Gladstone Commercial (GOOD) 10-Q 30 Jul 18 2018 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2018	Jul. 30, 2018
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q2
Trading Symbol	GOOD
Entity Registrant Name	GLADSTONE COMMERCIAL CORP
Entity Central Index Key	1,234,006
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		28,663,687

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands		Jun. 30, 2018	Dec. 31, 2017
ASSETS
Real estate, at cost		$ 905,349	$ 893,853
Less: accumulated depreciation		163,349	149,417
Total real estate, net		742,000	744,436
Lease intangibles, net		111,978	118,927
Real estate and related assets held for sale, net		1,436	9,046
Cash and cash equivalents		4,552	6,683
Restricted cash		2,738	2,397
Funds held in escrow		9,520	9,369
Deferred rent receivable, net		34,280	33,333
Other assets		5,504	4,263
TOTAL ASSETS		912,008	928,454
LIABILITIES
Mortgage notes payable, net	[1]	435,073	447,380
Borrowings under Revolver, net		32,808	20,715
Borrowings under Term Loan, net		74,580	74,532
Deferred rent liability, net		15,278	16,250
Asset retirement obligation		2,814	3,051
Accounts payable and accrued expenses		5,606	7,339
Liabilities related to assets held for sale, net		297	114
Due to Adviser and Administrator	[1]	2,352	2,289
Other liabilities		6,386	6,554
TOTAL LIABILITIES		575,194	578,224
Commitments and contingencies	[2]
MEZZANINE EQUITY
Series D redeemable preferred stock, net, par value $0.001 per share; $25 per share liquidation preference; 6,000,000 shares authorized; and 3,509,555 and 3,421,853 shares issued and outstanding at June 30, 2018 and December 31, 2017, respectively	[3]	85,598	83,432
TOTAL MEZZANINE EQUITY		85,598	83,432
STOCKHOLDERS’ EQUITY
Series A and B redeemable preferred stock, par value $0.001 per share; $25 per share liquidation preference; 5,350,000 shares authorized and 2,264,000 shares issued and outstanding at June 30, 2018 and December 31, 2017, respectively (3)		2	2
Senior common stock, par value $0.001 per share; 950,000 and 4,450,000 shares authorized; and 891,118 and 904,819 shares issued and outstanding at June 30, 2018 and December 31, 2017, respectively (3)		1	1
Common stock, par value $0.001 per share, 87,700,000 and 34,200,000 shares authorized and 28,578,654 and 28,384,016 shares issued and outstanding at June 30, 2018 and December 31, 2017, respectively (3)		29	28
Additional paid in capital		538,276	534,790
Accumulated other comprehensive income		818	35
Distributions in excess of accumulated earnings		(287,910)	(268,058)
TOTAL STOCKHOLDERS' EQUITY		251,216	266,798
TOTAL LIABILITIES, MEZZANINE EQUITY AND STOCKHOLDERS’ EQUITY		$ 912,008	$ 928,454
[1]	Refer to Note 2 “Related-Party Transactions”
[2]	Refer to Note 7 “Commitments and Contingencies”
[3]	Refer to Note 8 “Stockholders’ and Mezzanine Equity”

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Jun. 30, 2018	Dec. 31, 2017
Senior common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Senior common stock, shares authorized	950,000	4,450,000
Senior common stock, shares issued	891,118	904,819
Senior common stock, shares outstanding	891,118	904,819
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized	87,700,000	34,200,000
Common stock, shares issued	28,578,654	28,384,016
Common stock, shares outstanding	28,578,654	28,384,016
Series D Preferred Stock
Mezzanine equity, par value (in dollars per share)	$ 0.001	$ 0.001
Mezzanine equity, liquidation preference (in dollars per share)	$ 25	$ 25
Mezzanine equity, shares authorized	6,000,000	6,000,000
Mezzanine equity, shares issued	3,509,555	3,421,853
Mezzanine equity, shares outstanding	3,509,555	3,421,853
Series A and B Preferred Stock
Redeemable preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Redeemable preferred stock, liquidation preference (in dollars per share)	$ 25	$ 25
Redeemable preferred stock, shares authorized	5,350,000	5,350,000
Redeemable preferred stock, shares issued	2,264,000	2,264,000
Redeemable preferred stock, shares outstanding	2,264,000	2,264,000

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Other Comprehensive Income - USD ($)		3 Months Ended		6 Months Ended
		Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Operating revenues
Rental revenue		$ 25,692,000	$ 22,478,000	$ 51,283,000	$ 44,438,000
Tenant recovery revenue		901,000	389,000	1,663,000	744,000
Total operating revenues		26,593,000	22,867,000	52,946,000	45,182,000
Operating expenses
Depreciation and amortization		11,773,000	9,926,000	23,358,000	19,845,000
Property operating expenses		2,816,000	1,505,000	5,609,000	2,884,000
Base management fee	[1]	1,260,000	1,207,000	2,556,000	2,387,000
Incentive fee	[1]	733,000	551,000	1,429,000	1,120,000
Administration fee	[1]	360,000	340,000	747,000	700,000
General and administrative		600,000	575,000	1,245,000	1,127,000
Impairment charge		0	253,000	0	3,999,000
Total operating expenses		17,542,000	14,357,000	34,944,000	32,062,000
Other (expense) income
Interest expense		(6,531,000)	(5,944,000)	(12,744,000)	(12,103,000)
(Loss) gain on sale of real estate, net		0	(1,914,000)	1,844,000	3,992,000
Other income		5,000	9,000	28,000	11,000
Total other expense, net		(6,526,000)	(7,849,000)	(10,872,000)	(8,100,000)
Net income		2,525,000	661,000	7,130,000	5,020,000
Distributions attributable to Series A, B and D preferred stock		(2,609,000)	(2,437,000)	(5,191,000)	(4,810,000)
Distributions attributable to senior common stock		(233,000)	(249,000)	(465,000)	(497,000)
Net (loss) income (attributable) available to common stockholders		$ (317,000)	$ (2,025,000)	$ 1,474,000	$ (287,000)
(Loss) earnings per weighted average share of common stock - basic & diluted
Loss attributable to common shareholders (in dollars per share)		$ (0.01)	$ (0.08)	$ 0.05	$ (0.01)
Weighted average shares of common stock outstanding
Basic and Diluted (in shares)		28,437,852	25,276,824	28,429,470	25,121,239
Distributions declared per common share (in dollars per share)		$ 0.375	$ 0.375	$ 0.75	$ 0.75
Earnings per weighted average share of senior common stock (in dollars per share)		$ 0.26	$ 0.26	$ 0.52	$ 0.52
Weighted average shares of senior common stock outstanding - basic (in shares)		891,428	950,841	893,315	954,590
Comprehensive income
Change in unrealized gain related to interest rate hedging instruments, net		$ 289,000	$ 179,000	$ 783,000	$ 179,000
Other Comprehensive income		289,000	179,000	783,000	179,000
Net income		2,525,000	661,000	7,130,000	5,020,000
Comprehensive income		$ 2,814,000	$ 840,000	$ 7,913,000	$ 5,199,000
[1]	Refer to Note 2 “Related-Party Transactions”

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Cash Flows - USD ($)	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Cash flows from operating activities:
Net income	$ 7,130,000	$ 5,020,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	23,358,000	19,845,000
Impairment charge	0	3,999,000
Gain on sale of real estate, net	(1,844,000)	(3,992,000)
Amortization of deferred financing costs	758,000	854,000
Amortization of deferred rent asset and liability, net	(522,000)	(412,000)
Amortization of discount and premium on assumed debt	(53,000)	(60,000)
Asset retirement obligation expense	60,000	65,000
Operating changes in assets and liabilities
Increase in other assets	(458,000)	(1,615,000)
Increase in deferred rent receivable	(1,335,000)	(1,549,000)
Decrease in accounts payable, accrued expenses, and amount due Adviser and Administrator	(206,000)	(837,000)
(Decrease) increase in other liabilities	(511,000)	392,000
Tenant inducement payments	0	(122,000)
Leasing commissions paid	(382,000)	(168,000)
Net cash provided by operating activities	25,995,000	21,420,000
Cash flows from investing activities:
Acquisition of real estate and related intangible assets	(14,341,000)	(4,518,000)
Improvements of existing real estate	(2,169,000)	(6,796,000)
Proceeds from sale of real estate	10,773,000	25,290,000
Receipts from lenders for funds held in escrow	1,097,000	3,320,000
Payments to lenders for funds held in escrow	(1,248,000)	(1,119,000)
Receipts from tenants for reserves	1,544,000	1,349,000
Payments to tenants from reserves	(1,175,000)	(1,255,000)
Deposits on future acquisitions	(340,000)	(1,650,000)
Deposits applied against acquisition of real estate investments	300,000	0
Net cash (used in) provided by investing activities	(5,559,000)	14,621,000
Cash flows from financing activities:
Proceeds from issuance of equity	5,779,000	25,178,000
Offering costs paid	(94,000)	(422,000)
Retirement of senior common stock	(34,000)	0
Borrowings under mortgage notes payable	9,380,000	6,700,000
Payments for deferred financing costs	(253,000)	(414,000)
Principal repayments on mortgage notes payable	(21,998,000)	(40,573,000)
Borrowings from revolving credit facility	50,400,000	50,000,000
Repayments on revolving credit facility	(38,400,000)	(51,900,000)
Decrease in security deposits	(26,000)	(348,000)
Distributions paid for common, senior common and preferred stock	(26,980,000)	(24,159,000)
Net cash used in financing activities	(22,226,000)	(35,938,000)
Net (decrease) increase in cash, cash equivalents, and restricted cash	(1,790,000)	103,000
Cash, cash equivalents, and restricted cash at beginning of period	9,080,000	7,688,000
Cash, cash equivalents, and restricted cash at end of period	4,552,000	5,014,000
NON-CASH INVESTING AND FINANCING INFORMATION
Tenant funded fixed asset improvements	27,000	1,571,000
Assumed mortgage in connection with acquisition	0	11,179,000
Assumed interest rate swap fair market value	0	42,000
Unrealized gain related to interest rate hedging instruments, net	783,000	179,000
Capital improvements included in accounts payable and accrued expenses	$ 31,000	$ 2,031,000

Condensed Consolidated Stateme6

Condensed Consolidated Statements of Cash Flows - Schedule of Cash, Cash Equivalents and Restricted Cash - USD ($) $ in Thousands	Jun. 30, 2018	Jun. 30, 2017
Statement of Cash Flows [Abstract]
Cash and cash equivalents	$ 4,552	$ 5,014
Restricted cash	2,738	2,777
Total cash, cash equivalents, and restricted cash shown in the condensed consolidated statement of cash flows	$ 7,290	$ 7,791

Organization, Basis of Presenta

Organization, Basis of Presentation and Significant Accounting Policies	6 Months Ended
	Jun. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization, Basis of Presentation and Significant Accounting Policies	Organization, Basis of Presentation and Significant Accounting Policies Gladstone Commercial Corporation is a real estate investment trust (“REIT”) that was incorporated under the General Corporation Law of the State of Maryland on February 14, 2003. We focus on acquiring, owning and managing primarily office and industrial properties. On a selective basis, we may make long term industrial and commercial mortgage loans; however, we do not have any mortgage loans currently outstanding. Subject to certain restrictions and limitations, our business is managed by Gladstone Management Corporation, a Delaware corporation (the “Adviser”), and administrative services are provided by Gladstone Administration, LLC, a Delaware limited liability company (the “Administrator”), each pursuant to a contractual arrangement with us. Our Adviser and Administrator collectively employ all of our personnel and pay their salaries, benefits, and general expenses directly. Gladstone Commercial Corporation conducts substantially all of its operations through a subsidiary, Gladstone Commercial Limited Partnership, a Delaware limited partnership (the “Operating Partnership”). All further references herein to “we,” “our,” “us” and the “Company” mean Gladstone Commercial Corporation and its consolidated subsidiaries, except where it is made clear that the term means only Gladstone Commercial Corporation. Interim Financial Information Our interim financial statements are prepared in accordance with generally accepted accounting principles (“GAAP”) for interim financial information and pursuant to the requirements for reporting on Form 10-Q and in accordance with Article 10 of Regulation S-X. Accordingly, certain disclosures accompanying annual financial statements prepared in accordance with GAAP are omitted. The year-end balance sheet data presented herein was derived from audited financial statements, but does not include all disclosures required by GAAP. In the opinion of our management, all adjustments, consisting solely of normal recurring accruals, necessary for the fair statement of financial statements for the interim period, have been included. The interim financial statements and notes thereto should be read in conjunction with the financial statements and notes thereto included in our Annual Report on Form 10-K for the year ended December 31, 2017 , as filed with the U.S. Securities and Exchange Commission on February 14, 2018 . The results of operations for the three and six months ended June 30, 2018 are not necessarily indicative of the results that may be expected for other interim periods or for the full fiscal year. Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting periods. Actual results could materially differ from those estimates. Critical Accounting Policies In preparation of our financial statements in accordance with GAAP, we apply certain critical accounting policies which require management to make judgments that are subjective in nature to make certain estimates and assumptions. Application of our accounting policies involves the exercise of judgment regarding the use of assumptions as to future uncertainties, and as a result, actual results could materially differ from these estimates. A summary of all of our significant accounting policies is provided in Note 1 to our consolidated financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2017 . There were no material changes to our critical accounting policies during the three and six months ended June 30, 2018 . Recently Issued Accounting Pronouncements In May 2014, the Financial Accounting Standards Board (“FASB”) issued guidance regarding the recognition of revenue from contracts with customers. Under this guidance, an entity will recognize revenue to depict the transfer of goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. This guidance also requires improved disclosures regarding the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers. We adopted this guidance for our annual and interim periods beginning January 1, 2018 and will use the modified retrospective method, under which the cumulative effect of initially applying the guidance is recognized at the date of initial application. Our adoption of this guidance did not have a material impact on our consolidated financial statements. Further, as discussed below, once the new guidance regarding the principles for the recognition measurement, presentation and disclosure of leases goes into effect on January 1, 2019, we expect the new revenue standard will apply to executory costs and other components of revenue due under leases that are deemed to be non-lease components (examples include common area maintenance and provision of utilities), even when the revenue for such activities is not separately stipulated in the lease. Revenue from these non-lease components, which were previously recognized on a straight-line basis under current lease guidance, would be recognized under the new revenue guidance as the related services are delivered. As a result, while our total revenue recognized over the lease term would not differ under the new guidance, the revenue recognition pattern could be different. We are currently evaluating the impact of revenue recognition from the adoption of the lease standard on our consolidated financial statements. In February 2016, the FASB issued Accounting Standards Update (“ASU”) 2016-02, “Leases: Amendments to the FASB Accounting Standards Codification” (“ASU 2016-02”). The new standard requires lessees to apply a dual approach, classifying leases as either finance or operating leases based on the principle of whether or not the lease is effectively a financed purchase of the leased asset by the lessee. This classification will determine whether lease expense is recognized based on an effective interest method or on a straight line basis over the term of the lease, respectively. A lessee is also required to record a right-of-use asset and a lease liability for all leases with a term of greater than 12 months regardless of their classification. Leases with a term of 12 months or less will be accounted for similar to existing guidance for operating leases today. The new standard requires lessors to account for leases using an approach that is substantially equivalent to existing guidance for sales-type leases, direct financing leases and operating leases. We are evaluating the adoption of ASU 2016-02, but we expect the standard to minimally impact our consolidated financial statements as we currently have four operating ground lease arrangements with terms greater than one year for which we are the lessee, and we don’t expect the purchase of properties with ground leases to be crucial to our acquisition strategy. We also expect our general and administrative expense to increase as the new standard requires us to expense non-incremental leasing costs that were previously capitalized to leasing commissions. ASU 2016-02 supersedes the previous leases standard, ASC 840 “Leases.” The standard is effective on January 1, 2019, with early adoption permitted. We will adopt using the modified retrospective method, under which the cumulative effect of initially applying the guidance is recognized at the date of initial application. In August 2016, the FASB issued ASU 2016-15, “Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments (a consensus of the Emerging Issues Task Force),” which clarifies how entities should classify certain cash receipts and cash payments on the statement of cash flows with the objective of reducing the existing diversity in practice related to eight specific cash flow issues. The areas addressed in the new guidance relate to debt prepayment costs, settlement of zero-coupon debt instruments, contingent consideration payments made after a business combination, proceeds from the settlement of insurance claims, proceeds from the settlement of corporate-owned and bank-owned life insurance policies, distributions received from equity method investments, beneficial interest in securitization transactions and separately identifiable cash flows and application of the predominance principle. We adopted this guidance for the calendar year beginning January 1, 2018, and the standard requires retrospective adoption. Our adoption of this guidance did not have a material impact on our consolidated financial statements, as we have not historically completed transactions contemplated in this update. In November 2016, the FASB issued ASU 2016-18, “Statement of Cash Flows (Topic 230): Restricted Cash (a consensus of the FASB Emerging Issues Task Force),” which requires the statement of cash flows to explain the change during the period in the total of cash, cash equivalents and amounts described as restricted cash or restricted cash equivalents. Under the new guidance, amounts described as restricted cash and restricted cash equivalents will be included with cash and cash equivalents when reconciling the beginning of period and end of period total amounts shown on the statement of cash flows. We adopted this guidance for the calendar year beginning January 1, 2018, and the standard requires retrospective adoption. Our adoption of this guidance did not have a material impact on our consolidated financial statements. In February 2017, the FASB issued ASU 2017-05 to provide guidance for recognizing gains and losses from the transfer of nonfinancial assets and in-substance non-financial assets in contracts with non-customers, unless other specific guidance applies. The standard requires a company to de-recognize nonfinancial assets once it transfers control of a distinct nonfinancial asset or distinct in substance nonfinancial asset. Additionally, when a company transfers its controlling interest in a nonfinancial asset, but retains a noncontrolling ownership interest, the company is required to measure any non-controlling interest it receives or retains at fair value. The guidance requires companies to recognize a full gain or loss on the transaction. As a result of the new guidance, the guidance specific to real estate sales in ASC 360-20 will be eliminated, and partial sales of real estate assets will now be subject to the same de-recognition model as all other nonfinancial assets. We adopted this guidance for the calendar year beginning January 1, 2018, and the standard requires retrospective adoption. Our adoption of this guidance will not have a material impact on our consolidated financial statements, as we typically complete fee simple sales, with no continuing involvement.

