First Potomac Realty Trust (FPO) 10-Q 28 Oct 16 2016 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information	9 Months Ended
	Sep. 30, 2016shares
Document And Entity Information [Abstract]
Entity Registrant Name	FIRST POTOMAC REALTY TRUST
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	Q3
Entity Central Index Key	1,254,595
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding	58,314,831

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2016		Dec. 31, 2015
Assets:
Rental property, net	$ 1,079,970		$ 1,130,266
Assets held-for-sale	0		90,674
Cash and cash equivalents	14,767		13,527
Escrows and reserves	931		2,514
Accounts and other receivables, net of allowance for doubtful accounts of $1,203 and $876, respectively	6,750		9,868
Accrued straight-line rents, net of allowance for doubtful accounts of $449 and $105, respectively	40,975		36,888
Notes receivable	0		34,000
Investment in affiliates	49,109		48,223
Deferred costs, net	44,702		36,537
Prepaid expenses and other assets	6,755		6,950
Intangible assets, net	26,711		32,959
Total assets	1,270,670	[1]	1,442,406
Liabilities:
Mortgage loans, net	309,116		307,769
Unsecured term loan, net	299,374		299,404
Unsecured revolving credit facility, net	130,353		116,865
Disposal Group, Including Discontinued Operation, Liabilities	0		1,513
Accounts payable and other liabilities	44,373		47,972
Accrued interest	1,512		1,603
Rents received in advance	7,907		6,003
Tenant security deposits	5,183		4,982
Deferred market rent, net	1,874		2,154
Total liabilities	799,692		788,265
Noncontrolling interests in the Operating Partnership	26,155		28,813
Equity:
Common shares, $0.001 par value per share, 150,000 shares authorized; 58,315 and 57,718 shares issued and outstanding, respectively	58		58
Additional paid-in capital	915,413		907,220
Noncontrolling interests in a consolidated partnership	0		800
Accumulated other comprehensive loss	(1,928)		(2,360)
Dividends in excess of accumulated earnings	(468,720)		(440,390)
Total equity	444,823		625,328
Total liabilities, noncontrolling interests and equity	1,270,670		1,442,406
Series A Preferred Shares
Equity:
7.750% Series A Preferred Shares, $25 per share liquidation preference, 0 and 6,400 shares issued and outstanding, respectively	$ 0		$ 160,000
[1]	Total assets include our investment in properties that are owned through joint ventures that are not consolidated within our condensed consolidated financial statements. For more information on our unconsolidated investments, including location within our reportable segments, see note 6, Investment in Affiliates. Corporate assets not allocated to any of our reportable segments totaled $18,723 and $42,988 at September 30, 2016 and 2015, respectively.

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Statement of Financial Position [Abstract]
Allowance for doubtful accounts, accounts and other receivables	$ 908	$ 876
Allowance for doubtful accounts, accrued straight-line rents	$ 316	$ 105
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	50,000,000	50,000,000
Series A Preferred Shares liquidation preference	$ 25	$ 25
Series A Preferred Shares, shares issued	600,000	6,400,000
Series A Preferred Shares, shares outstanding	600,000	6,400,000
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	58,129,000	57,718,000
Common stock, shares outstanding	58,129,000	57,718,000

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Revenues:
Rental	$ 32,416	$ 34,828	$ 97,813	$ 104,051
Tenant reimbursements and other	7,756	8,026	23,548	25,690
Total revenues	40,172	42,854	121,361	129,741
Operating expenses:
Property operating	9,500	10,901	29,580	34,676
Real estate taxes and insurance	4,755	4,815	14,891	14,668
General and administrative	4,112	4,605	12,995	15,110
Depreciation and amortization	13,928	16,758	44,075	49,909
Impairment of rental property	0	0	2,772	0
Total operating expenses	32,295	37,079	104,313	114,363
Operating income	7,877	5,775	17,048	15,378
Other expenses (income)
Interest expense	6,414	6,589	19,798	20,222
Interest and other income	(115)	(995)	(2,219)	(5,797)
Equity in earnings of affiliates	(664)	(432)	(1,883)	(1,235)
(Gain) loss on sale of rental property	0	3,384	(1,155)	3,384
Loss on debt extinguishment	0	0	48	0
Total other expenses (income)	5,635	1,778	16,899	9,806
Income from continuing operations	2,242	3,997	149	5,572
Discontinued operations:
Loss from operations	0	0	0	(975)
Loss on debt extinguishment	0	0	0	(489)
Gain on sale of rental property	0	0	0	857
Loss from discontinued operations	0	0	0	(607)
Net income	2,242	3,997	149	4,965
Less: Net (income) loss attributable to noncontrolling interests	(107)	(38)	430	189
Net income attributable to First Potomac Realty Trust	2,135	3,959	579	5,154
Less: Dividends on preferred shares	(11)	(3,100)	(3,053)	(9,300)
Less: Issuance costs of redeemed preferred shares	(517)	0	(5,515)	0
Net income (loss) attributable to common shareholders	$ 1,607	$ 859	$ (7,989)	$ (4,146)
Basic and diluted earnings per common share:
Income (loss) from continuing operations attributable to common shareholders	$ 0.03	$ 0.01	$ (0.14)	$ (0.06)
Loss from discontinued operations attributable to common shareholders	0	0	0	(0.01)
Net income (loss) attributable to common shareholders	$ 0.03	$ 0.01	$ (0.14)	$ (0.07)
Weighted average common shares outstanding:
Basic	57,597	57,961	57,572	58,155
Diluted	57,825	58,045	57,572	58,155

Consolidated Statements of Comp

Consolidated Statements of Comprehensive (Loss) Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Statement of Comprehensive Income [Abstract]
Net income	$ 2,242	$ 3,997	$ 149	$ 4,965
Unrealized gain on derivative instruments	1,112	171	879	560
Unrealized loss on derivative instruments	0	(903)	(427)	(1,620)
Total comprehensive income	3,354	3,265	601	3,905
Net (income) loss attributable to noncontrolling interests	(107)	(38)	430	189
Net (gain) loss from derivative instruments attributable to noncontrolling interests	(48)	31	(20)	45
Comprehensive income attributable to First Potomac Realty Trust	$ 3,199	$ 3,258	$ 1,011	$ 4,139

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Cash flows from operating activities:
Net income	$ 149	$ 4,965
Discontinued operations:
Gain on sale of rental property	0	(857)
Depreciation and amortization	0	1,222
Depreciation and amortization	44,843	50,387
Stock based compensation	1,625	2,337
Bad debt expense	790	525
Amortization of deferred market rent	236	132
Amortization of financing costs and discounts	1,184	1,048
Equity in earnings of affiliates	(1,883)	(1,235)
Distributions from investments in affiliates	997	632
Gain (Loss) on Sale of Properties	1,155	(3,384)
Impairment of rental property	2,772	0
Changes in assets and liabilities:
Escrows and reserves	1,387	1,111
Accounts and other receivables	2,653	1,151
Accrued straight-line rents	(4,725)	(6,781)
Prepaid expenses and other assets	(641)	(868)
Tenant security deposits	(547)	(613)
Accounts payable and accrued expenses	7,433	1,114
Accrued interest	(92)	(125)
Rents received in advance	1,365	(1,952)
Deferred costs	(12,331)	(6,069)
Total adjustments	46,221	37,775
Net cash provided by operating activities	46,370	42,740
Cash flows from investing activities:
Proceeds from sale of rental property	143,159	71,899
Principal payments from note receivable	34,000	29,720
Change In Escrow And Reserves	196	176
Additions to rental property and furniture, fixtures and equipment	(37,313)	(36,832)
Additions to construction in progress	(11,394)	(13,014)
Payments to Acquire Equity Method Investments	0	(405)
Net cash provided by investing activities	128,648	51,544
Cash flows from financing activities:
Financing costs	(315)	(2,236)
Issuance of debt	224,408	180,956
Repayments of debt	210,964	226,155
Dividends to common shareholders	(20,323)	(26,425)
Dividends to preferred shareholders	(4,603)	(9,300)
Payments of Distributions to Affiliates	(727)	(96)
Distributions to noncontrolling interests	(909)	(1,181)
Repurchase of Common Shares	0	(10,180)
Redemption of preferred shares	(160,000)	0
Redemption of operating partnership units	(345)	(134)
Proceeds from stock option exercises	0	19
Net cash used in financing activities	(173,778)	(94,732)
Net increase (decrease) in cash and cash equivalents	1,240	(448)
Cash and cash equivalents, beginning of period	13,527	13,323
Cash and cash equivalents, end of period	$ 14,767	$ 12,875

Consolidated Statements of Cas7

Consolidated Statements of Cash Flows (Parenthetical) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Capitalized interest on indebtedness paid in cash	$ (700)	$ (1,300)
Surrendered common shares to satisfy statutory minimum federal income tax obligations	137	454
Change in redemption value, noncontrolling interest		3,600
Furniture and Fixtures [Member]
Accrued capital expenditure	7,300
Development and Redevelopment [Member]
Accrued capital expenditure	$ 100	$ 2,000

Description of Business

Description of Business	9 Months Ended
	Sep. 30, 2016
Accounting Policies [Abstract]
Description of Business	Description of Business First Potomac Realty Trust (the “Company”) is a leader in the ownership, management, redevelopment and development of office and business park properties in the greater Washington, D.C. region. The Company’s focus is owning and operating properties that the Company believes can benefit from its market knowledge and intensive operational skills with a focus on increasing their profitability and value. The Company’s portfolio primarily contains a mix of multi-tenant and single-tenant office properties and business parks. Office properties are single-story and multi-story buildings that are primarily for office use; and business parks contain buildings with office features combined with some industrial property space. The Company separates its properties into four distinct reporting segments, which the Company refers to as the Washington, D.C., Maryland, Northern Virginia and Southern Virginia reporting segments. References in these unaudited condensed consolidated financial statements to “we,” “our,” “us,” the “Company” or “First Potomac,” refer to the Company and its subsidiaries, on a consolidated basis, unless the context indicates otherwise. We conduct our business through our Operating Partnership. We are the sole general partner of, and, as of September 30, 2016 , owned 95.8% of the common interest in the Operating Partnership. The remaining common interests in the Operating Partnership, which are presented as noncontrolling interests in the Operating Partnership in the accompanying unaudited condensed consolidated financial statements, are limited partnership interests that are owned by unrelated parties. At September 30, 2016 , we wholly owned properties totaling 6.7 million square feet and had a noncontrolling ownership interest in properties totaling an additional 0.9 million square feet through five unconsolidated joint ventures. We also owned land that can support 0.6 million square feet of additional development. Our consolidated properties were 92.8% occupied by 382 tenants at September 30, 2016 . We derive substantially all of our revenue from leases of space within our properties. As of September 30, 2016 , our largest tenant was the U.S. Government, which accounted for 15.7% of our total annualized cash basis rent, and the U.S. Government combined with government contractors accounted for 26.9% of our total annualized cash basis rent as of September 30, 2016 . We operate so as to qualify as a real estate investment trust (“REIT”) for federal income tax purposes.

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2016
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies (a) Principles of Consolidation Our unaudited condensed consolidated financial statements include our accounts and the accounts of our Operating Partnership, which we consider to be a variable interest entity (“VIE”), and the subsidiaries in which we or our Operating Partnership has a controlling interest, which includes First Potomac Management, LLC, a wholly-owned subsidiary that manages the majority of our properties. All intercompany balances and transactions have been eliminated in consolidation. We have condensed or omitted certain information and note disclosures normally included in financial statements presented in accordance with U.S. generally accepted accounting principles (“GAAP”) in the accompanying unaudited condensed consolidated financial statements. We believe the disclosures made are adequate to prevent the information presented from being misleading. However, the unaudited condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and notes thereto included in our annual report on Form 10-K for the year ended December 31, 2015 and as updated from time to time in our other filings with the SEC. In our opinion, the accompanying unaudited condensed consolidated financial statements reflect all adjustments, consisting of normal recurring adjustments and accruals necessary to present fairly our financial position as of September 30, 2016 and the results of our operations, our comprehensive income and our cash flows for the three and nine months ended September 30, 2016 and 2015 . Interim results are not necessarily indicative of full-year performance due, in part, to the timing of transactions and the impact of acquisitions and dispositions throughout the year, as well as the seasonality of certain operating expenses such as utilities expense and snow and ice removal costs. (b) Use of Estimates The preparation of unaudited condensed consolidated financial statements in conformity with GAAP requires our management team to make a number of estimates and assumptions relating to the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the unaudited condensed consolidated financial statements and the reported amounts of revenues and expenses during the period. Estimates include the amount of accounts receivable that may be uncollectible, future cash flows, discount and capitalization rate assumptions used to fair value acquired properties and to test impairment of certain long-lived assets and goodwill, derivative valuations, market lease rates, lease-up periods, leasing and tenant improvement costs used to fair value intangible assets acquired and probability weighted cash flow analysis used to fair value contingent liabilities. Actual results could differ from those estimates. (c) Rental Property Rental property is initially recorded at fair value, when acquired in a business combination, or initial cost when constructed or acquired in an asset purchase. Improvements and replacements are capitalized at cost when they extend the useful life, increase capacity or improve the efficiency of the asset. Repairs and maintenance are charged to expense when incurred. Depreciation and amortization are recorded on a straight-line basis over the estimated useful lives of the assets. The estimated useful lives of our assets, by class, are as follows: Buildings 39 years Building improvements 5 to 20 years Furniture, fixtures and equipment 5 to 15 years Lease related intangible assets The term of the lease Tenant improvements Shorter of the useful life of the asset or the term of the related lease We regularly review market conditions for possible impairment of a property’s carrying value. When circumstances such as adverse market conditions, changes in management’s intended holding period or potential sale to a third party indicate a possible impairment of the carrying value of a property, an impairment analysis is performed. We assess potential impairments based on an estimate of the future undiscounted cash flows (excluding interest charges) expected to result from the property’s use and eventual disposition. This estimate is based on projections of future revenues, expenses, capital improvement costs to maintain the operating capacity, expected holding periods and capitalization rates. These cash flows consider factors such as expected market trends and leasing prospects, as well as the effects of leasing demand, competition and other factors. If impairment exists due to the inability to recover the carrying value of a real estate investment based on forecasted undiscounted cash flows, an impairment loss is recorded to the extent that the carrying value exceeds the estimated fair value of the property. Further, we will record an impairment loss if we expect to dispose of a property in the near term at a price below carrying value. In such an event, we will record an impairment loss based on the difference between a property’s carrying value and its projected sales price less any estimated costs to sell. We will classify a building as held-for-sale in accordance with GAAP in the period in which we have made the decision to dispose of the building, our Board of Trustees or a designated delegate has approved the sale, there is a binding contract pursuant to which the buyer has significant money at risk, or high likelihood a binding agreement to purchase the property will be signed under which the buyer will be required to commit a significant amount of nonrefundable cash, and no significant financing contingencies exist that could cause the transaction not to be completed in a timely manner. We will cease recording depreciation on a building once it has been classified as held-for-sale. We will also determine whether the disposal of a building qualifies as a discontinued operation in accordance with GAAP by assessing whether the disposal of the building, or group of buildings, represents a strategic shift that has, or will have, a major effect on the Company’s operations or financial results. If the building does not qualify as a discontinued operation in accordance with GAAP, we will classify the building’s operating results, together with any impairment charges and any gains or losses on the sale of the building, in continuing operations for all periods presented in our consolidated statements of operations. We will classify the assets and liabilities related to the building as held-for-sale in our consolidated balance sheet for the period the held-for-sale criteria were met. If the building does qualify as a discontinued operation under GAAP, we will classify the building’s operating results, together with any impairment charges and any gains or losses on the sale of the building, in discontinued operations in our consolidated statements of operations for all periods presented and classify the assets and liabilities related to the building as held-for-sale in our consolidated balance sheets for the periods presented. Interest expense is reclassified to discontinued operations only to the extent the disposed or held-for-sale property is secured by specific mortgage debt and the mortgage debt will not be assigned to another property owned by us after the disposition. We recognize the fair value, if sufficient information exists to reasonably estimate the fair value, of any liability for conditional asset retirement obligations when assumed or incurred, which is generally upon acquisition, construction, development or redevelopment and/or through the normal operation of the asset. We capitalize interest costs incurred on qualifying expenditures for real estate assets under development or redevelopment, which include our investments in assets owned through unconsolidated joint ventures that are under development or redevelopment, while being readied for their intended use in accordance with accounting requirements regarding capitalization of interest. We will capitalize interest when qualifying expenditures for the asset have been made, activities necessary to get the asset ready for its intended use are in progress and interest costs are being incurred. Capitalized interest also includes interest associated with expenditures incurred to acquire developable land while development activities are in progress. We also capitalize direct compensation costs of our construction personnel who manage the development and redevelopment projects, but only to the extent the employee’s time can be allocated to a project. Any portion of construction management costs not directly attributable to a specific project are recognized as general and administrative expense in the period incurred. We do not capitalize any other general and administrative costs such as office supplies, office rent expense or an overhead allocation to our development or redevelopment projects. Capitalized compensation costs were immaterial for the three and nine months ended September 30, 2016 and 2015 . Capitalization of interest ends when the asset is substantially complete and ready for its intended use, but no later than one year from completion of major construction activity if the property is not occupied. We place redevelopment and development assets into service at this time and commence depreciation upon the substantial completion of tenant improvements and the recognition of revenue. Capitalized interest is depreciated over the useful life of the underlying assets, commencing when those assets are placed into service. (d) Notes Receivable We provide loans to the owners of real estate properties, which can be collateralized by interest in the real estate property. We record these loans as “Notes receivable” in our consolidated balance sheets. The loans will be recorded net of any discount or issuance costs, which will be amortized over the life of the respective note receivable using the effective interest method. We record interest earned from notes receivable and amortization of any discount costs or issuance costs within “Interest and other income” in our consolidated statements of operations. We will establish a provision for anticipated credit losses associated with our notes receivable when we anticipate that we may be unable to collect any contractually due amounts. This determination is based upon such factors as delinquencies, loss experience, collateral quality and current economic or borrower conditions. Our collectability of our notes receivable may be adversely impacted by the financial stability of the Washington, D.C. region and the ability of the underlying assets to keep current tenants or attract new tenants. Estimated losses are recorded as a charge to earnings to establish an allowance for credit losses that we estimate to be adequate based on these factors. During the second quarter of 2016, we received the full repayment of a mezzanine loan with an outstanding principal balance of $34.0 million . We did not have any notes receivable outstanding at September 30, 2016 . Based on the review of the above criteria, we did not record an allowance for credit losses for our notes receivable during nine months ended September 30, 2015 . (e) Application of New Accounting Standards In January 2016, we adopted Accounting Standards Update No. 2015-01, Simplifying Income Statement Presentation by Eliminating the Concept of Extraordinary Items (“ASU 2015-01”), which eliminates the concept of extraordinary items from GAAP and the requirement that an entity separately report extraordinary items in the income statement. ASU 2015-01 also requires that entities continue to evaluate whether items are unusual in nature or infrequent in occurrence for presentation and disclosure purposes. The adoption of ASU 2015-01 did not have a material impact on our unaudited condensed consolidated financial statements and related disclosures. In January 2016, we adopted ASU No. 2015-02, Amendments to the Consolidation Analysis (“ASU 2015-02”). This standard amends certain guidance applicable to the consolidation of various legal entities, including variable interest entities (“VIE”). In determining the method of accounting for partially owned joint ventures, we evaluate the characteristics of associated entities and determine whether an entity is a VIE and, if so, determine which party is the primary beneficiary by analyzing whether we have both the power to direct the entity's significant economic activities and the obligation to absorb potentially significant losses or receive potentially significant benefits. Significant judgments and assumptions inherent in this analysis include the nature of the entity's operations, the entity's financing and capital structure, and contractual relationship and terms, including consideration of governance and decision making rights. We consolidate a VIE when we have determined that we are the primary beneficiary. We evaluated the application of ASU 2015-02 and concluded that no change was required to our accounting for any of our interests in less than wholly owned joint ventures. We continued to consolidate our joint venture in Storey Park, which was sold on July 25, 2016, as described in note 12(b), Noncontrolling Interests in a Consolidated Partnership , as it continued to meet the definition and certain criteria as a VIE in which we were considered to be the primary beneficiary. Under ASU 2015-02, our Operating Partnership now meets the definition of a VIE, we are the primary beneficiary, and, accordingly, we continue to consolidate the Operating Partnership. Our sole significant asset is our investment in the Operating Partnership and, consequently, substantially all of our assets and liabilities represent assets and liabilities of the Operating Partnership. All of our debt is an obligation of the Operating Partnership and may only be settled with the assets of the Operating Partnership. In January 2016, we adopted Accounting Standards Update No. 2015-03, Simplifying the Presentation of Debt Issuance Costs (“ASU 2015-03”), which requires debt issuance costs to be presented in the balance sheet as a direct deduction from the carrying value of the debt liability. ASU 2015-03 is applied on a retrospective basis, which resulted in the reclassification of our debt issuance costs from previously presented balances. The guidance did not have a material impact on our unaudited condensed consolidated financial statements and related disclosures. In January 2016, we adopted Accounting Standards Update No. 2015-16, Simplifying the Accounting for Measurement-Period Adjustments (“ASU 2015-16”), which eliminates the requirement for an acquirer to retrospectively adjust the financial statements for measurement-period adjustments that occur in periods after the acquisition of a business combination. The acquirer would instead recognize measurement-period adjustments in the reporting period in which the adjustment is identified. The adoption of ASU 2015-16 did not have a material impact on our unaudited condensed consolidated financial statements and related disclosures. In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update No. 2014-09, Revenue from Contracts with Customers (“ASU 2014-09”), which requires an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers and will replace most existing revenue recognition guidance when it becomes effective. In July 2015, the FASB deferred by one year the mandatory effective date of ASU 2014-09 from January 1, 2017 to January 1, 2018. Early adoption is permitted, but not prior to the original effective date of January 1, 2017. ASU 2014-09 permits the use of either the retrospective or cumulative effect transition method. We have begun to evaluate each of the revenue streams under the new model and the pattern of recognition is not expected to change significantly. We have not yet selected a transition method and are evaluating the impact that ASU 2014-09 will have on our consolidated financial statements and related disclosures. In August 2014, the FASB issued Accounting Standards Update No. 2014-15, Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern (“ASU 2014-15”), which requires an entity to evaluate whether conditions or events, in the aggregate, raise substantial doubt about the entity’s ability to continue as a going concern for one year from the date the financial statements are issued or are available to be issued. The guidance will become effective for annual periods ending after December 15, 2016. The adoption of ASU 2014-15 is not expected to have an impact on our consolidated financial statements and related disclosures. In January 2016, the FASB issued Accounting Standards Update No. 2016-01, Recognition and Measurement of Financial Assets and Financial Liabilities (“ASU 2016-01”), which requires, among other things, entities to use the exit price notion when measuring the fair value of financial instruments for disclosure purposes and eliminates the requirement for public business entities to disclose the method(s) and significant assumptions used to estimate the fair value disclosed for financial instruments measured at amortized cost on the balance sheet. ASU 2016-01 is effective for periods beginning after December 15, 2017; early adoption is not permitted. The guidance is not expected to have a material impact on our consolidated financial statements and related disclosures. In February 2016, the FASB issued Accounting Standards Update No. 2016-02, Leases (“ASU 2016-02”), which requires a lessee to record on the balance sheet a right-of-use asset with a corresponding lease liability created by lease terms of more than 12 months. Additional qualitative and quantitative disclosures will also be required. The guidance will become effective for periods beginning after December 15, 2018 and will be applied using a modified retrospective transition method. We are currently evaluating the impact that ASU 2016-02 will have on our consolidated financial statements and related disclosures. In March 2016, the FASB issued Accounting Standards Update No. 2016-09, Improvements to Employee Share-Based Payment Accounting (“ASU 2016-09”) , which is intended to simplify several aspects of the accounting for employee share-based payment transactions, including income tax consequences, classification of awards as either equity or liabilities and classification on the statement of cash flows. The guidance will become effective for periods beginning after December 15, 2016 and early adoption is permitted. ASU 2016-09 permits the use of the cumulative-effect and prospective methods. We did not elect to early adopt the standard, and the standard is not expected to have a material impact on our consolidated financial statements and related disclosures. In August 2016, the FASB issued Accounting Standards Update No. 2016-15, Classification of Certain Cash Receipts and Cash Payments (“ASU 2016-15”) . The guidance addresses eight classification issues related to the statement of cash flows, including debt prepayment or debt extinguishment costs and distributions received from equity-method investees. The guidance will become effective for periods beginning after December 15, 2017 and early adoption is permitted. ASU 2016-15 requires the use of a retrospective transition method to each period presented. If such retrospective transition is impracticable for certain issues, the adoption of ASU 2016-15 for the applicable issues may be applied prospectively as of the earliest date practicable. While we are currently evaluating the impact of this standard and whether we will elect to early adopt the standard, we do not believe this standard will have a material impact on our consolidated financial statements or related disclosures. (f) Reclassifications Certain prior year asset and debt balances have been reclassified to conform to the current year presentation as a result of adopting ASU 2015-03 in January 2016, which requires debt issuance costs to be presented in the balance sheet as a direct deduction from the carrying value of the debt liability and which is applied on a retrospective basis. See note 2(e), Summary of Significant Accounting Policies - Application of New Accounting Standards for more information.

