STAG INDUSTRIAL, INC., 10-Q filed on 5/1/2018
Quarterly Report
v3.8.0.1
Document and Entity Information - shares
 3 Months Ended
Mar. 31, 2018
Apr. 30, 2018
Document and Entity Information    
Entity Registrant Name STAG Industrial, Inc.  
Entity Central Index Key 0001479094  
Document Type 10-Q  
Document Period End Date Mar. 31, 2018  
Amendment Flag false  
Current Fiscal Year End Date --12-31  
Entity Filer Category Large Accelerated Filer  
Entity Common Stock, Shares Outstanding   97,233,361
Document Fiscal Year Focus 2018  
Document Fiscal Period Focus Q1  
v3.8.0.1
Consolidated Balance Sheets - USD ($)
$ in Thousands
Mar. 31, 2018
Dec. 31, 2017
Rental Property:    
Land $ 324,734 $ 321,560
Buildings and improvements, net of accumulated depreciation of $266,158 and $249,057, respectively 1,958,432 1,932,764
Deferred leasing intangibles, net of accumulated amortization of $215,597 and $280,642, respectively 305,188 313,253
Total rental property, net 2,588,354 2,567,577
Cash and cash equivalents 10,455 24,562
Restricted cash 7,259 3,567
Tenant accounts receivable, net 34,013 33,602
Prepaid expenses and other assets 29,776 25,364
Interest rate swaps 12,577 6,079
Assets held for sale, net 13,498 19,916
Total assets 2,695,932 2,680,667
Liabilities:    
Unsecured credit facility 218,000 271,000
Unsecured term loans, net 521,506 446,265
Unsecured notes, net 398,226 398,234
Mortgage notes, net 57,851 58,282
Accounts payable, accrued expenses and other liabilities 38,294 43,216
Interest rate swaps 0 1,217
Tenant prepaid rent and security deposits 21,876 19,045
Dividends and distributions payable 14,460 11,880
Deferred leasing intangibles, net of accumulated amortization of $11,321 and $13,555, respectively 20,720 21,221
Total liabilities 1,290,933 1,270,360
Commitments and contingencies (Note 10)
Preferred stock, par value $0.01 per share, 15,000,000 shares authorized,    
Common stock, par value $0.01 per share, 150,000,000 shares authorized, 97,229,588 and 97,012,543 shares issued and outstanding at March 31, 2018 and December 31, 2017, respectively 972 970
Additional paid-in capital 1,724,627 1,725,825
Common stock dividends in excess of earnings (530,257) (516,691)
Accumulated other comprehensive income 11,581 3,936
Total stockholders’ equity 1,351,923 1,359,040
Noncontrolling interest 53,076 51,267
Total equity 1,404,999 1,410,307
Total liabilities and equity 2,695,932 2,680,667
Series B Preferred Stock    
Preferred stock, par value $0.01 per share, 15,000,000 shares authorized,    
Preferred stock 70,000 70,000
Series C Preferred Stock    
Preferred stock, par value $0.01 per share, 15,000,000 shares authorized,    
Preferred stock $ 75,000 $ 75,000
v3.8.0.1
Consolidated Balance Sheets (Parenthetical) - USD ($)
$ in Thousands
Mar. 31, 2018
Dec. 31, 2017
Building and Improvements $ 266,158 $ 249,057
Deferred leasing intangibles assets, accumulated amortization 215,597 280,642
Deferred leasing intangibles liabilities, accumulated amortization $ 11,321 $ 13,555
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 97,229,588 97,012,543
Common stock, shares outstanding 97,229,588 97,012,543
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) $ 25.00 $ 25.00
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) $ 25.00 $ 25.00
v3.8.0.1
Consolidated Statements of Operations - USD ($)
$ in Thousands
 3 Months Ended
Mar. 31, 2018
Mar. 31, 2017
Revenue    
Rental income $ 69,928 $ 59,222
Tenant recoveries 13,199 10,185
Other income 156 73
Total revenue 83,283 69,480
Expenses    
Property 17,499 13,276
General and administrative 8,748 8,771
Property acquisition costs 0 740
Depreciation and amortization 39,965 35,953
Loss on impairments 2,934 0
Loss on involuntary conversion 0 330
Other expenses 291 194
Total expenses 69,437 59,264
Other income (expense)    
Interest expense (11,386) (10,472)
Gain on the sales of rental property, net 22,689 325
Total other income (expense) 11,303 (10,147)
Net income 25,149 69
Less: income (loss) attributable to noncontrolling interest after preferred stock dividends 954 (103)
Net income attributable to STAG Industrial, Inc. 24,195 172
Less: preferred stock dividends 2,448 2,448
Less: amount allocated to participating securities 71 83
Net income (loss) attributable to common stockholders $ 21,676 $ (2,359)
Weighted average common shares outstanding — basic 97,021,000 81,808,000
Weighted average common shares outstanding — diluted 97,323,000 81,808,000
Net income (loss) per share — basic and diluted    
Net income (loss) per share attributable to common stockholders — basic $ 0.22 $ (0.03)
Net income (loss) per share attributable to common stockholders — diluted $ 0.22 $ (0.03)
v3.8.0.1
Consolidated Statements of Comprehensive Income (Loss) - USD ($)
$ in Thousands
 3 Months Ended
Mar. 31, 2018
Mar. 31, 2017
Statement of Comprehensive Income [Abstract]    
Net income $ 25,149 $ 69
Other comprehensive income:    
Income on interest rate swaps 7,723 1,212
Other comprehensive income 7,723 1,212
Comprehensive income 32,872 1,281
(Income) loss attributable to noncontrolling interest after preferred stock dividends (954) 103
Other comprehensive income attributable to noncontrolling interest (325) (52)
Comprehensive income attributable to STAG Industrial, Inc. $ 31,593 $ 1,332
v3.8.0.1
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
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 sales of common stock 68,543   $ 28 68,515     68,543  
Proceeds from sales of common stock (in shares)     2,843,907          
Offering costs (1,068)     (1,068)     (1,068)  
Dividends, Preferred Stock   2,448            
Dividends, Common Stock         28,881      
Dividends             31,329  
Dividends and Distributions, Net 33,143              
Distribution Made to Limited Partner, Cash Distributions Declared               1,814
Non-cash compensation activity, net 1,431     454     260 1,171
Non-cash compensation activity (in shares)     37,353          
Non-cash compensation activity (in excess of earnings)     $ 0   (194)      
Redemption of common units to common stock     $ 1 1,592     1,593 (1,593)
Redemption of common units to common stock (in shares)     145,029          
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          
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          
Balance at Dec. 31, 2017 1,410,307 145,000 $ 970 1,725,825 (516,691) 3,936 1,359,040 51,267
Balance (in shares) at Dec. 31, 2017     97,012,543          
Increase (Decrease) in Stockholders' Equity                
Cash flow hedging instruments cumulative effect adjustment (Note 2)         (258) 247 (11) 11
Offering costs (107)     (107)     (107)  
Dividends, Preferred Stock   2,448            
Dividends, Common Stock         34,518      
Dividends             36,966  
Dividends and Distributions, Net 38,779              
Distribution Made to Limited Partner, Cash Distributions Declared               1,813
Non-cash compensation activity, net 706     (855)     (1,391) 2,097
Non-cash compensation activity (in shares)     71,373          
Non-cash compensation activity (in excess of earnings)     $ (1)   (537)      
Redemption of common units to common stock     $ 1 1,823     1,824 (1,824)
Redemption of common units to common stock (in shares)     145,672          
Rebalancing of noncontrolling interest       (2,059)     (2,059) 2,059
Other comprehensive income 7,723         7,398 7,398 325
Net income 25,149 2,448     21,747   24,195 954
Balance at Mar. 31, 2018 $ 1,404,999 $ 145,000 $ 972 $ 1,724,627 $ (530,257) $ 11,581 $ 1,351,923 $ 53,076
Balance (in shares) at Mar. 31, 2018     97,229,588.000          
v3.8.0.1
Consolidated Statements of Cash Flows - USD ($)
$ in Thousands
 3 Months Ended 12 Months Ended
Mar. 31, 2018
Mar. 31, 2017
Dec. 31, 2017
Cash flows from operating activities:      
Net income $ 25,149 $ 69  
Adjustment to reconcile net income to net cash provided by operating activities:      
Depreciation and amortization 39,965 35,953  
Loss on impairments 2,934 0  
Loss on involuntary conversion 0 330  
Non-cash portion of interest expense 534 345  
Intangible amortization in rental income, net 1,207 1,296  
Straight-line rent adjustments, net (2,781) (967)  
Dividends on forfeited equity compensation 7 1  
Gain on the sales of rental property, net (22,689) (325)  
Non-cash compensation expense 2,220 2,387  
Change in assets and liabilities:      
Tenant accounts receivable, net 848 157  
Prepaid expenses and other assets (5,531) (5,723)  
Accounts payable, accrued expenses and other liabilities (2,720) (4,457)  
Tenant prepaid rent and security deposits 2,831 2,342  
Total adjustments 16,825 31,339  
Net cash provided by operating activities 41,974 31,408  
Cash flows from investing activities:      
Acquisitions of land and buildings and improvements (67,077) (84,689)  
Additions of land and building and improvements (6,317) (6,015)  
Proceeds from sales of rental property, net 49,631 3,919  
Proceeds from insurance on involuntary conversion 0 439  
Acquisition deposits, net (605) (645)  
Acquisitions of deferred leasing intangibles (11,744) (15,098)  
Net cash used in investing activities (36,112) (102,089)  
Cash flows from financing activities:      
Proceeds from unsecured credit facility 110,000 141,000  
Repayment of unsecured credit facility (163,000) (98,000)  
Proceeds from unsecured term loans 75,000 0  
Repayment of mortgage notes (462) (12,167)  
Payment of loan fees and costs (3) (35)  
Dividends and distributions 36,200 32,723  
Proceeds from sales of common stock 0 68,543  
Repurchase and retirement of share-based compensation (1,524) (969)  
Offering costs (88) (971)  
Net cash provided by (used in) financing activities (16,277) 64,678  
Decrease in cash and cash equivalents and restricted cash (10,415) (6,003)  
Cash and cash equivalents and restricted cash—beginning of period 28,129 21,805 $ 21,805
Cash and cash equivalents and restricted cash—end of period 17,714 15,802  
Supplemental disclosure:      
Cash paid for interest, net of capitalized interest 11,057 10,568  
Supplemental schedule of non-cash investing and financing activities      
Additions to building and other capital improvements 0 503  
Partial disposal of building due to involuntary conversion of building 0 221  
Investing other receivables due to involuntary conversion of building 0 (221)  
Change in additions of land, building, and improvements included in accounts payable, accrued expenses, and other liabilities 1,908 1,385  
Additions to building and other capital improvements from non-cash compensation (4) (7)  
Change in loan fees, costs, and offering costs included in accounts payable, accrued expenses, and other liabilities (90) (67)  
Dividends and distributions payable $ 14,460 $ 10,149 $ 11,880
v3.8.0.1
Organization and Description of Business
 3 Months Ended
Mar. 31, 2018
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 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, 2018 and December 31, 2017, the Company owned a 95.8% and 95.9%, 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, 2018, the Company owned 360 buildings in 37 states with approximately 70.8 million rentable square feet, consisting of 291 warehouse/distribution buildings, 55 light manufacturing buildings, and 14 flex/office buildings. The Company’s buildings were approximately 94.7% leased to 312 tenants as of March 31, 2018.
v3.8.0.1
Summary of Significant Accounting Policies
 3 Months Ended
Mar. 31, 2018
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, 2017.