Related-Party Transactions

Related-Party Transactions	6 Months Ended
	Jun. 30, 2018
Related Party Transactions [Abstract]
Related-Party Transactions	Related-Party Transactions Gladstone Management and Gladstone Administration We are externally managed pursuant to contractual arrangements with our Adviser and our Administrator, which collectively employ all of our personnel and pay their salaries, benefits, and general expenses directly. Both our Adviser and Administrator are affiliates of ours, as their parent company is owned and controlled by Mr. David Gladstone, our chairman and chief executive officer. Two of our executive officers, Mr. Gladstone and Mr. Terry Lee Brubaker (our vice chairman and chief operating officer) serve as directors and executive officers of our Adviser and our Administrator. Our president, Mr. Robert Cutlip, is an executive managing director of our Adviser. Mr. Michael LiCalsi, our general counsel and secretary, serves as our Administrator’s president, general counsel and secretary. We have entered into an advisory agreement with our Adviser, as amended from time to time (the “Advisory Agreement”), and an administration agreement with our Administrator (the “Administration Agreement”). The services and fees under the Advisory Agreement and Administration Agreement are described below. As of June 30, 2018 and December 31, 2017 , $ 2.4 million and $2.3 million , respectively, were collectively due to our Adviser and Administrator. Base Management Fee On January 10, 2017, we entered into a Fourth Amended and Restated Investment Advisory Agreement with the Adviser, effective as of October 1, 2016. Our original entrance into the Advisory Agreement and each subsequent amendment thereof (including the fourth amendment completed in January of 2017) was approved unanimously by our Board of Directors. Our Board of Directors also reviews and considers renewing the Advisory Agreement each July. During its July 2018 meeting, our Board of Directors reviewed and renewed the Advisory Agreement for an additional year, through August 31, 2019. Under the Advisory Agreement, the calculation of the annual base management fee equals 1.5% of our adjusted total stockholders’ equity, which is our total stockholders’ equity plus total mezzanine equity (before giving effect to the base management fee and incentive fee), adjusted to exclude the effect of any unrealized gains or losses that do not affect realized net income (including impairment charges) and adjusted for any one-time events and certain non-cash items (the later to occur for a given quarter only upon the approval of our Compensation Committee). The fee is calculated and accrued quarterly as 0.375% per quarter of such adjusted total stockholders’ equity figure. Our Adviser does not charge acquisition or disposition fees when we acquire or dispose of properties, as is common in other externally managed REITs. Our Adviser may earn fee income from our borrowers, tenants or other sources. For the three and six months ended June 30, 2018 , we recorded a base management fee of $1.3 million and $2.6 million , respectively. For the three and six months ended June 30, 2017 , we recorded a base management fee of $1.2 million and $2.4 million , respectively. Incentive Fee Pursuant to the Advisory Agreement, the calculation of the incentive fee rewards the Adviser in circumstances where our quarterly Core FFO (defined at the end of this paragraph), before giving effect to any incentive fee, or pre-incentive fee Core FFO, exceeds 2.0% quarterly, or 8.0% annualized, of adjusted total stockholders’ equity (after giving effect to the base management fee but before giving effect to the incentive fee). We refer to this as the hurdle rate. The Adviser will receive 15.0% of the amount of our pre-incentive fee Core FFO that exceeds the hurdle rate. However, in no event shall the incentive fee for a particular quarter exceed by 15.0% (the cap) the average quarterly incentive fee paid by us for the previous four quarters (excluding quarters for which no incentive fee was paid). Core FFO (as defined in the Advisory Agreement) is GAAP net income (loss) available to common stockholders, excluding the incentive fee, depreciation and amortization, any realized and unrealized gains, losses or other non-cash items recorded in net income (loss) available to common stockholders for the period, and one-time events pursuant to changes in GAAP. For the three and six months ended June 30, 2018 , we recorded an incentive fee of $0.7 million and $1.4 million , respectively. For the three and six months ended June 30, 2017 , we recorded an incentive fee of $0.6 million and $1.1 million , respectively. The Adviser did not waive any portion of the incentive fee for the three and six months ended June 30, 2018 or 2017 , respectively. Capital Gain Fee Under the Advisory Agreement, we will pay to the Adviser a capital gains-based incentive fee that will be calculated and payable in arrears as of the end of each fiscal year (or upon termination of the Advisory Agreement). In determining the capital gain fee, we will calculate aggregate realized capital gains and aggregate realized capital losses for the applicable time period. For this purpose, aggregate realized capital gains and losses, if any, equals the realized gain or loss calculated by the difference between the sales price of the property, less any costs to sell the property and the current gross value of the property (which is calculated as the original acquisition price plus any subsequent non-reimbursed capital improvements). At the end of the fiscal year, if this number is positive, then the capital gain fee payable for such time period shall equal 15.0% of such amount. No capital gain fee was recognized during the three and six months ended June 30, 2018 or 2017 . Termination Fee The Advisory Agreement includes a termination fee whereby, in the event of our termination thereof without cause (with 120 days’ prior written notice and the vote of at least two-thirds of our independent directors), a termination fee would be payable to the Adviser equal to two times the sum of the average annual base management fee and incentive fee earned by the Adviser during the 24-month period prior to such termination. A termination fee is also payable if the Adviser terminates the Advisory Agreement after we have defaulted and applicable cure periods have expired. The Advisory Agreement may also be terminated for cause by us (with 30 days’ prior written notice and the vote of at least two-thirds of our independent directors), with no termination fee payable. Cause is defined in the agreement to include if the Adviser breaches any material provisions thereof, the bankruptcy or insolvency of the Adviser, dissolution of the Adviser and fraud or misappropriation of funds. Administration Agreement Under the terms of the Administration Agreement, we pay separately for our allocable portion of the Administrator’s overhead expenses in performing its obligations to us including, but not limited to, rent and our allocable portion of the salaries and benefits expenses of our Administrator’s employees, including, but not limited to, our chief financial officer, treasurer, chief compliance officer, general counsel and secretary (who also serves as our Administrator’s president, general counsel and secretary), and their respective staffs. Our allocable portion of the Administrator’s expenses are generally derived by multiplying our Administrator’s total expenses by the approximate percentage of time the Administrator’s employees perform services for us in relation to their time spent performing services for all companies serviced by our Administrator under contractual agreements. For the three and six months ended June 30, 2018 , we recorded an administration fee of $0.4 million and $0.7 million , respectively. For the three and six months ended June 30, 2017 , we recorded an administration fee of $0.3 million and $0.7 million , respectively. Gladstone Securities Gladstone Securities, LLC, (“Gladstone Securities”), is a privately held broker dealer registered with the Financial Industry Regulatory Authority and insured by the Securities Investor Protection Corporation. Gladstone Securities is an affiliate of ours, as its parent company is owned and controlled by Mr. David Gladstone, our chairman and chief executive officer. Mr. Gladstone also serves on the board of managers of Gladstone Securities. Mortgage Financing Arrangement Agreement We entered into an agreement with Gladstone Securities, effective June 18, 2013, for it to act as our non-exclusive agent to assist us with arranging mortgage financing for properties we own (the “Financing Arrangement Agreement”). In connection with this engagement, Gladstone Securities will, from time to time, continue to solicit the interest of various commercial real estate lenders or recommend to us third party lenders offering credit products or packages that are responsive to our needs. We pay Gladstone Securities a financing fee in connection with the services it provides to us for securing mortgage financing on any of our properties. The amount of these financing fees, which are payable upon closing of the financing, are based on a percentage of the amount of the mortgage, generally ranging from 0.15% to a maximum of 1.0% of the mortgage obtained. The amount of the financing fees may be reduced or eliminated, as determined by us and Gladstone Securities, after taking into consideration various factors, including, but not limited to, the involvement of any third party brokers and market conditions. We paid financing fees to Gladstone Securities of $0.001 million and $0.02 million during the three and six months ended June 30, 2018 , respectively, which are included in mortgage notes payable, net, in the condensed consolidated balance sheets, or 0.01% and 0.11% , respectively, of the mortgage principal secured. We paid financing fees to Gladstone Securities of $0.06 million during both the three and six months ended June 30, 2017 , which are included in mortgage notes payable, net, in the condensed consolidated balance sheets, or 0.31% of the mortgage principal secured. Our Board of Directors renewed the Financing Arrangement Agreement for an additional year, through August 31, 2019, at its July 2018 meeting.

(Loss) earnings per Share of Co

(Loss) earnings per Share of Common Stock	6 Months Ended
	Jun. 30, 2018
Earnings Per Share [Abstract]
(Loss) earnings per Share of Common Stock	(Loss) earnings per Share of Common Stock The following tables set forth the computation of basic and diluted (loss) earnings per share of common stock for the three and six months ended June 30, 2018 and 2017 . We computed basic (loss) earnings per share for the three and six months ended June 30, 2018 and 2017 using the weighted average number of shares outstanding during the periods. Diluted (loss) earnings per share for the three and six months ended June 30, 2018 and 2017 reflects additional shares of common stock related to our convertible senior common stock (the “Senior Common Stock”), if the effect would be dilutive, that would have been outstanding if dilutive potential shares of common stock had been issued, as well as an adjustment to net income available to common stockholders as applicable to common stockholders that would result from their assumed issuance (dollars in thousands, except per share amounts). For the three months ended June 30, For the six months ended June 30, 2018 2017 2018 2017 Calculation of basic (loss) earnings per share of common stock: Net (loss) income (attributable) available to common stockholders $ (317 ) $ (2,025 ) $ 1,474 $ (287 ) Denominator for basic weighted average shares of common stock 28,437,852 25,276,824 28,429,470 25,121,239 Basic (loss) earnings per share of common stock $ (0.01 ) $ (0.08 ) $ 0.05 $ (0.01 ) Calculation of diluted (loss) earnings per share of common stock: Net (loss) income (attributable) available to common stockholders $ (317 ) $ (2,025 ) $ 1,474 $ (287 ) Add: income impact of assumed conversion of senior common stock (1) — — — — Net (loss) income (attributable) available to common stockholders plus assumed conversions (1) $ (317 ) $ (2,025 ) $ 1,474 $ (287 ) Denominator for basic weighted average shares of common stock 28,437,852 25,276,824 28,429,470 25,121,239 Effect of convertible Senior Common Stock (1) — — — — Denominator for diluted weighted average shares of common stock (1) 28,437,852 25,276,824 28,429,470 25,121,239 Diluted (loss) earnings per share of common stock $ (0.01 ) $ (0.08 ) $ 0.05 $ (0.01 ) (1) We excluded shares of Senior Common Stock that are convertible into shares of our common stock in the amount of 744,327 and 783,236 from the calculation of diluted (loss) earnings per share for the three and six months ended June 30, 2018 and 2017 , respectively, because it was anti-dilutive.

