STAG Industrial (STAG) 10-Q 2 May 17 2017 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2017	Apr. 28, 2017
Document and Entity Information
Entity Registrant Name	STAG Industrial, Inc.
Entity Central Index Key	1,479,094
Document Type	10-Q
Document Period End Date	Mar. 31, 2017
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		88,726,553
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q1

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Rental Property:
Land	$ 281,756	$ 272,162
Buildings and improvements, net of accumulated depreciation of $202,095 and $187,413, respectively	1,607,608	1,550,141
Intangible Assets, Net (Excluding Goodwill)	289,275	294,533
Total rental property, net	2,178,639	2,116,836
Cash and cash equivalents	7,082	12,192
Restricted cash	8,720	9,613
Tenant accounts receivable, net	26,555	25,223
Prepaid expenses and other assets	26,224	20,821
Interest rate swaps	2,378	1,471
Assets held for sale, net	1,607	0
Total assets	2,251,205	2,186,156
Liabilities:
Unsecured credit facility	71,000	28,000
Unsecured term loans, net	446,766	446,608
Unsecured notes, net	398,033	397,966
Mortgage notes, net	151,452	163,565
Accounts payable, accrued expenses and other liabilities	30,639	35,389
Interest rate swaps	1,985	2,438
Tenant prepaid rent and security deposits	17,537	15,195
Dividends and distributions payable	10,149	9,728
Deferred leasing intangibles, net of accumulated amortization of $11,443 and $10,450, respectively	19,674	20,341
Total liabilities	1,147,235	1,119,230
Commitments and contingencies
Equity:
Common stock, par value $0.01 per share, 150,000,000 shares authorized, 83,378,593 and 80,352,304 shares issued and outstanding at March 31, 2017 and December 31, 2016, respectively	833	804
Additional paid-in capital	1,360,951	1,293,706
Common stock dividends in excess of earnings	(442,329)	(410,978)
Accumulated other comprehensive loss	(336)	(1,496)
Total stockholders’ equity	1,064,119	1,027,036
Noncontrolling interest	39,851	39,890
Total equity	1,103,970	1,066,926
Total liabilities and equity	2,251,205	2,186,156
Series B Preferred Stock
Equity:
Preferred stock	70,000	70,000
Series C Preferred Stock
Equity:
Preferred stock	$ 75,000	$ 75,000

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Real Estate Investment Property, Accumulated Depreciation	$ 202,095	$ 187,413
Deferred leasing intangibles assets, accumulated amortization	251,089	237,456
Deferred leasing intangibles liabilities, accumulated amortization	$ 11,443	$ 10,450
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized	15,000,000	15,000,000
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	150,000,000	150,000,000
Common Stock, shares issued	83,378,593	80,352,304
Common stock, shares outstanding	83,378,593	80,352,304
Series B Preferred Stock
Preferred stock, shares issued	2,800,000	2,800,000
Preferred stock, shares outstanding	2,800,000	2,800,000
Preferred stock, liquidation preference (in dollars per share)	$ 25	$ 25
Series C Preferred Stock
Preferred stock, shares issued	3,000,000	3,000,000
Preferred stock, shares outstanding	3,000,000	3,000,000
Preferred stock, liquidation preference (in dollars per share)	$ 25	$ 25

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Revenue
Rental income	$ 59,222	$ 51,349
Tenant recoveries	10,185	9,442
Other income	73	81
Total revenue	69,480	60,872
Expenses
Property	13,276	12,655
General and administrative	8,771	11,019
Property acquisition costs	740	552
Depreciation and amortization	35,953	29,749
Unusual or Infrequent Item, or Both, Net of Insurance Proceeds	330	0
Other expenses	194	260
Total expenses	59,264	54,235
Other income (expense)
Interest income	5	3
Interest expense	(10,477)	(10,847)
Loss on extinguishment of debt	0	(1,134)
Gain on the sales of rental property, net	325	17,673
Total other income (expense)	(10,147)	5,695
Net income (loss) from continuing operations	69	12,332
Net income	69	12,332
Less: income (loss) attributable to noncontrolling interest after preferred stock dividends	(103)	482
Net income attributable to STAG Industrial, Inc.	172	11,850
Less: preferred stock dividends	2,448	2,912
Less: amount allocated to participating securities	83	100
Net income (loss) attributable to common stockholders	$ (2,359)	$ 8,838
Weighted Average Number of Shares Outstanding, Basic	81,807,883	67,889,217
Weighted average common shares outstanding — diluted (in shares)	81,807,883	67,964,559
Income (Loss) from Continuing Operations, Per Basic Share	$ (0.03)	$ 0.13
Net income (loss) per share — basic and diluted
Income (loss) from continuing operations attributable to common stockholders - diluted (in dollars per share)	$ (0.03)	0.13
Income (Loss) from Continuing Operations, Per Basic and Diluted Share		$ 0.13

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 69	$ 12,332
Other comprehensive income (loss):
Income (loss) on interest rate swaps	1,212	(11,823)
Other comprehensive income (loss)	1,212	(11,823)
Comprehensive income	1,281	509
Net (income) loss attributable to noncontrolling interest after preferred stock dividends	103	(482)
Other comprehensive (income) loss attributable to noncontrolling interest	(52)	606
Comprehensive income attributable to STAG Industrial, Inc.	$ 1,332	$ 633

Consolidated Statements of Equi

Consolidated Statements of Equity - USD ($) $ in Thousands	Total	Preferred Stock	Common Stock	Additional Paid-in Capital	Common Stock Dividends in excess of Earnings	Accumulated Other Comprehensive Income (Loss)	Total Stockholders' Equity	Noncontrolling Interest - Unit holders in Operating Partnership	Series C Preferred Stock
Balance at Dec. 31, 2015	$ 857,857	$ 139,000	$ 681	$ 1,017,397	$ (332,271)	$ (2,350)	$ 822,457	$ 35,400
Balance (in shares) at Dec. 31, 2015			68,077,333
Increase (Decrease) in Stockholders' Equity
Proceeds from sale of stock		75,000
Offering costs	(2,590)			(2,590)			(2,590)
Issuance of restricted stock, net	1
Dividends and distributions, net	$ (27,888)	(2,912)			(23,692)		(26,604)	(1,284)
Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures	105,469
Non-cash compensation activity	$ 3,631			840			841	2,790
Rebalancing of noncontrolling interest				1,114			1,114	(1,114)
Other comprehensive income	(11,823)					(11,217)	(11,217)	(606)
Net income	12,332	2,912			8,938		11,850	482
Balance at Mar. 31, 2016	906,519	214,000	$ 682	1,016,761	(347,025)	(13,567)	870,851	35,668
Balance (in shares) at Mar. 31, 2016			68,182,802
Balance at Dec. 31, 2015	857,857	139,000	$ 681	1,017,397	(332,271)	(2,350)	822,457	35,400
Balance (in shares) at Dec. 31, 2015			68,077,333
Balance at Dec. 31, 2016	1,066,926	145,000	$ 804	1,293,706	(410,978)	(1,496)	1,027,036	39,890
Balance (in shares) at Dec. 31, 2016			80,352,304
Increase (Decrease) in Stockholders' Equity
Proceeds from sale of stock	68,543		$ 28	68,515			68,543
Proceeds from sales of common stock (in shares)			2,843,907						3,000,000
Offering costs	(1,068)			(1,068)			(1,068)
Dividends and distributions, net	$ (33,143)	(2,448)			(28,881)		(31,329)	(1,814)
Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures	37,353
Non-cash compensation activity	$ 1,431			454			260	1,171
Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures					(194)
Rebalancing of noncontrolling interest				(2,248)			(2,248)	2,248
Other comprehensive income	1,212					1,160	1,160	52
Net income	69	2,448			(2,276)		172	(103)
Balance at Mar. 31, 2017	$ 1,103,970	$ 145,000	$ 833	1,360,951	$ (442,329)	$ (336)	1,064,119	39,851
Balance (in shares) at Mar. 31, 2017			83,378,593
Increase (Decrease) in Stockholders' Equity
Stock Issued During Period, Value, Conversion of Units			$ 1	$ 1,592			$ 1,593	$ (1,593)
Stock Issued During Period, Shares, Conversion of Units			145,029

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Cash flows from operating activities:
Net income	$ 69	$ 12,332
Adjustment to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	35,953	29,749
Loss on Involuntary Conversion	330	0
Non-cash portion of interest expense	345	379
Intangible amortization in rental income, net	1,296	1,666
Straight-line rent adjustments, net	(967)	(424)
Restricted Stock Award, Forfeitures, Dividends	1	2
Loss on extinguishment of debt	0	1,134
Gain on the sales of rental property, net	(325)	(17,673)
Non-cash compensation expense	2,387	3,605
Change in assets and liabilities:
Tenant accounts receivable, net	157	(461)
Restricted cash	(250)	(46)
Prepaid expenses and other assets	(5,723)	(4,280)
Accounts payable, accrued expenses and other liabilities	(4,457)	519
Tenant prepaid rent and security deposits	2,342	(1,285)
Total adjustments	31,089	12,885
Net cash provided by operating activities	31,158	25,217
Cash flows from investing activities:
Acquisitions of land and buildings and improvements	(84,689)	(21,256)
Additions of land and building and improvements	(6,015)	(3,668)
Proceeds from Sale of Buildings	3,919	31,890
Proceeds from Insurance Settlement, Investing Activities	439	0
Restricted cash	1,143	38
Acquisition deposits, net	(645)	167
Acquisitions of deferred leasing intangibles	(15,098)	(6,571)
Net cash provided by (used in) investing activities	(100,946)	600
Cash flows from financing activities:
Proceeds from sale of series C preferred stock	0	75,000
Proceeds from unsecured credit facility	141,000	54,000
Repayment of unsecured credit facility	(98,000)	(104,000)
Repayment of mortgage notes	(12,167)	(16,128)
Payment of loan fees and costs	(35)	(57)
Payments of Debt Extinguishment Costs	0	(1,130)
Payments of Dividends	32,723	27,597
Proceeds from sales of common stock	68,543	0
Payments Related to Tax Withholding for Share-based Compensation	(969)	0
Offering costs	(971)	(2,447)
Net cash provided by (used in) financing activities	64,678	(22,359)
Increase (decrease) in cash and cash equivalents	(5,110)	3,458
Cash and cash equivalents—beginning of period	12,192	12,011
Cash and cash equivalents—end of period	7,082	15,469
Supplemental disclosure:
Cash paid for interest, net of capitalized interest	10,568	8,721
Supplemental schedule of non-cash investing and financing activities
stag_Additionstobuildingandbuildingimprovements	503	0
Noncash or Part Noncash Acquisition, Fixed Assets Acquired	0	39
Acquisitions of deferred leasing intangibles	0	(16)
Partial Disposal of Building Due to Involuntary Conversion	221	0
Investing Other Receivables Due to Involuntary Conversion	(221)	0
Change in additions of land, building, and improvements included in accounts payable, accrued expenses, and other liabilities	1,385	(1,761)
Additions to building and other capital improvements from non-cash compensation	(7)	(9)
Change in loan fees, costs, and offering costs included in accounts payable, accrued expenses, and other liabilities	(67)	(80)
Dividends and distributions declared but not paid	$ 10,149	$ 8,527

Organization and Description of

Organization and Description of Business	3 Months Ended
	Mar. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Description of Business	Organization and Description of Business STAG Industrial, Inc. (the “Company”) is an industrial real estate operating company focused on the acquisition and operation of single-tenant, industrial properties throughout the United States. The Company was formed as a Maryland corporation and has elected to be treated and intends to continue to qualify as a real estate investment trust (“REIT”) under Sections 856 through 860 of the Internal Revenue Code of 1986, as amended (the “Code”). The Company is structured as an umbrella partnership REIT, commonly called an UPREIT, and owns substantially all of its assets and conducts substantially all of its business through its operating partnership, STAG Industrial Operating Partnership, L.P., a Delaware limited partnership (the “Operating Partnership”). As of March 31, 2017 and December 31, 2016 , the Company owned a 95.8% and 95.7% , respectively, common equity interest in the Operating Partnership. The Company, through its wholly owned subsidiary, is the sole general partner of the Operating Partnership. As used herein, the “Company” refers to STAG Industrial, Inc. and its consolidated subsidiaries and partnerships, including the Operating Partnership, except where context otherwise requires. As of March 31, 2017 , the Company owned 324 buildings in 37 states with approximately 63.2 million rentable square feet, consisting of 254 warehouse/distribution buildings, 53 light manufacturing buildings, 16 flex/office buildings, and one building in redevelopment. The Company’s buildings were approximately 94.8% leased to 279 tenants as of March 31, 2017 .

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2017
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Interim Financial Information The accompanying interim financial statements have been presented in conformity with accounting principles generally accepted in the United States of America (“GAAP”) and with the instructions to Form 10-Q and Regulation S-X for interim financial information. Accordingly, these statements do not include all of the information and notes required by GAAP for complete financial statements. In the opinion of management, the accompanying interim financial statements include all adjustments, consisting of normal recurring items, necessary for their fair statement in conformity with GAAP. Interim results are not necessarily indicative of results for a full year. The year-end consolidated balance sheet data was derived from audited financial statements, but does not include all disclosures required by GAAP. The information included in this Quarterly Report on Form 10-Q should be read in conjunction with the Company’s consolidated financial statements and notes thereto contained in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2016 . Basis of Presentation The Company’s consolidated financial statements include the accounts of the Company, the Operating Partnership and their subsidiaries. Interests in the Operating Partnership not owned by the Company are referred to as “Noncontrolling Common Units.” These Noncontrolling Common Units are held by other limited partners in the form of common units ("Other Common Units") and long term incentive plan units (“LTIP units”) issued pursuant to the STAG Industrial, Inc. 2011 Equity Incentive Plan, as amended (the “2011 Plan”). All significant intercompany balances and transactions have been eliminated in the consolidation of entities. The financial statements of the Company are presented on a consolidated basis for all periods presented. Revision of Previously Reported Consolidated Financial Statements In connection with the preparation of the Company's consolidated financial statements for the year ended December 31, 2016, the Company identified an error in the estimated useful life of a building acquired in the fourth quarter of 2014. As a result of the error, depreciation expense had been overstated and thereby rental property, net and equity were understated. The Company concluded that the amounts were not material to any of its previously issued consolidated financial statements. Accordingly, the Company revised these balances in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2016 . These adjustments do not impact the Company’s cash balances for any of the reporting periods. The effects of this revision to the prior period consolidated financial statements are as follows (in thousands, except for per share data). Effect of Revision as of and for the Three Months Ended March 31, 2016 As Previously Reported Adjustment As Revised Consolidated Balance Sheet, March 31, 2016 Total equity $ 903,510 $ 3,009 $ 906,519 Consolidated Statement of Operations, Three Months Ended March 31, 2016 Depreciation and amortization $ 30,280 $ (531 ) $ 29,749 Total expenses $ 54,766 $ (531 ) $ 54,235 Net income $ 11,801 $ 531 $ 12,332 Net income attributable to STAG Industrial, Inc. $ 11,346 $ 504 $ 11,850 Net income attributable to common stockholders $ 8,334 $ 504 $ 8,838 Net income per share attributable to common stockholders — basic and diluted $ 0.12 $ 0.01 $ 0.13 Consolidated Statement of Comprehensive Income (Loss), Three Months Ended March 31, 2016 Comprehensive income (loss) $ (22 ) $ 531 $ 509 Reclassifications and New Accounting Pronouncements Certain prior year amounts have been reclassified to conform to the current year presentation. In February of 2017, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2017-05, Other Income - Gains and Losses from the Derecognition of Nonfinancial Assets (Subtopic 610-20): Clarifying the Scope of Asset Derecognition Guidance and Accounting for Partial Sales of Nonfinancial Assets , which provides guidance for recognizing gains and losses from the transfer of nonfinancial assets in contracts with non-customers. The new standard was issued as part of the new revenue standard (ASU 2014-09, as discussed below), and defines “in substance nonfinancial asset,” unifies guidance related to partial sales of nonfinancial assets, eliminates rules specifically addressing sales of real estate, removes exceptions to the financial asset derecognition model, and clarifies the accounting for contributions of nonfinancial assets to joint ventures. As a result of the new guidance, the guidance specific to real estate sales in Subtopic 360-20 will be eliminated, and sales and partial sales of real estate assets will now be subject to the same derecognition model as all other nonfinancial assets. This standard is effective at the same time an entity adopts ASU 2014-09, and either the full retrospective approach or the modified retrospective approach may be used. The adoption of ASU 2017-05 is not expected to materially impact the Company’s consolidated financial statements. The Company plans to adopt this standard effective January 1, 2018. In January of 2017, the FASB issued ASU 2017-04, Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment . The new standard removes Step 2 of the goodwill impairment test, which requires a hypothetical purchase price allocation. A goodwill impairment will now be the amount by which a reporting unit’s carrying value exceeds its fair value, not to exceed the carrying amount of goodwill. This standard is effective for annual or any interim goodwill impairment tests in fiscal years beginning after December 15, 2019, with early adoption permitted. The Company elected to early adopt this standard effective January 1, 2017. The adoption of this standard did not have a material effect on the Company's consolidated financial statements. In January of 2017, the FASB issued ASU 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business . The new standard provides a screen to determine when a set of assets and activities is not a business. The screen requires that when substantially all of the fair value of the gross assets acquired or disposed of is concentrated in a single identifiable asset or a group of similar identifiable assets, the set is not a business. This standard is effective for annual periods beginning after December 15, 2017 and interim periods within those periods, with early adoption permitted, and should be applied prospectively on or after the effective date. Upon the adoption of ASU 2017-01, it is expected that the majority of the Company's acquisitions will be accounted for as asset acquisitions, whereas under the current guidance the majority of the Company's acquisitions have been accounted for as business combinations. The most significant difference between the two accounting models that will impact the Company's consolidated financial statements is that in an asset acquisition, property acquisition costs are generally a component of the consideration transferred to acquire a group of assets and are capitalized as a component of the cost of the assets, whereas in a business combination, property acquisition costs are expensed and not included as part of the consideration transferred. The Company plans to adopt this standard effective January 1, 2018. In November of 2016, the FASB issued ASU 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash . The new standard requires that the statement of cash flows explain the changes during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. This standard is effective for fiscal years beginning after December 15, 2017 and interim periods within those years, with early adoption permitted, and should be applied using a retrospective transition method to each period presented. Upon the adoption of ASU 2016-18, the Company will reconcile both cash and cash equivalents and restricted cash in the accompanying Statements of Cash Flows, whereas under the current guidance the Company explains the changes during the period for cash and cash equivalents only. The Company expects that it will adopt the standard effective January 1, 2018. In August of 2016, the FASB issued ASU 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments , which provides clarified guidance on the presentation and classification of certain cash receipts and cash payments in the statement of cash flows. This standard is effective for fiscal years beginning after December 15, 2017, and interim periods within those years, with early adoption permitted. The Company elected to early adopt this standard effective July 1, 2016, and the effects of this standard were applied retrospectively to all prior periods presented. The effect of the change in accounting principle was an increase in net cash provided by operating activities of approximately $1.1 million for the three months ended March 31, 2016 and a corresponding increase in net cash used in financing activities for the three months ended March 31, 2016 related to the payment of loan prepayment fees and costs. In February of 2016, the FASB issued ASU 2016-02, Leases (Topic 842) , which sets out the principles for the recognition, measurement, presentation and disclosure of leases for both parties to a contract (i.e. lessees and lessors). Topic 842 supersedes the previous leases standard, Topic 840, Leases . 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 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. ASU 2016-02 is expected to impact the Company’s consolidated financial statements as the Company has certain operating and land lease arrangements for which it is the lessee, which will result in the recording of a right of use asset and the related lease liability. The standard is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years, with early adoption permitted. The new standard must be adopted using a modified retrospective transition and will require application of the new guidance at the beginning of the earliest comparative period. The Company is currently in the process of evaluating the impact the adoption of ASU 2016-02 will have on the Company’s financial position or results of operations, and expects to adopt the standard effective January 1, 2019. In January of 2016, the FASB issued ASU 2016-01, Recognition and Measurement of Financial Assets and Financial Liabilities (Subtopic 825-10) . The amendments in ASU 2016-01 address certain aspects of recognition, measurement, presentation, and disclosure of financial instruments. The standard primarily affects the accounting for equity investments, financial liabilities under the fair value option, and the presentation and disclosure requirements for financial instruments. ASU 2016-01 is effective for the annual periods beginning after December 31, 2017 and for annual periods and interim periods within those years. Early adoption is permitted for all financial statements of fiscal years and interim periods that have not yet been issued. The adoption of ASU 2016-01 is not expected to materially impact the Company’s consolidated financial statements. The Company expects that it will adopt the standard effective January 1, 2018. In May of 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers (Topic 606) . ASU 2014-09 is a comprehensive new revenue recognition model requiring a company to recognize revenue to depict the transfer of goods or services to a customer at an amount reflecting the consideration it expects to receive in exchange for those goods or services. While lease contracts with customers, which constitute a vast majority of the Company's revenues, are specifically excluded from the model's scope, certain of the Company's revenue streams may be impacted by the new guidance. Once the new guidance setting forth principles for the recognition, measurement, presentation and disclosure of leases (ASU 2016-02, as discussed above) goes into effect, the new revenue standard may apply to executory costs and other components of revenue due under leases that are deemed to be non-lease components (such as common area maintenance and provision of utilities), even when the revenue for such activities is not separately stipulated in the lease. In that case, revenue from these items 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 the total revenue recognized over time would not differ under the new guidance, the recognition pattern would be different. The Company is in the process of evaluating the significance of the difference in the recognition pattern that would result from this change. In adopting ASU 2014-09, companies may use either a full retrospective or a modified retrospective approach. The Company has not decided which method of adoption it will use. Additionally, this guidance requires improved disclosures regarding the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers. ASU 2014-09 is effective for the first interim period within annual reporting periods beginning after December 15, 2017. Early adoption is permitted for the first interim period within annual reporting periods beginning after December 15, 2016. The Company is currently in the process of evaluating the impact the adoption of ASU 2014-09 will have on the Company’s financial position or results of operations, and expects that it will adopt the standard effective January 1, 2018. Tenant Accounts Receivable, net As of March 31, 2017 and December 31, 2016 , the Company had an allowance for doubtful accounts of approximately $0.1 million and $0.2 million , respectively. As of March 31, 2017 and December 31, 2016 , the Company had accrued rental income of approximately $19.9 million and $18.4 million , respectively. As of March 31, 2017 and December 31, 2016 , the Company had an allowance on accrued rental income of $0 and $0 , respectively. As of March 31, 2017 and December 31, 2016 , the Company had approximately $10.9 million and $9.0 million , respectively, of total lease security deposits available in the form of existing letters of credit, which are not reflected on the accompanying Consolidated Balance Sheets. As of March 31, 2017 and December 31, 2016 , the Company had approximately $6.0 million and $5.4 million , respectively, of lease security deposits available in cash, which are included in cash and cash equivalents on the accompanying Consolidated Balance Sheets, and approximately $0.4 million and $0.4 million , respectively, of lease security deposits available in cash, which are included in restricted cash on the accompanying Consolidated Balance Sheets. These funds may be used to settle tenant accounts receivables in the event of a default under the related lease. As of March 31, 2017 and December 31, 2016 , the Company's total liability associated with these lease security deposits was approximately $6.4 million and $5.8 million , respectively, and is included in tenant prepaid rent and security deposits on the accompanying Consolidated Balance Sheets. Related Parties As of March 31, 2017 and December 31, 2016 , the Company had approximately $31,000 and $48,000 , respectively, of amounts due from related parties, which are included in prepaid expenses and other assets on the accompanying Consolidated Balance Sheets. Revenue Recognition Tenant Recoveries The Company estimates that real estate taxes, which are the responsibility of certain tenants under the terms of their leases and are not reflected on the Company's consolidated financial statements, were approximately $3.1 million and $2.6 million for the three months ended March 31, 2017 and March 31, 2016 , respectively. These amounts would have been the maximum real estate tax expense of the Company, excluding any penalties or interest, had the tenants not met their contractual obligations for these periods. Termination Income On March 27, 2017, the tenant at the Buena Vista, VA property exercised its early lease termination option per the terms of the lease agreement. The option provided that the tenant's lease terminate effective March 31, 2018 and required the tenant to pay a termination fee of approximately $0.5 million . The termination fee is being recognized on a straight-line basis from March 27, 2017 through the relinquishment of the space on March 31, 2018. The termination fee income of approximately $39,000 is included in rental income on the accompanying Consolidated Statements of Operations for the three months ended March 31, 2017 . On February 9, 2017, the tenant at the Belvidere, IL property exercised its early lease termination option per the terms of the lease agreement. The option provided that the tenant's lease terminate effective February 9, 2017 and required the tenant to pay a termination fee of $54,000 . The full termination fee was recognized and is included in rental income on the accompanying Consolidated Statements of Operations for the three months ended March 31, 2017 . Approximately $0.2 million of termination fee income related to the Golden, CO property, the tenant at which exercised its termination option on December 21, 2016, is included in rental income on the accompanying Consolidated Statements of Operations for the three months ended March 31, 2017 . Taxes Federal Income Taxes The Company's taxable REIT subsidiaries recognized a net loss of approximately $31,000 and $11,000 for the three months ended March 31, 2017 and March 31, 2016 , respectively, which has been included on the accompanying Consolidated Statements of Operations. State and Local Income, Excise, and Franchise Tax State and local income, excise, and franchise taxes in the amount of $0.2 million and $0.2 million have been recorded in other expenses on the accompanying Consolidated Statements of Operations for the three months ended March 31, 2017 and March 31, 2016 , respectively. Uncertain Tax Positions As of March 31, 2017 and December 31, 2016 , there were no liabilities for uncertain tax positions. Concentrations of Credit Risk Management believes the current credit risk portfolio is reasonably well diversified and does not contain any unusual concentration of credit risk.