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.

Reclassifications and New Accounting Standards

Certain prior year amounts have been reclassified to conform to the current year presentation.

New Accounting Standards Adopted

In August 2017, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2017-12, Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities. The purpose of this updated guidance is to better align a company’s financial reporting for hedging activities with the economic objectives of those activities. This standard is effective for fiscal years beginning after December 15, 2018 and interim periods within those years, with early adoption permitted, and the Company adopted this standard effective January 1, 2018 using the modified retrospective transition method. The adoption of this standard resulted in a cumulative effect adjustment of approximately $0.3 million recorded as an increase to common stock dividends in excess of earnings and an increase to accumulated other comprehensive income as of January 1, 2018 in the accompanying Consolidated Statements of Equity.

In May 2017, the FASB issued ASU 2017-09, Stock Compensation (Topic 718): Scope of Modification Accounting, which provides updated guidance about which changes to the terms or conditions of a share-based payment award would require an entity to apply modification accounting under the topic. This standard is effective for fiscal years beginning after December 15, 2017 and interim periods within those years, and the Company adopted this standard prospectively effective January 1, 2018. The adoption of this standard did not have a material effect on the Company's consolidated financial statements.

In February 2017, the FASB issued 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 was 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, which the Company adopted effective January 1, 2018. The Company adopted this standard effective January 1, 2018 using the modified retrospective approach. The adoption of this standard did not have a material effect on the Company's consolidated financial statements.

In January 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, and the Company adopted this standard prospectively effective January 1, 2018. As a result, it is expected that the majority of the Company's acquisitions will be accounted for as asset acquisitions, whereas under the former guidance the majority of the Company's acquisitions had been accounted for as business combinations. The most significant difference between the two accounting models that impacts 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.

In November 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 the Company adopted this standard effective January 1, 2018. As a result, the Company has included restricted cash with cash and cash equivalents when reconciling the beginning and end of period total amounts on the accompanying Consolidated Statements of Cash Flows. The effects of this standard were applied retrospectively to all prior periods presented. For the three months ended March 31, 2017, the effect of the change in accounting principle was an increase in cash provided by operating activities of approximately $0.3 million and an increase in cash used in investing activities of approximately $1.1 million on the accompanying Consolidated Statements of Cash Flows.

In January 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, and the Company adopted this standard prospectively effective January 1, 2018. The adoption of this standard did not have a material effect on the Company's consolidated financial statements.

In May 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 below) 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 may 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 upon the adoption of ASU 2016-02 on January 1, 2019. Additionally, the new revenue guidance requires improved disclosures regarding the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers. The Company adopted this standard effective January 1, 2018 using the modified retrospective approach. The adoption of this standard did not have a material effect on the Company's consolidated financial statements.

New Accounting Standards Issued but not yet Adopted

In February 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 plans to adopt this standard effective January 1, 2019.

Restricted Cash

Restricted cash may include tenant security deposits and cash held in escrow for real estate taxes and capital improvements as required in various mortgage note agreements. Restricted cash also may include amounts held by the Company’s transfer agent for preferred stock dividends that are distributed subsequent to period end. The following table presents a reconciliation of cash and cash equivalents and restricted cash reported on the accompanying Consolidated Balance Sheets to amounts reported on the accompanying Consolidated Statements of Cash Flows (in thousands).
 
 
As of March 31,
 
 
2018
 
2017
Cash and cash equivalents
 
$
10,455

 
$
7,082

Restricted cash
 
7,259

 
8,720

Total cash and cash equivalents and restricted cash
 
$
17,714

 
$
15,802



Tenant Accounts Receivable, net

As of March 31, 2018 and December 31, 2017, the Company had an allowance for doubtful accounts of approximately $0.1 million and $0.1 million, respectively.

As of March 31, 2018 and December 31, 2017, the Company had accrued rental income, net of allowance of approximately $25.9 million and $24.7 million, respectively. As of March 31, 2018 and December 31, 2017, the Company had an allowance on accrued rental income of $0.1 million and $0.2 million, respectively.

As of March 31, 2018 and December 31, 2017, the Company had approximately $12.7 million and $12.7 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, 2018 and December 31, 2017, the Company had approximately $7.7 million and $7.4 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 $0.7 million and $0.7 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, 2018 and December 31, 2017, the Company's total liability associated with these lease security deposits was approximately $8.4 million and $8.1 million, respectively, and is included in tenant prepaid rent and security deposits on the accompanying Consolidated Balance Sheets.

Related Parties

As of March 31, 2018 and December 31, 2017, the Company had approximately $4,000 and $0, 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 $3.1 million for the three months ended March 31, 2018 and 2017, 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

Approximately $0.1 million and $39,000 of termination fee income related to the Buena Vista, VA property, the tenant at which exercised its early lease termination option on March 27, 2017, is included in rental income on the accompanying Consolidated Statements of Operations for the three months ended March 31, 2018 and 2017, respectively.

Gain on the Sales of Rental Property, net

The timing of the derecognition of a rental property and the corresponding recognition of gain on the sales of rental property, net is measured by various criteria related to the terms of the sale transaction, and if the Company has lost control of the property and the acquirer has gained control of the property after the transaction. If the derecognition criteria is met, the full gain is recognized.

Taxes

Federal Income Taxes

The Company's taxable REIT subsidiaries recognized a net loss of approximately $36,000 and $31,000 for the three months ended March 31, 2018 and 2017, 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, 2018 and 2017, respectively.

