE TO JBG SMITH PROPERTIES	$ 42,127	$ 45,012	$ (70,141)

Consolidated Statements of Equi

Consolidated Statements of Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Shares	Additional Paid-In Capital	Accumulated Deficit	Accumulated Other Comprehensive Income	Noncontrolling Interests in Consolidated Subsidiaries	Former Parent Equity [Member]
Common Stock, Dividends, Per Share, Declared	$ 0.45
Balance at beginning of period at Dec. 31, 2016	$ 2,121,984					$ 295	$ 2,121,689
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to common shareholders and noncontrolling interests	(71,756)			$ (42,729)		(3)
Net income (loss)	(79,084)						(29,024)
Common shares issued		94,736
Conversion of common limited partnership units to common shares	0	$ (947)	$ (2,329,632)				(2,330,579)
Dividends	(53,080)			(53,080)
Distributions to noncontrolling interests	(171)					(171)
Contributions from noncontrolling interests	499					499
Redeemable noncontrolling interests redemption value adjustment and other comprehensive (income) loss allocation	(130,917)		(130,692)		$ (225)
Other Comprehensive Income (Loss), Net of Tax	1,837				1,837
Balance at end of period (in shares) at Dec. 31, 2017		117,955
Balance at end of period at Dec. 31, 2017	2,974,814	$ 1,180	3,063,625	(95,809)	1,612	4,206	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock Issued During Period, Value, Employee Benefit Plan	1,526						1,526
Stockholders' Equity Note, Spinoff Transaction	333,020					0	333,020
Stock Repurchased During Period, Value	96,632						96,632
Stock Issued During Period, Shares, Acquisitions		23,219
Issuance of common shares in connection with the Combination	864,918	$ 233	864,685
Noncontrolling Interest, Increase from Business Combination	$ 3,586					3,586
Common Stock, Dividends, Per Share, Declared	$ 1
Net income attributable to common shareholders and noncontrolling interests	$ 39,903			39,924		(21)
Conversion of common limited partnership units to common shares	2,962
Net income (loss)	$ 46,613						$ 0
Stock Issued During Period, Shares, Employee Stock Purchase Plans	20
Stock Issued During Period, Value, Employee Stock Purchase Plan	$ 741	0	741
Conversion of common limited partnership units to common shares	(109,122)	$ (30)	(109,092)
Dividends	(120,133)			(120,133)
Distributions to noncontrolling interests	(347)					(347)
Contributions from noncontrolling interests	250					250
Redeemable noncontrolling interests redemption value adjustment and other comprehensive (income) loss allocation	(17,556)		(16,172)		(1,384)
Other Comprehensive Income (Loss), Net of Tax	6,472				6,472
Other	$ (364)		(364)
Balance at end of period (in shares) at Dec. 31, 2018	120,937	120,937
Balance at end of period at Dec. 31, 2018	$ 2,987,352	$ 1,210	3,155,256	(176,018)	6,700	204
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common shares in connection with the Combination	0
Business Combination, Acquisition of Less than 100 Percent, Noncontrolling Interest, Fair Value	$ 5,550		1,666			3,884
Common Stock, Dividends, Per Share, Declared	$ 0.90
Net income attributable to common shareholders and noncontrolling interests	$ 65,571			65,571
Net income (loss)	74,144
Common shares issued		11,500
Conversion of common limited partnership units to common shares	$ 57,318	$ 17	57,301
Stock Issued During Period, Shares, Employee Stock Purchase Plans	47
Stock Issued During Period, Value, Employee Stock Purchase Plan	$ 1,803		1,803
Conversion of common limited partnership units to common shares	(472,780)	$ (115)	(472,665)
Conversion of common limited partnership units to common shares		1,664
Dividends	(120,717)			(120,717)
Distributions to noncontrolling interests	(176)					(176)
Contributions from noncontrolling interests	173					173
Redeemable noncontrolling interests redemption value adjustment and other comprehensive (income) loss allocation	(51,399)		(53,983)		2,584
Other Comprehensive Income (Loss), Net of Tax	$ (26,028)				(26,028)
Balance at end of period (in shares) at Dec. 31, 2019	134,148	134,148
Balance at end of period at Dec. 31, 2019	$ 3,386,677	$ 1,342	$ 3,633,042	$ (231,164)	$ (16,744)	$ 201
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common shares in connection with the Combination	$ 0

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
OPERATING ACTIVITIES:
Net income (loss)	$ 74,144,000	$ 46,613,000	$ (79,084,000)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Share-based compensation expense	65,273,000	52,675,000	33,693,000
Depreciation and amortization, including amortization of debt issuance costs	195,795,000	215,659,000	164,580,000
Deferred rent	(39,174,000)	(14,056,000)	(10,388,000)
(Income) loss from unconsolidated real estate ventures, net	1,395,000	(39,409,000)	4,143,000
Amortization of above- and below-market lease intangibles, net	(791,000)	(220,000)	(862,000)
Amortization of lease incentives	6,336,000	3,406,000	4,023,000
Gain (reduction of gain) on bargain purchase	0	(7,606,000)	24,376,000
Loss on extinguishment of debt	5,805,000	4,536,000	701,000
Gain on sale of real estate	(104,991,000)	(52,183,000)	0
Net unrealized loss (gain) on derivative financial instruments not designated as cash flow hedges	50,000	(926,000)	(1,348,000)
Losses on operating lease receivables	1,560,000	3,298,000	3,807,000
Return on capital from unconsolidated real estate ventures	2,690,000	7,827,000	2,563,000
Other non-cash items	517,000	1,388,000	3,955,000
Deferred tax benefit	(1,336,000)	(718,000)	(10,408,000)
Impairment of corporate assets	10,170,000	0	0
Changes in operating assets and liabilities:
Tenant and other receivables	(8,382,000)	(5,582,000)	(2,098,000)
Other assets, net	(9,177,000)	(16,600,000)	(23,481,000)
Accounts payable and accrued expenses	(7,678,000)	(5,984,000)	16,160,000
Other liabilities, net	(18,220,000)	(19,137,000)	(7,397,000)
Net cash provided by operating activities	173,986,000	188,193,000	74,183,000
INVESTING ACTIVITIES:
Development costs, construction in progress and real estate additions	(441,014,000)	(385,943,000)	(210,593,000)
Acquisition of real estate	165,208,000	23,246,000	0
Cash and restricted cash received in connection with the Combination, net			97,416,000
Deposits for real estate acquisitions	(850,000)	0	0
Proceeds from sale of real estate	377,511,000	413,077,000	0
Acquisition of interests in unconsolidated real estate ventures, net of cash acquired	0	(386,000)	(8,834,000)
Distributions of capital from unconsolidated real estate ventures	7,557,000	14,408,000	6,929,000
Distributions of capital from unconsolidated real estate ventures	0	80,279,000	0
Investments in and advances to unconsolidated real estate ventures	(18,668,000)	(31,197,000)	(16,321,000)
Repayment of notes receivable	0	0	50,934,000
Other	0	(665,000)	(2,207,000)
Proceeds from repayment of receivable from former parent	0	0	75,000,000
Net cash (used in) provided by investing activities	(240,672,000)	66,327,000	(7,676,000)
FINANCING ACTIVITIES:
Contributions from former parent, net	0	0	160,203,000
Acquisition of interest in consolidated real estate venture	0	(5,550,000)	0
Repayment of borrowings from former parent	0	0	(115,630,000)
Proceeds from borrowings from former parent	0	0	4,000,000
Finance lease payments	(137,000)	(114,000)	(17,827,000)
Borrowings under mortgages payable	2,200,000	118,141,000	366,239,000
Borrowings under revolving credit facility	200,000,000	35,000,000	115,751,000
Borrowings under unsecured term loans	0	250,000,000	50,000,000
Repayments of mortgages payable	(719,003,000)	(312,894,000)	(272,905,000)
Repayments of revolving credit facility	0	150,751,000	0
Debt issuance costs	515,000	3,114,000	19,287,000
Proceeds from the issuance of common stock, net of issuance costs	472,780,000	0	0
Proceeds from common stock issued pursuant to ESPP	1,457,000	597,000	0
Dividends paid to common shareholders	(129,834,000)	(107,372,000)	(26,540,000)
Distributions to redeemable noncontrolling interests	(17,390,000)	(17,398,000)	(4,556,000)
Contributions from noncontrolling interests	207,000	250,000	357,000
Distributions to noncontrolling interests	(95,000)	(340,000)	(18,000)
Net cash (used in) provided by in financing activities	(190,330,000)	(193,545,000)	239,787,000
Net (decrease) increase in cash and cash equivalents and restricted cash	(257,016,000)	60,975,000	306,294,000
Cash and cash equivalents and restricted cash as of the beginning of the period	399,532,000	338,557,000	32,263,000
Cash and cash equivalents and restricted cash as of the end of the period	142,516,000	399,532,000	338,557,000
CASH AND CASH EQUIVALENTS AND RESTRICTED CASH AS OF END OF THE PERIOD:
Cash and cash equivalents and restricted cash	399,532,000	399,532,000	32,263,000
SUPPLEMENTAL DISCLOSURE OF CASH FLOW AND NON-CASH INFORMATION:
Transfer of mortgage payable to former parent	0	0	115,630,000
Cash paid for interest (net of capitalized interest of $29,806, $20,804 and $12,727 in 2019, 2018 and 2017)	49,437,000	64,605,000	52,388,000
Accrued capital expenditures included in accounts payable and accrued expenses	84,076,000	53,073,000	12,445,000
Write-off of fully depreciated assets	66,533,000	52,272,000	55,998,000
Cash received (payments) for income taxes	282,000	(1,965,000)	3,396,000
Deconsolidation of properties	181,813,000	95,923,000	0
Acquisition of consolidated real estate venture	0	0	5,420,000
Fair value of OP Unit redemptions	(57,318,000)	(109,208,000)	0
Initial recognition of operating right-of-use assets	35,318,000	0	0
Initial recognition of lease liabilities related to operating right-of-use assets	37,922,000	0	0
Cash paid for amounts included in the measurement of lease liabilities for operating leases	6,202,000	0	0
Issuance of common limited partnership units at the Separation	0	0	96,632,000
Issuance of common shares at the Separation	0	0	2,330,579,000
Issuance of common shares in connection with the Combination	0	0	864,918,000
Issuance of common limited partnership units in connection with the Combination	0	0	359,967,000
Contribution from former parent in connection with the Separation	$ 0	$ 0	$ 172,817,000

Consolidated and Combined Sta_2

Consolidated and Combined Statements of Cash Flows (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of Cash Flows [Abstract]
Capitalized interest	$ 29,806	$ 20,804	$ 12,727

Organization and Basis of Prese

Organization and Basis of Presentation	12 Months Ended
	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Basis of Presentation	1. Organization and Basis of Presentation Organization JBG SMITH Properties ("JBG SMITH") was organized as a Maryland real estate investment trust ("REIT") for the purpose of receiving, via the spin-off on July 17, 2017 (the "Separation"), substantially all of the assets and liabilities of Vornado Realty Trust's Washington, D.C. segment (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." JBG SMITH is hereinafter referred to as "we," "us," "our" or other similar terms. References to "our share" refer to our ownership percentage of consolidated and unconsolidated assets in real estate ventures. Substantially all of our assets are held by, and our operations are conducted through, JBG SMITH Properties LP ("JBG SMITH LP"), our operating partnership. As of December 31, 2019 , we, as its sole general partner, controlled JBG SMITH LP and owned 89.9% of its common limited partnership units ("OP Units"). Prior to the Separation from Vornado Realty Trust ("Vornado" or "former parent"), 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 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. 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. The assets and liabilities of the JBG Assets, and subsequent results of operations and cash flows, are reflected in our consolidated and combined financial statements beginning on the date of the Combination. We own and operate a portfolio of high-growth commercial and multifamily assets, many of which are amenitized with ancillary retail. Our portfolio reflects our longstanding strategy of owning and operating assets within Metro-served submarkets in the Washington, D.C. metropolitan area that have high barriers to entry and key urban amenities, including being within walking distance of a Metro station. As of December 31, 2019 , our Operating Portfolio consists of 62 operating assets comprising 44 commercial assets totaling 12.7 million square feet ( 10.7 million square feet at our share) and 18 multifamily assets totaling 7,111 units ( 5,327 units at our share). Additionally, we have (i) seven assets under construction comprising four commercial assets totaling 943,000 square feet ( 821,000 square feet at our share) and three multifamily assets totaling 1,011 units ( 833 units at our share); and (ii) 40 future development assets totaling 21.9 million square feet ( 18.7 million square feet at our share) of estimated potential development density. Our revenues are derived primarily from leases with commercial and multifamily tenants, which include fixed rents and reimbursements from tenants for certain expenses such as real estate taxes, property operating expenses, and repairs and maintenance. In addition, our third-party asset management and real estate services business provides fee-based real estate services to third parties and the legacy funds (the "JBG Legacy Funds") formerly organized by JBG. Only the U.S. federal government accounted for 10% or more of our rental revenue, which consists of property rentals and other property revenue, as follows: Year Ended December 31, (Dollars in thousands) 2019 2018 2017 Rental revenue from the U.S. federal government $ 86,644 $ 94,822 $ 92,192 Percentage of commercial segment rental revenue 21.2 % 22.0 % 24.0 % Percentage of total rental revenue 16.7 % 17.6 % 19.4 % 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 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 7 for additional information on our VIEs. The portions of the equity and net income of consolidated subsidiaries that are not attributable to JBG SMITH are presented separately as amounts attributable to noncontrolling interests in our consolidated and combined financial statements. References to the financial statements refer to our consolidated and combined financial statements as of December 31, 2019 and 2018 , and for each of the three years in the period ended December 31, 2019 . References to our balance sheets refer to our consolidated balance sheets as of December 31, 2019 and 2018 . References to our statements of operations refer to our consolidated and combined statements of operations for each of the three years in the period ended December 31, 2019 . References to our statements of comprehensive income (loss) refer to our consolidated and combined statements of comprehensive income (loss) for each of the three years in the period ended December 31, 2019 . References to our statements 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, 2019 . Formation Transaction 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, 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 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 financial statements as of December 31, 2019 and 2018 and for the years ended December 31, 2019 and 2018 include our consolidated accounts. The results of operations for the year ended December 31, 2017 reflects the aggregate operations and changes in cash flows and equity on a combined basis for all periods prior to July 17, 2017 and on a consolidated basis for all periods subsequent to July 17, 2017. 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 for periods prior to the Formation Transaction reflect charges for certain corporate costs allocated by Vornado, which 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 20 for additional information. Reclassifications Certain prior period amounts have been reclassified to conform to the current period presentation as follows: • Reclassification of parking revenue totaling $25.7 million and $23.1 million previously included in "Property rentals revenue" for the years ended December 31, 2018 and 2017 to "Other revenue" in our statements of operations. • Reclassification of tenant reimbursements totaling $39.3 million and $38.0 million for the years ended December 31, 2018 and 2017

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2019
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 us to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the financial statements and the reported amounts of revenue and expenses during the reporting period. The most significant of these estimates include: (i) the underlying cash flows used in assessing impairment and (ii) the determination of useful lives for tangible and intangible assets. Actual results could differ from these estimates. Asset Acquisitions and Business Combinations We account for asset acquisitions, which includes the consolidation of previously unconsolidated real estate ventures, at cost, including transaction costs, plus the fair value of any assumed debt. 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 the date of acquisition. Based on these estimates, we allocate the purchase price, including all transaction costs related to the acquisition, to the identified assets acquired and liabilities assumed based on their relative fair value. We similarly account for business combinations by estimating the fair values of acquired tangible assets, identified intangible assets and liabilities, assumed debt and other liabilities, and noncontrolling interests, as applicable, based on our evaluation of information and estimates. Any excess of the purchase price over the estimated fair value of the net assets acquired is recorded as goodwill, and 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 assets acquired and liabilities assumed is received and the 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. Transaction costs are expensed as incurred and included in "Transaction and other costs" in our statements of operations. For both asset acquisitions and business combinations, the results of operations of acquisitions are prospectively included in our financial statements beginning with the date of the acquisition. The fair values of buildings are determined using the "as-if vacant" approach whereby we use discounted 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 lease) 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 lease intangible assets in "Other assets, net" in our balance sheets, and amounts allocated to below-market leases are recorded as lease intangible liabilities in "Other liabilities, net" in our balance sheets. These intangibles are amortized to "Property rentals revenue" 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 lease intangible assets in "Other assets, net" in our balance sheets and are amortized to "Depreciation and amortization expense" in our statements of operations over the remaining term of the existing lease; and • 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 expense" 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 is 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 the asset is ready for its intended use, but no later than one year from substantial completion of major construction activities. General and administrative costs are expensed as incurred. Depreciation and amortization require 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 and amortization are 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. When assets are sold or retired, their costs and related accumulated depreciation are removed from the accounts with the resulting gains or losses reflected in net income or loss for the period. 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 activities. Our assets and related intangible assets are 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. 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 proceeds from property dispositions held in escrow, 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. Investments in Real Estate Ventures We analyze our real estate ventures to determine whether the entities should be consolidated. If it is determined that these entities are VIEs in which we have a variable interest, we assess whether we are the primary beneficiary of the VIE to determine whether it should be consolidated. We are not the primary beneficiary of entities when we do not have voting control, lack the power to direct the activities that most significantly impact the entity's economic performance, or the limited partners (or non-managing members) have substantive participatory rights. If it is determined that these entities are not VIEs, then the determination as to whether we consolidate is based on whether we have a controlling financial interest in the entity, which is based on 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 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 have significant influence but do not have a controlling financial interest. Significant influence is typically indicated through ownership of 20% or more of the voting interests. Under the equity method, we record our investments in these entities in "Investments in unconsolidated real estate ventures" on 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 when earned. 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. 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 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 leases 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. Assets Held for Sale Assets, primarily consisting of real estate, are 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. 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. Noncontrolling Interests We identify our noncontrolling interests separately on our 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 our 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 became 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 our 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 12 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 designation . 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 (loss) 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 creditworthiness 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 our statements of operations or as a component of comprehensive income and as a component of shareholders’ equity on our 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 our statements of operations in the period in which the change occurs. Fair Value of Assets and Liabilities Accounting Standards Codification ("ASC") 820 ("Topic 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). Topic 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 We have leases with various tenants across our portfolio of properties, which generate rental income and operating cash flows for our benefit. Through these leases, we provide tenants with the right to control the use of our real estate, which tenants agree to use and control. The right to control our real estate conveys to our tenants substantially all of the economic benefits and the right to direct how and for what purpose the real estate is used throughout the period of use, thereby meeting the definition of a lease. Leases will be classified as either operating, sales-type or direct finance leases based on whether the lease is structured in effect as a financed purchase. Property rentals revenue includes base rent each tenant pays in accordance with the terms of its respective lease and is reported on a straight-line basis over the non-cancellable term of the lease, which includes the effects of periodic step-ups in rent and rent abatements under the lease. When a renewal option is included within the lease, we assess whether the option is reasonably certain of being exercised against relevant economic factors to determine whether the option period should be included as part of the lease term. Further, property rentals revenue includes tenant reimbursements revenue from the recovery of all or a portion of the operating expenses and real estate taxes of the respective assets. Tenant reimbursements, which vary each period, are non-lease components that are not the predominant activity within the contract. We combine certain lease and non-lease components of our operating leases. Non-lease components are recognized together with fixed base rent in "Property rentals revenue", as variable lease income in the same periods as the related expenses are incurred. Certain commercial leases may also provide for the payment by the lessee of additional rents based on a percentage of sales, which are recorded as variable lease income in the period the additional rents are earned. We commence rental revenue recognition when the tenant takes possession of the leased space or controls the physical use of the leased space and when the leased space is substantially ready for its intended use. In circumstances where we provide a tenant improvement allowance for improvements that are owned by the tenant, we recognize the allowance as a reduction of property rentals revenue on a straight-line basis over the term of the lease when the tenant takes possession of the space. Differences between rental revenue recognized and amounts due under the respective lease agreements are recorded as an increase or decrease to "Deferred rent receivable, net" on our balance sheets. Property rentals revenue also includes the amortization or accretion of acquired above-and below-market leases. We periodically evaluate the collectability of amounts due from tenants and recognize an adjustment to property rental revenue for the estimated losses resulting from the inability of tenants to make required payments under lease agreements. Any changes to the provision for lease revenue determined to be not probable of collection are included in "Property rentals revenue" in our statements of operations. We exercise judgment in assessing the probability of collection and consider payment history and current credit status in making this determination. Third-party real estate services revenue, including reimbursements, includes property and asset management fees, and transactional fees for leasing, acquisition, development and construction, financing, and legal services. These fees are determined in accordance with the terms specific to each arrangement and are recognized as the related services are performed. Development fees are earned from providing services to third-party property owners and our unconsolidated real estate ventures. The performance obligations associated with our development services contracts are satisfied over time and we recognize our development fee revenue using a time based measure of progress over the course of the development project due to the stand-ready nature of the promised services. The transaction prices for our performance obligations that are expected to be completed in greater than twelve months are variable based on the costs ultimately incurred to develop the underlying assets. Judgments impacting the timing and amount of revenue recognized from our development services contracts include the determination of the nature and number of performance obligations within a contract, estimates of total development project costs, from which the fees are typically derived, and estimates of the period of time over which the development services are expected to be performed, which is the period over which the revenue is recognized. We recognize development fees earned from unconsolidated joint venture projects to the extent of the third-party partners’ ownership interest. 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, including amounts paid to third-party contractors for construction management projects. 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. Lessee Accounting We are obligated under non-cancellable operating leases, including ground leases on certain of our properties through 2061. When a renewal option is included within a lease, we assess whether the option is reasonably certain of being exercised against relevant economic factors to determine whether the option period should be included as part of the lease term. Lease payments associated with renewal periods that we are reasonably certain will be exercised are included in the measurement of the corresponding lease liability and right-of-use asset. Lease expense for our operating leases is recognized on a straight-line basis over the expected lease term and is included in our statements of operations in either "Property operating expenses" or "General and administrative expense" depending on the nature of the lease. Certain lease agreements include variable lease payments that, in the future, will vary based on changes in inflationary measures, market rates or our share of expenditures of the leased premises. Such variable payments are recognized in lease expense in the period in which the variability is determined. Certain lease agreements may also include various non-lease components that primarily relate to property operating expenses associated with our office leases, which also vary each period. We have elected the practical expedient which allows us not to separate lease and non-lease components for our ground and office leases and recognize variable non-lease components in lease expense when incurred. We discount our future lease payments for each lease to calculate the related lease liability using an estimated incremental borrowing rate computed based on observable corporate borrowing rates reflective of the general economic environment, taking into consideration our creditworthiness and various financing and asset specific considerations, adjusted to approximate a secured borrowing for the lease term. We made a policy election to forgo recording right-of-use assets and the related lease liabilities for leases with initial terms of 12 months or less. Income Taxes We have elected to be taxed as a REIT under sections 856-860 of the Internal Revenue Code of 1986, as amended (the "Code"). Under those sections, a REIT which distributes at least 90% of its REIT taxable income as dividends to its shareholders each year and which meets certain other conditions will not be taxed on that portion of its taxable income which is distributed to its shareholders. Prior to the Separation, Vornado operated as a REIT and distributed 100% of its REIT 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 currently adhere and intend to continue to adhere to these requirements and to maintain our REIT status in future periods. As a REIT, we can reduce our taxable income by distributing all or a portion of such taxable income 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 and such other factors as our Board of Trustees deems relevant. We also participate in the activities conducted by our subsidiary entities that 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 our financial statements, which will result in taxable or deductible amounts in the future. We provide for a valuation allowance for deferred income tax assets if we believe all or some portion of the deferred tax asset may not be realized. Any increase or decrease in the valuation allowance that results from a change in circumstances that causes a change in the estimated ability to realize the related deferred tax asset is included in deferred tax benefit (expense). Accounting Standards Codification 740 ("Top

The Combination (Notes)

The Combination (Notes)	12 Months Ended
	Dec. 31, 2019
Business Combinations [Abstract]
Business Combination Disclosure [Text Block]	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 was based on the 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 unconsolidated real estate ventures 241,142 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) (48,127 ) Deferred tax liability (5) (18,610 ) Other liabilities acquired, net (60,048 ) Noncontrolling interests in consolidated subsidiaries (3,588 ) Net assets acquired 1,262,228 Gain on bargain purchase (6) 16,770 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 was paid in 2018, and a $34.1 million lease liability we assumed in relocating a tenant to one of our office buildings. The $34.1 million assumed lease liability was 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 of $24.4 million for the year ended December 31, 2017 because the fair value of the identifiable net assets acquired exceeded the purchase consideration. As a result of finalizing our fair value estimates used in the purchase price allocation related to the Combination, during the year ended December 31, 2018, we adjusted the fair value of certain assets acquired and liabilities assumed consisting of a decrease of $468,000 to investments in unconsolidated real estate ventures, an increase of $4.7 million to lease assumption liabilities and an increase of $2.4 million to other liabilities acquired, resulting in a reduction of the gain on bargain purchase of $7.6 million for the year ended December 31, 2018. The purchase consideration was based on the fair value of the common shares and OP Units issued in the Combination. We have concluded that all acquired assets and liabilities were recognized and that the valuation procedures and resulting estimates of fair values were appropriate. 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 (43,304 ) Portion of consideration attributable to performance of future services (3) (110,591 ) Fair value of common shares and OP Units purchase consideration $ 1,224,885 ____________________ (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 a 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 and special equity awards" in our statements of operations. The JBG Assets acquired on July 18, 2017 comprise: (i) 30 operating assets comprising 21 commercial assets totaling 4.1 million square feet ( 2.4 million square feet at our share) and nine multifamily assets with 2,883 units ( 1,099 units at our share); (ii) 11 commercial 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 commercial and multifamily assets totaling 401,000 square feet ( 242,000 square feet at our share); (iv) 26 future development assets totaling 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. Before the Combination, JBG/Operating Partners, L.P. was owned by 20 unrelated individuals, 19 of whom became our employees and three of whom serve on our Board of Trustees. The following is a summary of the fair values of tangible and identified intangible assets and liabilities, which have definite lives: 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. 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 .

Acquisition, Disposals and Asse

Acquisition, Disposals and Assets Held for Sale (Notes)	12 Months Ended
	Dec. 31, 2019
Discontinued Operations and Disposal Groups [Abstract]
Mergers, Acquisitions and Dispositions Disclosures [Text Block]	Acquisitions, Dispositions and Assets Held for Sale Acquisitions In December 2019, we acquired F1RST Residences, a 325 -unit multifamily asset in the Ballpark submarket of Washington, D.C. with approximately 21,000 square feet of street level retail, for $160.5 million through a like-kind exchange agreement with a third-party intermediary. See Note 7 for additional information. The multifamily portion of the building was 91.7% occupied as of December 31, 2019 . Transaction costs related to the asset acquisition of $4.7 million were included in the cost of the acquisition. During the year ended December 31, 2018, we purchased a land parcel and the remaining interest in the West Half real estate venture for an aggregate purchase price of $28.0 million . Dispositions The following is a summary of disposition activity for the year ended December 31, 2019 : Date Disposed Assets Segment Location Total Square Feet Gross Sales Price Cash Proceeds from Sale Gain on Sale of Real Estate (In thousands) February 4, 2019 Commerce Executive / Commerce Metro Land (1) (2) Commercial / Other Reston, Virginia 388,562 $ 114,950 $ 117,676 $ 39,033 July 31, 2019 1600 K Street Commercial Washington, D.C. 82,653 43,000 40,134 8,088 December 18, 2019 Vienna Retail Commercial Vienna, Virginia 8,584 7,400 7,005 4,514 479,799 $ 165,350 $ 164,815 51,635 December 12, 2019 Central Place Tower (3) Commercial Arlington, Virginia 53,356 Total $ 104,991 ______________ (1) The sale also included 894,000 square feet of estimated potential development density. The sale was part of a like-kind exchange. See Note 7 for additional information. (2) Cash proceeds include the reimbursement of $4.0 million of tenant improvement costs and leasing commissions paid by us prior to the closing. (3) Represents the gain, net of certain liabilities, on the sale of a 50.0% interest in the entity that owns Central Place Tower and the remeasurement of our remaining 50.0% interest to fair value. See Note 6 for additional information. During the year ended December 31, 2018, we sold four commercial assets, a future development asset and the out-of-service portion of a multifamily asset for an aggregate gross sales price of $427.4 million , resulting in gains on sale of real estate of $52.2 million . Assets Held for Sale As of December 31, 2019 and 2018 , we had certain real estate properties that were classified as held for sale. The amounts included in "Assets held for sale" in our balance sheets primarily represent the carrying value of real estate. The following is a summary of assets held for sale: Assets Segment Location Total Square Feet Assets Held for Sale Liabilities Related to Assets Held for Sale (In thousands) December 31, 2019 Pen Place (1) Other Arlington, Virginia — $ 73,895 $ — Metropolitan Park (1) Other Arlington, Virginia — 94,517 — — $ 168,412 $ — December 31, 2018 Commerce Executive / Commerce Metro Land (2) Commercial Reston, Virginia 388,562 $ 78,981 $ 3,717 _______________ (1) In March 2019, we entered into agreements for the sale of Pen Place and Metropolitan Park, land sites having an aggregate estimated potential development density of up to approximately 4.1 million square feet, for approximately $293.9 million , subject to customary closing conditions. In January 2020 , we sold the Metropolitan Park land sites to Amazon for the gross sales price of $155.0 million , which represents an $11.0 million increase over the previously estimated contract value as the result of an increase in the approved development density on the sites. The sale was part of a like-kind exchange. See Note 7 for additional information. (2) As noted above, we sold Commerce Executive/Commerce Metro Land in February 2019 .