Rental Property

Rental Property	3 Months Ended
	Mar. 31, 2017
Real Estate [Abstract]
Rental Property	Rental Property The following table summarizes the components of rental property as of March 31, 2017 and December 31, 2016 . Rental Property (in thousands) March 31, 2017 December 31, 2016 Land $ 281,756 $ 272,162 Buildings, net of accumulated depreciation of $134,236 and $125,971, respectivel y 1,468,933 1,408,406 Tenant improvements, net of accumulated depreciation of $29,748 and $28,388, respectively 24,846 24,974 Building and land improvements, net of accumulated depreciation of $38,111 and $33,054, respectivel y 110,937 107,463 Construction in progress 2,892 9,298 Deferred leasing intangibles, net of accumulated amortization of $251,089 and $237,456, respectively 289,275 294,533 Total rental property, net $ 2,178,639 $ 2,116,836 Acquisitions The following table summarizes the acquisitions of the Company during the three months ended March 31, 2017 . Location of Property Square Feet Buildings Purchase Price Jacksonville, FL 1,025,720 4 $ 34,264 Sparks, NV 174,763 1 8,380 Salisbury, NC 288,000 1 8,250 Franklin Township, NJ 183,000 1 12,800 Milford, CT 200,000 1 12,762 Bedford Heights, OH 173,034 1 7,622 Redford, MI 135,728 1 7,769 Warren, MI 154,377 1 7,940 Three months ended March 31, 2017 2,334,622 11 $ 99,787 The following table summarizes the allocation of the consideration paid at the date of acquisition during the three months ended March 31, 2017 for the acquired assets and liabilities in connection with the acquisitions identified in the table above. Acquired Assets and Liabilities Purchase Price (in thousands) Weighted Average Amortization Period (years) of Intangibles at Acquisition Land $ 10,447 N/A Buildings 66,647 N/A Tenant improvements 1,720 N/A Building and land improvements 5,875 N/A Deferred leasing intangibles - In-place leases 9,342 5.4 Deferred leasing intangibles - Tenant relationships 4,383 8.6 Deferred leasing intangibles - Above market leases 1,842 4.8 Deferred leasing intangibles - Below market leases (469 ) 7.5 Total purchase price $ 99,787 The table below sets forth the results of operations for the three months ended March 31, 2017 , for the properties acquired during the three months ended March 31, 2017 , included in the Company’s Consolidated Statements of Operations from the date of acquisition. Results of Operations (in thousands) Three months ended March 31, 2017 Total revenue $ 1,437 Property acquisition costs $ 593 Net loss $ 669 The following tables set forth pro forma information for the three months ended March 31, 2017 and March 31, 2016 . The below pro forma information does not purport to represent what the actual results of operations of the Company would have been had the acquisitions outlined above occurred on the first day of the applicable reporting period, nor do they purport to predict the results of operations of future periods. The pro forma information has not been adjusted for property sales. Pro Forma (in thousands) (1) Three months ended March 31, 2017 Three months ended March 31, 2016 Total revenue $ 70,523 $ 63,504 Net income (2) $ 1,093 $ 12,216 Net income (loss) attributable to common stockholders $ (1,379 ) $ 8,727 (1) The unaudited pro forma information for the three months ended March 31, 2017 and March 31, 2016 is presented as if the properties acquired during the three months ended March 31, 2017 and March 31, 2016 were completed on January 1, 2016 and January 1, 2015 , respectively. (2) The net income for the three months ended March 31, 2017 excludes approximately $0.6 million of property acquisition costs related to the acquisition of buildings that closed during the three months ended March 31, 2017 , and the net income for the three months ended March 31, 2016 was adjusted to include these acquisition costs. Net income for the three months ended March 31, 2016 excludes approximately $0.5 million of property acquisition costs related to the acquisition of buildings that closed during the three months ended March 31, 2016 . Dispositions During the three months ended March 31, 2017 , the Company sold one building comprised of approximately 0.1 million square feet with a net book value of approximately $3.6 million to a third party. This building contributed approximately $15,000 to revenue (exclusive of acceleration of straight line rent) and approximately $8,000 to net loss (exclusive of acceleration of straight line rent and gain on the sales of rental property, net) for the three months ended March 31, 2017 . Net proceeds from the sale of rental property were approximately $3.9 million and the Company recognized a gain on the sales of rental property, net of approximately $0.3 million for the three months ended March 31, 2017 . This disposition was accounted for under the full accrual method. Assets Held for Sale As of March 31, 2017 , the related land, building and improvements, net, and deferred leasing intangibles, net, for two buildings located in Sparks, MD were classified as assets held for sale, net on the accompanying Consolidated Balance Sheets. Involuntary Conversion During the three months ended March 31, 2017, the Company wrote down a building in the amount of approximately $0.6 million related to the involuntary conversion event that occurred on September 1, 2016. The cumulative write down of the building since the involuntary conversion event is approximately $1.3 million as of March 31, 2017. The Company recognized a loss on involuntary conversion of approximately $0.3 million during the three months ended March 31, 2017 . As of March 31, 2017 , the remaining proceeds receivable from the insurance company are estimated to be approximately $0.8 million , which are included in prepaid expenses and other assets on the accompanying Consolidated Balance Sheets. Deferred Leasing Intangibles The following table summarizes the deferred leasing intangibles on the accompanying Consolidated Balance Sheets as of March 31, 2017 and December 31, 2016 . March 31, 2017 December 31, 2016 Deferred Leasing Intangibles (in thousands) Gross Accumulated Amortization Net Gross Accumulated Amortization Net Above market leases $ 71,805 $ (34,594 ) $ 37,211 $ 70,668 $ (32,868 ) $ 37,800 Other intangible lease assets 468,559 (216,495 ) 252,064 461,321 (204,588 ) 256,733 Total deferred leasing intangible assets $ 540,364 $ (251,089 ) $ 289,275 $ 531,989 $ (237,456 ) $ 294,533 Below market leases $ 31,117 $ (11,443 ) $ 19,674 $ 30,791 $ (10,450 ) $ 20,341 Total deferred leasing intangible liabilities $ 31,117 $ (11,443 ) $ 19,674 $ 30,791 $ (10,450 ) $ 20,341 The following table sets forth the amortization expense and the net decrease to rental income for the amortization of deferred leasing intangibles during the three months ended March 31, 2017 and March 31, 2016 . Three months ended March 31, Deferred Leasing Intangibles Amortization (in thousands) 2017 2016 Net decrease to rental income related to above and below market lease amortization $ 1,296 $ 1,666 Amortization expense related to other intangible lease assets $ 18,393 $ 15,913 The following table sets forth the amortization of deferred leasing intangibles over the next five years as of March 31, 2017 . Year Amortization Expense Related to Other Intangible Lease Assets (in thousands) Net Decrease to Rental Income Related to Above and Below Market Lease Amortization (in thousands) Remainder of 2017 $ 48,836 $ 3,703 2018 $ 52,556 $ 3,748 2019 $ 40,064 $ 3,011 2020 $ 31,464 $ 2,587 2021 $ 22,206 $ 1,404

Debt

Debt	3 Months Ended
	Mar. 31, 2017
Debt Disclosure [Abstract]
Debt	Debt The following table sets forth a summary of the Company’s outstanding indebtedness, including borrowings under the Company’s unsecured credit facility, unsecured term loans, unsecured notes, and mortgage notes as of March 31, 2017 and December 31, 2016 . Loan Principal Outstanding as of March 31, 2017 (in thousands) Principal Outstanding as of December 31, 2016 (in thousands) Interest (1) Current Maturity Prepayment Terms (2) Unsecured credit facility: Unsecured Credit Facility (3) $ 71,000 $ 28,000 L + 1.15% Dec-18-2019 i Total unsecured credit facility 71,000 28,000 Unsecured term loans: Unsecured Term Loan C 150,000 150,000 L + 1.30% Sep-29-2020 i Unsecured Term Loan B 150,000 150,000 L + 1.30% Mar-21-2021 i Unsecured Term Loan A 150,000 150,000 L + 1.30% Mar-31-2022 i Total unsecured term loans 450,000 450,000 Less: Total unamortized deferred financing fees and debt issuance costs (3,234 ) (3,392 ) Total carrying value unsecured term loans 446,766 446,608 Unsecured notes: Series F Unsecured Notes 100,000 100,000 3.98 % Jan-05-2023 ii Series A Unsecured Notes 50,000 50,000 4.98 % Oct-1-2024 ii Series D Unsecured Notes 100,000 100,000 4.32 % Feb-20-2025 ii Series B Unsecured Notes 50,000 50,000 4.98 % Jul-1-2026 ii Series C Unsecured Notes 80,000 80,000 4.42 % Dec-30-2026 ii Series E Unsecured Notes 20,000 20,000 4.42 % Feb-20-2027 ii Total unsecured notes 400,000 400,000 Less: Total unamortized deferred financing fees and debt issuance costs (1,967 ) (2,034 ) Total carrying value unsecured notes 398,033 397,966 Mortgage notes payable (secured debt): Union Fidelity Life Insurance Company — 5,384 5.81 % Apr-30-2017 iii Webster Bank, National Association — 2,853 3.66 % May-29-2017 iv Webster Bank, National Association — 3,073 3.64 % May-31-2017 iv Wells Fargo, National Association 4,024 4,043 5.90 % Aug-1-2017 v Connecticut General Life Insurance Company -1 Facility 35,167 35,320 6.50 % Feb-1-2018 vi Connecticut General Life Insurance Company -2 Facility 36,717 36,892 5.75 % Feb-1-2018 vi Connecticut General Life Insurance Company -3 Facility 16,073 16,141 5.88 % Feb-1-2018 vi Wells Fargo Bank, National Association CMBS Loan 56,192 56,608 4.31 % Dec-1-2022 vii Thrivent Financial for Lutherans 3,986 4,012 4.78 % Dec-15-2023 iv Total mortgage notes 152,159 164,326 Total unamortized fair market value premiums 80 112 Less: Total unamortized deferred financing fees and debt issuance costs (787 ) (873 ) Total carrying value mortgage notes 151,452 163,565 Total / weighted average interest rate (4) $ 1,067,251 $ 1,036,139 3.68 % (1) Current interest rate as of March 31, 2017 . At March 31, 2017 , the one-month LIBOR (“L”) was 0.98278% . The current interest rate is not adjusted to include the amortization of deferred financing fees or debt issuance costs incurred in obtaining debt or any unamortized fair market value premiums. The spread over the applicable rate for the Company's unsecured credit facility and unsecured term loans is based on the Company's consolidated leverage ratio, as defined in the respective loan agreements. (2) Prepayment terms consist of (i) pre-payable with no penalty; (ii) pre-payable with penalty; (iii) pre-payable without penalty two months prior to the maturity date; (iv) pre-payable without penalty three months prior to the maturity date; (v) pre-payable without penalty three months prior to the maturity date, however can be defeased; (vi) pre-payable without penalty six months prior to the maturity date; and (vii) pre-payable without penalty three months prior to the maturity date, however can be defeased beginning January 1, 2016. (3) The capacity of the unsecured credit facility is currently $450.0 million . Deferred financing fees and debt issuance costs, net of accumulated amortization related to the unsecured credit facility of approximately $2.1 million and $2.3 million is included in prepaid expenses and other assets on the accompanying Consolidated Balance Sheets as of March 31, 2017 and December 31, 2016 , respectively. (4) The weighted average interest rate was calculated using the fixed interest rate swapped on the current notional amount of $450.0 million of debt, and is not adjusted to include the amortization of deferred financing fees or debt issuance costs incurred in obtaining debt or any unamortized fair market value premiums. The aggregate undrawn nominal commitment on the unsecured credit facility as of March 31, 2017 was approximately $375.6 million , including issued letters of credit. The Company's actual borrowing capacity at any given point in time may be less and is restricted to a maximum amount based on the Company's debt covenant compliance. Total accrued interest for the Company's indebtedness was approximately $5.3 million and $5.7 million as of March 31, 2017 and December 31, 2016 , respectively, and is included in accounts payable, accrued expenses and other liabilities on the accompanying Consolidated Balance Sheets. The table below sets forth the costs included in interest expense related to the Company's debt arrangements on the accompanying Consolidated Statement of Operations for the three months ended March 31, 2017 and March 31, 2016 . Three months ended March 31, Costs Included in Interest Expense (in thousands) 2017 2016 Amortization of deferred financing fees and debt issuance costs $ 526 $ 474 Facility fees - unsecured credit facility $ 238 $ 240 On March 3, 2017, the mortgage note held with Webster Bank, National Association, in which the property located in East Windsor, CT served as collateral for the mortgage note, was paid in full. On March 1, 2017, the mortgage note held with Webster Bank, National Association, in which the property located in Portland, ME served as collateral for the mortgage note, was paid in full. On March 1, 2017, the mortgage note held with Union Fidelity Life Insurance Company, in which the property located in Hazelwood, MO served as collateral for the mortgage note, was paid in full. Financial Covenant Considerations The Company was in compliance with all financial and other covenants as of March 31, 2017 and December 31, 2016 related to its unsecured credit facility, unsecured term loans, unsecured notes, and mortgage notes. The real estate net book value of the properties that are collateral for the Company’s debt arrangements was approximately $211.0 million and $229.9 million at March 31, 2017 and December 31, 2016 , respectively, and is limited to senior, property-level secured debt financing arrangements. Fair Value of Debt The fair value of the Company’s debt was determined by discounting the future cash flows using the current rates at which loans would be made to borrowers with similar credit ratings for loans with similar remaining maturities, similar terms, and similar loan-to-value ratios. The discount rates ranged from approximately 2.13% to 4.54% and 1.92% to 4.85% at March 31, 2017 and December 31, 2016 , respectively, and were applied to each individual debt instrument. The applicable 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. The fair value of the Company’s debt is based on Level 3 inputs. The following table presents the aggregate principal outstanding of the Company’s debt and the corresponding estimate of fair value as of March 31, 2017 and December 31, 2016 (in thousands). March 31, 2017 December 31, 2016 Principal Outstanding Fair Value Principal Outstanding Fair Value Unsecured credit facility $ 71,000 $ 71,000 $ 28,000 $ 28,000 Unsecured term loans 450,000 450,000 450,000 450,000 Unsecured notes 400,000 413,928 400,000 399,091 Mortgage notes 152,159 154,133 164,326 166,099 Total principal amount 1,073,159 $ 1,089,061 1,042,326 $ 1,043,190 Add: Total unamortized fair market value premiums 80 112 Less: Total unamortized deferred financing fees and debt issuance costs (5,988 ) (6,299 ) Total carrying value $ 1,067,251 $ 1,036,139