Earnings Per Common Share

Earnings Per Common Share	9 Months Ended
	Sep. 30, 2016
Earnings Per Share [Abstract]
Earnings Per Common Share	Earnings Per Common Share Basic earnings or loss per common share (“EPS”) is calculated by dividing net income or loss attributable to common shareholders by the weighted average common shares outstanding for the periods presented. Diluted EPS is computed after adjusting the basic EPS computation for the effect of dilutive common equivalent shares outstanding during the periods presented, which include stock options and non-vested shares. We apply the two-class method for determining EPS as our outstanding unvested shares with non-forfeitable dividend rights are considered participating securities. Our excess of distributions over earnings related to participating securities is shown as a reduction in total earnings attributable to common shareholders in our computation of EPS. The following table sets forth the computation of our basic and diluted earnings per common share (dollars in thousands, except per share amounts): Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Numerator for basic and diluted earnings per common share: Income from continuing operations $ 2,242 $ 3,997 $ 149 $ 5,572 Loss from discontinued operations — — — (607 ) Net income 2,242 3,997 149 4,965 Less: Net (income) loss from continuing operations attributable to noncontrolling interests (107 ) (38 ) 430 163 Less: Net loss from discontinued operations attributable to noncontrolling interests — — — 26 Net income attributable to First Potomac Realty Trust 2,135 3,959 579 5,154 Less: Dividends on preferred shares (11 ) (3,100 ) (3,053 ) (9,300 ) Less: Issuance costs of redeemed preferred shares (1) (517 ) — (5,515 ) — Net income (loss) attributable to common shareholders 1,607 859 (7,989 ) (4,146 ) Less: Allocation to participating securities (53 ) (69 ) (179 ) (211 ) Net income (loss) attributable to common shareholders $ 1,554 $ 790 $ (8,168 ) $ (4,357 ) Denominator for basic and diluted earnings per common share: Weighted average common shares outstanding: Basic 57,597 57,961 57,572 58,155 Diluted 57,825 58,045 57,572 58,155 Basic and diluted earnings per common share: Income (loss) from continuing operations attributable to common shareholders $ 0.03 $ 0.01 $ (0.14 ) $ (0.06 ) Loss from discontinued operations attributable to common shareholders — — — (0.01 ) Net income (loss) attributable to common shareholders $ 0.03 $ 0.01 $ (0.14 ) $ (0.07 ) (1) Represents the original issuance costs associated with the redemption of 0.6 million and 6.4 million 7.750% Series A Cumulative Redeemable Perpetual Preferred Shares during the three and nine months ended September 30, 2016, respectively. In accordance with GAAP regarding earnings per common share, we did not include the following potential weighted average common shares in our calculation of diluted earnings per common share as they are anti-dilutive for the periods presented (amounts in thousands): Three Months Ended Nine Months Ended 2016 2015 2016 2015 Stock option awards 929 987 976 1,037 Non-vested share awards 479 307 533 374 1,408 1,294 1,509 1,411

Rental Property

Rental Property	9 Months Ended
	Sep. 30, 2016
Real Estate [Abstract]
Rental Property	Rental Property Rental property represents buildings and related improvements, net of accumulated depreciation, and developable land that are wholly owned or owned by an entity in which we have a controlling interest. All of our rental properties are located within the greater Washington, D.C. region. Rental property consists of the following (dollars in thousands): September 30, 2016 December 31, 2015 (1) Land and land improvements $ 284,463 $ 280,149 Buildings and improvements 831,076 793,184 Construction in progress 13,982 97,361 Tenant improvements 191,598 168,946 Furniture, fixtures and equipment 398 410 1,321,517 1,340,050 Less: accumulated depreciation (241,547 ) (209,784 ) $ 1,079,970 $ 1,130,266 (1) Excludes rental property totaling $90.6 million at December 31, 2015 related to the NOVA Non-Core Portfolio (as defined in note 7, Dispositions ), which was classified as held-for-sale at December 31, 2015 and was sold on March 25, 2016 . Development and Redevelopment Activity We will place completed development and redevelopment assets in-service upon the earlier of one year after major construction activity is deemed to be substantially complete or upon occupancy. We construct office buildings and/or business parks on a build-to-suit basis or with the intent to lease upon completion of construction. At September 30, 2016, we owned developable land that can accommodate 0.6 million square feet of additional building space, of which 34 thousand is located in the Washington, D.C. reporting segment, 0.1 million in the Maryland reporting segment, 0.4 million in the Northern Virginia reporting segment and 0.1 million in the Southern Virginia reporting segment. During the third quarter of 2014, we signed a lease for 167,000 square feet at a to-be-constructed building (the “NOVA build-to-suit”) in our Northern Virginia reporting segment on vacant land that we had in our portfolio. We substantially completed construction of the new building in the first quarter of 2016, and we substantially completed the construction of the tenant improvements during the third quarter of 2016. We commenced revenue recognition in August 2016, at which time the building was placed in-service. Our total investment in the newly constructed building, excluding tenant improvements and leasing commission costs, was $34.6 million as of September 30, 2016, which related to the completion of the building and included the original cost basis of the applicable portion of the vacant land of $5.2 million . On August 4, 2011, we formed a joint venture, in which we had a 97% interest, with an affiliate of Perseus Realty, LLC to acquire Storey Park in our Washington, D.C. reporting segment. At the time, the site was leased to Greyhound Lines, Inc. (“Greyhound”), which subsequently relocated its operations. Greyhound’s lease expired on August 31, 2013 , at which time the property was placed into development with the anticipation of developing a mixed-use project on the 1.6 acre site, which could accommodate up to 712,000 square feet. On July 25, 2016 , our consolidated joint venture sold Storey Park for a contractual purchase price of $54.5 million , which generated net proceeds of $52.7 million . In June 2016, we recorded a $2.8 million impairment charge based on the sales price, less estimated selling costs. On January 1, 2016, we ceased capitalizing expenses associated with the development project as we began marketing the property for sale. During the third quarter of 2016 , other than the NOVA build-to-suit, we did no t place in-service any completed development or redevelopment space. At September 30, 2016 , we did not have any completed development or redevelopment space that had yet to be placed in-service.

Notes Receivable

Notes Receivable	9 Months Ended
	Sep. 30, 2016
Receivables [Abstract]
Notes Receivable	Notes Receivable On June 2, 2016, the owners of 950 F Street, NW, a ten-story, 287,000 square-foot office/retail building located in Washington, D.C., prepaid a mezzanine loan that was secured by a portion of the owners’ interest in the property and had an outstanding balance of $34.0 million . The loan required monthly interest-only payments and had a fixed interest rate of 9.75% . The mezzanine loan was scheduled to mature on April 1, 2017 and had been prepayable since December 21, 2015. In addition to the prepayment of the loan's entire principal balance, we received interest through June 24, 2016 and an exit fee upon the loan's prepayment. We recognized $0.2 million of accelerated income in the second quarter of 2016 related to the payment of the exit fee, which is reflected in “Interest and other income” on our consolidated statement of operations for the nine months ended September 30, 2016. We used the proceeds from the prepayment of the note receivable to redeem the remaining 0.6 million 7.750% Series A Cumulative Redeemable Perpetual Preferred Shares (the “7.750% Series A Preferred Shares”) outstanding and to pay down a portion of our unsecured revolving credit facility. On February 24, 2015, the owners of America’s Square, a 461,000 square foot office complex located in Washington, D.C., prepaid a mezzanine loan that had an outstanding balance of $29.7 million . The loan had a fixed-interest rate of 9.0% and was scheduled to mature on May 1, 2016 . We received a yield maintenance payment of $2.4 million with the prepayment of the loan, which is reflected within “Interest and other income” on our consolidated statement of operations for the nine months ended September 30, 2015. We recorded interest income related to our notes receivable of $1.6 million for the nine months ended September 30, 2016 , and $0.8 million and $2.9 million for the three and nine months ended September 30, 2015 , respectively, which is included within “Interest and other income” on our consolidated statements of operations. No interest income related to our notes receivable was recorded for the three months ended September 30, 2016.

Investment in Affiliates

Investment in Affiliates	9 Months Ended
	Sep. 30, 2016
Equity Method Investments and Joint Ventures [Abstract]
Investment in Affiliates	Investment in Affiliates We own an interest in several joint ventures that own properties. We do not control the activities that are most significant to the joint ventures. As a result, the assets, the liabilities and the operating results of these noncontrolled joint ventures are not consolidated within our unaudited condensed consolidated financial statements. Our investments in these joint ventures are recorded as “Investment in affiliates” on our consolidated balance sheets. Our investment in affiliates consisted of the following (dollars in thousands): Reporting Segment Ownership Investment at September 30, 2016 Investment at December 31, 2015 Prosperity Metro Plaza Northern Virginia 51% $ 26,180 $ 24,909 1750 H Street, NW Washington, D.C. 50% 14,661 15,168 Aviation Business Park (1) Maryland 50% 5,890 5,899 Rivers Park I and II (1)(2) Maryland 25% 2,378 2,247 $ 49,109 $ 48,223 (1) As of the date of this filing, the applicable joint ventures have engaged sales brokers to market these properties for sale. We anticipate completing the sales in late 2016 or early 2017; however, we can provide no assurances regarding the timing or pricing of such sales, or that such sales will ultimately occur. (2) Rivers Park I and Rivers Park II are owned through two separate joint ventures. The following table provides a summary of the mortgage debt held by our unconsolidated joint ventures (dollars in thousands): FPO Ownership Effective Interest Rate Maturity Date Principal Balance at September 30, 2016 (1) Principal Balance at December 31, 2015 (1) Rivers Park I and II (2) 25% LIBOR + 1.90% (3) September 2017 $ 28,000 $ 28,000 1750 H Street, NW (4) 50% 3.92% August 2024 32,000 32,000 Prosperity Metro Plaza (5) 51% 3.91% December 2029 50,000 50,000 Weighted Average / Total 3.54% $ 110,000 $ 110,000 (1) Reflects the entire balance of the debt secured by the properties, not our portion of the debt. (2) The loan is repayable in full, without penalty, at any time during the term of the loan. Of the outstanding principal balance, $2.8 million is recourse to us. We believe the fair value of the potential liability to us related to the recourse debt is inconsequential as the likelihood of our need to perform under the debt agreement is remote. (3) At September 30, 2016 , LIBOR was 0.53% . All references to LIBOR in the condensed consolidated financial statements refer to one-month LIBOR. (4) The loan requires interest-only payments with a constant interest rate over the life of the loan. The loan is repayable in full, without penalty, on or after August 1, 2021. (5) The loan requires interest-only payments through December 2024, at which time the loan requires principal and interest payments through its maturity date. The loan is repayable in full without penalty on or after June 1, 2029. The net assets of our unconsolidated joint ventures consisted of the following (dollars in thousands): September 30, 2016 December 31, 2015 Assets: Rental property, net $ 190,600 $ 193,243 Cash and cash equivalents 7,469 5,992 Other assets 18,914 16,490 Total assets 216,983 215,725 Liabilities: Mortgage loans, net (1)(2) 109,347 109,273 Other liabilities 6,404 7,214 Total liabilities 115,752 116,487 Net assets $ 101,231 $ 99,238 (1) Of the total mortgage debt that encumbers our unconsolidated properties, $2.8 million is recourse to us. We believe the fair value of the potential liability to us under this guaranty is inconsequential as the likelihood of our need to perform under the debt agreement is remote. (2) In the first quarter of 2016, we adopted ASU 2015-03, which requires debt issuance costs to be presented on the balance sheet as a direct deduction from the carrying value of the respective debt liability and which is applied on a retrospective basis. Mortgage loans, net at both September 30, 2016 and December 31, 2015 included $0.7 million of unamortized deferred financing costs. Our share of earnings or losses related to our unconsolidated joint ventures is recorded in our consolidated statements of operations as “Equity in earnings of affiliates.” The following table summarizes the results of operations of our unconsolidated joint ventures for the periods presented, which, due to our varying ownership interests in the joint ventures and the varying operations of the joint ventures, may not be reflective of the amounts recorded in our consolidated statements of operations (dollars in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Total revenues $ 6,328 $ 5,975 $ 18,857 $ 18,205 Total operating expenses (1,908 ) (1,866 ) (5,888 ) (5,778 ) Net operating income 4,420 4,109 12,969 12,427 Depreciation and amortization (1,996 ) (2,254 ) (5,967 ) (6,790 ) Interest expense, net (1,000 ) (980 ) (2,990 ) (2,928 ) Net income $ 1,424 $ 875 $ 4,012 $ 2,709 We earn various fees from several of our joint ventures, which include management fees, leasing commissions and construction management fees. We recognize fees only to the extent of the third party ownership interest in our unconsolidated joint ventures. We recognized fees from our unconsolidated joint ventures of $49 thousand and $0.4 million for the three and nine months ended September 30, 2016 , respectively, and $0.2 million and $0.5 million for the three and nine months ended September 30, 2015, respectively, which are reflected within “Tenant reimbursements and other revenues” on our consolidated statements of operations.

Dispositions

Dispositions	9 Months Ended
	Sep. 30, 2016
Discontinued Operations and Disposal Groups [Abstract]
Dispositions	Dispositions We will report a disposed or held-for-sale property or group of properties in discontinued operations only if the disposal represents a strategic shift that has, or will have, a major effect on our operations and financial results. All other disposed properties will have their operating results reflected within continuing operations on our consolidated statements of operations for all periods presented. We have had, and will have, no continuing involvement with any of our disposed properties subsequent to their disposal. The operations of the disposed properties were not subject to any income based taxes. Other than the properties discussed below in this note 7 , Dispositions , we did not dispose of or enter into any agreements to sell any other properties during the three and nine months ended September 30, 2016 and 2015 . (a) Disposed or Held-for-Sale Properties within Continuing Operations The following table is a summary of property dispositions whose operating results are included in continuing operations in our consolidated statements of operations for the periods presented (dollars in thousands): Property Reporting Disposition Date Property Type Square Feet Net Sale Proceeds Storey Park (1) Washington, D.C. 7/25/2016 Land — $ 52,659 NOVA Non-Core Portfolio (2) Northern Virginia 3/25/2016 Various 945,745 90,501 Cedar Hill I and III Northern Virginia 12/23/2015 Office 102,632 25,939 Newington Business Park Center Northern Virginia 12/17/2015 Industrial 255,600 31,409 Rumsey Center Maryland 7/28/2015 Business Park 135,015 14,956 (1) This development site could have supported up to 712,000 rentable square feet. (2) Consists of Van Buren Office Park, Herndon Corporate Center, Windsor at Battlefield, Reston Business Campus, Enterprise Center, Gateway Centre Manassas, Linden Business Center and Prosperity Business Center (collectively, the “NOVA Non-Core Portfolio”). On July 25, 2016 , we sold Storey Park, a development site located in our Washington, D.C reporting segment that was 97% owned by us through a consolidated joint venture, for net proceeds of $52.7 million . We used the proceeds from the sale to prepay, without penalty, the $22.0 million loan encumbering the Storey Park land (the “Storey Park Land Loan”), to make a distribution to our 3% joint venture partner for their allocable share of the joint venture’s net assets and to pay down a portion of the outstanding balance of our unsecured revolving credit facility. At December 31, 2015, the NOVA Non-Core Portfolio met our held-for-sale criteria and, therefore, the assets of the buildings were classified within “Assets held-for-sale” and the liabilities of the buildings, which included one mortgage that was defeased in March 2016, were classified within “Liabilities held-for-sale” on our consolidated balance sheet. The majority of the assets classified within assets held-for-sale as of December 31, 2015 consisted of $25.2 million in land and land improvements, $88.0 million in buildings and building improvements, $14.4 million in tenant improvements and $37.0 million of accumulated depreciation. Assets held-for-sale also consisted of immaterial amounts of accrued straight-line rents, net of allowance for doubtful accounts, deferred costs, net of accumulated amortization, and prepaid expenses and other assets. The following table summarizes the aggregate results of operations for the disposed or held-for-sale properties that are included in continuing operations for the periods presented (dollars in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Revenues $ — $ 5,118 $ 3,366 $ 16,773 Property operating expenses (60 ) (1,730 ) (1,909 ) (6,282 ) Depreciation and amortization — (1,728 ) (114 ) (5,520 ) Interest expense (44 ) (49 ) (436 ) (461 ) Loss on debt extinguishment — — (48 ) — Impairment of rental property (1) — — (2,772 ) — (Loss) income from operations of disposed property (104 ) 1,611 (1,913 ) 4,510 Gain (loss) on sale of rental property (2) — 3,384 (1,155 ) 3,384 Net (loss) income from continuing operations $ (104 ) $ 4,995 $ (3,068 ) $ 7,894 (1) During the second quarter of 2016, we recorded an impairment charge related to Storey Park based on the anticipated sales price less estimated selling costs. The property was sold on July 25, 2016 . (2) During the first quarter of 2016, we recorded a $1.2 million loss on the sale of the NOVA Non-Core Portfolio, and in the third quarter of 2015, we recorded a $3.4 million gain on the sale of Rumsey Center. (b) Discontinued Operations The following table is a summary of property dispositions whose operating results are reflected as discontinued operations in our consolidated statements of operations for the periods presented (dollars in thousands): Reporting Segment Disposition Date Property Type Square Feet Net Sale Proceeds Richmond Portfolio (1) Southern Virginia 3/19/2015 Business Park 827,900 $ 53,768 (1) Consists of Chesterfield Business Center, Hanover Business Center, Park Central, Virginia Technology Center and a three-acre parcel of undeveloped land (collectively, the “Richmond Portfolio”). With the sale of our Richmond Portfolio, we no longer owned any properties in the Richmond, Virginia area and had strategically exited the Richmond market. As such, the operating results of the Richmond Portfolio are reflected within discontinued operations in our consolidated statement of operations for the nine months ended September 30, 2015. No disposed properties qualified as discontinued operations for the three or nine months ended September 30, 2016 or the three months ended September 30, 2015. The following table summarizes the results of operations of properties included in discontinued operations for the nine months ended September 30, 2015 (dollars in thousands): 2015 Revenues $ 877 Loss from operations, before taxes (1) (975 ) Loss on debt extinguishment (489 ) Gain on sale of rental property 857 (1) For the first quarter of 2015, we accelerated $2.0 million of unamortized straight-line rents, deferred rent abatements and leasing commissions related to the sale of the Richmond Portfolio.