Tenant and Other Receivables, N

Tenant and Other Receivables, Net (Notes)	12 Months Ended
	Dec. 31, 2019
Tenant and Other Receivables, Net [Abstract]
Tenant and Other Receivables Disclosure [Text Block]	Tenant and Other Receivables, Net The following is a summary of tenant and other receivables: December 31, 2019 2018 (In thousands) Tenants (1) $ 37,823 $ 31,362 Third-party real estate services 14,541 12,443 Other 577 9,463 Allowance for doubtful accounts (1) — (6,700 ) Total tenant and other receivables, net $ 52,941 $ 46,568 _______________ (1)

Investments in and Advances to

Investments in and Advances to Unconsolidated Real Estate Ventures	12 Months Ended
	Dec. 31, 2019
Equity Method Investments and Joint Ventures [Abstract]
Investments in and Advances to Unconsolidated Real Estate Ventures	Investments in Unconsolidated Real Estate Ventures The following is a summary of the composition of our investments in unconsolidated real estate ventures: Ownership Interest (1) December 31, Real Estate Venture Partners 2019 2018 (In thousands) Prudential Global Investment Management ("PGIM") 50.0% $ 215,624 $ — CPPIB 55.0% 109,911 97,521 Landmark 1.8% - 49.0% 77,944 84,320 CBREI Venture 5.0% - 64.0% 68,405 73,776 Berkshire Group 50.0% 46,391 43,937 Brandywine 30.0% 13,830 13,777 CIM Group ("CIM") and Pacific Life Insurance Company ("PacLife") 16.7% 10,385 9,339 Other 536 208 Total investments in unconsolidated real estate ventures $ 543,026 $ 322,878 _______________ (1) Ownership interests as of December 31, 2019 . We have multiple investments with certain venture partners with varying ownership interests. We provide leasing, property management and other real estate services to our unconsolidated real estate ventures. We recognized revenue, including expense reimbursements, of $28.5 million , $26.1 million and $12.9 million for each of the three years in the period ended December 31, 2019 for such services. PGIM In December 2019, we sold a 50.0% interest in a real estate venture that owns Central Place Tower, a 552,000 square foot office building located in Arlington, Virginia, to PGIM for the gross sales price of $220.0 million . Per the terms of the venture agreement, we determined the venture was not a VIE and we do not have a controlling financial interest in the venture. As a result, we deconsolidated our remaining 50.0% interest in the real estate venture and recorded a gain as our unconsolidated interest was increased to reflect its fair value. We recognized an aggregate $53.4 million gain, net of certain liabilities, recorded as "Gain on sale of real estate" in our statement of operations for the year ended December 31, 2019, on the partial sale and remeasurement of our remaining interest in the real estate venture subsequent to the transfer of control. CPPIB As of December 31, 2019 and 2018 , we had a zero investment balance in the real estate venture that owns 1101 17th Street and had suspended the equity method of accounting for the venture since June 30, 2018. We will recognize as income any future distributions from the venture until our share of unrecorded earnings and contributions exceeds the cumulative excess distributions previously recognized in income. During the years ended December 31, 2019 and 2018 , we recognized income of $6.4 million and $8.3 million related to distributions from this venture, which was included in "Income (loss) from unconsolidated real estate ventures, net" in our statement of operations. During the year ended December 31, 2018 , we also recognized the $5.4 million negative investment balance as income within "Income (loss) from unconsolidated real estate ventures, net" in our statement of operations as a result of the venture refinancing a mortgage payable collateralized by the property and eliminating certain principal guaranty provisions that had been included in a prior loan. In December 2018, our unconsolidated real estate venture with CPPIB sold The Warner, a 583,000 square foot office building located in Washington, D.C., for $376.5 million . In connection with the sale, the unconsolidated real estate venture recognized a gain on sale of $32.5 million , of which our proportionate share was $20.6 million , which was included in "Income (loss) from unconsolidated real estate ventures, net" in our statement of operations for the year ended December 31, 2018 . Additionally, in connection with the sale, our unconsolidated real estate venture repaid the related mortgage payable of $270.5 million . In February 2018, we entered into a real estate venture with CPPIB to develop and own 1900 N Street, an under construction commercial asset in Washington, D.C. We contributed 1900 N Street, valued at $95.9 million , to the real estate venture, and CPPIB committed to contribute approximately $101.3 million to the venture for a 45.0% interest, which reduced our ownership interest from 100.0% at the real estate venture's formation to 55.0% as CPPIB's contributions were funded. CIM and PacLife In January 2018, we invested $10.1 million for a 16.67% interest in a real estate venture with CIM and PacLife, which purchased the 1,152-key Wardman Park hotel, located adjacent to the Woodley Park Metro Station in northwest Washington, D.C. Prior to the acquisition by this venture, the JBG Legacy Funds owned a 47.64% interest in the Wardman Park hotel. The JBG Legacy Funds did not receive any proceeds from the sale, as the net proceeds were used to satisfy the prior mortgage debt. A third-party asset manager oversees the hotel operations on behalf of the venture and our involvement will increase only to the extent a land development opportunity becomes the primary business plan for the asset. JP Morgan In August 2018, JP Morgan, our former partner in the real estate venture that owned the Investment Building, a 401,000 square foot office building located in Washington, D.C., acquired our 5.0% interest in the venture for $24.6 million , resulting in a gain of $15.5 million , which was included in "Income (loss) from unconsolidated real estate ventures, net" in our statement of operations for the year ended December 31, 2018. The following is a summary of the debt of our unconsolidated real estate ventures: Weighted Average Effective (1) December 31, 2019 2018 (In thousands) Variable rate (2) 4.10% $ 629,479 $ 461,704 Fixed rate (3) 3.98% 561,236 665,662 Unconsolidated real estate ventures - mortgages payable 1,190,715 1,127,366 Unamortized deferred financing costs (2,859 ) (1,998 ) Unconsolidated real estate ventures - mortgages payable, net (4) $ 1,187,856 $ 1,125,368 ______________ (1) Weighted average effective interest rate as of December 31, 2019 . (2) Includes variable rate mortgages payable with interest rate cap agreements. (3) Includes variable rate mortgages payable with interest rates fixed by interest rate swap agreements. (4) See Note 19 for additional information on guarantees of the debt of certain of our unconsolidated real estate ventures. The following is a summary of the financial information for our unconsolidated real estate ventures: December 31, 2019 2018 Combined balance sheet information: (In thousands) Real estate, net $ 2,493,961 $ 2,050,985 Other assets, net (1) 291,092 169,264 Total assets $ 2,785,053 $ 2,220,249 Borrowings, net $ 1,187,856 $ 1,125,368 Other liabilities, net (1) 168,243 94,845 Total liabilities 1,356,099 1,220,213 Total equity 1,428,954 1,000,036 Total liabilities and equity $ 2,785,053 $ 2,220,249 ______________ (1) On January 1, 2019, our unconsolidated real estate ventures adopted Topic 842, which required the ventures to record operating right-of-use assets totaling $52.4 million and related lease liabilities totaling $44.1 million . Year Ended December 31, 2019 2018 2017 Combined income statement information: (In thousands) Total revenue $ 266,653 $ 300,032 $ 135,256 Operating income (1) 18,041 56,262 14,741 Net loss (32,507 ) (1,155 ) (7,593 ) ______________ (1) Includes gain on sale of The Warner of $32.5 million recognized by our unconsolidated real estate venture with CPPIB during the year ended December 31, 2018 .

Variable Interest Entities

Variable Interest Entities	12 Months Ended
	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Variable Interest Entities	Variable Interest Entities We hold various interests in entities deemed to be VIEs, which we evaluate at acquisition, formation, after a change in the ownership agreement or after a change in the real estate venture's economics to determine if the VIEs should be consolidated in our financial statements or should no longer be considered a VIE. Certain criteria we assess in determining whether the VIEs should be consolidated relate to our at-risk equity, our control over significant business activities, our voting rights, the noncontrolling interest kick-out rights and whether we are the primary beneficiary of the VIE. Unconsolidated VIEs As of December 31, 2019 and 2018 , we had interests in entities deemed to be VIEs that are in the development stage and do not hold sufficient equity at risk or conduct substantially all their operations on behalf of an investor with disproportionately few voting rights. Although we are engaged to act as the managing partner in charge of day-to-day operations of these investees, we are not the primary beneficiary of these VIEs as we do not hold unilateral power over activities that, when taken together, most significantly impact the respective VIE’s performance. We account for our investment in these entities under the equity method. As of December 31, 2019 and 2018 , the net carrying amounts of our investment in these entities were $242.9 million and $232.8 million , which are included in "Investments in unconsolidated real estate ventures" in our balance sheets. Our equity in the income of unconsolidated VIEs is included in "Income (loss) from unconsolidated real estate ventures, net" in our statements of operations. Our maximum loss exposure in these entities is limited to our investments, construction commitments and debt guarantees. See Note 19 for additional information. Consolidated VIEs JBG SMITH LP is our most significant consolidated VIE. We hold the majority limited partnership interest in the operating partnership, act as the general partner and exercise full responsibility, discretion and control over its day-to-day management. The noncontrolling interests of the operating partnership do not have substantive liquidation rights, substantive kick-out rights without cause, or substantive participating rights that could be exercised by a simple majority of noncontrolling interest limited partners (including by such a limited partner unilaterally). Because the noncontrolling interest holders do not have these rights, the operating partnership is a VIE. As general partner, we have the power to direct the core activities of the operating partnership that most significantly affect its performance, and through our majority interest in the operating partnership have both the right to receive benefits from and the obligation to absorb losses of the operating partnership. Accordingly, we are the primary beneficiary of the operating partnership and consolidate the operating partnership in our financial statements. As we conduct our business and hold our assets and liabilities through the operating partnership, the total assets and liabilities of the operating partnership comprise substantially all of our consolidated assets and liabilities. In conjunction with the acquisition of F1RST Residences, located in the Ballpark submarket of Washington, D.C. in December 2019, we entered into a like-kind exchange agreement with a third-party intermediary. As of December 31, 2019, the third-party intermediary was the legal owner of the entity that owned this property. The agreement that governed the operations of this entity provided us with the power to direct the activities that most significantly impacted the entity's economic performance. This entity was deemed a VIE as of December 31, 2019 primarily because it may not have had sufficient equity at risk to finance its activities without additional subordinated financial support from other parties. We determined we were the primary beneficiary of the VIE as a result of having had the power to direct the activities that most significantly impacted its economic performance and the obligation to absorb losses, as well as the right to receive benefits, that could have been potentially significant to the VIE. Accordingly, we consolidated the property and its operations as of the acquisition date. Legal ownership of this entity was transferred to us by the third-party intermediary as the like-kind exchange agreement was completed with the sale of the Metropolitan Park land sites in January 2020 . In conjunction with the acquisition of Potomac Yard Land Bay H, located in Alexandria, Virginia in December 2018, we entered into a like-kind exchange agreement with a third-party intermediary. As of December 31, 2018, the third-party intermediary was the legal owner of the entity that owned this property. The agreement that governed the operations of this entity provided us with the power to direct the activities that most significantly impacted the entity's economic performance. This entity was deemed a VIE as of December 31, 2018 primarily because it may not have had sufficient equity at risk to finance its activities without additional subordinated financial support from other parties. We determined we were the primary beneficiary of the VIE as a result of having had the power to direct the activities that most significantly impacted its economic performance and the obligation to absorb losses, as well as the right to receive benefits, that could have been potentially significant to the VIE. Accordingly, we consolidated the property and its operations as of the acquisition date. Legal ownership of this entity was transferred to us by the third-party intermediary as the like-kind exchange agreement was completed with the sale of Commerce Executive/Commerce Metro Land in February 2019 . We consolidate VIEs in which we control the most significant business activities. These entities are VIEs because they are in the development stage and do not hold sufficient equity at risk. We are the primary beneficiaries of these VIEs because the noncontrolling interest holders do not have substantive kick-out or participating rights, and we control all of the significant business activities. As of December 31, 2019 , excluding the operating partnership, we consolidated two VIEs with total assets and liabilities of $136.8 million and $11.8 million . As of December 31, 2018 , excluding the operating partnership, we consolidated two VIEs with total assets and liabilities of $94.8 million and $43.4 million

Other Assets, Net

Other Assets, Net	12 Months Ended
	Dec. 31, 2019
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Other Assets, Net	Other Assets, Net The following is a summary of other assets, net: December 31, 2019 2018 (In thousands) Deferred leasing costs $ 205,830 $ 202,066 Accumulated amortization (79,814 ) (72,465 ) Deferred leasing costs, net $ 126,016 $ 129,601 Lease intangible assets, net 23,644 34,390 Other identified intangible assets, net 48,620 55,469 Operating right-of-use assets, net (1) 19,865 — Prepaid expenses 12,556 6,482 Deferred financing costs on credit facility, net 3,071 4,806 Deposits 3,210 3,633 Derivative agreements, at fair value — 10,383 Other 16,705 20,230 Total other assets, net $ 253,687 $ 264,994 ______________ (1) Related to our adoption of Topic 842 on January 1, 2019. See Note 2 for additional information. The following is a summary of the composition of lease intangible assets, net: December 31, 2019 2018 (in thousands) Lease intangible assets: In-place leases $ 33,812 $ 38,216 Above-market real estate leases 8,635 9,414 Below-market ground leases — 2,215 Total lease intangibles assets 42,447 49,845 Accumulated amortization: In-place leases 15,231 11,602 Above-market real estate leases 3,572 2,405 Below-market ground leases — 1,448 Total accumulated amortization 18,803 15,455 Lease intangible assets, net $ 23,644 $ 34,390 The following is a summary of the composition of other identified intangible assets, net: December 31, 2019 2018 (in thousands) Other identified intangible assets: Option to enter into ground lease $ 17,090 $ 17,090 Management and leasing contracts 48,900 48,900 Other 166 166 Total other identified intangibles assets 66,156 66,156 Accumulated amortization: Management and leasing contracts 17,385 10,297 Other 151 390 Total accumulated amortization 17,536 10,687 Other identified intangible assets, net $ 48,620 $ 55,469 The following is a summary of amortization expense related to lease and other identified intangible assets: Year Ended December 31, 2019 2018 2017 (in thousands) In-place lease amortization (1) $ 7,375 $ 11,807 $ 10,216 Above-market real estate lease amortization (2) 1,730 2,390 1,428 Below-market ground lease amortization (3) — 85 87 Management and leasing contract amortization (1) 7,088 7,088 3,209 Other amortization (240 ) 191 14 Total lease and other identified intangible asset amortization expense $ 15,953 $ 21,561 $ 14,954 ___________________________________________ (1) Amounts are included in "Depreciation and amortization expense" 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. The following is a summary of the estimated amortization of lease and other identified intangible assets for the next five years and thereafter as of December 31, 2019 : Year ending December 31, Amount (in thousands) 2020 $ 12,949 2021 9,993 2022 8,999 2023 8,510 2024 7,973 Thereafter 6,750 Total (1) $ 55,174 ___________________________________________ (1) Estimated amortization related to the option to enter into ground lease is not included within the amortization table above as the ground lease does not have a definite start date.

Debt

Debt	12 Months Ended
	Dec. 31, 2019
Debt Disclosure [Abstract]
Debt	Debt Mortgages Payable The following is a summary of mortgages payable: Weighted Average (1) December 31, 2019 2018 (In thousands) Variable rate (2) 3.36% $ 2,200 $ 308,918 Fixed rate (3) 4.29% 1,125,648 1,535,734 Mortgages payable 1,127,848 1,844,652 Unamortized deferred financing costs and premium/ discount, net (2,071 ) (6,271 ) Mortgages payable, net $ 1,125,777 $ 1,838,381 __________________________ (1) Weighted average effective interest rate as of December 31, 2019 . (2) Includes a variable rate mortgage payable with an interest rate cap agreement as of December 31, 2018 . (3) Includes variable rate mortgages payable with interest rates fixed by interest rate swap agreements. As of December 31, 2019 and 2018 , the net carrying value of real estate collateralizing our mortgages payable, excluding assets held for sale, totaled $1.4 billion and $2.3 billion . Our mortgages payable 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 mortgages payable are recourse to us. See Note 19 for additional information. As of December 31, 2019 , we were not in default under any mortgage loan. During the year ended December 31, 2019 , aggregate borrowings under mortgages payable totaled $2.2 million related to construction draws. During the year ended December 31, 2019 , we repaid mortgages payable with an aggregate principal balance of $709.1 million . The loss on the extinguishment of debt was $5.8 million for the year ended December 31, 2019 , of which $2.9 million related to our repayment of various mortgages payable and $2.9 million related to the termination of various interest rate swaps in connection with the repayment of the loan encumbering Central Place Tower. In February 2020, we entered into a mortgage loan with a principal balance of $175.0 million collateralized by 4747 and 4749 Bethesda Avenue. During the year ended December 31, 2018 , aggregate borrowings totaled $118.1 million , of which $47.5 million related to the principal balance on a new mortgage payable collateralized by 1730 M Street and the remainder related to construction draws under mortgages payable. During the year ended December 31, 2018 , we repaid mortgages payable with an aggregate principal balance of $298.1 million , which resulted in a loss on the extinguishment of debt of $5.2 million . As of December 31, 2019 and 2018 , we had various interest rate swap and cap agreements on certain of our mortgages payable with an aggregate notional value of $867.6 million and $1.3 billion . During the year ended December 31, 2019 , in connection with the repayment of the loan encumbering Central Place Tower, we terminated various interest rate swaps with an aggregate notional value of $220.0 million . During the year ended December 31, 2018 , we entered into various interest rate swap and cap agreements on certain of our mortgages payable with an aggregate notional value of $381.3 million . See Note 17 for additional information. Credit Facility As of December 31, 2019 , our $1.4 billion credit facility consisted 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 . Effective as of July 17, 2019, the credit facility was amended to extend the delayed draw period of our Tranche A-1 Term Loan to July 2020. In December 2019, we drew $200.0 million under the revolving credit facility, which was repaid in 2020. Based on the terms as of December 31, 2019 , 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, effective as of July 17, 2019, from LIBOR plus 1.15% to LIBOR plus 1.70% , reflecting a 40 basis points reduction from the prior credit facility. There are various LIBOR options in the credit facility, and we elected the one-month LIBOR option as of December 31, 2019 . We were not in default under our credit facility as of December 31, 2019 . In January 2020, the credit facility was amended to extend the maturity date of the revolving credit facility from July 2021 to January 2025, and to reduce its range of interest rates by five basis points to LIBOR plus 1.05% to 1.50% . As of December 31, 2019 and 2018 , we had interest rate swaps with an aggregate notional value of $100.0 million , which mature in January 2023 and effectively convert the variable interest rate applicable to our Tranche A-1 Term Loan to a fixed interest rate, providing weighted average base interest rates under the facility agreements of 2.12% per annum for both periods. As of December 31, 2019 , we had interest rate swaps with an aggregate notional value of $137.6 million , which effectively convert the variable interest rate applicable to a portion of the outstanding balance of our Tranche A-2 Term Loan to a fixed interest rate, providing a weighted average base interest rate under the facility agreements of 2.59% per annum. The following is a summary of amounts outstanding under the credit facility: Effective December 31, Interest Rate (1) 2019 2018 (In thousands) Revolving credit facility (2) (3) (4) 2.86% $ 200,000 $ — Tranche A-1 Term Loan (5) 3.32% $ 100,000 $ 100,000 Tranche A-2 Term Loan (5) 3.74% 200,000 200,000 Unsecured term loans 300,000 300,000 Unamortized deferred financing costs, net (2,705 ) (2,871 ) Unsecured term loans, net $ 297,295 $ 297,129 __________________________ (1) Interest rate as of December 31, 2019 . (2) As of December 31, 2019 and 2018 , letters of credit with an aggregate face amount of $1.5 million and $5.7 million were provided under our revolving credit facility. (3) As of December 31, 2019 and 2018 , net deferred financing costs related to our revolving credit facility totaling $3.1 million and $4.8 million were included in "Other assets, net." (4) The interest rate for the revolving credit facility excludes a 0.15% facility fee. In January 2020, the credit facility was amended to extend the maturity date of the revolving credit facility from July 2021 to January 2025, and to reduce its range of interest rates by five basis points to LIBOR plus 1.05% to 1.50% . (5) The interest rate includes the impact of interest rate swap agreements.

Other Liabilities, Net

Other Liabilities, Net	12 Months Ended
	Dec. 31, 2019
Other Liabilities Disclosure [Abstract]
Other Liabilities, Net	Other Liabilities, Net The following is a summary of other liabilities, net: December 31, 2019 2018 (In thousands) Lease intangible liabilities $ 38,577 $ 40,179 Accumulated amortization (26,253 ) (26,081 ) Lease intangible liabilities, net $ 12,324 $ 14,098 Prepaid rent 23,612 21,998 Lease assumption liabilities 17,589 23,105 Lease incentive liabilities 20,854 9,317 Lease liabilities related to operating right-of-use assets (1) 28,476 — Finance lease liability (2) — 15,704 Security deposits 16,348 17,696 Environmental liabilities 17,898 17,898 Ground lease deferred rent payable (3) — 3,510 Net deferred tax liability 5,542 6,878 Dividends payable 34,012 45,193 Derivative agreements, at fair value 17,440 1,723 Other 11,947 4,486 Total other liabilities, net $ 206,042 $ 181,606 __________________________ (1) Related to our adoption of Topic 842 on January 1, 2019. See Note 2 for additional information. (2) In December 2019, we sold a 50.0% interest in Central Place Tower, which resulted in the deconsolidation of the entity that was the lessee to our sole finance lease. See Note 6 for additional information. (3) In connection with our adoption of Topic 842 on January 1, 2019, the ground lease deferred rent payable balance as of December 31, 2018 was included in the initial determination of the operating right-of-use assets. See Note 2 for additional information. Amortization expense included in "Property rentals revenue" in our statements of operations related to lease intangible liabilities for each of the three years in the period ended December 31, 2019 was $2.5 million , $2.6 million and $2.3 million . The following is a summary of the estimated amortization of lease intangible liabilities for the next five years and thereafter as of December 31, 2019 ,: Year ending December 31, Amount (in thousands) 2020 $ 2,017 2021 1,800 2022 1,781 2023 1,773 2024 1,755 Thereafter 3,198 Total $ 12,324

Income Taxes (Notes)

Income Taxes (Notes)	12 Months Ended
	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Income Tax Disclosure [Text Block]	Income Taxes We have elected to be taxed as a REIT, and accordingly, we have incurred no federal income tax expense related to our REIT subsidiaries except for 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 recorded tax charges in 2017 for the impact of the 2017 Tax Act were made using the current available information and technical guidance on the interpretations of the 2017 Tax Act. As permitted by Securities and Exchange Commission Staff Accounting Bulletin 118, Income Tax Accounting Implications of the Tax Cuts and Jobs Act, we subsequently finalized our accounting analysis based on the guidance, interpretations and data available as of December 31, 2018. We did not have any changes to our 2017 estimate related to the 2017 Tax Act and therefore, it had no impact to our 2018 financial statements. 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, 2019 , our TRSs have an estimated federal and state net operating loss of $3.6 million , which will expire in 2038 and 2039 . The net basis of our assets and liabilities for tax reporting purposes is approximately $55.9 million higher than the amounts reported in our balance sheet as of December 31, 2019 . The following is a summary of our income tax benefit: Year Ended December 31, 2019 2018 2017 (in thousands) Current tax benefit (expense) $ (34 ) $ 20 $ (496 ) Deferred tax benefit 1,336 718 10,408 Income tax benefit $ 1,302 $ 738 $ 9,912 As of December 31, 2019 and 2018 , we have a net deferred tax liability of $5.5 million and $6.9 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 remaining from 2018 and 2017. We are subject to federal, state and local income tax examinations by taxing authorities for 2016 through 2019. December 31, 2019 2018 (in thousands) Deferred tax assets: Accrued bonus $ 721 $ — Net operating loss 915 2,326 Deferred revenue 626 998 Bad debt expense — 583 Charitable contributions 435 — Other 217 198 Total deferred tax assets 2,914 4,105 Valuation allowance (523 ) (469 ) Total deferred tax assets, net of valuation allowance 2,391 3,636 Deferred tax liabilities: Management and leasing contracts (7,412 ) (9,905 ) Other (521 ) (609 ) Total deferred tax liabilities (7,933 ) (10,514 ) Net deferred tax liability $ (5,542 ) $ (6,878 ) During the year ended December 31, 2019 , our Board of Trustees declared cash dividends totaling $0.90 of which $0.333 was taxable as ordinary income for federal income tax purposes, $0.342 were capital gain distributions and the remaining $0.225 will be determined in 2020. During the year ended December 31, 2018 , our Board of Trustees declared cash dividends totaling $1.00 (regular dividends of $0.90 per common share and a special dividend of $0.10 per common share) of which $0.531 was taxable as ordinary income for federal income tax purposes and $0.469 were capital gain distributions. During the year ended December 31, 2017 , our Board of Trustees declared cash dividends of $0.45 per common share of which $0.385 was taxable as ordinary income for federal income tax purposes and $0.065 were capital gains distributions.

Redeemable Noncontrolling Inter

Redeemable Noncontrolling Interests	12 Months Ended
	Dec. 31, 2019
Noncontrolling Interest [Abstract]
Redeemable Noncontrolling Interests	Redeemable Noncontrolling Interests JBG SMITH LP A portion of the OP Units held by persons other than JBG SMITH became redeemable for cash or, at our election, our common shares beginning on August 1, 2018, subject to certain limitations. During the years ended December 31, 2019 and 2018 , unitholders redeemed 1.7 million and 3.0 million OP Units, which we elected to redeem for an equivalent number of our common shares. As of December 31, 2019 , outstanding OP Units totaled 15.2 million , representing a 10.1% ownership interest in JBG SMITH LP. On our balance sheets, our OP Units and certain vested LTIPs are presented at the higher of their redemption value or their carrying value, with such adjustments recognized in "Additional paid-in capital." Redemption value per OP Unit is equivalent to the market value of one of our common shares at the end of the period. In 2020, as of the date of this filing, unitholders redeemed 733,851 OP Units, which we elected to redeem for an equivalent number of our common shares. Consolidated Real Estate Venture We are a partner in a real estate venture that owns an under construction multifamily asset located at 965 Florida Avenue in Washington, D.C. Pursuant to the terms of the real estate venture agreement, we will fund all capital contributions until our ownership interest reaches a maximum of 97.0% . Our partner can redeem its interest, for cash, two years after delivery, but no later than seven years after delivery. As of December 31, 2019 , we held a 95.0% ownership interest in the real estate venture. The following is a summary of the activity of redeemable noncontrolling interests: Year Ended December 31, 2019 2018 JBG SMITH LP Consolidated Real Estate Venture Total JBG SMITH LP Consolidated Real Estate Venture Total (In thousands) Balance as of beginning of period $ 552,159 $ 5,981 $ 558,140 $ 603,717 $ 5,412 $ 609,129 OP Unit redemptions (57,318 ) — (57,318 ) (109,208 ) — (109,208 ) LTIP Units issued in lieu of cash bonuses (1) 3,954 — 3,954 — — — Net income attributable to redeemable noncontrolling interests 8,566 7 8,573 6,641 69 6,710 Other comprehensive income (loss) (2,584 ) — (2,584 ) 1,384 — 1,384 Contributions (distributions) (15,325 ) 71 (15,254 ) (18,737 ) 500 (18,237 ) Share-based compensation expense 63,264 — 63,264 52,190 — 52,190 Adjustment to redemption value 53,983 — 53,983 16,172 — 16,172 Balance as of end of period $ 606,699 $ 6,059 $ 612,758 $ 552,159 $ 5,981 $ 558,140