Real Estate and Intangible Asse

Real Estate and Intangible Assets	6 Months Ended
	Jun. 30, 2018
Real Estate [Abstract]
Real Estate and Intangible Assets	Real Estate and Intangible Assets Real Estate The following table sets forth the components of our investments in real estate as of June 30, 2018 and December 31, 2017 , excluding real estate held for sale as of June 30, 2018 and December 31, 2017 (dollars in thousands): June 30, 2018 December 31, 2017 Real estate: Land $ 122,010 $ 121,783 Building and improvements 719,603 708,948 Tenant improvements 63,736 63,122 Accumulated depreciation (163,349 ) (149,417 ) Real estate, net $ 742,000 $ 744,436 Real estate depreciation expense on building and tenant improvements was $ 7.5 million and $14.8 million for the three and six months ended June 30, 2018 , respectively, and $6.4 million and $12.8 million for the three and six months ended June 30, 2017 , respectively. Acquisitions We acquired one property during the six months ended June 30, 2018 , and one property during the six months ended June 30, 2017 . Both acquisitions are summarized below (dollars in thousands): Six Months Ended Square Footage Lease Term Purchase Price Acquisition Expenses Annualized GAAP Rent Debt Issued or Assumed June 30, 2018 (1) 127,444 9.8 Years $ 14,341 $ 91 (3) $ 1,087 $ — June 30, 2017 (2) 60,016 8.5 Years 15,697 247 (3) 1,680 11,179 (4) (1) On March 9, 2018 , we acquired a 127,444 square foot property in Vance, Alabama for $14.3 million . The annualized GAAP rent on the 9.8 year lease is $1.1 million . (2) On June 22, 2017 , we acquired a 60,016 square foot property in Conshohocken, Pennsylvania for $15.7 million . We assumed $11.2 million of mortgage debt. The annualized GAAP rent on the 8.5 year lease is $1.7 million . (3) We accounted for this transaction under ASU 2017-01, “Clarifying the Definition of a Business.” As a result, we treated our acquisitions during the six months ended June 30, 2018 and 2017 as asset acquisitions rather than business combinations. As a result of this treatment, we capitalized $0.1 million and $0.2 million , respectively, of acquisition costs that would otherwise have been expensed under business combination treatment. (4) We assumed an interest rate swap in connection with $11.2 million of assumed debt on our Conshohocken, Pennsylvania acquisition, pursuant to which we will pay our counterparty a fixed interest rate of 1.80% , and receive a variable interest rate of one month LIBOR from our counterparty. Our total interest rate on this debt is fixed at 3.55% . The interest rate swap had a fair value of $0.04 million upon the date of assumption, and subsequently increased in value to $0.7 million at June 30, 2018 . We have elected to treat this interest rate swap as a cash flow hedge, and all changes in fair market value will be recorded to accumulated other comprehensive income on the consolidated balance sheets. We determined the fair value of assets acquired and liabilities assumed related to the properties acquired during the six months ended June 30, 2018 and 2017 as follows (dollars in thousands): Six months ended June 30, 2018 Six months ended June 30, 2017 Acquired assets and liabilities Purchase price Purchase price Land $ 459 $ 1,996 Building 11,609 9,975 Tenant Improvements 615 905 In-place Leases 509 1,690 Leasing Costs 534 464 Customer Relationships 566 1,256 Above Market Leases 49 — Below Market Leases — (1,030 ) Discount on Assumed Debt — 399 Fair Value of Interest Rate Swap Assumed — 42 Total Purchase Price $ 14,341 $ 15,697 Significant Real Estate Activity on Existing Assets During the six months ended June 30, 2018 and 2017 , we executed one and one new lease, respectively, which are summarized below (dollars in thousands): Six Months Ended Aggregate Square Footage Weighted Average Lease Term Aggregate Annualized GAAP Rent Aggregate Tenant Improvement Aggregate Leasing Commissions June 30, 2018 34,441 3.6 years $ 97 $ — $ 14 June 30, 2017 83,662 11.3 years 1,683 1,020 445 Intangible Assets The following table summarizes the carrying value of intangible assets, liabilities and the accumulated amortization for each intangible asset and liability class as of June 30, 2018 and December 31, 2017 , excluding real estate held for sale, as of June 30, 2018 and December 31, 2017 (dollars in thousands): June 30, 2018 December 31, 2017 Lease Intangibles Accumulated Amortization Lease Intangibles Accumulated Amortization In-place leases $ 80,638 $ (36,834 ) $ 80,355 $ (33,201 ) Leasing costs 56,147 (25,458 ) 55,695 (23,016 ) Customer relationships 59,276 (21,791 ) 58,892 (19,798 ) $ 196,061 $ (84,083 ) $ 194,942 $ (76,015 ) Deferred Rent Receivable/(Liability) Accumulated (Amortization)/Accretion Deferred Rent Receivable/(Liability) Accumulated (Amortization)/Accretion Above market leases $ 14,511 $ (8,439 ) $ 14,425 $ (7,962 ) Below market leases and deferred revenue (26,752 ) 11,474 (26,725 ) 10,475 $ (12,241 ) $ 3,035 $ (12,300 ) $ 2,513 Total amortization expense related to in-place leases, leasing costs and customer relationship lease intangible assets was $ 4.3 million and $8.6 million for the three and six months ended June 30, 2018 , respectively, and $3.5 million and $7.0 million for the three and six months ended June 30, 2017 , respectively, and is included in depreciation and amortization expense in the condensed consolidated statements of operations and comprehensive income. Total amortization related to above-market lease values was $ 0.2 million and $0.5 million for the three and six months ended June 30, 2018 , respectively, and $0.1 million and $0.3 million for the three and six months ended June 30, 2017 , respectively, and is included in rental revenue in the condensed consolidated statements of operations and comprehensive income. Total amortization related to below-market lease values was $ 0.5 million and $1.0 million for the three and six months ended June 30, 2018 , respectively, and $0.3 million and $0.7 million for the three and six months ended June 30, 2017 , respectively, and is included in rental revenue in the condensed consolidated statements of operations and comprehensive income. The weighted average amortization periods in years for the intangible assets acquired during the six months ended June 30, 2018 and 2017 were as follows: Intangible Assets & Liabilities 2018 2017 In-place leases 9.8 8.5 Leasing costs 9.8 8.5 Customer relationships 14.8 13.5 Above market leases 9.8 0.0 Below market leases 0.0 8.5 All intangible assets & liabilities 11.1 9.8

Real Estate Dispositions, Held

Real Estate Dispositions, Held for Sale and Impairment Charges	6 Months Ended
	Jun. 30, 2018
Real Estate [Abstract]
Real Estate Dispositions, Held for Sale and Impairment Charges	Real Estate Dispositions, Held for Sale and Impairment Charges Real Estate Dispositions During the six months ended June 30, 2018 , we continued to execute our capital recycling program, whereby we sold non-core properties and redeployed proceeds to fund property acquisitions in our target secondary growth markets, as well as repay outstanding debt. During the six months ended June 30, 2018 , we sold two non-core properties, located in Arlington, Texas and Tewksbury, Massachusetts, which are summarized in the table below (dollars in thousands): Aggregate Square Footage Sold Aggregate Sales Price Aggregate Sales Costs Aggregate Gain on Sale of Real Estate, net 166,200 $ 11,100 $ 327 $ 1,844 Our dispositions during the six months ended June 30, 2018 were not classified as discontinued operations because they did not represent a strategic shift in operations, nor will they have a major effect on our operations and financial results. Accordingly, the operating results of these properties are included within continuing operations for all periods reported. The table below summarizes the components of operating income from the real estate and related assets disposed of during the three and six months ended June 30, 2018 , and 2017 (dollars in thousands): For the three months ended June 30, For the six months ended June 30, 2018 2017 2018 2017 Operating revenue $ — $ 245 $ 93 $ 525 Operating expense 12 174 161 316 Other income, net — — 1,844 (1) — (Expense) income from real estate and related assets sold $ (12 ) $ 71 $ 1,776 $ 209 (1) Includes a $1.8 million gain on sale of real estate, net on two properties. Real Estate Held for Sale At June 30, 2018 , we had one property classified as held for sale, located in South Hadley, Massachusetts. We have identified a prospective buyer for this property, and we are currently negotiating a purchase and sale agreement. At December 31, 2017 , we had two properties classified as held for sale, located in Arlington, Texas and Tewksbury, Massachusetts. Both of these properties were sold during the six months ended June 30, 2018 . The table below summarizes the components of the assets and liabilities held for sale reflected on the accompanying condensed consolidated balance sheets (dollars in thousands): June 30, 2018 December 31, 2017 Assets Held for Sale Real estate, at cost $ 2,287 $ 12,997 Less: accumulated depreciation 857 3,970 Total real estate held for sale, net 1,430 9,027 Lease intangibles, net 6 9 Deferred rent receivable, net — 10 Total Assets Held for Sale $ 1,436 $ 9,046 Liabilities Held for Sale Asset retirement obligation $ 297 $ 114 Total Liabilities Held for Sale $ 297 $ 114 Impairment Charges We evaluated our portfolio for triggering events to determine if any of our held and used assets were impaired during the six months ended June 30, 2018 and did no t identify any held and used assets which were impaired. We classified one property as held for sale at June 30, 2018 . We performed an analysis of the property classified as held for sale, and compared the fair market value of the asset less selling costs against the carrying value of assets available for sale. We did no t record an impairment charge during the three and six months ended June 30, 2018 , as the fair market value was greater than the carrying value. Fair market value for this asset was calculated using Level 3 inputs (defined in Note 6 “Mortgage Notes Payable and Credit Facility”), which were determined using comparable asset sale data from the respective asset location as well as negotiations with a prospective buyer. We continue to evaluate our properties on a quarterly basis for changes that could create the need to record impairment. Future impairment losses may result, and could be significant, should market conditions deteriorate in the markets in which we hold our assets or we are unable to secure leases at terms that are favorable to us, which could impact the estimated cash flow of our properties over the period in which we plan to hold our properties. Additionally, changes in management’s decisions to either own and lease long-term or sell a particular asset will have an impact on this analysis. We recognized $4.0 million of impairment charges on two properties during the six months ended June 30, 2017 . These properties were impaired through our held for sale carrying value analysis, during the three and six months ended June 30, 2017 , and we concluded that the fair market value less selling costs was below the carrying value of the respective properties. We sold both of these properties during the year ended December 31, 2017.

Mortgage Notes Payable and Cred

Mortgage Notes Payable and Credit Facility	6 Months Ended
	Jun. 30, 2018
Debt Disclosure [Abstract]
Mortgage Notes Payable and Credit Facility	Mortgage Notes Payable and Credit Facility Our mortgage notes payable and Credit Facility as of June 30, 2018 and December 31, 2017 are summarized below (dollars in thousands): Encumbered properties at Carrying Value at Stated Interest Rates at Scheduled Maturity Dates at June 30, 2018 June 30, 2018 December 31, 2017 June 30, 2018 June 30, 2018 Mortgage and other secured loans: Fixed rate mortgage loans 48 $ 378,287 $ 383,189 (1) (2) Variable rate mortgage loans 18 61,590 69,302 (3) (2) Premiums and discounts, net - (334 ) (281 ) N/A N/A Deferred financing costs, mortgage loans, net - (4,470 ) (4,830 ) N/A N/A Total mortgage notes payable, net 66 $ 435,073 $ 447,380 (4) Variable rate revolving credit facility 32 (6) $ 33,400 $ 21,400 LIBOR + 1.75% 10/27/2021 Deferred financing costs, revolving credit facility - (592 ) (685 ) N/A N/A Total revolver, net 32 $ 32,808 $ 20,715 Variable rate term loan facility - (6) $ 75,000 $ 75,000 LIBOR + 1.70% 10/27/2022 Deferred financing costs, term loan facility - (420 ) (468 ) N/A N/A Total term loan, net N/A $ 74,580 $ 74,532 Total mortgage notes payable and credit facility 98 $ 542,461 $ 542,627 (5) (1) Interest rates on our fixed rate mortgage notes payable vary from 3.55% to 6.63% . (2) We have 45 mortgage notes payable with maturity dates ranging from 9/30/2018 through 7/1/2045 . (3) Interest rates on our variable rate mortgage notes payable vary from one month LIBOR + 2.25% to one month LIBOR + 2.75% . At June 30, 2018 , one month LIBOR was approximately 2.09% . (4) The weighted average interest rate on the mortgage notes outstanding at June 30, 2018 was approximately 4.63% . (5) The weighted average interest rate on all debt outstanding at June 30, 2018 was approximately 4.46% . (6) The amount we may draw under our senior unsecured revolving credit facility and term loan facility is based on a percentage of the fair value of a combined pool of 32 unencumbered properties as of June 30, 2018 . N/A - Not Applicable Mortgage Notes Payable As of June 30, 2018 , we had 45 mortgage notes payable, collateralized by a total of 66 properties with a net book value of $639.4 million . We have limited recourse liabilities that could result from any one or more of the following circumstances: a borrower voluntarily filing for bankruptcy, improper conveyance of a property, fraud or material misrepresentation, misapplication or misappropriation of rents, security deposits, insurance proceeds or condemnation proceeds, or physical waste or damage to the property resulting from a borrower’s gross negligence or willful misconduct. We have full recourse for $10.2 million of the mortgages notes payable, net or 2.3% of the outstanding balance. We will also indemnify lenders against claims resulting from the presence of hazardous substances or activity involving hazardous substances in violation of environmental laws on a property. During the six months ended June 30, 2018 , we repaid one mortgage collateralized by one property and partially repaid one mortgage collateralized by two properties, releasing one of the collateralized properties, which are summarized below (dollars in thousands): Variable Rate Debt Repaid Interest Rate on Variable Rate Debt Repaid Fixed Rate Debt Repaid Interest Rate on Fixed Rate Debt Repaid $ 6,738 LIBOR + 2.25% $ 9,444 5.75 % During the six months ended June 30, 2018 , we issued one mortgage, collateralized by one property, which is summarized in the table below (dollars in thousands): Debt Issued Interest Rate on Debt $ 9,380 (1) 4.58% (2) (1) We issued $9.4 million of swapped to fixed rate debt in connection with one property with a maturity date of March 1, 2023 . (2) We entered into an interest rate swap and will be paying an all in fixed rate of 4.58% . On April 18, 2018 , we extended the maturity dates on two existing variable rate mortgage notes totaling $13.0 million from July 2018 to July 2020. We made payments of $0.03 million and $0.2 million for deferred financing costs during the three and six months ended June 30, 2018 , respectively, and $0.4 million for deferred financing costs during both the three and six months ended June 30, 2017 . Scheduled principal payments of mortgage notes payable for the six months ending 2018 , and each of the five succeeding fiscal years and thereafter are as follows (dollars in thousands): Year Scheduled Principal Payments Six Months Ending December 31, 2018 $ 20,695 2019 48,038 2020 31,772 2021 33,506 2022 97,333 2023 69,225 Thereafter 139,308 Total $ 439,877 (1) (1) This figure does not include $0.3 million of premiums and discounts, net, and $4.5 million of deferred financing costs, which are reflected in mortgage notes payable, net on the condensed consolidated balance sheets. We believe we will be able to address all mortgage notes payable maturing over the next 12 months through a combination of refinancing our existing indebtedness, cash from operations, proceeds from one or more equity offerings and availability on our Credit Facility. Interest Rate Cap and Interest Rate Swap Agreements We have entered into interest rate cap agreements that cap the interest rate on certain of our variable-rate debt and we have assumed or entered into interest rate swap agreements in which we hedged our exposure to variable interest rates by agreeing to pay fixed interest rates to our respective counterparty. We have adopted the fair value measurement provisions for our financial instruments recorded at fair value. The fair value guidance establishes a three-tier value hierarchy, which prioritizes the inputs used in measuring fair value. These tiers include: Level 1, defined as observable inputs such as quoted prices in active markets; Level 2, defined as inputs other than quoted prices in active markets that are either directly or indirectly observable; and Level 3, defined as unobservable inputs in which little or no market data exists, therefore requiring an entity to develop its own assumptions. Generally, we will estimate the fair value of our interest rate caps and interest rate swaps, in the absence of observable market data, using estimates of value including estimated remaining life, counterparty credit risk, current market yield and interest rate spreads of similar securities as of the measurement date. At June 30, 2018 and December 31, 2017 , our interest rate cap agreements and interest rate swap were valued using Level 2 inputs. The fair value of the interest rate cap agreements is recorded in Other assets on our accompanying condensed consolidated balance sheets. We record changes in the fair value of the interest rate cap agreements quarterly based on the current market valuations at quarter end. If the interest rate cap qualifies for hedge accounting, the change in the estimated fair value is recorded to accumulated other comprehensive income to the extent that it is effective, with any ineffective portion recorded to interest expense in our condensed consolidated statements of operations and comprehensive income. If the interest rate cap does not qualify for hedge accounting, or if it is determined the hedge is ineffective, any change in the fair value is recognized in interest expense in our consolidated statements of operations and comprehensive income. The following table summarizes the interest rate caps at June 30, 2018 and December 31, 2017 (dollars in thousands): June 30, 2018 December 31, 2017 Aggregate Cost Aggregate Notional Amount Aggregate Fair Value Aggregate Notional Amount Aggregate Fair Value $ 1,111 (1) $ 135,671 $ 1,115 $ 143,512 $ 504 (1) We have entered into various interest rate cap agreements on variable rate debt with LIBOR caps ranging from 2.25% to 3.25% . We assumed an interest rate swap agreement in connection with our June 22, 2017 acquisition, whereby we will pay our counterparty an interest rate equivalent to 1.80% on a monthly basis, and receive payments from our counterparty equivalent to one month LIBOR. The fair value of our interest rate swap agreement is recorded in Other assets on our accompanying condensed consolidated balance sheets. We have designated our interest rate swap as a cash flow hedge, and we record changes in the fair value of the interest rate swap agreement to accumulated other comprehensive income on the condensed consolidated balance sheets. We record changes in fair value on a quarterly basis, using current market valuations at quarter end. We assumed our interest rate swap with a value of $0.04 million on the date of assumption, and the fair market value increased to $0.7 million at June 30, 2018 . The swap had an original notional value equal to the debt we assumed of $11.2 million , and has a termination date of April 1, 2026 , which is also the maturity date of the assumed debt. We entered into an interest rate swap agreement in connection with a mortgage obtained on a Columbus, Ohio property, whereby we will pay our counterparty an interest rate equivalent to 2.83% on a monthly basis, and receive payments from our counterparty equivalent to one month LIBOR. The fair value of our interest rate swap agreement is recorded in Other assets on our accompanying condensed consolidated balance sheets. We have designated our interest rate swap as a cash flow hedge, and we record changes in the fair value of the interest rate swap agreement to accumulated other comprehensive income on the condensed consolidated balance sheets. We record changes in fair value on a quarterly basis, using current market valuations at quarter end. The fair market value at June 30, 2018 was a $0.1 million liability. The swap has a notional value equal to the debt we issued of $9.4 million , and has a termination date of March 1, 2023 , which is also the maturity date of the issued debt. The following tables present the impact of our derivative instruments in the condensed consolidated financial statements (dollars in thousands): Amount of Gain recognized in Comprehensive Income Three Months Ended June 30, Six Months Ended June 30, 2018 2017 2018 2017 Derivatives in cash flow hedging relationships Interest rate caps $ 97 $ — $ 470 $ — Interest rate swap 192 179 313 179 Total $ 289 $ 179 $ 783 $ 179 The following table sets forth certain information regarding our derivative instruments (dollars in thousands): Asset Derivatives Fair Value at Derivatives Designated as Hedging Instruments Balance Sheet Location June 30, 2018 December 31, 2017 Interest rate caps Other assets $ 920 $ 450 Derivatives Not Designated as Hedging Instruments Interest rate caps Other assets $ 195 $ 54 Total derivatives $ 1,115 $ 504 The fair value of all mortgage notes payable outstanding as of June 30, 2018 was $435.1 million , as compared to the carrying value stated above of $439.9 million . The fair value is calculated based on a discounted cash flow analysis, using management’s estimate of market interest rates on long-term debt with comparable terms and loan to value ratios. The fair value was calculated using Level 3 inputs of the hierarchy established by ASC 820, “Fair Value Measurements and Disclosures.” Credit Facility On August 7, 2013, we procured our senior unsecured revolving credit facility (“Revolver”) with KeyBank National Association (“KeyBank”) (serving as revolving lender, a letter of credit issuer and an administrative agent). In October 2015, we expanded our Revolver to $85.0 million and entered into a term loan facility (“Term Loan”) whereby we added a $25.0 million , five -year Term Loan subject to the same leverage tiers as the Revolver, with the interest rate at each leverage tier being five basis points lower than that of the Revolver. We have the option to repay the Term Loan in full, or in part, at any time without penalty or premium prior to the maturity date. We refer to the Revolver and Term Loan collectively herein as the Credit Facility. On October 27, 2017, we amended our Credit Facility, increasing the Term Loan from $25.0 million , to $75.0 million , with the Revolver commitment remaining at $85.0 million . The Term Loan has a new five -year term, with a maturity date of October 27, 2022, and the Revolver has a new four -year term, with a maturity date of October 27, 2021. The interest rate for the Credit Facility was reduced by 25 basis points at each of the leverage tiers. We entered into interest rate cap agreements on the amended Term Loan, which cap LIBOR at 2.75% . We used the net proceeds of the amended Credit Facility to repay all previously existing borrowings under the Revolver. We incurred fees of approximately $0.9 million in connection with the Credit Facility amendment. The bank syndicate is now comprised of KeyBank, Fifth Third Bank, US Bank National Association and The Huntington National Bank. As of June 30, 2018 , there was $108.4 million outstanding under our Credit Facility at a weighted average interest rate of approximately 3.81% and $1.0 million outstanding under letters of credit at a weighted average interest rate of 1.75% . As of June 30, 2018 , the maximum additional amount we could draw under the Revolver was $46.1 million . We were in compliance with all covenants under the Credit Facility as of June 30, 2018 . The amount outstanding under the Credit Facility approximates fair value as of June 30, 2018 .