Debt

Debt	9 Months Ended
	Sep. 30, 2016
Debt Disclosure [Abstract]
Debt	Debt Our debt consisted of the following (dollars in thousands): September 30, (1) December 31, 2015 (1)(2) Mortgage loans, net, effective interest rates ranging from 4.22% to 6.01%, maturing at various dates through September 2030 (3)(4) $ 309,116 $ 307,769 Unsecured term loan, net, effective interest rates ranging from LIBOR plus 1.45% to LIBOR plus 1.80%, with staggered maturity dates ranging from December 2020 to December 2022 (3) 299,374 299,404 Unsecured revolving credit facility, net, effective interest rate of LIBOR plus 1.50%, maturing December 2019 (3) 130,353 116,865 Total $ 738,843 $ 724,038 (1) In the first quarter of 2016, we adopted ASU 2015-03, which requires debt issuance costs to be presented on the balance sheet as a direct deduction from the carrying value of the respective debt liability and is applied on a retrospective basis. The balances include a total of $6.7 million and $8.0 million of unamortized deferred financing costs at September 30, 2016 and December 31, 2015 , respectively. (2) Excludes $0.2 million of mortgage debt that was classified within “Liabilities held-for-sale” on our consolidated balance sheet at December 31, 2015. See note 7 , Dispositions , for further discussion. (3) At September 30, 2016 , LIBOR was 0.53% . (4) At September 30, 2016, the mortgage loans balance includes two construction loans. At December 31, 2015, the mortgage loans balance includes two construction loans and the Storey Park Land Loan. (a) Mortgage Loans The following table provides a summary of our mortgage debt, which includes two construction loans and a land loan (dollars in thousands): Encumbered Property Contractual Effective Maturity September 30, 2016 December 31, 2015 Storey Park Land Loan (1)(2) LIBOR + 2.50% LIBOR + 2.50% October 2016 $ — $ 22,000 Hillside I and II (3) 5.75% 4.62% December 2016 12,199 12,368 440 First Street, NW Construction Loan (1)(4) LIBOR + 2.50% LIBOR + 2.50% May 2017 32,216 32,216 Redland II and III 4.20% 4.64% November 2017 63,552 64,543 Northern Virginia Construction Loan (1) LIBOR + 1.85% LIBOR + 1.85% September 2019 34,583 9,176 840 First Street, NE 5.72% 6.01% July 2020 35,377 35,888 Battlefield Corporate Center 4.26% 4.40% November 2020 3,397 3,526 1211 Connecticut Avenue, NW 4.22% 4.47% July 2022 28,657 29,110 1401 K Street, NW 4.80% 4.93% June 2023 35,726 36,224 11 Dupont Circle, NW 4.05% 4.22% September 2030 66,780 66,780 Principal balance 4.37% (5) 312,487 311,831 Unamortized fair value adjustments 31 172 Unamortized deferred financing costs (6) (3,402 ) (4,234 ) Total balance, net $ 309,116 $ 307,769 Debt Classified within Liabilities-Held-for-Sale Gateway Centre Manassas Building I (7) 7.35% 5.88% November 2016 — 212 Unamortized fair value adjustments — 1 Total balance, net $ — $ 213 (1) At September 30, 2016 , LIBOR was 0.53% . (2) The Storey Park Land Loan encumbered the Storey Park land and was entered into by our 97% owned consolidated joint venture that owned Storey Park. On July 25, 2016 , our consolidated joint venture sold Storey Park and the Storey Park Land Loan was concurrently repaid with proceeds from the sale. (3) On October 6, 2016 , we prepaid, without penalty, the Hillside I and II loan with a draw on our unsecured revolving credit facility. (4) This construction loan (the “440 First Street, NW Construction Loan”) is collateralized by 440 First Street, NW. In May 2016, we extended the maturity date by one year to May 30, 2017 . We can repay all or a portion of the construction loan, without penalty, at any time during the term of the loan. At September 30, 2016, per the terms of the loan agreement, 50% of the outstanding principal balance and all of the outstanding accrued interest were recourse to us. (5) Represents the weighted average interest rate. (6) In the first quarter of 2016, we adopted ASU 2015-03, which requires debt issuance costs to be presented on the balance sheet as a direct deduction from the carrying value of the respective debt liability and is applied on a retrospective basis. (7) The mortgage loan that encumbered Gateway Centre Manassas, which was included in the NOVA Non-Core Portfolio and sold on March 25, 2016, was classified within “Liabilities held-for-sale” on our December 31, 2015 consolidated balance sheet. In February 2016, we used $0.2 million in available cash to defease the outstanding balance of the mortgage loan. Northern Virginia Construction Loan On September 1, 2015, we entered into a construction loan (the “Northern Virginia Construction Loan”) that is collateralized by the NOVA build-to-suit, which was placed in-service in the third quarter of 2016. The loan has a borrowing capacity of up to $43.7 million , of which we borrowed $34.6 million as of September 30, 2016 . The loan has a variable interest rate of LIBOR plus a spread of 1.85% and matures on September 1, 2019. We can repay all or a portion of the Northern Virginia Construction Loan, without penalty, at any time during the term of the loan. (b) Unsecured Term Loan and Unsecured Revolving Credit Facility On December 4, 2015, we amended, restated and consolidated our unsecured revolving credit facility and our unsecured term loan. The amendments extended the maturity date of the unsecured term loan’s three $100 million tranches to December 2020, June 2021 and December 2022 from October 2018, October 2019 and October 2020, respectively and the maturity date of the unsecured revolving credit facility to December 2019 from October 2017, with two, six-month extensions at our option. As part of the amendments, we reduced the interest rate spreads on our unsecured term loan and our unsecured revolving credit facility, reduced the capitalization rates used to calculate gross asset value in the financial covenants and amended the covenant package to more closely align with our corporate goals. The table below shows the outstanding balances and the interest rates of the three tranches of the $300.0 million unsecured term loan at September 30, 2016 and December 31, 2015 (dollars in thousands): Maturity Date Interest Rate (1) September 30, 2016 December 31, 2015 Tranche A December 2020 LIBOR + 1.45% $ 100,000 $ 100,000 Tranche B June 2021 LIBOR + 1.45% 100,000 100,000 Tranche C December 2022 LIBOR + 1.80% 100,000 100,000 Total 300,000 300,000 Unamortized deferred financing costs (2) (626 ) (596 ) Total, net $ 299,374 $ 299,404 (1) At September 30, 2016 , LIBOR was 0.53% . The interest rate spread is subject to change based on our maximum total indebtedness ratio. For more information, see note 8 (d), Debt – Financial Covenants . (2) In the first quarter of 2016, we adopted ASU 2015-03, which requires debt issuance costs to be presented on the balance sheet as a direct deduction from the carrying value of the respective debt liability and is applied on a retrospective basis. In June 2016, we used $34.0 million of the proceeds from the prepayment of the 950 F Street, NW mezzanine loan to pay down a portion of the outstanding balance of our unsecured revolving credit facility while we gave 30 days’ notice to our preferred shareholders of our intention to redeem the remaining 0.6 million 7.750% Series A Preferred Shares. In July 2016, we borrowed $15.0 million under the unsecured revolving credit facility to fund the redemption of the remaining 0.6 million 7.750% Series A Preferred Shares that we had announced upon the prepayment of the 950 F Street, NW mezzanine loan. During the three months ended September 30, 2016, we borrowed an additional $8.0 million under the unsecured revolving credit facility to fund construction at the NOVA build-to-suit and for general corporate purposes. During the three months ended September 30, 2016, we repaid $37.0 million of the outstanding balance under the unsecured revolving credit facility. Specifically, on July 25, 2016 , we repaid $27.0 million of the outstanding balance under the unsecured revolving credit facility using a portion of the proceeds from the Storey Park sale, and in September 2016, we repaid $10.0 million of the outstanding balance using tenant reimbursements related to the tenant improvements at the NOVA build-to-suit and available cash. For the three and nine months ended September 30, 2016 , our weighted average borrowings under the unsecured revolving credit facility were $143.5 million and $158.4 million , respectively, with a weighted average interest rate of 1.9% for both periods in 2016, compared with weighted average borrowings of $164.2 million and $168.9 million for the three and nine months ended September 30, 2015 , respectively, with a weighted average interest rate of 1.9% for both periods in 2015. Our maximum outstanding borrowings for the three and nine months ended September 30, 2016 were $162.0 million and $204.0 million , respectively, compared with $217.0 million and $218.0 million for the three and nine months ended September 30, 2015 , respectively. At September 30, 2016 , outstanding borrowings under the unsecured revolving credit facility were $133.0 million with a weighted average interest rate of 2.0% . Our outstanding borrowings under the unsecured revolving credit facility do not include $2.6 million of unamortized deferred financing costs that are deducted from the facility’s balance in the September 30, 2016 consolidated balance sheet in accordance with ASU 2015-03, which we adopted in the first quarter of 2016. At September 30, 2016 , LIBOR was 0.53% and the applicable spread on our unsecured revolving credit facility was 150 basis points. In October 2016, we borrowed $11.0 million under our unsecured revolving credit facility and used available cash to prepay, without penalty, the $12.2 million mortgage loan that encumbered Hillside I and II. As of the date of this filing, we had $144.0 million outstanding and $153.9 million available capacity under the unsecured revolving credit facility. We are required to pay a commitment fee at an annual rate of 0.15% of the unused capacity if our usage exceeds 50% of our total capacity under the revolving credit facility, or 0.25% if our usage does not exceed 50%. (c) Interest Rate Swap Agreements At September 30, 2016 , we had nine interest rate swap agreements outstanding that collectively fixed LIBOR, at a weighted average interest rate of 1.4% , on $240.0 million of our variable rate debt. See note 9 , Derivative Instruments , for more information about our interest rate swap agreements. In July 2016, two swap agreements that together fixed LIBOR at a weighted average interest rate of 1.8% on $60.0 million of variable rate debt expired. (d) Financial Covenants The credit agreement governing our unsecured revolving credit facility and unsecured term loan contains various restrictive covenants, including with respect to liens, indebtedness, investments, distributions, mergers and asset sales. The agreement also includes customary events of default, the occurrence of which, following any applicable cure period, would permit the lenders to, among other things, declare the principal, accrued interest and other obligations of our Company under the agreement to be immediately due and payable. Our outstanding corporate debt agreements contain specific financial covenants that may impact future financing decisions made by us or may be impacted by a decline in operations. These covenants relate to our allowable leverage, minimum tangible net worth, fixed charge coverage and other financial metrics. As of September 30, 2016 , we were in compliance with the covenants of our amended, restated and consolidated unsecured revolving credit facility and unsecured term loan, the 440 First Street, NW Construction Loan and the Northern Virginia Construction Loan. Our continued ability to borrow under the unsecured revolving credit facility is subject to compliance with financial and operating covenants, and a failure to comply with any of these covenants could result in a default under the credit facility. These debt agreements also contain cross-default provisions that would be triggered if we were in default under other loans, including mortgage loans, in excess of certain amounts. In the event of a default, the lenders could accelerate the timing of payments under the debt obligations and we may be required to repay such debt with capital from other sources, which may not be available on attractive terms, or at all, which would have a material adverse effect on our liquidity, financial condition, results of operations and ability to make distributions to our shareholders. Our unsecured revolving credit facility and unsecured term loan are subject to interest rate spreads that float based on the quarterly measurement of our maximum consolidated total indebtedness to gross asset value ratio. Based on our leverage ratio at September 30, 2016, the applicable interest rate spreads on the unsecured revolving credit facility and the unsecured term loan will remain unchanged.

Derivative Instruments

Derivative Instruments	9 Months Ended
	Sep. 30, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments	Derivative Instruments We are exposed to certain risks arising from business operations and economic factors. We use derivative financial instruments to manage exposures that arise from business activities in which our future exposure to interest rate fluctuations is unknown. The objective in the use of an interest rate derivative is to add stability to interest expenses and manage exposure to interest rate changes. We do not use derivatives for trading or speculative purposes and we intend to enter into derivative agreements only with counterparties that we believe have a strong credit rating to mitigate the risk of counterparty default or insolvency. No hedging activity can completely insulate us from the risks associated with changes in interest rates. Moreover, interest rate hedging could fail to protect us or adversely affect us because, among other things: • available interest rate hedging may not correspond directly with the interest rate risk for which we seek protection; • the duration of the hedge may not match the duration of the related liability; • the party owing money in the hedging transaction may default on its obligation to pay; and • the credit quality of the party owing money on the hedge may be downgraded to such an extent that it impairs our ability to sell or assign its side of the hedging transaction. We enter into interest rate swap agreements to hedge our exposure on our variable rate debt against fluctuations in prevailing interest rates. The interest rate swap agreements fix LIBOR to a specified interest rate; however, the swap agreements do not affect the contractual spreads associated with each variable debt instrument’s applicable interest rate. At September 30, 2016 , we had nine interest rate swap agreements outstanding that collectively fixed LIBOR, at a weighted average interest rate of 1.4% , on $240.0 million of our variable rate debt. Our interest rate swap agreements are summarized below (dollars in thousands): Maturity Date Notional Amount Interest Rate Contractual Component Fixed LIBOR Interest Rate July 2017 30,000 LIBOR 2.093 % July 2017 30,000 LIBOR 2.093 % July 2017 25,000 LIBOR 1.129 % July 2017 12,500 LIBOR 1.129 % July 2017 50,000 LIBOR 0.955 % July 2018 12,500 LIBOR 1.383 % July 2018 30,000 LIBOR 1.660 % July 2018 25,000 LIBOR 1.394 % July 2018 25,000 LIBOR 1.135 % Total/Weighted Average $ 240,000 1.442 % In July 2016, two swap agreements that together fixed LIBOR at a weighted average interest rate of 1.8% on $60.0 million of variable rate debt expired. Our interest rate swap agreements are designated as cash flow hedges and we record the effective portion of any unrealized gains associated with the change in fair value of the swap agreements within “Accumulated other comprehensive loss” and “Prepaid expenses and other assets” and the effective portion of any unrealized losses within “Accumulated other comprehensive loss” and “Accounts payable and other liabilities” on our consolidated balance sheets. We record our proportionate share of any unrealized gains or losses on our cash flow hedges associated with our unconsolidated joint ventures within “Accumulated other comprehensive loss” and “Investment in affiliates” on our consolidated balance sheets. We record any gains or losses incurred as a result of each interest rate swap agreement’s fixed rate deviating from our respective loan’s contractual rate within “Interest expense” on our consolidated statements of operations. We did not have any material ineffectiveness associated with our cash flow hedges during the nine months ended September 30, 2016 and 2015 . Amounts reported in accumulated other comprehensive loss related to derivatives will be reclassified to “Interest expense” on our consolidated statements of operations as interest payments are made on our variable-rate debt. We reclassified accumulated other comprehensive losses as an increase to interest expense of $0.6 million and $2.3 million for the three and nine months ended September 30, 2016, respectively, and $1.0 million and $3.0 million for the three and nine months ended September 30, 2015, respectively. As of September 30, 2016 , we estimated that $1.6 million of our accumulated other comprehensive loss will be reclassified as an increase to interest expense over the following twelve months.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2016
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements Our application of GAAP outlines a valuation framework and creates a fair value hierarchy, which distinguishes between assumptions based on market data (observable inputs) and a reporting entity’s own assumptions about market data (unobservable inputs). The required disclosures increase the consistency and comparability of fair value measurements and the related disclosures. Fair value is identified, under the standard, as the price that would be received to sell an asset or paid to transfer a liability between willing third parties at the measurement date (an exit price). In accordance with GAAP, certain assets and liabilities must be measured at fair value, and we provide the necessary disclosures that are required for items measured at fair value as outlined in the accounting requirements regarding fair value. Financial assets and liabilities, as well as those non-financial assets and liabilities requiring fair value measurement, are measured using inputs from three levels of the fair value hierarchy. The three levels are as follows: Level 1 - Inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities that we have the ability to access at the measurement date. An active market is defined as a market in which transactions for the assets or liabilities occur with sufficient frequency and volume to provide pricing information on an ongoing basis. Level 2 - Inputs include quoted prices for similar assets and liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active (markets with few transactions), inputs other than quoted prices that are observable for the asset or liability (i.e., interest rates, yield curves, etc.), and inputs derived principally from or corroborated by observable market data correlation or other means (market corroborated inputs). Level 3 - Unobservable inputs, only used to the extent that observable inputs are not available, reflect our assumptions about the pricing of an asset or liability. In accordance with accounting provisions and the fair value hierarchy described above, the following table shows the fair value of our consolidated assets and liabilities that are measured on a non-recurring and recurring basis as of September 30, 2016 and December 31, 2015 (dollars in thousands): Balance at Level 1 Level 2 Level 3 Recurring Measurements: Derivative instrument-swap liabilities $ 2,045 $ — $ 2,045 $ — Balance at Level 1 Level 2 Level 3 Non-recurring Measurements: Impaired real estate assets $ 104,625 $ — $ 90,625 $ 14,000 Recurring Measurements: Derivative instrument-swap liabilities 2,491 — 2,491 — We did not re-measure or complete any transactions involving non-financial assets or non-financial liabilities that are measured at fair value on a recurring basis during the nine months ended September 30, 2016 and 2015 . Also, no transfers into or out of fair value measurement levels for assets or liabilities that are measured on a recurring basis occurred during the nine months ended September 30, 2016 and 2015 . Impairment of Rental Property We regularly review market conditions for possible impairment of a property’s carrying value. When circumstances such as adverse market conditions, changes in management’s intended holding period or potential sale to a third party indicate a possible impairment of a property, an impairment analysis is performed. In March 2016, we sold our NOVA Non-Core Portfolio, which is located in our Northern Virginia reporting segment. Based on the anticipated sales price, less estimated selling costs, we recorded an impairment charge of $26.9 million for the fourth quarter of 2015, and we recorded an additional loss on the sale of $1.2 million in the first quarter of 2016. See note 7 , Dispositions , for more information. Our One Fair Oaks office property, which is located in our Northern Virginia reporting segment, is currently fully leased to CACI International. We expect that CACI International will vacate the property upon their lease expiration in December 2016, and, as a result of the anticipated loss of cash flow and the anticipated challenges of re-leasing the property, we evaluated the recoverability of the property's carry value at December 31, 2015, which coincided with our review of year-end results and assessment of overall market conditions. Based on an analysis of the undiscounted net cash flows from One Fair Oaks, we concluded that the carrying value of the property was not recoverable and recorded an impairment charge of $33.9 million to bring the property to its estimated fair value in the fourth quarter of 2015. We estimated the fair value of the property using a discounted cash flow analysis and comparable sales information. In our analysis, we estimated the future net cash flows from the property using an income-based valuation of the building as vacant. The expected useful life and holding period was based on the age of the property and our current plan for the property as well as experience with similar properties. The capitalization rate was estimated using rates from external market research and comparable market transactions, and the discount rate was estimated using a risk adjusted rate of return. As of the date of this filing, we have engaged sales brokers to market One Fair Oaks for sale. We anticipate completing the sale in late 2016 or early 2017; however, we can provide no assurances regarding the timing or pricing of the sale, or that such sale will ultimately occur. Interest Rate Derivatives At September 30, 2016 , we had hedged $240.0 million of our variable rate debt through nine interest rate swap agreements. See note 9 , Derivative Instruments , for more information about our interest rate swap agreements. The interest rate derivatives are fair valued based on prevailing market yield curves on the measurement date and also incorporate credit valuation adjustments to appropriately reflect both our own nonperformance risk and the respective counterparty’s nonperformance risk in the fair value measurements. In adjusting the fair value of our derivative contracts for the effect of nonperformance risk, we have considered the impact of netting any applicable credit enhancements, such as collateral postings, thresholds, mutual inputs and guarantees. We use a third party to assist in valuing our interest rate swap agreements. A daily “snapshot” of the market is taken to obtain close of business rates. The snapshot includes over 7,500 rates including LIBOR fixings, Eurodollar futures, swap rates, exchange rates, treasuries, etc. This market data is obtained via direct feeds from Bloomberg and Reuters and from Inter-Dealer Brokers. The selected rates are compared to their historical values. Any rate that has changed by more than normal mean and related standard deviation would be considered an outlier and flagged for further investigation. The rates are then compiled through a valuation process that generates daily valuations, which are used to value our interest rate swap agreements. Our interest rate swap derivatives are effective cash flow hedges and the effective portion of the change in fair value is recorded in the equity section of our consolidated balance sheets as “Accumulated other comprehensive loss.” Financial Instruments The carrying amounts of cash equivalents, accounts and other receivables, accounts payable and other liabilities, with the exception of any items listed above, approximate their fair values due to their short-term maturities. We determine the fair value of our notes receivable and debt instruments by discounting future contractual principal and interest payments using prevailing market rates for securities with similar terms and characteristics at the balance sheet date. We deem the fair value measurement of our debt instruments as a Level 2 measurement as we use quoted interest rates for similar debt instruments to value our debt instruments. We used quoted market interest rates for similar notes to value our notes receivable at December 31, 2015, which we considered a Level 2 measurement as we do not believe notes receivable trade in an active market. The carrying amount and estimated fair value of our notes receivable and debt instruments are as follows (dollars in thousands): September 30, 2016 December 31, 2015 Carrying (1) Fair Carrying (1) Fair Financial Assets: Notes receivable (2) $ — $ — $ 34,000 $ 34,000 Financial Liabilities: Mortgage debt (3) $ 312,517 $ 324,145 $ 312,216 $ 298,541 Unsecured term loan 300,000 300,000 300,000 300,000 Unsecured revolving credit facility 133,000 133,000 120,000 120,000 Total $ 745,517 $ 757,145 $ 732,216 $ 718,541 (1) In the first quarter of 2016, we adopted ASU 2015-03, which requires debt issuance costs to be presented in the balance sheet as a direct deduction from the carrying value of the respective debt liability and which is applied on a retrospective basis. The debt balances exclude a combined total of $6.7 million and $8.0 million of unamortized deferred financing costs at September 30, 2016 and December 31, 2015, respectively. (2) The note receivable was prepaid on June 2, 2016 . See note 5 , Notes Receivable , for more information regarding the prepayment of the note receivable. (3) Includes $0.2 million of mortgage debt that was classified within “Liabilities held-for-sale” on our consolidated balance sheet at December 31, 2015. See note 7, Dispositions , for additional information.

Equity

Equity	9 Months Ended
	Sep. 30, 2016
Equity [Abstract]
Equity	Equity In December 2015, our Board of Trustees authorized the redemption of some or all of our 6.4 million outstanding 7.750% Series A Preferred Shares. On January 19, 2016 and April 27, 2016 , we used proceeds from dispositions to redeem 2.2 million shares and 3.6 million shares, respectively, of our 7.750% Series A Preferred Shares at a redemption price of $25.00 per share, plus accrued dividends up to the applicable dates of redemption. On July 6, 2016 , we used proceeds from the repayment of the 950 F Street, NW mezzanine loan to redeem the remaining 0.6 million outstanding shares of our 7.750% Series A Preferred Shares at a redemption price of $25.00 per share, plus accrued dividends up to the date of redemption. Prior to the July 6, 2016 preferred share redemption, we were required to give the preferred shareholders 30 days’ written notice of our intent to redeem our 7.750% Series A Preferred Shares, in whole or in part. During the 30-day period from the date of notification to our preferred shareholders to the redemption of our remaining 0.6 million 7.750% Series A Preferred Shares, the net proceeds from 950 F Street, NW loan prepayment were used to temporarily pay down a portion of the balance of our unsecured revolving credit facility. The 7.750% Series A Preferred Shares (NYSE: FPO-PA) were delisted from trading on the New York Stock Exchange upon redemption of the remaining 0.6 million outstanding shares on July 6, 2016 . In July 2015, our Board of Trustees authorized a share repurchase program that allowed us to acquire up to five million of our common shares of beneficial interest from time to time through July 2016 in open market transactions at prevailing prices or in negotiated private transactions. We were not obligated to acquire any particular amount of common shares and the share repurchase program was subject to suspension by the Board of Trustees at any time. During 2015, we repurchased 924,198 shares at a weighted average share price of $10.99 for a total purchase price of $10.2 million , utilizing proceeds from dispositions. During the nine months ended September 30, 2016, we did not repurchase any common shares under the share repurchase program. We are no longer authorized to repurchase common shares under the previously authorized share repurchase program, which expired at the end of July 2016. On October 24, 2016 , we declared a dividend of $0.10 per common share, equating to an annualized dividend of $0.40 per common share. The dividend will be paid on November 15, 2016 to common shareholders of record as of November 8, 2016 . Dividends on non-vested share awards that are expected to vest are recorded as a reduction of shareholders’ equity and dividends on non-vested share awards that are not expected to vest are recorded as compensation expense. Any adjustments to the vesting estimates are recorded in the current period. For each dividend paid by us on our common shares, the Operating Partnership distributes an equivalent distribution on our common Operating Partnership units. On July 25, 2016 , we declared a dividend of $0.10 per common share, equating to an annualized dividend of $0.40 per common share. The dividend was paid on August 15, 2016 to common shareholders of record as of August 8, 2016 . Our unsecured revolving credit facility and unsecured term loan, the 440 First Street, NW Construction Loan and the Northern Virginia Construction Loan contain certain restrictions that include, among other things, requirements to maintain specified coverage ratios and other financial covenants, which may limit our ability to make distributions to our common and preferred shareholders, except for distributions required to maintain our qualification as a REIT. As a result of the redemption feature of the Operating Partnership units, the noncontrolling interests associated with the Operating Partnership are recorded outside of permanent equity. Our equity and redeemable noncontrolling interests are as follows (dollars in thousands): First Potomac Realty Trust Non-redeemable noncontrolling interests Total Equity Redeemable noncontrolling interests Balance at December 31, 2015 $ 624,528 $ 800 $ 625,328 $ 28,813 Net income (loss) 579 (73 ) 506 (357 ) Changes in ownership, net (155,790 ) — (155,790 ) (1,412 ) Distributions to owners (1) (24,926 ) (727 ) (25,653 ) (909 ) Other comprehensive income, net 432 — 432 20 Balance at September 30, 2016 $ 444,823 $ — $ 444,823 $ 26,155 First Potomac Realty Trust Non-redeemable noncontrolling interests Total Equity Redeemable noncontrolling interests Balance at December 31, 2014 $ 710,007 $ 898 $ 710,905 $ 33,332 Net income (loss) 5,154 (3 ) 5,151 (186 ) Changes in ownership, net 3,289 — 3,289 (1,257 ) Distributions to owners (35,725 ) (96 ) (35,821 ) (1,181 ) Other comprehensive loss, net (1,015 ) — (1,015 ) (45 ) Repurchase of common shares (10,180 ) — (10,180 ) — Balance at September 30, 2015 $ 671,530 $ 799 $ 672,329 $ 30,663 (1) Our 97% owned consolidated joint venture sold Storey Park on July 25, 2016 , at which time all assets and liabilities owned by the joint venture were either sold or settled at the time of disposition and the remaining proceeds from the sale were distributed to the joint venture partners in accordance with the terms of the joint venture agreement. See note 7, Dispositions , and note 12(b), Noncontrolling Interests in a Consolidated Partnership , for more information. A summary of our accumulated other comprehensive loss is as follows (dollars in thousands): 2016 2015 Beginning balance at January 1, $ (2,360 ) $ (3,268 ) Net unrealized gain (loss) on derivative instruments 452 (1,060 ) Net (gain) loss attributable to noncontrolling interests (20 ) 45 Ending balance at September 30, $ (1,928 ) $ (4,283 )

Noncontrolling Interests

Noncontrolling Interests	9 Months Ended
	Sep. 30, 2016
Noncontrolling Interest [Abstract]
Noncontrolling Interests	Noncontrolling Interests (a) Noncontrolling Interests in the Operating Partnership Noncontrolling interests relate to the common interests in the Operating Partnership not owned by us. Interests in the Operating Partnership are owned by limited partners who contributed buildings and other assets to the Operating Partnership in exchange for common Operating Partnership units. Limited partners have the right to tender their units for redemption in exchange for, at our option, our common shares on a one-for-one basis or cash based on the fair value of our common shares at the date of redemption. Unitholders receive a distribution per unit equivalent to the dividend per common share. Differences between amounts paid to redeem noncontrolling interests and their carrying values are charged or credited to equity. As a result of the redemption feature of the Operating Partnership units, the noncontrolling interests are recorded outside of permanent equity. Noncontrolling interests are presented at the greater of their fair value or their cost basis, which is comprised of their fair value at issuance, subsequently adjusted for the noncontrolling interests’ share of net income or losses available to common shareholders, other comprehensive income or losses, distributions received or additional contributions. We account for issuances of common Operating Partnership units individually, which could result in some portion of our noncontrolling interests being carried at fair value with the remainder being carried at historical cost. Based on the closing price of our common shares at September 30, 2016 , the cost to acquire, through cash purchase or issuance of our common shares, all of the outstanding common Operating Partnership units not owned by us was $23.6 million . At September 30, 2016 and December 31, 2015 , we recorded adjustments of $3.2 million and $4.0 million , respectively, to present certain common Operating Partnership units at the greater of their carrying value or redemption value. At September 30, 2016 , 2,577,478 of the total common Operating Partnership units, or 4.2% , were not owned by us. During the nine months ended September 30, 2016 and 2015 , 41,591 and 11,508 common Operating Partnership units, respectively, were redeemed with available cash. No common Operating Partnership units were redeemed for common shares during the nine months ended September 30, 2016 or 2015 . (b) Noncontrolling Interests in a Consolidated Partnership When we are deemed to have a controlling interest in a partially-owned entity, we will consolidate all of the entity’s assets, liabilities and operating results within our condensed consolidated financial statements. The net assets contributed to the consolidated entity by the third party, if any, will be reflected within permanent equity in our consolidated balance sheets to the extent they are not mandatorily redeemable. The amount will be recorded based on the third party’s initial investment in the consolidated entity and will be adjusted to reflect the third party’s share of earnings or losses in the consolidated entity and any distributions received or additional contributions made by the third party. The earnings or losses from the entity attributable to the third party are recorded as a component of “Net (income) loss attributable to noncontrolling interests” on our consolidated statements of operations. On August 4, 2011, we formed a joint venture, in which we had a 97% interest, with an affiliate of Perseus Realty, LLC to acquire Storey Park in our Washington, D.C. reporting segment, which was placed into development in August 2013. Storey Park was sold July 25, 2016 , at which time all assets and liabilities owned by the joint venture were either sold or settled at the time of disposition and the remaining proceeds from the sale were distributed to the joint venture partners in accordance with the terms of the joint venture agreement. See note 7 , Dispositions , for more information.