Use of Derivative Financial Ins

Use of Derivative Financial Instruments	3 Months Ended
	Mar. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Use of Derivative Financial Instruments	Use of Derivative Financial Instruments Risk Management Objective of Using Derivatives The Company’s use of derivative instruments is limited to the utilization of interest rate swaps to manage interest rate risk exposure on existing and future liabilities and not for speculative purposes. The principal objective of such arrangements is to minimize the risks and related costs associated with the Company’s operating and financial structure. The following table details the Company’s outstanding interest rate swaps as of March 31, 2017 . Interest Rate Trade Date Effective Date Notional Amount Fair Value Pay Fixed Interest Rate Receive Variable Interest Rate Maturity Date PNC Bank, N.A. Sep-14-2012 Oct-10-2012 $ 10,000 $ 12 0.7945 % One-month L Sep-10-2017 Bank of America, N.A. Sep-14-2012 Oct-10-2012 $ 10,000 $ 12 0.7945 % One-month L Sep-10-2017 UBS AG Sep-14-2012 Oct-10-2012 $ 10,000 $ 12 0.7945 % One-month L Sep-10-2017 Royal Bank of Canada Sep-14-2012 Oct-10-2012 $ 10,000 $ 12 0.7945 % One-month L Sep-10-2017 RJ Capital Services, Inc. Sep-14-2012 Oct-10-2012 $ 10,000 $ 12 0.7975 % One-month L Sep-10-2017 Bank of America, N.A. Sep-20-2012 Oct-10-2012 $ 25,000 $ 36 0.7525 % One-month L Sep-10-2017 RJ Capital Services, Inc. Sep-24-2012 Oct-10-2012 $ 25,000 $ 39 0.7270 % One-month L Sep-10-2017 Regions Bank Mar-01-2013 Mar-01-2013 $ 25,000 $ 216 1.3300 % One-month L Feb-14-2020 Capital One, N.A. Jun-13-2013 Jul-01-2013 $ 50,000 $ (66 ) 1.6810 % One-month L Feb-14-2020 Capital One, N.A. Jun-13-2013 Aug-01-2013 $ 25,000 $ (49 ) 1.7030 % One-month L Feb-14-2020 Regions Bank Sep-30-2013 Feb-03-2014 $ 25,000 $ (254 ) 1.9925 % One-month L Feb-14-2020 The Toronto-Dominion Bank Oct-14-2015 Sep-29-2016 $ 25,000 $ 299 1.3830 % One-month L Sep-29-2020 PNC Bank, N.A. Oct-14-2015 Sep-29-2016 $ 50,000 $ 588 1.3906 % One-month L Sep-29-2020 Regions Bank Oct-14-2015 Sep-29-2016 $ 35,000 $ 414 1.3858 % One-month L Sep-29-2020 U.S. Bank, N.A. Oct-14-2015 Sep-29-2016 $ 25,000 $ 290 1.3950 % One-month L Sep-29-2020 Capital One, N.A. Oct-14-2015 Sep-29-2016 $ 15,000 $ 173 1.3950 % One-month L Sep-29-2020 Royal Bank of Canada Jan-08-2015 Mar-20-2015 $ 25,000 $ 81 1.7090 % One-month L Mar-21-2021 The Toronto-Dominion Bank Jan-08-2015 Mar-20-2015 $ 25,000 $ 80 1.7105 % One-month L Mar-21-2021 The Toronto-Dominion Bank Jan-08-2015 Sep-10-2017 $ 100,000 $ (1,159 ) 2.2255 % One-month L Mar-21-2021 Wells Fargo, N.A. Jan-08-2015 Mar-20-2015 $ 25,000 $ 102 1.8280 % One-month L Mar-31-2022 The Toronto-Dominion Bank Jan-08-2015 Feb-14-2020 $ 25,000 $ (71 ) 2.4535 % One-month L Mar-31-2022 Regions Bank Jan-08-2015 Feb-14-2020 $ 50,000 $ (167 ) 2.4750 % One-month L Mar-31-2022 Capital One, N.A. Jan-08-2015 Feb-14-2020 $ 50,000 $ (219 ) 2.5300 % One-month L Mar-31-2022 The fair value of the interest rate swaps outstanding as of March 31, 2017 and December 31, 2016 was as follows. Balance Sheet Line Item (in thousands) Notional Amount March 31, 2017 Fair Value Notional Amount December 31, 2016 Fair Value December 31, 2016 Interest rate swaps-Asset $ 350,000 $ 2,378 $ 300,000 $ 1,471 Interest rate swaps-Liability $ 325,000 $ (1,985 ) $ 375,000 $ (2,438 ) Cash Flow Hedges of Interest Rate Risk The Company’s objectives in using interest rate swaps are to add stability to interest expense and to manage its exposure to interest rate movements. The effective portion of changes in the fair value of derivatives designated and qualified as cash flow hedges is recorded in accumulated other comprehensive loss and will be reclassified to interest expense in the period that the hedged forecasted transaction affects earnings. The ineffective portion of the change in fair value of the derivatives is recognized directly in earnings into interest expense. During the three months ended March 31, 2017 and March 31, 2016 , the Company recorded a gain of $0.2 million and $0 , respectively, of hedge ineffectiveness in earnings due to short-term, partial mismatches in notional amounts. Amounts reported in accumulated other comprehensive loss related to derivatives designated as qualifying cash flow hedges will be reclassified to interest expense as interest payments are made on the Company's variable rate debt. The Company estimates that approximately $1.3 million will be reclassified from accumulated other comprehensive loss as an increase to interest expense over the next 12 months. The table below details the location in the financial statements of the gain or loss recognized on interest rate swaps designated as cash flow hedges for the three months ended March 31, 2017 and March 31, 2016 (in thousands). Three months ended March 31, 2017 2016 Amount of income (loss) recognized in accumulated other comprehensive loss on interest rate swaps (effective portion) $ 514 $ (12,568 ) Amount of loss reclassified from accumulated other comprehensive loss into income (loss) as interest expense (effective portion) $ 698 $ 745 Amount of gain recognized in interest expense (ineffective portion) $ 156 $ — Credit-risk-related Contingent Features The Company has agreements with each of its derivative counterparties that contain a provision where the Company could be declared in default on its derivative obligations if repayment of the underlying indebtedness is accelerated by the lender due to the Company's default on the indebtedness. As of March 31, 2017 , derivatives that were in a net liability position and subject to credit-risk-related contingent features had a termination value of approximately $1.1 million , which includes accrued interest but excludes any adjustment for nonperformance risk. As of March 31, 2017 , the Company had not breached the provisions of these agreements and has not posted any collateral related to these agreements. If the Company had breached any of its provisions at March 31, 2017 , it could have been required to settle its obligations under the agreement of the interest rate swaps in a liability position plus accrued interest for approximately $1.1 million . Fair Value of Interest Rate Swaps The Company’s valuation of the interest rate swaps is determined using widely accepted valuation techniques including discounted cash flow analysis on the expected cash flows of each derivative. This analysis reflects the contractual terms of the derivatives, including the period to maturity, and uses observable market-based inputs including interest rate curves. The Company incorporates credit valuation adjustments to appropriately reflect both its own nonperformance risk and the respective counterparty’s nonperformance risk in the fair value measurements. In adjusting the fair value of its derivative contracts for the effect of nonperformance risk, the Company has considered the impact of netting and any applicable credit enhancements, such as collateral postings, thresholds, mutual puts, and guarantees. Although the Company has determined that the majority of the inputs used to value its derivatives fall within Level 2 of the fair value hierarchy, the credit valuation adjustments associated with its derivatives utilize Level 3 inputs, such as estimates of current credit spreads to evaluate the likelihood of default by itself and its counterparties. However, as of March 31, 2017 and December 31, 2016 , the Company has assessed the significance of the impact of the credit valuation adjustments on the overall valuation of its derivative positions and has determined that the credit valuation adjustments are not significant to the overall valuation of its derivatives. As a result, the Company has determined that its derivative valuations in their entirety are classified in Level 2 of the fair value hierarchy. The following sets forth the Company’s financial instruments that are accounted for at fair value on a recurring basis as of March 31, 2017 and December 31, 2016 . Fair Value Measurements as of Balance Sheet Line Item (in thousands) Fair Value Level 1 Level 2 Level 3 Interest rate swaps-Asset $ 2,378 $ — $ 2,378 $ — Interest rate swaps-Liability $ (1,985 ) $ — $ (1,985 ) $ — Fair Value Measurements as of Balance Sheet Line Item (in thousands) Fair Value December 31, 2016 Level 1 Level 2 Level 3 Interest rate swaps-Asset $ 1,471 $ — $ 1,471 $ — Interest rate swaps-Liability $ (2,438 ) $ — $ (2,438 ) $ —

Equity

Equity	3 Months Ended
	Mar. 31, 2017
Stockholders' Equity Note [Abstract]
Equity	Equity Preferred Stock The table below sets forth the Company’s outstanding preferred stock issuances as of March 31, 2017 Preferred Stock Issuances Issuance Date Number of Shares Liquidation Value Per Share Interest Rate 6.625% Series B Cumulative Redeemable Preferred Stock ("Series B Preferred Stock") April 16, 2013 2,800,000 $ 25.00 6.625 % 6.875% Series C Cumulative Redeemable Preferred Stock ("Series C Preferred Stock") March 17, 2016 3,000,000 $ 25.00 6.875 % The tables below set forth the dividends attributable to the Company's outstanding preferred stock issuances during the three months ended March 31, 2017 and the year ended December 31, 2016 . Quarter Ended 2017 Declaration Date Series B Series C Payment Date March 31 February 15, 2017 $ 0.4140625 $ 0.4296875 March 31, 2017 Total $ 0.4140625 $ 0.4296875 Quarter Ended 2016 Declaration Date Series A Preferred Stock Per Share Series B Preferred Stock Per Share Series C Preferred Stock Per Share Payment Date December 31 November 2, 2016 (1) $ 0.19375 (1) $ 0.4140625 $ 0.4296875 December 30, 2016 September 30 August 1, 2016 0.56250 0.4140625 0.4296875 September 30, 2016 June 30 May 2, 2016 0.56250 0.4140625 0.4965300 (2) June 30, 2016 March 31 February 22, 2016 0.56250 0.4140625 — March 31, 2016 Total $ 1.88125 $ 1.6562500 $ 1.3559050 (1) On November 2, 2016, the Company redeemed all of the outstanding shares of the 9.0% Series A Cumulative Redeemable Preferred Stock, at a cash redemption price of $25.00 per share, plus accrued and unpaid dividends to but excluding the redemption date, without interest. (2) Dividends for the Series C Preferred Stock were accrued and cumulative from and including March 17, 2016 to the first payment date on June 30, 2016. On May 1, 2017 , the Company’s board of directors declared the Series B Preferred Stock and Series C Preferred Stock dividend for the quarter ending June 30, 2017 at a quarterly rate of $0.4140625 per share and $0.4296875 per share, respectively. Common Stock The following sets forth the Company’s at-the market ("ATM") common stock offering program as of March 31, 2017 . ATM Stock Offering Program Date Maximum Aggregate Offering Price (in thousands) Aggregate Common Stock Available as of 2016 $228 million ATM November 8, 2016 $ 228,218 $ 48,788 The table below sets forth the activity for the ATM common stock offering programs during the three months ended March 31, 2017 and the year ended December 31, 2016 , respectively (in thousands, except share data). Three months ended March 31, 2017 ATM Stock Offering Program Shares Weighted Average Price Per Share Gross Sales Net 2016 $228 million ATM 2,843,907 $ 24.10 $ 68,543 $ 941 $ 67,602 Total/weighted average 2,843,907 $ 24.10 $ 68,543 $ 941 $ 67,602 Year ended December 31, 2016 ATM Stock Offering Program Shares Weighted Average Price Per Share Gross Sales Net 2016 $228 million ATM 4,763,838 $ 23.28 $ 110,887 $ 1,550 $ 109,337 2016 $200 million ATM (1) 7,326,200 $ 23.45 171,782 2,429 169,353 Total/weighted average 12,090,038 $ 23.38 $ 282,669 $ 3,979 $ 278,690 (1) This program ended before March 31, 2017 . On April 7, 2017 , the Company entered into a new ATM common stock offering program with a maximum aggregate offering price of up to $300.0 million . Subsequent to March 31, 2017 , the Company sold 5,344,543 shares under its ATM common stock offering programs for gross proceeds of approximately $135.0 million . The net proceeds of approximately $133.4 million were used to fund acquisitions, repay amounts outstanding under the Company's unsecured credit facility, and other general corporate purposes. Dividends The table below sets forth the dividends attributable to the common stock that were declared or paid during the three months ended March 31, 2017 and the year ended December 31, 2016 . Month Ended 2017 Declaration Date Record Date Per Share Payment Date June 30 February 15, 2017 June 30, 2017 $ 0.116667 July 17, 2017 May 31 February 15, 2017 May 31, 2017 0.116667 June 15, 2017 April 30 February 15, 2017 April 28, 2017 0.116667 May 15, 2017 March 31 November 2, 2016 March 31, 2017 0.116667 April 17, 2017 February 28 November 2, 2016 February 28, 2017 0.116667 March 15, 2017 January 31 November 2, 2016 January 31, 2017 0.116667 February 15, 2017 Total $ 0.700002 Month Ended 2016 Declaration Date Record Date Per Share Payment Date December 31 August 1, 2016 December 30, 2016 $ 0.115833 January 17, 2017 November 30 August 1, 2016 November 30, 2016 0.115833 December 15, 2016 October 31 August 1, 2016 October 31, 2016 0.115833 November 15, 2016 September 30 May 2, 2016 September 30, 2016 0.115833 October 17, 2016 August 31 May 2, 2016 August 31, 2016 0.115833 September 15, 2016 July 31 May 2, 2016 July 29, 2016 0.115833 August 15, 2016 June 30 February 22, 2016 June 30, 2016 0.115833 July 15, 2016 May 31 February 22, 2016 May 31, 2016 0.115833 June 15, 2016 April 30 February 22, 2016 April 29, 2016 0.115833 May 16, 2016 March 31 October 22, 2015 March 31, 2016 0.115833 April 15, 2016 February 29 October 22, 2015 February 29, 2016 0.115833 March 15, 2016 January 31 October 22, 2015 January 29, 2016 0.115833 February 16, 2016 Total $ 1.389996 On May 1, 2017 , the Company’s board of directors declared the common stock dividend for the months ending July 31, 2017 , August 31, 2017 and September 30, 2017 to a monthly rate of $0.1175 per share of common stock. Restricted Stock-Based Compensation Restricted shares of common stock granted on January 6, 2017, subject to the recipient’s continued employment, will vest in four equal installments on January 1 of each year beginning in 2018. The following table summarizes activity related to the Company’s unvested restricted shares of common stock for the three months ended March 31, 2017 and the year ended December 31, 2016 . Unvested Restricted Shares of Common Stock Shares Balance at December 31, 2015 271,115 Granted 101,289 (1) Vested (98,746 ) Forfeited (1,321 ) Balance at December 31, 2016 272,337 Granted 75,001 (2) Vested (109,209 ) Forfeited (453 ) Balance at March 31, 2017 237,676 (1) The grant date fair value per share was $17.98 . (2) The grant date fair value per share was $24.41 . The unrecognized compensation expense associated with the Company’s restricted shares of common stock at March 31, 2017 was approximately $4.5 million and is expected to be recognized over a weighted average period of approximately 2.7 years . The following table summarizes the fair value at vesting for the restricted shares of common stock vested during the three months ended March 31, 2017 and March 31, 2016 . Three months ended March 31, 2017 2016 Vested restricted shares of common stock 109,209 84,336 Fair value of vested restricted shares of common stock (in thousands) $ 2,615 $ 1,522

Noncontrolling Interest

Noncontrolling Interest	3 Months Ended
	Mar. 31, 2017
Noncontrolling Interest [Abstract]
Noncontrolling Interest	Noncontrolling Interest The table below summarizes the activity for noncontrolling interest in the Company for the three months ended March 31, 2017 and the year ended December 31, 2016 . LTIP Units Other Common Units Total Noncontrolling Common Units Noncontrolling Interest Balance at December 31, 2015 1,610,105 1,915,872 3,525,977 4.9 % Granted/Issued 176,396 — 176,396 N/A Forfeited — — — N/A Conversions from LTIP units to Other Common Units (209,985 ) 209,985 — N/A Redemptions from Other Common Units to common stock — (68,492 ) (68,492 ) N/A Balance at December 31, 2016 1,576,516 2,057,365 3,633,881 4.3 % Granted/Issued 126,239 — 126,239 N/A Forfeited — — — N/A Conversions from LTIP units to Other Common Units (75,854 ) 75,854 — N/A Redemptions from Other Common Units to common stock — (145,029 ) (145,029 ) N/A Balance at March 31, 2017 1,626,901 1,988,190 3,615,091 4.2 % LTIP Units LTIP units granted on January 6, 2017 to independent directors, subject to the recipient’s continued service, will vest on January 1, 2018. LTIP units granted on January 6, 2017 to certain senior executive officers and senior employees, subject to the recipient’s continued employment, will vest quarterly over four years, with the first vesting date being March 31, 2017. The fair value of the LTIP units at the date of grant was determined by a lattice-binomial option-pricing model based on a Monte Carlo simulation. The fair value of the LTIP units are based on Level 3 inputs and are non-recurring fair value measurements. The table below sets forth the assumptions used in valuing such LTIP units granted during the three months ended March 31, 2017 . LTIP Units Assumptions Grant date January 6, 2017 Expected term (years) 10 Expected volatility 23.0 % Expected dividend yield 6.0 % Risk-free interest rate 1.61 % Fair value of LTIP units at issuance (in thousands) $ 2,924 LTIP units at issuance 126,239 Fair value unit price per LTIP unit at issuance $ 23.16 The following table summarizes activity related to the Company’s unvested LTIP units for the three months ended March 31, 2017 and the year ended December 31, 2016 . Unvested LTIP Units LTIP Units Balance at December 31, 2015 534,910 Granted 176,396 Vested (307,883 ) Forfeited — Balance at December 31, 2016 403,423 Granted 126,239 Vested (67,670 ) Forfeited — Balance at March 31, 2017 461,992 The unrecognized compensation expense associated with the Company’s LTIP units at March 31, 2017 was approximately $8.3 million and is expected to be recognized over a weighted average period of approximately 2.7 years . The following table summarizes the fair value at vesting for the LTIP units vested during the three months ended March 31, 2017 and March 31, 2016 . Three months ended March 31, 2017 2016 Vested LTIP units 67,670 170,277 Fair value of vested LTIP units (in thousands) $ 1,664 $ 3,089