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Ground Leases We are obligated as lessee under four ground leases. Future minimum rental payments due under the terms of these leases as of June 30, 2018 are as follows (dollars in thousands): Year Minimum Rental Payments Due Six Months Ending December 31, 2018 $ 233 2019 465 2020 466 2021 392 2022 319 2023 322 Thereafter 3,914 Total $ 6,111 Rental expense incurred for properties with ground lease obligations during the three and six months ended June 30, 2018 was $0.1 million and $0.2 million , respectively, and during the three and six months ended June 30, 2017 was $0.1 million and $0.2 million , respectively. Rental expenses are reflected in property operating expenses on the condensed consolidated statements of operations and comprehensive income. Letters of Credit As of June 30, 2018 , there was $1.0 million outstanding under letters of credit. These letters of credit are not reflected on our condensed consolidated balance sheets.

Stockholders' and Mezzanine Equ

Stockholders' and Mezzanine Equity	6 Months Ended
	Jun. 30, 2018
Equity [Abstract]
Stockholders' and Mezzanine Equity	Stockholders’ and Mezzanine Equity Stockholders’ Equity The following table summarizes the changes in our stockholders’ equity for the six months ended June 30, 2018 (dollars in thousands): Series A and B Preferred Stock Common Stock Senior Common Stock Series A and B Preferred Stock Senior Common Stock Common Stock Additional Paid in Capital Accumulated Other Comprehensive Income Distributions in Excess of Accumulated Earnings Total Stockholders' Equity Balance at December 31, 2017 2,264,000 28,384,016 904,819 $ 2 $ 1 $ 28 $ 534,790 $ 35 $ (268,058 ) $ 266,798 Issuance of Series A and B preferred stock and common stock, net — 185,084 — — — 1 3,520 — — 3,521 Conversion of senior common stock to common stock — 9,554 (11,435 ) — — — — — — — Retirement of senior common stock, net — — (2,266 ) — — — (34 ) — — (34 ) Distributions declared to common, senior common and preferred stockholders — — — — — — — — (26,982 ) (26,982 ) Comprehensive income — — — — — — — 783 — 783 Net income — — — — — — — — 7,130 7,130 Balance at June 30, 2018 2,264,000 28,578,654 891,118 $ 2 $ 1 $ 29 $ 538,276 $ 818 $ (287,910 ) $ 251,216 Distributions We paid the following distributions per share for the three and six months ended June 30, 2018 and 2017 : For the three months ended June 30, For the six months ended June 30, 2018 2017 2018 2017 Common Stock $ 0.375 $ 0.375 $ 0.750 $ 0.750 Senior Common Stock 0.2625 0.2625 0.5250 0.5250 Series A Preferred Stock 0.4843749 0.4843749 0.9687498 0.9687498 Series B Preferred Stock 0.46875 0.46875 0.9375 0.9375 Series D Preferred Stock 0.4374999 0.4374999 0.8749998 0.8749998 Recent Activity Common Stock ATM Program During the six months ended June 30, 2018 , we sold 0.2 million shares of common stock, raising $3.5 million in net proceeds under our open market sales agreement with Cantor Fitzgerald (the “Common Stock ATM Program”). As of June 30, 2018 , we had remaining capacity to sell up to $82.7 million of common stock under the Common Stock ATM Program. Series A and B Preferred Stock ATM Programs Under another open market sales agreement with Cantor Fitzgerald (the “Series A and B Preferred ATM Program”), we may, from time to time, offer to sell (i) shares of our 7.75% Series A Cumulative Redeemable Preferred Stock (“Series A Preferred”), and (ii) shares of our 7.50% Series B Cumulative Redeemable Preferred Stock (“Series B Preferred”), having an aggregate offering price of up to $40.0 million , through Cantor Fitzgerald, acting as sales agent and/or principal. We did not sell any shares of our Series A Preferred or Series B Preferred during the six months ended June 30, 2018 . As of June 30, 2018 , we had remaining capacity to sell up to $37.2 million of preferred stock under the Series A and B Preferred ATM Program. Mezzanine Equity Our 7.00% Series D Cumulative Redeemable Preferred Stock (“Series D Preferred”), is classified as mezzanine equity in our condensed consolidated balance sheets because it is redeemable at the option of the shareholder upon a change of control of greater than 50% in accordance with ASC 480-10-S99 “Distinguishing Liabilities from Equity,” which requires mezzanine equity classification for preferred stock issuances with redemption features which are outside of the control of the issuer. A change in control of our company, outside of our control, is only possible if a tender offer is accepted by over 90% of our shareholders. All other change in control situations would require input from our Board of Directors. We will periodically evaluate the likelihood that a change of control greater than 50% will take place, and if we deem this probable, we would adjust the Series D Preferred presented in mezzanine equity to their redemption value, with the offset to gain (loss) on extinguishment. We currently believe the likelihood of a change of control greater than 50% is remote. Under a third open market sales agreement with Cantor Fitzgerald (the “Series D Preferred ATM Program”), we may, from time to time, offer to sell shares of our Series D Preferred, having an aggregate offering price of up to $50.0 million , through Cantor Fitzgerald, acting as sales agent and/or principal. During the six months ended June 30, 2018 , we sold approximately 0.1 million shares of our Series D Preferred for net proceeds of $ 2.2 million . As of June 30, 2018 , we had remaining capacity to sell up to $ 18.6 million of Series D Preferred under the Series D Preferred ATM Program. Amendment to Articles of Incorporation On April 11, 2018, we filed with the Maryland State Department of Assessments and Taxation an Articles Supplementary reclassifying 3,500,000 authorized but unissued shares of our convertible senior common stock (the “Senior Common Stock”), as authorized but unissued shares of our common stock. As a result of the reclassification, there were 57,969 authorized but unissued shares of Senior Common Stock. On April 11, 2018, we also filed with the Maryland State Department of Assessments and Taxation an Articles of Amendment to increase the number of shares of capital stock we have authority to issue to 100,000,000 and authorized common stock to 87,700,000 shares.

Subsequent Events

Subsequent Events	6 Months Ended
	Jun. 30, 2018
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events Distributions On July 10, 2018 , our Board of Directors declared the following monthly distributions for the months of July , August and September of 2018 : Record Date Payment Date Common Stock Distributions per Share Series A Preferred Distributions per Share Series B Preferred Distributions per Share Series D Preferred Distributions per Share July 20, 2018 July 31, 2018 $ 0.125 $ 0.1614583 $ 0.15625 $ 0.1458333 August 21, 2018 August 31, 2018 0.125 0.1614583 0.15625 0.1458333 September 19, 2018 September 28, 2018 0.125 0.1614583 0.15625 0.1458333 $ 0.375 $ 0.4843749 $ 0.46875 $ 0.4374999 Senior Common Stock Distributions Payable to the Holders of Record During the Month of: Payment Date Distribution per Share July August 7, 2018 $ 0.0875 August September 10, 2018 0.0875 September October 5, 2018 0.0875 $ 0.2625 ATM Equity Activity Subsequent to June 30, 2018 and through July 30, 2018 , we raised $1.6 million in net proceeds from the sale of 83,430 shares of Common Stock under our Common Stock ATM Program. We made no sales under our Series D Preferred ATM Program or Series A and B Preferred Stock ATM Program subsequent to June 30, 2018 and through July 30, 2018 . Second Amended and Restated Agreement of Limited Partnership On July 11, 2018, the Company, GCLP Business Trust I, and GCLP Business Trust II entered into the Second Amended and Restated Agreement of Limited Partnership of the Operating Partnership. The Second Amended and Restated Partnership Agreement consolidates the previous amendments to the First Amended and Restated Agreement of Limited Partnership of the Operating Partnership and reflects certain updates to applicable law. Financing Activity On July 23, 2018 , we extended the maturity date on one variable rate mortgage note totaling $4.0 million from September 2018 to September 2019.