Share-Based Payments

Share-Based Payments	9 Months Ended
	Sep. 30, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-Based Payments	Share-Based Payments We record costs related to our share-based compensation based on the grant-date fair value calculated in accordance with GAAP. We recognize share-based compensation costs on a straight-line basis over the requisite service period for each award and these costs are recorded within “General and administrative expense” or “Property operating expense” on our consolidated statements of operations based on the employee’s job function. Non-Vested Share Awards We issue non-vested common share awards that either vest over a specific time period that is identified at the time of issuance or vest upon the achievement of specific performance goals that are identified at the time of issuance. We issue new common shares, subject to restrictions, upon each grant of non-vested common share awards. In July 2016, we granted a total of 181,357 non-vested performance-based common shares to our officers. The number of shares that will be earned will be determined no later than February 1, 2019 based upon the achievement of specified market performance goals for the period from February 22, 2016 (the date we announced our 2016 Strategic Plan) through December 31, 2018. Of the shares earned, 50% will vest on February 1, 2019 and the remaining earned shares will vest on February 1, 2020. Any shares that are not earned and do not vest in February 2019 or February 2020 will be forfeited. We recognized compensation expense associated with our non-vested common share awards of $0.6 million and $1.5 million during the three and nine months ended September 30, 2016 , respectively, compared with $0.7 million and $2.0 million during the three and nine months ended September 30, 2015 , respectively. Dividends on all non-vested common share awards are recorded as a reduction of equity. We apply the two-class method for determining EPS as our outstanding non-vested common shares with non-forfeitable dividend rights are considered participating securities. Our excess of dividends over earnings related to participating securities are shown as a reduction in net income or loss attributable to common shareholders in our computation of EPS. A summary of our non-vested common share awards at September 30, 2016 is as follows: Non-vested Common Shares Weighted Average Grant Date Fair Value Non-vested at June 30, 2016 532,069 $ 10.31 Granted 181,357 8.59 Non-vested at September 30, 2016 713,426 $ 9.87 We value our non-vested time-based share awards at the grant date fair value, which is the market price of our common shares. For the performance-based non-vested common share awards granted in July 2016, the Company used a Monte Carlo Simulation (risk-neutral approach) to determine the number of shares that may be issued pursuant to the award as these awards were deemed to have a market condition. The risk-free interest rate assumptions used in the Monte Carlo Simulation were determined based on the zero coupon risk-free rate for the time frame of 0.25 years to 3 years, which ranged from 0.48% to 0.96% , respectively. The volatility used for the Company’s common share price in the Monte Carlo Simulation varied between 24.10% and 26.20% . As of September 30, 2016 , we had $5.5 million of unrecognized compensation cost related to non-vested common shares. We anticipate this cost will be recognized over a weighted-average period of 3.3 years.

Segment Information

Segment Information	9 Months Ended
	Sep. 30, 2015
Segment Reporting [Abstract]
Segment Information	Segment Information Our reportable segments consist of four distinct reporting and operational segments within the greater Washington, D.C. region in which we operate: Washington, D.C., Maryland, Northern Virginia and Southern Virginia. We evaluate the performance of our segments based on the operating results of the properties located within each segment, which excludes large non-recurring gains and losses, gains or losses from sale of rental property, interest expense, general and administrative costs, acquisition costs or any other indirect corporate expense to the segments. In addition, the segments do not have significant non-cash items other than straight-line and deferred market rent amortization reported in their operating results. There are no inter-segment sales or transfers recorded between segments. The results of operations of our four reporting segments for the three and nine months ended September 30, 2016 and 2015 are as follows (dollars in thousands): Three Months Ended September 30, 2016 Washington, D.C. Maryland Northern Virginia Southern Virginia Consolidated Number of buildings 6 34 15 19 74 Square feet 917,453 1,885,786 1,885,850 2,023,858 6,712,947 Total revenues $ 11,856 $ 11,043 $ 9,649 $ 7,624 $ 40,172 Property operating expense (3,065 ) (2,306 ) (2,061 ) (2,068 ) (9,500 ) Real estate taxes and insurance (2,266 ) (994 ) (864 ) (631 ) (4,755 ) Total property operating income $ 6,525 $ 7,743 $ 6,724 $ 4,925 25,917 Depreciation and amortization expense (13,928 ) General and administrative (4,112 ) Other expenses (5,635 ) Net income $ 2,242 Capital expenditures (1) $ 3,251 $ 1,478 $ 1,685 $ 520 $ 7,168 Three Months Ended September 30, 2015 Washington, D.C. Maryland Northern Virginia Southern Virginia Consolidated Number of buildings 6 34 49 19 108 Square feet 915,692 1,884,741 3,020,293 2,021,667 7,842,393 Total revenues $ 11,337 $ 10,575 $ 13,715 $ 7,227 $ 42,854 Property operating expense (2,962 ) (2,467 ) (3,347 ) (2,125 ) (10,901 ) Real estate taxes and insurance (2,015 ) (893 ) (1,285 ) (622 ) (4,815 ) Total property operating income $ 6,360 $ 7,215 $ 9,083 $ 4,480 27,138 Depreciation and amortization expense (16,758 ) General and administrative (4,605 ) Other expenses (1,778 ) Net income $ 3,997 Capital expenditures (1) $ 2,440 $ 2,649 $ 11,309 $ 2,019 $ 18,521 Nine Months Ended September 30, 2016 Washington, D.C. Maryland Northern Virginia Southern Virginia Consolidated Total revenues $ 34,725 $ 33,531 $ 30,662 $ 22,443 $ 121,361 Property operating expense (8,596 ) (7,636 ) (7,575 ) (5,773 ) (29,580 ) Real estate taxes and insurance (7,060 ) (2,883 ) (3,104 ) (1,844 ) (14,891 ) Total property operating income $ 19,069 $ 23,012 $ 19,983 $ 14,826 76,890 Depreciation and amortization expense (44,075 ) General and administrative (12,995 ) Impairment of rental property (2,772 ) Other expenses (16,899 ) Net income $ 149 Total assets (2) $ 450,697 $ 336,110 $ 301,706 $ 163,434 $ 1,270,670 Capital expenditures (1) $ 11,449 $ 4,839 $ 29,739 $ 2,254 $ 48,707 Nine Months Ended September 30, 2015 Washington, D.C. Maryland Northern Virginia Southern Virginia Consolidated Total revenues $ 33,522 $ 33,315 $ 41,529 $ 21,375 $ 129,741 Property operating expense (9,088 ) (9,129 ) (10,603 ) (5,856 ) (34,676 ) Real estate taxes and insurance (5,994 ) (2,681 ) (4,178 ) (1,815 ) (14,668 ) Total property operating income $ 18,440 $ 21,505 $ 26,748 $ 13,704 80,397 Depreciation and amortization expense (49,909 ) General and administrative (15,110 ) Other expenses (9,806 ) Loss from discontinued operations (607 ) Net income $ 4,965 Total assets (2)(3) $ 512,245 $ 344,073 $ 452,421 $ 167,882 $ 1,519,609 Capital expenditures (1) $ 9,859 $ 6,965 $ 27,190 $ 5,419 $ 49,846 (1) Capital expenditures for corporate assets not allocated to any of our reportable segments totaled $234 and $104 for the three months ended September 30, 2016 and 2015 , respectively, and $426 and $413 for the nine months ended September 30, 2016 and 2015 , respectively. (2) Total assets include our investment in properties that are owned through joint ventures that are not consolidated within our condensed consolidated financial statements. For more information on our unconsolidated investments, including location within our reportable segments, see note 6 , Investment in Affiliates . Corporate assets not allocated to any of our reportable segments totaled $18,723 and $42,988 at September 30, 2016 and 2015 , respectively. (3) Total assets at September 30, 2015 have been restated to exclude a total of $6.9 million of unamortized deferred financing costs that are now deducted from the respective debt liability in accordance with ASU 2015-03, which we adopted in the first quarter of 2016.

Summary of Significant Accoun22

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2016
Accounting Policies [Abstract]
Principles of Consolidation	) Principles of Consolidation Our unaudited condensed consolidated financial statements include our accounts and the accounts of our Operating Partnership, which we consider to be a variable interest entity (“VIE”), and the subsidiaries in which we or our Operating Partnership has a controlling interest, which includes First Potomac Management, LLC, a wholly-owned subsidiary that manages the majority of our properties. All intercompany balances and transactions have been eliminated in consolidation. We have condensed or omitted certain information and note disclosures normally included in financial statements presented in accordance with U.S. generally accepted accounting principles (“GAAP”) in the accompanying unaudited condensed consolidated financial statements. We believe the disclosures made are adequate to prevent the information presented from being misleading. However, the unaudited condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and notes thereto included in our annual report on Form 10-K for the year ended December 31, 2015 and as updated from time to time in our other filings with the SEC. In our opinion, the accompanying unaudited condensed consolidated financial statements reflect all adjustments, consisting of normal recurring adjustments and accruals necessary to present fairly our financial position as of September 30, 2016 and the results of our operations, our comprehensive income and our cash flows for the three and nine months ended September 30, 2016 and 2015 . Interim results are not necessarily indicative of full-year performance due, in part, to the timing of transactions and the impact of acquisitions and dispositions throughout the year, as well as the seasonality of certain operating expenses such as utilities expense and snow and ice removal costs.
Use of Estimates	Use of Estimates The preparation of unaudited condensed consolidated financial statements in conformity with GAAP requires our management team to make a number of estimates and assumptions relating to the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the unaudited condensed consolidated financial statements and the reported amounts of revenues and expenses during the period. Estimates include the amount of accounts receivable that may be uncollectible, future cash flows, discount and capitalization rate assumptions used to fair value acquired properties and to test impairment of certain long-lived assets and goodwill, derivative valuations, market lease rates, lease-up periods, leasing and tenant improvement costs used to fair value intangible assets acquired and probability weighted cash flow analysis used to fair value contingent liabilities. Actual results could differ from those estimates.
Rental Property	Rental Property Rental property is initially recorded at fair value, when acquired in a business combination, or initial cost when constructed or acquired in an asset purchase. Improvements and replacements are capitalized at cost when they extend the useful life, increase capacity or improve the efficiency of the asset. Repairs and maintenance are charged to expense when incurred. Depreciation and amortization are recorded on a straight-line basis over the estimated useful lives of the assets. The estimated useful lives of our assets, by class, are as follows: Buildings 39 years Building improvements 5 to 20 years Furniture, fixtures and equipment 5 to 15 years Lease related intangible assets The term of the lease Tenant improvements Shorter of the useful life of the asset or the term of the related lease We regularly review market conditions for possible impairment of a property’s carrying value. When circumstances such as adverse market conditions, changes in management’s intended holding period or potential sale to a third party indicate a possible impairment of the carrying value of a property, an impairment analysis is performed. We assess potential impairments based on an estimate of the future undiscounted cash flows (excluding interest charges) expected to result from the property’s use and eventual disposition. This estimate is based on projections of future revenues, expenses, capital improvement costs to maintain the operating capacity, expected holding periods and capitalization rates. These cash flows consider factors such as expected market trends and leasing prospects, as well as the effects of leasing demand, competition and other factors. If impairment exists due to the inability to recover the carrying value of a real estate investment based on forecasted undiscounted cash flows, an impairment loss is recorded to the extent that the carrying value exceeds the estimated fair value of the property. Further, we will record an impairment loss if we expect to dispose of a property in the near term at a price below carrying value. In such an event, we will record an impairment loss based on the difference between a property’s carrying value and its projected sales price less any estimated costs to sell. We will classify a building as held-for-sale in accordance with GAAP in the period in which we have made the decision to dispose of the building, our Board of Trustees or a designated delegate has approved the sale, there is a binding contract pursuant to which the buyer has significant money at risk, or high likelihood a binding agreement to purchase the property will be signed under which the buyer will be required to commit a significant amount of nonrefundable cash, and no significant financing contingencies exist that could cause the transaction not to be completed in a timely manner. We will cease recording depreciation on a building once it has been classified as held-for-sale. We will also determine whether the disposal of a building qualifies as a discontinued operation in accordance with GAAP by assessing whether the disposal of the building, or group of buildings, represents a strategic shift that has, or will have, a major effect on the Company’s operations or financial results. If the building does not qualify as a discontinued operation in accordance with GAAP, we will classify the building’s operating results, together with any impairment charges and any gains or losses on the sale of the building, in continuing operations for all periods presented in our consolidated statements of operations. We will classify the assets and liabilities related to the building as held-for-sale in our consolidated balance sheet for the period the held-for-sale criteria were met. If the building does qualify as a discontinued operation under GAAP, we will classify the building’s operating results, together with any impairment charges and any gains or losses on the sale of the building, in discontinued operations in our consolidated statements of operations for all periods presented and classify the assets and liabilities related to the building as held-for-sale in our consolidated balance sheets for the periods presented. Interest expense is reclassified to discontinued operations only to the extent the disposed or held-for-sale property is secured by specific mortgage debt and the mortgage debt will not be assigned to another property owned by us after the disposition. We recognize the fair value, if sufficient information exists to reasonably estimate the fair value, of any liability for conditional asset retirement obligations when assumed or incurred, which is generally upon acquisition, construction, development or redevelopment and/or through the normal operation of the asset. We capitalize interest costs incurred on qualifying expenditures for real estate assets under development or redevelopment, which include our investments in assets owned through unconsolidated joint ventures that are under development or redevelopment, while being readied for their intended use in accordance with accounting requirements regarding capitalization of interest. We will capitalize interest when qualifying expenditures for the asset have been made, activities necessary to get the asset ready for its intended use are in progress and interest costs are being incurred. Capitalized interest also includes interest associated with expenditures incurred to acquire developable land while development activities are in progress. We also capitalize direct compensation costs of our construction personnel who manage the development and redevelopment projects, but only to the extent the employee’s time can be allocated to a project. Any portion of construction management costs not directly attributable to a specific project are recognized as general and administrative expense in the period incurred. We do not capitalize any other general and administrative costs such as office supplies, office rent expense or an overhead allocation to our development or redevelopment projects. Capitalized compensation costs were immaterial for the three and nine months ended September 30, 2016 and 2015 . Capitalization of interest ends when the asset is substantially complete and ready for its intended use, but no later than one year from completion of major construction activity if the property is not occupied. We place redevelopment and development assets into service at this time and commence depreciation upon the substantial completion of tenant improvements and the recognition of revenue. Capitalized interest is depreciated over the useful life of the underlying assets, commencing when those assets are placed into service.
Notes Receivable	Notes Receivable We provide loans to the owners of real estate properties, which can be collateralized by interest in the real estate property. We record these loans as “Notes receivable” in our consolidated balance sheets. The loans will be recorded net of any discount or issuance costs, which will be amortized over the life of the respective note receivable using the effective interest method. We record interest earned from notes receivable and amortization of any discount costs or issuance costs within “Interest and other income” in our consolidated statements of operations. We will establish a provision for anticipated credit losses associated with our notes receivable when we anticipate that we may be unable to collect any contractually due amounts. This determination is based upon such factors as delinquencies, loss experience, collateral quality and current economic or borrower conditions. Our collectability of our notes receivable may be adversely impacted by the financial stability of the Washington, D.C. region and the ability of the underlying assets to keep current tenants or attract new tenants. Estimated losses are recorded as a charge to earnings to establish an allowance for credit losses that we estimate to be adequate based on these factors. During the second quarter of 2016, we received the full repayment of a mezzanine loan with an outstanding principal balance of $34.0 million . We did not have any notes receivable outstanding at September 30, 2016 . Based on the review of the above criteria, we did not record an allowance for credit losses for our notes receivable during nine months ended September 30, 2015 .
Application of New Accounting Standards	Application of New Accounting Standards In January 2016, we adopted Accounting Standards Update No. 2015-01, Simplifying Income Statement Presentation by Eliminating the Concept of Extraordinary Items (“ASU 2015-01”), which eliminates the concept of extraordinary items from GAAP and the requirement that an entity separately report extraordinary items in the income statement. ASU 2015-01 also requires that entities continue to evaluate whether items are unusual in nature or infrequent in occurrence for presentation and disclosure purposes. The adoption of ASU 2015-01 did not have a material impact on our unaudited condensed consolidated financial statements and related disclosures. In January 2016, we adopted ASU No. 2015-02, Amendments to the Consolidation Analysis (“ASU 2015-02”). This standard amends certain guidance applicable to the consolidation of various legal entities, including variable interest entities (“VIE”). In determining the method of accounting for partially owned joint ventures, we evaluate the characteristics of associated entities and determine whether an entity is a VIE and, if so, determine which party is the primary beneficiary by analyzing whether we have both the power to direct the entity's significant economic activities and the obligation to absorb potentially significant losses or receive potentially significant benefits. Significant judgments and assumptions inherent in this analysis include the nature of the entity's operations, the entity's financing and capital structure, and contractual relationship and terms, including consideration of governance and decision making rights. We consolidate a VIE when we have determined that we are the primary beneficiary. We evaluated the application of ASU 2015-02 and concluded that no change was required to our accounting for any of our interests in less than wholly owned joint ventures. We continued to consolidate our joint venture in Storey Park, which was sold on July 25, 2016, as described in note 12(b), Noncontrolling Interests in a Consolidated Partnership , as it continued to meet the definition and certain criteria as a VIE in which we were considered to be the primary beneficiary. Under ASU 2015-02, our Operating Partnership now meets the definition of a VIE, we are the primary beneficiary, and, accordingly, we continue to consolidate the Operating Partnership. Our sole significant asset is our investment in the Operating Partnership and, consequently, substantially all of our assets and liabilities represent assets and liabilities of the Operating Partnership. All of our debt is an obligation of the Operating Partnership and may only be settled with the assets of the Operating Partnership. In January 2016, we adopted Accounting Standards Update No. 2015-03, Simplifying the Presentation of Debt Issuance Costs (“ASU 2015-03”), which requires debt issuance costs to be presented in the balance sheet as a direct deduction from the carrying value of the debt liability. ASU 2015-03 is applied on a retrospective basis, which resulted in the reclassification of our debt issuance costs from previously presented balances. The guidance did not have a material impact on our unaudited condensed consolidated financial statements and related disclosures. In January 2016, we adopted Accounting Standards Update No. 2015-16, Simplifying the Accounting for Measurement-Period Adjustments (“ASU 2015-16”), which eliminates the requirement for an acquirer to retrospectively adjust the financial statements for measurement-period adjustments that occur in periods after the acquisition of a business combination. The acquirer would instead recognize measurement-period adjustments in the reporting period in which the adjustment is identified. The adoption of ASU 2015-16 did not have a material impact on our unaudited condensed consolidated financial statements and related disclosures. In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update No. 2014-09, Revenue from Contracts with Customers (“ASU 2014-09”), which requires an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers and will replace most existing revenue recognition guidance when it becomes effective. In July 2015, the FASB deferred by one year the mandatory effective date of ASU 2014-09 from January 1, 2017 to January 1, 2018. Early adoption is permitted, but not prior to the original effective date of January 1, 2017. ASU 2014-09 permits the use of either the retrospective or cumulative effect transition method. We have begun to evaluate each of the revenue streams under the new model and the pattern of recognition is not expected to change significantly. We have not yet selected a transition method and are evaluating the impact that ASU 2014-09 will have on our consolidated financial statements and related disclosures. In August 2014, the FASB issued Accounting Standards Update No. 2014-15, Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern (“ASU 2014-15”), which requires an entity to evaluate whether conditions or events, in the aggregate, raise substantial doubt about the entity’s ability to continue as a going concern for one year from the date the financial statements are issued or are available to be issued. The guidance will become effective for annual periods ending after December 15, 2016. The adoption of ASU 2014-15 is not expected to have an impact on our consolidated financial statements and related disclosures. In January 2016, the FASB issued Accounting Standards Update No. 2016-01, Recognition and Measurement of Financial Assets and Financial Liabilities (“ASU 2016-01”), which requires, among other things, entities to use the exit price notion when measuring the fair value of financial instruments for disclosure purposes and eliminates the requirement for public business entities to disclose the method(s) and significant assumptions used to estimate the fair value disclosed for financial instruments measured at amortized cost on the balance sheet. ASU 2016-01 is effective for periods beginning after December 15, 2017; early adoption is not permitted. The guidance is not expected to have a material impact on our consolidated financial statements and related disclosures. In February 2016, the FASB issued Accounting Standards Update No. 2016-02, Leases (“ASU 2016-02”), which requires a lessee to record on the balance sheet a right-of-use asset with a corresponding lease liability created by lease terms of more than 12 months. Additional qualitative and quantitative disclosures will also be required. The guidance will become effective for periods beginning after December 15, 2018 and will be applied using a modified retrospective transition method. We are currently evaluating the impact that ASU 2016-02 will have on our consolidated financial statements and related disclosures. In March 2016, the FASB issued Accounting Standards Update No. 2016-09, Improvements to Employee Share-Based Payment Accounting (“ASU 2016-09”) , which is intended to simplify several aspects of the accounting for employee share-based payment transactions, including income tax consequences, classification of awards as either equity or liabilities and classification on the statement of cash flows. The guidance will become effective for periods beginning after December 15, 2016 and early adoption is permitted. ASU 2016-09 permits the use of the cumulative-effect and prospective methods. We did not elect to early adopt the standard, and the standard is not expected to have a material impact on our consolidated financial statements and related disclosures. In August 2016, the FASB issued Accounting Standards Update No. 2016-15, Classification of Certain Cash Receipts and Cash Payments (“ASU 2016-15”) . The guidance addresses eight classification issues related to the statement of cash flows, including debt prepayment or debt extinguishment costs and distributions received from equity-method investees. The guidance will become effective for periods beginning after December 15, 2017 and early adoption is permitted. ASU 2016-15 requires the use of a retrospective transition method to each period presented. If such retrospective transition is impracticable for certain issues, the adoption of ASU 2016-15 for the applicable issues may be applied prospectively as of the earliest date practicable. While we are currently evaluating the impact of this standard and whether we will elect to early adopt the standard, we do not believe this standard will have a material impact on our consolidated financial statements or related disclosures.
Reclassifications	Reclassifications Certain prior year asset and debt balances have been reclassified to conform to the current year presentation as a result of adopting ASU 2015-03 in January 2016, which requires debt issuance costs to be presented in the balance sheet as a direct deduction from the carrying value of the debt liability and which is applied on a retrospective basis. See note 2(e), Summary of Significant Accounting Policies - Application of New Accounting Standards for more information.