Share-Based Payments and Employ

Share-Based Payments and Employee Benefits	12 Months Ended
	Dec. 31, 2019
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-Based Payments and Employee Benefits	Share-Based Payments and Employee Benefits OP UNITS The acquisition of JBG/Operating Partners, L.P. in the Combination, resulted in the issuance of 3.3 million OP Units to the former owners with an estimated grant-date fair value of $110.6 million . The OP Units are subject to post-combination vesting over periods of either 12 or 60 months based on continued employment. The significant assumptions used to value the OP Units included expected volatility ( 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 is a summary of the OP Units activity: Unvested Shares Weighted Average Grant-Date Fair Value Unvested at December 31, 2018 2,999,987 $ 33.39 Vested (127,735 ) 33.39 Unvested at December 31, 2019 2,872,252 33.39 The total-grant date fair value of the OP Units that vested for each of the three years in the period ended December 31, 2019 was $4.3 million , $3.2 million and $7.2 million . 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 10.3 million of our common shares pursuant to the Plan. As of December 31, 2019 , there were 3.9 million common shares available for issuance under the Plan. Formation Awards Pursuant to the Plan, on July 18, 2017, we granted 2.7 million formation awards ("Formation Awards") based on an aggregate notional value of approximately $100 million divided by the volume-weighted average price on July 18, 2017 of $37.10 per common share. In 2018, we granted 93,784 Formation Awards based on an aggregate notional value of $3.2 million divided by the volume-weighted average price on the date of issuance of $34.40 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 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 date granted, 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 the volume-weighted average price of a common share at the time the Formation Award was granted 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. 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 aggregate grant-date fair value of the Formation Awards granted during the years ended December 31, 2018 and 2017 was $725,000 and $23.7 million estimated using Monte Carlo simulations. No Formation Awards were granted during the year ended December 31, 2019. Compensation expense for these awards is being recognized over a five -year period. The following is a summary of the significant assumptions used to value the Formation Awards: Year Ended December 31, 2018 2017 Expected volatility 27.0% to 29.0% 26.0 % Dividend yield 2.5% to 2.7% 2.3 % Risk-free interest rate 2.8% to 3.0% 2.3 % Expected life 7 years 7 years The following is a summary of the Formation Awards activity: Unvested Shares Weighted Average Grant-Date Fair Value Unvested at December 31, 2018 2,655,394 $ 8.81 Vested (160,746 ) 8.84 Forfeited (9,702 ) 8.55 Unvested at December 31, 2019 2,484,946 8.81 The total-grant date fair value of the Formation Awards that vested during the years ended December 31, 2019 and 2018 was $1.4 million and $333,000 . LTIP, Time-Based LTIP and Special Time-Based LTIP Units During the years ended December 31, 2019 and 2018 , as part of their annual compensation, we granted a total of 50,159 and 25,770 fully vested LTIP Units to non-employee trustees with an aggregate grant-date fair value of $1.8 million and $794,000 . The LTIP Units may not be sold while such non-employee trustee is serving on the Board. On July 18, 2017, we granted a total of 47,166 fully vested LTIP Units to the seven independent trustees in the notional amount of $250,000 each. 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. During each of the three years in the period ended December 31, 2019 , we granted 351,982 , 367,519 and 302,518 Time-Based LTIP Units to management and other employees with a weighted average grant-date fair value of $34.26 , $31.48 and $33.71 per unit that vest over four years , 25.0% per year, subject to continued employment. Compensation expense for these units is being recognized over a four -year period. During the year ended December 31, 2019 , we granted 91,636 of fully vested LTIP Units, with a grant-date fair value of $34.21 per unit, to certain executives who elected to receive all or a portion of their cash bonus paid in 2019, related to 2018 service, as LTIP Units. Additionally, during the year ended December 31, 2018 , related to our successful pursuit of Amazon's additional headquarters in National Landing, we granted 356,591 Special Time-Based LTIP Units to management and other employees with a weighted average grant-date fair value of $36.84 per unit. The Special Time-Based LTIP Units vest 50% on each of the fourth and fifth anniversaries of the grant date, subject to continued employment. Compensation expense for these units is being recognized over a five -year period. The aggregate grant-date fair value of the LTIP, Time-Based LTIP and Special Time-Based LTIP Units granted (collectively "Granted LTIPs") for each of the three years in the period ended December 31, 2019 was $17.0 million , $25.5 million and $13.7 million , valued using Monte Carlo simulations. Holders of the Granted LTIPs have the right to convert all or a portion of vested units into OP Units, which are then subsequently exchangeable for our common shares. Granted LTIPs do not have redemption rights, but any OP Units into which units are converted are entitled to redemption rights. Granted LTIPs, 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 Granted LTIPs. The following is a summary of the significant assumptions used to value the Granted LTIPs: Year Ended December 31, 2019 2018 2017 Expected volatility 18.0% to 24.0% 20.0% to 22.0% 17.0% to 19.0% Risk-free interest rate 2.3% to 2.6% 1.9% to 2.6% 1.3% to 1.5% Post-grant restriction periods 2 to 3 years 2 to 3 years 2 to 3 years The following is a summary of the Granted LTIP activity: Unvested Shares Weighted Average Grant-Date Fair Value Unvested at December 31, 2018 962,662 $ 34.03 Granted 493,777 34.40 Vested (360,703 ) 33.15 Forfeited (393 ) 34.52 Unvested at December 31, 2019 1,095,343 34.35 The total-grant date fair value of the Granted LTIPs that vested for each of the three years in the period ended December 31, 2019 was $12.0 million , $3.6 million and $2.5 million . In 2020, we issued 471,598 LTIP Units to management and employees with an estimated aggregate grant-date fair value of $18.3 million . Performance-Based LTIP and Special Performance-Based LTIP Units During each of the three years in the period ended December 31, 2019 , we granted 478,411 , 567,106 and 605,072 Performance-Based LTIP Units to management and other employees. During the year ended December 31, 2018, related to our successful pursuit of Amazon's additional headquarters at our properties in National Landing, we granted 511,555 Special Performance-Based LTIP Units to management and other employees. Performance-Based LTIP Units, including the Special Performance-Based LTIP Units, are performance-based equity compensation pursuant to which participants have the opportunity to earn 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 defined performance period beginning on the grant date, inclusive of dividends and stock price appreciation. Our Performance-Based LTIP and Special Performance-Based LTIP Units have a three -year performance period. Fifty percent of any Performance-Based LTIP Units that are earned vest at the end of the three -year performance period and the remaining 50% on the fourth anniversary of the date of grant, subject to continued employment. Fifty percent of any Special Performance-Based LTIP Units that are earned at the end of the three -year performance period vest on the fourth anniversary of the date of grant and the remaining 50% on the fifth anniversary of the date of grant, subject to continued employment. The aggregate grant-date fair value of the Performance-Based LTIP and Special Performance-Based LTIP Units granted for each of the three years in the period ended December 31, 2019 was $9.3 million , $21.1 million and $9.7 million , valued using Monte Carlo simulations. Compensation expense for the Performance-Based LTIP Units is being recognized over a four -year period, while compensation expense for the Special Performance Based LTIP Units is being recognized over a five -year period. The following is a summary of the significant assumptions used to value both the Performance-Based LTIP and Special Performance-Based LTIP Units: Year Ended December 31, 2019 2018 2017 Expected volatility 19.0% to 23.0% 19.9% to 26.0% 18.0 % Dividend yield 2.3% to 2.5% 2.5% to 2.7% 2.3 % Risk-free interest rate 2.3% to 2.6% 2.3% to 3.0% 1.5 % The following is a summary of both the Performance-Based LTIP and Special Performance-Based LTIP Units activity: Unvested Shares Weighted Average Grant-Date Fair Value Unvested at December 31, 2018 1,657,578 $ 18.27 Granted 478,411 19.49 Forfeited (18,054 ) 18.00 Unvested at December 31, 2019 2,117,935 18.55 In 2020, we issued 593,100 Performance-Based LTIP Units to management and employees with an estimated aggregate grant-date fair value of $11.1 million . JBG SMITH 2017 ESPP The JBG SMITH 2017 ESPP authorized the issuance of up to 2.1 million common shares. The ESPP provides eligible employees an option to purchase, through payroll deductions, our common shares at a discount of 15.0% of the closing price of a common share on relevant determination dates, provided that the fair market value of common shares, determined as of the first day of the relevant offering period, purchased by any eligible employee may not exceed $25,000 in any calendar year. The maximum aggregate number of common shares reserved for issuance under the ESPP will automatically increase on January 1 of each year, unless the Compensation Committee of the Board of Trustees determines to limit any such increase, by the lesser of (i) 0.10% of the total number of outstanding common shares on December 31 of the preceding calendar year or (ii) 206,600 common shares. Pursuant to the ESPP, employees purchased 47,022 and 20,178 common shares for $1.5 million and $597,000 during the years ended December 31, 2019 and 2018 . The following is a summary of the significant assumptions used to value the ESPP common shares using the Black-Scholes model: Year Ended December 31, 2019 2018 Expected volatility 18.0% to 28.0% 21.0 % Dividend yield 2.6% to 3.5% 2.5 % Risk-free interest rate 2.2% to 2.4% 2.0 % Expected life 6 months 6 months As of December 31, 2019 , there were 2.0 million common shares available for issuance under the ESPP. Share-Based Compensation Expense The following is a summary of share-based compensation expense: Year Ended December 31, 2019 2018 2017 (In thousands) Time-Based LTIP Units $ 11,386 $ 10,095 $ 2,211 Performance-Based LTIP Units 8,716 5,271 1,172 LTIP Units 1,000 794 — Other equity awards (1) 4,535 3,826 1,526 Share-based compensation expense - other 25,637 19,986 4,909 Formation Awards 5,734 5,606 5,169 OP Units (2) 29,826 29,455 21,467 LTIP Units (2) 456 277 2,615 Special Performance-Based LTIP Units (3) 2,843 323 — Special Time-Based LTIP Units (3) 3,303 369 — Share-based compensation related to Formation Transaction and special equity awards (4) 42,162 36,030 29,251 Total share-based compensation expense 67,799 56,016 34,160 Less amount capitalized (2,526 ) (3,341 ) (467 ) Share-based compensation expense $ 65,273 $ 52,675 $ 33,693 ______________________________________________ (1) For the years ended December 31, 2019 and 2018 , primarily includes compensation expense for certain executives who have elected to receive all or a portion of any cash bonus that may be paid in the subsequent year related to past service in the form of fully vested LTIP Units and related to our ESPP. For the year ended December 31, 2017, represents share-based compensation expense related to equity awards prior to the Formation Transaction. (2) Represents share-based compensation expense for LTIP Units and OP Units subject to post-Combination employment obligations. (3) Represents equity awards issued related to our successful pursuit of Amazon's additional headquarters in National Landing. (4) Included in "General and administrative expense: Share-based compensation related to Formation Transaction and special equity awards" in the accompanying statements of operations. As of December 31, 2019 , we had $77.4 million of total unrecognized compensation expense related to unvested share-based payment arrangements, which is expected to be recognized over a weighted average period of 2.2 years. Employee Benefits We have a 401(k) defined contribution 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 after one year. Our contributions for each of the three years in the period ended December 31, 2019 were $2.0 million , $1.8 million and $3.6 million .

Transaction and Other Costs Tra

Transaction and Other Costs Transaction and Other Costs	12 Months Ended
	Dec. 31, 2019
Other Income and Expenses [Abstract]
Schedule of Other Operating Cost and Expense, by Component [Table Text Block]	Transaction and Other Costs The following is a summary of transaction and other costs: Year Ended December 31, 2019 2018 2017 (In thousands) Relocation of corporate headquarters (1) $ 10,900 $ — $ — Demolition costs (2) 5,432 — — Formation transaction and integration costs (3) 5,252 15,907 127,739 Completed, potential and pursued transaction expenses 651 9,008 — Other (4) 1,000 2,791 — Transaction and other costs $ 23,235 $ 27,706 $ 127,739 __________________________ (1) In November 2019, we relocated our corporate headquarters. Upon the relocation of our corporate headquarters, we incurred an impairment charge on the right-of-use assets for leases related to our former corporate headquarters as well as other costs. See Note 17 for more information. (2) Related to 1900 Crystal Drive. (3) For the year ended December 31, 2019 includes integration and severance costs. For the year ended December 31, 2018 includes transition services provided by our former parent, and integration and severance costs. For the year ended December 31, 2017 includes 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 . (4) For the year ended December 31, 2019 represents a contribution to the Washington Housing Conservancy. For the year ended December 31, 2018 represents costs related to the successful pursuit of Amazon's additional headquarters at our properties in National Landing.

Interest Expense Interest Expen

Interest Expense Interest Expense	12 Months Ended
	Dec. 31, 2019
Interest Expense [Abstract]
Interest Income and Interest Expense Disclosure [Text Block]	Interest Expense The following is a summary of interest expense: Year Ended December 31, 2019 2018 2017 (In thousands) Interest expense $ 79,234 $ 91,651 $ 69,178 Amortization of deferred financing costs 3,217 4,661 3,011 Net loss (gain) on derivative financial instruments Net unrealized 50 (926 ) (1,348 ) Net realized — (135 ) 27 Capitalized interest (29,806 ) (20,804 ) (12,727 ) Interest expense $ 52,695 $ 74,447 $ 58,141

Earnings Per Common Share

Earnings Per Common Share	12 Months Ended
	Dec. 31, 2019
Earnings Per Share [Abstract]
Earnings Per Common Share	Earnings (Loss) Per Common Share Shareholders' Equity In April 2019, we closed an underwritten public offering of 11.5 million common shares (including 1.5 million common shares related to the exercise of the underwriters' option to cover overallotments) at $42.00 per share, which generated net proceeds, after deducting the underwriting discounts and commissions and other offering expenses, of $472.8 million . Earnings (Loss) Per Common Share The following is a summary of the calculation of basic and diluted earnings (loss) per common share and a reconciliation of the amounts of net income (loss) available to common shareholders used in calculating basic and diluted earnings per common share to net income (loss): Year Ended December 31, 2019 2018 2017 (In thousands, except per share amounts) Net income (loss) $ 74,144 $ 46,613 $ (79,084 ) Net (income) loss attributable to redeemable noncontrolling interests (8,573 ) (6,710 ) 7,328 Net loss attributable to noncontrolling interests — 21 3 Net income (loss) attributable to common shareholders 65,571 39,924 (71,753 ) Distributions to participating securities (2,489 ) (2,599 ) (1,655 ) Net income (loss) available to common shareholders — basic and diluted $ 63,082 $ 37,325 $ (73,408 ) Weighted average number of common shares outstanding — basic and diluted 130,687 119,176 105,359 Earnings (loss) per common share: Basic $ 0.48 $ 0.31 $ (0.70 ) Diluted $ 0.48 $ 0.31 (0.70 ) The effect of the redemption of OP Units and Time-Based LTIP Units that were outstanding as of December 31, 2019 and 2018 is excluded in the computation of diluted earnings per common share as the assumed exchange of such units for common shares on a one-for-one basis was antidilutive (the assumed redemption of these units would have no impact on the determination of diluted earnings per share). Since OP Units and Time-Based LTIP Units, which are held by noncontrolling interests, are attributed gains at an identical proportion to the common shareholders, the gains attributable and their equivalent weighted average OP Unit and Time-Based LTIP Unit impact are excluded from net income available to common shareholders and from the weighted average number of common shares outstanding in calculating diluted earnings per common share. Performance-Based LTIP Units, Special Performance-Based LTIP Units and Formation Awards, which totaled 4.7 million , 3.9 million and 3.3 million for each of the three years in the period ended December 31, 2019

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements Fair Value Measurements on a Recurring Basis To manage or hedge our exposure to interest rate risk, we follow established risk management policies and procedures, including the use of a variety of derivative financial instruments. We do not enter into derivative financial instruments for speculative purposes. As of December 31, 2019 and 2018 , we had various derivative financial instruments consisting of interest rate swap and cap agreements that are measured at fair value on a recurring basis. The net unrealized (loss) gain on our derivative financial instruments designated as cash flow hedges was $(17.7) million and $8.3 million as of December 31, 2019 and 2018 and was recorded in "Accumulated other comprehensive income (loss)" in our balance sheets, of which a portion was reclassified to "Redeemable noncontrolling interests." Within the next 12 months, we expect to reclassify $5.5 million as an increase to interest expense. The net unrealized (loss) gain on our derivative financial instruments not designated as cash flow hedges was $(50,000) , $926,000 and $1.3 million for each of the three years in the period ended December 31, 2019 , and was recorded in "Interest expense" in our statements of operations and "Net unrealized loss (gain) on ineffective derivative financial instruments" in our statements of cash flows. 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 is a summary of assets and liabilities measured at fair value on a recurring basis: Fair Value Measurements Total Level 1 Level 2 Level 3 December 31, 2019 (In thousands) Derivative financial instruments designated as cash flow hedges: Classified as liabilities in "Other liabilities, net" $ 17,440 — $ 17,440 — December 31, 2018 Derivative financial instruments designated as cash flow hedges: Classified as assets in "Other assets, net" $ 7,913 $ — $ 7,913 $ — Classified as liabilities in "Other liabilities, net" 1,723 — 1,723 — Derivative financial instruments not designated as cash flow hedges: Classified as assets in "Other assets, net" 2,470 — 2,470 — The fair values of our derivative financial instruments were determined using widely accepted valuation techniques, including discounted cash flow analysis on the expected cash flows of the derivative financial instrument. This analysis reflected the contractual terms of the derivative, including the period to maturity, and used observable market-based inputs, including interest rate market data and implied volatilities in such interest rates. While it was determined that the majority of the inputs used to value the derivatives fall within Level 2 of the fair value hierarchy under authoritative accounting guidance, the credit valuation adjustments associated with the derivatives also utilized Level 3 inputs, such as estimates of current credit spreads to evaluate the likelihood of default. However, as of December 31, 2019 and 2018 , the significance of the impact of the credit valuation adjustments on the overall valuation of the derivative financial instruments was assessed, and it was determined that these adjustments were not significant to the overall valuation of the derivative financial instruments. As a result, it was determined that the derivative financial instruments in their entirety should be classified in Level 2 of the fair value hierarchy. The net unrealized gains and losses included in "Other comprehensive income (loss)'' in our statements of comprehensive income (loss) for each of the three years in the period ended December 31, 2019 were attributable to the net change in unrealized gains or losses related to the interest rate swaps that were outstanding during those periods, none of which were reported in our statements of operations as the interest rate swaps were documented and qualified as hedging instruments. Fair Value Measurements on a Nonrecurring Basis Fair value measurements on a nonrecurring basis consist of the right-of-use asset related to our former corporate office lease, which we measured for impairment upon relocation to our new corporate headquarters in November 2019. Prior to the relocation, we leased office space in a building we owned through one of our unconsolidated real estate ventures. With the adoption of Topic 842 in January 2019, we recorded a right-of-use asset based on the expected future use of our former headquarters. Upon the relocation of our corporate headquarters, we impaired the right-of-use asset due to our change in use of the asset. The fair value of the right-of-use asset subsequent to the relocation was based on Level 3 inputs, including estimated sublease income and our incremental borrowing rate. For the year ended December 31, 2019, we incurred an impairment charge of $10.2 million and certain additional expenses related to the relocation of our corporate headquarters. There were no other assets measured at fair value on a nonrecurring basis as of December 31, 2019 and 2018. See Note 14 for more information. Financial Assets and Liabilities Not Measured at Fair Value As of December 31, 2019 and 2018 , all financial instruments and liabilities were reflected in our balance sheets at amounts which, in our estimation, reasonably approximated their fair values, except for the following: December 31, 2019 December 31, 2018 Carrying Amount (1) Fair Value Carrying Amount (1) Fair Value (In thousands) Financial liabilities: Mortgages payable $ 1,127,848 $ 1,162,890 $ 1,844,652 $ 1,870,078 Revolving credit facility 200,000 200,177 — — Unsecured term loans 300,000 300,607 300,000 300,727 ______________________________________ ( 1) The carrying amount consists of principal only.

Segment Information

Segment Information	12 Months Ended
	Dec. 31, 2019
Segment Reporting [Abstract]
Segment Information	Segment Information We review operating and financial data for each property on an individual basis; therefore, each of our individual properties is a separate operating segment. We defined 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 (commercial, multifamily, and third-party asset management and real estate services) based on the economic characteristics and nature of our assets and services. The CODM measures and evaluates the performance of our operating segments, with the exception of the third-party asset management and real estate services business, based on the net operating income ("NOI") of properties within each segment. NOI includes property rental revenue and other property revenue, and deducts property operating expenses and real estate taxes. With respect to the third-party asset management and real estate services business, the CODM reviews revenues streams generated by this segment ("Third-party real estate services, including reimbursements"), as well as the expenses attributable to the segment ("General and administrative: third-party real estate services"), which are both disclosed separately in our statements of operations. The following represents the components of revenue from our third-party real estate services business: Year Ended December 31, 2019 2018 2017 (In thousands) Property management fees $ 22,437 $ 24,831 $ 16,022 Asset management fees 14,045 14,910 10,083 Leasing fees 7,377 6,658 3,639 Development fees 15,655 7,592 3,653 Construction management fees 1,669 2,892 2,220 Other service revenue 4,269 2,801 712 Third-party real estate services revenue, excluding reimbursements 65,452 59,684 36,329 Reimbursements revenue (1) 55,434 39,015 26,907 Third-party real estate services revenue, including reimbursements $ 120,886 $ 98,699 $ 63,236 _________________ (1) Represents reimbursement of expenses incurred by us on behalf of third parties, including allocated payroll costs and amounts paid to third-party contractors for construction management projects. Management company assets primarily consist of management and leasing contracts with a net book value of $31.5 million and $38.6 million and are classified in "Other assets, net" in our balance sheets as of December 31, 2019 and 2018 . Consistent with internal reporting presented to our CODM and our definition of NOI, the third-party asset management and real estate services operating results are excluded from the NOI data below. The following is the reconciliation of net income attributable to common shareholders to consolidated NOI: Year Ended December 31, 2019 2018 2017 (In thousands) Net income (loss) attributable to common shareholders $ 65,571 $ 39,924 $ (71,753 ) Add: Depreciation and amortization expense 191,580 211,436 161,659 General and administrative expense: Corporate and other 46,822 33,728 39,350 Third-party real estate services 113,495 89,826 51,919 Share-based compensation related to Formation Transaction and special equity awards 42,162 36,030 29,251 Transaction and other costs 23,235 27,706 127,739 Interest expense 52,695 74,447 58,141 Loss on extinguishment of debt 5,805 5,153 701 Reduction of gain (gain) on bargain purchase — 7,606 (24,376 ) Income tax benefit (1,302 ) (738 ) (9,912 ) Net income (loss) attributable to redeemable noncontrolling 8,573 6,710 (7,328 ) Less: Third-party real estate services, including reimbursements 120,886 98,699 63,236 Other revenue (1) 7,638 6,358 5,167 Income (loss) from unconsolidated real estate ventures, net (1,395 ) 39,409 (4,143 ) Interest and other income, net 5,385 15,168 1,788 Gain on sale of real estate 104,991 52,183 — Net loss attributable to noncontrolling interests — 21 3 Consolidated NOI $ 311,131 $ 319,990 $ 289,340 __________________________ (1) Excludes parking revenue of $26.0 million , $25.7 million and $23.1 million for each of the three years in the period ended December 31, 2019 . The following is a summary of NOI by segment. Items classified in the Other column include future development assets, corporate entities and the elimination of intersegment activity. Year Ended December 31, 2019 Commercial Multifamily Other Total (In thousands) Property rentals revenue $ 383,311 $ 116,330 $ (6,368 ) $ 493,273 Other property revenue 25,593 380 — 25,973 Total property revenue 408,904 116,710 (6,368 ) 519,246 Property expense: — Property operating 113,177 35,236 (10,791 ) 137,622 Real estate taxes 50,115 15,021 5,357 70,493 Total property expense 163,292 50,257 (5,434 ) 208,115 Consolidated NOI $ 245,612 $ 66,453 $ (934 ) $ 311,131 Year Ended December 31, 2018 Commercial Multifamily Other Total (In thousands) Property rentals revenue $ 404,826 $ 108,989 $ (368 ) $ 513,447 Other property revenue 25,216 368 94 25,678 Total property revenue 430,042 109,357 (274 ) 539,125 Property expense: Property operating 118,288 31,502 (1,709 ) 148,081 Real estate taxes 53,324 14,280 3,450 71,054 Total property expense 171,612 45,782 1,741 219,135 Consolidated NOI $ 258,430 $ 63,575 $ (2,015 ) $ 319,990 Year Ended December 31, 2017 Commercial Multifamily Other Total (In thousands) Property rentals revenue $ 361,121 $ 91,294 $ (874 ) $ 451,541 Other property revenue 22,776 275 18 23,069 Total property revenue 383,897 91,569 (856 ) 474,610 Property expense: — Property operating 97,701 24,623 (3,488 ) 118,836 Real estate taxes 50,546 11,030 4,858 66,434 Total property expense 148,247 35,653 1,370 185,270 Consolidated NOI $ 235,650 $ 55,916 $ (2,226 ) $ 289,340 The following is a summary of certain balance sheet data by segment: Commercial Multifamily Other Total December 31, 2019 (In thousands) Real estate, at cost $ 3,415,294 $ 1,998,297 $ 361,928 $ 5,775,519 Investments in unconsolidated real estate ventures 396,199 107,882 38,945 543,026 Total assets (1) 3,361,122 1,682,872 942,257 5,986,251 December 31, 2018 Real estate, at cost $ 3,634,472 $ 1,656,974 $ 501,288 $ 5,792,734 Investments in unconsolidated real estate ventures 177,173 109,232 36,473 322,878 Total assets (1) 3,707,255 1,528,177 761,853 5,997,285 __________________________ (1)

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Insurance We maintain general liability insurance with limits of $200.0 million per occurrence and in the aggregate, and property and rental value insurance coverage with limits of $2.0 billion per occurrence, with sub-limits for certain perils such as floods and earthquakes on each of our properties. We also maintain coverage, through our wholly owned captive insurance subsidiary, for a portion of the first loss on the above limits and for both terrorist acts and for nuclear, biological, chemical or radiological terrorism events with limits of $2.0 billion per occurrence. These policies are partially reinsured by third-party insurance providers. We will continue to monitor the state of the insurance market and the scope and costs of coverage for acts of terrorism. We cannot anticipate what coverage will be available on commercially reasonable terms in the future. We are responsible for deductibles and losses in excess of the insurance coverage, which could be material. Our debt, consisting of mortgages payable secured by our properties, a revolving credit facility and unsecured term loans, contains customary covenants requiring adequate insurance coverage. Although we believe that we currently have adequate insurance coverage, we may not be able to obtain an equivalent amount of coverage at reasonable costs in the future. If lenders insist on greater coverage than we are able to obtain, it could adversely affect the ability to finance or refinance our properties. Construction Commitments As of December 31, 2019 , we have construction in progress that will require an additional $196.9 million to complete ( $160.1 million related to our consolidated entities and $36.8 million related to our unconsolidated real estate ventures at our share), based on our current plans and estimates, which we anticipate will be primarily expended over the next two to three years . These capital expenditures are generally due as the work is performed, and we expect to finance them with debt proceeds, proceeds from asset recapitalizations and sales, issuance and sale of equity securities and available cash. Environmental Matters Most of our assets have been subject, at some point, to environmental assessments that are intended to evaluate the environmental condition of the subject and surrounding assets. The environmental assessments did not reveal any material environmental contamination that we believe would have a material adverse effect on our overall business, financial condition or results of operations, or that have not been anticipated and remediated during site redevelopment as required by law. Nevertheless, there can be no assurance that the identification of new areas of contamination, changes in the extent or known scope of contamination, the discovery of additional sites or changes in cleanup requirements would not result in significant cost to us. Environmental liabilities total $17.9 million as of both December 31, 2019 and 2018 , and primarily relate to a liability to remediate pre-existing environmental matters at Potomac Yard Land Bay H, which was acquired in December 2018. Other There are various legal actions against us in the ordinary course of business. In our opinion, the outcome of such matters will not have a material adverse effect on our financial condition, results of operations or cash flows. From time to time, we (or ventures in which we have an ownership interest) have agreed, and may in the future agree with respect to unconsolidated real estate ventures, to (1) guarantee portions of the principal, interest and other amounts in connection with borrowings, (2) provide customary environmental indemnifications and nonrecourse carve-outs (e.g., guarantees against fraud, misrepresentation and bankruptcy) in connection with borrowings or (3) provide guarantees to lenders and other third parties for the completion of development projects. We customarily have agreements with our outside venture partners whereby the partners agree to reimburse the real estate venture or us for their share of any payments made under certain of these guarantees. At times, we also have agreements with certain of our outside venture partners whereby we agree to either indemnify the partners and/or the associated ventures with respect to certain contingent liabilities associated with operating assets or to reimburse our partner for its share of any payments made by them under certain guarantees. Guarantees (excluding environmental) customarily terminate either upon the satisfaction of specified circumstances or repayment of the underlying debt. Amounts that we may be required to pay in future periods in relation to guarantees associated with budget overruns or operating losses are not estimable. We also may guarantee portions of the principal, interest and other amounts in connection with the borrowings of our consolidated entities. As of December 31, 2019 , the aggregate amount of principal payment guarantees was $8.3 million for our consolidated entities. As of December 31, 2019 , we have additional capital commitments and certain recorded guarantees to our unconsolidated real estate ventures totaling $57.7 million . As of December 31, 2019 , we had no principal payment guarantees related to our unconsolidated real estate ventures.