Organization, Basis of Presen16

Organization, Basis of Presentation and Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Interim Financial Information	Interim Financial Information Our interim financial statements are prepared in accordance with generally accepted accounting principles (“GAAP”) for interim financial information and pursuant to the requirements for reporting on Form 10-Q and in accordance with Article 10 of Regulation S-X. Accordingly, certain disclosures accompanying annual financial statements prepared in accordance with GAAP are omitted. The year-end balance sheet data presented herein was derived from audited financial statements, but does not include all disclosures required by GAAP. In the opinion of our management, all adjustments, consisting solely of normal recurring accruals, necessary for the fair statement of financial statements for the interim period, have been included. The interim financial statements and notes thereto should be read in conjunction with the financial statements and notes thereto included in our Annual Report on Form 10-K for the year ended December 31, 2017 , as filed with the U.S. Securities and Exchange Commission on February 14, 2018 . The results of operations for the three and six months ended June 30, 2018 are not necessarily indicative of the results that may be expected for other interim periods or for the full fiscal year.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting periods. Actual results could materially differ from those estimates.
Critical Accounting Policies	Critical Accounting Policies In preparation of our financial statements in accordance with GAAP, we apply certain critical accounting policies which require management to make judgments that are subjective in nature to make certain estimates and assumptions. Application of our accounting policies involves the exercise of judgment regarding the use of assumptions as to future uncertainties, and as a result, actual results could materially differ from these estimates. A summary of all of our significant accounting policies is provided in Note 1 to our consolidated financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2017 . There were no material changes to our critical accounting policies during the three and six months ended June 30, 2018
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements In May 2014, the Financial Accounting Standards Board (“FASB”) issued guidance regarding the recognition of revenue from contracts with customers. Under this guidance, an entity will recognize revenue to depict the transfer of goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. This guidance also requires improved disclosures regarding the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers. We adopted this guidance for our annual and interim periods beginning January 1, 2018 and will use the modified retrospective method, under which the cumulative effect of initially applying the guidance is recognized at the date of initial application. Our adoption of this guidance did not have a material impact on our consolidated financial statements. Further, as discussed below, once the new guidance regarding the principles for the recognition measurement, presentation and disclosure of leases goes into effect on January 1, 2019, we expect the new revenue standard will apply to executory costs and other components of revenue due under leases that are deemed to be non-lease components (examples include common area maintenance and provision of utilities), even when the revenue for such activities is not separately stipulated in the lease. Revenue from these non-lease components, which were previously recognized on a straight-line basis under current lease guidance, would be recognized under the new revenue guidance as the related services are delivered. As a result, while our total revenue recognized over the lease term would not differ under the new guidance, the revenue recognition pattern could be different. We are currently evaluating the impact of revenue recognition from the adoption of the lease standard on our consolidated financial statements. In February 2016, the FASB issued Accounting Standards Update (“ASU”) 2016-02, “Leases: Amendments to the FASB Accounting Standards Codification” (“ASU 2016-02”). The new standard requires lessees to apply a dual approach, classifying leases as either finance or operating leases based on the principle of whether or not the lease is effectively a financed purchase of the leased asset by the lessee. This classification will determine whether lease expense is recognized based on an effective interest method or on a straight line basis over the term of the lease, respectively. A lessee is also required to record a right-of-use asset and a lease liability for all leases with a term of greater than 12 months regardless of their classification. Leases with a term of 12 months or less will be accounted for similar to existing guidance for operating leases today. The new standard requires lessors to account for leases using an approach that is substantially equivalent to existing guidance for sales-type leases, direct financing leases and operating leases. We are evaluating the adoption of ASU 2016-02, but we expect the standard to minimally impact our consolidated financial statements as we currently have four operating ground lease arrangements with terms greater than one year for which we are the lessee, and we don’t expect the purchase of properties with ground leases to be crucial to our acquisition strategy. We also expect our general and administrative expense to increase as the new standard requires us to expense non-incremental leasing costs that were previously capitalized to leasing commissions. ASU 2016-02 supersedes the previous leases standard, ASC 840 “Leases.” The standard is effective on January 1, 2019, with early adoption permitted. We will adopt using the modified retrospective method, under which the cumulative effect of initially applying the guidance is recognized at the date of initial application. In August 2016, the FASB issued ASU 2016-15, “Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments (a consensus of the Emerging Issues Task Force),” which clarifies how entities should classify certain cash receipts and cash payments on the statement of cash flows with the objective of reducing the existing diversity in practice related to eight specific cash flow issues. The areas addressed in the new guidance relate to debt prepayment costs, settlement of zero-coupon debt instruments, contingent consideration payments made after a business combination, proceeds from the settlement of insurance claims, proceeds from the settlement of corporate-owned and bank-owned life insurance policies, distributions received from equity method investments, beneficial interest in securitization transactions and separately identifiable cash flows and application of the predominance principle. We adopted this guidance for the calendar year beginning January 1, 2018, and the standard requires retrospective adoption. Our adoption of this guidance did not have a material impact on our consolidated financial statements, as we have not historically completed transactions contemplated in this update. In November 2016, the FASB issued ASU 2016-18, “Statement of Cash Flows (Topic 230): Restricted Cash (a consensus of the FASB Emerging Issues Task Force),” which requires the statement of cash flows to explain the change during the period in the total of cash, cash equivalents and amounts described as restricted cash or restricted cash equivalents. Under the new guidance, amounts described as restricted cash and restricted cash equivalents will be included with cash and cash equivalents when reconciling the beginning of period and end of period total amounts shown on the statement of cash flows. We adopted this guidance for the calendar year beginning January 1, 2018, and the standard requires retrospective adoption. Our adoption of this guidance did not have a material impact on our consolidated financial statements. In February 2017, the FASB issued ASU 2017-05 to provide guidance for recognizing gains and losses from the transfer of nonfinancial assets and in-substance non-financial assets in contracts with non-customers, unless other specific guidance applies. The standard requires a company to de-recognize nonfinancial assets once it transfers control of a distinct nonfinancial asset or distinct in substance nonfinancial asset. Additionally, when a company transfers its controlling interest in a nonfinancial asset, but retains a noncontrolling ownership interest, the company is required to measure any non-controlling interest it receives or retains at fair value. The guidance requires companies to recognize a full gain or loss on the transaction. As a result of the new guidance, the guidance specific to real estate sales in ASC 360-20 will be eliminated, and partial sales of real estate assets will now be subject to the same de-recognition model as all other nonfinancial assets. We adopted this guidance for the calendar year beginning January 1, 2018, and the standard requires retrospective adoption. Our adoption of this guidance will not have a material impact on our consolidated financial statements, as we typically complete fee simple sales, with no continuing involvement.
Fair Value Measurements and Disclosures	We have adopted the fair value measurement provisions for our financial instruments recorded at fair value. The fair value guidance establishes a three-tier value hierarchy, which prioritizes the inputs used in measuring fair value. These tiers include: Level 1, defined as observable inputs such as quoted prices in active markets; Level 2, defined as inputs other than quoted prices in active markets that are either directly or indirectly observable; and Level 3, defined as unobservable inputs in which little or no market data exists, therefore requiring an entity to develop its own assumptions. Generally, we will estimate the fair value of our interest rate caps and interest rate swaps, in the absence of observable market data, using estimates of value including estimated remaining life, counterparty credit risk, current market yield and interest rate spreads of similar securities as of the measurement date.

(Loss) earnings per Share of 17

(Loss) earnings per Share of Common Stock (Tables)	6 Months Ended
	Jun. 30, 2018
Earnings Per Share [Abstract]
Basic and Diluted Loss Per Share of Common Stock	The following tables set forth the computation of basic and diluted (loss) earnings per share of common stock for the three and six months ended June 30, 2018 and 2017 . We computed basic (loss) earnings per share for the three and six months ended June 30, 2018 and 2017 using the weighted average number of shares outstanding during the periods. Diluted (loss) earnings per share for the three and six months ended June 30, 2018 and 2017 reflects additional shares of common stock related to our convertible senior common stock (the “Senior Common Stock”), if the effect would be dilutive, that would have been outstanding if dilutive potential shares of common stock had been issued, as well as an adjustment to net income available to common stockholders as applicable to common stockholders that would result from their assumed issuance (dollars in thousands, except per share amounts). For the three months ended June 30, For the six months ended June 30, 2018 2017 2018 2017 Calculation of basic (loss) earnings per share of common stock: Net (loss) income (attributable) available to common stockholders $ (317 ) $ (2,025 ) $ 1,474 $ (287 ) Denominator for basic weighted average shares of common stock 28,437,852 25,276,824 28,429,470 25,121,239 Basic (loss) earnings per share of common stock $ (0.01 ) $ (0.08 ) $ 0.05 $ (0.01 ) Calculation of diluted (loss) earnings per share of common stock: Net (loss) income (attributable) available to common stockholders $ (317 ) $ (2,025 ) $ 1,474 $ (287 ) Add: income impact of assumed conversion of senior common stock (1) — — — — Net (loss) income (attributable) available to common stockholders plus assumed conversions (1) $ (317 ) $ (2,025 ) $ 1,474 $ (287 ) Denominator for basic weighted average shares of common stock 28,437,852 25,276,824 28,429,470 25,121,239 Effect of convertible Senior Common Stock (1) — — — — Denominator for diluted weighted average shares of common stock (1) 28,437,852 25,276,824 28,429,470 25,121,239 Diluted (loss) earnings per share of common stock $ (0.01 ) $ (0.08 ) $ 0.05 $ (0.01 ) (1) We excluded shares of Senior Common Stock that are convertible into shares of our common stock in the amount of 744,327 and 783,236 from the calculation of diluted (loss) earnings per share for the three and six months ended June 30, 2018 and 2017 , respectively, because it was anti-dilutive.

Real Estate and Intangible As18

Real Estate and Intangible Assets (Tables)	6 Months Ended
	Jun. 30, 2018
Real Estate [Abstract]
Components of Investments in Real Estate	The following table sets forth the components of our investments in real estate as of June 30, 2018 and December 31, 2017 , excluding real estate held for sale as of June 30, 2018 and December 31, 2017 (dollars in thousands): June 30, 2018 December 31, 2017 Real estate: Land $ 122,010 $ 121,783 Building and improvements 719,603 708,948 Tenant improvements 63,736 63,122 Accumulated depreciation (163,349 ) (149,417 ) Real estate, net $ 742,000 $ 744,436
Acquisitions	We acquired one property during the six months ended June 30, 2018 , and one property during the six months ended June 30, 2017 . Both acquisitions are summarized below (dollars in thousands): Six Months Ended Square Footage Lease Term Purchase Price Acquisition Expenses Annualized GAAP Rent Debt Issued or Assumed June 30, 2018 (1) 127,444 9.8 Years $ 14,341 $ 91 (3) $ 1,087 $ — June 30, 2017 (2) 60,016 8.5 Years 15,697 247 (3) 1,680 11,179 (4) (1) On March 9, 2018 , we acquired a 127,444 square foot property in Vance, Alabama for $14.3 million . The annualized GAAP rent on the 9.8 year lease is $1.1 million . (2) On June 22, 2017 , we acquired a 60,016 square foot property in Conshohocken, Pennsylvania for $15.7 million . We assumed $11.2 million of mortgage debt. The annualized GAAP rent on the 8.5 year lease is $1.7 million . (3) We accounted for this transaction under ASU 2017-01, “Clarifying the Definition of a Business.” As a result, we treated our acquisitions during the six months ended June 30, 2018 and 2017 as asset acquisitions rather than business combinations. As a result of this treatment, we capitalized $0.1 million and $0.2 million , respectively, of acquisition costs that would otherwise have been expensed under business combination treatment. (4) We assumed an interest rate swap in connection with $11.2 million of assumed debt on our Conshohocken, Pennsylvania acquisition, pursuant to which we will pay our counterparty a fixed interest rate of 1.80% , and receive a variable interest rate of one month LIBOR from our counterparty. Our total interest rate on this debt is fixed at 3.55% . The interest rate swap had a fair value of $0.04 million upon the date of assumption, and subsequently increased in value to $0.7 million at June 30, 2018 . We have elected to treat this interest rate swap as a cash flow hedge, and all changes in fair market value will be recorded to accumulated other comprehensive income on the consolidated balance sheets.
Fair Value of Assets Acquired and Liabilities Assumed	We determined the fair value of assets acquired and liabilities assumed related to the properties acquired during the six months ended June 30, 2018 and 2017 as follows (dollars in thousands): Six months ended June 30, 2018 Six months ended June 30, 2017 Acquired assets and liabilities Purchase price Purchase price Land $ 459 $ 1,996 Building 11,609 9,975 Tenant Improvements 615 905 In-place Leases 509 1,690 Leasing Costs 534 464 Customer Relationships 566 1,256 Above Market Leases 49 — Below Market Leases — (1,030 ) Discount on Assumed Debt — 399 Fair Value of Interest Rate Swap Assumed — 42 Total Purchase Price $ 14,341 $ 15,697
Summary of Lease on Property	During the six months ended June 30, 2018 and 2017 , we executed one and one new lease, respectively, which are summarized below (dollars in thousands): Six Months Ended Aggregate Square Footage Weighted Average Lease Term Aggregate Annualized GAAP Rent Aggregate Tenant Improvement Aggregate Leasing Commissions June 30, 2018 34,441 3.6 years $ 97 $ — $ 14 June 30, 2017 83,662 11.3 years 1,683 1,020 445
Carrying Value of Intangible Assets and Accumulated Amortization	The following table summarizes the carrying value of intangible assets, liabilities and the accumulated amortization for each intangible asset and liability class as of June 30, 2018 and December 31, 2017 , excluding real estate held for sale, as of June 30, 2018 and December 31, 2017 (dollars in thousands): June 30, 2018 December 31, 2017 Lease Intangibles Accumulated Amortization Lease Intangibles Accumulated Amortization In-place leases $ 80,638 $ (36,834 ) $ 80,355 $ (33,201 ) Leasing costs 56,147 (25,458 ) 55,695 (23,016 ) Customer relationships 59,276 (21,791 ) 58,892 (19,798 ) $ 196,061 $ (84,083 ) $ 194,942 $ (76,015 ) Deferred Rent Receivable/(Liability) Accumulated (Amortization)/Accretion Deferred Rent Receivable/(Liability) Accumulated (Amortization)/Accretion Above market leases $ 14,511 $ (8,439 ) $ 14,425 $ (7,962 ) Below market leases and deferred revenue (26,752 ) 11,474 (26,725 ) 10,475 $ (12,241 ) $ 3,035 $ (12,300 ) $ 2,513
Weighted Average Amortization Periods	The weighted average amortization periods in years for the intangible assets acquired during the six months ended June 30, 2018 and 2017 were as follows: Intangible Assets & Liabilities 2018 2017 In-place leases 9.8 8.5 Leasing costs 9.8 8.5 Customer relationships 14.8 13.5 Above market leases 9.8 0.0 Below market leases 0.0 8.5 All intangible assets & liabilities 11.1 9.8

Real Estate Dispositions, Hel19

Real Estate Dispositions, Held for Sale and Impairment Charges (Tables)	6 Months Ended
	Jun. 30, 2018
Real Estate [Abstract]
Summary of Sold Properties	During the six months ended June 30, 2018 , we sold two non-core properties, located in Arlington, Texas and Tewksbury, Massachusetts, which are summarized in the table below (dollars in thousands): Aggregate Square Footage Sold Aggregate Sales Price Aggregate Sales Costs Aggregate Gain on Sale of Real Estate, net 166,200 $ 11,100 $ 327 $ 1,844
Components of Operating Income from Real Estate and Related Assets Disposed	The table below summarizes the components of operating income from the real estate and related assets disposed of during the three and six months ended June 30, 2018 , and 2017 (dollars in thousands): For the three months ended June 30, For the six months ended June 30, 2018 2017 2018 2017 Operating revenue $ — $ 245 $ 93 $ 525 Operating expense 12 174 161 316 Other income, net — — 1,844 (1) — (Expense) income from real estate and related assets sold $ (12 ) $ 71 $ 1,776 $ 209 (1) Includes a $1.8 million gain on sale of real estate, net on two properties.
Components of Assets and Liabilities Held for Sale	The table below summarizes the components of the assets and liabilities held for sale reflected on the accompanying condensed consolidated balance sheets (dollars in thousands): June 30, 2018 December 31, 2017 Assets Held for Sale Real estate, at cost $ 2,287 $ 12,997 Less: accumulated depreciation 857 3,970 Total real estate held for sale, net 1,430 9,027 Lease intangibles, net 6 9 Deferred rent receivable, net — 10 Total Assets Held for Sale $ 1,436 $ 9,046 Liabilities Held for Sale Asset retirement obligation $ 297 $ 114 Total Liabilities Held for Sale $ 297 $ 114