Uncertain Tax Positions

As of March 31, 2018 and December 31, 2017, 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.
v3.8.0.1
Rental Property
 3 Months Ended
Mar. 31, 2018
Real Estate [Abstract]  
Rental Property
Rental Property

The following table summarizes the components of rental property as of March 31, 2018 and December 31, 2017.
Rental Property (in thousands)
 
March 31, 2018
 
December 31, 2017
Land
 
$
324,734

 
$
321,560

Buildings, net of accumulated depreciation of $171,058 and $160,281, respectively
 
1,784,897

 
1,756,579

Tenant improvements, net of accumulated depreciation of $33,669 and $32,714, respectively
 
29,648

 
30,138

Building and land improvements, net of accumulated depreciation of $61,431 and $56,062, respectively
 
141,936

 
143,170

Construction in progress
 
1,951

 
2,877

Deferred leasing intangibles, net of accumulated amortization of $215,597 and $280,642, respectively
 
305,188

 
313,253

Total rental property, net
 
$
2,588,354

 
$
2,567,577



Acquisitions

The following table summarizes the acquisitions of the Company during the three months ended March 31, 2018.
Location
 
Square Feet
 
Buildings
 
Purchase Price
(in thousands)
Fountain Inn, SC
 
203,000

 
1

 
$
10,755

Bloomington, MN
 
145,351

 
1

 
13,538

York, PA
 
278,582

 
1

 
18,277

Houston, TX
 
242,225

 
2

 
22,478

Greer, SC
 
222,710

 
1

 
13,773

Three months ended March 31, 2018
 
1,091,868

 
6

 
$
78,821



The following table summarizes the allocation of the consideration paid at the date of acquisition during the three months ended March 31, 2018 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
 
$
6,415

 
N/A
Buildings
 
57,248

 
N/A
Tenant improvements
 
996

 
N/A
Building and land improvements
 
2,418

 
N/A
Deferred leasing intangibles - In-place leases
 
8,122

 
6.3
Deferred leasing intangibles - Tenant relationships
 
3,712

 
10.5
Deferred leasing intangibles - Above market leases
 
583

 
5.8
Deferred leasing intangibles - Below market leases
 
(673
)
 
9.7
Total purchase price
 
$
78,821

 
 


The table below sets forth the results of operations for the three months ended March 31, 2018 for the buildings acquired during the three months ended March 31, 2018 included in the Company’s Consolidated Statements of Operations from the date of acquisition.
Results of Operations (in thousands)
 
Three months ended March 31, 2018
Total revenue
 
$
924

Net loss
 
$
104



Dispositions

During the three months ended March 31, 2018, the Company sold two buildings comprised of approximately 0.7 million square feet with a net book value of approximately $26.9 million to third parties. These buildings contributed approximately $0.3 million and $0.9 million to revenue for the three months ended March 31, 2018 and 2017, respectively. These buildings contributed approximately $49,000 and $46,000 to net income (exclusive of loss on involuntary conversion and gain on the sales of rental property, net) for the three months ended March 31, 2018 and 2017, respectively. Net proceeds from the sales of rental property were approximately $49.6 million and the Company recognized the full gain on the sales of rental property, net of approximately $22.7 million for the three months ended March 31, 2018.

Assets Held for Sale

As of March 31, 2018, the related land, building and improvements, net, and deferred leasing intangibles, net, of approximately $2.0 million, $10.7 million, and $0.8 million, respectively, for two buildings were classified as assets held for sale, net on the accompanying Consolidated Balance Sheets. These buildings contributed approximately $0.2 million and $0.5 million to revenue for the three months ended March 31, 2018 and 2017, respectively. These buildings contributed a net loss of approximately $0.8 million and $29,000 to net income for the three months ended March 31, 2018 and 2017, respectively.

Loss on Impairments

The following table summarizes the Company's loss on impairments for assets held and used during the three months ended March 31, 2018.
Property Location
 
Buildings
 
Event or Change in Circumstance Leading to Impairment Evaluation(1)
 
Valuation technique utilized to estimate fair value
 
Fair Value(2)
 
Loss on Impairments
(in thousands)
Buena Vista, VA
 
1
 
Change in estimated hold period
(3)
Discounted cash flows
 
 
 
 
Sergeant Bluff, IA
 
1
 
Change in estimated hold period
(3)
Discounted cash flows
 
 
 
 
Three months ended March 31, 2018
 
 
 
$
3,176

 
$
2,934

(1)
The Company tested the asset group for impairment utilizing a probability weighted recovery analysis of certain scenarios, and it was determined that the carrying value of the property and intangibles were not recoverable from the estimated future undiscounted cash flows.
(2)
The estimated fair value of the property is based on Level 3 inputs and is a non-recurring fair value measurement. Level 3 is defined as unobservable inputs in which little or no market data exists, therefore requiring an entity to develop its own assumptions.
(3)
Level 3 inputs used to determine fair value for the properties impaired for the three months ended March 31, 2018: discount rates ranged from 11.0% to 14.5% and exit capitalization rates ranged from 11.0% to 13.0%.

Deferred Leasing Intangibles

The following table sets forth the deferred leasing intangibles on the accompanying Consolidated Balance Sheets as of March 31, 2018 and December 31, 2017.
 
 
March 31, 2018
 
December 31, 2017
Deferred Leasing Intangibles (in thousands)
 
Gross
 
Accumulated Amortization
 
Net
 
Gross
 
Accumulated Amortization
 
Net
Above market leases
 
$
70,675

 
$
(30,725
)
 
$
39,950

 
$
78,558

 
$
(36,810
)
 
$
41,748

Other intangible lease assets
 
450,110

 
(184,872
)
 
265,238

 
515,337

 
(243,832
)
 
271,505

Total deferred leasing intangible assets
 
$
520,785

 
$
(215,597
)
 
$
305,188

 
$
593,895

 
$
(280,642
)
 
$
313,253

 
 
 
 
 
 
 
 
 
 
 
 
 
Below market leases
 
$
32,041

 
$
(11,321
)
 
$
20,720

 
$
34,776

 
$
(13,555
)
 
$
21,221

Total deferred leasing intangible liabilities
 
$
32,041

 
$
(11,321
)
 
$
20,720

 
$
34,776

 
$
(13,555
)
 
$
21,221


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, 2018 and 2017.
 
 
Three months ended March 31,
Deferred Leasing Intangibles Amortization (in thousands)
 
2018
 
2017
Net decrease to rental income related to above and below market lease amortization
 
$
1,207

 
$
1,296

Amortization expense related to other intangible lease assets
 
$
18,100

 
$
18,393



The following table sets forth the amortization of deferred leasing intangibles over the next five calendar years beginning with 2018 as of March 31, 2018.
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 2018
 
$
48,805

 
$
2,987

2019
 
$
50,905

 
$
3,846

2020
 
$
40,954

 
$
3,504

2021
 
$
30,242

 
$
2,178

2022
 
$
23,113

 
$
1,210
v3.8.0.1
Debt
 3 Months Ended
Mar. 31, 2018
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, 2018 and December 31, 2017.
Loan

Principal Outstanding as of March 31, 2018 (in thousands)
    
Principal Outstanding as of December 31, 2017 (in thousands)
 
Interest 
Rate (1)
    
Maturity Date
 
Prepayment Terms (2) 
Unsecured credit facility:


 

 





Unsecured Credit Facility (3)

$
218,000

  
$
271,000

 
L + 1.15%


Dec-18-2019

i
Total unsecured credit facility

218,000

  
271,000

 
 


 

 
 


 

 





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
Unsecured Term Loan D (4)
 
75,000

  
—

 
L + 1.30%

 
Jan-04-2023
 
i
Total unsecured term loans

525,000

 
450,000

 






Less: Total unamortized deferred financing fees and debt issuance costs

(3,494
)
 
(3,735
)
 






Total carrying value unsecured term loans, net

521,506

  
446,265

 
 


 

 
 


 

 





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

(1,774
)
 
(1,766
)
 






Total carrying value unsecured notes, net

398,226

  
398,234

  
 


 

 
 


 

 





Mortgage notes (secured debt):

 

 


 
 


 

 
Wells Fargo Bank, National Association CMBS Loan

54,515

  
54,949

 
4.31
%

Dec-1-2022

iii
Thrivent Financial for Lutherans
 
3,879

 
3,906

 
4.78
%
 
Dec-15-2023
 
iv
Total mortgage notes

58,394

  
58,855

 
 





Total unamortized fair market value premiums

58

 
61

 
 