Summary of Significant Accoun23

Summary of Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2016
Accounting Policies [Abstract]
Estimated Useful Life of Assets	Buildings 39 years Building improvements 5 to 20 years Furniture, fixtures and equipment 5 to 15 years Lease related intangible assets The term of the lease Tenant improvements Shorter of the useful life of the asset or the term of the related lease

Earnings Per Common Share (Tabl

Earnings Per Common Share (Tables)	9 Months Ended
	Sep. 30, 2016
Earnings Per Share [Abstract]
Computation of Company's Basic and Diluted Earnings Per Share	The following table sets forth the computation of our basic and diluted earnings per common share (dollars in thousands, except per share amounts): Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Numerator for basic and diluted earnings per common share: Income from continuing operations $ 2,242 $ 3,997 $ 149 $ 5,572 Loss from discontinued operations — — — (607 ) Net income 2,242 3,997 149 4,965 Less: Net (income) loss from continuing operations attributable to noncontrolling interests (107 ) (38 ) 430 163 Less: Net loss from discontinued operations attributable to noncontrolling interests — — — 26 Net income attributable to First Potomac Realty Trust 2,135 3,959 579 5,154 Less: Dividends on preferred shares (11 ) (3,100 ) (3,053 ) (9,300 ) Less: Issuance costs of redeemed preferred shares (1) (517 ) — (5,515 ) — Net income (loss) attributable to common shareholders 1,607 859 (7,989 ) (4,146 ) Less: Allocation to participating securities (53 ) (69 ) (179 ) (211 ) Net income (loss) attributable to common shareholders $ 1,554 $ 790 $ (8,168 ) $ (4,357 ) Denominator for basic and diluted earnings per common share: Weighted average common shares outstanding: Basic 57,597 57,961 57,572 58,155 Diluted 57,825 58,045 57,572 58,155 Basic and diluted earnings per common share: Income (loss) from continuing operations attributable to common shareholders $ 0.03 $ 0.01 $ (0.14 ) $ (0.06 ) Loss from discontinued operations attributable to common shareholders — — — (0.01 ) Net income (loss) attributable to common shareholders $ 0.03 $ 0.01 $ (0.14 ) $ (0.07 ) (1) Represents the original issuance costs associated with the redemption of 0.6 million and 6.4 million 7.750% Series A Cumulative Redeemable Perpetual Preferred Shares during the three and nine months ended September 30, 2016, respectively.
Anti-Dilutive Shares Not Included in Calculation of Diluted Earnings Per Share	In accordance with GAAP regarding earnings per common share, we did not include the following potential weighted average common shares in our calculation of diluted earnings per common share as they are anti-dilutive for the periods presented (amounts in thousands): Three Months Ended Nine Months Ended 2016 2015 2016 2015 Stock option awards 929 987 976 1,037 Non-vested share awards 479 307 533 374 1,408 1,294 1,509 1,411

Rental Property (Tables)

Rental Property (Tables)	9 Months Ended
	Sep. 30, 2016
Real Estate [Abstract]
Summary of Rental Property	Rental property consists of the following (dollars in thousands): September 30, 2016 December 31, 2015 (1) Land and land improvements $ 284,463 $ 280,149 Buildings and improvements 831,076 793,184 Construction in progress 13,982 97,361 Tenant improvements 191,598 168,946 Furniture, fixtures and equipment 398 410 1,321,517 1,340,050 Less: accumulated depreciation (241,547 ) (209,784 ) $ 1,079,970 $ 1,130,266 (1) Excludes rental property totaling $90.6 million at December 31, 2015 related to the NOVA Non-Core Portfolio (as defined in note 7, Dispositions ), which was classified as held-for-sale at December 31, 2015 and was sold on March 25, 2016 .

Investment in Affiliates (Table

Investment in Affiliates (Tables)	9 Months Ended
	Sep. 30, 2016
Equity Method Investments and Joint Ventures [Abstract]
mortgage debt of joint ventures [Table Text Block]	The following table provides a summary of the mortgage debt held by our unconsolidated joint ventures (dollars in thousands): FPO Ownership Effective Interest Rate Maturity Date Principal Balance at September 30, 2016 (1) Principal Balance at December 31, 2015 (1) Rivers Park I and II (2) 25% LIBOR + 1.90% (3) September 2017 $ 28,000 $ 28,000 1750 H Street, NW (4) 50% 3.92% August 2024 32,000 32,000 Prosperity Metro Plaza (5) 51% 3.91% December 2029 50,000 50,000 Weighted Average / Total 3.54% $ 110,000 $ 110,000 (1) Reflects the entire balance of the debt secured by the properties, not our portion of the debt. (2) The loan is repayable in full, without penalty, at any time during the term of the loan. Of the outstanding principal balance, $2.8 million is recourse to us. We believe the fair value of the potential liability to us related to the recourse debt is inconsequential as the likelihood of our need to perform under the debt agreement is remote. (3) At September 30, 2016 , LIBOR was 0.53% . All references to LIBOR in the condensed consolidated financial statements refer to one-month LIBOR. (4) The loan requires interest-only payments with a constant interest rate over the life of the loan. The loan is repayable in full, without penalty, on or after August 1, 2021. (5) The loan requires interest-only payments through December 2024, at which time the loan requires principal and interest payments through its maturity date. The loan is repayable in full without penalty on or after June 1, 2029.
Schedule of Equity Method Investments [Line Items]
Components of Investments in Affiliates	Our investment in affiliates consisted of the following (dollars in thousands): Reporting Segment Ownership Investment at September 30, 2016 Investment at December 31, 2015 Prosperity Metro Plaza Northern Virginia 51% $ 26,180 $ 24,909 1750 H Street, NW Washington, D.C. 50% 14,661 15,168 Aviation Business Park (1) Maryland 50% 5,890 5,899 Rivers Park I and II (1)(2) Maryland 25% 2,378 2,247 $ 49,109 $ 48,223 (1) As of the date of this filing, the applicable joint ventures have engaged sales brokers to market these properties for sale. We anticipate completing the sales in late 2016 or early 2017; however, we can provide no assurances regarding the timing or pricing of such sales, or that such sales will ultimately occur. (2) Rivers Park I and Rivers Park II are owned through two separate joint ventures.
Net Assets of Company's Unconsolidated Joint Ventures	The net assets of our unconsolidated joint ventures consisted of the following (dollars in thousands): September 30, 2016 December 31, 2015 Assets: Rental property, net $ 190,600 $ 193,243 Cash and cash equivalents 7,469 5,992 Other assets 18,914 16,490 Total assets 216,983 215,725 Liabilities: Mortgage loans, net (1)(2) 109,347 109,273 Other liabilities 6,404 7,214 Total liabilities 115,752 116,487 Net assets $ 101,231 $ 99,238 (1) Of the total mortgage debt that encumbers our unconsolidated properties, $2.8 million is recourse to us. We believe the fair value of the potential liability to us under this guaranty is inconsequential as the likelihood of our need to perform under the debt agreement is remote. (2) In the first quarter of 2016, we adopted ASU 2015-03, which requires debt issuance costs to be presented on the balance sheet as a direct deduction from the carrying value of the respective debt liability and which is applied on a retrospective basis. Mortgage loans, net at both September 30, 2016 and December 31, 2015 included $0.7 million of unamortized deferred financing costs.
Results of Operations of Company's Unconsolidated Joint Ventures	The following table summarizes the results of operations of our unconsolidated joint ventures for the periods presented, which, due to our varying ownership interests in the joint ventures and the varying operations of the joint ventures, may not be reflective of the amounts recorded in our consolidated statements of operations (dollars in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Total revenues $ 6,328 $ 5,975 $ 18,857 $ 18,205 Total operating expenses (1,908 ) (1,866 ) (5,888 ) (5,778 ) Net operating income 4,420 4,109 12,969 12,427 Depreciation and amortization (1,996 ) (2,254 ) (5,967 ) (6,790 ) Interest expense, net (1,000 ) (980 ) (2,990 ) (2,928 ) Net income $ 1,424 $ 875 $ 4,012 $ 2,709

Dispositions (Tables)

Dispositions (Tables)	9 Months Ended
	Sep. 30, 2016
Discontinued Operations and Disposal Groups [Abstract]
Discontinued Operations Square Feet Area [Table Text Block]	The following table is a summary of property dispositions whose operating results are included in continuing operations in our consolidated statements of operations for the periods presented (dollars in thousands): Property Reporting Disposition Date Property Type Square Feet Net Sale Proceeds Storey Park (1) Washington, D.C. 7/25/2016 Land — $ 52,659 NOVA Non-Core Portfolio (2) Northern Virginia 3/25/2016 Various 945,745 90,501 Cedar Hill I and III Northern Virginia 12/23/2015 Office 102,632 25,939 Newington Business Park Center Northern Virginia 12/17/2015 Industrial 255,600 31,409 Rumsey Center Maryland 7/28/2015 Business Park 135,015 14,956 (1) This development site could have supported up to 712,000 rentable square feet. (2) Consists of Van Buren Office Park, Herndon Corporate Center, Windsor at Battlefield, Reston Business Campus, Enterprise Center, Gateway Centre Manassas, Linden Business Center and Prosperity Business Center (collectively, the “NOVA Non-Core Portfolio”).
Schedule of Disposal Groups Including Not Discontinued Operations, Income Statement, Balance Sheet and Additional Disclosures [Table Text Block]	The following table summarizes the aggregate results of operations for the disposed or held-for-sale properties that are included in continuing operations for the periods presented (dollars in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Revenues $ — $ 5,118 $ 3,366 $ 16,773 Property operating expenses (60 ) (1,730 ) (1,909 ) (6,282 ) Depreciation and amortization — (1,728 ) (114 ) (5,520 ) Interest expense (44 ) (49 ) (436 ) (461 ) Loss on debt extinguishment — — (48 ) — Impairment of rental property (1) — — (2,772 ) — (Loss) income from operations of disposed property (104 ) 1,611 (1,913 ) 4,510 Gain (loss) on sale of rental property (2) — 3,384 (1,155 ) 3,384 Net (loss) income from continuing operations $ (104 ) $ 4,995 $ (3,068 ) $ 7,894
Summary of Completed Property Dispositions	The following table is a summary of property dispositions whose operating results are reflected as discontinued operations in our consolidated statements of operations for the periods presented (dollars in thousands): Reporting Segment Disposition Date Property Type Square Feet Net Sale Proceeds Richmond Portfolio (1) Southern Virginia 3/19/2015 Business Park 827,900 $ 53,768 (1) Consists of Chesterfield Business Center, Hanover Business Center, Park Central, Virginia Technology Center and a three-acre parcel of undeveloped land (collectively, the “Richmond Portfolio”).
Schedule of Disposal Groups, Including Discontinued Operations, Income Statement, Balance Sheet and Additional Disclosures	The following table summarizes the results of operations of properties included in discontinued operations for the nine months ended September 30, 2015 (dollars in thousands): 2015 Revenues $ 877 Loss from operations, before taxes (1) (975 ) Loss on debt extinguishment (489 ) Gain on sale of rental property 857 (1) For the first quarter of 2015, we accelerated $2.0 million of unamortized straight-line rents, deferred rent abatements and leasing commissions related to the sale of the Richmond Portfolio.

Debt (Tables)

Debt (Tables)	9 Months Ended
	Sep. 30, 2016
Debt Disclosure [Abstract]
Schedule of Borrowings	Our debt consisted of the following (dollars in thousands): September 30, (1) December 31, 2015 (1)(2) Mortgage loans, net, effective interest rates ranging from 4.22% to 6.01%, maturing at various dates through September 2030 (3)(4) $ 309,116 $ 307,769 Unsecured term loan, net, effective interest rates ranging from LIBOR plus 1.45% to LIBOR plus 1.80%, with staggered maturity dates ranging from December 2020 to December 2022 (3) 299,374 299,404 Unsecured revolving credit facility, net, effective interest rate of LIBOR plus 1.50%, maturing December 2019 (3) 130,353 116,865 Total $ 738,843 $ 724,038 (1) In the first quarter of 2016, we adopted ASU 2015-03, which requires debt issuance costs to be presented on the balance sheet as a direct deduction from the carrying value of the respective debt liability and is applied on a retrospective basis. The balances include a total of $6.7 million and $8.0 million of unamortized deferred financing costs at September 30, 2016 and December 31, 2015 , respectively. (2) Excludes $0.2 million of mortgage debt that was classified within “Liabilities held-for-sale” on our consolidated balance sheet at December 31, 2015. See note 7 , Dispositions , for further discussion. (3) At September 30, 2016 , LIBOR was 0.53% . (4) At September 30, 2016, the mortgage loans balance includes two construction loans. At December 31, 2015, the mortgage loans balance includes two construction loans and the Storey Park Land Loan.
Summary of Company's Mortgage Debt	The following table provides a summary of our mortgage debt, which includes two construction loans and a land loan (dollars in thousands): Encumbered Property Contractual Effective Maturity September 30, 2016 December 31, 2015 Storey Park Land Loan (1)(2) LIBOR + 2.50% LIBOR + 2.50% October 2016 $ — $ 22,000 Hillside I and II (3) 5.75% 4.62% December 2016 12,199 12,368 440 First Street, NW Construction Loan (1)(4) LIBOR + 2.50% LIBOR + 2.50% May 2017 32,216 32,216 Redland II and III 4.20% 4.64% November 2017 63,552 64,543 Northern Virginia Construction Loan (1) LIBOR + 1.85% LIBOR + 1.85% September 2019 34,583 9,176 840 First Street, NE 5.72% 6.01% July 2020 35,377 35,888 Battlefield Corporate Center 4.26% 4.40% November 2020 3,397 3,526 1211 Connecticut Avenue, NW 4.22% 4.47% July 2022 28,657 29,110 1401 K Street, NW 4.80% 4.93% June 2023 35,726 36,224 11 Dupont Circle, NW 4.05% 4.22% September 2030 66,780 66,780 Principal balance 4.37% (5) 312,487 311,831 Unamortized fair value adjustments 31 172 Unamortized deferred financing costs (6) (3,402 ) (4,234 ) Total balance, net $ 309,116 $ 307,769 Debt Classified within Liabilities-Held-for-Sale Gateway Centre Manassas Building I (7) 7.35% 5.88% November 2016 — 212 Unamortized fair value adjustments — 1 Total balance, net $ — $ 213 (1) At September 30, 2016 , LIBOR was 0.53% . (2) The Storey Park Land Loan encumbered the Storey Park land and was entered into by our 97% owned consolidated joint venture that owned Storey Park. On July 25, 2016 , our consolidated joint venture sold Storey Park and the Storey Park Land Loan was concurrently repaid with proceeds from the sale. (3) On October 6, 2016 , we prepaid, without penalty, the Hillside I and II loan with a draw on our unsecured revolving credit facility. (4) This construction loan (the “440 First Street, NW Construction Loan”) is collateralized by 440 First Street, NW. In May 2016, we extended the maturity date by one year to May 30, 2017 . We can repay all or a portion of the construction loan, without penalty, at any time during the term of the loan. At September 30, 2016, per the terms of the loan agreement, 50% of the outstanding principal balance and all of the outstanding accrued interest were recourse to us. (5) Represents the weighted average interest rate. (6) In the first quarter of 2016, we adopted ASU 2015-03, which requires debt issuance costs to be presented on the balance sheet as a direct deduction from the carrying value of the respective debt liability and is applied on a retrospective basis. (7) The mortgage loan that encumbered Gateway Centre Manassas, which was included in the NOVA Non-Core Portfolio and sold on March 25, 2016, was classified within “Liabilities held-for-sale” on our December 31, 2015 consolidated balance sheet. In February 2016, we used $0.2 million in available cash to defease the outstanding balance of the mortgage loan.
Unsecured Term Loan	On December 4, 2015, we amended, restated and consolidated our unsecured revolving credit facility and our unsecured term loan. The amendments extended the maturity date of the unsecured term loan’s three $100 million tranches to December 2020, June 2021 and December 2022 from October 2018, October 2019 and October 2020, respectively and the maturity date of the unsecured revolving credit facility to December 2019 from October 2017, with two, six-month extensions at our option. As part of the amendments, we reduced the interest rate spreads on our unsecured term loan and our unsecured revolving credit facility, reduced the capitalization rates used to calculate gross asset value in the financial covenants and amended the covenant package to more closely align with our corporate goals. The table below shows the outstanding balances and the interest rates of the three tranches of the $300.0 million unsecured term loan at September 30, 2016 and December 31, 2015 (dollars in thousands): Maturity Date Interest Rate (1) September 30, 2016 December 31, 2015 Tranche A December 2020 LIBOR + 1.45% $ 100,000 $ 100,000 Tranche B June 2021 LIBOR + 1.45% 100,000 100,000 Tranche C December 2022 LIBOR + 1.80% 100,000 100,000 Total 300,000 300,000 Unamortized deferred financing costs (2) (626 ) (596 ) Total, net $ 299,374 $ 299,404 (1) At September 30, 2016 , LIBOR was 0.53% . The interest rate spread is subject to change based on our maximum total indebtedness ratio. For more information, see note 8 (d), Debt – Financial Covenants .

Derivative Instruments (Tables)

Derivative Instruments (Tables)	9 Months Ended
	Sep. 30, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Summary of Interest Rate Swap Agreements	Our interest rate swap agreements are summarized below (dollars in thousands): Maturity Date Notional Amount Interest Rate Contractual Component Fixed LIBOR Interest Rate July 2017 30,000 LIBOR 2.093 % July 2017 30,000 LIBOR 2.093 % July 2017 25,000 LIBOR 1.129 % July 2017 12,500 LIBOR 1.129 % July 2017 50,000 LIBOR 0.955 % July 2018 12,500 LIBOR 1.383 % July 2018 30,000 LIBOR 1.660 % July 2018 25,000 LIBOR 1.394 % July 2018 25,000 LIBOR 1.135 % Total/Weighted Average $ 240,000 1.442 %

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2016
Fair Value Disclosures [Abstract]
Fair Value of Assets and Liabilities	In accordance with accounting provisions and the fair value hierarchy described above, the following table shows the fair value of our consolidated assets and liabilities that are measured on a non-recurring and recurring basis as of September 30, 2016 and December 31, 2015 (dollars in thousands): Balance at Level 1 Level 2 Level 3 Recurring Measurements: Derivative instrument-swap liabilities $ 2,045 $ — $ 2,045 $ — Balance at Level 1 Level 2 Level 3 Non-recurring Measurements: Impaired real estate assets $ 104,625 $ — $ 90,625 $ 14,000 Recurring Measurements: Derivative instrument-swap liabilities 2,491 — 2,491 —
Fair Value of Debt Instruments	The carrying amount and estimated fair value of our notes receivable and debt instruments are as follows (dollars in thousands): September 30, 2016 December 31, 2015 Carrying (1) Fair Carrying (1) Fair Financial Assets: Notes receivable (2) $ — $ — $ 34,000 $ 34,000 Financial Liabilities: Mortgage debt (3) $ 312,517 $ 324,145 $ 312,216 $ 298,541 Unsecured term loan 300,000 300,000 300,000 300,000 Unsecured revolving credit facility 133,000 133,000 120,000 120,000 Total $ 745,517 $ 757,145 $ 732,216 $ 718,541 (1) In the first quarter of 2016, we adopted ASU 2015-03, which requires debt issuance costs to be presented in the balance sheet as a direct deduction from the carrying value of the respective debt liability and which is applied on a retrospective basis. The debt balances exclude a combined total of $6.7 million and $8.0 million of unamortized deferred financing costs at September 30, 2016 and December 31, 2015, respectively. (2) The note receivable was prepaid on June 2, 2016 . See note 5 , Notes Receivable , for more information regarding the prepayment of the note receivable. (3) Includes $0.2 million of mortgage debt that was classified within “Liabilities held-for-sale” on our consolidated balance sheet at December 31, 2015. See note 7, Dispositions , for additional information.