Mortgage Notes Payable and Cr20

Mortgage Notes Payable and Credit Facility (Tables)	6 Months Ended
	Jun. 30, 2018
Debt Disclosure [Abstract]
Company's Mortgage Notes Payable and Line of Credit	Our mortgage notes payable and Credit Facility as of June 30, 2018 and December 31, 2017 are summarized below (dollars in thousands): Encumbered properties at Carrying Value at Stated Interest Rates at Scheduled Maturity Dates at June 30, 2018 June 30, 2018 December 31, 2017 June 30, 2018 June 30, 2018 Mortgage and other secured loans: Fixed rate mortgage loans 48 $ 378,287 $ 383,189 (1) (2) Variable rate mortgage loans 18 61,590 69,302 (3) (2) Premiums and discounts, net - (334 ) (281 ) N/A N/A Deferred financing costs, mortgage loans, net - (4,470 ) (4,830 ) N/A N/A Total mortgage notes payable, net 66 $ 435,073 $ 447,380 (4) Variable rate revolving credit facility 32 (6) $ 33,400 $ 21,400 LIBOR + 1.75% 10/27/2021 Deferred financing costs, revolving credit facility - (592 ) (685 ) N/A N/A Total revolver, net 32 $ 32,808 $ 20,715 Variable rate term loan facility - (6) $ 75,000 $ 75,000 LIBOR + 1.70% 10/27/2022 Deferred financing costs, term loan facility - (420 ) (468 ) N/A N/A Total term loan, net N/A $ 74,580 $ 74,532 Total mortgage notes payable and credit facility 98 $ 542,461 $ 542,627 (5) (1) Interest rates on our fixed rate mortgage notes payable vary from 3.55% to 6.63% . (2) We have 45 mortgage notes payable with maturity dates ranging from 9/30/2018 through 7/1/2045 . (3) Interest rates on our variable rate mortgage notes payable vary from one month LIBOR + 2.25% to one month LIBOR + 2.75% . At June 30, 2018 , one month LIBOR was approximately 2.09% . (4) The weighted average interest rate on the mortgage notes outstanding at June 30, 2018 was approximately 4.63% . (5) The weighted average interest rate on all debt outstanding at June 30, 2018 was approximately 4.46% . (6) The amount we may draw under our senior unsecured revolving credit facility and term loan facility is based on a percentage of the fair value of a combined pool of 32 unencumbered properties as of June 30, 2018 . N/A - Not Applicable
Schedule of Repaid Debt	During the six months ended June 30, 2018 , we repaid one mortgage collateralized by one property and partially repaid one mortgage collateralized by two properties, releasing one of the collateralized properties, which are summarized below (dollars in thousands): Variable Rate Debt Repaid Interest Rate on Variable Rate Debt Repaid Fixed Rate Debt Repaid Interest Rate on Fixed Rate Debt Repaid $ 6,738 LIBOR + 2.25% $ 9,444 5.75 %
Summary of Long-Term Mortgages	During the six months ended June 30, 2018 , we issued one mortgage, collateralized by one property, which is summarized in the table below (dollars in thousands): Debt Issued Interest Rate on Debt $ 9,380 (1) 4.58% (2) (1) We issued $9.4 million of swapped to fixed rate debt in connection with one property with a maturity date of March 1, 2023 . (2) We entered into an interest rate swap and will be paying an all in fixed rate of 4.58% .
Schedule of Principal Payments of Mortgage Notes Payable	Scheduled principal payments of mortgage notes payable for the six months ending 2018 , and each of the five succeeding fiscal years and thereafter are as follows (dollars in thousands): Year Scheduled Principal Payments Six Months Ending December 31, 2018 $ 20,695 2019 48,038 2020 31,772 2021 33,506 2022 97,333 2023 69,225 Thereafter 139,308 Total $ 439,877 (1) (1) This figure does not include $0.3 million of premiums and discounts, net, and $4.5 million of deferred financing costs, which are reflected in mortgage notes payable, net on the condensed consolidated balance sheets.
Summary of Interest Rate Cap Agreement	The following table summarizes the interest rate caps at June 30, 2018 and December 31, 2017 (dollars in thousands): June 30, 2018 December 31, 2017 Aggregate Cost Aggregate Notional Amount Aggregate Fair Value Aggregate Notional Amount Aggregate Fair Value $ 1,111 (1) $ 135,671 $ 1,115 $ 143,512 $ 504 (1) We have entered into various interest rate cap agreements on variable rate debt with LIBOR caps ranging from 2.25% to 3.25% .
Schedule of Derivative Instruments	The following table sets forth certain information regarding our derivative instruments (dollars in thousands): Asset Derivatives Fair Value at Derivatives Designated as Hedging Instruments Balance Sheet Location June 30, 2018 December 31, 2017 Interest rate caps Other assets $ 920 $ 450 Derivatives Not Designated as Hedging Instruments Interest rate caps Other assets $ 195 $ 54 Total derivatives $ 1,115 $ 504 The following tables present the impact of our derivative instruments in the condensed consolidated financial statements (dollars in thousands): Amount of Gain recognized in Comprehensive Income Three Months Ended June 30, Six Months Ended June 30, 2018 2017 2018 2017 Derivatives in cash flow hedging relationships Interest rate caps $ 97 $ — $ 470 $ — Interest rate swap 192 179 313 179 Total $ 289 $ 179 $ 783 $ 179

Commitments and Contingencies (

Commitments and Contingencies (Tables)	6 Months Ended
	Jun. 30, 2018
Commitments and Contingencies Disclosure [Abstract]
Future Minimum Rental Payments Due under Terms of Leases	Future minimum rental payments due under the terms of these leases as of June 30, 2018 are as follows (dollars in thousands): Year Minimum Rental Payments Due Six Months Ending December 31, 2018 $ 233 2019 465 2020 466 2021 392 2022 319 2023 322 Thereafter 3,914 Total $ 6,111

Stockholders' and Mezzanine E22

Stockholders' and Mezzanine Equity (Tables)	6 Months Ended
	Jun. 30, 2018
Equity [Abstract]
Summary of Changes in Stockholders' Equity	The following table summarizes the changes in our stockholders’ equity for the six months ended June 30, 2018 (dollars in thousands): Series A and B Preferred Stock Common Stock Senior Common Stock Series A and B Preferred Stock Senior Common Stock Common Stock Additional Paid in Capital Accumulated Other Comprehensive Income Distributions in Excess of Accumulated Earnings Total Stockholders' Equity Balance at December 31, 2017 2,264,000 28,384,016 904,819 $ 2 $ 1 $ 28 $ 534,790 $ 35 $ (268,058 ) $ 266,798 Issuance of Series A and B preferred stock and common stock, net — 185,084 — — — 1 3,520 — — 3,521 Conversion of senior common stock to common stock — 9,554 (11,435 ) — — — — — — — Retirement of senior common stock, net — — (2,266 ) — — — (34 ) — — (34 ) Distributions declared to common, senior common and preferred stockholders — — — — — — — — (26,982 ) (26,982 ) Comprehensive income — — — — — — — 783 — 783 Net income — — — — — — — — 7,130 7,130 Balance at June 30, 2018 2,264,000 28,578,654 891,118 $ 2 $ 1 $ 29 $ 538,276 $ 818 $ (287,910 ) $ 251,216
Dividends Paid	We paid the following distributions per share for the three and six months ended June 30, 2018 and 2017 : For the three months ended June 30, For the six months ended June 30, 2018 2017 2018 2017 Common Stock $ 0.375 $ 0.375 $ 0.750 $ 0.750 Senior Common Stock 0.2625 0.2625 0.5250 0.5250 Series A Preferred Stock 0.4843749 0.4843749 0.9687498 0.9687498 Series B Preferred Stock 0.46875 0.46875 0.9375 0.9375 Series D Preferred Stock 0.4374999 0.4374999 0.8749998 0.8749998

Subsequent Events (Tables)

Subsequent Events (Tables)	6 Months Ended
	Jun. 30, 2018
Subsequent Events [Abstract]
Monthly Distributions Declared by Company's Board of Directors	On July 10, 2018 , our Board of Directors declared the following monthly distributions for the months of July , August and September of 2018 : Record Date Payment Date Common Stock Distributions per Share Series A Preferred Distributions per Share Series B Preferred Distributions per Share Series D Preferred Distributions per Share July 20, 2018 July 31, 2018 $ 0.125 $ 0.1614583 $ 0.15625 $ 0.1458333 August 21, 2018 August 31, 2018 0.125 0.1614583 0.15625 0.1458333 September 19, 2018 September 28, 2018 0.125 0.1614583 0.15625 0.1458333 $ 0.375 $ 0.4843749 $ 0.46875 $ 0.4374999 Senior Common Stock Distributions Payable to the Holders of Record During the Month of: Payment Date Distribution per Share July August 7, 2018 $ 0.0875 August September 10, 2018 0.0875 September October 5, 2018 0.0875 $ 0.2625

Organization, Basis of Presen24

Organization, Basis of Presentation and Significant Accounting Policies (Detail)	Jun. 30, 2018Agreement
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of operating ground lease arrangements	4

Related-Party Transactions - Ad

Related-Party Transactions - Additional Information (Detail)		Jan. 10, 2017quarter	Jun. 30, 2018USD ($)	Jun. 30, 2017USD ($)	Jun. 30, 2018USD ($)officer	Jun. 30, 2017USD ($)	Dec. 31, 2017USD ($)
Related Party Transaction [Line Items]
Number of executive officers | officer					2
Amount due to Adviser and Administrator	[1]		$ 2,352,000		$ 2,352,000		$ 2,289,000
Annual base management fee, in percentage of stockholders' equity, adjusted to unrealized gains or losses (as percent)		1.50%
Quarterly base management fee, in percentage of stockholders' equity, adjusted to unrealized gains or losses (as percent)		0.375%
Base management fee	[2]		1,260,000	$ 1,207,000	2,556,000	$ 2,387,000
Pre-incentive quarterly fee FFO in percentage of common stockholders' equity that will reward the Adviser (as percent)		2.00%
Pre-incentive annual fee FFO in percentage of common stockholders' equity that will reward the Adviser (as percent)		8.00%
Amount to be paid to Adviser in percentage of pre-incentive fee condition one (as percent)		15.00%
Number of quarters used for the cap of average quarterly incentive fees | quarter		4
Incentive fee	[2]		733,000	551,000	1,429,000	1,120,000
Portion of incentive fee waived			0	0	0	0
Capital gains-based incentive fee (as percent)		15.00%
Capital gain fee			0	0	0	0
Notice period for termination of agreement without cause		120 days
Percentage of independent directors to terminate the Amended Advisory Agreement (as percent)		66.67%
Termination fee payable (as percent)		200.00%
Notice period for termination of agreement with cause		30 days
Administration fee	[2]		360,000	340,000	747,000	700,000
Fees paid			$ 1,000	$ 60,000	$ 20,000	$ 60,000
Financing fee on total secured mortgages percentage (as percent)			0.01%	0.31%	0.11%	31.00%
Minimum
Related Party Transaction [Line Items]
Percentage of the amount of the mortgage (as percent)					0.15%
Maximum
Related Party Transaction [Line Items]
Percentage of the amount of the mortgage (as percent)					1.00%
[1]	Refer to Note 2 “Related-Party Transactions”
[2]	Refer to Note 2 “Related-Party Transactions”

(Loss) earnings per Share of 26

(Loss) earnings per Share of Common Stock - Basic and Diluted Loss Per Share of Common Stock (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Calculation of basic (loss) earnings per share of common stock:
Net (loss) income (attributable) available to common stockholders	$ (317)	$ (2,025)	$ 1,474	$ (287)
Denominator for basic weighted average shares of common stock (in shares)	28,437,852	25,276,824	28,429,470	25,121,239
Basic (loss) earnings per share of common stock (in dollars per share)	$ (0.01)	$ (0.08)	$ 0.05	$ (0.01)
Calculation of diluted (loss) earnings per share of common stock:
Net (loss) income (attributable) available to common stockholders	$ (317)	$ (2,025)	$ 1,474	$ (287)
Add: income impact of assumed conversion of senior common stock	0	0	0	0
Net (loss) income attributable to common stockholders plus assumed conversions	$ (317)	$ (2,025)	$ 1,474	$ (287)
Denominator for basic weighted average shares of common stock (in shares)	28,437,852	25,276,824	28,429,470	25,121,239
Effect of convertible Senior Common Stock (in shares)	0	0	0	0
Denominator for diluted weighted average shares of common stock (in shares)	28,437,852	25,276,824	28,429,470	25,121,239
Diluted (loss) earnings per share of common stock (in dollars per share)	$ (0.01)	$ (0.08)	$ 0.05	$ (0.01)

(Loss) earnings per Share of 27

(Loss) earnings per Share of Common Stock - Basic and Diluted Loss Per Share of Common Stock Additional Information (Detail) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Senior Common Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive convertible shares of senior common stock excluded from calculation of diluted earnings per share	744,327	783,236	744,327,000	783,236,000

Real Estate and Intangible As28

Real Estate and Intangible Assets - Components of Investments in Real Estate (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Real estate:
Land	$ 122,010	$ 121,783
Building and improvements	719,603	708,948
Tenant improvements	63,736	63,122
Accumulated depreciation	(163,349)	(149,417)
Total real estate, net	$ 742,000	$ 744,436

Real Estate and Intangible As29

Real Estate and Intangible Assets - Additional Information (Detail) $ in Thousands	May 26, 2016USD ($)ft²	Jun. 30, 2018USD ($)ft²property	Jun. 30, 2017USD ($)ft²property	Jun. 30, 2018USD ($)ft²property	Jun. 30, 2017USD ($)ft²property	Jun. 22, 2018	Jun. 22, 2017
Real Estate Properties [Line Items]
Number of properties acquired | property		1	1	1	1
Purchase Price				$ 14,341
Change in unrealized gain related to interest rate hedging instruments, net		$ 289	$ 179	$ 783	$ 179
Number of leased properties | property				1	1
Total amortization expense related to lease intangible assets		4,300	3,500	$ 8,600	$ 7,000
Amortization related to below-market lease		500	300	1,000	700
Above market leases
Real Estate Properties [Line Items]
Amortization related to above-market lease		200	100	500	300
Building and Tenant Improvements
Real Estate Properties [Line Items]
Real estate depreciation expense		$ 7,500	$ 6,400	$ 14,800	$ 12,800
Series of Property Acquisitions
Real Estate Properties [Line Items]
Aggregate Square Footage Sold | ft²		127,444	60,016	127,444	60,016
Purchase Price				$ 14,341	$ 15,697
Mortgage loans on real estate, new mortgage loans				$ 0	$ 11,179
Lease Term				9 years 9 months 18 days	8 years 6 months
Annualized GAAP Rent				$ 1,087	$ 1,680
Acquisition Expenses				91	247
Conshohocken, Pennsylvania
Real Estate Properties [Line Items]
Aggregate Square Footage Sold | ft²	60,016
Purchase Price	$ 15,700
Mortgage loans on real estate, new mortgage loans	$ 11,200
Lease Term	8 years 6 months
Annualized GAAP Rent	$ 1,700
Stated interest rate (as percent)						1.80%	1.80%
Asset Acquisitions
Real Estate Properties [Line Items]
Purchase Price					15,697
Interest rate swap
Real Estate Properties [Line Items]
Change in unrealized gain related to interest rate hedging instruments, net		$ 192	$ 179	313	179
Interest rate swap | Asset Acquisitions
Real Estate Properties [Line Items]
Liabilities Assumed				0	$ 42
Change in unrealized gain related to interest rate hedging instruments, net				$ 700
LIBOR | Interest rate swap | Conshohocken, Pennsylvania
Real Estate Properties [Line Items]
Derivative rate (as a percent)							3.55%

Real Estate and Intangible As30

Real Estate and Intangible Assets - Summary of Acquired Properties (Details) $ in Thousands	Mar. 09, 2018USD ($)ft²	Jun. 30, 2018USD ($)ft²	Jun. 30, 2017USD ($)ft²
Business Acquisition [Line Items]
Purchase Price		$ 14,341
Series of Property Acquisitions
Business Acquisition [Line Items]
Square Footage | ft²		127,444	60,016
Lease Term		9 years 9 months 18 days	8 years 6 months
Purchase Price		$ 14,341	$ 15,697
Acquisition Expenses		91	247
Annualized GAAP Rent		$ 1,087	$ 1,680
Vance, Alabama
Business Acquisition [Line Items]
Square Footage | ft²	127,444
Lease Term	9 years 9 months 18 days
Purchase Price	$ 14,300
Annualized GAAP Rent	$ 1,100