Equity Incentive Plan

Equity Incentive Plan	3 Months Ended
	Mar. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Equity Incentive Plan	Equity Incentive Plan On January 6, 2017, the Company granted performance units approved by the compensation committee of the board of directors, under the 2011 Plan to provide certain key employees of the Company with incentives designed to align those key employees' interests more closely with those of the stockholders. The ultimate value of the performance units depends on the Company’s total stockholder return ("TSR") over a three -year period commencing January 1, 2017 and ends on December 31, 2019 (the "measuring period"). At the end of the measuring period, the performance units convert into shares of common stock, or, at the Company's election and with the award recipient's consent, LTIP units or other securities, at a rate depending on the Company’s TSR over the measuring period as compared to three different benchmarks and on the absolute amount of the Company’s TSR. A recipient of the performance units may receive as few as zero shares or as many as 250% of the number of target units, plus deemed dividends. The target amount of the performance units is nominally allocated as: i) 25% to the Company’s TSR compared to the TSR of an industry peer group; ii) 25% to the Company’s TSR compared to the TSR of a size-based peer group; and iii) 50% to the Company’s TSR compared to the TSR of the companies in the MSCI US REIT index. No dividends are paid to the recipient during the measuring period. At the end of the measuring period, if the Company’s TSR is such that the recipient earns shares of common stock or, at the Company's election and with the award recipient's consent, LTIP units or other securities (“Award Shares”), the recipient will receive additional Award Shares relating to dividends deemed to have been paid and reinvested on the Award Shares. The Company, in the discretion of the compensation committee of the board of directors, may pay the cash value of the deemed dividends instead of issuing additional Award Shares. The number of Award Shares is determined at the end of the measuring period, and one-half of the Award Shares and all dividend shares vest immediately. The other one-half of the Award Shares will be restricted (subject to forfeiture) and vest one year after the end of the measuring period. The fair value of the performance units at the date of grant was determined by a lattice-binomial option-pricing model based on a Monte Carlo simulation. The fair value of the performance units are based on Level 3 inputs and are non-recurring fair value measurements. The table below sets forth the assumptions used in valuing the performance units granted during the three months ended March 31, 2017 . Performance Units Assumptions Grant date January 6, 2017 Expected volatility 23.0 % Expected dividend yield 6.0 % Risk-free interest rate 1.61 % Fair value of performance units grant (in thousands) $ 2,882 The performance unit equity compensation expense is recognized into earnings ratably from the grant date over the respective vesting periods. The unrecognized compensation expense associated with the Company's performance units and outperformance program (collectively, "Performance-based Compensation Plans") at March 31, 2017 was approximately $4.7 million and is expected to be recognized over a weighted average period of approximately 2.7 years . Non-cash Compensation Expense The following table summarizes the amount recorded in general and administrative expenses in the accompanying Consolidated Statements of Operations for the amortization of restricted shares of common stock, LTIP units, Performance-based Compensation Plans, and the Company’s board of directors’ compensation for the three months ended March 31, 2017 and March 31, 2016 . Three months ended March 31, Non-Cash Compensation Expense (in thousands) 2017 2016 Restricted shares of common stock $ 592 $ 558 LTIP units 1,170 2,795 (1) Performance-based Compensation Plans 537 172 Board of directors compensation (2) 88 80 Total non-cash compensation expense $ 2,387 $ 3,605 (1) Inclusive of approximately $1.6 million of non-cash compensation expense during the three months ended March 31, 2016 associated with the severance cost of a former executive officer. (2) All of the Company’s independent directors elected to receive shares of common stock in lieu of cash for their service during the three months ended March 31, 2017 and March 31, 2016 . The number of shares of common stock granted is calculated based on the trailing 10 days average common stock price ending on the third business day preceding the grant date.

Earnings Per Share

Earnings Per Share	3 Months Ended
	Mar. 31, 2017
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Share During the three months ended March 31, 2017 and March 31, 2016 , there were 239,827 and 285,458 , respectively, unvested shares of restricted stock on a weighted average basis that were considered participating securities. The following tables set forth the computation of basic and diluted earnings per common share for the three months ended March 31, 2017 and March 31, 2016 . Three months ended March 31, Earnings Per Share (in thousands, except share data) 2017 2016 Numerator Net income $ 69 $ 12,332 Less: preferred stock dividends 2,448 2,912 Less: amount allocated to participating securities 83 100 Less: income (loss) attributable to noncontrolling interest after preferred stock dividends (103 ) 482 Net income (loss) attributable to common stockholders $ (2,359 ) $ 8,838 Denominator Weighted average common shares outstanding — basic 81,807,883 67,889,217 Effect of dilutive securities (1) Unvested shares of restricted common stock — 43,529 Unvested Performance-based Compensation Plans — 31,813 Weighted average common shares outstanding — diluted 81,807,883 67,964,559 Net income (loss) per share — basic and diluted Net income (loss) per share attributable to common stockholders — basic $ (0.03 ) $ 0.13 Net income (loss) per share attributable to common stockholders — diluted $ (0.03 ) $ 0.13 (1) During the three months ended March 31, 2017 , there were 239,827 unvested shares of restricted common stock on a weighted average basis and 437,527 unvested performance units on a weighted average basis that were not included in the computation of diluted earnings per share because to do so would have been antidilutive for the period.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies The Company is subject to various legal proceedings and claims that arise in the ordinary course of business. These matters are generally covered by insurance subject to deductible requirements. Management believes that the ultimate settlement of these actions will not have a material adverse effect on the Company’s financial position, results of operations, or cash flows. The Company is subject to a one-time incentive fee based on aggregate performance thresholds of the acquired buildings sourced by Columbus Nova Real Estate Acquisition Group, LLC. As of March 31, 2017 and December 31, 2016 , the fair value of the incentive fee was zero . The fair value was calculated using the following key Level 3 inputs: discount rates of 8.5% to 12.0% and 8.0% to 12.0% as of March 31, 2017 and December 31, 2016 , respectively, and exit capitalization rates of 7.5% to 12.0% and 7.0% to 12.0% as of March 31, 2017 and December 31, 2016 , respectively. The Company has letters of credit of approximately $3.4 million related to development projects and its corporate office lease as of March 31, 2017 .

Subsequent Events

Subsequent Events	3 Months Ended
	Mar. 31, 2017
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events The following non-recognized subsequent events were noted. Subsequent to March 31, 2017 , the Company acquired three buildings of approximately 0.5 million square feet for an aggregate contractual purchase price of approximately $20.6 million . Management has not finalized the acquisition accounting and therefore is not able to provide the disclosures otherwise required by GAAP.

Summary of Significant Accoun19

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2017
Accounting Policies [Abstract]
Quarterly Financial Information	Interim Financial Information The accompanying interim financial statements have been presented in conformity with accounting principles generally accepted in the United States of America (“GAAP”) and with the instructions to Form 10-Q and Regulation S-X for interim financial information. Accordingly, these statements do not include all of the information and notes required by GAAP for complete financial statements. In the opinion of management, the accompanying interim financial statements include all adjustments, consisting of normal recurring items, necessary for their fair statement in conformity with GAAP. Interim results are not necessarily indicative of results for a full year. The year-end consolidated balance sheet data was derived from audited financial statements, but does not include all disclosures required by GAAP. The information included in this Quarterly Report on Form 10-Q should be read in conjunction with the Company’s consolidated financial statements and notes thereto contained in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2016 .
Related-Party Transactions	Related Parties As of March 31, 2017 and December 31, 2016 , the Company had approximately $31,000 and $48,000 , respectively, of amounts due from related parties, which are included in prepaid expenses and other assets on the accompanying Consolidated Balance Sheets.
Basis of Presentation	Basis of Presentation The Company’s consolidated financial statements include the accounts of the Company, the Operating Partnership and their subsidiaries. Interests in the Operating Partnership not owned by the Company are referred to as “Noncontrolling Common Units.” These Noncontrolling Common Units are held by other limited partners in the form of common units ("Other Common Units") and long term incentive plan units (“LTIP units”) issued pursuant to the STAG Industrial, Inc. 2011 Equity Incentive Plan, as amended (the “2011 Plan”). All significant intercompany balances and transactions have been eliminated in the consolidation of entities. The financial statements of the Company are presented on a consolidated basis for all periods presented.
Accounting Changes and Error Corrections	Revision of Previously Reported Consolidated Financial Statements In connection with the preparation of the Company's consolidated financial statements for the year ended December 31, 2016, the Company identified an error in the estimated useful life of a building acquired in the fourth quarter of 2014. As a result of the error, depreciation expense had been overstated and thereby rental property, net and equity were understated. The Company concluded that the amounts were not material to any of its previously issued consolidated financial statements. Accordingly, the Company revised these balances in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2016 . These adjustments do not impact the Company’s cash balances for any of the reporting periods. The effects of this revision to the prior period consolidated financial statements are as follows (in thousands, except for per share data). Effect of Revision as of and for the Three Months Ended March 31, 2016 As Previously Reported Adjustment As Revised Consolidated Balance Sheet, March 31, 2016 Total equity $ 903,510 $ 3,009 $ 906,519 Consolidated Statement of Operations, Three Months Ended March 31, 2016 Depreciation and amortization $ 30,280 $ (531 ) $ 29,749 Total expenses $ 54,766 $ (531 ) $ 54,235 Net income $ 11,801 $ 531 $ 12,332 Net income attributable to STAG Industrial, Inc. $ 11,346 $ 504 $ 11,850 Net income attributable to common stockholders $ 8,334 $ 504 $ 8,838 Net income per share attributable to common stockholders — basic and diluted $ 0.12 $ 0.01 $ 0.13 Consolidated Statement of Comprehensive Income (Loss), Three Months Ended March 31, 2016 Comprehensive income (loss) $ (22 ) $ 531 $ 509
Reclassification	Certain prior year amounts have been reclassified to conform to the current year presentation.
Adoption of New Accounting Pronouncements	In February of 2017, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2017-05, Other Income - Gains and Losses from the Derecognition of Nonfinancial Assets (Subtopic 610-20): Clarifying the Scope of Asset Derecognition Guidance and Accounting for Partial Sales of Nonfinancial Assets , which provides guidance for recognizing gains and losses from the transfer of nonfinancial assets in contracts with non-customers. The new standard was issued as part of the new revenue standard (ASU 2014-09, as discussed below), and defines “in substance nonfinancial asset,” unifies guidance related to partial sales of nonfinancial assets, eliminates rules specifically addressing sales of real estate, removes exceptions to the financial asset derecognition model, and clarifies the accounting for contributions of nonfinancial assets to joint ventures. As a result of the new guidance, the guidance specific to real estate sales in Subtopic 360-20 will be eliminated, and sales and partial sales of real estate assets will now be subject to the same derecognition model as all other nonfinancial assets. This standard is effective at the same time an entity adopts ASU 2014-09, and either the full retrospective approach or the modified retrospective approach may be used. The adoption of ASU 2017-05 is not expected to materially impact the Company’s consolidated financial statements. The Company plans to adopt this standard effective January 1, 2018. In January of 2017, the FASB issued ASU 2017-04, Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment . The new standard removes Step 2 of the goodwill impairment test, which requires a hypothetical purchase price allocation. A goodwill impairment will now be the amount by which a reporting unit’s carrying value exceeds its fair value, not to exceed the carrying amount of goodwill. This standard is effective for annual or any interim goodwill impairment tests in fiscal years beginning after December 15, 2019, with early adoption permitted. The Company elected to early adopt this standard effective January 1, 2017. The adoption of this standard did not have a material effect on the Company's consolidated financial statements. In January of 2017, the FASB issued ASU 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business . The new standard provides a screen to determine when a set of assets and activities is not a business. The screen requires that when substantially all of the fair value of the gross assets acquired or disposed of is concentrated in a single identifiable asset or a group of similar identifiable assets, the set is not a business. This standard is effective for annual periods beginning after December 15, 2017 and interim periods within those periods, with early adoption permitted, and should be applied prospectively on or after the effective date. Upon the adoption of ASU 2017-01, it is expected that the majority of the Company's acquisitions will be accounted for as asset acquisitions, whereas under the current guidance the majority of the Company's acquisitions have been accounted for as business combinations. The most significant difference between the two accounting models that will impact the Company's consolidated financial statements is that in an asset acquisition, property acquisition costs are generally a component of the consideration transferred to acquire a group of assets and are capitalized as a component of the cost of the assets, whereas in a business combination, property acquisition costs are expensed and not included as part of the consideration transferred. The Company plans to adopt this standard effective January 1, 2018. In November of 2016, the FASB issued ASU 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash . The new standard requires that the statement of cash flows explain the changes during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. This standard is effective for fiscal years beginning after December 15, 2017 and interim periods within those years, with early adoption permitted, and should be applied using a retrospective transition method to each period presented. Upon the adoption of ASU 2016-18, the Company will reconcile both cash and cash equivalents and restricted cash in the accompanying Statements of Cash Flows, whereas under the current guidance the Company explains the changes during the period for cash and cash equivalents only. The Company expects that it will adopt the standard effective January 1, 2018. In August of 2016, the FASB issued ASU 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments , which provides clarified guidance on the presentation and classification of certain cash receipts and cash payments in the statement of cash flows. This standard is effective for fiscal years beginning after December 15, 2017, and interim periods within those years, with early adoption permitted. The Company elected to early adopt this standard effective July 1, 2016, and the effects of this standard were applied retrospectively to all prior periods presented. The effect of the change in accounting principle was an increase in net cash provided by operating activities of approximately $1.1 million for the three months ended March 31, 2016 and a corresponding increase in net cash used in financing activities for the three months ended March 31, 2016 related to the payment of loan prepayment fees and costs. In February of 2016, the FASB issued ASU 2016-02, Leases (Topic 842) , which sets out the principles for the recognition, measurement, presentation and disclosure of leases for both parties to a contract (i.e. lessees and lessors). Topic 842 supersedes the previous leases standard, Topic 840, Leases . 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 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. ASU 2016-02 is expected to impact the Company’s consolidated financial statements as the Company has certain operating and land lease arrangements for which it is the lessee, which will result in the recording of a right of use asset and the related lease liability. The standard is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years, with early adoption permitted. The new standard must be adopted using a modified retrospective transition and will require application of the new guidance at the beginning of the earliest comparative period. The Company is currently in the process of evaluating the impact the adoption of ASU 2016-02 will have on the Company’s financial position or results of operations, and expects to adopt the standard effective January 1, 2019. In January of 2016, the FASB issued ASU 2016-01, Recognition and Measurement of Financial Assets and Financial Liabilities (Subtopic 825-10) . The amendments in ASU 2016-01 address certain aspects of recognition, measurement, presentation, and disclosure of financial instruments. The standard primarily affects the accounting for equity investments, financial liabilities under the fair value option, and the presentation and disclosure requirements for financial instruments. ASU 2016-01 is effective for the annual periods beginning after December 31, 2017 and for annual periods and interim periods within those years. Early adoption is permitted for all financial statements of fiscal years and interim periods that have not yet been issued. The adoption of ASU 2016-01 is not expected to materially impact the Company’s consolidated financial statements. The Company expects that it will adopt the standard effective January 1, 2018. In May of 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers (Topic 606) . ASU 2014-09 is a comprehensive new revenue recognition model requiring a company to recognize revenue to depict the transfer of goods or services to a customer at an amount reflecting the consideration it expects to receive in exchange for those goods or services. While lease contracts with customers, which constitute a vast majority of the Company's revenues, are specifically excluded from the model's scope, certain of the Company's revenue streams may be impacted by the new guidance. Once the new guidance setting forth principles for the recognition, measurement, presentation and disclosure of leases (ASU 2016-02, as discussed above) goes into effect, the new revenue standard may apply to executory costs and other components of revenue due under leases that are deemed to be non-lease components (such as common area maintenance and provision of utilities), even when the revenue for such activities is not separately stipulated in the lease. In that case, revenue from these items 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 the total revenue recognized over time would not differ under the new guidance, the recognition pattern would be different. The Company is in the process of evaluating the significance of the difference in the recognition pattern that would result from this change. In adopting ASU 2014-09, companies may use either a full retrospective or a modified retrospective approach. The Company has not decided which method of adoption it will use. Additionally, this guidance requires improved disclosures regarding the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers. ASU 2014-09 is effective for the first interim period within annual reporting periods beginning after December 15, 2017. Early adoption is permitted for the first interim period within annual reporting periods beginning after December 15, 2016. The Company is currently in the process of evaluating the impact the adoption of ASU 2014-09 will have on the Company’s financial position or results of operations, and expects that it will adopt the standard effective January 1, 2018.