Equity (Tables)

Equity (Tables)	9 Months Ended
	Sep. 30, 2016
Equity [Abstract]
Company's Allocation between Non-controlling Interests	Our equity and redeemable noncontrolling interests are as follows (dollars in thousands): First Potomac Realty Trust Non-redeemable noncontrolling interests Total Equity Redeemable noncontrolling interests Balance at December 31, 2015 $ 624,528 $ 800 $ 625,328 $ 28,813 Net income (loss) 579 (73 ) 506 (357 ) Changes in ownership, net (155,790 ) — (155,790 ) (1,412 ) Distributions to owners (1) (24,926 ) (727 ) (25,653 ) (909 ) Other comprehensive income, net 432 — 432 20 Balance at September 30, 2016 $ 444,823 $ — $ 444,823 $ 26,155 First Potomac Realty Trust Non-redeemable noncontrolling interests Total Equity Redeemable noncontrolling interests Balance at December 31, 2014 $ 710,007 $ 898 $ 710,905 $ 33,332 Net income (loss) 5,154 (3 ) 5,151 (186 ) Changes in ownership, net 3,289 — 3,289 (1,257 ) Distributions to owners (35,725 ) (96 ) (35,821 ) (1,181 ) Other comprehensive loss, net (1,015 ) — (1,015 ) (45 ) Repurchase of common shares (10,180 ) — (10,180 ) — Balance at September 30, 2015 $ 671,530 $ 799 $ 672,329 $ 30,663
Company's Accumulated Other Comprehensive Loss	A summary of our accumulated other comprehensive loss is as follows (dollars in thousands): 2016 2015 Beginning balance at January 1, $ (2,360 ) $ (3,268 ) Net unrealized gain (loss) on derivative instruments 452 (1,060 ) Net (gain) loss attributable to noncontrolling interests (20 ) 45 Ending balance at September 30, $ (1,928 ) $ (4,283 )

Share-Based Payments (Tables)

Share-Based Payments (Tables)	9 Months Ended
	Sep. 30, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Nonvested Share Activity	A summary of our non-vested common share awards at September 30, 2016 is as follows: Non-vested Common Shares Weighted Average Grant Date Fair Value Non-vested at June 30, 2016 532,069 $ 10.31 Granted 181,357 8.59 Non-vested at September 30, 2016 713,426 $ 9.87

Segment Information (Tables)

Segment Information (Tables)	9 Months Ended
	Sep. 30, 2015
Segment Reporting [Abstract]
Summary of Segment Information	The results of operations of our four reporting segments for the three and nine months ended September 30, 2016 and 2015 are as follows (dollars in thousands): Three Months Ended September 30, 2016 Washington, D.C. Maryland Northern Virginia Southern Virginia Consolidated Number of buildings 6 34 15 19 74 Square feet 917,453 1,885,786 1,885,850 2,023,858 6,712,947 Total revenues $ 11,856 $ 11,043 $ 9,649 $ 7,624 $ 40,172 Property operating expense (3,065 ) (2,306 ) (2,061 ) (2,068 ) (9,500 ) Real estate taxes and insurance (2,266 ) (994 ) (864 ) (631 ) (4,755 ) Total property operating income $ 6,525 $ 7,743 $ 6,724 $ 4,925 25,917 Depreciation and amortization expense (13,928 ) General and administrative (4,112 ) Other expenses (5,635 ) Net income $ 2,242 Capital expenditures (1) $ 3,251 $ 1,478 $ 1,685 $ 520 $ 7,168 Three Months Ended September 30, 2015 Washington, D.C. Maryland Northern Virginia Southern Virginia Consolidated Number of buildings 6 34 49 19 108 Square feet 915,692 1,884,741 3,020,293 2,021,667 7,842,393 Total revenues $ 11,337 $ 10,575 $ 13,715 $ 7,227 $ 42,854 Property operating expense (2,962 ) (2,467 ) (3,347 ) (2,125 ) (10,901 ) Real estate taxes and insurance (2,015 ) (893 ) (1,285 ) (622 ) (4,815 ) Total property operating income $ 6,360 $ 7,215 $ 9,083 $ 4,480 27,138 Depreciation and amortization expense (16,758 ) General and administrative (4,605 ) Other expenses (1,778 ) Net income $ 3,997 Capital expenditures (1) $ 2,440 $ 2,649 $ 11,309 $ 2,019 $ 18,521 Nine Months Ended September 30, 2016 Washington, D.C. Maryland Northern Virginia Southern Virginia Consolidated Total revenues $ 34,725 $ 33,531 $ 30,662 $ 22,443 $ 121,361 Property operating expense (8,596 ) (7,636 ) (7,575 ) (5,773 ) (29,580 ) Real estate taxes and insurance (7,060 ) (2,883 ) (3,104 ) (1,844 ) (14,891 ) Total property operating income $ 19,069 $ 23,012 $ 19,983 $ 14,826 76,890 Depreciation and amortization expense (44,075 ) General and administrative (12,995 ) Impairment of rental property (2,772 ) Other expenses (16,899 ) Net income $ 149 Total assets (2) $ 450,697 $ 336,110 $ 301,706 $ 163,434 $ 1,270,670 Capital expenditures (1) $ 11,449 $ 4,839 $ 29,739 $ 2,254 $ 48,707 Nine Months Ended September 30, 2015 Washington, D.C. Maryland Northern Virginia Southern Virginia Consolidated Total revenues $ 33,522 $ 33,315 $ 41,529 $ 21,375 $ 129,741 Property operating expense (9,088 ) (9,129 ) (10,603 ) (5,856 ) (34,676 ) Real estate taxes and insurance (5,994 ) (2,681 ) (4,178 ) (1,815 ) (14,668 ) Total property operating income $ 18,440 $ 21,505 $ 26,748 $ 13,704 80,397 Depreciation and amortization expense (49,909 ) General and administrative (15,110 ) Other expenses (9,806 ) Loss from discontinued operations (607 ) Net income $ 4,965 Total assets (2)(3) $ 512,245 $ 344,073 $ 452,421 $ 167,882 $ 1,519,609 Capital expenditures (1) $ 9,859 $ 6,965 $ 27,190 $ 5,419 $ 49,846 (1) Capital expenditures for corporate assets not allocated to any of our reportable segments totaled $234 and $104 for the three months ended September 30, 2016 and 2015 , respectively, and $426 and $413 for the nine months ended September 30, 2016 and 2015 , respectively. (2) Total assets include our investment in properties that are owned through joint ventures that are not consolidated within our condensed consolidated financial statements. For more information on our unconsolidated investments, including location within our reportable segments, see note 6 , Investment in Affiliates . Corporate assets not allocated to any of our reportable segments totaled $18,723 and $42,988 at September 30, 2016 and 2015 , respectively. (3) Total assets at September 30, 2015 have been restated to exclude a total of $6.9 million of unamortized deferred financing costs that are now deducted from the respective debt liability in accordance with ASU 2015-03, which we adopted in the first quarter of 2016.

Description of Business - Addit

Description of Business - Additional Information (Detail)	3 Months Ended
	Sep. 30, 2016ft²joint_venturepersonIntegersegment	Sep. 30, 2015ft²	[1]
Real Estate Properties [Line Items]
Number of Reportable Segments | segment	4
Interest in Operating Partnership	95.80%
Area of real estate property	6,712,947	7,842,393
Unconsolidated joint ventures | joint_venture	5
Square Footage Of Land For Additional Development	600,000
Occupancy rate in the Company's consolidated properties	92.80%
Number of tenants representing current occupancy rate | person	382
Percent of Annualized Cash Rent	26.90%
Wholly-owned Properties [Member]
Real Estate Properties [Line Items]
Number of Reportable Segments | Integer	4
Area of real estate property	6,700,000
Unconsolidated Properties [Member]
Real Estate Properties [Line Items]
Area of real estate property	900,000
US Government [Member]
Real Estate Properties [Line Items]
Percent of Annualized Cash Rent	15.70%
Washington D C Reporting Segment [Member]
Real Estate Properties [Line Items]
Area Of Land Available For Development In Additional Building Space	0
[1]	Total assets include our investment in properties that are owned through joint ventures that are not consolidated within our condensed consolidated financial statements. For more information on our unconsolidated investments, including location within our reportable segments, see note 6, Investment in Affiliates. Corporate assets not allocated to any of our reportable segments totaled $18,723 and $42,988 at September 30, 2016 and 2015, respectively.

Summary of Significant Accoun35

Summary of Significant Accounting Policies - Estimated Useful Lives of Company's Assets, by Class (Detail)	3 Months Ended
	Sep. 30, 2016
Property, Plant and Equipment [Line Items]
Useful life	39 years
Lease related intangible assets	the term of the lease
Tenant improvements	Shorter of the useful life of the asset or the term of the related lease
Minimum [Member] | Building improvements
Property, Plant and Equipment [Line Items]
Useful life	5 years
Minimum [Member] | Furniture, fixtures and equipment
Property, Plant and Equipment [Line Items]
Useful life	5 years
Maximum [Member] | Building improvements
Property, Plant and Equipment [Line Items]
Useful life	20 years
Maximum [Member] | Furniture, fixtures and equipment
Property, Plant and Equipment [Line Items]
Useful life	15 years

Summary of Significant Accoun36

Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)	3 Months Ended		6 Months Ended	9 Months Ended
	Sep. 30, 2016	Jun. 30, 2016	Jun. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Loans and Leases Receivable Disclosure [Line Items]
Principal payments from note receivable				$ 34,000,000	$ 29,720,000
Notes receivable	$ 0			0		$ 34,000,000
Allowance for credit losses for its notes receivable			$ 0	$ 0
Nine Hundered And Fifty Street Nw [Member]
Loans and Leases Receivable Disclosure [Line Items]
Principal payments from note receivable	$ 34,000,000	$ 34,000,000

Earnings Per Common Share - Com

Earnings Per Common Share - Computation of Company's Basic and Diluted Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended				9 Months Ended
	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Numerator for basic and diluted earnings per common share:
Income from continuing operations	$ 2,242			$ 3,997	$ 149	$ 5,572
Loss from discontinued operations	0			0	0	(607)
Net income	2,242			3,997	149	4,965
Less: Net (income) loss from continuing operations attributable to noncontrolling interests	(107)			(38)	430	163
Less: Net loss from discontinued operations attributable to noncontrolling interests	0			0	0	26
Net income attributable to First Potomac Realty Trust	2,135			3,959	579	5,154
Less: Dividends on preferred shares	(11)			(3,100)	(3,053)	(9,300)
Less: Issuance costs of redeemed preferred shares	517			0	5,515	0
Net income (loss) attributable to common shareholders	1,607			859	(7,989)	(4,146)
Less: Allocation to participating securities	(53)			(69)	(179)	(211)
Net income (loss) attributable to common shareholders	$ 1,554			$ 790	$ (8,168)	$ (4,357)
Denominator for basic and diluted earnings per common share:
Basic	57,597			57,961	57,572	58,155
Weighted Average Number of Shares Outstanding, Diluted	57,825			58,045	57,572	58,155
Basic and diluted earnings per common share:
Loss from continuing operations	$ 0.03			$ 0.01	$ (0.14)	$ (0.06)
Loss from discontinued operations attributable to common shareholders	0			0	0	(0.01)
Net income (loss) attributable to common shareholders	$ 0.03			$ 0.01	$ (0.14)	$ (0.07)
Series A Preferred Stock [Member]
Class of Stock [Line Items]
Stock Redeemed or Called During Period, Shares	600	3,600	2,200		6,400

Earnings Per Common Share - Ant

Earnings Per Common Share - Anti-Dilutive Shares Not Included in Calculation of Diluted Earnings Per Share (Detail) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of earnings per share, Amount	1,408	1,294	1,509	1,411
Stock option awards
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of earnings per share, Amount	929	987	976	1,037
Non-vested share awards
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of earnings per share, Amount	479	307	533	374

Rental Property - Summary of Re

Rental Property - Summary of Rental Property (Detail) - USD ($) $ in Thousands		3 Months Ended	9 Months Ended
		Sep. 30, 2016	Sep. 30, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Real Estate Investment Property, Net		$ 1,079,970	$ 1,079,970	$ 1,130,266
Rental property, net		1,079,970	1,079,970	1,130,266
Rental Property [Member]
Property, Plant and Equipment [Line Items]
Land and land improvements		284,463	284,463	280,149
Buildings and improvements		831,076	831,076	793,184
Construction in process		13,982	13,982	97,361
Tenant Improvements		191,598	191,598	168,946
Furniture, fixtures and equipment		398	398	410
Rental property, gross		1,321,517	1,321,517	1,340,050
Less: accumulated depreciation		$ (241,547)	$ (241,547)	(209,784)
NOVA Non-Core Portfolio [Member] | Rental Property [Member]
Property, Plant and Equipment [Line Items]
Disposition Date Of Property		Mar. 25, 2016
NOVA Non-Core Portfolio [Member]
Property, Plant and Equipment [Line Items]
Buildings and improvements				88,000
Tenant Improvements				14,400
Disposition Date Of Property	[1]		Mar. 25, 2016
NOVA Non-Core Portfolio [Member] | Disposal Group, Held-for-sale, Not Discontinued Operations [Member]
Property, Plant and Equipment [Line Items]
Rental property, net				$ 90,600
[1]	Consists of Van Buren Office Park, Herndon Corporate Center, Windsor at Battlefield, Reston Business Campus, Enterprise Center, Gateway Centre Manassas, Linden Business Center and Prosperity Business Center (collectively, the “NOVA Non-Core Portfolio”).

Rental Property - Additional In

Rental Property - Additional Information (Detail) $ in Thousands	Jul. 25, 2016USD ($)	Aug. 31, 2013aft²	Sep. 30, 2016USD ($)ft²	Sep. 30, 2016USD ($)ft²		Sep. 30, 2015USD ($)	Aug. 04, 2011
Segment Reporting Information [Line Items]
Square Footage Of Land For Additional Development			600,000	600,000
Impairment of rental property | $				$ 2,772		$ 0
Ownership Interest							97.00%
Placed in-service redevelopment efforts			0
Storey Park [Member]
Segment Reporting Information [Line Items]
Business Combination, Consideration Transferred | $	$ 54,500
Proceeds from sale of properties | $			$ 52,700	$ 52,659	[1]
Impairment of rental property | $			$ 2,800
Disposition Date Of Property	Jul. 25, 2016			Jul. 25, 2016	[1]
Ownership Interest			97.00%	97.00%
Washington D C Reporting Segment [Member]
Segment Reporting Information [Line Items]
Area Of Land Available For Development In Additional Building Space			0
Lease expiration date		Aug. 31, 2013
Development of area for operations by joint venture | a		1.6
Washington D C Reporting Segment [Member] | Maximum [Member] | Greyhound Property [Member]
Segment Reporting Information [Line Items]
Area Of Land Available For Development In Additional Building Space		712,000
Maryland Reporting Segment [Member]
Segment Reporting Information [Line Items]
Area Of Land Available For Development In Additional Building Space			100,000
Northern Virginia
Segment Reporting Information [Line Items]
Area Of Land Available For Development In Additional Building Space			400,000
Area of land placed under development				167,000
Projected incremental investment in development project | $			$ 34,600	$ 34,600
Original cost basis of the property | $			$ 5,200	$ 5,200
Southern Virginia [Member]
Segment Reporting Information [Line Items]
Area Of Land Available For Development In Additional Building Space			100,000
[1]	1) This development site could have supported up to 712,000 rentable square feet.

Notes Receivable - Additional I

Notes Receivable - Additional Information (Detail) $ in Thousands

Apr. 01, 2011

Sep. 30, 2016USD ($)ft²shares

Jun. 30, 2016USD ($)

Sep. 30, 2015USD ($)ft²

Jun. 30, 2015

Sep. 30, 2016USD ($)ft²shares

Sep. 30, 2015USD ($)ft²

Jul. 06, 2016shares

Dec. 31, 2015USD ($)shares

Feb. 24, 2015USD ($)

Apr. 30, 2011ft²

Receivables with Imputed Interest [Line Items]

Area of real estate property | ft²

6,712,947

7,842,393

[1]

6,712,947

7,842,393

[1]

Unsecured revolving credit facility, net

$ 130,353

$ 130,353

$ 116,865

Series A Preferred Shares, shares outstanding | shares

600,000

600,000

6,400,000

Interest income

$ 800

$ 1,600

$ 2,900

America Square [Member]

Receivables with Imputed Interest [Line Items]

Area of real estate property | ft²

461,000

Loans Receivable, Gross, Commercial, Real Estate

$ 29,700

Maturity date of loan

May 1, 2016

Apr. 1, 2017

Prepayment Fee Income

$ 2,400

America Square [Member] | Maximum [Member]

Receivables with Imputed Interest [Line Items]

Fixed interest rate on loan

9.00%

Nine Hundered And Fifty Street Nw [Member]

Receivables with Imputed Interest [Line Items]

Area of real estate property | ft²

287,000

287,000

Recognition of Deferred Revenue

$ 200

Nine Hundered And Fifty Street Nw [Member] | Minimum [Member]

Receivables with Imputed Interest [Line Items]

Fixed interest rate on loan

9.75%

Series A Preferred Stock [Member]

Receivables with Imputed Interest [Line Items]

Series A Preferred Shares, shares outstanding | shares

600,000

6,400,000

[1]

Total assets include our investment in properties that are owned through joint ventures that are not consolidated within our condensed consolidated financial statements. For more information on our unconsolidated investments, including location within our reportable segments, see note 6, Investment in Affiliates. Corporate assets not allocated to any of our reportable segments totaled $18,723 and $42,988 at September 30, 2016 and 2015, respectively.

Investment in Affiliates - Comp

Investment in Affiliates - Components of Investments in Affiliates (Detail) - USD ($) $ in Thousands		3 Months Ended
		Sep. 30, 2016	Dec. 31, 2015	Aug. 04, 2011
Schedule of Equity Method Investments [Line Items]
Ownership Interest				97.00%
Company Investment		$ 49,109	$ 48,223
Prosperity Metro Plaza [Member]
Schedule of Equity Method Investments [Line Items]
Reporting Segment		Northern Virginia
Ownership Interest	[1]	51.00%
Company Investment		$ 26,180	24,909
One Thousand Seven Hundred Fifty H Street Nw [Member]
Schedule of Equity Method Investments [Line Items]
Reporting Segment		Washington, D.C.
Ownership Interest	[2]	50.00%
Company Investment		$ 14,661	15,168
Aviation Business Park
Schedule of Equity Method Investments [Line Items]
Reporting Segment		Maryland
Ownership Interest		50.00%
Company Investment		$ 5,890	5,899
Rivers Park One And Two [Member]
Schedule of Equity Method Investments [Line Items]
Reporting Segment		Maryland
Ownership Interest	[3]	25.00%
Company Investment		$ 2,378	$ 2,247
Mortgages [Member] | Rivers Park One And Two [Member]
Schedule of Equity Method Investments [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted		$ 2,800
[1]	The loan requires interest-only payments through December 2024, at which time the loan requires principal and interest payments through its maturity date. The loan is repayable in full without penalty on or after June 1, 2029.
[2]	The loan requires interest-only payments with a constant interest rate over the life of the loan. The loan is repayable in full, without penalty, on or after August 1, 2021.
[3]	The loan is repayable in full, without penalty, at any time during the term of the loan. Of the outstanding principal balance, $2.8 million is recourse to us. We believe the fair value of the potential liability to us related to the recourse debt is inconsequential as the likelihood of our need to perform under the debt agreement is remote.

Investment in Affiliates - Net

Investment in Affiliates - Net Assets of Company's Unconsolidated Joint Ventures (Detail) - USD ($) $ in Thousands		Sep. 30, 2016		Dec. 31, 2015	Sep. 30, 2015		Dec. 31, 2014
Assets:
Rental property, net		$ 1,079,970		$ 1,130,266
Cash and cash equivalents		14,767		13,527	$ 12,875		$ 13,323
Total assets		1,270,670	[1]	1,442,406	1,519,609	[1],[2]
Liabilities:
Total liabilities		799,692		788,265
Recourse mortgage debt		738,843		724,038
Debt Issuance Costs, Line of Credit Arrangements, Net		2,600			$ 6,900
Unconsolidated Joint Ventures [Member]
Assets:
Rental property, net		190,600		193,243
Cash and cash equivalents		7,469		5,992
Other assets		18,914		16,490
Total assets		216,983		215,725
Liabilities:
Mortgage loans	[3]	109,347		109,273
Other liabilities		6,404		7,214
Total liabilities		115,752		116,487
Net assets		101,231		99,238
Debt Issuance Costs, Line of Credit Arrangements, Net				$ 700
Unconsolidated Entities
Liabilities:
Recourse mortgage debt		$ 2,800
[1]	Total assets include our investment in properties that are owned through joint ventures that are not consolidated within our condensed consolidated financial statements. For more information on our unconsolidated investments, including location within our reportable segments, see note 6, Investment in Affiliates. Corporate assets not allocated to any of our reportable segments totaled $18,723 and $42,988 at September 30, 2016 and 2015, respectively.
[2]	Total assets at September 30, 2015 have been restated to exclude a total of $6.9 million of unamortized deferred financing costs that are now deducted from the respective debt liability in accordance with ASU 2015-03, which we adopted in the first quarter of 2016.
[3]	Of the total mortgage debt that encumbers our unconsolidated properties, $2.8 million is recourse to us. We believe the fair value of the potential liability to us under this guaranty is inconsequential as the likelihood of our need to perform under the debt agreement is remote.

Investment in Affiliates - Addi

Investment in Affiliates - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Equity Method Investments and Joint Ventures [Abstract]
Fees from joint ventures	$ 0	$ 0.2	$ 0.4	$ 0.5

Investment in Affiliates - Resu

Investment in Affiliates - Results of Operations of Company's Unconsolidated Joint Ventures (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Schedule of Equity Method Investments [Line Items]
Total revenues	$ 40,172	$ 42,854	$ 121,361	$ 129,741
Total operating expenses	(32,295)	(37,079)	(104,313)	(114,363)
Operating income	7,877	5,775	17,048	15,378
Depreciation and amortization	(13,928)	(16,758)	(44,075)	(49,909)
Interest expense, net	(5,635)	(1,778)	(16,899)	(9,806)
Net income	664	432	1,883	1,235
Unconsolidated Joint Ventures [Member]
Schedule of Equity Method Investments [Line Items]
Total revenues	6,328	5,975	18,857	18,205
Total operating expenses	(1,908)	(1,866)	(5,888)	(5,778)
Operating income	4,420	4,109	12,969	12,427
Depreciation and amortization	(1,996)	(2,254)	(5,967)	(6,790)
Interest expense, net	(1,000)	(980)	(2,990)	(2,928)
Net income	$ 1,424	$ 875	$ 4,012	$ 2,709

Investment in Affiliates Invest

Investment in Affiliates Investment in Affiliates - Mortgage Debt Held by Unconsolidated Joint Ventures (Details) (Details) - USD ($) $ in Thousands		9 Months Ended
		Sep. 30, 2016	Dec. 31, 2015	Sep. 30, 2015	Aug. 04, 2011
Schedule of Equity Method Investments [Line Items]
Debt Issuance Costs, Line of Credit Arrangements, Net		$ 2,600		$ 6,900
Total long term debt		$ 738,843	$ 724,038
Ownership Interest					97.00%
Unconsolidated Joint Ventures [Member]
Schedule of Equity Method Investments [Line Items]
Debt Issuance Costs, Line of Credit Arrangements, Net			700
Rivers Park One And Two [Member]
Schedule of Equity Method Investments [Line Items]
Ownership Interest	[1]	25.00%
One Thousand Seven Hundred Fifty H Street Nw [Member]
Schedule of Equity Method Investments [Line Items]
Ownership Interest	[2]	50.00%
Prosperity Metro Plaza [Member]
Schedule of Equity Method Investments [Line Items]
Ownership Interest	[3]	51.00%
Mortgages [Member]
Schedule of Equity Method Investments [Line Items]
Total long term debt	[4]	$ 110,000	110,000
Effective Interest Rate		3.54%
Mortgages [Member] | Rivers Park One And Two [Member]
Schedule of Equity Method Investments [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted		$ 2,800
Mortgage and Other Indebtedness	[1],[4]	28,000	28,000
Mortgages [Member] | One Thousand Seven Hundred Fifty H Street Nw [Member]
Schedule of Equity Method Investments [Line Items]
Mortgage and Other Indebtedness	[2],[4]	$ 32,000	32,000
Effective Interest Rate	[2]	3.92%
Mortgages [Member] | Prosperity Metro Plaza [Member]
Schedule of Equity Method Investments [Line Items]
Mortgage and Other Indebtedness	[3],[4]	$ 50,000	$ 50,000
Effective Interest Rate	[3]	3.91%
London Interbank Offered Rate (LIBOR) [Member]
Schedule of Equity Method Investments [Line Items]
Effective Interest Rate		0.53%
London Interbank Offered Rate (LIBOR) [Member] | Mortgages [Member] | Rivers Park One And Two [Member]
Schedule of Equity Method Investments [Line Items]
Interest Rate	[5]	LIBOR
Derivative, Basis Spread on Variable Rate		1.90%
[1]	The loan is repayable in full, without penalty, at any time during the term of the loan. Of the outstanding principal balance, $2.8 million is recourse to us. We believe the fair value of the potential liability to us related to the recourse debt is inconsequential as the likelihood of our need to perform under the debt agreement is remote.
[2]	The loan requires interest-only payments with a constant interest rate over the life of the loan. The loan is repayable in full, without penalty, on or after August 1, 2021.
[3]	The loan requires interest-only payments through December 2024, at which time the loan requires principal and interest payments through its maturity date. The loan is repayable in full without penalty on or after June 1, 2029.
[4]	Reflects the entire balance of the debt secured by the properties, not our portion of the debt.
[5]	At September 30, 2016, LIBOR was 0.53%. All references to LIBOR in the condensed consolidated financial statements refer to one-month LIBOR.