Transactions with Vornado and R

Transactions with Vornado and Related Parties	12 Months Ended
	Dec. 31, 2019
Related Party Transactions [Abstract]
Related Party Transactions Disclosure [Text Block]	Transactions with Vornado and Related Parties Transactions with Vornado As described in Note 1, 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. In connection with the Formation Transaction, we entered into an agreement with Vornado under which Vornado provided operational support for a period that ended July 18, 2019. These services included information technology, financial reporting and payroll services. The charges for these services were based on an hourly or per transaction fee arrangement including reimbursement for overhead and out-of-pocket expenses totaling $3.6 million and $2.2 million for the years ended December 31, 2018 and 2017 . Charges for these services for 2019 were de minimis. Pursuant to agreements, we are providing Vornado with leasing and property management services for certain of its assets that were not part of the Separation. The total revenue related to these services was $2.0 million , $2.1 million and $779,000 for each of the three years in the period ended December 31, 2019 . We have agreements with Building Maintenance Services ("BMS"), a wholly owned subsidiary of Vornado, to supervise cleaning, engineering and security services at our properties. We paid BMS $21.8 million , $20.9 million and $13.6 million for each of the three years in the period ended December 31, 2019 , which are included in "Property operating expenses" in our statements of operations. In connection with the Formation Transaction, we have a Tax Matters Agreement with Vornado. See Note 19 for additional information. 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 our 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 for the year ended December 31, 2017 were $13.0 million . These allocated amounts are included as a component of "General and administrative expense: Corporate and other" expenses in our statement of operations and do not necessarily reflect what actual costs would have been if the Vornado Included Assets were a separate standalone public company. In August 2014, we completed a $185.0 million financing of the Universal Buildings, a 687,000 square foot office complex located in Washington, D.C. 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 2.90% due August 2019. At the Separation, Vornado repaid the outstanding balance of the loan and related accrued interest. We recognized interest income of $1.8 million for the year ended December 31, 2017 . In connection with the development of The Bartlett, prior to the Separation, 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. We incurred interest expense of $4.1 million for the year ended December 31, 2017 . In June 2016, the $115.0 million mortgage payable (including $608,000 of accrued interest) secured by the Bowen Building, a 231,000 square foot office building located in Washington, D.C., was repaid with the proceeds of a $115.6 million draw on our former parent's revolving credit facility. We repaid our former parent with amounts drawn under our revolving credit facility at the Combination. We incurred interest expense related to the mortgage payable of $1.3 million for the year ended December 31, 2017 . We had a consulting agreement with Mitchell Schear, a member of our Board of Trustees and formerly the president of Vornado’s Washington, D.C. segment. The consulting agreement expired on December 31, 2017 and provided for the payment of consulting fees and expenses at the rate of $169,400 per month for the 24 months following the Separation, including after the expiration of the consulting agreement. The amount due under this consulting agreement of $4.1 million was expensed in connection with the Combination. 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 for the year ended December 31, 2017 . Transactions with the JBG Legacy Funds and the Washington Housing Initiative ("WHI") Our third-party asset management and real estate services business provides fee-based real estate services to third parties, the JBG Legacy Funds and the WHI. 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, the general partner and managing member interests in the JBG Legacy Funds that were held by certain former JBG executives (and who became members of our management team and/or Board of Trustees) were not 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 entitle them to receive cash payments if the fund or real estate venture achieves certain return thresholds. The WHI was launched by us and the Federal City Council in June 2018 as a scalable market-driven model that uses private capital to help address the scarcity of housing for middle income families. To date, the WHI Impact Pool ("Impact Pool") completed closings of capital commitments totaling $104.8 million , which included a commitment from us of $10.2 million . We are the manager for the Impact Pool, which is the social impact investment vehicle of the WHI. The third-party real estate services revenue, including expense reimbursements, from the JBG Legacy Funds and the Impact Pool was $36.5 million , $33.8 million and $19.9 million for each of the three years in the period ended December 31, 2019 . As of December 31, 2019 and 2018 , we had receivables from the JBG Legacy Funds and the Impact Pool totaling $6.2 million and $3.6 million for such services. We rented our corporate offices from an unconsolidated real estate venture and made payments totaling $5.0 million , $4.9 million and $2.2 million for each of the three years in the period ended December 31, 2019

Quarterly Information (Notes)

Quarterly Information (Notes)	12 Months Ended
	Dec. 31, 2019
Quarterly Financial Information [Abstract]
Quarterly Financial Information [Text Block]	Quarterly Financial Data (unaudited) 2019 First Quarter (1) Second Quarter Third Quarter (2) Fourth Quarter (3) (In thousands, except per share data) Total revenue $ 155,199 $ 160,617 $ 167,077 $ 164,877 Net income (loss) 28,248 (3,328 ) 10,532 38,692 Net income (loss) attributable to common shareholders 24,861 (3,040 ) 9,360 34,390 Earnings (loss) per share: Basic 0.20 (0.03 ) 0.06 0.25 Diluted 0.20 (0.03 ) 0.06 0.25 _______________ (1) During the first quarter of 2019, we recognized a gain on the sale of real estate of $39.0 million from the sale of Commerce Executive/Commerce Metro Land. (2) During the third quarter of 2019, we recognized a gain on the sale of real estate of $8.1 million from the sale of 1600 K Street. (3) During the fourth quarter of 2019, we recognized an aggregate gain on the sale of real estate of $57.9 million , from the sale of Vienna Retail, and the partial sale and remeasurement of our remaining interest subsequent to the transfer of control in the real estate venture that owns Central Place Tower. Additionally, during the fourth quarter of 2019, we incurred an impairment charge of $10.2 million and certain additional expenses related to the relocation of our corporate headquarters. 2018 First Quarter Second Quarter (1) Third Quarter (2) Fourth Quarter (3) (In thousands, except per share data) Total revenue $ 163,037 $ 159,447 $ 158,443 $ 163,255 Net income (loss) (4,786 ) 24,023 26,382 994 Net income (loss) attributable to common shareholders (4,190 ) 20,574 22,830 710 Earnings (loss) per share: Basic (0.04 ) 0.17 0.19 (0.01 ) Diluted (0.04 ) 0.17 0.19 (0.01 ) ____________ (1) During the second quarter of 2018, we recognized an aggregate gain on the sale of real estate of $33.4 million from the sale of Summit I and II and the Bowen Building, a reduction to the gain on bargain purchase of $7.6 million related to the final adjustments to the fair value of certain asset acquired and liabilities assumed in the Formation Transaction and a loss on the extinguishment of debt of $4.5 million . (2) During the third quarter of 2018, we recognized a gain of $15.5 million related to the sale of our interest in a real estate venture that owned the Investment Building and a gain on the sale of real estate of $11.9 million from the sale of Executive Tower. (3) During the fourth quarter of 2018, we recognized a gain of $20.6 million from the sale of The Warner by our unconsolidated real estate venture with CPPIB, transaction and other costs of $15.6 million related to expenses incurred in connection with the Formation Transaction (including transition services provided by our former parent, integration costs, and severance costs), costs related to the pursuit of Amazon's additional headquarter, and costs related to other completed, potential and pursued transactions, and an aggregate gain on the sale of real estate of $6.4 million , from the sale of 1233 20th Street and the out-of-service portion of Falkland Chase - North.

Organization and Basis of Pre_2

Organization and Basis of Presentation Accounting (Policies)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Basis of Accounting [Text Block]	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 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 7 for additional information on our VIEs. The portions of the equity and net income of consolidated subsidiaries that are not attributable to JBG SMITH are presented separately as amounts attributable to noncontrolling interests in our consolidated and combined financial statements. References to the financial statements refer to our consolidated and combined financial statements as of December 31, 2019 and 2018 , and for each of the three years in the period ended December 31, 2019 . References to our balance sheets refer to our consolidated balance sheets as of December 31, 2019 and 2018 . References to our statements of operations refer to our consolidated and combined statements of operations for each of the three years in the period ended December 31, 2019 . References to our statements of comprehensive income (loss) refer to our consolidated and combined statements of comprehensive income (loss) for each of the three years in the period ended December 31, 2019 . References to our statements 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, 2019 .

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Use of Estimates, Policy [Policy Text Block]	Use of Estimates The preparation of the financial statements in conformity with GAAP requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the financial statements and the reported amounts of revenue and expenses during the reporting period. The most significant of these estimates include: (i) the underlying cash flows used in assessing impairment and (ii) the determination of useful lives for tangible and intangible assets. Actual results could differ from these estimates.
Business Combinations Policy [Policy Text Block]	Asset Acquisitions and Business Combinations We account for asset acquisitions, which includes the consolidation of previously unconsolidated real estate ventures, at cost, including transaction costs, plus the fair value of any assumed debt. 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 the date of acquisition. Based on these estimates, we allocate the purchase price, including all transaction costs related to the acquisition, to the identified assets acquired and liabilities assumed based on their relative fair value. We similarly account for business combinations by estimating the fair values of acquired tangible assets, identified intangible assets and liabilities, assumed debt and other liabilities, and noncontrolling interests, as applicable, based on our evaluation of information and estimates. Any excess of the purchase price over the estimated fair value of the net assets acquired is recorded as goodwill, and 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 assets acquired and liabilities assumed is received and the 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. Transaction costs are expensed as incurred and included in "Transaction and other costs" in our statements of operations. For both asset acquisitions and business combinations, the results of operations of acquisitions are prospectively included in our financial statements beginning with the date of the acquisition. The fair values of buildings are determined using the "as-if vacant" approach whereby we use discounted 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 lease) 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 lease intangible assets in "Other assets, net" in our balance sheets, and amounts allocated to below-market leases are recorded as lease intangible liabilities in "Other liabilities, net" in our balance sheets. These intangibles are amortized to "Property rentals revenue" 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 lease intangible assets in "Other assets, net" in our balance sheets and are amortized to "Depreciation and amortization expense" in our statements of operations over the remaining term of the existing lease; and • 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 expense" 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 is 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, Policy [Policy Text Block]	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 the asset is ready for its intended use, but no later than one year from substantial completion of major construction activities. General and administrative costs are expensed as incurred. Depreciation and amortization require 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 and amortization are 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. When assets are sold or retired, their costs and related accumulated depreciation are removed from the accounts with the resulting gains or losses reflected in net income or loss for the period. 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 activities. Our assets and related intangible assets are 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.
Cash and Cash Equivalents, Policy [Policy Text Block]	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.
Cash and Cash Equivalents, Restricted Cash and Cash Equivalents, Policy [Policy Text Block]	Restricted Cash Restricted cash consists primarily of proceeds from property dispositions held in escrow, 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.
Equity Method Investments [Policy Text Block]	Investments in Real Estate Ventures We analyze our real estate ventures to determine whether the entities should be consolidated. If it is determined that these entities are VIEs in which we have a variable interest, we assess whether we are the primary beneficiary of the VIE to determine whether it should be consolidated. We are not the primary beneficiary of entities when we do not have voting control, lack the power to direct the activities that most significantly impact the entity's economic performance, or the limited partners (or non-managing members) have substantive participatory rights. If it is determined that these entities are not VIEs, then the determination as to whether we consolidate is based on whether we have a controlling financial interest in the entity, which is based on 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 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 have significant influence but do not have a controlling financial interest. Significant influence is typically indicated through ownership of 20% or more of the voting interests. Under the equity method, we record our investments in these entities in "Investments in unconsolidated real estate ventures" on 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 when earned. 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. 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 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.
Intangible Assets, Finite-Lived, Policy [Policy Text Block]	Intangibles Intangible assets consist of in-place leases, below-market ground rent obligations, above-market real estate leases and options to enter into ground leases 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.
Real Estate Held for Development and Sale, Policy [Policy Text Block]	Assets Held for Sale Assets, primarily consisting of real estate, are 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.
Deferred Charges, Policy [Policy Text Block]	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.
Consolidation, Policy [Policy Text Block]	Noncontrolling Interests We identify our noncontrolling interests separately on our 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 our 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 became 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 our 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 12 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, Policy [Policy Text Block]	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 designation . 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 (loss) 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 creditworthiness 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 our statements of operations or as a component of comprehensive income and as a component of shareholders’ equity on our 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 our statements of operations in the period in which the change occurs.
Fair Value Measurement, Policy [Policy Text Block]	Fair Value of Assets and Liabilities Accounting Standards Codification ("ASC") 820 ("Topic 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). Topic 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, Policy [Policy Text Block]	Revenue Recognition We have leases with various tenants across our portfolio of properties, which generate rental income and operating cash flows for our benefit. Through these leases, we provide tenants with the right to control the use of our real estate, which tenants agree to use and control. The right to control our real estate conveys to our tenants substantially all of the economic benefits and the right to direct how and for what purpose the real estate is used throughout the period of use, thereby meeting the definition of a lease. Leases will be classified as either operating, sales-type or direct finance leases based on whether the lease is structured in effect as a financed purchase. Property rentals revenue includes base rent each tenant pays in accordance with the terms of its respective lease and is reported on a straight-line basis over the non-cancellable term of the lease, which includes the effects of periodic step-ups in rent and rent abatements under the lease. When a renewal option is included within the lease, we assess whether the option is reasonably certain of being exercised against relevant economic factors to determine whether the option period should be included as part of the lease term. Further, property rentals revenue includes tenant reimbursements revenue from the recovery of all or a portion of the operating expenses and real estate taxes of the respective assets. Tenant reimbursements, which vary each period, are non-lease components that are not the predominant activity within the contract. We combine certain lease and non-lease components of our operating leases. Non-lease components are recognized together with fixed base rent in "Property rentals revenue", as variable lease income in the same periods as the related expenses are incurred. Certain commercial leases may also provide for the payment by the lessee of additional rents based on a percentage of sales, which are recorded as variable lease income in the period the additional rents are earned. We commence rental revenue recognition when the tenant takes possession of the leased space or controls the physical use of the leased space and when the leased space is substantially ready for its intended use. In circumstances where we provide a tenant improvement allowance for improvements that are owned by the tenant, we recognize the allowance as a reduction of property rentals revenue on a straight-line basis over the term of the lease when the tenant takes possession of the space. Differences between rental revenue recognized and amounts due under the respective lease agreements are recorded as an increase or decrease to "Deferred rent receivable, net" on our balance sheets. Property rentals revenue also includes the amortization or accretion of acquired above-and below-market leases. We periodically evaluate the collectability of amounts due from tenants and recognize an adjustment to property rental revenue for the estimated losses resulting from the inability of tenants to make required payments under lease agreements. Any changes to the provision for lease revenue determined to be not probable of collection are included in "Property rentals revenue" in our statements of operations. We exercise judgment in assessing the probability of collection and consider payment history and current credit status in making this determination. Third-party real estate services revenue, including reimbursements, includes property and asset management fees, and transactional fees for leasing, acquisition, development and construction, financing, and legal services. These fees are determined in accordance with the terms specific to each arrangement and are recognized as the related services are performed. Development fees are earned from providing services to third-party property owners and our unconsolidated real estate ventures. The performance obligations associated with our development services contracts are satisfied over time and we recognize our development fee revenue using a time based measure of progress over the course of the development project due to the stand-ready nature of the promised services. The transaction prices for our performance obligations that are expected to be completed in greater than twelve months are variable based on the costs ultimately incurred to develop the underlying assets. Judgments impacting the timing and amount of revenue recognized from our development services contracts include the determination of the nature and number of performance obligations within a contract, estimates of total development project costs, from which the fees are typically derived, and estimates of the period of time over which the development services are expected to be performed, which is the period over which the revenue is recognized. We recognize development fees earned from unconsolidated joint venture projects to the extent of the third-party partners’ ownership interest.
Third-Party Real Estate Services Expenses [Policy Text Block]	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, including amounts paid to third-party contractors for construction management projects. 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.
Lessee, Leases [Policy Text Block]	Lessee Accounting We are obligated under non-cancellable operating leases, including ground leases on certain of our properties through 2061. When a renewal option is included within a lease, we assess whether the option is reasonably certain of being exercised against relevant economic factors to determine whether the option period should be included as part of the lease term. Lease payments associated with renewal periods that we are reasonably certain will be exercised are included in the measurement of the corresponding lease liability and right-of-use asset. Lease expense for our operating leases is recognized on a straight-line basis over the expected lease term and is included in our statements of operations in either "Property operating expenses" or "General and administrative expense" depending on the nature of the lease. Certain lease agreements include variable lease payments that, in the future, will vary based on changes in inflationary measures, market rates or our share of expenditures of the leased premises. Such variable payments are recognized in lease expense in the period in which the variability is determined. Certain lease agreements may also include various non-lease components that primarily relate to property operating expenses associated with our office leases, which also vary each period. We have elected the practical expedient which allows us not to separate lease and non-lease components for our ground and office leases and recognize variable non-lease components in lease expense when incurred.
Income Tax, Policy [Policy Text Block]	Income Taxes We have elected to be taxed as a REIT under sections 856-860 of the Internal Revenue Code of 1986, as amended (the "Code"). Under those sections, a REIT which distributes at least 90% of its REIT taxable income as dividends to its shareholders each year and which meets certain other conditions will not be taxed on that portion of its taxable income which is distributed to its shareholders. Prior to the Separation, Vornado operated as a REIT and distributed 100% of its REIT 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 currently adhere and intend to continue to adhere to these requirements and to maintain our REIT status in future periods. As a REIT, we can reduce our taxable income by distributing all or a portion of such taxable income 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 and such other factors as our Board of Trustees deems relevant. We also participate in the activities conducted by our subsidiary entities that 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 our financial statements, which will result in taxable or deductible amounts in the future. We provide for a valuation allowance for deferred income tax assets if we believe all or some portion of the deferred tax asset may not be realized. Any increase or decrease in the valuation allowance that results from a change in circumstances that causes a change in the estimated ability to realize the related deferred tax asset is included in deferred tax benefit (expense). Accounting Standards Codification 740 ("Topic 740"), Income Taxes, provides guidance for how uncertain tax positions should be recognized, measured, presented and disclosed in our financial statements. Topic 740 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 Per Share, Policy [Policy Text Block]	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 share-based compensation awards that entitle holders to receive non-forfeitable dividends, which include 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 (loss) per common share reflects the potential dilution of the assumed exchange of various unit and share-based compensation awards into common shares to the extent they are dilutive.
Compensation Related Costs, Policy [Policy Text Block]	Share-Based Compensation The fair value of share-based compensation awards granted to our trustees, management or employees is determined, depending on the type of award, using the Monte Carlo or Black-Scholes methods, which is intended to estimate the fair value of the awards at the grant date using dividend yields, expected volatilities that are primarily based on available implied data and peer group companies' historical data and post-vesting restriction periods. 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, LTIP Units with time-based vesting requirements ("Time-Based LTIP Units"), LTIP Units with performance-based vesting requirements ("Performance-Based LTIP Units") are recorded to "Redeemable noncontrolling interests" in our balance sheets.
New Accounting Pronouncements, Policy [Policy Text Block]	Recent Accounting Pronouncements Adoption of Accounting Standards Update 2016-02, Leases ("Topic 842") We enter into various lease agreements to make our properties available for use by third parties in exchange for cash consideration or to obtain the right to use properties owned by third parties to administer our business operations. We account for these leases under Topic 842, which we adopted as of January 1, 2019 using a modified retrospective approach and by applying the several transitional practical expedients including the Comparatives Under 840 expedient, the Relief Package for existing leases and the Easement expedient for existing easements, but not the Hindsight expedient. The Comparatives Under 840 expedient allows us not to recast our comparative periods in the period of adoption, and the Relief Package and Easement expedients allow us to maintain our historical accounting conclusions on current leases as of the date of adoption with respect to whether a contract contains a lease, what a lease’s classification should be, what initial direct costs are capitalizable and whether a land easement constituted a lease. The adoption of Topic 842 did not result in a material change to our recognition of property rental revenue and did not impact our opening accumulated deficit balance, but resulted in: (i) the inclusion of tenant reimbursements in "Property rentals revenue" in our statements of operations. Such amounts were previously separately presented as "Tenant reimbursements" in our statements of operations; (ii) the recognition, as of January 1, 2019, of right-of-use assets totaling $35.3 million in "Other assets, net" and lease liabilities totaling $37.9 million in "Other liabilities, net" in our accompanying balance sheet, associated with our corporate office lease and various ground leases for which we are the lessee. The initial right-of-use assets comprised $37.9 million of lease liabilities, $3.5 million of ground lease deferred rent payable reclassified from "Other liabilities, net" and $767,000 of identified net intangible assets and $140,000 of prepaid expenses both reclassified from "Other assets, net;" (iii) the inclusion as a deduction to revenue, as of January 1, 2019, of the impact of revenue deemed improbable of collection. Such amounts were previously recognized within "Property operating expenses" in our statements of operations; and (iv) the change, as of January 1, 2019, in our capitalization policy for direct leasing costs to include only incremental costs associated with successful leasing arrangements, which would not have been incurred if the leasing arrangements had not been obtained. As a result, we no longer capitalize internal leasing costs, which are now expensed as incurred within "General and administrative expense: corporate and other" in our statements of operations. Internal leasing costs capitalized for the years ended December 31, 2018 and 2017 totaled $6.5 million and $2.9 million . Lessor Accounting The following is a summary of revenue from our non-cancellable leases: Year Ended December 31, 2019 (In thousands) Property rentals: Fixed $ 458,329 Variable 34,944 Total $ 493,273 As of December 31, 2019 , the undiscounted cash flows to be received from lease payments under our operating leases on an annual basis for the next five years and thereafter are as follows: Year ending December 31, Amount (In thousands) 2020 $ 371,332 2021 297,603 2022 265,150 2023 220,722 2024 191,946 Thereafter 933,143 As of December 31, 2018 , future base rental revenue under our non-cancellable operating leases, as determined under ASC Topic 840, were as follows: Year ending December 31, Amount (In thousands) 2019 $ 377,427 2020 321,205 2021 287,463 2022 256,352 2023 215,203 Thereafter 1,188,767 Lessee Accounting As of December 31, 2019 , the weighted average discount rate used in calculating lease liabilities for our active operating leases was 5.4% , which had a weighted average remaining lease term of 23.9 years . As of December 31, 2019 , future minimum lease payments under our non-cancellable operating leases are as follows: Year ending December 31, Amount (In thousands) 2020 $ 5,999 2021 3,348 2022 3,064 2023 2,000 2024 2,061 Thereafter 36,580 Total future minimum lease payments 53,052 Imputed interest (24,576 ) Total (1) $ 28,476 ______________ (1) The total for operating leases of $28.5 million corresponds to lease liabilities related to operating right-of-use assets, which was included in "Other liabilities, net" as of December 31, 2019 . See Note 10 for additional information. As of December 31, 2018 , future minimum rental payments under our non-cancellable operating leases, capital leases and lease assumption liabilities, as determined under Topic 840, were as follows: Year ending December 31, Amount (In thousands) 2019 $ 13,991 2020 13,710 2021 13,395 2022 12,554 2023 9,489 Thereafter 55,780 Total $ 118,919 For the year ended December 31, 2019 , we incurred $2.3 million of fixed operating and finance lease costs and $1.3 million of variable operating lease costs.

Organization and Basis of Pre_3

Organization and Basis of Presentation Rental Revenue from USG (Tables)	12 Months Ended
	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Schedule of Revenue by Major Customers by Reporting Segments [Table Text Block]	Only the U.S. federal government accounted for 10% or more of our rental revenue, which consists of property rentals and other property revenue, as follows: Year Ended December 31, (Dollars in thousands) 2019 2018 2017 Rental revenue from the U.S. federal government $ 86,644 $ 94,822 $ 92,192 Percentage of commercial segment rental revenue 21.2 % 22.0 % 24.0 % Percentage of total rental revenue 16.7 % 17.6 % 19.4 %

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Operating Lease, Lease Income [Table Text Block]	The following is a summary of revenue from our non-cancellable leases: Year Ended December 31, 2019 (In thousands) Property rentals: Fixed $ 458,329 Variable 34,944 Total $ 493,273 As of December 31, 2019 , the undiscounted cash flows to be received from lease payments under our operating leases on an annual basis for the next five years and thereafter are as follows: Year ending December 31, Amount (In thousands) 2020 $ 371,332 2021 297,603 2022 265,150 2023 220,722 2024 191,946 Thereafter 933,143
Schedule of Future Minimum Lease Payments for Operating and Finance Leases [Table Text Block]	As of December 31, 2019 , future minimum lease payments under our non-cancellable operating leases are as follows: Year ending December 31, Amount (In thousands) 2020 $ 5,999 2021 3,348 2022 3,064 2023 2,000 2024 2,061 Thereafter 36,580 Total future minimum lease payments 53,052 Imputed interest (24,576 ) Total (1) $ 28,476 ______________ (1) The total for operating leases of $28.5 million corresponds to lease liabilities related to operating right-of-use assets, which was included in "Other liabilities, net" as of December 31, 2019 . See Note 10 for additional information.
Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block]	As of December 31, 2018 , future base rental revenue under our non-cancellable operating leases, as determined under ASC Topic 840, were as follows: Year ending December 31, Amount (In thousands) 2019 $ 377,427 2020 321,205 2021 287,463 2022 256,352 2023 215,203 Thereafter 1,188,767
Schedule of Future Minimum Lease Payments for Capital and Operating Leases [Table Text Block]	As of December 31, 2018 , future minimum rental payments under our non-cancellable operating leases, capital leases and lease assumption liabilities, as determined under Topic 840, were as follows: Year ending December 31, Amount (In thousands) 2019 $ 13,991 2020 13,710 2021 13,395 2022 12,554 2023 9,489 Thereafter 55,780 Total $ 118,919

The Combination (Tables)

The Combination (Tables)	12 Months Ended
	Dec. 31, 2019
Business Combinations [Abstract]
Schedule of Business Acquisitions, by Acquisition [Table Text Block]	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 (43,304 ) Portion of consideration attributable to performance of future services (3) (110,591 ) Fair value of common shares and OP Units purchase consideration $ 1,224,885 ____________________ (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 a 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 and special equity awards" in our statements of operations.
Schedule of Business Acquisitions, by Acquisition [Table Text Block]	The following allocation of the purchase price was based on the 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 unconsolidated real estate ventures 241,142 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) (48,127 ) Deferred tax liability (5) (18,610 ) Other liabilities acquired, net (60,048 ) Noncontrolling interests in consolidated subsidiaries (3,588 ) Net assets acquired 1,262,228 Gain on bargain purchase (6) 16,770 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 was paid in 2018, and a $34.1 million lease liability we assumed in relocating a tenant to one of our office buildings. The $34.1 million assumed lease liability was 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 of $24.4 million for the year ended December 31, 2017 because the fair value of the identifiable net assets acquired exceeded the purchase consideration. As a result of finalizing our fair value estimates used in the purchase price allocation related to the Combination, during the year ended December 31, 2018, we adjusted the fair value of certain assets acquired and liabilities assumed consisting of a decrease of $468,000 to investments in unconsolidated real estate ventures, an increase of $4.7 million to lease assumption liabilities and an increase of $2.4 million to other liabilities acquired, resulting in a reduction of the gain on bargain purchase of $7.6 million for the year ended December 31, 2018. The purchase consideration was based on the fair value of the common shares and OP Units issued in the Combination. We have concluded that all acquired assets and liabilities were recognized and that the valuation procedures and resulting estimates of fair values were appropriate.
Schedule of Finite-Lived Intangible Assets Acquired as Part of Business Combination [Table Text Block]	The following is a summary of the fair values of tangible and identified intangible assets and liabilities, which have definite lives: 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. 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 .

Acquisition, Disposals and As_2

Acquisition, Disposals and Assets Held for Sale (Tables)	12 Months Ended
	Dec. 31, 2019
Discontinued Operations and Disposal Groups [Abstract]
Disclosure of Long Lived Assets Held-for-sale [Table Text Block]	The following is a summary of assets held for sale: Assets Segment Location Total Square Feet Assets Held for Sale Liabilities Related to Assets Held for Sale (In thousands) December 31, 2019 Pen Place (1) Other Arlington, Virginia — $ 73,895 $ — Metropolitan Park (1) Other Arlington, Virginia — 94,517 — — $ 168,412 $ — December 31, 2018 Commerce Executive / Commerce Metro Land (2) Commercial Reston, Virginia 388,562 $ 78,981 $ 3,717 _______________ (1) In March 2019, we entered into agreements for the sale of Pen Place and Metropolitan Park, land sites having an aggregate estimated potential development density of up to approximately 4.1 million square feet, for approximately $293.9 million , subject to customary closing conditions. In January 2020 , we sold the Metropolitan Park land sites to Amazon for the gross sales price of $155.0 million , which represents an $11.0 million increase over the previously estimated contract value as the result of an increase in the approved development density on the sites. The sale was part of a like-kind exchange. See Note 7 for additional information. (2) As noted above, we sold Commerce Executive/Commerce Metro Land in February 2019
Disposal Groups, Including Discontinued Operations [Table Text Block]	The following is a summary of disposition activity for the year ended December 31, 2019 : Date Disposed Assets Segment Location Total Square Feet Gross Sales Price Cash Proceeds from Sale Gain on Sale of Real Estate (In thousands) February 4, 2019 Commerce Executive / Commerce Metro Land (1) (2) Commercial / Other Reston, Virginia 388,562 $ 114,950 $ 117,676 $ 39,033 July 31, 2019 1600 K Street Commercial Washington, D.C. 82,653 43,000 40,134 8,088 December 18, 2019 Vienna Retail Commercial Vienna, Virginia 8,584 7,400 7,005 4,514 479,799 $ 165,350 $ 164,815 51,635 December 12, 2019 Central Place Tower (3) Commercial Arlington, Virginia 53,356 Total $ 104,991 ______________ (1) The sale also included 894,000 square feet of estimated potential development density. The sale was part of a like-kind exchange. See Note 7 for additional information. (2) Cash proceeds include the reimbursement of $4.0 million of tenant improvement costs and leasing commissions paid by us prior to the closing. (3) Represents the gain, net of certain liabilities, on the sale of a 50.0% interest in the entity that owns Central Place Tower and the remeasurement of our remaining 50.0% interest to fair value. See Note 6 for additional information.

Tenant and Other Receivables,_2

Tenant and Other Receivables, Net (Tables)	12 Months Ended
	Dec. 31, 2019
Tenant and Other Receivables, Net [Abstract]
Schedule of Tenants and Other Receivables [Table Text Block]	The following is a summary of tenant and other receivables: December 31, 2019 2018 (In thousands) Tenants (1) $ 37,823 $ 31,362 Third-party real estate services 14,541 12,443 Other 577 9,463 Allowance for doubtful accounts (1) — (6,700 ) Total tenant and other receivables, net $ 52,941 $ 46,568

Investments in and Advances t_2

Investments in and Advances to Unconsolidated Real Estate Ventures (Tables)	12 Months Ended
	Dec. 31, 2019
Equity Method Investments and Joint Ventures [Abstract]
Composition of Investments	The following is a summary of the debt of our unconsolidated real estate ventures: Weighted Average Effective (1) December 31, 2019 2018 (In thousands) Variable rate (2) 4.10% $ 629,479 $ 461,704 Fixed rate (3) 3.98% 561,236 665,662 Unconsolidated real estate ventures - mortgages payable 1,190,715 1,127,366 Unamortized deferred financing costs (2,859 ) (1,998 ) Unconsolidated real estate ventures - mortgages payable, net (4) $ 1,187,856 $ 1,125,368 ______________ (1) Weighted average effective interest rate as of December 31, 2019 . (2) Includes variable rate mortgages payable with interest rate cap agreements. (3) Includes variable rate mortgages payable with interest rates fixed by interest rate swap agreements. (4) See Note 19 for additional information on guarantees of the debt of certain of our unconsolidated real estate ventures. The following is a summary of the financial information for our unconsolidated real estate ventures: December 31, 2019 2018 Combined balance sheet information: (In thousands) Real estate, net $ 2,493,961 $ 2,050,985 Other assets, net (1) 291,092 169,264 Total assets $ 2,785,053 $ 2,220,249 Borrowings, net $ 1,187,856 $ 1,125,368 Other liabilities, net (1) 168,243 94,845 Total liabilities 1,356,099 1,220,213 Total equity 1,428,954 1,000,036 Total liabilities and equity $ 2,785,053 $ 2,220,249 ______________ (1) On January 1, 2019, our unconsolidated real estate ventures adopted Topic 842, which required the ventures to record operating right-of-use assets totaling $52.4 million and related lease liabilities totaling $44.1 million . Year Ended December 31, 2019 2018 2017 Combined income statement information: (In thousands) Total revenue $ 266,653 $ 300,032 $ 135,256 Operating income (1) 18,041 56,262 14,741 Net loss (32,507 ) (1,155 ) (7,593 ) ______________ (1) Includes gain on sale of The Warner of $32.5 million recognized by our unconsolidated real estate venture with CPPIB during the year ended December 31, 2018 . The following is a summary of the composition of our investments in unconsolidated real estate ventures: Ownership Interest (1) December 31, Real Estate Venture Partners 2019 2018 (In thousands) Prudential Global Investment Management ("PGIM") 50.0% $ 215,624 $ — CPPIB 55.0% 109,911 97,521 Landmark 1.8% - 49.0% 77,944 84,320 CBREI Venture 5.0% - 64.0% 68,405 73,776 Berkshire Group 50.0% 46,391 43,937 Brandywine 30.0% 13,830 13,777 CIM Group ("CIM") and Pacific Life Insurance Company ("PacLife") 16.7% 10,385 9,339 Other 536 208 Total investments in unconsolidated real estate ventures $ 543,026 $ 322,878 _______________ (1) Ownership interests as of December 31, 2019 . We have multiple investments with certain venture partners with varying ownership interests.