Summary of Significant Accoun20

Summary of Significant Accounting Policies Summary of Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2017
Accounting Policies [Abstract]
Schedule of Error Corrections and Prior Period Adjustments [Table Text Block]	The Company concluded that the amounts were not material to any of its previously issued consolidated financial statements. Accordingly, the Company revised these balances in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2016 . These adjustments do not impact the Company’s cash balances for any of the reporting periods. The effects of this revision to the prior period consolidated financial statements are as follows (in thousands, except for per share data). Effect of Revision as of and for the Three Months Ended March 31, 2016 As Previously Reported Adjustment As Revised Consolidated Balance Sheet, March 31, 2016 Total equity $ 903,510 $ 3,009 $ 906,519 Consolidated Statement of Operations, Three Months Ended March 31, 2016 Depreciation and amortization $ 30,280 $ (531 ) $ 29,749 Total expenses $ 54,766 $ (531 ) $ 54,235 Net income $ 11,801 $ 531 $ 12,332 Net income attributable to STAG Industrial, Inc. $ 11,346 $ 504 $ 11,850 Net income attributable to common stockholders $ 8,334 $ 504 $ 8,838 Net income per share attributable to common stockholders — basic and diluted $ 0.12 $ 0.01 $ 0.13 Consolidated Statement of Comprehensive Income (Loss), Three Months Ended March 31, 2016 Comprehensive income (loss) $ (22 ) $ 531 $ 509

Rental Property (Tables)

Rental Property (Tables)	3 Months Ended
	Mar. 31, 2017
Real Estate [Abstract]
Schedule of components of rental property	The following table summarizes the components of rental property as of March 31, 2017 and December 31, 2016 . Rental Property (in thousands) March 31, 2017 December 31, 2016 Land $ 281,756 $ 272,162 Buildings, net of accumulated depreciation of $134,236 and $125,971, respectivel y 1,468,933 1,408,406 Tenant improvements, net of accumulated depreciation of $29,748 and $28,388, respectively 24,846 24,974 Building and land improvements, net of accumulated depreciation of $38,111 and $33,054, respectivel y 110,937 107,463 Construction in progress 2,892 9,298 Deferred leasing intangibles, net of accumulated amortization of $251,089 and $237,456, respectively 289,275 294,533 Total rental property, net $ 2,178,639 $ 2,116,836
Schedule of real estate properties acquired	The following table summarizes the acquisitions of the Company during the three months ended March 31, 2017 . Location of Property Square Feet Buildings Purchase Price Jacksonville, FL 1,025,720 4 $ 34,264 Sparks, NV 174,763 1 8,380 Salisbury, NC 288,000 1 8,250 Franklin Township, NJ 183,000 1 12,800 Milford, CT 200,000 1 12,762 Bedford Heights, OH 173,034 1 7,622 Redford, MI 135,728 1 7,769 Warren, MI 154,377 1 7,940 Three months ended March 31, 2017 2,334,622 11 $ 99,787
Summary of allocation of the consideration paid for the acquired assets and liabilities in connection with the acquisition of buildings at the date of acquisition	The following table summarizes the allocation of the consideration paid at the date of acquisition during the three months ended March 31, 2017 for the acquired assets and liabilities in connection with the acquisitions identified in the table above. Acquired Assets and Liabilities Purchase Price (in thousands) Weighted Average Amortization Period (years) of Intangibles at Acquisition Land $ 10,447 N/A Buildings 66,647 N/A Tenant improvements 1,720 N/A Building and land improvements 5,875 N/A Deferred leasing intangibles - In-place leases 9,342 5.4 Deferred leasing intangibles - Tenant relationships 4,383 8.6 Deferred leasing intangibles - Above market leases 1,842 4.8 Deferred leasing intangibles - Below market leases (469 ) 7.5 Total purchase price $ 99,787
Schedule of pro forma information for acquired properties	The table below sets forth the results of operations for the three months ended March 31, 2017 , for the properties acquired during the three months ended March 31, 2017 , included in the Company’s Consolidated Statements of Operations from the date of acquisition. Results of Operations (in thousands) Three months ended March 31, 2017 Total revenue $ 1,437 Property acquisition costs $ 593 Net loss $ 669 The following tables set forth pro forma information for the three months ended March 31, 2017 and March 31, 2016 . The below pro forma information does not purport to represent what the actual results of operations of the Company would have been had the acquisitions outlined above occurred on the first day of the applicable reporting period, nor do they purport to predict the results of operations of future periods. The pro forma information has not been adjusted for property sales. Pro Forma (in thousands) (1) Three months ended March 31, 2017 Three months ended March 31, 2016 Total revenue $ 70,523 $ 63,504 Net income (2) $ 1,093 $ 12,216 Net income (loss) attributable to common stockholders $ (1,379 ) $ 8,727 (1) The unaudited pro forma information for the three months ended March 31, 2017 and March 31, 2016 is presented as if the properties acquired during the three months ended March 31, 2017 and March 31, 2016 were completed on January 1, 2016 and January 1, 2015 , respectively. (2) The net income for the three months ended March 31, 2017 excludes approximately $0.6 million of property acquisition costs related to the acquisition of buildings that closed during the three months ended March 31, 2017 , and the net income for the three months ended March 31, 2016 was adjusted to include these acquisition costs. Net income for the three months ended March 31, 2016 excludes approximately $0.5 million of property acquisition costs related to the acquisition of buildings that closed during the three months ended March 31, 2016 .
Schedule of Finite-Lived Intangible Assets and Below Market Leases	The following table summarizes the deferred leasing intangibles on the accompanying Consolidated Balance Sheets as of March 31, 2017 and December 31, 2016 . March 31, 2017 December 31, 2016 Deferred Leasing Intangibles (in thousands) Gross Accumulated Amortization Net Gross Accumulated Amortization Net Above market leases $ 71,805 $ (34,594 ) $ 37,211 $ 70,668 $ (32,868 ) $ 37,800 Other intangible lease assets 468,559 (216,495 ) 252,064 461,321 (204,588 ) 256,733 Total deferred leasing intangible assets $ 540,364 $ (251,089 ) $ 289,275 $ 531,989 $ (237,456 ) $ 294,533 Below market leases $ 31,117 $ (11,443 ) $ 19,674 $ 30,791 $ (10,450 ) $ 20,341 Total deferred leasing intangible liabilities $ 31,117 $ (11,443 ) $ 19,674 $ 30,791 $ (10,450 ) $ 20,341 The following table sets forth the amortization expense and the net decrease to rental income for the amortization of deferred leasing intangibles during the three months ended March 31, 2017 and March 31, 2016 . Three months ended March 31, Deferred Leasing Intangibles Amortization (in thousands) 2017 2016 Net decrease to rental income related to above and below market lease amortization $ 1,296 $ 1,666 Amortization expense related to other intangible lease assets $ 18,393 $ 15,913
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense	The following table sets forth the amortization of deferred leasing intangibles over the next five years as of March 31, 2017 . Year Amortization Expense Related to Other Intangible Lease Assets (in thousands) Net Decrease to Rental Income Related to Above and Below Market Lease Amortization (in thousands) Remainder of 2017 $ 48,836 $ 3,703 2018 $ 52,556 $ 3,748 2019 $ 40,064 $ 3,011 2020 $ 31,464 $ 2,587 2021 $ 22,206 $ 1,404
Below Market Lease, Future Amortization Income	The following table sets forth the amortization of deferred leasing intangibles over the next five years as of March 31, 2017 . Year Amortization Expense Related to Other Intangible Lease Assets (in thousands) Net Decrease to Rental Income Related to Above and Below Market Lease Amortization (in thousands) Remainder of 2017 $ 48,836 $ 3,703 2018 $ 52,556 $ 3,748 2019 $ 40,064 $ 3,011 2020 $ 31,464 $ 2,587 2021 $ 22,206 $ 1,404

Debt (Tables)

Debt (Tables)	3 Months Ended
	Mar. 31, 2017
Debt Disclosure [Abstract]
Interest Income and Interest Expense Disclosure [Table Text Block]	The table below sets forth the costs included in interest expense related to the Company's debt arrangements on the accompanying Consolidated Statement of Operations for the three months ended March 31, 2017 and March 31, 2016 . Three months ended March 31, Costs Included in Interest Expense (in thousands) 2017 2016 Amortization of deferred financing fees and debt issuance costs $ 526 $ 474 Facility fees - unsecured credit facility $ 238 $ 240
Summary of the mortgage notes payable, unsecured term loans and credit facility	The following table sets forth a summary of the Company’s outstanding indebtedness, including borrowings under the Company’s unsecured credit facility, unsecured term loans, unsecured notes, and mortgage notes as of March 31, 2017 and December 31, 2016 . Loan Principal Outstanding as of March 31, 2017 (in thousands) Principal Outstanding as of December 31, 2016 (in thousands) Interest (1) Current Maturity Prepayment Terms (2) Unsecured credit facility: Unsecured Credit Facility (3) $ 71,000 $ 28,000 L + 1.15% Dec-18-2019 i Total unsecured credit facility 71,000 28,000 Unsecured term loans: Unsecured Term Loan C 150,000 150,000 L + 1.30% Sep-29-2020 i Unsecured Term Loan B 150,000 150,000 L + 1.30% Mar-21-2021 i Unsecured Term Loan A 150,000 150,000 L + 1.30% Mar-31-2022 i Total unsecured term loans 450,000 450,000 Less: Total unamortized deferred financing fees and debt issuance costs (3,234 ) (3,392 ) Total carrying value unsecured term loans 446,766 446,608 Unsecured notes: Series F Unsecured Notes 100,000 100,000 3.98 % Jan-05-2023 ii Series A Unsecured Notes 50,000 50,000 4.98 % Oct-1-2024 ii Series D Unsecured Notes 100,000 100,000 4.32 % Feb-20-2025 ii Series B Unsecured Notes 50,000 50,000 4.98 % Jul-1-2026 ii Series C Unsecured Notes 80,000 80,000 4.42 % Dec-30-2026 ii Series E Unsecured Notes 20,000 20,000 4.42 % Feb-20-2027 ii Total unsecured notes 400,000 400,000 Less: Total unamortized deferred financing fees and debt issuance costs (1,967 ) (2,034 ) Total carrying value unsecured notes 398,033 397,966 Mortgage notes payable (secured debt): Union Fidelity Life Insurance Company — 5,384 5.81 % Apr-30-2017 iii Webster Bank, National Association — 2,853 3.66 % May-29-2017 iv Webster Bank, National Association — 3,073 3.64 % May-31-2017 iv Wells Fargo, National Association 4,024 4,043 5.90 % Aug-1-2017 v Connecticut General Life Insurance Company -1 Facility 35,167 35,320 6.50 % Feb-1-2018 vi Connecticut General Life Insurance Company -2 Facility 36,717 36,892 5.75 % Feb-1-2018 vi Connecticut General Life Insurance Company -3 Facility 16,073 16,141 5.88 % Feb-1-2018 vi Wells Fargo Bank, National Association CMBS Loan 56,192 56,608 4.31 % Dec-1-2022 vii Thrivent Financial for Lutherans 3,986 4,012 4.78 % Dec-15-2023 iv Total mortgage notes 152,159 164,326 Total unamortized fair market value premiums 80 112 Less: Total unamortized deferred financing fees and debt issuance costs (787 ) (873 ) Total carrying value mortgage notes 151,452 163,565 Total / weighted average interest rate (4) $ 1,067,251 $ 1,036,139 3.68 % (1) Current interest rate as of March 31, 2017 . At March 31, 2017 , the one-month LIBOR (“L”) was 0.98278% . The current interest rate is not adjusted to include the amortization of deferred financing fees or debt issuance costs incurred in obtaining debt or any unamortized fair market value premiums. The spread over the applicable rate for the Company's unsecured credit facility and unsecured term loans is based on the Company's consolidated leverage ratio, as defined in the respective loan agreements. (2) Prepayment terms consist of (i) pre-payable with no penalty; (ii) pre-payable with penalty; (iii) pre-payable without penalty two months prior to the maturity date; (iv) pre-payable without penalty three months prior to the maturity date; (v) pre-payable without penalty three months prior to the maturity date, however can be defeased; (vi) pre-payable without penalty six months prior to the maturity date; and (vii) pre-payable without penalty three months prior to the maturity date, however can be defeased beginning January 1, 2016. (3) The capacity of the unsecured credit facility is currently $450.0 million . Deferred financing fees and debt issuance costs, net of accumulated amortization related to the unsecured credit facility of approximately $2.1 million and $2.3 million is included in prepaid expenses and other assets on the accompanying Consolidated Balance Sheets as of March 31, 2017 and December 31, 2016 , respectively. (4) The weighted average interest rate was calculated using the fixed interest rate swapped on the current notional amount of $450.0 million of debt, and is not adjusted to include the amortization of deferred financing fees or debt issuance costs incurred in obtaining debt or any unamortized fair market value premiums.
Schedule of aggregate carrying value of the debt and the corresponding estimate of fair value	The following table presents the aggregate principal outstanding of the Company’s debt and the corresponding estimate of fair value as of March 31, 2017 and December 31, 2016 (in thousands). March 31, 2017 December 31, 2016 Principal Outstanding Fair Value Principal Outstanding Fair Value Unsecured credit facility $ 71,000 $ 71,000 $ 28,000 $ 28,000 Unsecured term loans 450,000 450,000 450,000 450,000 Unsecured notes 400,000 413,928 400,000 399,091 Mortgage notes 152,159 154,133 164,326 166,099 Total principal amount 1,073,159 $ 1,089,061 1,042,326 $ 1,043,190 Add: Total unamortized fair market value premiums 80 112 Less: Total unamortized deferred financing fees and debt issuance costs (5,988 ) (6,299 ) Total carrying value $ 1,067,251 $ 1,036,139

Use of Derivative Financial I23

Use of Derivative Financial Instruments (Tables)	3 Months Ended
	Mar. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of interest rate swaps	The fair value of the interest rate swaps outstanding as of March 31, 2017 and December 31, 2016 was as follows. Balance Sheet Line Item (in thousands) Notional Amount March 31, 2017 Fair Value Notional Amount December 31, 2016 Fair Value December 31, 2016 Interest rate swaps-Asset $ 350,000 $ 2,378 $ 300,000 $ 1,471 Interest rate swaps-Liability $ 325,000 $ (1,985 ) $ 375,000 $ (2,438 ) The following table details the Company’s outstanding interest rate swaps as of March 31, 2017 . Interest Rate Trade Date Effective Date Notional Amount Fair Value Pay Fixed Interest Rate Receive Variable Interest Rate Maturity Date PNC Bank, N.A. Sep-14-2012 Oct-10-2012 $ 10,000 $ 12 0.7945 % One-month L Sep-10-2017 Bank of America, N.A. Sep-14-2012 Oct-10-2012 $ 10,000 $ 12 0.7945 % One-month L Sep-10-2017 UBS AG Sep-14-2012 Oct-10-2012 $ 10,000 $ 12 0.7945 % One-month L Sep-10-2017 Royal Bank of Canada Sep-14-2012 Oct-10-2012 $ 10,000 $ 12 0.7945 % One-month L Sep-10-2017 RJ Capital Services, Inc. Sep-14-2012 Oct-10-2012 $ 10,000 $ 12 0.7975 % One-month L Sep-10-2017 Bank of America, N.A. Sep-20-2012 Oct-10-2012 $ 25,000 $ 36 0.7525 % One-month L Sep-10-2017 RJ Capital Services, Inc. Sep-24-2012 Oct-10-2012 $ 25,000 $ 39 0.7270 % One-month L Sep-10-2017 Regions Bank Mar-01-2013 Mar-01-2013 $ 25,000 $ 216 1.3300 % One-month L Feb-14-2020 Capital One, N.A. Jun-13-2013 Jul-01-2013 $ 50,000 $ (66 ) 1.6810 % One-month L Feb-14-2020 Capital One, N.A. Jun-13-2013 Aug-01-2013 $ 25,000 $ (49 ) 1.7030 % One-month L Feb-14-2020 Regions Bank Sep-30-2013 Feb-03-2014 $ 25,000 $ (254 ) 1.9925 % One-month L Feb-14-2020 The Toronto-Dominion Bank Oct-14-2015 Sep-29-2016 $ 25,000 $ 299 1.3830 % One-month L Sep-29-2020 PNC Bank, N.A. Oct-14-2015 Sep-29-2016 $ 50,000 $ 588 1.3906 % One-month L Sep-29-2020 Regions Bank Oct-14-2015 Sep-29-2016 $ 35,000 $ 414 1.3858 % One-month L Sep-29-2020 U.S. Bank, N.A. Oct-14-2015 Sep-29-2016 $ 25,000 $ 290 1.3950 % One-month L Sep-29-2020 Capital One, N.A. Oct-14-2015 Sep-29-2016 $ 15,000 $ 173 1.3950 % One-month L Sep-29-2020 Royal Bank of Canada Jan-08-2015 Mar-20-2015 $ 25,000 $ 81 1.7090 % One-month L Mar-21-2021 The Toronto-Dominion Bank Jan-08-2015 Mar-20-2015 $ 25,000 $ 80 1.7105 % One-month L Mar-21-2021 The Toronto-Dominion Bank Jan-08-2015 Sep-10-2017 $ 100,000 $ (1,159 ) 2.2255 % One-month L Mar-21-2021 Wells Fargo, N.A. Jan-08-2015 Mar-20-2015 $ 25,000 $ 102 1.8280 % One-month L Mar-31-2022 The Toronto-Dominion Bank Jan-08-2015 Feb-14-2020 $ 25,000 $ (71 ) 2.4535 % One-month L Mar-31-2022 Regions Bank Jan-08-2015 Feb-14-2020 $ 50,000 $ (167 ) 2.4750 % One-month L Mar-31-2022 Capital One, N.A. Jan-08-2015 Feb-14-2020 $ 50,000 $ (219 ) 2.5300 % One-month L Mar-31-2022
Schedule of the location in the financial statements of the gain or loss recognized on interest rate swaps	The table below details the location in the financial statements of the gain or loss recognized on interest rate swaps designated as cash flow hedges for the three months ended March 31, 2017 and March 31, 2016 (in thousands). Three months ended March 31, 2017 2016 Amount of income (loss) recognized in accumulated other comprehensive loss on interest rate swaps (effective portion) $ 514 $ (12,568 ) Amount of loss reclassified from accumulated other comprehensive loss into income (loss) as interest expense (effective portion) $ 698 $ 745 Amount of gain recognized in interest expense (ineffective portion) $ 156 $ —
Schedule of financial instruments accounted for at fair value on a recurring basis	The following sets forth the Company’s financial instruments that are accounted for at fair value on a recurring basis as of March 31, 2017 and December 31, 2016 . Fair Value Measurements as of Balance Sheet Line Item (in thousands) Fair Value Level 1 Level 2 Level 3 Interest rate swaps-Asset $ 2,378 $ — $ 2,378 $ — Interest rate swaps-Liability $ (1,985 ) $ — $ (1,985 ) $ — Fair Value Measurements as of Balance Sheet Line Item (in thousands) Fair Value December 31, 2016 Level 1 Level 2 Level 3 Interest rate swaps-Asset $ 1,471 $ — $ 1,471 $ — Interest rate swaps-Liability $ (2,438 ) $ — $ (2,438 ) $ —

Equity (Tables)