Less: Total unamortized deferred financing fees and debt issuance costs 

(601
)
 
(634
)
 






Total carrying value mortgage notes, net

57,851

  
58,282

 
 





Total / weighted average interest rate (5)

$
1,195,583

  
$
1,173,781

 
3.56
%





(1)
Interest rate as of March 31, 2018. At March 31, 2018, the one-month LIBOR (“L”) was 1.88313%. The 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 three months prior to the maturity date, however can be defeased beginning January 1, 2016; and (iv) pre-payable without penalty three months prior to the maturity date.
(3)
The capacity of the unsecured credit facility is $450.0 million. Deferred financing fees and debt issuance costs, net of accumulated amortization related to the unsecured credit facility of approximately $1.3 million and $1.5 million is included in prepaid expenses and other assets on the accompanying Consolidated Balance Sheets as of March 31, 2018 and December 31, 2017, respectively.
(4)
The remaining capacity is $75.0 million, which the Company has until July 27, 2018 to draw.
(5)
The weighted average interest rate was calculated using the fixed interest rate swapped on the notional amount of $600.0 million of debt that was in effect as of March 31, 2018, 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 and unsecured term loans as of March 31, 2018 was approximately $301.1 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 $5.4 million and $5.6 million as of March 31, 2018 and December 31, 2017, 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, 2018 and 2017.
 
 
Three months ended March 31,
Costs Included in Interest Expense (in thousands)
 
2018
 
2017
Amortization of deferred financing fees and debt issuance costs and fair market value premiums
 
$
534

 
$
501

Facility fees and unused fees
 
$
339

 
$
275



On March 28, 2018, the Company drew $75.0 million of the $150.0 million unsecured term loan that was entered into on July 28, 2017.

Financial Covenant Considerations

The Company was in compliance with all financial and other covenants as of March 31, 2018 and December 31, 2017 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 $89.8 million and $90.9 million at March 31, 2018 and December 31, 2017, respectively, and is limited to senior, property-level secured debt financing arrangements.

Fair Value of Debt

The following table presents the aggregate principal outstanding under the Company’s debt arrangements and the corresponding estimate of fair value as of March 31, 2018 and December 31, 2017 (in thousands).
 
 
March 31, 2018
 
December 31, 2017
 
 
Principal Outstanding
 
Fair Value
 
Principal Outstanding
 
Fair Value
Unsecured credit facility
 
$
218,000

 
$
218,371

 
$
271,000

 
$
271,528

Unsecured term loans
 
525,000

 
526,685

 
450,000

 
451,463

Unsecured notes
 
400,000

 
410,058

 
400,000

 
415,599

Mortgage notes
 
58,394

 
58,611

 
58,855

 
59,769

Total principal amount
 
1,201,394

 
$
1,213,725

 
1,179,855

 
$
1,198,359

Add: Total unamortized fair market value premiums
 
58

 
 
 
61

 
 
Less: Total unamortized deferred financing fees and debt issuance costs
 
(5,869
)
 
 
 
(6,135
)
 
 
Total carrying value
 
$
1,195,583

 
 
 
$
1,173,781

 
 


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.
v3.8.0.1
Use of Derivative Financial Instruments
 3 Months Ended
Mar. 31, 2018
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, 2018. All of the Company's interest rate swaps are designated as qualifying cash flow hedges.
Interest Rate
Derivative Counterparty
 
Trade Date    
 
Effective Date
 
Notional Amount
(in thousands)
 
Fair Value
(in thousands)
 
Pay Fixed Interest Rate
 
Receive Variable Interest Rate
 
Maturity Date
Regions Bank
 
Mar-01-2013
 
Mar-01-2013
 
$
25,000

 
$
461

 
1.3300
%
 
One-month L
 
Feb-14-2020 
Capital One, N.A.
 
Jun-13-2013
 
Jul-01-2013
 
$
50,000

 
$
595

 
1.6810
%
 
One-month L
 
Feb-14-2020 
Capital One, N.A.
 
Jun-13-2013
 
Aug-01-2013
 
$
25,000

 
$
287

 
1.7030
%
 
One-month L
 
Feb-14-2020 
Regions Bank
 
Sep-30-2013
 
Feb-03-2014
 
$
25,000

 
$
153

 
1.9925
%
 
One-month L
 
Feb-14-2020 
The Toronto-Dominion Bank
 
Oct-14-2015
 
Sep-29-2016
 
$
25,000

 
$
622

 
1.3830
%
 
One-month L
 
Sep-29-2020
PNC Bank, N.A.
 
Oct-14-2015
 
Sep-29-2016
 
$
50,000

 
$
1,237

 
1.3906
%
 
One-month L
 
Sep-29-2020
Regions Bank
 
Oct-14-2015
 
Sep-29-2016
 
$
35,000

 
$
870

 
1.3858
%
 
One-month L
 
Sep-29-2020
U.S. Bank, N.A.
 
Oct-14-2015
 
Sep-29-2016
 
$
25,000

 
$
618

 
1.3950
%
 
One-month L
 
Sep-29-2020
Capital One, N.A.
 
Oct-14-2015
 
Sep-29-2016
 
$
15,000

 
$
370

 
1.3950
%
 
One-month L
 
Sep-29-2020
Royal Bank of Canada
 
Jan-08-2015
 
Mar-20-2015
 
$
25,000

 
$
529

 
1.7090
%
 
One-month L
 
Mar-21-2021
The Toronto-Dominion Bank
 
Jan-08-2015
 
Mar-20-2015
 
$
25,000

 
$
526

 
1.7105
%
 
One-month L
 
Mar-21-2021
The Toronto-Dominion Bank
 
Jan-08-2015
 
Sep-10-2017
 
$
100,000

 
$
615

 
2.2255
%
 
One-month L
 
Mar-21-2021
Wells Fargo, N.A.
 
Jan-08-2015
 
Mar-20-2015
 
$
25,000

 
$
646

 
1.8280
%
 
One-month L
 
Mar-31-2022
The Toronto-Dominion Bank
 
Jan-08-2015
 
Feb-14-2020
 
$
25,000

 
$
105

 
2.4535
%
 
One-month L
 
Mar-31-2022
Regions Bank
 
Jan-08-2015
 
Feb-14-2020
 
$
50,000

 
$
188

 
2.4750
%
 
One-month L
 
Mar-31-2022
Capital One, N.A.
 
Jan-08-2015
 
Feb-14-2020
 
$
50,000

 
$
135

 
2.5300
%
 
One-month L
 
Mar-31-2022
The Toronto-Dominion Bank
 
Jul-20-2017
 
Oct-30-2017
 
$
25,000

 
$
768

 
1.8485
%
 
One-month L
 
Jan-04-2023
Royal Bank of Canada
 
Jul-20-2017
 
Oct-30-2017
 
$
25,000

 
$
770

 
1.8505
%
 
One-month L
 
Jan-04-2023
Wells Fargo, N.A.
 
Jul-20-2017
 
Oct-30-2017
 
$
25,000

 
$
770

 
1.8505
%
 
One-month L
 
Jan-04-2023
PNC Bank, N.A.
 
Jul-20-2017
 
Oct-30-2017
 
$
25,000

 
$
770

 
1.8485
%
 
One-month L
 
Jan-04-2023
PNC Bank, N.A.
 
Jul-20-2017
 
Oct-30-2017
 
$
50,000

 
$
1,542

 
1.8475
%
 
One-month L
 
Jan-04-2023


The fair value of the interest rate swaps outstanding as of March 31, 2018 and December 31, 2017 was as follows.
Balance Sheet Line Item (in thousands)
 
Notional Amount March 31, 2018
 
Fair Value
March 31, 2018
 
Notional Amount December 31, 2017
 
Fair Value December 31, 2017
Interest rate swaps-Asset
 
$
725,000

 
$
12,577

 
$
475,000

 
$
6,079

Interest rate swaps-Liability
 
$
—

 
$
—

 
$
250,000

 
$
(1,217
)


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. 

For derivatives designated and that qualify as cash flow hedges of interest rate risk, the gain or loss on the derivative is recorded in accumulated other comprehensive income and subsequently reclassified into interest expense in the same periods during which the hedged transaction affects earnings.

Amounts reported in accumulated other comprehensive income 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 $2.3 million will be reclassified from accumulated other comprehensive income as a decrease to interest expense over the next 12 months.

The table below presents the effect of cash flow hedge accounting and the location in the consolidated financial statements for the three months ended March 31, 2018 and 2017 (in thousands).
 