Other Assets, Net (Tables)

Other Assets, Net (Tables)	12 Months Ended
	Dec. 31, 2019
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Summary of Other Assets, Net	The following is a summary of other assets, net: December 31, 2019 2018 (In thousands) Deferred leasing costs $ 205,830 $ 202,066 Accumulated amortization (79,814 ) (72,465 ) Deferred leasing costs, net $ 126,016 $ 129,601 Lease intangible assets, net 23,644 34,390 Other identified intangible assets, net 48,620 55,469 Operating right-of-use assets, net (1) 19,865 — Prepaid expenses 12,556 6,482 Deferred financing costs on credit facility, net 3,071 4,806 Deposits 3,210 3,633 Derivative agreements, at fair value — 10,383 Other 16,705 20,230 Total other assets, net $ 253,687 $ 264,994
Schedule of Lease Intangible Assets, Net	The following is a summary of the composition of lease intangible assets, net: December 31, 2019 2018 (in thousands) Lease intangible assets: In-place leases $ 33,812 $ 38,216 Above-market real estate leases 8,635 9,414 Below-market ground leases — 2,215 Total lease intangibles assets 42,447 49,845 Accumulated amortization: In-place leases 15,231 11,602 Above-market real estate leases 3,572 2,405 Below-market ground leases — 1,448 Total accumulated amortization 18,803 15,455 Lease intangible assets, net $ 23,644 $ 34,390
Schedule of Other Intangible Assets, Net	The following is a summary of the composition of other identified intangible assets, net: December 31, 2019 2018 (in thousands) Other identified intangible assets: Option to enter into ground lease $ 17,090 $ 17,090 Management and leasing contracts 48,900 48,900 Other 166 166 Total other identified intangibles assets 66,156 66,156 Accumulated amortization: Management and leasing contracts 17,385 10,297 Other 151 390 Total accumulated amortization 17,536 10,687 Other identified intangible assets, net $ 48,620 $ 55,469
Finite-lived Intangible Assets Amortization Expense [Table Text Block]	The following is a summary of amortization expense related to lease and other identified intangible assets: Year Ended December 31, 2019 2018 2017 (in thousands) In-place lease amortization (1) $ 7,375 $ 11,807 $ 10,216 Above-market real estate lease amortization (2) 1,730 2,390 1,428 Below-market ground lease amortization (3) — 85 87 Management and leasing contract amortization (1) 7,088 7,088 3,209 Other amortization (240 ) 191 14 Total lease and other identified intangible asset amortization expense $ 15,953 $ 21,561 $ 14,954 ___________________________________________ (1) Amounts are included in "Depreciation and amortization expense" 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 Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block]	The following is a summary of the estimated amortization of lease and other identified intangible assets for the next five years and thereafter as of December 31, 2019 : Year ending December 31, Amount (in thousands) 2020 $ 12,949 2021 9,993 2022 8,999 2023 8,510 2024 7,973 Thereafter 6,750 Total (1) $ 55,174 ___________________________________________ (1) Estimated amortization related to the option to enter into ground lease is not included within the amortization table above as the ground lease does not have a definite start date.

Debt (Tables)

Debt (Tables)	12 Months Ended
	Dec. 31, 2019
Debt Disclosure [Abstract]
Summary of Debt	The following is a summary of amounts outstanding under the credit facility: Effective December 31, Interest Rate (1) 2019 2018 (In thousands) Revolving credit facility (2) (3) (4) 2.86% $ 200,000 $ — Tranche A-1 Term Loan (5) 3.32% $ 100,000 $ 100,000 Tranche A-2 Term Loan (5) 3.74% 200,000 200,000 Unsecured term loans 300,000 300,000 Unamortized deferred financing costs, net (2,705 ) (2,871 ) Unsecured term loans, net $ 297,295 $ 297,129 __________________________ (1) Interest rate as of December 31, 2019 . (2) As of December 31, 2019 and 2018 , letters of credit with an aggregate face amount of $1.5 million and $5.7 million were provided under our revolving credit facility. (3) As of December 31, 2019 and 2018 , net deferred financing costs related to our revolving credit facility totaling $3.1 million and $4.8 million were included in "Other assets, net." (4) The interest rate for the revolving credit facility excludes a 0.15% The following is a summary of mortgages payable: Weighted Average (1) December 31, 2019 2018 (In thousands) Variable rate (2) 3.36% $ 2,200 $ 308,918 Fixed rate (3) 4.29% 1,125,648 1,535,734 Mortgages payable 1,127,848 1,844,652 Unamortized deferred financing costs and premium/ discount, net (2,071 ) (6,271 ) Mortgages payable, net $ 1,125,777 $ 1,838,381 __________________________ (1) Weighted average effective interest rate as of December 31, 2019 . (2) Includes a variable rate mortgage payable with an interest rate cap agreement as of December 31, 2018 . (3) Includes variable rate mortgages payable with interest rates fixed by interest rate swap agreements.
Schedule of Maturities of Long-term Debt [Table Text Block]	Principal Maturities Principal maturities of debt outstanding as of December 31, 2019 , including mortgages payable, revolving credit facility and the term loans, are as follows: Year ending December 31, Amount (In thousands) 2020 $ 99,341 2021 296,227 2022 107,500 2023 273,961 2024 334,290 Thereafter 516,529 Total $ 1,627,848

Other Liabilities, Net (Tables)

Other Liabilities, Net (Tables)	12 Months Ended
	Dec. 31, 2019
Other Liabilities Disclosure [Abstract]
Composition of Other Liabilities, Net	The following is a summary of other liabilities, net: December 31, 2019 2018 (In thousands) Lease intangible liabilities $ 38,577 $ 40,179 Accumulated amortization (26,253 ) (26,081 ) Lease intangible liabilities, net $ 12,324 $ 14,098 Prepaid rent 23,612 21,998 Lease assumption liabilities 17,589 23,105 Lease incentive liabilities 20,854 9,317 Lease liabilities related to operating right-of-use assets (1) 28,476 — Finance lease liability (2) — 15,704 Security deposits 16,348 17,696 Environmental liabilities 17,898 17,898 Ground lease deferred rent payable (3) — 3,510 Net deferred tax liability 5,542 6,878 Dividends payable 34,012 45,193 Derivative agreements, at fair value 17,440 1,723 Other 11,947 4,486 Total other liabilities, net $ 206,042 $ 181,606
Below Market Lease, Future Amortization Income [Table Text Block]	the estimated amortization of lease intangible liabilities for the next five years and thereafter as of December 31, 2019 ,: Year ending December 31, Amount (in thousands) 2020 $ 2,017 2021 1,800 2022 1,781 2023 1,773 2024 1,755 Thereafter 3,198 Total $ 12,324

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]	The following is a summary of our income tax benefit: Year Ended December 31, 2019 2018 2017 (in thousands) Current tax benefit (expense) $ (34 ) $ 20 $ (496 ) Deferred tax benefit 1,336 718 10,408 Income tax benefit $ 1,302 $ 738 $ 9,912
Schedule of Deferred Tax Assets and Liabilities [Table Text Block]	December 31, 2019 2018 (in thousands) Deferred tax assets: Accrued bonus $ 721 $ — Net operating loss 915 2,326 Deferred revenue 626 998 Bad debt expense — 583 Charitable contributions 435 — Other 217 198 Total deferred tax assets 2,914 4,105 Valuation allowance (523 ) (469 ) Total deferred tax assets, net of valuation allowance 2,391 3,636 Deferred tax liabilities: Management and leasing contracts (7,412 ) (9,905 ) Other (521 ) (609 ) Total deferred tax liabilities (7,933 ) (10,514 ) Net deferred tax liability $ (5,542 ) $ (6,878 )

Redeemable Noncontrolling Int_2

Redeemable Noncontrolling Interests (Tables)	12 Months Ended
	Dec. 31, 2019
Noncontrolling Interest [Abstract]
Redeemable Noncontrolling Interests	is a summary of the activity of redeemable noncontrolling interests: Year Ended December 31, 2019 2018 JBG SMITH LP Consolidated Real Estate Venture Total JBG SMITH LP Consolidated Real Estate Venture Total (In thousands) Balance as of beginning of period $ 552,159 $ 5,981 $ 558,140 $ 603,717 $ 5,412 $ 609,129 OP Unit redemptions (57,318 ) — (57,318 ) (109,208 ) — (109,208 ) LTIP Units issued in lieu of cash bonuses (1) 3,954 — 3,954 — — — Net income attributable to redeemable noncontrolling interests 8,566 7 8,573 6,641 69 6,710 Other comprehensive income (loss) (2,584 ) — (2,584 ) 1,384 — 1,384 Contributions (distributions) (15,325 ) 71 (15,254 ) (18,737 ) 500 (18,237 ) Share-based compensation expense 63,264 — 63,264 52,190 — 52,190 Adjustment to redemption value 53,983 — 53,983 16,172 — 16,172 Balance as of end of period $ 606,699 $ 6,059 $ 612,758 $ 552,159 $ 5,981 $ 558,140

Share-Based Payments (Tables)

Share-Based Payments (Tables)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Disclosure of Share-based Compensation Arrangements by Share-based Payment Award [Table Text Block]	The following is a summary of the significant assumptions used to value both the Performance-Based LTIP and Special Performance-Based LTIP Units: Year Ended December 31, 2019 2018 2017 Expected volatility 19.0% to 23.0% 19.9% to 26.0% 18.0 % Dividend yield 2.3% to 2.5% 2.5% to 2.7% 2.3 % Risk-free interest rate 2.3% to 2.6% 2.3% to 3.0% 1.5 % The following is a summary of both the Performance-Based LTIP and Special Performance-Based LTIP Units activity: Unvested Shares Weighted Average Grant-Date Fair Value Unvested at December 31, 2018 1,657,578 $ 18.27 Granted 478,411 19.49 Forfeited (18,054 ) 18.00 Unvested at December 31, 2019 2,117,935 18.55 Year Ended December 31, 2018 2017 Expected volatility 27.0% to 29.0% 26.0 % Dividend yield 2.5% to 2.7% 2.3 % Risk-free interest rate 2.8% to 3.0% 2.3 % Expected life 7 years 7 years The following is a summary of the Formation Awards activity: Unvested Shares Weighted Average Grant-Date Fair Value Unvested at December 31, 2018 2,655,394 $ 8.81 Vested (160,746 ) 8.84 Forfeited (9,702 ) 8.55 Unvested at December 31, 2019 2,484,946 8.81 Year Ended December 31, 2019 2018 2017 Expected volatility 18.0% to 24.0% 20.0% to 22.0% 17.0% to 19.0% Risk-free interest rate 2.3% to 2.6% 1.9% to 2.6% 1.3% to 1.5% Post-grant restriction periods 2 to 3 years 2 to 3 years 2 to 3 years The following is a summary of the Granted LTIP activity: Unvested Shares Weighted Average Grant-Date Fair Value Unvested at December 31, 2018 962,662 $ 34.03 Granted 493,777 34.40 Vested (360,703 ) 33.15 Forfeited (393 ) 34.52 Unvested at December 31, 2019 1,095,343 34.35 The total-grant date fair value of the Granted LTIPs that vested for each of the three years in the period ended December 31, 2019 was $12.0 million , $3.6 million and $2.5 million . In 2020, we issued 471,598 LTIP Units to management and employees with an estimated aggregate grant-date fair value of $18.3 million . The following is a summary of the OP Units activity: Unvested Shares Weighted Average Grant-Date Fair Value Unvested at December 31, 2018 2,999,987 $ 33.39 Vested (127,735 ) 33.39 Unvested at December 31, 2019 2,872,252 33.39	Year Ended December 31, 2019 2018 2017 Expected volatility 19.0% to 23.0% 19.9% to 26.0% 18.0 % Dividend yield 2.3% to 2.5% 2.5% to 2.7% 2.3 % Risk-free interest rate 2.3% to 2.6% 2.3% to 3.0% 1.5 % The following is a summary of both the Performance-Based LTIP and Special Performance-Based LTIP Units activity: Unvested Shares Weighted Average Grant-Date Fair Value Unvested at December 31, 2018 1,657,578 $ 18.27 Granted 478,411 19.49 Forfeited (18,054 ) 18.00 Unvested at December 31, 2019 2,117,935 18.55 In 2020, we issued 593,100 Performance-Based LTIP Units to management and employees with an estimated aggregate grant-date fair value of $11.1 million . JBG SMITH 2017 ESPP The JBG SMITH 2017 ESPP authorized the issuance of up to 2.1 million common shares. The ESPP provides eligible employees an option to purchase, through payroll deductions, our common shares at a discount of 15.0% of the closing price of a common share on relevant determination dates, provided that the fair market value of common shares, determined as of the first day of the relevant offering period, purchased by any eligible employee may not exceed $25,000 in any calendar year. The maximum aggregate number of common shares reserved for issuance under the ESPP will automatically increase on January 1 of each year, unless the Compensation Committee of the Board of Trustees determines to limit any such increase, by the lesser of (i) 0.10% of the total number of outstanding common shares on December 31 of the preceding calendar year or (ii) 206,600 common shares. Pursuant to the ESPP, employees purchased 47,022 and 20,178 common shares for $1.5 million and $597,000 during the years ended December 31, 2019 and 2018 . The following is a summary of the significant assumptions used to value the ESPP common shares using the Black-Scholes model: Year Ended December 31, 2019 2018 Expected volatility 18.0% to 28.0% 21.0 % Dividend yield 2.6% to 3.5% 2.5 % Risk-free interest rate 2.2% to 2.4% 2.0 % Expected life 6 months 6 months As of December 31, 2019 , there were 2.0 million common shares available for issuance under the ESPP.
Summary of Share-Based Compensation Expense	The following is a summary of share-based compensation expense: Year Ended December 31, 2019 2018 2017 (In thousands) Time-Based LTIP Units $ 11,386 $ 10,095 $ 2,211 Performance-Based LTIP Units 8,716 5,271 1,172 LTIP Units 1,000 794 — Other equity awards (1) 4,535 3,826 1,526 Share-based compensation expense - other 25,637 19,986 4,909 Formation Awards 5,734 5,606 5,169 OP Units (2) 29,826 29,455 21,467 LTIP Units (2) 456 277 2,615 Special Performance-Based LTIP Units (3) 2,843 323 — Special Time-Based LTIP Units (3) 3,303 369 — Share-based compensation related to Formation Transaction and special equity awards (4) 42,162 36,030 29,251 Total share-based compensation expense 67,799 56,016 34,160 Less amount capitalized (2,526 ) (3,341 ) (467 ) Share-based compensation expense $ 65,273 $ 52,675 $ 33,693 ______________________________________________ (1) For the years ended December 31, 2019 and 2018 , primarily includes compensation expense for certain executives who have elected to receive all or a portion of any cash bonus that may be paid in the subsequent year related to past service in the form of fully vested LTIP Units and related to our ESPP. For the year ended December 31, 2017, represents share-based compensation expense related to equity awards prior to the Formation Transaction. (2) Represents share-based compensation expense for LTIP Units and OP Units subject to post-Combination employment obligations. (3) Represents equity awards issued related to our successful pursuit of Amazon's additional headquarters in National Landing. (4) Included in "General and administrative expense: Share-based compensation related to Formation Transaction and special equity awards" in the accompanying statements of operations.

Transaction and Other Costs T_2

Transaction and Other Costs Transaction and Other Costs (Tables)	12 Months Ended
	Dec. 31, 2019
Other Income and Expenses [Abstract]
Other Operating Income and Expense [Text Block]	The following is a summary of transaction and other costs: Year Ended December 31, 2019 2018 2017 (In thousands) Relocation of corporate headquarters (1) $ 10,900 $ — $ — Demolition costs (2) 5,432 — — Formation transaction and integration costs (3) 5,252 15,907 127,739 Completed, potential and pursued transaction expenses 651 9,008 — Other (4) 1,000 2,791 — Transaction and other costs $ 23,235 $ 27,706 $ 127,739 __________________________ (1) In November 2019, we relocated our corporate headquarters. Upon the relocation of our corporate headquarters, we incurred an impairment charge on the right-of-use assets for leases related to our former corporate headquarters as well as other costs. See Note 17 for more information. (2) Related to 1900 Crystal Drive. (3) For the year ended December 31, 2019 includes integration and severance costs. For the year ended December 31, 2018 includes transition services provided by our former parent, and integration and severance costs. For the year ended December 31, 2017 includes 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 . (4) For the year ended December 31, 2019 represents a contribution to the Washington Housing Conservancy. For the year ended December 31, 2018 represents costs related to the successful pursuit of Amazon's additional headquarters at our properties in National Landing.

Interest Expense Interest Exp_2

Interest Expense Interest Expense (Tables)	12 Months Ended
	Dec. 31, 2019
Interest Expense [Abstract]
Interest Income and Interest Expense Disclosure [Table Text Block]	The following is a summary of interest expense: Year Ended December 31, 2019 2018 2017 (In thousands) Interest expense $ 79,234 $ 91,651 $ 69,178 Amortization of deferred financing costs 3,217 4,661 3,011 Net loss (gain) on derivative financial instruments Net unrealized 50 (926 ) (1,348 ) Net realized — (135 ) 27 Capitalized interest (29,806 ) (20,804 ) (12,727 ) Interest expense $ 52,695 $ 74,447 $ 58,141

Shareholders' Equity and Earnin

Shareholders' Equity and Earnings Per Common Share EPS (Tables)	12 Months Ended
	Dec. 31, 2019
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]	The following is a summary of the calculation of basic and diluted earnings (loss) per common share and a reconciliation of the amounts of net income (loss) available to common shareholders used in calculating basic and diluted earnings per common share to net income (loss): Year Ended December 31, 2019 2018 2017 (In thousands, except per share amounts) Net income (loss) $ 74,144 $ 46,613 $ (79,084 ) Net (income) loss attributable to redeemable noncontrolling interests (8,573 ) (6,710 ) 7,328 Net loss attributable to noncontrolling interests — 21 3 Net income (loss) attributable to common shareholders 65,571 39,924 (71,753 ) Distributions to participating securities (2,489 ) (2,599 ) (1,655 ) Net income (loss) available to common shareholders — basic and diluted $ 63,082 $ 37,325 $ (73,408 ) Weighted average number of common shares outstanding — basic and diluted 130,687 119,176 105,359 Earnings (loss) per common share: Basic $ 0.48 $ 0.31 $ (0.70 ) Diluted $ 0.48 $ 0.31 (0.70 )

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	The following is a summary of assets and liabilities measured at fair value on a recurring basis: Fair Value Measurements Total Level 1 Level 2 Level 3 December 31, 2019 (In thousands) Derivative financial instruments designated as cash flow hedges: Classified as liabilities in "Other liabilities, net" $ 17,440 — $ 17,440 — December 31, 2018 Derivative financial instruments designated as cash flow hedges: Classified as assets in "Other assets, net" $ 7,913 $ — $ 7,913 $ — Classified as liabilities in "Other liabilities, net" 1,723 — 1,723 — Derivative financial instruments not designated as cash flow hedges: Classified as assets in "Other assets, net" 2,470 — 2,470 —
Schedule of Financial Instruments and Liabilities as Reflected on Balance Sheet	As of December 31, 2019 and 2018 , all financial instruments and liabilities were reflected in our balance sheets at amounts which, in our estimation, reasonably approximated their fair values, except for the following: December 31, 2019 December 31, 2018 Carrying Amount (1) Fair Value Carrying Amount (1) Fair Value (In thousands) Financial liabilities: Mortgages payable $ 1,127,848 $ 1,162,890 $ 1,844,652 $ 1,870,078 Revolving credit facility 200,000 200,177 — — Unsecured term loans 300,000 300,607 300,000 300,727 ______________________________________ ( 1)

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2019
Segment Reporting [Abstract]
Disaggregation of Revenue [Table Text Block]	Year Ended December 31, 2019 2018 2017 (In thousands) Property management fees $ 22,437 $ 24,831 $ 16,022 Asset management fees 14,045 14,910 10,083 Leasing fees 7,377 6,658 3,639 Development fees 15,655 7,592 3,653 Construction management fees 1,669 2,892 2,220 Other service revenue 4,269 2,801 712 Third-party real estate services revenue, excluding reimbursements 65,452 59,684 36,329 Reimbursements revenue (1) 55,434 39,015 26,907 Third-party real estate services revenue, including reimbursements $ 120,886 $ 98,699 $ 63,236 _________________ (1) Represents reimbursement of expenses incurred by us on behalf of third parties, including allocated payroll costs and amounts paid to third-party contractors for construction management projects.
Segment information	The following is the reconciliation of net income attributable to common shareholders to consolidated NOI: Year Ended December 31, 2019 2018 2017 (In thousands) Net income (loss) attributable to common shareholders $ 65,571 $ 39,924 $ (71,753 ) Add: Depreciation and amortization expense 191,580 211,436 161,659 General and administrative expense: Corporate and other 46,822 33,728 39,350 Third-party real estate services 113,495 89,826 51,919 Share-based compensation related to Formation Transaction and special equity awards 42,162 36,030 29,251 Transaction and other costs 23,235 27,706 127,739 Interest expense 52,695 74,447 58,141 Loss on extinguishment of debt 5,805 5,153 701 Reduction of gain (gain) on bargain purchase — 7,606 (24,376 ) Income tax benefit (1,302 ) (738 ) (9,912 ) Net income (loss) attributable to redeemable noncontrolling 8,573 6,710 (7,328 ) Less: Third-party real estate services, including reimbursements 120,886 98,699 63,236 Other revenue (1) 7,638 6,358 5,167 Income (loss) from unconsolidated real estate ventures, net (1,395 ) 39,409 (4,143 ) Interest and other income, net 5,385 15,168 1,788 Gain on sale of real estate 104,991 52,183 — Net loss attributable to noncontrolling interests — 21 3 Consolidated NOI $ 311,131 $ 319,990 $ 289,340 __________________________ (1) Excludes parking revenue of $26.0 million , $25.7 million and $23.1 million for each of the three years in the period ended December 31, 2019 . The following is a summary of NOI by segment. Items classified in the Other column include future development assets, corporate entities and the elimination of intersegment activity. Year Ended December 31, 2019 Commercial Multifamily Other Total (In thousands) Property rentals revenue $ 383,311 $ 116,330 $ (6,368 ) $ 493,273 Other property revenue 25,593 380 — 25,973 Total property revenue 408,904 116,710 (6,368 ) 519,246 Property expense: — Property operating 113,177 35,236 (10,791 ) 137,622 Real estate taxes 50,115 15,021 5,357 70,493 Total property expense 163,292 50,257 (5,434 ) 208,115 Consolidated NOI $ 245,612 $ 66,453 $ (934 ) $ 311,131 Year Ended December 31, 2018 Commercial Multifamily Other Total (In thousands) Property rentals revenue $ 404,826 $ 108,989 $ (368 ) $ 513,447 Other property revenue 25,216 368 94 25,678 Total property revenue 430,042 109,357 (274 ) 539,125 Property expense: Property operating 118,288 31,502 (1,709 ) 148,081 Real estate taxes 53,324 14,280 3,450 71,054 Total property expense 171,612 45,782 1,741 219,135 Consolidated NOI $ 258,430 $ 63,575 $ (2,015 ) $ 319,990 Year Ended December 31, 2017 Commercial Multifamily Other Total (In thousands) Property rentals revenue $ 361,121 $ 91,294 $ (874 ) $ 451,541 Other property revenue 22,776 275 18 23,069 Total property revenue 383,897 91,569 (856 ) 474,610 Property expense: — Property operating 97,701 24,623 (3,488 ) 118,836 Real estate taxes 50,546 11,030 4,858 66,434 Total property expense 148,247 35,653 1,370 185,270 Consolidated NOI $ 235,650 $ 55,916 $ (2,226 ) $ 289,340 The following is a summary of certain balance sheet data by segment: Commercial Multifamily Other Total December 31, 2019 (In thousands) Real estate, at cost $ 3,415,294 $ 1,998,297 $ 361,928 $ 5,775,519 Investments in unconsolidated real estate ventures 396,199 107,882 38,945 543,026 Total assets (1) 3,361,122 1,682,872 942,257 5,986,251 December 31, 2018 Real estate, at cost $ 3,634,472 $ 1,656,974 $ 501,288 $ 5,792,734 Investments in unconsolidated real estate ventures 177,173 109,232 36,473 322,878 Total assets (1) 3,707,255 1,528,177 761,853 5,997,285 __________________________ (1)

Quarterly Information (Tables)

Quarterly Information (Tables)	12 Months Ended
	Dec. 31, 2019
Quarterly Financial Information [Abstract]
Quarterly Financial Information [Table Text Block]	2019 First Quarter (1) Second Quarter Third Quarter (2) Fourth Quarter (3) (In thousands, except per share data) Total revenue $ 155,199 $ 160,617 $ 167,077 $ 164,877 Net income (loss) 28,248 (3,328 ) 10,532 38,692 Net income (loss) attributable to common shareholders 24,861 (3,040 ) 9,360 34,390 Earnings (loss) per share: Basic 0.20 (0.03 ) 0.06 0.25 Diluted 0.20 (0.03 ) 0.06 0.25 _______________ (1) During the first quarter of 2019, we recognized a gain on the sale of real estate of $39.0 million from the sale of Commerce Executive/Commerce Metro Land. (2) During the third quarter of 2019, we recognized a gain on the sale of real estate of $8.1 million from the sale of 1600 K Street. (3) During the fourth quarter of 2019, we recognized an aggregate gain on the sale of real estate of $57.9 million , from the sale of Vienna Retail, and the partial sale and remeasurement of our remaining interest subsequent to the transfer of control in the real estate venture that owns Central Place Tower. Additionally, during the fourth quarter of 2019, we incurred an impairment charge of $10.2 million and certain additional expenses related to the relocation of our corporate headquarters. 2018 First Quarter Second Quarter (1) Third Quarter (2) Fourth Quarter (3) (In thousands, except per share data) Total revenue $ 163,037 $ 159,447 $ 158,443 $ 163,255 Net income (loss) (4,786 ) 24,023 26,382 994 Net income (loss) attributable to common shareholders (4,190 ) 20,574 22,830 710 Earnings (loss) per share: Basic (0.04 ) 0.17 0.19 (0.01 ) Diluted (0.04 ) 0.17 0.19 (0.01 ) ____________ (1) During the second quarter of 2018, we recognized an aggregate gain on the sale of real estate of $33.4 million from the sale of Summit I and II and the Bowen Building, a reduction to the gain on bargain purchase of $7.6 million related to the final adjustments to the fair value of certain asset acquired and liabilities assumed in the Formation Transaction and a loss on the extinguishment of debt of $4.5 million . (2) During the third quarter of 2018, we recognized a gain of $15.5 million related to the sale of our interest in a real estate venture that owned the Investment Building and a gain on the sale of real estate of $11.9 million from the sale of Executive Tower. (3) During the fourth quarter of 2018, we recognized a gain of $20.6 million from the sale of The Warner by our unconsolidated real estate venture with CPPIB, transaction and other costs of $15.6 million related to expenses incurred in connection with the Formation Transaction (including transition services provided by our former parent, integration costs, and severance costs), costs related to the pursuit of Amazon's additional headquarter, and costs related to other completed, potential and pursued transactions, and an aggregate gain on the sale of real estate of $6.4 million , from the sale of 1233 20th Street and the out-of-service portion of Falkland Chase - North.

Schedule II (Tables)

Schedule II (Tables)	12 Months Ended
	Dec. 31, 2019
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
SEC Schedule, 12-09, Schedule of Valuation and Qualifying Accounts Disclosure [Text Block]	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) Allowance for doubtful accounts (1) for year ended December 31: 2019 (2) $ — $ — $ — $ — $ — 2018 $ 6,285 $ 3,298 $ — $ (1,989 ) $ 7,594 2017 $ 4,526 $ 3,807 $ — $ (2,048 ) $ 6,285 _______________ (1) Includes allowance for doubtful accounts related to tenant and other receivables and deferred rent receivable. (2) Due to the adoption of Topic 842 as of January 1, 2019, we recognize changes in the assessment of collectability of tenant receivables as adjustments to the specific tenant’s receivable in our balance sheet and to "Property rentals revenue" in our statement of operations. Prior to the adoption of Topic 842, we recorded estimated losses on tenant receivables as an allowance for doubtful accounts in our balance sheets and to "Property operating expenses" in our statements of operations.