Dispositions - Additional Infor

Dispositions - Additional Information (Detail) - USD ($) $ in Thousands

Jul. 25, 2016

Sep. 30, 2016

Mar. 31, 2016

Sep. 30, 2015

Mar. 31, 2015

Sep. 30, 2016

Sep. 30, 2015

Dec. 31, 2015

SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]

(Gain) loss on sale of rental property

$ 0

$ (1,200)

$ 3,384

$ (1,155)

$ 3,384

Assets

1,270,670

[1]

$ 1,519,609

[1],[2]

$ 1,270,670

[1]

$ 1,519,609

[1],[2]

$ 1,442,406

NOVA Non-Core Portfolio [Member]

SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]

Disposition Date Of Property

[3]

Mar. 25, 2016

Proceeds from sale of properties

[3]

$ 90,501

Land and Land Improvements

25,200

Buildings and improvements

88,000

Tenant Improvements

14,400

Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment

$ 37,000

Storey Park [Member]

SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]

Disposition Date Of Property

Jul. 25, 2016

Jul. 25, 2016

[4]

Proceeds from sale of properties

52,700

$ 52,659

[4]

Mortgage loans, net, effective interest rates ranging from 4.22% to 6.01%, maturing at various dates through September 2030(3)(4)

$ 22,000

$ 22,000

Noncontrolling Interest, Description

0.03

Richmond [Member]

SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]

Disposition Date Of Property

[5]

Mar. 19, 2015

Proceeds from sale of properties

[5]

$ 53,768

[1]

Total assets include our investment in properties that are owned through joint ventures that are not consolidated within our condensed consolidated financial statements. For more information on our unconsolidated investments, including location within our reportable segments, see note 6, Investment in Affiliates. Corporate assets not allocated to any of our reportable segments totaled $18,723 and $42,988 at September 30, 2016 and 2015, respectively.

[2]

Total assets at September 30, 2015 have been restated to exclude a total of $6.9 million of unamortized deferred financing costs that are now deducted from the respective debt liability in accordance with ASU 2015-03, which we adopted in the first quarter of 2016.

[3]

Consists of Van Buren Office Park, Herndon Corporate Center, Windsor at Battlefield, Reston Business Campus, Enterprise Center, Gateway Centre Manassas, Linden Business Center and Prosperity Business Center (collectively, the “NOVA Non-Core Portfolio”).

[4]

1) This development site could have supported up to 712,000 rentable square feet.

[5]

Consists of Chesterfield Business Center, Hanover Business Center, Park Central, Virginia Technology Center and a three-acre parcel of undeveloped land (collectively, the “Richmond Portfolio”).

Dispositions Dispositions - Dis

Dispositions Dispositions - Disposed or Held-for-Sale Properties within Continuing Operations (Details) $ in Thousands

Jul. 25, 2016

Sep. 30, 2016USD ($)ft²

Mar. 31, 2016USD ($)

Sep. 30, 2015USD ($)ft²

Jun. 30, 2015USD ($)

Sep. 30, 2016USD ($)ft²

Sep. 30, 2015USD ($)ft²

Jun. 30, 2016ft²

Dec. 31, 2015USD ($)ft²

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Square feet | ft²

6,712,947

7,842,393

[1]

6,712,947

7,842,393

[1]

Gain (Loss) on Extinguishment of Debt

$ 0

$ 0

$ (48)

$ 0

Impairment of rental property

0

0

2,772

0

(Gain) loss on sale of rental property

$ 0

$ (1,200)

$ 3,384

$ (1,155)

$ 3,384

Storey Park [Member]

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Reporting Segment

[2]

Washington, D.C.

Disposition Date Of Property

Jul. 25, 2016

Jul. 25, 2016

[2]

Property Type

[2]

Land

Square feet | ft²

0

0

712,000

[2]

Proceeds from sale of properties

$ 52,700

$ 52,659

[2]

Rumsey Center [Domain]

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Reporting Segment

Maryland

Disposition Date Of Property

Jul. 28, 2015

Property Type

Business Park

Square feet | ft²

135,015

135,015

Proceeds from sale of properties

$ 14,956

Newington Business Park Center [Member]

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Reporting Segment

Northern Virginia

Disposition Date Of Property

Dec. 17, 2015

Property Type

Industrial

Square feet | ft²

255,600

Proceeds from sale of properties

$ 31,409

NOVA Non-Core Portfolio [Member]

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Reporting Segment

[3]

Northern Virginia

Disposition Date Of Property

[3]

Mar. 25, 2016

Property Type

[3]

Various

Square feet | ft²

[3]

945,745

Proceeds from sale of properties

[3]

$ 90,501

Land and Land Improvements

$ 25,200

Tenant Improvements

14,400

Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment

$ 37,000

Cedar Hill I and III [Member]

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Reporting Segment

Northern Virginia

Disposition Date Of Property

Dec. 23, 2015

Property Type

Office

Square feet | ft²

102,632

Proceeds from sale of properties

$ 25,939

Disposed or held-for-sale properties in continuing operations | Continuing Operations

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Revenues

0

$ 5,118

$ 16,773

3,366

Property operating expenses

(60)

(1,730)

(6,282)

(1,909)

Depreciation and amortization

0

(1,728)

(5,520)

(114)

Interest Expense

(44)

(49)

(461)

(436)

Gain (Loss) on Extinguishment of Debt

0

0

0

(48)

Impairment of rental property

[4]

0

0

0

2,772

Operating Income (Loss) from Continuing Operations Attributable to Parent

(104)

1,611

4,510

(1,913)

(Gain) loss on sale of rental property

0

3,384

3,384

(1,155)

[5]

Net (loss) income from continuing operations

$ (104)

$ 4,995

$ 7,894

(3,068)

Disposed or held-for-sale properties in continuing operations | Rumsey Center [Domain] | Continuing Operations

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Impairment of rental property

[4]

3,400

Disposed or held-for-sale properties in continuing operations | NOVA Non-Core Portfolio [Member] | Continuing Operations

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Impairment of rental property

[4]

$ 1,200

Storey Park [Member]

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Disposition Date Of Property

Jul. 25, 2016

[1]

Total assets include our investment in properties that are owned through joint ventures that are not consolidated within our condensed consolidated financial statements. For more information on our unconsolidated investments, including location within our reportable segments, see note 6, Investment in Affiliates. Corporate assets not allocated to any of our reportable segments totaled $18,723 and $42,988 at September 30, 2016 and 2015, respectively.

[2]

1) This development site could have supported up to 712,000 rentable square feet.

[3]

Consists of Van Buren Office Park, Herndon Corporate Center, Windsor at Battlefield, Reston Business Campus, Enterprise Center, Gateway Centre Manassas, Linden Business Center and Prosperity Business Center (collectively, the “NOVA Non-Core Portfolio”).

[4]

During the second quarter of 2016, we recorded an impairment charge related to Storey Park based on the anticipated sales price less estimated selling costs. The property was sold on July 25, 2016.

[5]

During the first quarter of 2016, we recorded a $1.2 million loss on the sale of the NOVA Non-Core Portfolio, and in the third quarter of 2015, we recorded a $3.4 million gain on the sale of Rumsey Center.

Dispositions - Summary of Compl

Dispositions - Summary of Completed Property Dispositions (Detail) $ in Thousands		3 Months Ended
		Mar. 31, 2015USD ($)ft²	Sep. 30, 2016ft²	Sep. 30, 2015ft²	[1]
Schedule Of Discontinued Operations [Line Items]
Square feet			6,712,947	7,842,393
Richmond [Member]
Schedule Of Discontinued Operations [Line Items]
Reporting Segment	[2]	Southern Virginia
Disposition Date Of Property	[2]	Mar. 19, 2015
Property Type	[2]	Business Park
Square feet	[2]	827,900
Proceeds from sale of properties | $	[2]	$ 53,768
[1]	Total assets include our investment in properties that are owned through joint ventures that are not consolidated within our condensed consolidated financial statements. For more information on our unconsolidated investments, including location within our reportable segments, see note 6, Investment in Affiliates. Corporate assets not allocated to any of our reportable segments totaled $18,723 and $42,988 at September 30, 2016 and 2015, respectively.
[2]	Consists of Chesterfield Business Center, Hanover Business Center, Park Central, Virginia Technology Center and a three-acre parcel of undeveloped land (collectively, the “Richmond Portfolio”).

Dispositions - Net (Loss) Incom

Dispositions - Net (Loss) Income from Discontinued Operations (Detail) - USD ($) $ in Thousands		3 Months Ended			6 Months Ended	9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Mar. 31, 2015	Jun. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loss on debt extinguishment		$ 0	$ 0			$ 0	$ (489)
Richmond [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Accelerated Amount Of Straight Line Rent				$ 2,000
Discontinued Operations [Member] | All properties classified within discontinued operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenues					$ 877
Loss from operations, before taxes	[1]				(975)
Loss on debt extinguishment					(489)
Gain on sale of rental property					$ 857
[1]	(1) For the first quarter of 2015, we accelerated $2.0 million of unamortized straight-line rents, deferred rent abatements and leasing commissions related to the sale of the Richmond Portfolio.

Debt - Schedule of Borrowings (

Debt - Schedule of Borrowings (Detail) - USD ($) $ in Thousands		3 Months Ended	9 Months Ended
		Sep. 30, 2016	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Debt Instrument [Line Items]
Repayments of debt			$ 210,964	$ 226,155
Debt Issuance Costs, Net		$ 6,700	6,700		$ 8,000
Mortgage loans, net		309,116	309,116		307,769
Unsecured Debt		299,374	299,374		299,404
Unsecured revolving credit facility, net		130,353	130,353		116,865
Total long term debt		738,843	$ 738,843		724,038
Mortgage Loan [Member]
Debt Instrument [Line Items]
Debt instrument maturity date			June 2,030
Unsecured Term Loan, Effective Interest Rates Ranging from LIBOR Plus 1.45% to LIBOR Plus 1.90%, with Staggered Maturity Dates ranging from October 2018 to October 2020
Debt Instrument [Line Items]
Unsecured Debt		299,374	$ 299,374		299,404
Debt instrument maturity date			December 2020 to December 2022
Debt Instrument Basis Spread On Variable Rate Minimum			1.30%
Debt Instrument Basis Spread On Variable Rate Maximum			1.60%
Unsecured revolving credit facility
Debt Instrument [Line Items]
Repayments of debt		37,000
Unsecured revolving credit facility, net, effective interest rate of LIBOR plus 1.50%, maturing December 2019(3)		$ 133,000	$ 133,000
Effective interest rate on the notes		1.35%	1.35%
Debt instrument maturity date			December 2,019
Storey Park [Member]
Debt Instrument [Line Items]
Repayments of debt		$ 27,000
Unsecured Debt [Member]
Debt Instrument [Line Items]
Repayments of debt		$ 10,000
Minimum [Member] | Mortgage Loan [Member]
Debt Instrument [Line Items]
Effective interest rate on the notes		4.22%	4.22%
Maximum [Member] | Mortgage Loan [Member]
Debt Instrument [Line Items]
Effective interest rate on the notes		6.01%	6.01%
NOVA Non-Core Portfolio [Member]
Debt Instrument [Line Items]
Disposition Date Of Property	[1]		Mar. 25, 2016
Mortgage and Other Indebtedness					$ 200
[1]	Consists of Van Buren Office Park, Herndon Corporate Center, Windsor at Battlefield, Reston Business Campus, Enterprise Center, Gateway Centre Manassas, Linden Business Center and Prosperity Business Center (collectively, the “NOVA Non-Core Portfolio”).

Debt - Summary of Company's Mor

Debt - Summary of Company's Mortgage Debt (Detail) - USD ($) $ in Thousands		Jul. 25, 2016	Sep. 30, 2016	Mar. 31, 2015	Sep. 30, 2016		Sep. 30, 2015	Mar. 31, 2016	Dec. 31, 2015	Aug. 04, 2011
Debt Instrument [Line Items]
Ownership Interest										97.00%
Line of Credit Facility, Increase (Decrease), Net			$ 8,000
Repayments of debt					$ 210,964		$ 226,155
Debt, Weighted Average Interest Rate			0.00%		0.00%
Debt, Weighted Average Interest Rate			2.00%		2.00%
Unamortized fair value adjustments			$ 31		$ 31				$ 172
Carrying amount of mortgages			$ 0		$ 0				213
LIBOR plus interest rate			1.35%
Gateway Centre Building One Debt [Member]
Debt Instrument [Line Items]
Mortgage and Other Indebtedness								$ 200
Contractual Interest Rate			7.35%		7.35%
Effective Interest Rate			5.88%		5.88%
Maturity Date			November 2016
Total Mortgage Debt	[1]		$ 0		$ 0				212
Effective Interest Rate			5.88%		5.88%
440 First Street, NW Construction Loan
Debt Instrument [Line Items]
Contractual Interest Rate			2.50%		2.50%
Contractual Interest Rate	[2]		LIBOR + 2.50%
Maturity Date			May 30, 2017
Percentage Of Principal Loan Amount And Unpaid Accrued Interest Recourse			50.00%		50.00%
Total Mortgage Debt	[3]		$ 32,216		$ 32,216				32,216
Storey Park [Member]
Debt Instrument [Line Items]
Ownership Interest			97.00%		97.00%
Contractual Interest Rate			2.50%		2.50%
Contractual Interest Rate	[2]		LIBOR + 2.50%
Maturity Date			October 2,016
Total Mortgage Debt	[4]		$ 0		$ 0				22,000
Hillside I and II
Debt Instrument [Line Items]
Contractual Interest Rate			0.00%		0.00%
Effective Interest Rate			0.00%		0.00%
Maturity Date			December 2,016
Total Mortgage Debt			$ 12,199		$ 12,199				12,368
Effective Interest Rate			0.00%		0.00%
Redland Corporate Center Buildings II & III
Debt Instrument [Line Items]
Contractual Interest Rate			0.00%		0.00%
Effective Interest Rate			0.00%		0.00%
Maturity Date			November 2,017
Total Mortgage Debt			$ 63,552		$ 63,552				64,543
Effective Interest Rate			0.00%		0.00%
840 First Street, NE
Debt Instrument [Line Items]
Contractual Interest Rate			0.00%		0.00%
Effective Interest Rate			0.00%		0.00%
Maturity Date			July 2,020
Total Mortgage Debt			$ 35,377		$ 35,377				35,888
Effective Interest Rate			0.00%		0.00%
Battlefield Corporate Center
Debt Instrument [Line Items]
Contractual Interest Rate			0.00%		0.00%
Effective Interest Rate			0.00%		0.00%
Maturity Date			November 2,020
Total Mortgage Debt			$ 3,397		$ 3,397				3,526
Effective Interest Rate			0.00%		0.00%
One thousand two hundred eleven Connecticut Avenue NW. [Member]
Debt Instrument [Line Items]
Contractual Interest Rate			0.00%		0.00%
Effective Interest Rate			0.00%		0.00%
Maturity Date			July 2,022
Total Mortgage Debt			$ 28,657		$ 28,657				29,110
Effective Interest Rate			0.00%		0.00%
1401 K Street, NW
Debt Instrument [Line Items]
Contractual Interest Rate			0.00%		0.00%
Effective Interest Rate			0.00%		0.00%
Maturity Date			June 1, 2023
Total Mortgage Debt			$ 35,726		$ 35,726				36,224
Effective Interest Rate			0.00%		0.00%
Eleven Dupont Circle [Member]
Debt Instrument [Line Items]
Contractual Interest Rate			0.00%		0.00%
Effective Interest Rate			0.00%		0.00%
Maturity Date			September 2,030
Total Mortgage Debt			$ 66,780		$ 66,780				66,780
Effective Interest Rate			0.00%		0.00%
Northern Virginia Development Project [Member]
Debt Instrument [Line Items]
Contractual Interest Rate			1.85%		1.85%
Contractual Interest Rate	[2]		LIBOR + 1.85%
Maturity Date			September 2,019
Total Mortgage Debt			$ 34,583		$ 34,583				9,176
Storey Park [Member]
Debt Instrument [Line Items]
Ownership Interest			97.00%		97.00%
Disposition Date Of Property		Jul. 25, 2016			Jul. 25, 2016	[5]
Total Mortgage Debt			$ 22,000		$ 22,000
Continuing Operations
Debt Instrument [Line Items]
Total Mortgage Debt			312,487		312,487				311,831
Unamortized fair value adjustments	[6]		(3,402)		(3,402)				(4,234)
Carrying amount of mortgages			$ 309,116		$ 309,116				307,769
Rumsey Center [Domain]
Debt Instrument [Line Items]
Disposition Date Of Property					Jul. 28, 2015
Richmond [Member]
Debt Instrument [Line Items]
Disposition Date Of Property	[7]			Mar. 19, 2015
Mortgages [Member]
Debt Instrument [Line Items]
Effective Interest Rate			3.54%		3.54%
Effective Interest Rate			3.54%		3.54%
Disposal Group, Held-for-sale, Not Discontinued Operations [Member]
Debt Instrument [Line Items]
Unamortized fair value adjustments			$ 0		$ 0				$ 1
[1]	The mortgage loan that encumbered Gateway Centre Manassas, which was included in the NOVA Non-Core Portfolio and sold on March 25, 2016, was classified within “Liabilities held-for-sale” on our December 31, 2015 consolidated balance sheet. In February 2016, we used $0.2 million in available cash to defease the outstanding balance of the mortgage loan.
[2]	At September 30, 2016, LIBOR was 0.53%.
[3]	This construction loan (the “440 First Street, NW Construction Loan”) is collateralized by 440 First Street, NW. In May 2016, we extended the maturity date by one year to May 30, 2017. We can repay all or a portion of the construction loan, without penalty, at any time during the term of the loan. At September 30, 2016, per the terms of the loan agreement, 50% of the outstanding principal balance and all of the outstanding accrued interest were recourse to us.
[4]	The Storey Park Land Loan encumbered the Storey Park land and was entered into by our 97% owned consolidated joint venture that owned Storey Park. On July 25, 2016, our consolidated joint venture sold Storey Park and the Storey Park Land Loan was concurrently repaid with proceeds from the sale.
[5]	1) This development site could have supported up to 712,000 rentable square feet.
[6]	In the first quarter of 2016, we adopted ASU 2015-03, which requires debt issuance costs to be presented on the balance sheet as a direct deduction from the carrying value of the respective debt liability and is applied on a retrospective basis.
[7]	Consists of Chesterfield Business Center, Hanover Business Center, Park Central, Virginia Technology Center and a three-acre parcel of undeveloped land (collectively, the “Richmond Portfolio”).

Debt - Additional Information (

Debt - Additional Information (Detail) $ in Thousands

Oct. 11, 2016USD ($)

Oct. 06, 2016USD ($)

Jul. 25, 2016

Sep. 30, 2016USD ($)TranchesRateshares

Jun. 30, 2016USD ($)Interest_Rate_Swaps

Sep. 30, 2015USD ($)

Sep. 30, 2016USD ($)shares

Sep. 30, 2015USD ($)

Oct. 28, 2016USD ($)

Sep. 30, 2016USD ($)

Sep. 30, 2016

Sep. 30, 2016Integer

Sep. 30, 2016Rate

Sep. 30, 2016Interest_Rate_Swaps

Jul. 06, 2016shares

Dec. 31, 2015USD ($)shares

Debt Instrument [Line Items]

Amount borrowed

$ 15,000

Basis spread over variable rate | Rate

1.35%

Recourse mortgage debt

$ 738,843

$ 724,038

Repayments of debt

$ 210,964

$ 226,155

Interest rate during period

1.90%

Maximum outstanding borrowings

$ 162,000

$ 217,000

204,000

$ 218,000

Weighted average interest rate

1.90%

Available capacity on the unsecured revolving credit facility

153,900

Annual commitment fee

0.15%

Number of interest rate swap agreements

9

9

9

Fixed effective interest rate

1.40%

Line of Credit Facility, Increase (Decrease), Net

$ 8,000

Principal payments from note receivable

$ 34,000

$ 29,720

Series A Preferred Shares, shares outstanding | shares

600,000

600,000

6,400,000

Debt Issuance Costs, Line of Credit Arrangements, Net

6,900

6,900

2,600

Unsecured Debt

299,374

$ 299,404

Unsecured Debt [Member]

Debt Instrument [Line Items]

Outstanding balance of three tranches

300,000

300,000

Repayments of debt

$ 10,000

Unsecured term loan

Debt Instrument [Line Items]

Number of tranches | Tranches

3

Unsecured Debt

300,000

Unsecured revolving credit facility

Debt Instrument [Line Items]

Unsecured revolving credit facility, net, effective interest rate of LIBOR plus 1.50%, maturing December 2019(3)

133,000

Repayments of debt

$ 37,000

Tranche A

Debt Instrument [Line Items]

Basis spread over variable rate

1.30%

Debt Instrument, Interest Rate, Increase (Decrease)

0.00%

Tranche A | Unsecured Debt [Member]

Debt Instrument [Line Items]

Outstanding balance of three tranches

100,000

100,000

Northern Virginia Development Project [Member]

Debt Instrument [Line Items]

Mortgage loans, net, effective interest rates ranging from 4.22% to 6.01%, maturing at various dates through September 2030(3)(4)

34,583

9,176

Debt Instrument, Interest Rate, Stated Percentage

1.85%

440 First Street, NW Construction Loan

Debt Instrument [Line Items]

Mortgage loans, net, effective interest rates ranging from 4.22% to 6.01%, maturing at various dates through September 2030(3)(4)

[1]

32,216

32,216

Debt Instrument, Interest Rate, Stated Percentage

2.50%

Percentage of outstanding principal

50.00%

Tranche C

Debt Instrument [Line Items]

Basis spread over variable rate

1.60%

Debt Instrument, Interest Rate, Increase (Decrease)

0.00%

Tranche C | Unsecured Debt [Member]

Debt Instrument [Line Items]

Outstanding balance of three tranches

100,000

$ 100,000

Interest Rate Swap

Debt Instrument [Line Items]

Expired Swap Percentage

1.80%

Expired Swap

60,000

Fixed effective interest rate

1.44%

0.00%

Amount on variable rate debt

$ 240,000

240,000

Unused lines of credit

Debt Instrument [Line Items]

Weighted average borrowings outstanding on unsecured revolving credit facility

$ 143,500

$ 164,200

$ 158,400

$ 168,900

NOVA Non-Core Portfolio

Debt Instrument [Line Items]

Disposition Date Of Property

[2]

Mar. 25, 2016

Proceeds from sale of properties

[2]

$ 90,501

Northern Virginia Development Project [Member]

Debt Instrument [Line Items]

Borrowing capacity of a construction loan

43,700

Nine Hundered And Fifty Street Nw [Member]

Debt Instrument [Line Items]

Principal payments from note receivable

34,000

$ 34,000

Storey Park [Member]

Debt Instrument [Line Items]

Disposition Date Of Property

Jul. 25, 2016

Jul. 25, 2016

[3]

Proceeds from sale of properties

$ 52,700

$ 52,659

[3]

Mortgage loans, net, effective interest rates ranging from 4.22% to 6.01%, maturing at various dates through September 2030(3)(4)

$ 22,000

Subsequent Event [Member]

Debt Instrument [Line Items]

Hillside Prepayment

Oct. 6, 2016

Amount borrowed

$ 11,000

Mortgage Loans on Real Estate, Cost of Mortgages Sold

$ 12,200

Subsequent Event [Member] | Unsecured revolving credit facility

Debt Instrument [Line Items]

Unsecured revolving credit facility, net, effective interest rate of LIBOR plus 1.50%, maturing December 2019(3)

$ 144,000

Series A Preferred Stock [Member]

Debt Instrument [Line Items]

Series A Preferred Shares, shares outstanding | shares

600,000

6,400,000

Maximum [Member]

Debt Instrument [Line Items]

Annual commitment fee

0.25%

[1]

This construction loan (the “440 First Street, NW Construction Loan”) is collateralized by 440 First Street, NW. In May 2016, we extended the maturity date by one year to May 30, 2017. We can repay all or a portion of the construction loan, without penalty, at any time during the term of the loan. At September 30, 2016, per the terms of the loan agreement, 50% of the outstanding principal balance and all of the outstanding accrued interest were recourse to us.

[2]

Consists of Van Buren Office Park, Herndon Corporate Center, Windsor at Battlefield, Reston Business Campus, Enterprise Center, Gateway Centre Manassas, Linden Business Center and Prosperity Business Center (collectively, the “NOVA Non-Core Portfolio”).