Real Estate and Intangible As31

Real Estate and Intangible Assets - Business Combinations and Asset Acquisitions (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Business Acquisition [Line Items]
Total Purchase Price	$ 14,341
Asset Acquisitions
Business Acquisition [Line Items]
Discount on Assumed Debt	0	$ 399
Total Purchase Price		15,697
Asset Acquisitions | Customer relationships
Business Acquisition [Line Items]
Assets Acquired	566	1,256
Asset Acquisitions | Above market leases
Business Acquisition [Line Items]
Assets Acquired	49	0
Asset Acquisitions | Below Market Leases
Business Acquisition [Line Items]
Fair Value of Interest Rate Swap Assumed	0	(1,030)
Asset Acquisitions | Land
Business Acquisition [Line Items]
Assets Acquired	459	1,996
Asset Acquisitions | Building
Business Acquisition [Line Items]
Assets Acquired	11,609	9,975
Asset Acquisitions | Tenant Improvements
Business Acquisition [Line Items]
Assets Acquired	615	905
Asset Acquisitions | In-place Leases
Business Acquisition [Line Items]
Assets Acquired	509	1,690
Asset Acquisitions | Leasing Costs
Business Acquisition [Line Items]
Assets Acquired	$ 534	$ 464

Real Estate and Intangible As32

Real Estate and Intangible Assets - Summary of Lease on Property (Detail) $ in Thousands	6 Months Ended
	Jun. 30, 2018USD ($)ft²	Jun. 30, 2017USD ($)ft²
Real Estate Properties [Line Items]
Aggregate Square Footage | ft²	34,441	83,662
Aggregate Annualized GAAP Rent	$ 97	$ 1,683
Aggregate Tenant Improvement	0	1,020
Aggregate Leasing Commissions	$ 14	$ 445
Weighted average
Real Estate Properties [Line Items]
Lease Term	3 years 7 months 6 days	11 years 3 months

Real Estate and Intangible As33

Real Estate and Intangible Assets - Carrying Value of Intangible Assets and Accumulated Amortization (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Below market leases and deferred revenue, gross	$ (26,752)	$ (26,725)
Below market leases and deferred revenue, accumulated amortization	11,474	10,475
Lease Intangibles
Finite-Lived Intangible Assets [Line Items]
Lease Intangibles	196,061	194,942
Intangibles, accumulated amortization	(84,083)	(76,015)
In-place leases
Finite-Lived Intangible Assets [Line Items]
Lease Intangibles	80,638	80,355
Intangibles, accumulated amortization	(36,834)	(33,201)
Leasing costs
Finite-Lived Intangible Assets [Line Items]
Lease Intangibles	56,147	55,695
Intangibles, accumulated amortization	(25,458)	(23,016)
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Lease Intangibles	59,276	58,892
Intangibles, accumulated amortization	(21,791)	(19,798)
Above market leases and below market leases and deferred revenue
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets (liabilities), gross	(12,241)	(12,300)
Finite-lived intangible assets (liabilities), accumulated amortization	3,035	2,513
Above market leases
Finite-Lived Intangible Assets [Line Items]
Lease Intangibles	14,511	14,425
Intangibles, accumulated amortization	$ (8,439)	$ (7,962)

Real Estate and Intangible As34

Real Estate and Intangible Assets - Weighted Average Amortization Period for Intangible Assets and Liabilities (Details)	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted average amortization period	11 years 1 month 6 days	9 years 9 months 18 days
In-place leases
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted average amortization period	9 years 9 months 18 days	8 years 6 months
Leasing costs
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted average amortization period	9 years 9 months 18 days	8 years 6 months
Customer relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted average amortization period	14 years 9 months 18 days	13 years 6 months
Above market leases
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted average amortization period	9 years 9 months 18 days	0 days
Below Market Leases
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted average amortization period	0 days	8 years 6 months

Real Estate Dispositions, Hel35

Real Estate Dispositions, Held for Sale and Impairment Charges - Additional Information (Detail)	3 Months Ended		6 Months Ended
	Jun. 30, 2018USD ($)property	Jun. 30, 2017USD ($)	Jun. 30, 2018USD ($)property	Jun. 30, 2017USD ($)property	Dec. 31, 2017property
Real Estate Properties [Line Items]
Number of properties sold			2
Number of real estate properties, held for sale	1		1
Number of impaired assets, held and used	0		0
Impairment charge | $	$ 0	$ 253,000	$ 0	$ 3,999,000
Number of impaired assets sold, held for sale					2
Arlington, Texas and Tewksbury, Massachusetts
Real Estate Properties [Line Items]
Number of real estate properties, held for sale					2
Disposed of by sale
Real Estate Properties [Line Items]
Number of properties sold			2
Held for sale
Real Estate Properties [Line Items]
Number of impaired assets				2

Real Estate Dispositions, Hel36

Real Estate Dispositions, Held for Sale and Impairment Charges Real Estate Dispositions, Held for Sale and Impairment Charges - Summary of Property Sold (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2018USD ($)ft²	Jun. 30, 2017USD ($)	Jun. 30, 2018USD ($)ft²	Jun. 30, 2017USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Impairment charge	$ 0	$ 253,000	$ 0	$ 3,999,000
Aggregate Gain on Sale of Real Estate, net	$ 0	$ (1,914,000)	$ 1,844,000	$ 3,992,000
Disposed of by sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Aggregate Square Footage Sold | ft²	166,200		166,200
Aggregate Sales Price			$ 11,100,000
Aggregate Sales Costs			327,000
Aggregate Gain on Sale of Real Estate, net			$ 1,844,000

Real Estate Dispositions, Hel37

Real Estate Dispositions, Held for Sale and Impairment Charges - Components of Income from Real Estate and Related Assets Held for Sale (Detail) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018USD ($)	Jun. 30, 2017USD ($)	Jun. 30, 2018USD ($)property	Jun. 30, 2017USD ($)
Real Estate Properties [Line Items]
Operating expense	$ 17,542	$ 14,357	$ 34,944	$ 32,062
(Loss) gain on sale of real estate, net	0	(1,914)	$ 1,844	3,992
Number of properties sold | property			2
Assets disposed of by sale
Real Estate Properties [Line Items]
Operating revenue	0	245	$ 93	525
Operating expense	12	174	161	316
Other income, net	0	0	1,844	0
(Expense) income from real estate and related assets sold	$ (12)	$ 71	1,776	$ 209
(Loss) gain on sale of real estate, net			$ 1,844
Number of properties sold | property			2

Real Estate Dispositions, Hel38

Real Estate Dispositions, Held for Sale and Impairment Charges - Components of Assets and Liabilities Held for Sale (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
ASSETS HELD FOR SALE
Total Assets Held for Sale	$ 1,436	$ 9,046
Liabilities Held for Sale
Total Liabilities Held for Sale	297	114
Real Estate Held for Sale
ASSETS HELD FOR SALE
Real estate, at cost	2,287	12,997
Less: accumulated depreciation	857	3,970
Total real estate held for sale, net	1,430	9,027
Lease intangibles, net	6	9
Deferred rent receivable, net	0	10
Total Assets Held for Sale	1,436	9,046
Liabilities Held for Sale
Asset retirement obligation	297	114
Total Liabilities Held for Sale	$ 297	$ 114

Mortgage Notes Payable and Cr39

Mortgage Notes Payable and Credit Facility - Company's Mortgage Notes Payable and Line of Credit (Detail)	Oct. 27, 2017	Jun. 30, 2018USD ($)property	Apr. 18, 2018USD ($)	Dec. 31, 2017USD ($)
Debt Instrument [Line Items]
Encumbered properties | property		98
Total		$ 542,461,000		$ 542,627,000
LIBOR
Debt Instrument [Line Items]
Spread on LIBOR (as percent)	2.75%
Revolving credit facility
Debt Instrument [Line Items]
Encumbered properties | property		32
Total		$ 32,808,000		20,715,000
Fixed rate mortgage loans
Debt Instrument [Line Items]
Encumbered properties | property		48
Carrying value		$ 378,287,000		383,189,000
Variable rate mortgage loans
Debt Instrument [Line Items]
Encumbered properties | property		18
Carrying value		$ 61,590,000	$ 13,000,000	69,302,000
Variable rate mortgage loans | LIBOR
Debt Instrument [Line Items]
Spread on LIBOR (as percent)		2.25%
Mortgage notes payable
Debt Instrument [Line Items]
Encumbered properties | property		66
Carrying value		$ 439,877,000
Premiums and discounts (net)		(334,000)		(281,000)
Deferred financing costs, net		(4,470,000)		(4,830,000)
Total		$ 435,073,000		447,380,000
Variable rate revolving credit facility | Revolving credit facility
Debt Instrument [Line Items]
Encumbered properties | property		32
Carrying value		$ 33,400,000		21,400,000
Deferred financing costs, net		$ (592,000)		(685,000)
Scheduled maturity dates		Oct. 27, 2021
Variable rate revolving credit facility | Revolving credit facility | LIBOR
Debt Instrument [Line Items]
Spread on LIBOR (as percent)		1.75%
Variable rate term loan facility
Debt Instrument [Line Items]
Carrying value		$ 75,000,000		75,000,000
Scheduled maturity dates		Oct. 27, 2022
Variable rate term loan facility | LIBOR
Debt Instrument [Line Items]
Spread on LIBOR (as percent)		1.70%
Total term loan, net
Debt Instrument [Line Items]
Deferred financing costs, net		$ (420,000)		(468,000)
Total		$ 74,580,000		$ 74,532,000

Mortgage Notes Payable and Cr40

Mortgage Notes Payable and Credit Facility - Company's Mortgage Notes Payable and Line of Credit Additional Information (Detail)	Oct. 27, 2017	Jun. 30, 2018mortgageproperty
Debt Instrument [Line Items]
Weighted average interest rate on debt outstanding (as percent)		4.63%
Encumbered properties		98
Revolving credit facility
Debt Instrument [Line Items]
Encumbered properties		32
LIBOR
Debt Instrument [Line Items]
Spread on LIBOR (as percent)	2.75%
Variable rate at period end (as percent)		2.09%
Fixed rate mortgage loans
Debt Instrument [Line Items]
Stated interest rate (as percent)		5.75%
Maturity date of mortgage notes payable, start date		Sep. 30, 2018
Maturity date of mortgage notes payable, end date		Jul. 1, 2045
Encumbered properties		48
Fixed rate mortgage loans | Minimum
Debt Instrument [Line Items]
Stated interest rate (as percent)		3.545%
Fixed rate mortgage loans | Maximum
Debt Instrument [Line Items]
Stated interest rate (as percent)		6.63%
Mortgage notes payable
Debt Instrument [Line Items]
Number of mortgage notes payable | mortgage		45
Weighted average interest rate on debt outstanding (as percent)		4.46%
Encumbered properties		66
Variable rate mortgage loans
Debt Instrument [Line Items]
Encumbered properties		18
Variable rate mortgage loans | LIBOR
Debt Instrument [Line Items]
Spread on LIBOR (as percent)		2.25%
Variable rate mortgage loans | Maximum | LIBOR
Debt Instrument [Line Items]
Spread on LIBOR (as percent)		2.75%
Variable rate revolving credit facility | Revolving credit facility
Debt Instrument [Line Items]
Encumbered properties		32
Variable rate revolving credit facility | LIBOR | Revolving credit facility
Debt Instrument [Line Items]
Spread on LIBOR (as percent)		1.75%

Mortgage Notes Payable and Cr41

Mortgage Notes Payable and Credit Facility - Additional Information (Detail)	Dec. 01, 2017USD ($)	Oct. 27, 2017USD ($)	May 26, 2016USD ($)	Oct. 31, 2015USD ($)	Jun. 30, 2018USD ($)mortgageproperty	Jun. 30, 2017USD ($)	Jun. 30, 2018USD ($)mortgageproperty	Jun. 30, 2018USD ($)mortgageproperty	Jun. 30, 2018USD ($)mortgageproperty	Jun. 30, 2018USD ($)mortgageproperty	Jun. 30, 2017USD ($)	Jun. 22, 2018USD ($)	Apr. 18, 2018USD ($)	Dec. 31, 2017USD ($)	Jun. 22, 2017	Oct. 05, 2015USD ($)	Aug. 31, 2013USD ($)
Debt Instrument [Line Items]
Number of properties collateralized in mortgage notes payable | property					98		98	98	98	98
Number of long-term mortgages repaid							1		1
Number of properties repaid to collateralized mortgages notes payable | mortgage							1
Number of properties collateralized | property									2
Payments of deferred financing costs								$ 253,000			$ 414,000
Interest rate swap					$ 1,115,000		$ 1,115,000	1,115,000	$ 1,115,000	$ 1,115,000				$ 504,000
Fair value of mortgage notes payable					435,100,000		435,100,000	435,100,000	435,100,000	435,100,000
Maximum borrowing capacity														75,000,000			$ 25,000,000
Extension fee on initial maturity (as percent)		0.25%
Debt instrument fees incurred		$ 900,000
Line of credit outstanding					$ 32,808,000		$ 32,808,000	$ 32,808,000	$ 32,808,000	$ 32,808,000				20,715,000
Weighted average interest rate on debt outstanding (as percent)					4.63%		4.63%	4.63%	4.63%	4.63%
Term Loan Facility
Debt Instrument [Line Items]
Term of debt		5 years
Extension fee on initial maturity (as percent)				0.05%
Revolving credit facility
Debt Instrument [Line Items]
Term of debt		4 years
Line of credit
Debt Instrument [Line Items]
Maximum borrowing capacity				$ 85,000,000												$ 85,000,000
Line of credit outstanding					$ 108,400,000		$ 108,400,000	$ 108,400,000	$ 108,400,000	$ 108,400,000
Weighted average interest rate (as percent)					3.81%		3.81%	3.81%	3.81%	3.81%
Letters of credit, outstanding					$ 1,000,000		$ 1,000,000	$ 1,000,000	$ 1,000,000	$ 1,000,000
Maximum additional amount that can be drawn under Line of Credit					$ 46,100,000		$ 46,100,000	$ 46,100,000	$ 46,100,000	$ 46,100,000
Line of credit | Term Loan Facility
Debt Instrument [Line Items]
Maximum borrowing capacity				$ 25,000,000
Term of debt				5 years
Letter of credit
Debt Instrument [Line Items]
Weighted average interest rate on debt outstanding (as percent)					1.75%		1.75%	1.75%	1.75%	1.75%
Variable rate mortgage loans
Debt Instrument [Line Items]
Number of properties collateralized in mortgage notes payable | property					18		18	18	18	18
Carrying value					$ 61,590,000		$ 61,590,000	$ 61,590,000	$ 61,590,000	$ 61,590,000			$ 13,000,000	69,302,000
Mortgage notes payable
Debt Instrument [Line Items]
Number of mortgage notes payable | mortgage					45		45	45	45	45
Number of properties collateralized in mortgage notes payable | property					66		66	66	66	66
Net book value of collateralized mortgage properties					$ 639,400,000		$ 639,400,000	$ 639,400,000	$ 639,400,000	$ 639,400,000
Recourse amount of mortgage notes payable					10,200,000		10,200,000	10,200,000	10,200,000	$ 10,200,000
Percentage of debt recourse (as percent)										2.30%
Carrying value					$ 439,877,000		$ 439,877,000	$ 439,877,000	$ 439,877,000	$ 439,877,000
Weighted average interest rate on debt outstanding (as percent)					4.46%		4.46%	4.46%	4.46%	4.46%
Issued and assumed mortgage notes payable
Debt Instrument [Line Items]
Number of mortgage notes payable | mortgage					1		1	1	1	1
Number of properties collateralized in mortgage notes payable | property					1		1	1	1	1
Fixed rate mortgage loans
Debt Instrument [Line Items]
Number of properties collateralized in mortgage notes payable | property					48		48	48	48	48
Payments of deferred financing costs					$ 30,000	$ 400,000		$ 200,000			$ 400,000
Stated interest rate (as percent)					5.75%		5.75%	5.75%	5.75%	5.75%
Carrying value					$ 378,287,000		$ 378,287,000	$ 378,287,000	$ 378,287,000	$ 378,287,000				$ 383,189,000
Conshohocken, Pennsylvania
Debt Instrument [Line Items]
Stated interest rate (as percent)												1.80%			1.80%
Mortgage loans on real estate, new mortgage loans			$ 11,200,000
Columbus, Ohio
Debt Instrument [Line Items]
Stated interest rate (as percent)	2.83%
Interest rate swap | Conshohocken, Pennsylvania
Debt Instrument [Line Items]
Interest rate swap					700,000		700,000	700,000	700,000	700,000		$ 0
Interest rate swap | Columbus, Ohio
Debt Instrument [Line Items]
Interest rate swap					$ (100,000)		$ (100,000)	$ (100,000)	$ (100,000)	$ (100,000)
Debt assumed	$ 9,400,000
LIBOR
Debt Instrument [Line Items]
Spread on LIBOR (as percent)		2.75%
LIBOR | Variable rate mortgage loans
Debt Instrument [Line Items]
Spread on LIBOR (as percent)										2.25%