Schedule III (Tables)

Schedule III (Tables)	12 Months Ended
	Dec. 31, 2019
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Abstract]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation Disclosure [Text Block]	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 Commercial Operating Assets Universal Buildings $ — $ 69,393 $ 143,320 $ 26,516 $ 68,612 $ 170,617 $ 239,229 $ 59,237 1956 2007 2101 L Street 134,290 32,815 51,642 94,247 39,768 138,936 178,704 43,962 1975 2003 1730 M Street 47,500 10,095 17,541 17,207 10,687 34,156 44,843 14,154 2002, 2006 1700 M Street — 34,178 46,938 (26,130 ) 54,986 — 54,986 — 1964 2002 Courthouse Plaza 1 and 2 2,200 — 105,475 55,168 — 160,643 160,643 66,985 1989 2002 2121 Crystal Drive 133,960 21,503 87,329 31,234 22,361 117,705 140,066 51,920 1985 2002 2345 Crystal Drive — 23,126 93,918 47,870 23,882 141,032 164,914 59,290 1988 2002 2231 Crystal Drive — 20,611 83,705 22,116 21,311 105,121 126,432 46,350 1987 2002 1550 Crystal Drive — 17,988 70,525 27,967 18,175 98,305 116,480 42,082 1980 2002 RTC - West 92,846 30,326 134,108 11,160 30,425 145,169 175,594 16,791 1988 2017 RTC - West Retail 2,897 2,894 — 8,480 2,894 8,480 11,374 709 2017 2017 2011 Crystal Drive — 18,940 76,921 42,909 19,257 119,513 138,770 53,009 1984 2002 2451 Crystal Drive — 16,755 68,047 27,955 12,271 100,486 112,757 42,294 1990 2002 1235 S. Clark Street 78,000 15,826 56,090 31,131 16,444 86,603 103,047 36,804 1981 2002 241 18th Street S. — 13,867 54,169 40,229 17,018 91,247 108,265 36,854 1977 2002 251 18th Street S. 34,152 12,305 49,360 57,055 15,859 102,861 118,720 44,679 1975 2002 1215 S. Clark Street — 13,636 48,380 54,977 14,149 102,844 116,993 36,644 1983 2002 201 12th Street S. 32,728 14,766 52,750 24,350 15,257 76,609 91,866 33,639 1987 2002 800 North Glebe Road 107,500 28,168 140,983 2,290 28,168 143,273 171,441 14,785 2012 2017 2200 Crystal Drive — 13,104 30,050 34,931 13,565 64,520 78,085 21,773 1968 2002 1225 S. Clark Street — 11,176 43,495 24,169 11,601 67,239 78,840 28,228 1968 2002 1901 South Bell Street — 11,669 36,918 21,205 12,117 57,675 69,792 26,461 1982 2002 Crystal City Marriott — 8,000 47,191 22,029 8,045 69,175 77,220 24,859 1968 2004 2100 Crystal Drive — 10,287 23,590 31,845 10,686 55,036 65,722 25,709 1968 2002 1800 South Bell Street — — 28,702 8,370 213 36,859 37,072 3,807 1985 2002 200 12th Street S. 16,439 8,016 30,552 19,867 8,320 50,115 58,435 22,991 1967 2002 2001 Richmond Highway — 7,300 16,746 11,722 7,520 28,248 35,768 12,628 1969 2002 Crystal City Shops at 2100 — 4,059 9,309 3,664 4,049 12,983 17,032 5,712 1968 2002 Crystal Drive Retail — — 20,465 3,194 55 23,604 23,659 11,315 2003 2004 7200 Wisconsin Avenue — 34,683 92,059 10,430 34,683 102,489 137,172 9,361 1986 2017 One Democracy Plaza — — 33,628 8,494 — 42,122 42,122 25,817 1987 2002 4749 Bethesda Avenue Retail — 2,480 11,830 53 2,872 11,491 14,363 599 2016 2017 4747 Bethesda Avenue — 29,030 10,040 126,535 29,492 136,113 165,605 837 2019 2017 Commercial Construction Assets — 1770 Crystal Drive — 10,771 44,276 30,727 — 85,774 85,774 — 1974-1980 2002 Central District Retail — 4,194 — 48,807 — 53,001 53,001 — 2002 Multifamily Operating Assets — Fort Totten Square — 24,390 90,404 995 24,395 91,394 115,789 9,227 2015 2017 WestEnd25 96,227 67,049 5,039 111,284 68,213 115,159 183,372 30,478 2017 2019 F1RST Residences — 31,064 133,256 10 31,064 133,266 164,330 421 2009 2007 1221 Van Street — 27,386 63,775 27,162 28,198 90,125 118,323 7,905 2015 2017 North End Retail — 5,847 9,333 (301 ) 5,871 9,008 14,879 723 1960 2007 RiverHouse Apartments 307,710 118,421 125,078 90,748 138,946 195,301 334,247 70,549 2016 2007 The Bartlett — 41,687 — 225,461 41,868 225,280 267,148 21,948 2009 2017 220 20th Street — 8,434 19,340 101,416 8,761 120,429 129,190 34,674 1964 2002 2221 S. Clark Street — 7,405 16,981 41,453 7,583 58,256 65,839 8,936 1938 2017 Falkland Chase - South & West 40,001 18,530 44,232 1,062 18,642 45,182 63,824 5,017 1938 2017 Falkland Chase - North — 9,810 22,706 (2,072 ) 8,994 21,450 30,444 2,422 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 West Half — 45,668 17,902 156,076 47,342 172,304 219,646 1,986 2019 2017 Multifamily Construction Assets — 965 Florida Avenue — 14,306 — 120,570 — 134,876 134,876 — 2017 Atlantic Plumbing C — 47,678 13,952 94,669 — 156,299 156,299 — 2017 Future Development Assets — 1900 Crystal Drive — 16,811 53,187 (14,948 ) — 55,050 55,050 281 1968 2002 Capitol Point - North — 32,730 — 18,587 50,829 488 51,317 — 2017 Potomac Yard Land Bay G — 20,318 — 8,815 26,804 2,329 29,133 — Potomac Yard Land Bay H — 38,369 — 29 38,390 8 38,398 — RTC - West Land 1,398 29,956 — 3,798 29,956 3,798 33,754 — 2017 Square 649 — 15,550 6,451 (1,657 ) 12,672 7,672 20,344 487 2005 Other Future Development Assets — 76,771 15,286 30,549 77,185 45,421 122,606 444 Corporate — Corporate 500,000 — — 11,925 — 11,925 11,925 3,788 2017 1,627,848 1,250,141 2,496,974 2,028,404 1,240,455 4,535,064 5,775,519 1,119,571 Held for sale: Metropolitan Park (4) — 65,259 1,326 27,963 82,898 11,650 94,548 32 Pen Place — 104,473 55 (30,625 ) 61,970 11,933 73,903 9 — 169,732 1,381 (2,662 ) 144,868 23,583 168,451 41 $ 1,627,848 $ 1,419,873 $ 2,498,355 $ 2,025,742 $ 1,385,323 $ 4,558,647 $ 5,943,970 $ 1,119,612 Note: Depreciation of the buildings and improvements is calculated over lives ranging from the life of the lease to 40 years. The net basis of our assets and liabilities for tax reporting purposes is approximately $55.9 million higher than the amounts reported in our balance sheet as of December 31, 2019 . (1) Represents the contractual debt obligations. (2) Includes asset impairments recognized, amounts written off in connection with redevelopment activities, partial sale of assets and the reclassification of the net book value of assets to construction in progress. (3) Date of original construction, many assets have had substantial renovation or additional construction. See "Costs Capitalized Subsequent to Acquisition" column. (4) In January 2020 , we sold the Metropolitan Park land sites to Amazon for a gross sales price of $155.0 million . The following is a reconciliation of real estate and accumulated depreciation: Year Ended December 31, 2019 2018 2017 (In thousands) Real Estate: Balance at beginning of the year $ 5,895,953 $ 6,025,797 $ 4,155,391 Acquisitions 164,320 38,369 — Additions 469,450 358,976 1,926,404 Assets sold or written‑off (585,753 ) (527,189 ) (55,998 ) Balance at end of the year $ 5,943,970 $ 5,895,953 $ 6,025,797 Accumulated Depreciation: Balance at beginning of year $ 1,086,844 $ 1,011,330 $ 930,769 Depreciation expense 161,937 151,346 136,559 Accumulated depreciation on assets sold or written‑off (129,169 ) (75,832 ) (55,998 ) Balance at end of year $ 1,119,612 $ 1,086,844 $ 1,011,330

Organization and Basis of Pre_4

Organization and Basis of Presentation - Narrative (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)ft²building_unitproperties	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Real Estate Properties [Line Items]
Number of Real Estate Properties | properties	62
Parking Income | $	$ (26,000)	$ (25,700)	$ (23,100)
Reimbursements from Tenants | $	$ (55,434)	(39,015)	(26,907)
Asset under Construction
Real Estate Properties [Line Items]
Number of Real Estate Properties | properties	7
Future Development
Real Estate Properties [Line Items]
Number of Real Estate Properties | properties	40
Area of real estate property (in square feet) | ft²	21,900,000
Commercial Real Estate [Member]
Real Estate Properties [Line Items]
Number of Real Estate Properties | properties	44
Area of real estate property (in square feet) | ft²	12,700,000
Commercial Real Estate [Member] | Asset under Construction
Real Estate Properties [Line Items]
Number of Real Estate Properties | properties	4
Area of real estate property (in square feet) | ft²	943,000
Multifamily
Real Estate Properties [Line Items]
Number of Real Estate Properties | properties	18
Number of Units in Real Estate Property | building_unit	7,111
Multifamily | Asset under Construction
Real Estate Properties [Line Items]
Number of Real Estate Properties | properties	3
Number of Units in Real Estate Property | building_unit	1,011
Wholly Owned Properties | Future Development
Real Estate Properties [Line Items]
Area of real estate property (in square feet) | ft²	18,700,000
Wholly Owned Properties | Commercial Real Estate [Member]
Real Estate Properties [Line Items]
Area of real estate property (in square feet) | ft²	10,700,000
Wholly Owned Properties | Commercial Real Estate [Member] | Asset under Construction
Real Estate Properties [Line Items]
Area of real estate property (in square feet) | ft²	821,000
Wholly Owned Properties | Multifamily
Real Estate Properties [Line Items]
Number of Units in Real Estate Property | building_unit	5,327
Wholly Owned Properties | Multifamily | Asset under Construction
Real Estate Properties [Line Items]
Area of real estate property (in square feet) | ft²	833
Restatement Adjustment [Member]
Real Estate Properties [Line Items]
Parking Income | $		25,700	23,100
Reimbursements from Tenants | $		$ 39,300	$ 38,000
JBG Smith, LP
Real Estate Properties [Line Items]
Ownership interest by parent	89.90%

Organization and Basis of Pre_5

Organization and Basis of Presentation Schedule of Revenue by Major Customer (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disaggregation of Revenue [Line Items]
Revenues	$ 164,877	$ 167,077	$ 160,617	$ 155,199	$ 163,255	$ 158,443	$ 159,447	$ 163,037	$ 647,770	$ 644,182	$ 543,013
Government Contracts Concentration Risk [Member] | Sales Revenue, Segment [Member]
Disaggregation of Revenue [Line Items]
Revenues									$ 86,644	$ 94,822	$ 92,192
Concentration Risk, Percentage									21.20%	22.00%	24.00%
Government Contracts Concentration Risk [Member] | Sales Revenue, Net [Member]
Disaggregation of Revenue [Line Items]
Concentration Risk, Percentage									16.70%	17.60%	19.40%

Summary of Significant Accoun_4

Summary of Significant Accounting Policies Narratives (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2019
Deferred Costs, Leasing, Net		$ 6,500,000	$ 2,900,000
Operating Lease, Weighted Average Discount Rate, Percent	5.40%
Operating right-of-use assets, net (1)	$ 19,865,000	0		$ 35,300,000
Ground lease deferred rent payable	0	3,510,000		3,500,000
Other identified intangible assets, net	48,620,000	55,469,000		767,000
Prepaid expenses	$ 12,556,000	$ 6,482,000		$ 140,000
Operating Lease, Weighted Average Remaining Lease Term	23 years 10 months 24 days
Fixed Operating and Finance Lease, Cost	$ 2,300,000
Variable operating lease costs	$ 1,300,000

Summary of Significant Accoun_5

Summary of Significant Accounting Policies Property Rentals (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)
Accounting Policies [Abstract]
Property rentals - fixed	$ 458,329
Property rentals - variable	34,944
Property rentals - total	$ 493,273

Summary of Significant Accoun_6

Summary of Significant Accounting Policies Operating Lease, Payments to be Recevied (Details) $ in Thousands	Dec. 31, 2019USD ($)
Lessor, Lease, Description [Line Items]
2020	$ 371,332
2021	297,603
2022	265,150
2023	220,722
2024	191,946
Thereafter	$ 933,143

Summary of Significant Accoun_7

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

Summary of Significant Accoun_8

Summary of Significant Accounting Policies Lessee, Lease Liability, Maturity (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Operating Leases [Line Items]
2020	$ 5,999
2021	3,348
2022	3,064
2023	2,000
2024	2,061
Thereafter	36,580
Total future minimum lease payments	53,052
Imputed interest	(24,576)
Lease liabilities related to operating right-of-use assets (1)	28,476		$ 0
Other Liabilities [Member]
Operating Leases [Line Items]
Lease liabilities related to operating right-of-use assets (1)	$ 28,500	$ 37,900

Summary of Significant Accoun_9

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

The Combination Narrative (Deta

The Combination Narrative (Details) shares in Thousands, $ in Thousands	Jul. 18, 2017ft²building_unitpropertiesshares	Jun. 30, 2018USD ($)	Dec. 31, 2019USD ($)ft²building_unitproperties	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Bargain Purchase, Reduction Of Gain | $		$ (7,600)	$ 0	$ (7,606)	$ 24,376
Number of Real Estate Properties | properties			62
JBG Companies [Member]
Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual | $					71,300
Number of Real Estate Properties | properties	30
Number of Unrelated Owners	20
Number of Former Owners Turned Employees	19
Number of Former Owners Turned Board Members	3
Business Combination, Pro Forma Information, Earnings or Loss of Acquiree since Acquisition Date, Actual | $					$ 23,100
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares | shares	37,164
Commercial Real Estate [Member]
Number of Real Estate Properties | properties			44
Area of real estate property (in square feet)			12,700,000
Commercial Real Estate [Member] | JBG Companies [Member]
Number of Real Estate Properties | properties	21
Area of real estate property (in square feet)	4,100,000
Multifamily
Number of Real Estate Properties | properties			18
Number of Units in Real Estate Property | building_unit			7,111
Multifamily | JBG Companies [Member]
Number of Real Estate Properties | properties	9
Number of Units in Real Estate Property | building_unit	2,883
Asset under Construction | JBG Companies [Member]
Number of Real Estate Properties | properties	11
Area of real estate property (in square feet)	2,500,000
Near-Term Development [Member] | JBG Companies [Member]
Number of Real Estate Properties | properties	2
Area of real estate property (in square feet)	401,000
Future Development [Member] | JBG Companies [Member]
Number of Real Estate Properties | properties	26
Area of real estate property (in square feet)	11,700,000
Wholly Owned Properties | Commercial Real Estate [Member]
Area of real estate property (in square feet)			10,700,000
Wholly Owned Properties | Commercial Real Estate [Member] | JBG Companies [Member]
Area of real estate property (in square feet)	2,400,000
Wholly Owned Properties | Multifamily
Number of Units in Real Estate Property | building_unit			5,327
Wholly Owned Properties | Multifamily | JBG Companies [Member]
Number of Units in Real Estate Property | building_unit	1,099
Wholly Owned Properties | Asset under Construction | JBG Companies [Member]
Area of real estate property (in square feet)	2,200,000
Wholly Owned Properties | Near-Term Development [Member] | JBG Companies [Member]
Area of real estate property (in square feet)	242,000
Wholly Owned Properties | Future Development [Member] | JBG Companies [Member]
Area of real estate property (in square feet)	8,500,000

The Combination Fair Value of P

The Combination Fair Value of Purchase Consideration and Assets/Liabilities (Details)	Jul. 25, 2017USD ($)	Jul. 18, 2017USD ($)	Jun. 30, 2018USD ($)	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Cash					$ 28,000,000
Noncontrolling interests in consolidated subsidiaries					(5,550,000)
Repayment of notes receivable				$ 0	0	$ 50,934,000
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Bargain Purchase, Reduction Of Gain			$ (7,600,000)	$ 0	(7,606,000)	24,376,000
JBG Companies [Member]
Common shares and OP Units		$ 1,224,885,000
Cash		20,573,000
Total consideration paid		1,245,458,000
Land and improvements		338,072,000
Building and improvements		609,156,000
Construction in progress, including land		699,800,000
Leasehold improvements and equipment		7,890,000
Real estate		1,654,918,000
Cash		104,529,000
Restricted cash		13,460,000
Investments in unconsolidated real estate ventures		241,142,000
Identified intangible assets		138,371,000
Notes receivable (1)		50,934,000
Identified intangible liabilities		(8,687,000)
Mortgages payable assumed (2)		(768,523,000)
Capital lease obligations assumed (3)		(33,543,000)
Lease assumption liabilities (4)		(48,127,000)
Deferred tax liability (5)		(18,610,000)
Other liabilities acquired, net		(60,048,000)
Noncontrolling interests in consolidated subsidiaries		(3,588,000)
Net assets acquired		1,262,228,000
Gain on bargain purchase (6)		$ 16,770,000
Repayment of notes receivable						$ 50,900,000
Capital Leased Assets, Number of Units		2
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Lease Liabilities, Future Payments		$ 14,000,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Lease Liabilities, Relocation of Tenants		$ 34,100,000
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Real Estate Investments, Unconsolidated Real Estate Investments					468,000
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Lease Liabilities					4,700,000
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Current Liabilities, Other					$ 2,400,000
JBG Companies [Member] | Reston, Virginia [Member]
Capital Leased Assets, Number of Units	1
Payments to Acquire Land	$ 19,500,000

The Combination Fair Value of C

The Combination Fair Value of Common Shares And OP Unit Purchase Consideration (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	Jul. 18, 2017	Dec. 31, 2019	Dec. 31, 2018	Jul. 17, 2017
Common Stock, Shares, Outstanding		134,148	120,937
Business Combination, Contingent Consideration, Liability	$ (110,600)
JBG Companies [Member]
Common Stock, Shares, Outstanding				100,571
Business Acquisition, Equity Interest Issued or Issuable, Exchange Ratio	271.00%
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares	37,164
Business Acquisition, Equity Interest Issued or Issuable, Value Assigned	$ 1,378,780
Business Acquisition, Equity Interest Issued or Issuable, Fair Value Adjustment to OP Units Issued	(43,304)
Business Combination, Contingent Consideration, Liability	(110,591)
Common shares and OP Units	$ 1,224,885
Formation Awards
Business Acquisition, Equity Interest Issued or Issuable, Value Assigned Per Share			$ 34.40
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		10 years
Formation Awards | JBG Companies [Member]
Business Acquisition, Equity Interest Issued or Issuable, Value Assigned Per Share	$ 37.10
OP Units [Member] | Minimum
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	12 months
OP Units [Member] | Maximum
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	60 months

The Combination Fair Value of T

The Combination Fair Value of Tangible and Identified Intangible Assets and Liabilities (Details) - JBG Companies [Member] $ in Thousands	Jul. 18, 2017USD ($)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Buildings and Improvements	$ 543,584
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Tenant Improvements	65,572
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Buildings	609,156
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Leasehold Improvements	4,422
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Equipment	3,468
Business Combination, Recognized Identifiable Assets and Assumed Liabilities, Leasehold Improvements and Equipment	$ 7,890
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	10 years 3 months 18 days
Identified intangible assets	$ 138,371
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Liabilities	8,687
In-place lease amortization (1)
Finite-lived Intangible Assets Acquired	$ 60,317
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	6 years 4 months 24 days
Above-market real estate lease amortization (2)
Finite-lived Intangible Assets Acquired	$ 11,732
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	6 years 3 months 18 days
Below-market ground lease amortization (3)
Finite-lived Intangible Assets Acquired	$ 332
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	88 years 6 months
Option to enter into ground lease amortization (3)
Finite-lived Intangible Assets Acquired	$ 17,090
Management and leasing contract amortization (1)
Finite-lived Intangible Assets Acquired	$ 48,900
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	7 years 6 months
Minimum | Leasing Arrangement [Member]
Finite-Lived Intangible Asset, Useful Life	3 years
Maximum | Leasing Arrangement [Member]
Finite-Lived Intangible Asset, Useful Life	9 years
Building and Building Improvements [Member] | Minimum
Property, Plant and Equipment, Useful Life	3 years
Building and Building Improvements [Member] | Maximum
Property, Plant and Equipment, Useful Life	40 years
Equipment [Member]
Property, Plant and Equipment, Useful Life	5 years

Acquisition, Disposals and As_3

Acquisition, Disposals and Assets Held for Sale Acquisition (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)ft²building_unit	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Gain on sale of real estate	$ 104,991	$ 52,183	$ 0
Cash		$ 28,000
Business Acquisition, Transaction Costs	4,700
Central Place Tower [Member]
Gain on sale of real estate	53,400
Central Place Tower [Member] | Arlington, Virginia [Member]
Gain on sale of real estate	$ 53,356
Prudential Global Investment Management (PGIM) [Member]
Equity Method Investment, Ownership Percentage	50.00%
Area of real estate property (in square feet) | ft²	552,000
Multifamily
Number of Units in Real Estate Property | building_unit	7,111
Multifamily | F1RST Residences [Member] | Washington, D.C. [Member]
Number of Units in Real Estate Property | building_unit	325
Area of real estate property (in square feet) | ft²	21,000
Cash	$ 160,500
Occupancy, Percentage	91.70%

Acquisition, Disposals and As_4

Acquisition, Disposals and Assets Held for Sale Dispositions and Assets Held for Sale (Details) $ in Thousands	1 Months Ended	3 Months Ended		12 Months Ended
	Jan. 31, 2020USD ($)	Sep. 30, 2019USD ($)	Mar. 31, 2019USD ($)	Dec. 31, 2019USD ($)ft²	Dec. 31, 2018USD ($)ft²	Dec. 31, 2017USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from Sale of Property Held-for-sale					$ 427,400
Gain on sale of real estate				$ (104,991)	(52,183)	$ 0
Assets held for sale				168,412	78,981
Liabilities related to assets held for sale				$ 0	$ 3,717
Commerce Executive/Commerce Metro Land [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain on sale of real estate			$ (39,000)
Prudential Global Investment Management (PGIM) [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Area of real estate property (in square feet) | ft²				552,000
Equity Method Investment, Ownership Percentage Sold				50.00%
1600 K Street [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain on sale of real estate		$ (8,100)
Central Place Tower [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain on sale of real estate				$ (53,400)
Commerce Executive / Commerce Metro Land, 1600 K Street [Domain]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Area of real estate property (in square feet) | ft²				479,799
Proceeds from Sale of Property Held-for-sale				$ 165,350
Proceeds from sale of real estate				164,815
Gain on sale of real estate				$ (51,635)
Reston, Virginia [Member] | Commerce Executive/Commerce Metro Land [Member] | Commercial Segment [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Area of real estate property (in square feet) | ft²				388,562	388,562
Proceeds from Sale of Property Held-for-sale				$ 114,950
Proceeds from sale of real estate				117,676
Gain on sale of real estate				(39,033)
Assets held for sale					$ 78,981
Liabilities related to assets held for sale					$ 3,717
Proceeds from Sale of Real Estate Held-for-Investment, Reimbursements				$ 4,000
Washington, D.C. [Member] | 1600 K Street [Member] | Commercial Segment [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Area of real estate property (in square feet) | ft²				82,653
Proceeds from Sale of Property Held-for-sale				$ 43,000
Proceeds from sale of real estate				40,134
Gain on sale of real estate				$ (8,088)
Vienna, Virginia [Member] | Vienna Retail [Member] | Commercial Segment [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Area of real estate property (in square feet) | ft²				8,584
Proceeds from Sale of Property Held-for-sale				$ 7,400
Proceeds from sale of real estate				7,005
Gain on sale of real estate				(4,514)
National Landing, Virginia [Member] | Pen Place - Land Parcel [Member] | Other
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Assets held for sale				73,895
Liabilities related to assets held for sale				0
National Landing, Virginia [Member] | Metropolitan Park [Member] | Other
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Assets held for sale				94,517
Liabilities related to assets held for sale				$ 0
National Landing, Virginia [Member] | Penn Place and Met 6, 7 and 8 [Member] | Other
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from Sale of Property Held-for-sale			$ 293,900
Future Development
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Area of real estate property (in square feet) | ft²				21,900,000
Future Development | Commerce Executive/Commerce Metro Land [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Area of real estate property (in square feet) | ft²				894,000
Future Development | Penn Place and Met 6, 7 and 8 [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Area of real estate property (in square feet) | ft²				4,100,000
Subsequent Event [Member] | Metropolitan Park [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from Sale of Property Held-for-sale	$ 155,000
Subsequent Event [Member] | National Landing, Virginia [Member] | Metropolitan Park [Member] | Other
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Increase Over Previously Disclosed Contract Price	$ 11,000

Tenant and Other Receivables,_3

Tenant and Other Receivables, Net (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Tenant and Other Receivables, Net [Abstract]
Tenants	$ 37,823	$ 31,362
Third-party real estate services	14,541	12,443
Other	577	9,463
Allowance for doubtful accounts (1)	0	6,700
Allowance for doubtful accounts (1)	52,941	46,568
Losses on operating lease receivables	$ 1,560	$ 3,298	$ 3,807

Investments in and Advances t_3

Investments in and Advances to Unconsolidated Real Estate Ventures - Summary of Composition of Investments (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Schedule of Equity Method Investments [Line Items]
Total investments in and advances to unconsolidated real estate ventures	$ 543,026	$ 322,878
Prudential Global Investment Management (PGIM) [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	50.00%
Total investments in unconsolidated real estate ventures	$ 215,624	0
Canadian Pension Plan Investment Board (CPPIB)
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	55.00%
Total investments in unconsolidated real estate ventures	$ 109,911	97,521
Landmark
Schedule of Equity Method Investments [Line Items]
Total investments in unconsolidated real estate ventures	77,944	84,320
CBREI Venture
Schedule of Equity Method Investments [Line Items]
Total investments in unconsolidated real estate ventures	$ 68,405	73,776
Berkshire Group
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	50.00%
Total investments in unconsolidated real estate ventures	$ 46,391	43,937
Brandywine
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	30.00%
Total investments in unconsolidated real estate ventures	$ 13,830	$ 13,777
CIM/PacLife [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	16.70%	16.67%
Total investments in unconsolidated real estate ventures	$ 10,385	$ 9,339
Other
Schedule of Equity Method Investments [Line Items]
Total investments in unconsolidated real estate ventures	$ 536	$ 208
Minimum | Landmark
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	1.80%
Minimum | CBREI Venture
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	5.00%
Maximum | Landmark
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	49.00%
Maximum | CBREI Venture
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	64.00%

Investments in and Advances t_4

Investments in and Advances to Unconsolidated Real Estate Ventures - Narrative (Details) $ in Thousands	1 Months Ended	3 Months Ended		12 Months Ended
	Dec. 31, 2019USD ($)ft²	Dec. 31, 2018USD ($)ft²	Sep. 30, 2018USD ($)	Dec. 31, 2019USD ($)ft²	Dec. 31, 2018USD ($)ft²	Dec. 31, 2017USD ($)
Schedule of Equity Method Investments [Line Items]
Income (Loss) from Equity Method Investments				$ (1,395)	$ 39,409	$ (4,143)
Proceeds from sale of real estate				377,511	413,077	0
Gain on sale of real estate				104,991	52,183	0
Investments in Joint Ventures				181,813	95,923	0
Payments to Acquire Interest in Joint Venture					10,100
Investments in Unconsolidated Real Estate Ventures [Member]
Schedule of Equity Method Investments [Line Items]
Property Management Fee Revenue				$ 28,500	26,100	$ 12,900
Prudential Global Investment Management (PGIM) [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage Sold	50.00%			50.00%
Real Estate Investments, Unconsolidated Real Estate and Other Joint Ventures, Excluding Advances	$ 215,624	$ 0		$ 215,624	0
Area of real estate property (in square feet) | ft²	552,000			552,000
Proceeds from sale of real estate	$ 220,000
Equity Method Investment, Ownership Percentage	50.00%			50.00%
Central Place Tower [Member]
Schedule of Equity Method Investments [Line Items]
Gain on sale of real estate				$ 53,400
1101 17th Street [Member]
Schedule of Equity Method Investments [Line Items]
Real Estate Investments, Unconsolidated Real Estate and Other Joint Ventures, Excluding Advances	$ 0	$ 0		0	0
Income (Loss) from Equity Method Investments				6,400	$ 8,300
The Warner [Member]
Schedule of Equity Method Investments [Line Items]
Area of real estate property (in square feet) | ft²		583,000			583,000
Proceeds from sale of real estate					$ 376,500
Gain on sale of real estate					32,500
Equity Method Investment, Realized Gain (Loss) on Disposal		$ 20,600			20,600
Repayments of Secured Debt					270,500
1900 N Street [Member]
Schedule of Equity Method Investments [Line Items]
Investments in Joint Ventures					95,900
Long-term Purchase Commitment, Amount					$ 101,300
Equity Method Investment, Ownership Percentage		45.00%			45.00%
CIM/PacLife [Member]
Schedule of Equity Method Investments [Line Items]
Real Estate Investments, Unconsolidated Real Estate and Other Joint Ventures, Excluding Advances	$ 10,385	$ 9,339		$ 10,385	$ 9,339
Equity Method Investment, Ownership Percentage	16.70%	16.67%		16.70%	16.67%
Investment Building [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage Sold		5.00%			5.00%
Area of real estate property (in square feet) | ft²		401,000			401,000
Proceeds from sale of real estate					$ 24,600
Equity Method Investment, Realized Gain (Loss) on Disposal			$ 15,500		15,500
Investments in Unconsolidated Real Estate Ventures [Member] | 1101 17th Street [Member]
Schedule of Equity Method Investments [Line Items]
Income (Loss) from Equity Method Investments					$ 5,400
JBG Companies [Member] | 1900 N Street [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage		100.00%			100.00%
Equity Method Investment, Ownership Percentage After Funding Of Contributions	55.00%			55.00%
Legacy JBG Funds [Member] | CIM/PacLife [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage		47.64%			47.64%