[3]

1) This development site could have supported up to 712,000 rentable square feet.

Debt - Unsecured Term Loan (Det

Debt - Unsecured Term Loan (Detail) - USD ($) $ in Thousands	3 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Debt Issuance Costs, Net	$ 6,700	$ 8,000
Deferred costs, net	$ (44,702)	(36,537)
Basis spread over variable rate	1.35%
Unsecured Debt	$ 299,374	299,404
Tranche A
Debt Instrument [Line Items]
Maturity Date	December 2,020
Basis spread over variable rate	1.30%
Tranche B
Debt Instrument [Line Items]
Maturity Date	June 2,021
Basis spread over variable rate	1.30%
Tranche C
Debt Instrument [Line Items]
Maturity Date	December 2,022
Basis spread over variable rate	1.60%
Unsecured Debt [Member]
Debt Instrument [Line Items]
Carrying value of the debt instruments	$ 300,000	300,000
Deferred costs, net	(626)	(596)
Unsecured Debt [Member] | Tranche A
Debt Instrument [Line Items]
Carrying value of the debt instruments	100,000	100,000
Unsecured Debt [Member] | Tranche B
Debt Instrument [Line Items]
Carrying value of the debt instruments	100,000	100,000
Unsecured Debt [Member] | Tranche C
Debt Instrument [Line Items]
Carrying value of the debt instruments	$ 100,000	$ 100,000

Derivative Instruments - Summar

Derivative Instruments - Summary of Interest Rate Swap Agreements (Detail) - USD ($) $ in Thousands		3 Months Ended
		Sep. 30, 2016	Sep. 30, 2016	Sep. 30, 2016	Jun. 30, 2016
Derivatives, Fair Value [Line Items]
Fixed LIBOR Interest Rate			1.40%
Interest Rate Swap
Derivatives, Fair Value [Line Items]
Notional Amount		$ 240,000			$ 240,000
Fixed LIBOR Interest Rate			1.44%	0.00%
Interest Rate Swap One
Derivatives, Fair Value [Line Items]
Maturity Date	[1]	Jul. 31, 2016
Interest Rate Swap Two
Derivatives, Fair Value [Line Items]
Maturity Date	[1]	Jul. 31, 2016
Interest Rate Swap Three
Derivatives, Fair Value [Line Items]
Maturity Date		Jul. 31, 2017
Notional Amount		$ 30,000
Interest Rate Contractual Component		LIBOR
Fixed LIBOR Interest Rate				0.00%
Interest Rate Swap Four
Derivatives, Fair Value [Line Items]
Maturity Date		Jul. 31, 2017
Notional Amount		$ 30,000
Interest Rate Contractual Component		LIBOR
Fixed LIBOR Interest Rate				0.00%
Interest Rate Swap Five
Derivatives, Fair Value [Line Items]
Maturity Date		Jul. 31, 2017
Notional Amount		$ 25,000
Interest Rate Contractual Component		LIBOR
Fixed LIBOR Interest Rate				0.00%
Interest Rate Swap Six
Derivatives, Fair Value [Line Items]
Maturity Date		Jul. 31, 2017
Notional Amount		$ 12,500
Interest Rate Contractual Component		LIBOR
Fixed LIBOR Interest Rate				0.00%
Interest Rate Swap Seven [Member]
Derivatives, Fair Value [Line Items]
Maturity Date		Jul. 31, 2017
Notional Amount		$ 50,000
Interest Rate Contractual Component		LIBOR
Fixed LIBOR Interest Rate				0.00%
Interest Rate Swap Eight [Member]
Derivatives, Fair Value [Line Items]
Maturity Date		Jul. 31, 2018
Notional Amount		$ 12,500
Interest Rate Contractual Component		LIBOR
Fixed LIBOR Interest Rate				0.00%
Interest Rate Swap Nine [Member]
Derivatives, Fair Value [Line Items]
Maturity Date		Jul. 31, 2018
Notional Amount		$ 30,000
Interest Rate Contractual Component		LIBOR
Fixed LIBOR Interest Rate				0.00%
Interest Rate Swap Ten [Member]
Derivatives, Fair Value [Line Items]
Maturity Date		Jul. 31, 2018
Notional Amount		$ 25,000
Interest Rate Contractual Component		LIBOR
Fixed LIBOR Interest Rate				0.00%
Interest Rate Swap Eleven
Derivatives, Fair Value [Line Items]
Maturity Date		Jul. 31, 2018
Notional Amount		$ 25,000
Interest Rate Contractual Component		LIBOR
Fixed LIBOR Interest Rate				0.00%
[1]	{F|ahBzfndlYmZpbGluZ3MtaHJkcmoLEgZYTUxEb2MiXlhCUkxEb2NHZW5JbmZvOmZmODgyZmU4OWY3ZDRkMmFiMzk2ZWExOWY0YmNhMThifFRleHRTZWxlY3Rpb246NDVFOUY2MEYyN0FCNTZGRjg2MzJBMTIwRkU4NDNENEMM}

Derivative Instruments - Additi

Derivative Instruments - Additional Information (Detail) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016USD ($)	Sep. 30, 2015USD ($)	Sep. 30, 2016USD ($)	Sep. 30, 2015USD ($)	Sep. 30, 2016	Sep. 30, 2016Integer	Sep. 30, 2016Rate	Sep. 30, 2016Interest_Rate_Swaps	Jun. 30, 2016USD ($)Interest_Rate_Swaps
Derivatives, Fair Value [Line Items]
Number of interest rate swap agreements						9		9	9
Fixed effective interest rate					1.40%
Interest Rate Swap
Derivatives, Fair Value [Line Items]
Expired Swap	$ 60,000		$ 60,000
Fixed effective interest rate					1.44%		0.00%
Amount on variable rate debt	240,000		240,000						$ 240,000
Interest Rate Swap | Interest Expense
Derivatives, Fair Value [Line Items]
Accumulated other comprehensive loss reclassified as an increase in interest expense	$ 600	$ 1,000	2,300	$ 3,000
Estimated accumulated other comprehensive loss reclassified as an increase in interest expense over the following twelve months			$ 1,600

Fair Value Measurements - Fair

Fair Value Measurements - Fair Value of Assets and Liabilities (Detail) - Recurring Measurements - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Recurring Measurements:
Derivative instrument-swap liabilities	$ 2,045	$ 2,491
Assets, Fair Value Disclosure, Nonrecurring		104,625
Level 1
Recurring Measurements:
Derivative instrument-swap assets		0
Derivative instrument-swap liabilities	0	0
Level 2
Recurring Measurements:
Derivative instrument-swap assets		90,625
Derivative instrument-swap liabilities	2,045	2,491
Level 3
Recurring Measurements:
Derivative instrument-swap assets		14,000
Derivative instrument-swap liabilities	$ 0	$ 0

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) $ in Thousands		3 Months Ended					9 Months Ended
		Sep. 30, 2016USD ($)	Jun. 30, 2016USD ($)Interest_Rate_Swapssnapshot	Mar. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Sep. 30, 2015USD ($)	Sep. 30, 2016USD ($)	Sep. 30, 2015USD ($)	Sep. 30, 2016Integer	Sep. 30, 2016Interest_Rate_Swaps
Derivatives, Fair Value [Line Items]
Impairment of rental property							$ 2,772	$ 0
(Gain) loss on sale of rental property		$ 0		$ (1,200)		$ 3,384	(1,155)	$ 3,384
Number of Interest Rate Derivatives Held			9						9	9
Debt Issuance Costs, Net		6,700			$ 8,000		6,700
Proceeds From Note Receivable, Date			Jun. 2, 2016
Interest Rate Swap
Derivatives, Fair Value [Line Items]
Notional Amount		$ 240,000	$ 240,000				$ 240,000
Minimum number of daily snapshot used for valuation of interest rate swap agreements | snapshot			7,500
NOVA Non-Core Portfolio [Member]
Derivatives, Fair Value [Line Items]
Disposition Date Of Property	[1]						Mar. 25, 2016
Mortgage and Other Indebtedness					200
Impairment of rental property					26,900
One Fair Oaks [Member]
Derivatives, Fair Value [Line Items]
Impairment of rental property					$ 33,900
[1]	Consists of Van Buren Office Park, Herndon Corporate Center, Windsor at Battlefield, Reston Business Campus, Enterprise Center, Gateway Centre Manassas, Linden Business Center and Prosperity Business Center (collectively, the “NOVA Non-Core Portfolio”).

Fair Value Measurements - Fai59

Fair Value Measurements - Fair Value of Debt Instruments (Detail) $ in Thousands		Sep. 30, 2016USD ($)ft²	Dec. 31, 2015USD ($)		Sep. 30, 2015ft²	[1]
Financial Assets:
Carrying value of notes receivable		$ 0	$ 34,000
Financial Liabilities:
Area of real estate property | ft²		6,712,947			7,842,393
Carrying Value
Financial Assets:
Carrying value of notes receivable		$ 0	34,000
Financial Liabilities:
Carrying value of the debt instruments		745,517	732,216
Carrying Value | Mortgages [Member]
Financial Liabilities:
Carrying value of the debt instruments		312,517	312,216	[2]
Carrying Value | Unsecured Debt [Member]
Financial Liabilities:
Carrying value of the debt instruments	[2]	300,000	300,000
Carrying Value | Unsecured revolving credit facility
Financial Liabilities:
Carrying value of the debt instruments	[2]	133,000	120,000
Fair Value
Financial Assets:
Fair value of notes receivable		0	34,000
Financial Liabilities:
Fair value of the debt instruments		757,145	718,541
Fair Value | Mortgages [Member]
Financial Liabilities:
Fair value of the debt instruments		324,145	298,541
Fair Value | Unsecured Debt [Member]
Financial Liabilities:
Fair value of the debt instruments		300,000	300,000
Fair Value | Unsecured revolving credit facility
Financial Liabilities:
Fair value of the debt instruments		$ 133,000	$ 120,000
[1]	Total assets include our investment in properties that are owned through joint ventures that are not consolidated within our condensed consolidated financial statements. For more information on our unconsolidated investments, including location within our reportable segments, see note 6, Investment in Affiliates. Corporate assets not allocated to any of our reportable segments totaled $18,723 and $42,988 at September 30, 2016 and 2015, respectively.
[2]	In the first quarter of 2016, we adopted ASU 2015-03, which requires debt issuance costs to be presented in the balance sheet as a direct deduction from the carrying value of the respective debt liability and which is applied on a retrospective basis. The debt balances exclude a combined total of $6.7 million and $8.0 million of unamortized deferred financing costs at September 30, 2016 and December 31, 2015, respectively.

Equity - Additional Information

Equity - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions

Nov. 15, 2016

Nov. 08, 2016

Oct. 24, 2016

Aug. 15, 2016

Aug. 08, 2016

Jul. 25, 2016

Jul. 06, 2016

Jan. 19, 2016

Apr. 27, 2016

Sep. 30, 2016

Jun. 30, 2016

Mar. 31, 2016

Sep. 30, 2016

Dec. 31, 2015

Jul. 31, 2015

Dividends Payable [Line Items]

Series A Preferred Shares, shares outstanding

600,000

600,000

6,400,000

Dividend declared date

Jul. 25, 2016

Series A Preferred Shares

Dividends Payable [Line Items]

Series A Preferred Shares, shares outstanding

600,000

6,400,000

Stock Redeemed or Called During Period, Shares

600,000

3,600,000

2,200,000

6,400,000

Preferred Stock, Redemption Price Per Share

$ 25

$ 25

$ 25

Preferred Stock, Redemption Date

Jul. 6, 2016

Jan. 19, 2016

Apr. 27, 2016

Common Shares

Dividends Payable [Line Items]

Stock Repurchase Program, Number of Shares Authorized to be Repurchased

5,000,000

Common share dividend per share declared

$ 0.10

Common share dividend per share annualized

$ 0.40

Dividend paid date

Aug. 15, 2016

Dividend record date

Aug. 8, 2016

Stock Repurchase Program Expiration Date

Jul. 31, 2016

Stock Repurchased and Retired During Period, Shares

924,198

Stock Repurchased and Retired During Period, Weighted Average Share Price

$ 10.99

Stock Repurchased and Retired During Period, Value

$ 10.2

Subsequent Event [Member]

Dividends Payable [Line Items]

Dividend declared date

Oct. 24, 2016

Subsequent Event [Member] | Common Shares

Dividends Payable [Line Items]

Common share dividend per share declared

$ 0.10

Common share dividend per share annualized

$ 0.40

Dividend paid date

Nov. 15, 2016

Dividend record date

Nov. 8, 2016

Equity - Company's Allocation B

Equity - Company's Allocation Between Non-controlling Interests (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015	Dec. 31, 2014
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Noncontrolling interests in a consolidated partnership	$ 0		$ 0		$ 800
Total equity	444,823	$ 672,329	444,823	$ 672,329	625,328	$ 710,905
Net Income (Loss) Attributable to Parent	2,135	3,959	579	5,154
Net income (loss)			506	5,151
Changes in ownership, net			(155,790)	3,289
Distributions to owners			(25,653)	(35,821)
Other comprehensive income			432	(1,015)
Increase (Decrease) in Temporary Equity [Roll Forward]
Beginning Balance, Redeemable noncontrolling interests			28,813	33,332
Net income (loss), Redeemable noncontrolling interests			(357)	(186)
Change in ownership, net, Redeemable noncontrolling interests			(1,412)	(1,257)
Distributions to owners, Redeemable noncontrolling interests			(909)	(1,181)
Other comprehensive income, Redeemable noncontrolling interests			20	(45)
Ending Balance, Redeemable noncontrolling interests	26,155	30,663	26,155	30,663
Repurchase of Common Shares			0	(10,180)
First Potomac Realty Trust
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance			624,528	710,007
Net Income (Loss) Attributable to Parent			579	5,154
Changes in ownership, net			(155,790)	3,289
Distributions to owners			(24,926)	(35,725)
Other comprehensive income			432	(1,015)
Ending Balance	444,823	671,530	444,823	671,530
Increase (Decrease) in Temporary Equity [Roll Forward]
Repurchase of Common Shares				(10,180)
Non-redeemable Noncontrolling Interests
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Noncontrolling interests in a consolidated partnership	$ 0	$ 799	0	799	$ 800	$ 898
Net income (loss)			(73)	(3)
Changes in ownership, net			0	0
Distributions to owners			(727)	(96)
Other comprehensive income			$ 0	0
Increase (Decrease) in Temporary Equity [Roll Forward]
Repurchase of Common Shares				$ 0

Equity - Company's Accumulated

Equity - Company's Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Equity [Abstract]
Beginning balance			$ (2,360)	$ (3,268)
Net unrealized gain (loss) on derivative instruments			452	(1,060)
Ending balance	$ (1,928)	$ (4,283)	(1,928)	(4,283)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax, Portion Attributable to Noncontrolling Interest	$ 48	$ (31)	$ 20	$ (45)

Noncontrolling Interests - Addi

Noncontrolling Interests - Additional Information (Detail) - USD ($) $ in Millions	Jul. 25, 2016	Sep. 30, 2016	Sep. 30, 2016		Dec. 31, 2015	Sep. 30, 2015	Aug. 04, 2011
Business Acquisition [Line Items]
Cost to acquire all of the outstanding common Operating Partnership units not owned by the Company		$ 23.6	$ 23.6
Fair value adjustment, cost basis		$ 3.2	$ 3.2		$ 4
Outstanding Operating Partnership units not owned by the Company			2,577,478
Operating Partnership units not owned by Company		0.00%
Common operating partnership units redeemed for cash		41,591	41,591			11,508
Common operating partnership units redeemed for common shares		0	0
Ownership Interest							97.00%
Storey Park [Member]
Business Acquisition [Line Items]
Ownership Interest		97.00%	97.00%
Disposition Date Of Property	Jul. 25, 2016		Jul. 25, 2016	[1]
[1]	1) This development site could have supported up to 712,000 rentable square feet.

Share-Based Payments - Addition

Share-Based Payments - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Payment Award, Shares Purchased for Award	181,357
RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense associated with trustee share based awards	$ 0.6	$ 0.7	$ 1.5	$ 2
Unrecognized compensation cost related to non-vested shares	$ (5.5)		$ (5.5)
Non-Vested Share Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average period for recognition of non-vested shares	3 years 4 months
Executive Officer [Member] | RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Payment Award, Shares Purchased for Award	181,357
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate	25.00%		0.48%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate			24.10%
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate	300.00%		0.96%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate			26.20%

Share-Based Payments - Summary

Share-Based Payments - Summary of Company's Non-vested Share Awards (Detail)	3 Months Ended
	Sep. 30, 2016$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Non-vested Shares, Beginning Balance | shares	532,069
Non-vested Shares, Granted | shares	181,357
Non-vested Shares, Ending Balance | shares	713,426
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Weighted Average Grant Date Fair Value, Beginning Balance | $ / shares	$ 10.31
Weighted Average Grant Date Fair Value, Granted | $ / shares	8.59
Weighted Average Grant Date Fair Value, Ending Balance | $ / shares	$ 9.87

Segment Information - Additiona

Segment Information - Additional Information (Detail)	3 Months Ended
	Sep. 30, 2016segment
Segment Reporting [Abstract]
Number of Reportable Segments	4

Segment Information - Summary o

Segment Information - Summary of Segment Information (Detail) $ in Thousands	Jul. 25, 2016	Sep. 30, 2016USD ($)ft²Integerbuilding		Sep. 30, 2015USD ($)ft²Integer		Sep. 30, 2016USD ($)ft²Integerbuilding		Sep. 30, 2015USD ($)ft²Integer		Dec. 31, 2015USD ($)
Segment Reporting Information [Line Items]
Number of buildings | Integer		74		108	[1]	74		108	[1]
Square feet | ft²		6,712,947		7,842,393	[1]	6,712,947		7,842,393	[1]
Total revenues		$ 40,172		$ 42,854		$ 121,361		$ 129,741
Property operating expense		(9,500)		(10,901)		(29,580)		(34,676)
Real estate taxes and insurance		(4,755)		(4,815)		(14,891)		(14,668)
Total property operating income		25,917		27,138		76,890		80,397
Depreciation and amortization expense		(13,928)		(16,758)		(44,075)		(49,909)
General and administrative		(4,112)		(4,605)		(12,995)		(15,110)
Impairment of Real Estate						(2,772)		0
Other expenses		(5,635)		(1,778)		(16,899)		(9,806)
Loss from discontinued operations		0		0		0		(607)
Net income		2,242		3,997		149		4,965
Total assets		1,270,670	[1]	1,519,609	[1],[2]	1,270,670	[1]	1,519,609	[1],[2]	$ 1,442,406
Capital expenditure		7,168		18,521	[3]	48,707		49,846	[3]
Debt Issuance Costs, Line of Credit Arrangements, Net		2,600		6,900		2,600		6,900
Capital expenditures for corporate assets not allocated to any reportable segments		234		104		426		413
Corporate assets not allocated to any reportable segments		$ 18,723		$ 42,988		$ 18,723		$ 42,988
Washington, D.C.
Segment Reporting Information [Line Items]
Number of buildings		6		6	[1]	6		6	[1]
Square feet | ft²		917,453		915,692	[1]	917,453		915,692	[1]
Total revenues		$ 11,856		$ 11,337		$ 34,725		$ 33,522
Property operating expense		(3,065)		(2,962)		(8,596)		(9,088)
Real estate taxes and insurance		(2,266)		(2,015)		(7,060)		(5,994)
Total property operating income		6,525		6,360		19,069		18,440
Total assets		450,697	[1]	512,245		450,697	[1]	512,245
Capital expenditure		$ 3,251		$ 2,440	[3]	$ 11,449		$ 9,859	[3]
Maryland
Segment Reporting Information [Line Items]
Number of buildings		34		34	[1]	34		34	[1]
Square feet | ft²		1,885,786		1,884,741	[1]	1,885,786		1,884,741	[1]
Total revenues		$ 11,043		$ 10,575		$ 33,531		$ 33,315
Property operating expense		(2,306)		(2,467)		(7,636)		(9,129)
Real estate taxes and insurance		(994)		(893)		(2,883)		(2,681)
Total property operating income		7,743		7,215		23,012		21,505
Total assets		336,110	[1]	344,073		336,110	[1]	344,073
Capital expenditure		$ 1,478		$ 2,649	[3]	$ 4,839		$ 6,965	[3]
Northern Virginia
Segment Reporting Information [Line Items]
Number of buildings		15		49	[1]	15		49	[1]
Square feet | ft²		1,885,850		3,020,293	[1]	1,885,850		3,020,293	[1]
Total revenues		$ 9,649		$ 13,715		$ 30,662		$ 41,529
Property operating expense		(2,061)		(3,347)		(7,575)		(10,603)
Real estate taxes and insurance		(864)		(1,285)		(3,104)		(4,178)
Total property operating income		6,724		9,083		19,983		26,748
Total assets		$ 301,706	[1]	452,421		301,706	[1]	452,421
Capital expenditure				$ 11,309	[3]	$ 29,739		$ 27,190	[3]
Southern Virginia
Segment Reporting Information [Line Items]
Number of buildings		19		19	[1]	19		19	[1]
Square feet | ft²		2,023,858		2,021,667	[1]	2,023,858		2,021,667	[1]
Total revenues		$ 7,624		$ 7,227		$ 22,443		$ 21,375
Property operating expense		(2,068)		(2,125)		(5,773)		(5,856)
Real estate taxes and insurance		(631)		(622)		(1,844)		(1,815)
Total property operating income		4,925		4,480		14,826		13,704
Total assets		163,434	[1]	167,882		163,434	[1]	167,882
Capital expenditure		520		$ 2,019	[3]	$ 2,254		$ 5,419	[3]
Northern Virginia
Segment Reporting Information [Line Items]
Capital expenditure		$ 1,685
Storey Park [Member]
Segment Reporting Information [Line Items]
Disposition Date Of Property	Jul. 25, 2016
[1]	Total assets include our investment in properties that are owned through joint ventures that are not consolidated within our condensed consolidated financial statements. For more information on our unconsolidated investments, including location within our reportable segments, see note 6, Investment in Affiliates. Corporate assets not allocated to any of our reportable segments totaled $18,723 and $42,988 at September 30, 2016 and 2015, respectively.
[2]	Total assets at September 30, 2015 have been restated to exclude a total of $6.9 million of unamortized deferred financing costs that are now deducted from the respective debt liability in accordance with ASU 2015-03, which we adopted in the first quarter of 2016.
[3]	Capital expenditures for corporate assets not allocated to any of our reportable segments totaled $234 and $104 for the three months ended September 30, 2016 and 2015, respectively, and $426 and $413 for the nine months ended September 30, 2016 and 2015, respectively.

Uncategorized Items - fpo-20160

Label	Element	Value
Interest Paid, Net	us-gaap_InterestPaidNet	$ 19,078,000
Interest Paid, Net	us-gaap_InterestPaidNet	18,444,000
Payment Of Cost Of Construction	fpo_PaymentOfCostOfConstruction	640,000
Payment Of Cost Of Construction	fpo_PaymentOfCostOfConstruction	(5,465,000)
Payments For Acquisition Of Rental Property Furniture Fixtures And Equipment	fpo_PaymentsForAcquisitionOfRentalPropertyFurnitureFixturesAndEquipment	(2,034,000)
Payments For Acquisition Of Rental Property Furniture Fixtures And Equipment	fpo_PaymentsForAcquisitionOfRentalPropertyFurnitureFixturesAndEquipment	(1,556,000)
Change In Fair Value Of Outstanding Common Operating Partnership Units	fpo_ChangeInFairValueOfOutstandingCommonOperatingPartnershipUnits	(1,123,000)
Change In Fair Value Of Outstanding Common Operating Partnership Units	fpo_ChangeInFairValueOfOutstandingCommonOperatingPartnershipUnits	$ (1,069,000)