 
Three months ended March 31,
 
 
2018
 
2017
Income recognized in accumulated other comprehensive income on interest rate swaps
 
$
7,493

 
$
514

Loss reclassified from accumulated other comprehensive income into income (loss) as interest expense
 
$
230

 
$
698

Total interest expense presented in the Consolidated Statements of Operations in which the effects of cash flow hedges are recorded

 
$
11,386

 
$
10,472



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, 2018, the Company had no derivatives that were in a net liability position by counterparty.

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, 2018 and December 31, 2017, 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, 2018 and December 31, 2017. 
 
 
 
 
Fair Value Measurements as of
March 31, 2018 Using
Balance Sheet Line Item (in thousands)
 
Fair Value
March 31, 2018
 
Level 1
 
Level 2
 
Level 3
Interest rate swaps-Asset
 
$
12,577

 
$
—

 
$
12,577

 
$
—

Interest rate swaps-Liability
 
$
—

 
$
—

 
$
—

 
$
—


 
 
 
 
Fair Value Measurements as of
December 31, 2017 Using
Balance Sheet Line Item (in thousands)
 
Fair Value December 31, 2017
 
Level 1
 
Level 2
 
Level 3
Interest rate swaps-Asset
 
$
6,079

 
$
—

 
$
6,079

 
$
—

Interest rate swaps-Liability
 
$
(1,217
)
 
$
—

 
$
(1,217
)
 
$
—
v3.8.0.1
Equity
 3 Months Ended
Mar. 31, 2018
Stockholders' Equity Note [Abstract]  
Equity
Equity

Preferred Stock

The table below sets forth the Company’s outstanding preferred stock issuances as of March 31, 2018.
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, 2018 and the year ended December 31, 2017.
Quarter Ended 2018
 
Declaration Date
 
Series B
Preferred Stock Per Share
 
Series C
Preferred Stock Per Share
 
Payment Date
March 31
 
February 14, 2018

0.4140625


0.4296875


April 2, 2018
Total
 
 

$
0.4140625


$
0.4296875


 
Quarter Ended 2017
 
Declaration Date
 
Series B Preferred Stock Per Share
 
Series C Preferred Stock Per Share
 
Payment Date
December 31
 
November 2, 2017
 
$
0.4140625

 
$
0.4296875

 
December 29, 2017
September 30
 
July 31, 2017
 
0.4140625

 
0.4296875

 
September 29, 2017
June 30
 
May 1, 2017
 
0.4140625

 
0.4296875

 
June 30, 2017
March 31
 
February 15, 2017
 
0.4140625

 
0.4296875

 
March 31, 2017
Total
 
 
 
$
1.6562500

 
$
1.7187500

 
 


On April 10, 2018, the Company’s board of directors declared the Series B Preferred Stock and Series C Preferred Stock dividends for the quarter ending June 30, 2018 at a quarterly rate of $0.4140625 per share and $0.4296875 per share, respectively.

Common Stock

The following table sets forth the terms of the Company’s at-the market (“ATM”) common stock offering program as of March 31, 2018.
ATM Common Stock Offering Program
 
Date
 
Maximum Aggregate Offering Price (in thousands)

Aggregate Common Stock Available as of
March 31, 2018 (in thousands)
2017 $500 million ATM
 
November 13, 2017
 
$
500,000

 
$
489,674


The table below set forth the activity under the ATM common stock offering programs during the year ended December 31, 2017 (in thousands, except share data). There was no activity under the ATM common stock offering programs during three months ended March 31, 2018.
 
 
Year ended December 31, 2017
ATM Common Stock Offering Program
 
Shares
Sold
 
Weighted Average Price Per Share
 
Gross
Proceeds
 
Sales
Agents’ Fee
 
Net
Proceeds
2017 $500 million ATM
 
363,843

 
$
28.38

 
$
10,326

 
$
129

 
$
10,197

2017 $300 million ATM(1)
 
11,098,748

 
$
27.03

 
300,000

 
3,637

 
296,363

2016 $228 million ATM(1)
 
4,799,784

 
$
24.42

 
117,216

 
1,604

 
115,612

Total/weighted average
 
16,262,375

 
$
26.29

 
$
427,542

 
$
5,370

 
$
422,172


(1)
These programs ended before December 31, 2017.

Dividends

The table below sets forth the dividends attributable to the Company's outstanding shares of common stock that were declared during the three months ended March 31, 2018 and the year ended December 31, 2017.
Month Ended 2018

Declaration Date
 
Record Date
 
Per Share
 
Payment Date
March 31

November 2, 2017

March 29, 2018

0.118333


April 16, 2018
February 28

November 2, 2017

February 28, 2018

0.118333


March 15, 2018
January 31

November 2, 2017

January 31, 2018

0.118333


February 15, 2018
Total

 
 
 

$
0.354999


 
Month Ended 2017
 
Declaration Date
 
Record Date
 
Per Share
 
Payment Date
December 31
 
July 31, 2017
 
December 29, 2017
 
$
0.117500

 
January 16, 2018
November 30
 
July 31, 2017
 
November 30, 2017
 
0.117500

 
December 15, 2017
October 31
 
July 31, 2017
 
October 31, 2017
 
0.117500

 
November 15, 2017
September 30
 
May 1, 2017
 
September 29, 2017
 
0.117500

 
October 16, 2017
August 31
 
May 1, 2017
 
August 31, 2017
 
0.117500

 
September 15, 2017
July 31
 
May 1, 2017
 
July 31, 2017
 
0.117500

 
August 15, 2017
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
 
 
 
 
 
$
1.405002

 
 


On April 10, 2018, the Company’s board of directors declared the common stock dividends for the months ending April 30, 2018, May 31, 2018 and June 30, 2018 at a monthly rate of $0.118333 per share of common stock.

Restricted Stock-Based Compensation

Restricted shares of common stock granted on January 5, 2018 to certain employees of the Company, subject to the recipient’s continued employment, will vest in four equal installments on January 1 of each year beginning in 2019. The following table summarizes activity related to the Company’s unvested restricted shares of common stock for the three months ended March 31, 2018 and the year ended December 31, 2017.
Unvested Restricted Shares of Common Stock
 
Shares
    
Balance at December 31, 2016
 
272,337

 
Granted
 
75,001

(1)
Vested
 
(109,209
)
(2)
Forfeited
 
(922
)
 
Balance at December 31, 2017
 
237,207

 
Granted
 
76,659

(1)
Vested
 
(112,405
)
(2)
Forfeited
 
(5,090
)
 
Balance at March 31, 2018
 
196,371

 
(1)
The fair value per share on the grant date of January 5, 2018 and January 6, 2017 was $26.40 and $24.41, respectively.
(2)
The Company repurchased and retired 41,975 and 40,836 restricted shares of common stock that vested during the three months ended March 31, 2018 and the year ended December 31, 2017, respectively.

The unrecognized compensation expense associated with the Company’s restricted shares of common stock at March 31, 2018 was approximately $4.1 million and is expected to be recognized over a weighted average period of approximately 2.9 years.

The following table summarizes the fair value at vesting for the restricted shares of common stock that vested during the three months ended March 31, 2018 and 2017. 
 
 
Three months ended March 31,
 
 
2018
 
2017
Vested restricted shares of common stock
 
112,405

 
109,209

Fair value of vested restricted shares of common stock (in thousands)
 
$
3,002

 
$
2,591
v3.8.0.1
Noncontrolling Interest
 3 Months Ended
Mar. 31, 2018
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, 2018 and the year ended December 31, 2017.
 
LTIP Units
 
Other
Common Units
 
Total
Noncontrolling Common Units
 
Noncontrolling Interest
Balance at December 31, 2016
1,576,516

 
2,057,365

 
3,633,881

 
4.3
%
Granted/Issued
126,239

 
687,827

 
814,066

 
N/A

Forfeited
—

 
—

 
—

 
N/A

Conversions from LTIP units to Other Common Units
(245,685
)
 
245,685

 
—

 
N/A

Redemptions from Other Common Units to common stock
—

 
(351,260
)
 
(351,260
)
 
N/A

Balance at December 31, 2017
1,457,070

 
2,639,617

 
4,096,687

 
4.1
%
Granted/Issued
324,802

 
—

 
324,802

 
N/A

Forfeited
—

 
—

 
—

 
N/A

Conversions from LTIP units to Other Common Units
(145,672
)
 
145,672

 
—

 
N/A

Redemptions from Other Common Units to common stock
—

 
(145,672
)
 
(145,672
)
 
N/A

Balance at March 31, 2018
1,636,200

 
2,639,617

 
4,275,817

 
4.2
%


LTIP Units

On March 12, 2018, the Company's board of directors appointed Michelle Dilley to serve as director of the Company and serve as a member of the nominating and corporate governance committee of the board of directors, effective on March 12, 2018. On March 12, 2018, Ms. Dilley was granted 3,930 LTIP units which, subject to Ms. Dilley's continued service, will vest on January 1, 2019.