Investments in and Advances t_5

Investments in and Advances to Unconsolidated Real Estate Ventures - Summary of Debt (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Equity Method Investments and Joint Ventures [Abstract]
Variable rate, weighted average interest rate	4.10%
Variable rate	$ 629,479	$ 461,704
Fixed rate, weighted average interest rate	3.98%
Fixed rate	$ 561,236	665,662
Unconsolidated real estate ventures - mortgages payable	1,190,715	1,127,366
Unamortized deferred financing costs	(2,859)	(1,998)
Unconsolidated real estate ventures - mortgages payable, net	$ 1,187,856	$ 1,125,368

Investments in and Advances t_6

Investments in and Advances to Unconsolidated Real Estate Ventures - Condensed Combined Financial Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2019
Equity Method Investment, Summarized Financial Information, Assets, Operating Leases, Right of Use Assets				$ 52,400
Operating Lease, Liability				$ 44,100
Combined balance sheet information:
Real estate, net	$ 2,493,961	$ 2,050,985
Other assets, net	291,092	169,264
Total assets	2,785,053	2,220,249
Borrowings, net	1,187,856	1,125,368
Other liabilities, net	168,243	94,845
Total liabilities	1,356,099	1,220,213
Total equity	1,428,954	1,000,036
Total liabilities and equity	2,785,053	2,220,249
Combined income statement information:
Total revenue	266,653	300,032	$ 135,256
Operating income	18,041	56,262	14,741
Net loss	$ (32,507)	$ (1,155)	$ (7,593)

Variable Interest Entities (Det

Variable Interest Entities (Details) $ in Millions	Dec. 31, 2019USD ($)properties	Dec. 31, 2018USD ($)
Variable Interest Entity [Line Items]
Number of Real Estate Properties | properties	62
Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Assets	$ 242.9	$ 232.8
Variable Interest Entity, Primary Beneficiary
Variable Interest Entity [Line Items]
Assets	136.8	94.8
Liabilities	$ 11.8	$ 43.4
Number of Real Estate Properties	2	2

Other Assets, Net Summary of Ot

Other Assets, Net Summary of Other Assets, Net (Details) - USD ($)	Dec. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Deferred Costs, Leasing, Gross	$ 205,830,000		$ 202,066,000
Deferred Costs, Leasing, Accumulated Amortization	79,814,000		72,465,000
Deferred leasing costs, net	126,016,000		129,601,000
Lease intangible assets, net	23,644,000		34,390,000
Other identified intangible assets, net	48,620,000	$ 767,000	55,469,000
Operating right-of-use assets, net (1)	19,865,000	35,300,000	0
Prepaid expenses	12,556,000	$ 140,000	6,482,000
Deferred financing costs on credit facility, net	3,071,000		4,806,000
Deposits	3,210,000		3,633,000
Derivative agreements, at fair value	0		10,383,000
Other	16,705,000		20,230,000
Total other assets, net	$ 253,687,000		$ 264,994,000

Other Assets, Net Lease Intangi

Other Assets, Net Lease Intangible Assets, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	$ 42,447	$ 49,845
Finite-Lived Intangible Assets, Accumulated Amortization	18,803	15,455
Finite-Lived Intangible Assets, Net	23,644	34,390
In-place lease amortization (1)
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	33,812	38,216
Finite-Lived Intangible Assets, Accumulated Amortization	15,231	11,602
Above-market real estate lease amortization (2)
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	8,635	9,414
Finite-Lived Intangible Assets, Accumulated Amortization	3,572	2,405
Below-market ground lease amortization (3)
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	0	2,215
Finite-Lived Intangible Assets, Accumulated Amortization	$ 0	$ 1,448

Other Assets, Net Other Intangi

Other Assets, Net Other Intangible Assets, Net (Details) - USD ($)	Dec. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Schedule of Other Intangible Assets [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	$ 66,156,000		$ 66,156,000
Intangible Assets, Accumulated Amortization	17,536,000		10,687,000
Other Intangible Assets, Net	48,620,000	$ 767,000	55,469,000
Option to enter into ground lease amortization (3)
Schedule of Other Intangible Assets [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	17,090,000		17,090,000
Management and leasing contract amortization (1)
Schedule of Other Intangible Assets [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	48,900,000		48,900,000
Intangible Assets, Accumulated Amortization	17,385,000		10,297,000
Other amortization (1)
Schedule of Other Intangible Assets [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	166,000		166,000
Intangible Assets, Accumulated Amortization	$ 151,000		$ 390,000

Other Assets, Net Lease and Oth

Other Assets, Net Lease and Other Intangible Asset Amortization Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Amortization of Intangible Assets	$ 15,953	$ 21,561	$ 14,954
In-place lease amortization (1)
Amortization of Intangible Assets	7,375	11,807	10,216
Above-market real estate lease amortization (2)
Amortization of Intangible Assets	1,730	2,390	1,428
Below-market ground lease amortization (3)
Amortization of Intangible Assets	0	85	87
Management and leasing contract amortization (1)
Amortization of Intangible Assets	7,088	7,088	3,209
Other amortization (1)
Amortization of Intangible Assets	$ (240)	$ 191	$ 14

Other Assets, Net Estimated Amo

Other Assets, Net Estimated Amortization of Intangible Assets (Details) $ in Thousands	Dec. 31, 2019USD ($)
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months	$ 12,949
Finite-Lived Intangible Assets, Amortization Expense, Year Two	9,993
Finite-Lived Intangible Assets, Amortization Expense, Year Three	8,999
Finite-Lived Intangible Assets, Amortization Expense, Year Four	8,510
Finite-Lived Intangible Assets, Amortization Expense, Year Five	7,973
Finite-Lived Intangible Assets, Amortization Expense, after Year Five	6,750
Intangible Assets, Net (Excluding Goodwill)	$ 55,174

Debt - Schedule of Mortgages Pa

Debt - Schedule of Mortgages Payable (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Mortgages payable	$ 1,627,848
Mortgages payable
Debt Instrument [Line Items]
Variable interest rate	3.36%
Variable rate amount	$ 2,200	$ 308,918
Fixed interest rate	4.29%
Fixed rate amount	$ 1,125,648	1,535,734
Mortgages payable	1,127,848	1,844,652
Unamortized deferred financing costs and premium/ discount, net	(2,071)	(6,271)
Mortgages payable, net	$ 1,125,777	$ 1,838,381

Debt - Narrative (Details)

Debt - Narrative (Details) $ in Thousands	Jul. 17, 2019	Feb. 25, 2020USD ($)	Jan. 31, 2020	Jun. 30, 2018USD ($)	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Mortgages and Line of Credit Facility [Line Items]
Loss on extinguishment of debt				$ 4,500	$ 5,805	$ 5,153	$ 701
Payment for Debt Extinguishment or Debt Prepayment Cost					2,900
Proceeds from Notes Payable					2,200	118,141	$ 366,239
Derivative Entered Into, Notional Value						381,300
Mortgages payable
Mortgages and Line of Credit Facility [Line Items]
Net carrying value of real estate collateralizing the mortgages payable					1,400,000	2,300,000
Repayments of Secured Debt					709,100	298,100
Derivative, Loss on Derivative					2,900
Proceeds from Notes Payable						118,100
Derivative, notional amount					867,600	1,300,000
Long-term Debt					1,125,777	1,838,381
Line of credit
Mortgages and Line of Credit Facility [Line Items]
Credit facility, maximum borrowing capacity					1,400,000
Line of credit | Revolving credit facility
Mortgages and Line of Credit Facility [Line Items]
Credit facility, maximum borrowing capacity					1,000,000
Long-term Debt					$ 200,000	0
Debt Instrument, Number Of Term Extension Options					2
Line of credit | Tranche A-1 Term Loan
Mortgages and Line of Credit Facility [Line Items]
Derivative, notional amount					$ 100,000	$ 100,000
Debt Instrument, Interest Rate During Period					2.12%	2.12%
Credit facility, maximum borrowing capacity					$ 200,000
Line of credit | Tranche A-2 Term Loan
Mortgages and Line of Credit Facility [Line Items]
Derivative, notional amount					$ 137,600
Debt Instrument, Interest Rate During Period					2.59%
Credit facility, maximum borrowing capacity					$ 200,000
London Interbank Offered Rate (LIBOR) [Member] | Line of credit | Tranche A-2 Term Loan
Mortgages and Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate, Reduction	40.00%
Other Expense [Member]
Mortgages and Line of Credit Facility [Line Items]
Loss on extinguishment of debt					$ (5,800)
Minimum | London Interbank Offered Rate (LIBOR) [Member] | Line of credit | Revolving credit facility
Mortgages and Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate					1.10%
Minimum | London Interbank Offered Rate (LIBOR) [Member] | Line of credit | Tranche A-1 Term Loan
Mortgages and Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate					1.20%
Minimum | London Interbank Offered Rate (LIBOR) [Member] | Line of credit | Tranche A-2 Term Loan
Mortgages and Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate					1.15%
Maximum | London Interbank Offered Rate (LIBOR) [Member] | Line of credit | Revolving credit facility
Mortgages and Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate					1.50%
Maximum | London Interbank Offered Rate (LIBOR) [Member] | Line of credit | Tranche A-1 Term Loan
Mortgages and Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate					1.70%
Maximum | London Interbank Offered Rate (LIBOR) [Member] | Line of credit | Tranche A-2 Term Loan
Mortgages and Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate					1.70%
Subsequent Event [Member] | Minimum | London Interbank Offered Rate (LIBOR) [Member] | Line of credit | Revolving credit facility
Mortgages and Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate			1.05%
Subsequent Event [Member] | Maximum | London Interbank Offered Rate (LIBOR) [Member] | Line of credit | Revolving credit facility
Mortgages and Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate			1.50%
4747 Bethesda Avenue [Member] | Subsequent Event [Member] | Mortgages payable
Mortgages and Line of Credit Facility [Line Items]
Proceeds from Notes Payable		$ 175,000
1730 M Street [Member] | Mortgages payable
Mortgages and Line of Credit Facility [Line Items]
Proceeds from Notes Payable						$ 47,500
Central Place Tower [Member] | Mortgages payable
Mortgages and Line of Credit Facility [Line Items]
Derivative, notional amount					$ 220,000

Debt - Summary of Amounts Outst

Debt - Summary of Amounts Outstanding under the Credit Facility (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Line of Credit Facility [Line Items]
Debt, gross	$ 1,627,848
Debt Issuance Costs, Line of Credit Arrangements, Net	3,071	$ 4,806
Tranche A-1 and A-2 Loans [Member]
Line of Credit Facility [Line Items]
Debt, gross	300,000	300,000
Unamortized deferred financing costs, net	(2,705)	(2,871)
Mortgages payable, net	$ 297,295	297,129
Line of credit | Revolving credit facility
Line of Credit Facility [Line Items]
Interest Rate (1)	2.86%
Mortgages payable, net	$ 200,000	0
Letters of Credit Outstanding, Amount	$ 1,500	5,700
Line of Credit Facility, Commitment Fee Percentage	0.15%
Line of credit | Tranche A-1 Term Loan
Line of Credit Facility [Line Items]
Interest Rate (1)	3.32%
Debt, gross	$ 100,000	100,000
Derivative, Notional Amount	$ 100,000	100,000
Line of credit | Tranche A-2 Term Loan
Line of Credit Facility [Line Items]
Interest Rate (1)	3.74%
Debt, gross	$ 200,000	$ 200,000
Derivative, Notional Amount	$ 137,600

Debt Principal Maturities (Deta

Debt Principal Maturities (Details) $ in Thousands	Dec. 31, 2019USD ($)
Debt Disclosure [Abstract]
2020	$ 99,341
2021	296,227
2022	107,500
2023	273,961
2024	334,290
Thereafter	516,529
Long-term Debt, Gross	$ 1,627,848

Other Liabilities, Net Summary

Other Liabilities, Net Summary of Other Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2019
Schedule of Other Liabilities [Line Items]
Below Market Lease, Gross	$ 38,577	$ 40,179
Below Market Lease, Accumulated Amortization	26,253	26,081
Lease intangible liabilities, net	12,324	14,098
Prepaid rent	23,612	21,998
Lease assumption liabilities	17,589	23,105
Lease incentive liabilities	20,854	9,317
Lease liabilities related to operating right-of-use assets (1)	28,476	0
Finance lease liability (2)	0	15,704
Security deposits	16,348	17,696
Environmental liabilities	17,898	17,898
Ground lease deferred rent payable	0	3,510		$ 3,500
Net deferred tax liability	5,542	6,878
Dividends payable	34,012	45,193
Derivative agreements, at fair value	17,440	1,723
Other	11,947	4,486
Total other liabilities, net	206,042	181,606
Amortization of Intangible Liabilities	$ 2,500	$ 2,600	$ 2,300
Prudential Global Investment Management (PGIM) [Member]
Schedule of Other Liabilities [Line Items]
Equity Method Investment, Ownership Percentage Sold	50.00%

Other Liabilities, Net Amortiza

Other Liabilities, Net Amortization of Intangible Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Other Liabilities Disclosure [Abstract]
2020	$ 2,017
2021	1,800
2022	1,781
2023	1,773
2024	1,755
2025	3,198
Thereafter	$ 12,324	$ 14,098

Income Taxes Narrative (Details

Income Taxes Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Deferred Tax Liabilities, Net	$ 5,542,000	$ 6,878,000
Common Stock, Dividends, Per Share, Declared	$ 0.90	$ 1	$ 0.45
Common Stock, Dividends, Per Share, Declared, Indicated Annual Amount		0.90
Common Stock, Dividends, Per Share, Declared, Additional Declared		0.10
Common Stock, Dividends, Per Share, Declared, Taxable as Ordinary Income in the Current Year	0.333	0.531	0.385
Common Stock, Dividends, Per Share, Declared, Taxable as Return of Capital	0.342	$ 0.469	$ 0.065
Common Stock, Dividends, Per Share, Declared, Taxable Status to be Determined in Next Year	$ 0.225
Income Tax Expense (Benefit)	$ (1,302,000)	$ (738,000)	$ (9,912,000)
Tax Cuts and Jobs Act, Change in Tax Rate, Deferred Tax Liability, Income Taxes			$ 3,900,000
Operating Loss Carryforwards	3,600,000
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Federal Income Tax Basis Difference	55,900,000
Subsidiaries [Member]
Income Tax Expense (Benefit)	$ 0
Minimum [Member]
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2038
Maximum
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2039

Income Taxes Schedule of Compon

Income Taxes Schedule of Components of Income Tax Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Current Income Tax Expense (Benefit)	$ 34	$ (20)	$ 496
Deferred Income Tax Expense (Benefit)	(1,336)	(718)	(10,408)
Income Tax Expense (Benefit)	$ (1,302)	$ (738)	$ (9,912)

Income Taxes Schedule of Deferr

Income Taxes Schedule of Deferred Tax Assets and LIabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Employee Compensation	$ 721	$ 0
Deferred Tax Assets, Charitable Contribution Carryforwards	435	0
Deferred Tax Assets, Operating Loss Carryforwards	915	2,326
Deferred Tax Assets, Deferred Income	626	998
Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals	0	583
Deferred Tax Assets, Tax Deferred Expense, Other	217	198
Deferred Tax Assets, Gross	2,914	4,105
Deferred Tax Assets, Valuation Allowance	523	469
Deferred Tax Assets, Net of Valuation Allowance	2,391	3,636
Deferred Tax Liabilities, Leasing Arrangements	7,412	9,905
Deferred Tax Liabilities, Other	521	609
Deferred Tax Liabilities, Gross	7,933	10,514
Deferred Tax Liabilities, Net	$ 5,542	$ 6,878

Redeemable Noncontrolling Int_3

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

Redeemable Noncontrolling Int_4

Redeemable Noncontrolling Interests - Summary of the Activity of Redeemable Noncontrolling Interests (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Temporary Equity
Beginning Balance	$ 558,140	$ 609,129
Fair value of OP Unit redemptions	(57,318)	(109,208)	$ 0
LTIP Units issued in lieu of cash bonuses (1)	3,954	0
Net income (loss) attributable to redeemable noncontrolling interests	8,573	6,710
Other comprehensive income	(2,584)	1,384
Temporary Equity, Contributions (Distributions)	(15,254)	(18,237)
Share-based compensation expense	63,264	52,190
Adjustment to redemption value	53,983	16,172
Ending Balance	612,758	558,140	609,129
JBG Smith, LP
Temporary Equity
Beginning Balance	552,159	603,717
Fair value of OP Unit redemptions	(57,318)	(109,208)
LTIP Units issued in lieu of cash bonuses (1)	3,954	0
Net income (loss) attributable to redeemable noncontrolling interests	8,566	6,641
Other comprehensive income	(2,584)	1,384
Temporary Equity, Contributions (Distributions)	(15,325)	(18,737)
Share-based compensation expense	63,264	52,190
Adjustment to redemption value	53,983	16,172
Ending Balance	606,699	552,159	603,717
Consolidated Real Estate Venture
Temporary Equity
Beginning Balance	5,981	5,412
Fair value of OP Unit redemptions	0	0
LTIP Units issued in lieu of cash bonuses (1)	0	0
Net income (loss) attributable to redeemable noncontrolling interests	7	69
Other comprehensive income	0	0
Temporary Equity, Contributions (Distributions)	71	500
Share-based compensation expense	0	0
Adjustment to redemption value	0	0
Ending Balance	$ 6,059	$ 5,981	$ 5,412

Share-Based Payments OP Units (

Share-Based Payments OP Units (Details) - USD ($) $ / shares in Units, $ in Thousands	Jul. 18, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Business Combination, Contingent Consideration, Liability	$ 110,600
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value		$ 33.39
OP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number		2,872,252	2,999,987
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period		(127,735)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value		$ 33.39	$ 33.39
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value		$ 4,300	$ 3,200	$ 7,200
JBG Companies [Member]
Business Combination, Contingent Consideration, Liability	$ 110,591
JBG Companies [Member] | OP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	3,300,000
Minimum [Member] | OP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	12 months
Maximum | OP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	60 months
Measurement Input, Price Volatility [Member] | OP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Minimum	18.00%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Maximum	27.00%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate, Minimum	1.30%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate, Maximum	1.50%
Measurement Input, Expected Term [Member] | Minimum [Member] | OP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term	1 year
Measurement Input, Expected Term [Member] | Maximum | OP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term	3 years

Share-Based Payments Formation

Share-Based Payments Formation Awards (Details) - USD ($)	Jul. 18, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value		$ 33.39
Omnibus Share Plan, 2017 [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	10,300,000	3,900,000
Performance Shares and Special Performance-Based LTIP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period		478,411
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		3 years
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number		2,117,935	1,657,578
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value		$ 18.55	$ 18.27
Deferred Compensation Arrangement with Individual, Fair Value of Shares Issued		$ 9,300,000	$ 21,100,000	$ 9,700,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value		$ 18
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period		(18,054)
Formation Awards
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period			93,784
Stock Granted, Value, Share-based Compensation, Gross			$ 3,200,000
Business Acquisition, Equity Interest Issued or Issuable, Value Assigned Per Share			$ 34.40
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		10 years
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number		2,484,946	2,655,394
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value		$ 8.81	$ 8.81
Deferred Compensation Arrangement with Individual, Fair Value of Shares Issued			$ 725,000	$ 23,700,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period		(160,746)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value		$ 8.55
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value		$ 8.84
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period		(9,702)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value		$ 1,400,000	$ 333,000
JBG Companies [Member] | Formation Awards
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	2,700,000
Stock Granted, Value, Share-based Compensation, Gross	$ 100,000,000
Business Acquisition, Equity Interest Issued or Issuable, Value Assigned Per Share	$ 37.10
Share-based Compensation Award, Tranche One [Member] | Formation Awards
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage		25.00%
Share-based Compensation Award, Tranche Three [Member] | Formation Awards
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage		50.00%
Measurement Input, Price Volatility [Member] | Performance Shares and Special Performance-Based LTIP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Minimum		19.00%	19.90%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Maximum		23.00%	26.00%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Maximum				18.00%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate				2.30%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate				1.50%
Measurement Input, Price Volatility [Member] | Formation Awards
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Minimum			27.00%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Maximum			29.00%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Maximum				26.00%
Measurement Input, Expected Dividend Rate [Member] | Formation Awards
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate				2.30%
Measurement Input, Risk Free Interest Rate [Member] | Performance Shares and Special Performance-Based LTIP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate, Minimum		2.30%	2.30%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate, Maximum		2.60%	3.00%
Measurement Input, Risk Free Interest Rate [Member] | Formation Awards
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate				2.30%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate, Minimum			2.80%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate, Maximum			3.00%
Minimum [Member] | Measurement Input, Expected Dividend Rate [Member] | Performance Shares and Special Performance-Based LTIP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate		2.30%	2.50%
Minimum [Member] | Measurement Input, Expected Dividend Rate [Member] | Formation Awards
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate			2.50%
Maximum | Measurement Input, Expected Dividend Rate [Member] | Performance Shares and Special Performance-Based LTIP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate		2.50%	2.70%
Maximum | Measurement Input, Expected Dividend Rate [Member] | Formation Awards
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate			2.70%

Share-Based Payments - LTIP and

Share-Based Payments - LTIP and Time-Based LTIP Units (Details)	Jul. 18, 2017USD ($)shares	Feb. 25, 2020USD ($)shares	Dec. 31, 2019USD ($)$ / sharesshares	Dec. 31, 2018USD ($)$ / sharesshares	Dec. 31, 2017USD ($)$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Compensation expense recognition period (in years)			2 years 2 months 12 days
Weighted Average Grant-Date Fair Value
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value | $ / shares			$ 33.39
Special Performance-Based LTIP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Equity grants (in shares)				511,555
Compensation expense recognition period (in years)			5 years
LTIP and Time-Based LTIP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value | $			$ 12,000,000	$ 3,600,000	$ 2,500,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number			1,095,343	962,662
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Equity grants (in shares)			493,777
Fair value of awards on grant date | $			$ 17,000,000	$ 25,500,000	$ 13,700,000
Weighted Average Grant-Date Fair Value
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value | $ / shares			$ 34.40
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value | $ / shares			$ 34.35	$ 34.03
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period			360,703
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value | $ / shares			$ 33.15
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period			(393)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value | $ / shares			$ 34.52
Special Time-Based LTIP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Compensation expense recognition period (in years)			5 years
Management [Member] | Time-Based LTIP Units
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Equity grants (in shares)			351,982	367,519	302,518
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights			P4Y
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage			25.00%
Compensation expense recognition period (in years)			4 years
Weighted Average Grant-Date Fair Value
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value | $ / shares			$ 34.26	$ 31.48	$ 33.71
Management [Member] | LTIP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Equity grants (in shares)	59,927		91,636
Weighted Average Grant-Date Fair Value
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value | $ / shares			$ 34.21
Management [Member] | Special Time-Based LTIP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Equity grants (in shares)				356,591
Weighted Average Grant-Date Fair Value
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value | $ / shares				$ 36.84
Director [Member] | LTIP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Equity grants (in shares)	47,166		50,159	25,770
Deferred Compensation Arrangement with Individual, Number of Individuals	7
Fair value of awards on grant date | $	$ 250,000		$ 1,800,000	$ 794,000
Measurement Input, Price Volatility [Member] | LTIP and Time-Based LTIP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Minimum			18.00%	20.00%	17.00%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Maximum			24.00%	22.00%	19.00%
Measurement Input, Risk Free Interest Rate [Member] | LTIP and Time-Based LTIP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate, Minimum			2.30%	1.90%	1.30%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate			2.60%	2.60%	1.50%
Minimum | Measurement Input, Expected Term [Member] | LTIP and Time-Based LTIP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term			2 years	2 years	2 years
Maximum | Measurement Input, Expected Term [Member] | LTIP and Time-Based LTIP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term			3 years	3 years	3 years
Share-based Compensation Award, Tranche One [Member] | Special Performance-Based LTIP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage			50.00%
Share-based Compensation Award, Tranche One [Member] | Management [Member] | LTIP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage	50.00%
Share-based Compensation Award, Tranche One [Member] | Management [Member] | Special Time-Based LTIP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage				50.00%
Share-based Compensation Award, Tranche Two [Member] | Management [Member] | LTIP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage	50.00%
Share-based Compensation Award, Tranche Two [Member] | Management [Member] | Special Time-Based LTIP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage				50.00%
Subsequent Event [Member] | Management [Member] | Time-Based LTIP Units
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Equity grants (in shares)		471,598
Fair value of awards on grant date | $		$ 18,300,000

Share-Based Payments - Performa

Share-Based Payments - Performance-Based LTIP Units (Details) - USD ($)	2 Months Ended	12 Months Ended
	Feb. 25, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity grants (in shares)		478,411	567,106	605,072
Performance Shares [Member] | Share-based Compensation Award, Tranche One [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage		50.00%
Performance Shares [Member] | Share-based Compensation Award, Tranche One [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage		50.00%
Performance Shares and Special Performance-Based LTIP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity grants (in shares)		478,411
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		3 years
Fair value of awards on grant date		$ 9,300,000	$ 21,100,000	$ 9,700,000
Weighted Average Grant-Date Fair Value
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value		$ 19.49
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period		(18,054)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value		$ 18
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number		2,117,935	1,657,578
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value		$ 18.55	$ 18.27
Formation Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity grants (in shares)			93,784
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		10 years
Fair value of awards on grant date			$ 725,000	$ 23,700,000
Weighted Average Grant-Date Fair Value
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period		(9,702)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value		$ 8.55
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number		2,484,946	2,655,394
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value		$ 8.81	$ 8.81
Formation Awards [Member] | Share-based Compensation Award, Tranche One [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage		25.00%
Formation Awards [Member] | Share-based Compensation Award, Tranche One [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage		0.00%
Special Performance-Based LTIP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity grants (in shares)			511,555
Special Performance-Based LTIP Units [Member] | Share-based Compensation Award, Tranche One [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage		50.00%
Special Performance-Based LTIP Units [Member] | Special Performance-Based LTIP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage		50.00%
Employee Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Maximum Value of Share Per Employee		$ 25,000
Measurement Input, Price Volatility [Member] | Performance Shares and Special Performance-Based LTIP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Minimum		19.00%	19.90%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Maximum		23.00%	26.00%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate				2.30%
Measurement Input, Price Volatility [Member] | Formation Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Minimum			27.00%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Maximum			29.00%
Measurement Input, Price Volatility [Member] | Employee Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Minimum		18.00%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Maximum		28.00%
Weighted Average Grant-Date Fair Value
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate, Minimum		2.20%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate, Maximum		2.40%
Measurement Input, Expected Dividend Rate [Member] | Formation Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate				2.30%
Measurement Input, Expected Dividend Rate [Member] | Employee Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate			2.50%
Measurement Input, Risk Free Interest Rate [Member] | Performance Shares and Special Performance-Based LTIP Units [Member]
Weighted Average Grant-Date Fair Value
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate, Minimum		2.30%	2.30%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate, Maximum		2.60%	3.00%
Measurement Input, Risk Free Interest Rate [Member] | Formation Awards [Member]
Weighted Average Grant-Date Fair Value
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate, Minimum			2.80%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate, Maximum			3.00%
Measurement Input, Expected Term [Member] | Formation Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term			7 years	7 years
Measurement Input, Expected Term [Member] | Employee Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term		6 years	6 years
Minimum | Measurement Input, Expected Dividend Rate [Member] | Performance Shares and Special Performance-Based LTIP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate		2.30%	2.50%
Minimum | Measurement Input, Expected Dividend Rate [Member] | Formation Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate			2.50%
Minimum | Measurement Input, Expected Dividend Rate [Member] | Employee Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate		2.60%
Maximum | Measurement Input, Expected Dividend Rate [Member] | Performance Shares and Special Performance-Based LTIP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate		2.50%	2.70%
Maximum | Measurement Input, Expected Dividend Rate [Member] | Formation Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate			2.70%
Maximum | Measurement Input, Expected Dividend Rate [Member] | Employee Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate		3.50%
Management [Member] | Subsequent Event [Member] | Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity grants (in shares)	593,100
Fair value of awards on grant date	$ 11,100,000

Share-Based Payments - Employee

Share-Based Payments - Employee Stock Purchase Plan (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Stock Issued During Period, Shares, Employee Stock Purchase Plans	47,000	20,000
Proceeds from common stock issued pursuant to ESPP	$ 1,457,000	$ 597,000	$ 0
Employee Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Percentage of Outstanding Stock Maximum	0.10%
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized	206,600
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	2,100,000
Share-based Compensation Arrangement by Share-based Payment Award, Discount from Market Price, Purchase Date	15.00%
Stock Issued During Period, Shares, Employee Stock Purchase Plans	47,022	20,178
Proceeds from common stock issued pursuant to ESPP	$ 1,500,000	$ 597,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	2,000,000
Measurement Input, Price Volatility [Member] | Employee Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Minimum	18.00%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Maximum		21.00%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate, Minimum	2.20%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate		2.00%
Measurement Input, Expected Dividend Rate [Member] | Employee Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate		2.50%
Measurement Input, Expected Term [Member] | Employee Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term	6 years	6 years
Minimum [Member] | Measurement Input, Expected Dividend Rate [Member] | Employee Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate	2.60%
Maximum | Measurement Input, Expected Dividend Rate [Member] | Employee Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate	3.50%