Equity (Tables)	3 Months Ended
	Mar. 31, 2017
Stockholders' Equity Note [Abstract]
Schedule of Stock by Class	Preferred Stock Issuances Issuance Date Number of Shares Liquidation Value Per Share Interest Rate 6.625% Series B Cumulative Redeemable Preferred Stock ("Series B Preferred Stock") April 16, 2013 2,800,000 $ 25.00 6.625 % 6.875% Series C Cumulative Redeemable Preferred Stock ("Series C Preferred Stock") March 17, 2016 3,000,000 $ 25.00 6.875 %
Schedule of dividends	Dividends The table below sets forth the dividends attributable to the common stock that were declared or paid during the three months ended March 31, 2017 and the year ended December 31, 2016 . Month Ended 2017 Declaration Date Record Date Per Share Payment Date June 30 February 15, 2017 June 30, 2017 $ 0.116667 July 17, 2017 May 31 February 15, 2017 May 31, 2017 0.116667 June 15, 2017 April 30 February 15, 2017 April 28, 2017 0.116667 May 15, 2017 March 31 November 2, 2016 March 31, 2017 0.116667 April 17, 2017 February 28 November 2, 2016 February 28, 2017 0.116667 March 15, 2017 January 31 November 2, 2016 January 31, 2017 0.116667 February 15, 2017 Total $ 0.700002 Month Ended 2016 Declaration Date Record Date Per Share Payment Date December 31 August 1, 2016 December 30, 2016 $ 0.115833 January 17, 2017 November 30 August 1, 2016 November 30, 2016 0.115833 December 15, 2016 October 31 August 1, 2016 October 31, 2016 0.115833 November 15, 2016 September 30 May 2, 2016 September 30, 2016 0.115833 October 17, 2016 August 31 May 2, 2016 August 31, 2016 0.115833 September 15, 2016 July 31 May 2, 2016 July 29, 2016 0.115833 August 15, 2016 June 30 February 22, 2016 June 30, 2016 0.115833 July 15, 2016 May 31 February 22, 2016 May 31, 2016 0.115833 June 15, 2016 April 30 February 22, 2016 April 29, 2016 0.115833 May 16, 2016 March 31 October 22, 2015 March 31, 2016 0.115833 April 15, 2016 February 29 October 22, 2015 February 29, 2016 0.115833 March 15, 2016 January 31 October 22, 2015 January 29, 2016 0.115833 February 16, 2016 Total $ 1.389996 The tables below set forth the dividends attributable to the Company's outstanding preferred stock issuances during the three months ended March 31, 2017 and the year ended December 31, 2016 . Quarter Ended 2017 Declaration Date Series B Series C Payment Date March 31 February 15, 2017 $ 0.4140625 $ 0.4296875 March 31, 2017 Total $ 0.4140625 $ 0.4296875 Quarter Ended 2016 Declaration Date Series A Preferred Stock Per Share Series B Preferred Stock Per Share Series C Preferred Stock Per Share Payment Date December 31 November 2, 2016 (1) $ 0.19375 (1) $ 0.4140625 $ 0.4296875 December 30, 2016 September 30 August 1, 2016 0.56250 0.4140625 0.4296875 September 30, 2016 June 30 May 2, 2016 0.56250 0.4140625 0.4965300 (2) June 30, 2016 March 31 February 22, 2016 0.56250 0.4140625 — March 31, 2016 Total $ 1.88125 $ 1.6562500 $ 1.3559050
Schedule of stock sale activity	The following sets forth the Company’s at-the market ("ATM") common stock offering program as of March 31, 2017 . ATM Stock Offering Program Date Maximum Aggregate Offering Price (in thousands) Aggregate Common Stock Available as of 2016 $228 million ATM November 8, 2016 $ 228,218 $ 48,788 The table below sets forth the activity for the ATM common stock offering programs during the three months ended March 31, 2017 and the year ended December 31, 2016 , respectively (in thousands, except share data). Three months ended March 31, 2017 ATM Stock Offering Program Shares Weighted Average Price Per Share Gross Sales Net 2016 $228 million ATM 2,843,907 $ 24.10 $ 68,543 $ 941 $ 67,602 Total/weighted average 2,843,907 $ 24.10 $ 68,543 $ 941 $ 67,602 Year ended December 31, 2016 ATM Stock Offering Program Shares Weighted Average Price Per Share Gross Sales Net 2016 $228 million ATM 4,763,838 $ 23.28 $ 110,887 $ 1,550 $ 109,337 2016 $200 million ATM (1) 7,326,200 $ 23.45 171,782 2,429 169,353 Total/weighted average 12,090,038 $ 23.38 $ 282,669 $ 3,979 $ 278,690 (1) This program ended before March 31, 2017 .
Schedule of activity related to unvested restricted stock awards	The following table summarizes activity related to the Company’s unvested restricted shares of common stock for the three months ended March 31, 2017 and the year ended December 31, 2016 . Unvested Restricted Shares of Common Stock Shares Balance at December 31, 2015 271,115 Granted 101,289 (1) Vested (98,746 ) Forfeited (1,321 ) Balance at December 31, 2016 272,337 Granted 75,001 (2) Vested (109,209 ) Forfeited (453 ) Balance at March 31, 2017 237,676 (1) The grant date fair value per share was $17.98 . (2) The grant date fair value per share was $24.41 .
Schedule of fair value at vesting date for awards vesting during the period	The following table summarizes the fair value at vesting for the restricted shares of common stock vested during the three months ended March 31, 2017 and March 31, 2016 . Three months ended March 31, 2017 2016 Vested restricted shares of common stock 109,209 84,336 Fair value of vested restricted shares of common stock (in thousands) $ 2,615 $ 1,522 The table below sets forth the assumptions used in valuing such LTIP units granted during the three months ended March 31, 2017 . LTIP Units Assumptions Grant date January 6, 2017 Expected term (years) 10 Expected volatility 23.0 % Expected dividend yield 6.0 % Risk-free interest rate 1.61 % Fair value of LTIP units at issuance (in thousands) $ 2,924 LTIP units at issuance 126,239 Fair value unit price per LTIP unit at issuance $ 23.16 The table below sets forth the assumptions used in valuing the performance units granted during the three months ended March 31, 2017 . Performance Units Assumptions Grant date January 6, 2017 Expected volatility 23.0 % Expected dividend yield 6.0 % Risk-free interest rate 1.61 % Fair value of performance units grant (in thousands) $ 2,882

Noncontrolling Interest (Tables

Noncontrolling Interest (Tables)	3 Months Ended
	Mar. 31, 2017
Noncontrolling Interest [Abstract]
Noncontrolling interest activity	The table below summarizes the activity for noncontrolling interest in the Company for the three months ended March 31, 2017 and the year ended December 31, 2016 . LTIP Units Other Common Units Total Noncontrolling Common Units Noncontrolling Interest Balance at December 31, 2015 1,610,105 1,915,872 3,525,977 4.9 % Granted/Issued 176,396 — 176,396 N/A Forfeited — — — N/A Conversions from LTIP units to Other Common Units (209,985 ) 209,985 — N/A Redemptions from Other Common Units to common stock — (68,492 ) (68,492 ) N/A Balance at December 31, 2016 1,576,516 2,057,365 3,633,881 4.3 % Granted/Issued 126,239 — 126,239 N/A Forfeited — — — N/A Conversions from LTIP units to Other Common Units (75,854 ) 75,854 — N/A Redemptions from Other Common Units to common stock — (145,029 ) (145,029 ) N/A Balance at March 31, 2017 1,626,901 1,988,190 3,615,091 4.2 %
Schedule of fair value at vesting date for awards vesting during the period	The following table summarizes the fair value at vesting for the restricted shares of common stock vested during the three months ended March 31, 2017 and March 31, 2016 . Three months ended March 31, 2017 2016 Vested restricted shares of common stock 109,209 84,336 Fair value of vested restricted shares of common stock (in thousands) $ 2,615 $ 1,522 The table below sets forth the assumptions used in valuing such LTIP units granted during the three months ended March 31, 2017 . LTIP Units Assumptions Grant date January 6, 2017 Expected term (years) 10 Expected volatility 23.0 % Expected dividend yield 6.0 % Risk-free interest rate 1.61 % Fair value of LTIP units at issuance (in thousands) $ 2,924 LTIP units at issuance 126,239 Fair value unit price per LTIP unit at issuance $ 23.16 The table below sets forth the assumptions used in valuing the performance units granted during the three months ended March 31, 2017 . Performance Units Assumptions Grant date January 6, 2017 Expected volatility 23.0 % Expected dividend yield 6.0 % Risk-free interest rate 1.61 % Fair value of performance units grant (in thousands) $ 2,882
Schedule of activity related to share-based compensation	The following table summarizes activity related to the Company’s unvested LTIP units for the three months ended March 31, 2017 and the year ended December 31, 2016 . Unvested LTIP Units LTIP Units Balance at December 31, 2015 534,910 Granted 176,396 Vested (307,883 ) Forfeited — Balance at December 31, 2016 403,423 Granted 126,239 Vested (67,670 ) Forfeited — Balance at March 31, 2017 461,992 The following table summarizes the fair value at vesting for the LTIP units vested during the three months ended March 31, 2017 and March 31, 2016 . Three months ended March 31, 2017 2016 Vested LTIP units 67,670 170,277 Fair value of vested LTIP units (in thousands) $ 1,664 $ 3,089

Equity Incentive Plan (Tables)

Equity Incentive Plan (Tables)	3 Months Ended
	Mar. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of fair value at vesting date for awards vesting during the period	The following table summarizes the fair value at vesting for the restricted shares of common stock vested during the three months ended March 31, 2017 and March 31, 2016 . Three months ended March 31, 2017 2016 Vested restricted shares of common stock 109,209 84,336 Fair value of vested restricted shares of common stock (in thousands) $ 2,615 $ 1,522 The table below sets forth the assumptions used in valuing such LTIP units granted during the three months ended March 31, 2017 . LTIP Units Assumptions Grant date January 6, 2017 Expected term (years) 10 Expected volatility 23.0 % Expected dividend yield 6.0 % Risk-free interest rate 1.61 % Fair value of LTIP units at issuance (in thousands) $ 2,924 LTIP units at issuance 126,239 Fair value unit price per LTIP unit at issuance $ 23.16 The table below sets forth the assumptions used in valuing the performance units granted during the three months ended March 31, 2017 . Performance Units Assumptions Grant date January 6, 2017 Expected volatility 23.0 % Expected dividend yield 6.0 % Risk-free interest rate 1.61 % Fair value of performance units grant (in thousands) $ 2,882
Summary of Equity Compensation Expense	The following table summarizes the amount recorded in general and administrative expenses in the accompanying Consolidated Statements of Operations for the amortization of restricted shares of common stock, LTIP units, Performance-based Compensation Plans, and the Company’s board of directors’ compensation for the three months ended March 31, 2017 and March 31, 2016 . Three months ended March 31, Non-Cash Compensation Expense (in thousands) 2017 2016 Restricted shares of common stock $ 592 $ 558 LTIP units 1,170 2,795 (1) Performance-based Compensation Plans 537 172 Board of directors compensation (2) 88 80 Total non-cash compensation expense $ 2,387 $ 3,605 (1) Inclusive of approximately $1.6 million of non-cash compensation expense during the three months ended March 31, 2016 associated with the severance cost of a former executive officer. (2) All of the Company’s independent directors elected to receive shares of common stock in lieu of cash for their service during the three months ended March 31, 2017 and March 31, 2016 . The number of shares of common stock granted is calculated based on the trailing 10 days average common stock price ending on the third business day preceding the grant date.

Earnings Per Share (Tables)

Earnings Per Share (Tables)	3 Months Ended
	Mar. 31, 2017
Earnings Per Share [Abstract]
Schedule of computation of basic and diluted earnings per common share	The following tables set forth the computation of basic and diluted earnings per common share for the three months ended March 31, 2017 and March 31, 2016 . Three months ended March 31, Earnings Per Share (in thousands, except share data) 2017 2016 Numerator Net income $ 69 $ 12,332 Less: preferred stock dividends 2,448 2,912 Less: amount allocated to participating securities 83 100 Less: income (loss) attributable to noncontrolling interest after preferred stock dividends (103 ) 482 Net income (loss) attributable to common stockholders $ (2,359 ) $ 8,838 Denominator Weighted average common shares outstanding — basic 81,807,883 67,889,217 Effect of dilutive securities (1) Unvested shares of restricted common stock — 43,529 Unvested Performance-based Compensation Plans — 31,813 Weighted average common shares outstanding — diluted 81,807,883 67,964,559 Net income (loss) per share — basic and diluted Net income (loss) per share attributable to common stockholders — basic $ (0.03 ) $ 0.13 Net income (loss) per share attributable to common stockholders — diluted $ (0.03 ) $ 0.13 (1) During the three months ended March 31, 2017 , there were 239,827 unvested shares of restricted common stock on a weighted average basis and 437,527 unvested performance units on a weighted average basis that were not included in the computation of diluted earnings per share because to do so would have been antidilutive for the period.

Organization and Description 28

Organization and Description of Business (Details) ft² in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2017ft²tenantstatebuilding	Dec. 31, 2016
Real Estate Properties [Line Items]
Ownership interest in Operating Partnership (as a percent)	95.80%	95.70%
Number of properties	324
Number of states in which the entity owned buildings | state	37
Area (in square feet) | ft²	63.2
Percentage of buildings leased to tenants	94.80%
Number of tenants | tenant	279
Warehouse - Distribution buildings
Real Estate Properties [Line Items]
Number of properties	254
Light Manufacturing buildings
Real Estate Properties [Line Items]
Number of properties	53
Flex/Office Buildings
Real Estate Properties [Line Items]
Number of properties	16
Other Property [Member]
Real Estate Properties [Line Items]
Number of properties	1

Summary of Significant Accoun29

Summary of Significant Accounting Policies Summary of Significant Accounting Polices - Effect of Revision (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016	Dec. 31, 2015
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	$ 1,103,970	$ 906,519	$ 1,066,926	$ 857,857
Depreciation and amortization	35,953	29,749
Costs and Expenses	59,264	54,235
Net income	69	12,332
Net Income (Loss) Attributable to Parent	172	11,850
Net income (loss) attributable to common stockholders	(2,359)	$ 8,838
Income (Loss) from Continuing Operations, Per Basic and Diluted Share		$ 0.13
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	$ 1,281	$ 509
Scenario, Adjustment [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest		3,009
Depreciation and amortization		(531)
Costs and Expenses		(531)
Net income		531
Net Income (Loss) Attributable to Parent		504
Net income (loss) attributable to common stockholders		$ 504
Income (Loss) from Continuing Operations, Per Basic and Diluted Share		$ 0.01
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest		$ 531
Scenario, Previously Reported [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest		903,510
Depreciation and amortization		30,280
Costs and Expenses		54,766
Net income		11,801
Net Income (Loss) Attributable to Parent		11,346
Net income (loss) attributable to common stockholders		$ 8,334
Income (Loss) from Continuing Operations, Per Basic and Diluted Share		$ 0.12
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest		$ (22)

Summary of Significant Accoun30

Summary of Significant Accounting Policies - Reclassifications and New Accounting Pronouncements (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net Cash Provided by (Used in) Operating Activities	$ 31,158	$ 25,217
Net cash provided by (used in) financing activities	64,678	(22,359)
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	1,281	509
Prepaid Expenses and Other Assets
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred financing fees, net	$ 2,100		$ 2,300
Adjustments for New Accounting Principle, Early Adoption [Member] | Accounting Standards Update 2016-15 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net Cash Provided by (Used in) Operating Activities		1,134
Net cash provided by (used in) financing activities		(1,130)
Scenario, Adjustment [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest		531
Scenario, Previously Reported [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest		$ (22)

Summary of Significant Accoun31

Summary of Significant Accounting Policies - Tenant Accounts Receivable (Details) - USD ($)	Mar. 31, 2017	Dec. 31, 2016
Tenant Accounts Receivable, net
Lease security deposits available in existing letters of credit	$ 10,900,000	$ 9,000,000
Cash and Cash Equivalents
Tenant Accounts Receivable, net
Security deposit	6,000,000	5,400,000
Restricted Cash
Tenant Accounts Receivable, net
Security deposit	400,000	400,000
Security Deposits
Tenant Accounts Receivable, net
Lease security deposits available in cash	6,400,000	5,800,000
Prepaid Expenses and Other Assets
Tenant Accounts Receivable, net
Due from related parties	31,000	48,000
Accrued Income Receivable [Member]
Tenant Accounts Receivable, net
Allowance for doubtful accounts	100,000	200,000
Accrued Rental Income
Tenant Accounts Receivable, net
Allowance for doubtful accounts	0	0
Accrued rental revenue	$ 19,900,000	$ 18,400,000

Summary of Significant Accoun32

Summary of Significant Accounting Policies - Revenue Recognition (Details) - USD ($)	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 27, 2017	Feb. 09, 2017
Revenue Recognition
Estimated amount of real estate taxes, which are the responsibility of tenants	$ 3,100,000	$ 2,600,000
Buena Vista, VA, Q3 2012 [Member]
Revenue Recognition
Lease termination fee receivable			$ 500,000
Buena Vista, VA, Q3 2012 [Member] | Rental income
Revenue Recognition
Gain (Loss) on Contract Termination	39,000
Belvidere, IL, Q2 2013, Six [Member]
Revenue Recognition
Lease termination fee receivable				$ 54,000
Belvidere, IL, Q2 2013, Six [Member] | Rental income
Revenue Recognition
Gain (Loss) on Contract Termination	54,000
Golden, CO, Q1 2013 [Member] | Rental income
Revenue Recognition
Gain (Loss) on Contract Termination	$ 200,000

Summary of Significant Accoun33

Summary of Significant Accounting Policies - Taxes (Details) - USD ($)	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Business Acquisition [Line Items]
Net income	$ 69,000	$ 12,332,000
State and local income, excise and franchise taxes	200,000	200,000
Liabilities for uncertain tax positions	0		$ 0
Real Estate Investment Trust
Business Acquisition [Line Items]
Net income	$ (31,000)	$ (11,000)

Rental Property - Summary (Deta

Rental Property - Summary (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Property Subject to or Available for Operating Lease [Line Items]
Rental property, net	$ 2,178,639	$ 2,116,836
Land
Property Subject to or Available for Operating Lease [Line Items]
Rental property, net	281,756	272,162
Building
Property Subject to or Available for Operating Lease [Line Items]
Rental property, net	1,468,933	1,408,406
Rental property, accumulated depreciation	134,236	125,971
Tenant improvements
Property Subject to or Available for Operating Lease [Line Items]
Rental property, net	24,846	24,974
Rental property, accumulated depreciation	29,748	28,388
Building and land improvements
Property Subject to or Available for Operating Lease [Line Items]
Rental property, net	110,937	107,463
Rental property, accumulated depreciation	38,111	33,054
Construction in progress
Property Subject to or Available for Operating Lease [Line Items]
Rental property, net	2,892	9,298
Deferred leasing intangibles
Property Subject to or Available for Operating Lease [Line Items]
Rental property, net	$ 289,275	294,533
Rental property, accumulated depreciation		$ 237,456

Rental Property - Acquisitions

Rental Property - Acquisitions (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2017USD ($)ft²building
Business Acquisition [Line Items]
Area (in square feet)	63,200,000
Acquisitions 2017 [Member]
Business Acquisition [Line Items]
Area (in square feet)	2,334,622
Number of Buildings Acquired | building	11
Business Combination, Consideration Transferred | $	$ 99,787
Jacksonville, FL, Q1 2017 [Member]
Business Acquisition [Line Items]
Area (in square feet)	1,025,720
Number of Buildings Acquired | building	4
Business Combination, Consideration Transferred | $	$ 34,264
Sparks, NV, Q1 2017 [Member]
Business Acquisition [Line Items]
Area (in square feet)	174,763
Number of Buildings Acquired | building	1
Business Combination, Consideration Transferred | $	$ 8,380
Salisbury, NC, Q1 2017 [Member]
Business Acquisition [Line Items]
Area (in square feet)	288,000
Number of Buildings Acquired | building	1
Business Combination, Consideration Transferred | $	$ 8,250
Franklin Township, NJ, Q1 2017 [Member]
Business Acquisition [Line Items]
Area (in square feet)	183,000
Number of Buildings Acquired | building	1
Business Combination, Consideration Transferred | $	$ 12,800
Milford, CT, Q1 2017 [Member]
Business Acquisition [Line Items]
Area (in square feet)	200,000
Number of Buildings Acquired | building	1
Business Combination, Consideration Transferred | $	$ 12,762
Bedford Heights, OH, Q1 2017 [Member]
Business Acquisition [Line Items]
Area (in square feet)	173,034
Number of Buildings Acquired | building	1
Business Combination, Consideration Transferred | $	$ 7,622
Redford, MI, Q1 2017 [Member]
Business Acquisition [Line Items]
Area (in square feet)	135,728
Number of Buildings Acquired | building	1
Business Combination, Consideration Transferred | $	$ 7,769
Burlington, NJ, Q1 2015 [Member]
Business Acquisition [Line Items]
Area (in square feet)	154,377
Number of Buildings Acquired | building	1
Business Combination, Consideration Transferred | $	$ 7,940