LTIP units granted on January 5, 2018 to non-employee, independent directors, subject to the recipient’s continued service, will vest on January 1, 2019. LTIP units granted on January 5, 2018 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 having been March 31, 2018. Refer to Note 8 for a discussion of vested LTIP units granted on January 5, 2018 pursuant to the 2015 Outperformance Program (the “2015 OPP”).

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, 2018 (excluding those vested LTIP units granted pursuant to the 2015 OPP; refer to Note 8 for details).
LTIP Units
 
Assumptions
Grant date
 
March 12, 2018

 
January 5, 2018

Expected term (years)
 
10

 
10

Expected volatility
 
22.0
%
 
22.0
%
Expected dividend yield
 
6.0
%
 
6.0
%
Risk-free interest rate
 
2.46
%
 
2.09
%
Fair value of LTIP units at issuance (in thousands)
 
$
90

 
$
3,447

LTIP units at issuance
 
3,930

 
137,616

Fair value unit price per LTIP unit at issuance
 
$
22.90

 
$
25.05



The following table summarizes activity related to the Company’s unvested LTIP units for the three months ended March 31, 2018 and the year ended December 31, 2017.
Unvested LTIP Units
 
LTIP Units
Balance at December 31, 2016
 
403,423

Granted
 
126,239

Vested
 
(229,355
)
Forfeited
 
—

Balance at December 31, 2017
 
300,307

Granted
 
324,802

Vested
 
(231,041
)
Forfeited
 
—

Balance at March 31, 2018
 
394,068



The unrecognized compensation expense associated with the Company’s LTIP units at March 31, 2018 was approximately $7.5 million and is expected to be recognized over a weighted average period of approximately 2.8 years.

The following table summarizes the fair value at vesting for the LTIP units that vested during the three months ended March 31, 2018 and 2017.
 
 
Three months ended March 31,
 
 
2018
 
2017
Vested LTIP units
 
231,041

 
67,670

Fair value of vested LTIP units (in thousands)
 
$
6,035

 
$
1,664
v3.8.0.1
Equity Incentive Plan
 3 Months Ended
Mar. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]  
Equity Incentive Plan
Equity Incentive Plan

On January 5, 2018, the Company granted performance units approved by the compensation committee of the board of directors, under the 2011 Plan to certain key employees of the Company. The terms of the performance units granted on January 5, 2018 are substantially the same as the terms of the performance units granted on January 6, 2017 and March 8, 2016, except that the measuring period commences on January 1, 2018 and ends on December 31, 2020.

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 performance unit equity compensation expense is recognized into earnings ratably from the grant date over the respective vesting periods. The table below sets forth the assumptions used in valuing the performance units granted during the three months ended March 31, 2018.
Performance Units
 
Assumptions
Grant date
 
January 5, 2018

Expected volatility
 
22.0
%
Expected dividend yield
 
6.0
%
Risk-free interest rate
 
2.09
%
Fair value of performance units grant (in thousands)
 
$
5,456



On January 1, 2018, the Company’s three year measurement period pursuant to the 2015 OPP concluded. It was determined that the Company's total stockholder return exceeded the threshold percentage and return hurdle and a pool of approximately $6.2 million was awarded to the participants. The compensation committee of the board of directors approved the issuance of 183,256 vested LTIP units and 53,722 vested shares of common stock (of which 15,183 shares of common stock were repurchased and retired) to the participants, all of which were issued on January 5, 2018.

The unrecognized compensation expense associated with the Company's performance units at March 31, 2018 was approximately $7.8 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 units, the 2015 OPP (performance units and the 2015 OPP, collectively the “Performance-based Compensation Plans”), and the Company’s director compensation for the three months ended March 31, 2018 and 2017.
 
 
Three months ended March 31,
Non-Cash Compensation Expense (in thousands)
 
2018
    
2017
Restricted shares of common stock
 
$
434

  
$
592

LTIP units
 
871

 
1,170

Performance-based Compensation Plans
 
829

 
537

Director compensation (1)
 
86

 
88

Total non-cash compensation expense
 
$
2,220

 
$
2,387

(1)
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, 2018 and 2017. 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.
v3.8.0.1
Earnings Per Share
 3 Months Ended
Mar. 31, 2018
Earnings Per Share [Abstract]  
Earnings Per Share
Earnings Per Share

During the three months ended March 31, 2018 and 2017, there were 201,650 and 239,827, respectively, of unvested restricted shares of common stock on a weighted average basis that were considered participating securities.

The following table sets forth the computation of basic and diluted earnings per common share for the three months ended March 31, 2018 and 2017.
 
Three months ended March 31,
Earnings Per Share (in thousands, except per share data)
2018
 
2017
Numerator
 
 
 
Net income
$
25,149

 
$
69

Less: preferred stock dividends
2,448

 
2,448

Less: amount allocated to participating securities
71

 
83

Less: income (loss) attributable to noncontrolling interest after preferred stock dividends
954

 
(103
)
Net income (loss) attributable to common stockholders
$
21,676


$
(2,359
)
Denominator
 

 
 
Weighted average common shares outstanding — basic
97,021

 
81,808

Effect of dilutive securities(1)
 
 
 
Share-based compensation
302

 
—

Weighted average common shares outstanding — diluted
97,323

 
81,808

Net income (loss) per share — basic and diluted
 
 
 
Net income (loss) per share attributable to common stockholders — basic
$
0.22

 
$
(0.03
)
Net income (loss) per share attributable to common stockholders — diluted
$
0.22

 
$
(0.03
)
(1)
During the three months ended March 31, 2018 and 2017, there were approximately 202 and 240, respectively, unvested restricted shares of common stock, respectively, 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. During the three months ended March 31, 2017, there were approximately 438 unvested shares under the Performance-based Compensation Plans 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.
v3.8.0.1
Commitments and Contingencies
 3 Months Ended
Mar. 31, 2018
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 has letters of credit of approximately $5.9 million as of March 31, 2018 related to construction projects and certain other agreements.
v3.8.0.1
Subsequent Events
 3 Months Ended
Mar. 31, 2018
Subsequent Events [Abstract]  
Subsequent Events
Subsequent Events

The following non-recognized subsequent events were noted.

On April 10, 2018, the Company entered into a note purchase agreement for the future private placement by the Operating Partnership of $75.0 million senior unsecured notes maturing June 13, 2025 with a fixed annual interest rate of 4.10%, and $100.0 million senior unsecured notes maturing June 13, 2028 with a fixed annual interest rate of 4.27%.
v3.8.0.1
Summary of Significant Accounting Policies (Policies)
 3 Months Ended
Mar. 31, 2018
Accounting Policies [Abstract]  
Revenue Recognition, Real Estate Transactions, Policy [Policy Text Block]
Gain on the Sales of Rental Property, net

The timing of the derecognition of a rental property and the corresponding recognition of gain on the sales of rental property, net is measured by various criteria related to the terms of the sale transaction, and if the Company has lost control of the property and the acquirer has gained control of the property after the transaction. If the derecognition criteria is met, the full gain is recognized.

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, 2017.
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.
Reclassification
Certain prior year amounts have been reclassified to conform to the current year presentation.
New Accounting Pronouncements

New Accounting Standards Adopted

In August 2017, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2017-12, Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities. The purpose of this updated guidance is to better align a company’s financial reporting for hedging activities with the economic objectives of those activities. This standard is effective for fiscal years beginning after December 15, 2018 and interim periods within those years, with early adoption permitted, and the Company adopted this standard effective January 1, 2018 using the modified retrospective transition method. The adoption of this standard resulted in a cumulative effect adjustment of approximately $0.3 million recorded as an increase to common stock dividends in excess of earnings and an increase to accumulated other comprehensive income as of January 1, 2018 in the accompanying Consolidated Statements of Equity.

In May 2017, the FASB issued ASU 2017-09, Stock Compensation (Topic 718): Scope of Modification Accounting, which provides updated guidance about which changes to the terms or conditions of a share-based payment award would require an entity to apply modification accounting under the topic. This standard is effective for fiscal years beginning after December 15, 2017 and interim periods within those years, and the Company adopted this standard prospectively effective January 1, 2018. The adoption of this standard did not have a material effect on the Company's consolidated financial statements.