Share-Based Payments - Summary

Share-Based Payments - Summary of Share-Based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation related to Formation Transaction and special equity awards	$ 42,162	$ 36,030	$ 29,251
Allocated Share-based Compensation Expense, Before Capitalization	67,799	56,016	34,160
Less amount capitalized	(2,526)	(3,341)	(467)
Share-based compensation expense	65,273	52,675	33,693
Total unrecognized compensation expense	$ 77,400
Compensation expense recognition period (in years)	2 years 2 months 12 days
Defined Contribution Plan, Cost	$ 2,000	1,800	3,600
Time-Based LTIP Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense	11,386	10,095	2,211
Performance-Based LTIP Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense	$ 8,716	5,271	1,172
Compensation expense recognition period (in years)	4 years
Long-Term Incentive Partnership Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense	$ 1,000	794	0
Other Equity Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense	4,535	3,826	1,526
Share-based compensation expense - other
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense	25,637	19,986	4,909
Formation Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense	5,734	5,606	5,169
OP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense	29,826	29,455	21,467
LTIP Units Related to Formation Transaction And Other [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense	456	277	2,615
Special Performance-Based LTIP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense	$ 2,843	323	0
Compensation expense recognition period (in years)	5 years
Special Time-Based LTIP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense	$ 3,303	369	0
Compensation expense recognition period (in years)	5 years
Share-based compensation related to Formation Transaction
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation related to Formation Transaction and special equity awards	$ 42,162	$ 36,030	$ 29,251

Transaction and Other Costs T_3

Transaction and Other Costs Transaction and Other Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jul. 18, 2017
Transaction and other costs	$ 23,235	$ 27,706	$ 127,739
Business Acquisition, Transaction Costs	4,700
JBG Companies [Member]
Business Acquisition, Transaction Costs				$ 40,800
Investment Banking Fees Paid			33,600
Legal Fees			13,900
Professional Fees			10,800
Relocation Of Corporate Headquarters
Transaction and other costs	10,900	0	0
Demolition Costs
Transaction and other costs	5,432	0	0
Formation Transaction And Integration Costs | F1RST Residences and JBG Companies [Member]
Transaction and other costs	5,252
Formation Transaction And Integration Costs | JBG Companies [Member]
Transaction and other costs		15,907	127,739
Completed, potential and pursued transaction expenses
Transaction and other costs	651	9,008	0
Other Restructuring
Transaction and other costs	$ 1,000	$ 2,791	$ 0

Interest Expense Interest Exp_3

Interest Expense Interest Expense (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Interest expense	$ 79,234,000	$ 91,651,000	$ 69,178,000
Amortization of deferred financing costs	3,217,000	4,661,000	3,011,000
Net unrealized loss (gain) on derivative financial instruments not designated as cash flow hedges	50,000	(926,000)	(1,348,000)
Derivative, Gain (Loss) on Derivative, Net	0	(135,000)	27,000
Capitalized interest	(29,806,000)	(20,804,000)	(12,727,000)
Interest Expense	$ 52,695,000	$ 74,447,000	$ 58,141,000

Shareholders' Equity and Earn_2

Shareholders' Equity and Earnings Per Common Share Narrative (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	1 Months Ended	12 Months Ended
	Apr. 30, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Apr. 15, 2019
Earnings Per Share [Abstract]
Common Stock, Shares, Issued		134,148	120,937		11,500
Excess Stock, Shares Issued					1,500
Shares Issued, Price Per Share					$ 42
Proceeds from the issuance of common stock, net of issuance costs	$ 472,800	$ 472,780	$ 0	$ 0

Shareholders' Equity and Earn_3

Shareholders' Equity and Earnings Per Common Share Schedule of Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Earnings Per Share [Abstract]
Net income (loss)									$ 74,144	$ 46,613	$ (79,084)
Net (income) loss attributable to redeemable noncontrolling interests									(8,573)	(6,710)	7,328
Net loss attributable to noncontrolling interests									0	21	3
Net income (loss) attributable to common shareholders									(65,571)	(39,924)	71,753
Distributions to participating securities									(2,489)	(2,599)	(1,655)
Net income (loss) available to common shareholders — basic and diluted	$ 34,390	$ 9,360	$ (3,040)	$ 24,861	$ 710	$ 22,830	$ 20,574	$ (4,190)	$ 63,082	$ 37,325	$ (73,408)
Weighted average number of common shares outstanding — basic and diluted									130,687	119,176	105,359
Earnings (loss) per common share:
Earnings Per Share, Basic	$ 0.25	$ 0.06	$ (0.03)	$ 0.20	$ (0.01)	$ 0.19	$ 0.17	$ (0.04)	$ 0.48	$ 0.31	$ (0.70)
Earnings Per Share, Diluted	$ 0.25	$ 0.06	$ (0.03)	$ 0.20	$ (0.01)	$ 0.19	$ 0.17	$ (0.04)	$ 0.48	$ 0.31	$ (0.70)

Shareholders' Equity and Earn_4

Shareholders' Equity and Earnings Per Common Share Antidilutive Securities Excluded (Details) - shares shares in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	4.7	3.9	3.3

Fair Value Measurements - Narra

Fair Value Measurements - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Net unrealized gain (loss) on derivative designated as cash flow hedge	$ (17,700,000)	$ 8,300,000
Loss expected to be reclassified into interest expense within the next 12 months	5,500,000
Net unrealized loss (gain) on derivative financial instruments not designated as cash flow hedges	50,000	$ (926,000)	$ (1,348,000)
Operating Lease, Impairment Loss	$ 10,200,000

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis (Details) - Interest rate swap and caps - Recurring - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Other Assets, Net | Designated as Hedging Instrument
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Classified as assets in Other assets, net		$ 7,913
Other Assets, Net | Designated as Hedging Instrument | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Classified as assets in Other assets, net		0
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		7,913
Other Assets, Net | Designated as Hedging Instrument | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Classified as assets in Other assets, net		0
Other Assets, Net | Not Designated as Hedging Instrument
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Classified as assets in Other assets, net		2,470
Other Assets, Net | Not Designated as Hedging Instrument | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Classified as assets in Other assets, net		0
Other Assets, Net | Not Designated as Hedging Instrument | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Classified as assets in Other assets, net		2,470
Other Assets, Net | Not Designated as Hedging Instrument | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Classified as assets in Other assets, net		0
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	$ 17,440	1,723
Other Liabilities, Net | Designated as Hedging Instrument | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Classified as liabilities in Other liabilities, net	0	0
Other Liabilities, Net | Designated as Hedging Instrument | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Classified as liabilities in Other liabilities, net	17,440	1,723
Other Liabilities, Net | Designated as Hedging Instrument | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Classified as liabilities in Other liabilities, net	$ 0	$ 0

Fair Value Measurements - Finan

Fair Value Measurements - Financial Assets and Liabilities Not Measured at Fair Value (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Mortgages payable | Carrying Amount
Financial liabilities:
Financial liabilities	$ 1,127,848	$ 1,844,652
Mortgages payable | Fair Value
Financial liabilities:
Financial liabilities	1,162,890	1,870,078
Revolving Credit Facility [Member] | Carrying Amount
Financial liabilities:
Financial liabilities	200,000	0
Revolving Credit Facility [Member] | Fair Value
Financial liabilities:
Financial liabilities	200,177	0
Unsecured term loans | Carrying Amount
Financial liabilities:
Financial liabilities	300,000	300,000
Unsecured term loans | Fair Value
Financial liabilities:
Financial liabilities	$ 300,607	$ 300,727

Segment Information - Narrative

Segment Information - Narrative (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)segment	Dec. 31, 2018USD ($)segment
Segment Reporting Information [Line Items]
Number of reportable segments | segment	3	3
Other assets, net	$ 253,687	$ 264,994
Third-Party Real Estate Services Segment
Segment Reporting Information [Line Items]
Other assets, net	$ 31,500	$ 38,600

Segment Information - Summary o

Segment Information - Summary of Third-party Asset Management and Real Estate Services (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Third-party real estate services revenue, excluding reimbursements	$ 65,452	$ 59,684	$ 36,329
Reimbursement Revenue from Third Parties	55,434	39,015	26,907
Revenue from Contract with Customer, Including Reimbursements	120,886	98,699	63,236
Property management fees
Third-party real estate services revenue, excluding reimbursements	22,437	24,831	16,022
Asset management fees
Third-party real estate services revenue, excluding reimbursements	14,045	14,910	10,083
Leasing fees
Third-party real estate services revenue, excluding reimbursements	7,377	6,658	3,639
Development fees
Third-party real estate services revenue, excluding reimbursements	15,655	7,592	3,653
Construction management fees
Third-party real estate services revenue, excluding reimbursements	1,669	2,892	2,220
Other service revenue
Third-party real estate services revenue, excluding reimbursements	$ 4,269	$ 2,801	$ 712

Segment Information - Schedule

Segment Information - Schedule of Reconciliation of Net Income Attributable to Parent (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Dec. 31, 2018	Jun. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Business Acquisition [Line Items]
Net income (loss) attributable to common shareholders			$ 65,571	$ 39,924	$ (71,753)
Depreciation and amortization			191,580	211,436	161,659
Corporate and other			46,822	33,728	39,350
Third-party real estate services			113,495	89,826	51,919
Share-based compensation related to Formation Transaction and special equity awards			42,162	36,030	29,251
Transaction and other costs	$ 15,600		23,235	27,706	127,739
Interest expense			52,695	74,447	58,141
Loss on extinguishment of debt		$ 4,500	5,805	5,153	701
Gain (reduction of gain) on bargain purchase		$ (7,600)	0	(7,606)	24,376
Income tax benefit			(1,302)	(738)	(9,912)
Net (income) loss attributable to redeemable noncontrolling interests			8,573	6,710	(7,328)
Third-party real estate services, including reimbursements			120,886	98,699	63,236
Other Income, Excluding Parking Income			7,638	6,358
Income (loss) from unconsolidated real estate ventures, net			(1,395)	39,409	(4,143)
Interest and other income, net			5,385	15,168	1,788
Gain on sale of real estate			104,991	52,183	0
Net loss attributable to noncontrolling interests			0	21	3
Consolidated NOI			311,131	319,990	289,340
Parking Income			$ 26,000	$ 25,700	$ 23,100

Segment Information - Summary_2

Segment Information - Summary of NOI by Segment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Operating Leases, Income Statement, Lease Revenue		$ 513,447	$ 451,541
Other property operating income			23,069
Total rental revenue			474,610
Direct Costs of Leased and Rented Property or Equipment	$ 137,622	148,081	118,836
Real estate taxes	70,493	71,054	66,434
Total rental expense			185,270
Consolidated NOI			289,340
Operating Segments
Segment Reporting Information [Line Items]
Operating Leases, Income Statement, Lease Revenue	493,273	513,447
Other property operating income	25,973	25,678
Total rental revenue	519,246	539,125
Direct Costs of Leased and Rented Property or Equipment	137,622	148,081
Real estate taxes	70,493	71,054
Total rental expense	208,115	219,135
Consolidated NOI	311,131	319,990
Operating Segments | Commercial Segment [Member]
Segment Reporting Information [Line Items]
Operating Leases, Income Statement, Lease Revenue	383,311	404,826	361,121
Other property operating income	25,593	25,216	22,776
Total rental revenue	408,904	430,042	383,897
Direct Costs of Leased and Rented Property or Equipment	113,177	118,288	97,701
Real estate taxes	50,115	53,324	50,546
Total rental expense	163,292	171,612	148,247
Consolidated NOI	245,612	258,430	235,650
Operating Segments | Multifamily
Segment Reporting Information [Line Items]
Operating Leases, Income Statement, Lease Revenue	116,330	108,989	91,294
Other property operating income	380	368	275
Total rental revenue	116,710	109,357	91,569
Direct Costs of Leased and Rented Property or Equipment	35,236	31,502	24,623
Real estate taxes	15,021	14,280	11,030
Total rental expense	50,257	45,782	35,653
Consolidated NOI	66,453	63,575	55,916
Operating Segments | Other
Segment Reporting Information [Line Items]
Operating Leases, Income Statement, Lease Revenue	(6,368)	(368)	(874)
Other property operating income	0	94	18
Total rental revenue	(6,368)	(274)	(856)
Direct Costs of Leased and Rented Property or Equipment	(10,791)	(1,709)	(3,488)
Real estate taxes	5,357	3,450	4,858
Total rental expense	(5,434)	1,741	1,370
Consolidated NOI	$ (934)	$ (2,015)	$ (2,226)

Segment Information - Summary_3

Segment Information - Summary of Certain Balance Sheet Data by Segment (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Real estate, at cost	$ 5,775,519	$ 5,792,734
Investments in and advances to unconsolidated real estate ventures	543,026	322,878
Total assets (1)	5,986,251	5,997,285
Operating Segments | Commercial Segment [Member]
Segment Reporting Information [Line Items]
Real estate, at cost	3,415,294	3,634,472
Investments in and advances to unconsolidated real estate ventures	396,199	177,173
Total assets (1)	3,361,122	3,707,255
Operating Segments | Multifamily
Segment Reporting Information [Line Items]
Real estate, at cost	1,998,297	1,656,974
Investments in and advances to unconsolidated real estate ventures	107,882	109,232
Total assets (1)	1,682,872	1,528,177
Operating Segments | Other
Segment Reporting Information [Line Items]
Real estate, at cost	361,928	501,288
Investments in and advances to unconsolidated real estate ventures	38,945	36,473
Total assets (1)	$ 942,257	$ 761,853

Commitments and Contingencies -

Commitments and Contingencies - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Real Estate Properties [Line Items]
General liability insurance limit	$ 200,000,000
Property and rental value insurance coverage limit	2,000,000,000
Terrorist acts insurance coverage limit	2,000,000,000
Purchase obligation	196,900,000
Environmental liabilities	17,898,000	$ 17,898,000
Additional capital funding committed amount	57,700,000
Consolidated Properties
Real Estate Properties [Line Items]
Purchase obligation	160,100,000
Principal payment guarantees	8,300,000
Unconsolidated Properties
Real Estate Properties [Line Items]
Purchase obligation	$ 36,800,000
Minimum
Real Estate Properties [Line Items]
Commitment amortization period	2 years
Maximum
Real Estate Properties [Line Items]
Commitment amortization period	3 years

Transactions with Vornado and_2

Transactions with Vornado and Related Parties (Details)	Jul. 18, 2017USD ($)	Jul. 17, 2017USD ($)	Jun. 30, 2016USD ($)ft²	Aug. 31, 2014USD ($)ft²	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Related Party Transaction [Line Items]
Borrowings under revolving credit facility					$ 200,000,000	$ 35,000,000	$ 115,751,000
Qualified Affordable Housing Project Investments, Total Capital Commitments					104,800,000
Corporate and other					46,822,000	33,728,000	39,350,000
Affiliated Entity [Member] | Washington Housing Initiative [Member]
Related Party Transaction [Line Items]
Qualified Affordable Housing Project Investments, Commitment					10,200,000
Affiliated Entity [Member] | Legacy JBG Funds [Member]
Related Party Transaction [Line Items]
Corporate and other					5,000,000	4,900,000	2,200,000
Affiliated Entity [Member] | Separation and Combination transaction | Vornado Realty Trust [Member]
Related Party Transaction [Line Items]
Expenses from related parties					3,600,000	2,200,000
Revenue from related parties					2,000,000	2,100,000	779,000
Affiliated Entity [Member] | Supervisory Services of Properties [Member] | BMS
Related Party Transaction [Line Items]
Related party transaction amount					21,800,000	20,900,000	13,600,000
Affiliated Entity [Member] | Allocations of Centralized Corporate Costs [Member] | Vornado Realty Trust [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Selling, General and Administrative Expenses from Transactions with Related Party							13,000,000
Affiliated Entity [Member] | Fees from Legacy JBG Funds and Washington Housing Initiative [Member] | Legacy JBG Funds and Washington Housing Initiative [Member]
Related Party Transaction [Line Items]
Third-party real estate services, including reimbursements					36,500,000
Accounts Receivable, Related Parties					$ 6,200,000
Affiliated Entity [Member] | Fees from Legacy JBG Funds | Legacy JBG Funds [Member]
Related Party Transaction [Line Items]
Third-party real estate services, including reimbursements						33,800,000	19,900,000
Accounts Receivable, Related Parties						$ 3,600,000
Director [Member] | Consulting Agreement [Member]
Related Party Transaction [Line Items]
Expenses from related parties							16,400,000
Related Party Transaction, Monthly Transaction Amount		$ 169,400
Related Party Transaction, Initial Potential Service Period		24 years
Note Agreement for Development of The Bartlett [Member] | Affiliated Entity [Member] | Financing Transactions [Member] | Vornado Realty Trust [Member]
Related Party Transaction [Line Items]
Debt Instrument, Face Amount	$ 170,000,000
Interest Expense, Related Party							4,100,000
Financing of the Universal Buildings [Member]
Related Party Transaction [Line Items]
Debt Instrument, Face Amount				$ 185,000,000
Financing of the Universal Buildings [Member] | Affiliated Entity [Member] | Financing Transactions [Member] | Vornado Realty Trust [Member]
Related Party Transaction [Line Items]
Origination of Notes Receivable from Related Parties				$ 86,000,000
Interest Income, Related Party							1,800,000
Mortgage loan secured by Bowen Building [Member] | Affiliated Entity [Member] | Vornado Realty Trust [Member]
Related Party Transaction [Line Items]
Interest Expense, Related Party							$ 1,300,000
Repayments of Secured Debt			$ 115,000,000
Debt Instrument, Increase, Accrued Interest			608,000
Borrowings under revolving credit facility			$ 115,600,000
Universal Buildings, Washington DC [Member]
Related Party Transaction [Line Items]
Area of real estate property (in square feet) | ft²			231,000	687,000
London Interbank Offered Rate (LIBOR) [Member] | Financing of the Universal Buildings [Member] | Affiliated Entity [Member] | Financing Transactions [Member] | Vornado Realty Trust [Member]
Related Party Transaction [Line Items]
Debt Instrument, Basis Spread on Variable Rate				2.90%
JBG Companies [Member]
Related Party Transaction [Line Items]
Business Combination, Consideration Transferred, Liabilities Incurred	$ 4,100,000

Quarterly Information (Details)

Quarterly Information (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenues	$ 164,877	$ 167,077	$ 160,617	$ 155,199	$ 163,255	$ 158,443	$ 159,447	$ 163,037	$ 647,770	$ 644,182	$ 543,013
Net income attributable to common shareholders and noncontrolling interests	38,692	10,532	(3,328)	28,248	994	26,382	24,023	(4,786)	65,571	39,903	(71,756)
Net income (loss) available to common shareholders — basic and diluted	$ 34,390	$ 9,360	$ (3,040)	$ 24,861	$ 710	$ 22,830	$ 20,574	$ (4,190)	$ 63,082	$ 37,325	$ (73,408)
Earnings Per Share, Basic	$ 0.25	$ 0.06	$ (0.03)	$ 0.20	$ (0.01)	$ 0.19	$ 0.17	$ (0.04)	$ 0.48	$ 0.31	$ (0.70)
Earnings Per Share, Diluted	$ 0.25	$ 0.06	$ (0.03)	$ 0.20	$ (0.01)	$ 0.19	$ 0.17	$ (0.04)	$ 0.48	$ 0.31	$ (0.70)
Gain on sale of real estate									$ 104,991	$ 52,183	$ 0
Operating Lease, Impairment Loss									10,200
Transaction and other costs					$ 15,600				23,235	27,706	127,739
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Bargain Purchase, Reduction Of Gain							$ (7,600)		0	(7,606)	24,376
Loss on extinguishment of debt							(4,500)		$ (5,805)	(5,153)	$ (701)
The Warner [Member]
Gain on sale of real estate										32,500
Equity Method Investment, Realized Gain (Loss) on Disposal					20,600					20,600
1233 20th Street and Out-of-Service Portion of Falkland Chance - North [Member]
Gain on sale of real estate					$ 6,400
Commerce Executive/Commerce Metro Land [Member]
Gain on sale of real estate				$ 39,000
1600 K Street [Member]
Gain on sale of real estate		$ 8,100
Vienna Retail and Central Place Tower [Member]
Gain on sale of real estate	$ 57,900
Summit I and II and the Bowen Building [Member]
Gain on sale of real estate							$ 33,400
Investment Building [Member]
Equity Method Investment, Realized Gain (Loss) on Disposal						$ 15,500				$ 15,500
Executive Tower [Member]
Gain on sale of real estate						$ 11,900

Schedule II (Details)

Schedule II (Details) - SEC Schedule, 12-09, Allowance for Doubtful Accounts [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2019	Dec. 31, 2016
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
SEC Schedule, 12-09, Valuation Allowances and Reserves, Amount	$ 0	$ 7,594	$ 6,285	$ 0	$ 4,526
SEC Schedule, 12-09, Valuation Allowances and Reserves, Additions, Charge to Cost and Expense	0	3,298	3,807
SEC Schedule, 12-09, Valuation Allowances and Reserves, Increase (Decrease) Adjustment	0	0	0
SEC Schedule, 12-09, Valuation Allowances and Reserves, Deduction	$ 0	$ 1,989	$ 2,048

Schedule III (Details)

Schedule III (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Jan. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		$ 1,627,848
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		1,250,141
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		2,496,974
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		2,028,404
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		1,240,455
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		4,535,064
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		5,775,519	$ 5,895,953	$ 6,025,797	$ 4,155,391
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		1,119,571	1,086,844	1,011,330	$ 930,769
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Other Acquisition		164,320	38,369	0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Other Addition		469,450	358,976	1,926,404
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Write-down or Reserve, Amount		585,753	527,189	55,998
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation, Depreciation Expense		161,937	151,346	136,559
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation, Investment in Real Estate Sold		129,169	75,832	$ 55,998
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Federal Income Tax Basis Difference		55,900
Gross proceeds from sale of real estate			$ 427,400
RTC - West Land [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		1,398
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		29,956
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		3,798
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		29,956
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		3,798
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		33,754
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		0
Potomac Land Bay H [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		38,369
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		29
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		38,390
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		8
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		38,398
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		0
West Half [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		45,668
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		17,902
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		156,076
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		47,342
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		172,304
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		219,646
965 Florida Avenue [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		14,306
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		120,570
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		134,876
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		134,876
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		0
Atlantic Plumbing C [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		47,678
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		13,952
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		94,669
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		156,299
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		156,299
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		0
1900 Crystal Drive [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		16,811
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		53,187
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		(14,948)
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		55,050
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		55,050
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		281
Capitol Point - North [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		32,730
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		18,587
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		50,829
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		488
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		51,317
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		0
Potomac Yard Land Bay G [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		20,318
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		8,815
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		26,804
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		2,329
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		29,133
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		0
Square 649 [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		15,550
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		6,451
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		(1,657)
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		12,672
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		7,672
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		20,344
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		487
Other Future Development Assets [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		76,771
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		15,286
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		30,549
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		77,185
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		45,421
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		122,606
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		444
Corporation [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		500,000
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		11,925
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		11,925
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		11,925
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		3,788
Metropolitan Park [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		65,259
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		1,326
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		27,963
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		82,898
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		11,650
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		94,548
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		32
Pen Place - Land Parcel [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		104,473
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		55
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		(30,625)
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		61,970
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		11,933
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		73,903
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		9
Metropolitan Park and Pen Place [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		169,732
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		1,381
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		(2,662)
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		144,868
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		23,583
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		168,451
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		41
Universal Buildings, Washington DC [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		69,393
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		143,320
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		26,516
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		68,612
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		170,617
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		239,229
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		59,237
2101 L Street [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		134,290
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		32,815
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		51,642
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		94,247
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		39,768
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		138,936
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		178,704
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		43,962
1730 M Street [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		47,500
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		10,095
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		17,541
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		17,207
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		10,687
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		34,156
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		44,843
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		14,154
1700 M Street [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		34,178
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		46,938
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		(26,130)
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		54,986
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		54,986
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		0
Courthouse Plaza 1 and 2 [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		2,200
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		105,475
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		55,168
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		160,643
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		160,643
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		66,985
2121 Crystal Drive [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		133,960
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		21,503
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		87,329
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		31,234
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		22,361
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		117,705
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		140,066
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		51,920
2345 Crystal Drive [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		23,126
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		93,918
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		47,870
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		23,882
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		141,032
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		164,914
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		59,290
2231 Crystal Drive [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		20,611
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		83,705
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		22,116
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		21,311
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		105,121
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		126,432
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		46,350
1550 Crystal Drive [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		17,988
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		70,525
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		27,967
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		18,175
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		98,305
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		116,480
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		42,082
RTC - West [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		92,846
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		30,326
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		134,108
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		11,160
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		30,425
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		145,169
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		175,594
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		16,791
RTC - West Retail [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		2,897
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		2,894
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		8,480
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		2,894
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		8,480
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		11,374
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		709
2011 Crystal Drive [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		18,940
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		76,921
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		42,909
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		19,257
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		119,513
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		138,770
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		53,009
2451 Crystal Drive [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		16,755
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		68,047
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		27,955
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		12,271
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		100,486
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		112,757
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		42,294
1235 S. Clark Street [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		78,000
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		15,826
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		56,090
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		31,131
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		16,444
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		86,603
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		103,047
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		36,804
241 18th Street S. [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		13,867
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		54,169
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		40,229
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		17,018
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		91,247
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		108,265
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		36,854
251 18th Street S. [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		34,152
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		12,305
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		49,360
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		57,055
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		15,859
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		102,861
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		118,720
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		44,679
1215 S. Clark Street [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		13,636
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		48,380
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		54,977
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		14,149
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		102,844
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		116,993
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		36,644
201 12th Street S. [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		32,728
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		14,766
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		52,750
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		24,350
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		15,257
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		76,609
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		91,866
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		33,639
800 North Glebe Road [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		107,500
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		28,168
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		140,983
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		2,290
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		28,168
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		143,273
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		171,441
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		14,785
2200 Crystal Drive [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		13,104
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		30,050
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		34,931
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		13,565
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		64,520
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		78,085
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		21,773
1225 S. Clark Street [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		11,176
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		43,495
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		24,169
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		11,601
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		67,239
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		78,840
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		28,228
1901 South Bell Street [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		11,669
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		36,918
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		21,205
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		12,117
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		57,675
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		69,792
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		26,461
Crystal City Marriott [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		8,000
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		47,191
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		22,029
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		8,045
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		69,175
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		77,220
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		24,859
2100 Crystal Drive [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		10,287
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		23,590
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		31,845
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		10,686
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		55,036
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		65,722
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		25,709
1800 South Bell Street [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		28,702
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		8,370
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		213
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		36,859
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		37,072
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		3,807
200 12th Street S. [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		16,439
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		8,016
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		30,552
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		19,867
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		8,320
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		50,115
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		58,435
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		22,991
2001 Richmond Highway [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		7,300
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		16,746
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		11,722
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		7,520
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		28,248
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		35,768
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		12,628
Crystal City Shops at 2100 [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		4,059
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		9,309
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		3,664
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		4,049
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		12,983
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		17,032
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		5,712
Crystal Drive Retail [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		20,465
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		3,194
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		55
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		23,604
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		23,659
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		11,315
7200 Wisconsin Avenue [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		34,683
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		92,059
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		10,430
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		34,683
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		102,489
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		137,172
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		9,361
One Democracy Plaza [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		33,628
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		8,494
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		42,122
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		42,122
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		25,817
4749 Bethesda Avenue [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		2,480
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		11,830
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		53
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		2,872
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		11,491
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		14,363
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		599
4747 Bethesda Avenue [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		29,030
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		10,040
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		126,535
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		29,492
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		136,113
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		165,605
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		837
1770 Crystal Drive [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		10,771
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		44,276
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		30,727
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		85,774
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		85,774
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		0
Central District Retail [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		4,194
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		48,807
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		53,001
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		53,001
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		0
Fort Totten Square [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		24,390
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		90,404
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		995
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		24,395
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		91,394
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		115,789
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		9,227
WestEnd25 [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		96,227
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		67,049
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		5,039
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		111,284
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		68,213
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		115,159
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		183,372
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		30,478
F1RST Residences [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		31,064
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		133,256
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		10
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		31,064
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		133,266
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		164,330
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		421
1221 Van Street [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		27,386
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		63,775
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		27,162
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		28,198
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		90,125
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		118,323
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		7,905
North End Retail [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		5,847
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		9,333
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		(301)
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		5,871
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		9,008
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		14,879
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		723
RiverHouse Apartments [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		307,710
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		118,421
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		125,078
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		90,748
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		138,946
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		195,301
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		334,247
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		70,549
The Bartlett [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		41,687
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		225,461
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		41,868
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		225,280
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		267,148
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		21,948
220 20th Street [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		8,434
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		19,340
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		101,416
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		8,761
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		120,429
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		129,190
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		34,674
2221 South Clark Street [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		7,405
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		16,981
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		41,453
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		7,583
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		58,256
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		65,839
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		8,936
Falkland Chase - South & West [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		40,001
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		18,530
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		44,232
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		1,062
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		18,642
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		45,182
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		63,824
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		5,017
Falkland Chase-North [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		0
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		9,810
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		22,706
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		(2,072)
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		8,994
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		21,450
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		30,444
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		2,422
Operating and Held for Sale [Member]
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances		1,627,848
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land		1,419,873
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements		2,498,355
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Cost Capitalized Subsequent to Acquisition, Cost		2,025,742
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount		1,385,323
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount		4,558,647
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross		5,943,970
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation		$ 1,119,612
Metropolitan Park [Member] | Subsequent Event [Member]
Gross proceeds from sale of real estate	$ 155,000

Uncategorized Items - jbgs-1231

Label	Element	Value
Dividends Payable, Common Shareholders	jbgs_DividendsPayableCommonShareholders	$ 30,184,000
Dividends Payable, Common Shareholders	jbgs_DividendsPayableCommonShareholders	39,298,000
Dividends Payable, Common Shareholders	jbgs_DividendsPayableCommonShareholders	26,540,000
Dividends Payable, Redeemable Noncontrolling Interest	jbgs_DividendsPayableRedeemableNoncontrollingInterest	4,557,000
Dividends Payable, Redeemable Noncontrolling Interest	jbgs_DividendsPayableRedeemableNoncontrollingInterest	3,828,000
Dividends Payable, Redeemable Noncontrolling Interest	jbgs_DividendsPayableRedeemableNoncontrollingInterest	$ 5,896,000