Rental Property - Acquisition36

Rental Property - Acquisitions - Allocation of Consideration (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2017USD ($)
In-place leases
Allocation of the consideration paid for the acquired assets and liabilities
Deferred leasing intangibles	$ 9,342
Acquisitions 2017 [Member]
Allocation of the consideration paid for the acquired assets and liabilities
Land	10,447
Buildings	66,647
Tenant improvements	1,720
Building and land Improvements	5,875
Below market leases	(469)
Total purchase price	$ 99,787
Weighted average amortization period of below market leases	7 years 5 months 18 days
Acquisitions 2017 [Member] | In-place leases
Allocation of the consideration paid for the acquired assets and liabilities
Weighted average amortization period of lease intangibles	5 years 4 months 18 days
Acquisitions 2017 [Member] | Tenant relationships
Allocation of the consideration paid for the acquired assets and liabilities
Deferred leasing intangibles	$ 4,383
Weighted average amortization period of lease intangibles	8 years 6 months 20 days
Acquisitions 2017 [Member] | Above market leases
Allocation of the consideration paid for the acquired assets and liabilities
Deferred leasing intangibles	$ 1,842
Weighted average amortization period of lease intangibles	4 years 8 months 31 days

Rental Property - Acquisition37

Rental Property - Acquisitions - Pro Forma (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Business Acquisition [Line Items]
Property acquisition costs	$ 740	$ 552
Acquisitions 2017 [Member]
Business Acquisition [Line Items]
Revenue	1,437
Property acquisition costs	593
Net income (loss)	669
Pro forma information
Total revenue	70,523	63,504
Net loss	1,093	12,216
Net loss attributable to common stockholders	(1,379)	8,727
Series of Individually Immaterial Business Acquisitions
Business Acquisition [Line Items]
Property acquisition costs	$ 593	$ 500

Rental Property - Disposals (De

Rental Property - Disposals (Details) ft² in Millions	3 Months Ended
	Mar. 31, 2017USD ($)ft²propertybuilding	Dec. 31, 2016USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Area (in square feet) | ft²	63.2
Carrying value of property sold	$ 2,178,639,000	$ 2,116,836,000
Disposal Group, Disposed of by Sale, Not Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Area (in square feet) | ft²	0.1
Number of buildings disposed | building	1
Carrying value of property sold	$ 3,600,000
Net proceeds from sales of rental property	3,919,000
Gain (Loss) on Sale	325,000
Contribution to revenue	15,000
Net income (loss) before gain on sale of rental property	$ 8,000
Disposal Group, Held-for-sale, Not Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of properties held-for-sale | property	2

Rental Property Rental Property

Rental Property Rental Property - Involuntary Conversion (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Loss Contingencies [Line Items]
Partial Disposal of Building Due to Involuntary Conversion	$ 221	$ 0
Storm Damage [Member]
Loss Contingencies [Line Items]
Partial Disposal of Building Due to Involuntary Conversion	600
Cumulative Partial Disposal of Building Due to Involuntary Conversion	1,300
Loss Contingency, Loss in Period	330
Insurance Settlements Receivable, Current	$ 800

Rental Property - Deferred Leas

Rental Property - Deferred Leasing Intangibles (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Above market lease, gross	$ 540,364		$ 531,989
Deferred leasing intangibles assets, accumulated amortization	(251,089)		(237,456)
Above market lease, net	289,275		294,533
Below market lease, gross	31,117		30,791
Below market lease, accumulated amortization	(11,443)		(10,450)
Below market lease, net	19,674		20,341
Net decrease to rental revenue related to above and below market lease amortization	1,296	$ 1,666
Below Market Lease, Net, Amortization Income, Fiscal Year Maturity [Abstract]
2,017	3,703
2,017	3,748
2,018	3,011
2,019	2,587
2,020	1,404
Above market leases
Finite-Lived Intangible Assets [Line Items]
Above market lease, gross	71,805		70,668
Deferred leasing intangibles assets, accumulated amortization	(34,594)		(32,868)
Above market lease, net	37,211		37,800
Other intangible lease assets
Finite-Lived Intangible Assets [Line Items]
Above market lease, gross	468,559		461,321
Deferred leasing intangibles assets, accumulated amortization	(216,495)		(204,588)
Above market lease, net	252,064		$ 256,733
Amortization expense related to other intangible lease assets	18,393	$ 15,913
Estimated Net Amortization of In-Place Leases, Leasing Commissions and Tenant Relationships
2,017	48,836
2,017	52,556
2,018	40,064
2,019	31,464
2,020	$ 22,206

Debt - Summary (Details)

Debt - Summary (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Principal outstanding	$ 1,067,251	$ 1,036,139
Weighted average interest rate	3.68%
Interest Rate Swaps
Debt Instrument [Line Items]
Notional amount	$ 450,000
One Month LIBOR
Debt Instrument [Line Items]
Variable rate basis reference rate (as a percent)	0.98278%
Secured Debt
Debt Instrument [Line Items]
Principal outstanding	$ 151,452	163,565
Long-term debt, gross	152,159	164,326
Unamortized debt issuance costs	(787)	(873)
Unamortized fair market value premium	80	112
Term Loan | Unsecured Debt
Debt Instrument [Line Items]
Principal outstanding	446,766	446,608
Long-term debt, gross	450,000	450,000
Unamortized debt issuance costs	(3,234)	(3,392)
$150 Million Wells Fargo Unsecured Term Loan C | Unsecured Debt
Debt Instrument [Line Items]
Long-term debt, gross	$ 150,000	150,000
$150 Million Wells Fargo Unsecured Term Loan C | Unsecured Debt | LIBOR
Debt Instrument [Line Items]
Interest rate margin (as a percent)	1.30%
$150 Million Wells Fargo Unsecured Term Loan B | Unsecured Debt
Debt Instrument [Line Items]
Long-term debt, gross	$ 150,000	150,000
$150 Million Wells Fargo Unsecured Term Loan B | Unsecured Debt | LIBOR
Debt Instrument [Line Items]
Interest rate margin (as a percent)	1.30%
$150 Million Wells Fargo Unsecured Term Loan A | Unsecured Debt
Debt Instrument [Line Items]
Long-term debt, gross	$ 150,000	150,000
$150 Million Wells Fargo Unsecured Term Loan A | Unsecured Debt | LIBOR
Debt Instrument [Line Items]
Interest rate margin (as a percent)	1.30%
Unsecured Notes | Unsecured Debt
Debt Instrument [Line Items]
Principal outstanding	$ 398,033	397,966
Long-term debt, gross	400,000	400,000
Unamortized debt issuance costs	(1,967)	(2,034)
$100 Million Series F Unsecured Notes | Unsecured Debt
Debt Instrument [Line Items]
Long-term debt, gross	$ 100,000	100,000
Stated interest rate	3.98%
$50 Million Series A Unsecured Notes | Unsecured Debt
Debt Instrument [Line Items]
Long-term debt, gross	$ 50,000	50,000
Stated interest rate	4.98%
$100 Million Series D Unsecured Notes | Unsecured Debt
Debt Instrument [Line Items]
Long-term debt, gross	$ 100,000	100,000
Stated interest rate	4.32%
$50 Million Series B Unsecured Notes | Unsecured Debt
Debt Instrument [Line Items]
Long-term debt, gross	$ 50,000	50,000
Stated interest rate	4.98%
$80 Million Series C Unsecured Notes | Unsecured Debt
Debt Instrument [Line Items]
Long-term debt, gross	$ 80,000	80,000
Stated interest rate	4.42%
$20 Million Series E Unsecured Notes | Unsecured Debt
Debt Instrument [Line Items]
Long-term debt, gross	$ 20,000	20,000
Stated interest rate	4.42%
Union Fidelity Life Insurance Co Due April 30, 2017 | Secured Debt
Debt Instrument [Line Items]
Long-term debt, gross	$ 0	5,384
Stated interest rate	5.81%
Penalty free prepayment period	2 months
Webster Bank, National Association due May 29, 2017 | Secured Debt
Debt Instrument [Line Items]
Long-term debt, gross	$ 0	2,853
Stated interest rate	3.66%
Webster Bank, National Association due May 31, 2017 | Secured Debt
Debt Instrument [Line Items]
Long-term debt, gross	$ 0	3,073
Stated interest rate	3.64%
Wells Fargo, National Association Due August 1, 2017 | Secured Debt
Debt Instrument [Line Items]
Long-term debt, gross	$ 4,024	4,043
Stated interest rate	5.90%
Penalty free prepayment period	3 months
Connecticut General Life Insurance Company - Facility 1 | Secured Debt
Debt Instrument [Line Items]
Long-term debt, gross	$ 35,167	35,320
Stated interest rate	6.50%
Connecticut General Life Insurance Company - Facility 2 | Secured Debt
Debt Instrument [Line Items]
Long-term debt, gross	$ 36,717	36,892
Stated interest rate	5.75%
Connecticut General Life Insurance Company - Facility 3 | Secured Debt
Debt Instrument [Line Items]
Long-term debt, gross	$ 16,073	16,141
Stated interest rate	5.88%
Wells Fargo Bank, National Association CMBS Loan | Secured Debt
Debt Instrument [Line Items]
Long-term debt, gross	$ 56,192	56,608
Stated interest rate	4.31%
Penalty free prepayment period	3 months
Thrivent Financial for Lutherans Due December 15, 2023 [Member] | Secured Debt
Debt Instrument [Line Items]
Long-term debt, gross	$ 3,986	4,012
Stated interest rate	4.78%
Connecticut General Life Insurance Company Facilities | Secured Debt
Debt Instrument [Line Items]
Penalty free prepayment period	6 months
Line of Credit | Unsecured Debt
Debt Instrument [Line Items]
Principal outstanding	$ 71,000	28,000
Line of Credit | $450 Million Wells Fargo Unsecured Credit Facility | Unsecured Debt
Debt Instrument [Line Items]
Principal outstanding	$ 71,000	28,000
Maximum borrowing capacity		$ 450,000
Line of Credit | $450 Million Wells Fargo Unsecured Credit Facility | Unsecured Debt | LIBOR
Debt Instrument [Line Items]
Interest rate margin (as a percent)	1.15%

Debt - 2017 Activity (Details)

Debt - 2017 Activity (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Debt Instrument [Line Items]
Unused borrowing capacity	$ 375,600
Amortization of deferred financing fees	526	$ 474
Net book value of properties that are collateral for debt arrangements	211,000		$ 229,900
Secured Debt
Debt Instrument [Line Items]
Deferred financing fees, net	$ 787		873
Webster Bank, National Association due May 31, 2017 [Member] | Secured Debt
Debt Instrument [Line Items]
Penalty free prepayment period	3 months
Thrivent Financial for Lutherans Due December 15, 2023 [Member] | Secured Debt
Debt Instrument [Line Items]
Stated interest rate	4.78%
Connecticut General Life Insurance Company - Facility 2 | Secured Debt
Debt Instrument [Line Items]
Stated interest rate	5.75%
Wells Fargo Bank, National Association CMBS Loan | Secured Debt
Debt Instrument [Line Items]
Penalty free prepayment period	3 months
Stated interest rate	4.31%
Prepaid Expenses and Other Assets
Debt Instrument [Line Items]
Deferred financing fees, net	$ 2,100		2,300
Accounts Payable, Accrued Expenses and Other Liabilities
Debt Instrument [Line Items]
Interest payable	5,300		$ 5,700
Interest Expense [Member] | Line of Credit | $450 Million Wells Fargo Unsecured Credit Facility | Unsecured Debt
Debt Instrument [Line Items]
Line of Credit Facility, Commitment Fee Amount	$ 238	$ 240

Debt - Fair Value (Details)

Debt - Fair Value (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Principal outstanding	$ 1,067,251	$ 1,036,139
Unsecured Debt | Term Loan
Debt Instrument [Line Items]
Long-term debt, gross	450,000	450,000
Unamortized debt issuance costs	(3,234)	(3,392)
Principal outstanding	446,766	446,608
Unsecured Debt | Unsecured Notes
Debt Instrument [Line Items]
Long-term debt, gross	400,000	400,000
Unamortized debt issuance costs	(1,967)	(2,034)
Principal outstanding	398,033	397,966
Unsecured Debt | Line of Credit
Debt Instrument [Line Items]
Principal outstanding	71,000	28,000
Secured Debt
Debt Instrument [Line Items]
Long-term debt, gross	152,159	164,326
Unamortized fair market value premium	80	112
Unamortized debt issuance costs	(787)	(873)
Principal outstanding	151,452	163,565
Reported Value Measurement [Member]
Debt Instrument [Line Items]
Long-term debt, gross	1,073,159	1,042,326
Unamortized fair market value premium	80	112
Unamortized debt issuance costs	(5,988)	(6,299)
Principal outstanding	1,067,251	1,036,139
Reported Value Measurement [Member] | Unsecured Debt | Term Loan
Debt Instrument [Line Items]
Long-term debt, gross	450,000	450,000
Reported Value Measurement [Member] | Unsecured Debt | Unsecured Notes
Debt Instrument [Line Items]
Long-term debt, gross	400,000	400,000
Reported Value Measurement [Member] | Unsecured Debt | Line of Credit
Debt Instrument [Line Items]
Long-term debt, gross	71,000	28,000
Reported Value Measurement [Member] | Secured Debt | Mortgages
Debt Instrument [Line Items]
Long-term debt, gross	152,159	164,326
Fair Value, Inputs, Level 3 | Fair Value
Debt Instrument [Line Items]
Long-term debt, fair value	1,089,061	1,043,190
Fair Value, Inputs, Level 3 | Fair Value | Unsecured Debt | Term Loan
Debt Instrument [Line Items]
Long-term debt, fair value	450,000	450,000
Fair Value, Inputs, Level 3 | Fair Value | Unsecured Debt | Unsecured Notes
Debt Instrument [Line Items]
Long-term debt, fair value	413,928	399,091
Fair Value, Inputs, Level 3 | Fair Value | Unsecured Debt | Line of Credit
Debt Instrument [Line Items]
Long-term debt, fair value	71,000	28,000
Fair Value, Inputs, Level 3 | Fair Value | Secured Debt | Mortgages
Debt Instrument [Line Items]
Long-term debt, fair value	$ 154,133	$ 166,099
Minimum | Fair Value, Inputs, Level 3 | Long-term Debt | Income Approach Valuation Technique
Debt Instrument [Line Items]
Fair Value Inputs, Discount Rate	2.13%	1.92%
Maximum | Fair Value, Inputs, Level 3 | Long-term Debt | Income Approach Valuation Technique
Debt Instrument [Line Items]
Fair Value Inputs, Discount Rate	4.54%	4.85%

Use of Derivative Financial I44

Use of Derivative Financial Instruments - Risk Management and Unsecured Loan Swaps (Details) $ in Thousands	Mar. 31, 2017USD ($)
Interest Rate Swaps
Unsecured Term Loan Swaps
Notional amount	$ 450,000
Interest Rate Derivative, PNC Bank, October 10, 2012
Unsecured Term Loan Swaps
Notional amount	10,000
Fair value	$ 12
Fixed Interest Rate (as a percent)	0.7945%
Interest Rate Derivative, Bank of America, October 10, 2012
Unsecured Term Loan Swaps
Notional amount	$ 10,000
Fair value	$ 12
Fixed Interest Rate (as a percent)	0.7945%
Interest Rate Derivative, UBS AG, October 10, 2012
Unsecured Term Loan Swaps
Notional amount	$ 10,000
Fair value	$ 12
Fixed Interest Rate (as a percent)	0.7945%
Interest Rate Derivative, Royal Bank of Canada, October 10, 2012
Unsecured Term Loan Swaps
Notional amount	$ 10,000
Fair value	$ 12
Fixed Interest Rate (as a percent)	0.7945%
Interest Rate Derivative, RJ Capital Services, Inc, October 10, 2012, One
Unsecured Term Loan Swaps
Notional amount	$ 10,000
Fair value	$ 12
Fixed Interest Rate (as a percent)	0.7975%
Interest Rate Derivative, Bank of America, October 10, 2012, Two
Unsecured Term Loan Swaps
Notional amount	$ 25,000
Fair value	$ 36
Fixed Interest Rate (as a percent)	0.7525%
Interest Rate Derivative, RJ Capital Services, October 10, 2012, Two
Unsecured Term Loan Swaps
Notional amount	$ 25,000
Fair value	$ 39
Fixed Interest Rate (as a percent)	0.727%
Interest Rate Derivative, Regions Bank, March 01, 2013
Unsecured Term Loan Swaps
Notional amount	$ 25,000
Fair value	$ 216
Fixed Interest Rate (as a percent)	1.33%
Interest Rate Derivative, Capital One, June 01, 2013
Unsecured Term Loan Swaps
Notional amount	$ 50,000
Fair value	$ (66)
Fixed Interest Rate (as a percent)	1.681%
Interest Rate Derivative, Capital One, August 01, 2013
Unsecured Term Loan Swaps
Notional amount	$ 25,000
Fair value	$ (49)
Fixed Interest Rate (as a percent)	1.703%
Interest Rate Derivative, Regions Bank, February 03, 2014
Unsecured Term Loan Swaps
Notional amount	$ 25,000
Fair value	$ (254)
Fixed Interest Rate (as a percent)	1.9925%
Interest Rate Derivative, The Toronto-Dominion Bank, September 29, 2016
Unsecured Term Loan Swaps
Notional amount	$ 25,000
Fair value	$ 299
Fixed Interest Rate (as a percent)	1.383%
Interest Rate Derivative, PNC Bank, September 29, 2016
Unsecured Term Loan Swaps
Notional amount	$ 50,000
Fair value	$ 588
Fixed Interest Rate (as a percent)	1.3906%
Interest Rate Derivative, Regions Bank, September 29, 2016
Unsecured Term Loan Swaps
Notional amount	$ 35,000
Fair value	$ 414
Fixed Interest Rate (as a percent)	1.3858%
Interest Rate Derivative, US Bank, September 29, 2016
Unsecured Term Loan Swaps
Notional amount	$ 25,000
Fair value	$ 290
Fixed Interest Rate (as a percent)	1.395%
Interest Rate Derivative, Capital One, September 29, 2016
Unsecured Term Loan Swaps
Notional amount	$ 15,000
Fair value	$ 173
Fixed Interest Rate (as a percent)	1.395%
Interest Rate Derivative, Royal Bank of Canada, March 20, 2015
Unsecured Term Loan Swaps
Notional amount	$ 25,000
Fair value	$ 81
Fixed Interest Rate (as a percent)	1.709%
Interest Rate Derivative, The Toronto-Dominion Bank, March 20, 2015
Unsecured Term Loan Swaps
Notional amount	$ 25,000
Fair value	$ 80
Fixed Interest Rate (as a percent)	1.7105%
Interest Rate Derivative, The Toronto-Dominion Bank, September 10, 2017
Unsecured Term Loan Swaps
Notional amount	$ 100,000
Fair value	$ (1,159)
Fixed Interest Rate (as a percent)	2.2255%
Interest Rate Derivative, Wells Fargo Bank, March 20, 2015
Unsecured Term Loan Swaps
Notional amount	$ 25,000
Fair value	$ 102
Fixed Interest Rate (as a percent)	1.828%
Interest Rate Derivative, The Toronto-Dominion Bank, February 14, 2020
Unsecured Term Loan Swaps
Notional amount	$ 25,000
Fair value	$ (71)
Fixed Interest Rate (as a percent)	2.4535%
Interest Rate Derivative, Regions Bank, February 14, 2020
Unsecured Term Loan Swaps
Notional amount	$ 50,000
Fair value	$ (167)
Fixed Interest Rate (as a percent)	2.475%
Interest Rate Derivative, Capital One, February 14, 2020
Unsecured Term Loan Swaps
Notional amount	$ 50,000
Fair value	$ (219)
Fixed Interest Rate (as a percent)	2.53%