In February 2017, the FASB issued 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 was 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, which the Company adopted effective January 1, 2018. The Company adopted this standard effective January 1, 2018 using the modified retrospective approach. The adoption of this standard did not have a material effect on the Company's consolidated financial statements.

In January 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, and the Company adopted this standard prospectively effective January 1, 2018. As a result, it is expected that the majority of the Company's acquisitions will be accounted for as asset acquisitions, whereas under the former guidance the majority of the Company's acquisitions had been accounted for as business combinations. The most significant difference between the two accounting models that impacts 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.

In November 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 the Company adopted this standard effective January 1, 2018. As a result, the Company has included restricted cash with cash and cash equivalents when reconciling the beginning and end of period total amounts on the accompanying Consolidated Statements of Cash Flows. The effects of this standard were applied retrospectively to all prior periods presented. For the three months ended March 31, 2017, the effect of the change in accounting principle was an increase in cash provided by operating activities of approximately $0.3 million and an increase in cash used in investing activities of approximately $1.1 million on the accompanying Consolidated Statements of Cash Flows.

In January 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, and the Company adopted this standard prospectively effective January 1, 2018. The adoption of this standard did not have a material effect on the Company's consolidated financial statements.

In May 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 below) 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 may 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 upon the adoption of ASU 2016-02 on January 1, 2019. Additionally, the new revenue guidance requires improved disclosures regarding the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers. The Company adopted this standard effective January 1, 2018 using the modified retrospective approach. The adoption of this standard did not have a material effect on the Company's consolidated financial statements.

New Accounting Standards Issued but not yet Adopted

In February 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 plans to adopt this standard effective January 1, 2019.
Restricted cash and cash equivalents, policy
Restricted Cash

Restricted cash may include tenant security deposits and cash held in escrow for real estate taxes and capital improvements as required in various mortgage note agreements. Restricted cash also may include amounts held by the Company’s transfer agent for preferred stock dividends that are distributed subsequent to period end.
v3.8.0.1
Summary of Significant Accounting Policies - Cash, Cash Equivalents and Restricted Cash (Tables)
 3 Months Ended
Mar. 31, 2018
Accounting Policies [Abstract]  
Schedule of Cash, Cash Equivalents and Restricted Cash
The following table presents a reconciliation of cash and cash equivalents and restricted cash reported on the accompanying Consolidated Balance Sheets to amounts reported on the accompanying Consolidated Statements of Cash Flows (in thousands).
 
 
As of March 31,
 
 
2018
 
2017
Cash and cash equivalents
 
$
10,455

 
$
7,082

Restricted cash
 
7,259

 
8,720

Total cash and cash equivalents and restricted cash
 
$
17,714

 
$
15,802
v3.8.0.1
Rental Property (Tables)
 3 Months Ended
Mar. 31, 2018
Real Estate [Abstract]  
Schedule of components of rental property
The following table summarizes the components of rental property as of March 31, 2018 and December 31, 2017.
Rental Property (in thousands)
 
March 31, 2018
 
December 31, 2017
Land
 
$
324,734

 
$
321,560

Buildings, net of accumulated depreciation of $171,058 and $160,281, respectively
 
1,784,897

 
1,756,579

Tenant improvements, net of accumulated depreciation of $33,669 and $32,714, respectively
 
29,648

 
30,138

Building and land improvements, net of accumulated depreciation of $61,431 and $56,062, respectively
 
141,936

 
143,170

Construction in progress
 
1,951

 
2,877

Deferred leasing intangibles, net of accumulated amortization of $215,597 and $280,642, respectively
 
305,188

 
313,253

Total rental property, net
 
$
2,588,354

 
$
2,567,577
Schedule of real estate properties acquired
The following table summarizes the acquisitions of the Company during the three months ended March 31, 2018.
Location
 
Square Feet
 
Buildings
 
Purchase Price
(in thousands)
Fountain Inn, SC
 
203,000

 
1

 
$
10,755

Bloomington, MN
 
145,351

 
1

 
13,538

York, PA
 
278,582

 
1

 
18,277

Houston, TX
 
242,225

 
2

 
22,478

Greer, SC
 
222,710

 
1

 
13,773

Three months ended March 31, 2018
 
1,091,868

 
6

 
$
78,821
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, 2018 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
 
$
6,415

 
N/A
Buildings
 
57,248

 
N/A
Tenant improvements
 
996

 
N/A
Building and land improvements
 
2,418

 
N/A
Deferred leasing intangibles - In-place leases
 
8,122

 
6.3
Deferred leasing intangibles - Tenant relationships
 
3,712

 
10.5
Deferred leasing intangibles - Above market leases
 
583

 
5.8
Deferred leasing intangibles - Below market leases
 
(673
)
 
9.7
Total purchase price
 
$
78,821

 
 
Schedule of pro forma information for acquired properties
The table below sets forth the results of operations for the three months ended March 31, 2018 for the buildings acquired during the three months ended March 31, 2018 included in the Company’s Consolidated Statements of Operations from the date of acquisition.
Results of Operations (in thousands)
 
Three months ended March 31, 2018
Total revenue
 
$
924

Net loss
 
$
104
Schedule of Finite-Lived Intangible Assets and Below Market Leases
The following table sets forth the deferred leasing intangibles on the accompanying Consolidated Balance Sheets as of March 31, 2018 and December 31, 2017.
 
 
March 31, 2018
 
December 31, 2017
Deferred Leasing Intangibles (in thousands)
 
Gross
 
Accumulated Amortization
 
Net
 
Gross
 
Accumulated Amortization
 
Net
Above market leases
 
$
70,675

 
$
(30,725
)
 
$
39,950

 
$
78,558

 
$
(36,810
)
 
$
41,748

Other intangible lease assets
 
450,110

 
(184,872
)
 
265,238

 
515,337

 
(243,832
)
 
271,505

Total deferred leasing intangible assets
 
$
520,785

 
$
(215,597
)
 
$
305,188

 
$
593,895

 
$
(280,642
)
 
$
313,253

 
 
 
 
 
 
 
 
 
 
 
 
 
Below market leases
 
$
32,041

 
$
(11,321
)
 
$
20,720

 
$
34,776

 
$
(13,555
)
 
$
21,221

Total deferred leasing intangible liabilities
 
$
32,041

 
$
(11,321
)
 
$
20,720

 
$
34,776

 
$
(13,555
)
 
$
21,221


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, 2018 and 2017.
 
 
Three months ended March 31,
Deferred Leasing Intangibles Amortization (in thousands)
 
2018
 
2017
Net decrease to rental income related to above and below market lease amortization
 
$
1,207

 
$
1,296

Amortization expense related to other intangible lease assets
 
$
18,100

 
$
18,393
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense
The following table sets forth the amortization of deferred leasing intangibles over the next five calendar years beginning with 2018 as of March 31, 2018.
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 2018
 
$
48,805

 
$
2,987

2019
 
$
50,905

 
$
3,846

2020
 
$
40,954

 
$
3,504

2021
 
$
30,242

 
$
2,178

2022
 
$
23,113

 
$
1,210
Below Market Lease, Future Amortization Income
The following table sets forth the amortization of deferred leasing intangibles over the next five calendar years beginning with 2018 as of March 31, 2018.
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 2018
 
$
48,805

 
$
2,987

2019
 
$
50,905

 
$
3,846

2020
 
$
40,954

 
$
3,504

2021
 
$
30,242

 
$
2,178

2022
 
$
23,113

 
$
1,210
v3.8.0.1
Debt (Tables)
 3 Months Ended
Mar. 31, 2018
Debt Disclosure [Abstract]  
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, 2018 and December 31, 2017.
Loan

Principal Outstanding as of March 31, 2018 (in thousands)
    
Principal Outstanding as of December 31, 2017 (in thousands)
 
Interest 
Rate (1)
    
Maturity Date
 
Prepayment Terms (2) 
Unsecured credit facility:


 

 





Unsecured Credit Facility (3)

$
218,000

  
$
271,000

 
L + 1.15%


Dec-18-2019

i
Total unsecured credit facility

218,000

  
271,000

 
 


 

 
 


 

 





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
Unsecured Term Loan D (4)
 
75,000

  
—

 
L + 1.30%

 
Jan-04-2023
 
i
Total unsecured term loans

525,000

 
450,000

 






Less: Total unamortized deferred financing fees and debt issuance costs

(3,494
)
 
(3,735
)
 