Mortgage Notes Payable and Cr42

Mortgage Notes Payable and Credit Facility - Mortgages Notes Payable (Detail) $ in Thousands	Oct. 27, 2017	Jun. 30, 2018USD ($)property	Jun. 30, 2017USD ($)property
Debt Instrument [Line Items]
Debt Repaid		$ 21,998	$ 40,573
Number of properties acquired | property		1	1
LIBOR
Debt Instrument [Line Items]
Interest Rate on Variable Rate Debt Repaid	2.75%
Variable rate mortgage loans
Debt Instrument [Line Items]
Debt Repaid		$ 6,738
Variable rate mortgage loans | LIBOR
Debt Instrument [Line Items]
Interest Rate on Variable Rate Debt Repaid		2.25%
Variable rate mortgage loans | LIBOR | Weighted average
Debt Instrument [Line Items]
Interest Rate on Variable Rate Debt Repaid		2.25%
Fixed rate mortgage loans
Debt Instrument [Line Items]
Debt Repaid		$ 9,444
Stated interest rate (as percent)		5.75%
New Fixed Rate Mortgage Notes Payable
Debt Instrument [Line Items]
Stated interest rate (as percent)		4.58%
Debt Issued		$ 9,380
Interest rate swap | New Fixed Rate Mortgage Notes Payable
Debt Instrument [Line Items]
Stated interest rate (as percent)		4.58%

Mortgage Notes Payable and Cr43

Mortgage Notes Payable and Credit Facility - Scheduled Principal Payments of Mortgage Notes Payable (Detail) - Mortgage notes payable - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Six Months Ending December 31, 2018	$ 20,695
2,019	48,038
2,020	31,772
2,021	33,506
2,022	97,333
2,023	69,225
Thereafter	139,308
Total	439,877
Premiums and (discounts), net	(334)	$ (281)
Deferred financing costs, net	$ 4,470	$ 4,830

Mortgage Notes Payable and Cr44

Mortgage Notes Payable and Credit Facility - Interest Rate Cap Agreement (Detail) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Aggregate cost	$ 1,111
Notional amount	135,671	$ 143,512
Fair value	$ 1,115	$ 504
Minimum | LIBOR
Debt Instrument [Line Items]
Interest rate (as percent)	2.25%
Maximum | LIBOR
Debt Instrument [Line Items]
Interest rate (as percent)	3.25%

Mortgage Notes Payable and Cr45

Mortgage Notes Payable and Credit Facility - Schedule of Derivative Instruments Impact (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Change in unrealized gain related to interest rate hedging instruments, net	$ 289	$ 179	$ 783	$ 179
Interest rate caps
Derivative Instruments, Gain (Loss) [Line Items]
Change in unrealized gain related to interest rate hedging instruments, net	97	0	470	0
Interest rate swap
Derivative Instruments, Gain (Loss) [Line Items]
Change in unrealized gain related to interest rate hedging instruments, net	$ 192	$ 179	$ 313	$ 179

Mortgage Notes Payable and Cr46

Mortgage Notes Payable and Credit Facility - Schedule of Derivative Instruments' Information (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Asset	$ 1,115	$ 504
Derivatives Designated as Hedging Instruments
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Asset	920	450
Derivatives Not Designated as Hedging Instruments
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Asset	$ 195	$ 54

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018USD ($)lease	Jun. 30, 2017USD ($)	Jun. 30, 2018USD ($)lease	Jun. 30, 2017USD ($)
Other Commitments [Line Items]
Number of leases | lease	4		4
Expenses incurred for the properties listed	$ 0.1	$ 0.1	$ 0.2	$ 0.2
Line of credit
Other Commitments [Line Items]
Letters of credit, outstanding	$ 1		$ 1

Commitments and Contingencies48

Commitments and Contingencies - Future Minimum Rental Payments Due under Terms of Leases (Detail) - Ground leases $ in Thousands	Jun. 30, 2018USD ($)
Operating Leased Assets [Line Items]
Six Months Ending December 31, 2018	$ 233
2,019	465
2,020	466
2,021	392
2,022	319
2,023	322
Thereafter	3,914
Minimum Rental Payments Due	$ 6,111

Stockholders' and Mezzanine E49

Stockholders' and Mezzanine Equity - Summary of Changes in Stockholders' Equity (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity, beginning balance			$ 266,798
Issuance of Series A and B preferred stock and common stock, net			3,521
Retirement of senior common stock, net			(34)
Distributions declared to common, senior common and preferred stockholders			(26,982)
Comprehensive income			783
Net income	$ 2,525	$ 661	7,130	$ 5,020
Stockholders' equity, ending balance	$ 251,216		$ 251,216
Series A and B Preferred Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity, beginning balance (in shares)			2,264,000
Stockholders' equity, beginning balance			$ 2
Stockholders' equity, ending balance (in shares)	2,264,000		2,264,000
Stockholders' equity, ending balance	$ 2		$ 2
Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity, beginning balance (in shares)			28,384,016
Stockholders' equity, beginning balance			$ 28
Issuance of preferred stock and common stock, net (in shares)			185,084
Issuance of Series A and B preferred stock and common stock, net			$ 1
Conversion of senior common stock to common stock (in shares)			9,554
Stockholders' equity, ending balance (in shares)	28,578,654		28,578,654
Stockholders' equity, ending balance	$ 29		$ 29
Common Stock | Senior Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity, beginning balance (in shares)			904,819
Stockholders' equity, beginning balance			$ 1
Conversion of senior common stock to common stock (in shares)			(11,435)
Retirement of senior common stock, net (in shares)			(2,266)
Stockholders' equity, ending balance (in shares)	891,118		891,118
Stockholders' equity, ending balance	$ 1		$ 1
Additional Paid in Capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity, beginning balance			534,790
Issuance of Series A and B preferred stock and common stock, net			3,520
Retirement of senior common stock, net			(34)
Stockholders' equity, ending balance	538,276		538,276
Accumulated Other Comprehensive Income
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity, beginning balance			35
Comprehensive income			783
Stockholders' equity, ending balance	818		818
Distributions in Excess of Accumulated Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity, beginning balance			(268,058)
Distributions declared to common, senior common and preferred stockholders			(26,982)
Net income			7,130
Stockholders' equity, ending balance	$ (287,910)		$ (287,910)

Stockholders' and Mezzanine E50

Stockholders' and Mezzanine Equity - Dividends Paid (Detail) - $ / shares	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Senior Common Stock
Dividends Payable [Line Items]
Common Stock, dividends paid per share	$ 0.2625	$ 0.2625	$ 0.525	$ 0.525
Series A Preferred Stock
Dividends Payable [Line Items]
Preferred Stock, dividends paid per share	0.4843749	0.4843749	0.9687498	0.9687498
Series B Preferred Stock
Dividends Payable [Line Items]
Preferred Stock, dividends paid per share	0.46875	0.46875	0.9375	0.9375
Series D Preferred Stock
Dividends Payable [Line Items]
Preferred Stock, dividends paid per share	0.4374999	0.4374999	0.8749998	0.8749998
Common Stock
Dividends Payable [Line Items]
Common Stock, dividends paid per share	$ 0.375	$ 0.375	$ 0.75	$ 0.75

Stockholders' and Mezzanine E51

Stockholders' and Mezzanine Equity - Additional Information (Detail) - USD ($)	Apr. 11, 2018	Feb. 29, 2016	Jun. 30, 2018	Dec. 31, 2017
Class of Stock [Line Items]
Shares reclassified to common stock	3,500,000
Senior common stock, authorized but unissued	57,969
Capital stock, shares authorized	100,000,000
Common stock, shares authorized	87,700,000		87,700,000	34,200,000
Series A and B Preferred Stock ATM Programs
Class of Stock [Line Items]
Redeemable preferred stock, shares issued (in shares)			2,264,000	2,264,000
Series D Cumulative Redeemable Preferred Stock
Class of Stock [Line Items]
Redeemable preferred stock, dividend rate percentage (as percent)			7.00%
Temporary equity, contract terms, minimum vote needed to trigger change in control from tender offer (as percent)			90.00%
Cantor Fitzgerald & Co | Common Stock
Class of Stock [Line Items]
Redeemable preferred stock, shares issued (in shares)			200,000
Net proceeds from offering			$ 3,500,000
Maximum remaining capacity to sell preferred stock under open market sale agreement			$ 82,700,000
Cantor Fitzgerald & Co | Preferred Stock | Series A and B Preferred Stock ATM Programs
Class of Stock [Line Items]
Redeemable preferred stock, shares issued (in shares)			0
Maximum remaining capacity to sell preferred stock under open market sale agreement			$ 37,200,000
Cantor Fitzgerald & Co | Preferred Stock | Series A Cumulative Redeemable Preferred Stock
Class of Stock [Line Items]
Redeemable preferred stock, dividend rate percentage (as percent)		7.75%
Cantor Fitzgerald & Co | Preferred Stock | Series B Cumulative Redeemable Preferred Stock
Class of Stock [Line Items]
Maximum aggregate sales price of shares to be issued under open market sale agreement		$ 40,000,000
Redeemable preferred stock, dividend rate percentage (as percent)		7.50%
Cantor Fitzgerald & Co | Preferred Stock | Series D Cumulative Redeemable Preferred Stock
Class of Stock [Line Items]
Maximum aggregate sales price of shares to be issued under open market sale agreement			50,000,000
Maximum remaining capacity to sell preferred stock under open market sale agreement			$ 18,600,000
Cantor Fitzgerald & Co | Series D Preferred Stock ATM Program | Series D Cumulative Redeemable Preferred Stock
Class of Stock [Line Items]
Number of shares issued (in shares)			100,000
Consideration received			$ 2,200,000

Subsequent Events - Monthly Dis

Subsequent Events - Monthly Distributions Declared by Company's Board of Directors (Detail) - $ / shares

Oct. 05, 2018

Sep. 28, 2018

Sep. 19, 2018

Sep. 10, 2018

Aug. 31, 2018

Aug. 21, 2018

Aug. 07, 2018

Jul. 31, 2018

Jul. 20, 2018

Sep. 30, 2018

Aug. 31, 2018

Jul. 30, 2018

Jul. 10, 2018

Subsequent event | Series A Preferred Stock

Dividends Payable [Line Items]

Distribution per share (in dollars per share)

$ 0.4843749

Subsequent event | Series B Preferred Stock

Dividends Payable [Line Items]

Distribution per share (in dollars per share)

0.46875

Subsequent event | Series D Preferred Stock

Dividends Payable [Line Items]

Distribution per share (in dollars per share)

0.4374999

Subsequent event | Senior Common Stock

Dividends Payable [Line Items]

Distribution per share (in dollars per share)

0.2625

Subsequent event | Common Stock

Dividends Payable [Line Items]

Distribution per share (in dollars per share)

$ 0.375

Subsequent event | April 2018

Dividends Payable [Line Items]

Record Date

Jul. 20, 2018

Payment Date

Jul. 31, 2018

Subsequent event | April 2018 | Series A Preferred Stock

Dividends Payable [Line Items]

Distribution per share (in dollars per share)

$ 0.1614583

Subsequent event | April 2018 | Series B Preferred Stock

Dividends Payable [Line Items]

Distribution per share (in dollars per share)

0.15625

Subsequent event | April 2018 | Series D Preferred Stock

Dividends Payable [Line Items]

Distribution per share (in dollars per share)

0.1458333

Subsequent event | April 2018 | Senior Common Stock

Dividends Payable [Line Items]

Payable to the Holders of Record During the Month of:

July

Payment Date

Aug. 7, 2018

Distribution per share (in dollars per share)

$ 0.0875

Subsequent event | April 2018 | Common Stock

Dividends Payable [Line Items]

Distribution per share (in dollars per share)

$ 0.125

Forecast | May 2018

Dividends Payable [Line Items]

Record Date

Aug. 21, 2018

Payment Date

Aug. 31, 2018

Forecast | May 2018 | Series A Preferred Stock

Dividends Payable [Line Items]

Distribution per share (in dollars per share)

$ 0.1614583

$ 0.1614583

Forecast | May 2018 | Series B Preferred Stock

Dividends Payable [Line Items]

Distribution per share (in dollars per share)

0.15625

0.15625

Forecast | May 2018 | Series D Preferred Stock

Dividends Payable [Line Items]

Distribution per share (in dollars per share)

0.1458333

$ 0.1458333

Forecast | May 2018 | Senior Common Stock

Dividends Payable [Line Items]

Payable to the Holders of Record During the Month of:

August

Payment Date

Sep. 10, 2018

Distribution per share (in dollars per share)

$ 0.0875

Forecast | May 2018 | Common Stock

Dividends Payable [Line Items]

Distribution per share (in dollars per share)

$ 0.125

$ 0.125

Forecast | June 2018

Dividends Payable [Line Items]

Record Date

Sep. 19, 2018

Payment Date

Sep. 28, 2018

Forecast | June 2018 | Series A Preferred Stock

Dividends Payable [Line Items]

Distribution per share (in dollars per share)

$ 0.1614583

Forecast | June 2018 | Series B Preferred Stock

Dividends Payable [Line Items]

Distribution per share (in dollars per share)

0.15625

Forecast | June 2018 | Series D Preferred Stock

Dividends Payable [Line Items]

Distribution per share (in dollars per share)

0.1458333

Forecast | June 2018 | Senior Common Stock

Dividends Payable [Line Items]

Payable to the Holders of Record During the Month of:

September

Payment Date

Oct. 5, 2018

Distribution per share (in dollars per share)

$ 0.0875

Forecast | June 2018 | Common Stock

Dividends Payable [Line Items]

Distribution per share (in dollars per share)

$ 0.125

Subsequent Events - Additional

Subsequent Events - Additional Information (Details) - USD ($)	1 Months Ended
	Jul. 30, 2018	Jul. 23, 2018	Jun. 30, 2018	Apr. 18, 2018	Dec. 31, 2017
Series D Preferred Stock | Subsequent event
Subsequent Event [Line Items]
Gross proceeds of the offering	$ 1,600,000
Number of shares issued (in shares)	83,430
Variable rate mortgage loans
Subsequent Event [Line Items]
Carrying value			$ 61,590,000	$ 13,000,000	$ 69,302,000
Variable rate mortgage loans | Subsequent event
Subsequent Event [Line Items]
Carrying value		$ 4,000,000