Use of Derivative Financial I45

Use of Derivative Financial Instruments - FV of Interest Rate Swaps (Details) - Interest Rate Swaps - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Fair value of the interest rate swaps outstanding
Notional amount assets	$ 350,000	$ 300,000
Fair value - assets	2,378	1,471
Notional amount liabilities	325,000	375,000
Fair Value - liabilities	$ (1,985)	$ (2,438)

Use of Derivative Financial I46

Use of Derivative Financial Instruments - Cash Flow Hedges and Contingent Features (Details) - Interest Rate Swaps - USD ($)	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Risk Management Objective of Using Derivatives
Gain (Loss) on Cash Flow Hedge Ineffectiveness, Net	$ 156,000	$ 0
Cash Flow Hedges of Interest Rate Risk
Additional amount reclassified from accumulated other comprehensive income (loss) as an increase to interest expense over the next twelve months	1,300,000
Amount of income (loss) recognized in accumulated other comprehensive income (loss) on interest rate swaps (effective portion)	514,000	(12,568,000)
Amount of loss reclassified from accumulated other comprehensive income (loss) into income (loss) as interest expense (effective portion)	698,000	745,000
Amount of gain (loss) recognized in interest expense (ineffective portion and amount excluded from effectiveness testing)	(156,000)	$ 0
Credit-risk-related Contingent Features
Termination value required to settle obligations under agreements	$ 1,100,000

Use of Derivative Financial I47

Use of Derivative Financial Instruments - FV on Recurring Basis (Details) - Interest Rate Swaps - Fair value on recurring basis - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Assets (liabilities):
Interest rate swaps-Asset	$ 2,378	$ 1,471
Interest rate swaps-Liability	(1,985)	(2,438)
Level 1
Assets (liabilities):
Interest rate swaps-Asset	0	0
Interest rate swaps-Liability	0	0
Level 2
Assets (liabilities):
Interest rate swaps-Asset	2,378	1,471
Interest rate swaps-Liability	(1,985)	(2,438)
Level 3
Assets (liabilities):
Interest rate swaps-Asset	0	0
Interest rate swaps-Liability	$ 0	$ 0

Equity - Preferred Stock (Detai

Equity - Preferred Stock (Details) - $ / shares	May 01, 2017	Mar. 31, 2017	Feb. 15, 2017	Dec. 30, 2016	Nov. 02, 2016	Sep. 30, 2016	Aug. 01, 2016	Jun. 30, 2016	May 02, 2016	Mar. 31, 2016	Feb. 22, 2016	Mar. 31, 2017	Dec. 31, 2016
Class of Stock [Line Items]
Preferred stock, shares authorized		15,000,000										15,000,000	15,000,000
Preferred stock, par value (in dollars per share)		$ 0.01										$ 0.01	$ 0.01
Series B Preferred Stock
Class of Stock [Line Items]
Preferred Stock, Dividends Per Share, Declared			$ 0.4140625		$ 0.4140625		$ 0.4140625		$ 0.4140625		$ 0.4140625	0.4140625	1.65625
Preferred Stock, Dividends, Per Share, Cash Paid		0.4140625		$ 0.4140625		$ 0.4140625		$ 0.4140625		$ 0.4140625		$ 0.4140625	1.65625
Number of shares sold												2,800,000
Issue price (in dollars per share)		25										$ 25
Dividend rate (as a percent)												6.625%
Series B Preferred Stock | Non-recognized Subsequent Event
Class of Stock [Line Items]
Preferred Stock, Dividends Per Share, Declared	$ 0.4140625
Series C Preferred Stock
Class of Stock [Line Items]
Preferred Stock, Dividends Per Share, Declared			$ 0.4296875		0.4296875		0.4296875		0.4965300		0	$ 0.4296875	1.355905
Preferred Stock, Dividends, Per Share, Cash Paid		0.4296875		0.4296875		0.4296875		0.49653				$ 0.4296875	1.355905
Number of shares sold												3,000,000
Issue price (in dollars per share)		$ 25										$ 25
Dividend rate (as a percent)												6.875%
Series C Preferred Stock | Non-recognized Subsequent Event
Class of Stock [Line Items]
Preferred Stock, Dividends Per Share, Declared	$ 0.4296875
Series A Preferred Stock
Class of Stock [Line Items]
Preferred Stock, Dividends Per Share, Declared					0.19375		$ 0.56250		$ 0.56250		$ 0.56250		1.88125
Preferred Stock, Dividends, Per Share, Cash Paid				$ 0.19375		$ 0.5625		$ 0.5625		$ 0.5625			$ 1.88125
Preferred Stock, Redemption Price Per Share					$ 25

Equity - Common Stock (Details)

Equity - Common Stock (Details) - USD ($)	Jul. 17, 2017	Jun. 15, 2017	May 15, 2017	May 01, 2017	Apr. 17, 2017	Apr. 07, 2017	Mar. 15, 2017	Feb. 15, 2017	Jan. 16, 2017	Dec. 15, 2016	Nov. 15, 2016	Nov. 02, 2016	Oct. 15, 2016	Sep. 15, 2016	Aug. 15, 2016	Aug. 01, 2016	Jul. 15, 2016	Jun. 15, 2016	May 16, 2016	May 02, 2016	Apr. 15, 2016	Mar. 15, 2016	Feb. 22, 2016	Feb. 16, 2016	Oct. 22, 2015	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Class of Stock [Line Items]
Proceeds from sales of common stock																										$ 68,543,000	$ 0
Common Stock
Class of Stock [Line Items]
Dividend declared (in dollars per share)								$ 0.116667				$ 0.116667				$ 0.115833				$ 0.115833			$ 0.115833		$ 0.115833	$ 0.700002		$ 1.389996
Dividends paid (in dollars per share)							$ 0.116667	$ 0.116667	$ 0.115833	$ 0.115833	$ 0.115833		$ 0.115833	$ 0.115833	$ 0.115833		$ 0.115833	$ 0.115833	$ 0.115833		$ 0.115833	$ 0.115833		$ 0.115833		$ 0.700002		$ 1.389996
Common Stock | Scenario, Forecast
Class of Stock [Line Items]
Dividends paid (in dollars per share)	$ 0.116667	$ 0.116667	$ 0.116667		$ 0.116667
Common Stock | Non-recognized Subsequent Event
Class of Stock [Line Items]
Dividend declared (in dollars per share)				$ 0.1175
At The Market Program 2016 $200 Million [Member] | Common Stock
Class of Stock [Line Items]
Common Stock Value Authorized under Stock Offering Program																												$ 200,000,000
At The Market Program 2017 $300 Million [Domain] | Non-recognized Subsequent Event
Class of Stock [Line Items]
Number of shares sold						5,344,543
Proceeds from sales of common stock						$ 135,000,000
Net proceeds						133,400,000
At The Market Program 2017 $300 Million [Domain] | Common Stock | Non-recognized Subsequent Event
Class of Stock [Line Items]
Common Stock Value Authorized under Stock Offering Program						$ 300,000,000
At The Market Program 2016 $200 Million [Member] | Common Stock
Class of Stock [Line Items]
Common Stock Value Authorized under Stock Offering Program																										$ 228,218,000
Aggregate value of common stock available to be sold under the ATM																										$ 48,788,000
Number of shares sold																										2,843,907		4,763,838
Proceeds from sales of common stock																										$ 68,543,000		$ 110,887,000
Sales agents' fee																										941,000		1,550,000
Net proceeds																										$ 67,602,000		$ 109,337,000
2014 $200 Million ATM | Common Stock
Class of Stock [Line Items]
Number of shares sold																												7,326,200
Proceeds from sales of common stock																												$ 171,782,000
Sales agents' fee																												2,429,000
Net proceeds																												$ 169,353,000
At The Market (ATM) Program | Common Stock
Class of Stock [Line Items]
Number of shares sold																										2,843,907		12,090,038
Proceeds from sales of common stock																										$ 68,543,000		$ 282,669,000
Sales agents' fee																										941,000		3,979,000
Net proceeds																										$ 67,602,000		$ 278,690,000
Weighted Average | At The Market Program 2016 $200 Million [Member] | Common Stock
Class of Stock [Line Items]
Issue price (in dollars per share)																										$ 24.10		$ 23.28
Weighted Average | 2014 $200 Million ATM | Common Stock
Class of Stock [Line Items]
Issue price (in dollars per share)																												23.45
Weighted Average | At The Market (ATM) Program | Common Stock
Class of Stock [Line Items]
Issue price (in dollars per share)																										$ 24.10		$ 23.38

Equity - Restricted Stock (Deta

Equity - Restricted Stock (Details) - Restricted stock - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Shares
Unvested at end of period (in shares)	239,827	285,458
2011 Equity Incentive Plan
Shares
Unvested at beginning of period (in shares)	272,337	271,115	271,115
Granted (in shares)	75,001		101,289
Vested (in shares)	(109,209)	(84,336)	(98,746)
Forfeited (in shares)	(453)		(1,321)
Unvested at end of period (in shares)	237,676		272,337
Grant date fair value (in dollars per share)	$ 24.41		$ 17.98
Unrecognized compensation costs	$ 4,500
Number of shares vested	109,209	84,336	98,746
Fair value of shares vested	$ 2,615	$ 1,522
Unrecognized compensation costs, period for recognition	2 years 7 months 29 days
Granted on January 8, 2016 | 2011 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)	4 years

Noncontrolling Interest (Detail

Noncontrolling Interest (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016	Dec. 31, 2015
Noncontrolling interest
Noncontrolling interest ownership percentage	4.20%		4.30%	4.90%
LTIP Units | 2011 Equity Incentive Plan
Summary of nonvested share-based compensation activity
Unvested at beginning of period (in shares)	403,423	534,910	534,910
Granted (in shares)	126,239		176,396
Vested (in shares)	(67,670)	(170,277)	(307,883)
Forfeited (in shares)	0		0
Unvested at end of period (in shares)	461,992		403,423
Fair value of shares vested	$ 1,664	$ 3,089
Noncontrolling Interest - Unit holders in Operating Partnership
Noncontrolling interest
Units outstanding, balance at beginning of period (in units)	3,633,881	3,525,977	3,525,977
Granted/Issued (in units)	126,239		176,396
Forfeitures (in units)	0		0
Limited Partners' Capital Account, Units, Converted	0		0
Redemptions from Other Common Units to common stock (in units)	(145,029)		(68,492)
Units outstanding, balance at end of period (in units)	3,615,091		3,633,881
LTIP Units | Noncontrolling Interest - Unit holders in Operating Partnership
Noncontrolling interest
Units outstanding, balance at beginning of period (in units)	1,576,516	1,610,105	1,610,105
Granted/Issued (in units)	126,239		176,396
Forfeitures (in units)	0		0
Limited Partners' Capital Account, Units, Converted	75,854		209,985
Redemptions from Other Common Units to common stock (in units)	0		0
Units outstanding, balance at end of period (in units)	1,626,901		1,576,516
Other Common Units | Noncontrolling Interest - Unit holders in Operating Partnership
Noncontrolling interest
Units outstanding, balance at beginning of period (in units)	2,057,365	1,915,872	1,915,872
Granted/Issued (in units)	0		0
Forfeitures (in units)	0		0
Limited Partners' Capital Account, Units, Converted	(75,854)		(209,985)
Redemptions from Other Common Units to common stock (in units)	(145,029)		(68,492)
Units outstanding, balance at end of period (in units)	1,988,190		2,057,365

Noncontrolling Interest - LTIP

Noncontrolling Interest - LTIP Units Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
General and Administrative Expenses
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation	$ 2,387	$ 3,605
LTIP Units | General and Administrative Expenses
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation	1,170	2,795
2011 Equity Incentive Plan | LTIP Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation costs	$ 8,300
Unrecognized compensation costs, period for recognition	2 years 7 months 29 days
2011 Equity Incentive Plan | LTIP Units | Geoffrey G. Jervis | General and Administrative Expenses
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation		$ 1,600
Grant Date January 8, 2016 | Awards vest over five years | 2011 Equity Incentive Plan | LTIP Units | Executive officers
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)	4 years

Noncontrolling Interest - FV As

Noncontrolling Interest - FV Assumptions (Details) - LTIP Units - 2011 Equity Incentive Plan - USD ($) $ / shares in Units, $ in Thousands	Jan. 06, 2017	Mar. 31, 2017	Dec. 31, 2016
Assumptions
Units at issuance (in shares)		126,239	176,396
Grant Date February 22, 2016
Assumptions
Expected term	10 years
Expected volatility (as a percent)	23.00%
Expected dividend yield (as a percent)	6.00%
Risk-free interest rate (as a percent)	1.61%
Fair value of units at issuance	$ 2,924
Units at issuance (in shares)	126,239
Fair value share price per unit (in dollars per share)	$ 23.16

Equity Incentive Plan - Summary

Equity Incentive Plan - Summary (Details) - 2011 Equity Incentive Plan - Performance shares $ in Thousands	Jan. 06, 2017USD ($)benchmark	Mar. 31, 2017USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation costs		$ 4,700
Unrecognized compensation costs, period for recognition		2 years 7 months 29 days
Awarded in 2017 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Measurement period for outperformance pool plan threshold	3 years
Allocation for Company TSR compared to industry peer group	25.00%
Allocation for Company TSR compared to size-based peer group	25.00%
Allocation for Company TSR compared to MSCI US REIT index	50.00%
Value of awards	$ 2,882
Awarded in 2017 [Member] | Vest immediately after measurement period
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting rights, percent	50.00%
Awarded in 2017 [Member] | Vest one year after measurement period
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting rights, percent	50.00%
Vesting period (in years)	1 year
Awarded in 2017 [Member] | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percent of target units awarded	0.00%
Awarded in 2017 [Member] | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percent of target units awarded	250.00%
Awarded in 2017 [Member] | Weighted Average
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility (as a percent)	23.00%
Risk-free interest rate (as a percent)	1.61%
Expected dividend yield (as a percent)	6.00%
Awarded in 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of benchmarks | benchmark	3

Equity Incentive Plan Equity In

Equity Incentive Plan Equity Incentive Plan - Performance Plan Assumptions (Details) - Performance Shares [Member] - 2011 Equity Incentive Plan - Awarded in 2017 [Member] $ in Thousands	Jan. 06, 2017USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Value of awards	$ 2,882
Weighted Average
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate	23.00%
Expected dividend yield (as a percent)	6.00%
Risk-free interest rate (as a percent)	1.61%

Equity Incentive Plan - Equity

Equity Incentive Plan - Equity Non-cash Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
2011 Equity Incentive Plan | Common Stock
Equity Incentive Plan
Number of days of average trailing stock price used to calculate number of shares of common stock granted	10 days
General and Administrative Expenses
Equity Incentive Plan
Share-based compensation	$ 2,387	$ 3,605
General and Administrative Expenses | Independent Director
Equity Incentive Plan
Share-based compensation	88	80
General and Administrative Expenses | Restricted stock
Equity Incentive Plan
Share-based compensation	592	558
General and Administrative Expenses | LTIP Units
Equity Incentive Plan
Share-based compensation	1,170	2,795
General and Administrative Expenses | LTIP Units | Geoffrey G. Jervis | 2011 Equity Incentive Plan
Equity Incentive Plan
Share-based compensation		1,600
General and Administrative Expenses | Performance shares
Equity Incentive Plan
Share-based compensation	$ 537	$ 172

Earnings Per Share (Details)

Earnings Per Share (Details) - shares	Mar. 31, 2017	Mar. 31, 2016
Restricted stock
Antidilutive participating securities
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number	239,827	285,458

Earnings Per Share - Reconcilia

Earnings Per Share - Reconciliation of Numerator and Denominator (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Numerator
Net income (loss) from continuing operations	$ 69	$ 12,332
Less: preferred stock dividends	2,448	2,912
Less: amount allocated to participating securities	83	100
Less: loss attributable to noncontrolling interest after preferred stock dividends	(103)	482
Net income (loss) attributable to common stockholders	$ (2,359)	$ 8,838
Denominator
Weighted Average Number of Shares Outstanding, Basic	81,807,883	67,889,217
Weighted average common shares outstanding — diluted (in shares)	81,807,883	67,964,559
Net income (loss) per share — basic and diluted
Income (Loss) from Continuing Operations, Per Basic Share	$ (0.03)	$ 0.13
Income (loss) from continuing operations attributable to common stockholders - diluted (in dollars per share)	$ (0.03)	$ 0.13
Restricted stock
Denominator
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements	0	43,529
Net income (loss) per share — basic and diluted
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	239,827
Performance Shares [Member]
Denominator
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements	0	31,813
Net income (loss) per share — basic and diluted
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	437,527

Commitments and Contingencies -

Commitments and Contingencies - Agreements (Details) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2017	Dec. 31, 2016
Business Acquisition, Contingent Consideration [Line Items]
Letters of credit outstanding	$ 3,400,000
Property Acquisition under Agreement with Columbus Nova | Incentive Fee
Business Acquisition, Contingent Consideration [Line Items]
Fair value of incentive fee	$ 0	$ 0
Minimum | Property Acquisition under Agreement with Columbus Nova | Incentive Fee | Fair Value, Inputs, Level 3 | Market And Income Approach Valuation Technique | Contingent Consideration
Business Acquisition, Contingent Consideration [Line Items]
Fair Value Inputs, Discount Rate	8.50%	8.00%
Fair Value Inputs Exit Capitalization Rate	7.50%	7.00%
Maximum | Property Acquisition under Agreement with Columbus Nova | Incentive Fee | Fair Value, Inputs, Level 3 | Market And Income Approach Valuation Technique | Contingent Consideration
Business Acquisition, Contingent Consideration [Line Items]
Fair Value Inputs, Discount Rate	12.00%	12.00%
Fair Value Inputs Exit Capitalization Rate	12.00%	12.00%

Subsequent Events Subsequent Ev

Subsequent Events Subsequent Events - Acquisitions (Details) ft² in Millions, $ in Millions	1 Months Ended
	May 02, 2017USD ($)ft²building	Mar. 31, 2017ft²
Subsequent Event [Line Items]
Area (in square feet)		63.2
Non-recognized Subsequent Event
Subsequent Event [Line Items]
Number of Buildings Acquired | building	3
Area (in square feet)	0.5
Business Combination, Consideration Transferred | $	$ 20.6