Total carrying value unsecured term loans, net

521,506

  
446,265

 
 


 

 
 


 

 





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

(1,774
)
 
(1,766
)
 






Total carrying value unsecured notes, net

398,226

  
398,234

  
 


 

 
 


 

 





Mortgage notes (secured debt):

 

 


 
 


 

 
Wells Fargo Bank, National Association CMBS Loan

54,515

  
54,949

 
4.31
%

Dec-1-2022

iii
Thrivent Financial for Lutherans
 
3,879

 
3,906

 
4.78
%
 
Dec-15-2023
 
iv
Total mortgage notes

58,394

  
58,855

 
 





Total unamortized fair market value premiums

58

 
61

 
 





Less: Total unamortized deferred financing fees and debt issuance costs 

(601
)
 
(634
)
 






Total carrying value mortgage notes, net

57,851

  
58,282

 
 





Total / weighted average interest rate (5)

$
1,195,583

  
$
1,173,781

 
3.56
%





(1)
Interest rate as of March 31, 2018. At March 31, 2018, the one-month LIBOR (“L”) was 1.88313%. The 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 three months prior to the maturity date, however can be defeased beginning January 1, 2016; and (iv) pre-payable without penalty three months prior to the maturity date.
(3)
The capacity of the unsecured credit facility is $450.0 million. Deferred financing fees and debt issuance costs, net of accumulated amortization related to the unsecured credit facility of approximately $1.3 million and $1.5 million is included in prepaid expenses and other assets on the accompanying Consolidated Balance Sheets as of March 31, 2018 and December 31, 2017, respectively.
(4)
The remaining capacity is $75.0 million, which the Company has until July 27, 2018 to draw.
(5)
The weighted average interest rate was calculated using the fixed interest rate swapped on the notional amount of $600.0 million of debt that was in effect as of March 31, 2018, 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
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, 2018 and 2017.
 
 
Three months ended March 31,
Costs Included in Interest Expense (in thousands)
 
2018
 
2017
Amortization of deferred financing fees and debt issuance costs and fair market value premiums
 
$
534

 
$
501

Facility fees and unused fees
 
$
339

 
$
275
Schedule of aggregate carrying value of the debt and the corresponding estimate of fair value

The following table presents the aggregate principal outstanding under the Company’s debt arrangements and the corresponding estimate of fair value as of March 31, 2018 and December 31, 2017 (in thousands).
 
 
March 31, 2018
 
December 31, 2017
 
 
Principal Outstanding
 
Fair Value
 
Principal Outstanding
 
Fair Value
Unsecured credit facility
 
$
218,000

 
$
218,371

 
$
271,000

 
$
271,528

Unsecured term loans
 
525,000

 
526,685

 
450,000

 
451,463

Unsecured notes
 
400,000

 
410,058

 
400,000

 
415,599

Mortgage notes
 
58,394

 
58,611

 
58,855

 
59,769

Total principal amount
 
1,201,394

 
$
1,213,725

 
1,179,855

 
$
1,198,359

Add: Total unamortized fair market value premiums
 
58

 
 
 
61

 
 
Less: Total unamortized deferred financing fees and debt issuance costs
 
(5,869
)
 
 
 
(6,135
)
 
 
Total carrying value
 
$
1,195,583

 
 
 
$
1,173,781

 
 
v3.8.0.1
Use of Derivative Financial Instruments (Tables)
 3 Months Ended
Mar. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]  
Schedule of Derivative Instruments [Table Text Block]
The following table details the Company’s outstanding interest rate swaps as of March 31, 2018. All of the Company's interest rate swaps are designated as qualifying cash flow hedges.
Interest Rate
Derivative Counterparty
 
Trade Date    
 
Effective Date
 
Notional Amount
(in thousands)
 
Fair Value
(in thousands)
 
Pay Fixed Interest Rate
 
Receive Variable Interest Rate
 
Maturity Date
Regions Bank
 
Mar-01-2013
 
Mar-01-2013
 
$
25,000

 
$
461

 
1.3300
%
 
One-month L
 
Feb-14-2020 
Capital One, N.A.
 
Jun-13-2013
 
Jul-01-2013
 
$
50,000

 
$
595

 
1.6810
%
 
One-month L
 
Feb-14-2020 
Capital One, N.A.
 
Jun-13-2013
 
Aug-01-2013
 
$
25,000

 
$
287

 
1.7030
%
 
One-month L
 
Feb-14-2020 
Regions Bank
 
Sep-30-2013
 
Feb-03-2014
 
$
25,000

 
$
153

 
1.9925
%
 
One-month L
 
Feb-14-2020 
The Toronto-Dominion Bank
 
Oct-14-2015
 
Sep-29-2016
 
$
25,000

 
$
622

 
1.3830
%
 
One-month L
 
Sep-29-2020
PNC Bank, N.A.
 
Oct-14-2015
 
Sep-29-2016
 
$
50,000

 
$
1,237

 
1.3906
%
 
One-month L
 
Sep-29-2020
Regions Bank
 
Oct-14-2015
 
Sep-29-2016
 
$
35,000

 
$
870

 
1.3858
%
 
One-month L
 
Sep-29-2020
U.S. Bank, N.A.
 
Oct-14-2015
 
Sep-29-2016
 
$
25,000

 
$
618

 
1.3950
%
 
One-month L
 
Sep-29-2020
Capital One, N.A.
 
Oct-14-2015
 
Sep-29-2016
 
$
15,000

 
$
370

 
1.3950
%
 
One-month L
 
Sep-29-2020
Royal Bank of Canada
 
Jan-08-2015
 
Mar-20-2015
 
$
25,000

 
$
529

 
1.7090
%
 
One-month L
 
Mar-21-2021
The Toronto-Dominion Bank
 
Jan-08-2015
 
Mar-20-2015
 
$
25,000

 
$
526

 
1.7105
%
 
One-month L
 
Mar-21-2021
The Toronto-Dominion Bank
 
Jan-08-2015
 
Sep-10-2017
 
$
100,000

 
$
615

 
2.2255
%
 
One-month L
 
Mar-21-2021
Wells Fargo, N.A.
 
Jan-08-2015
 
Mar-20-2015
 
$
25,000

 
$
646

 
1.8280
%
 
One-month L
 
Mar-31-2022
The Toronto-Dominion Bank
 
Jan-08-2015
 
Feb-14-2020
 
$
25,000

 
$
105

 
2.4535
%
 
One-month L
 
Mar-31-2022
Regions Bank
 
Jan-08-2015
 
Feb-14-2020
 
$
50,000

 
$
188

 
2.4750
%
 
One-month L
 
Mar-31-2022
Capital One, N.A.
 
Jan-08-2015
 
Feb-14-2020
 
$
50,000

 
$
135

 
2.5300
%
 
One-month L
 
Mar-31-2022
The Toronto-Dominion Bank
 
Jul-20-2017
 
Oct-30-2017
 
$
25,000

 
$
768

 
1.8485
%
 
One-month L
 
Jan-04-2023
Royal Bank of Canada
 
Jul-20-2017
 
Oct-30-2017
 
$
25,000

 
$
770

 
1.8505
%
 
One-month L
 
Jan-04-2023
Wells Fargo, N.A.
 
Jul-20-2017
 
Oct-30-2017
 
$
25,000

 
$
770

 
1.8505
%
 
One-month L
 
Jan-04-2023
PNC Bank, N.A.
 
Jul-20-2017
 
Oct-30-2017
 
$
25,000

 
$
770

 
1.8485
%
 
One-month L
 
Jan-04-2023
PNC Bank, N.A.
 
Jul-20-2017
 
Oct-30-2017
 
$
50,000

 
$
1,542

 
1.8475
%
 
One-month L
 
Jan-04-2023
Schedule of interest rate swaps
The fair value of the interest rate swaps outstanding as of March 31, 2018 and December 31, 2017 was as follows.
Balance Sheet Line Item (in thousands)
 
Notional Amount March 31, 2018
 
Fair Value
March 31, 2018
 
Notional Amount December 31, 2017
 
Fair Value December 31, 2017
Interest rate swaps-Asset
 
$
725,000

 
$
12,577

 
$
475,000

 
$
6,079

Interest rate swaps-Liability
 
$
—

 
$
—

 
$
250,000

 
$
(1,217
)
Schedule of the location in the financial statements of the gain or loss recognized on interest rate swaps
The table below presents the effect of cash flow hedge accounting and the location in the consolidated financial statements for the three months ended March 31, 2018 and 2017 (in thousands).
 
 
Three months ended March 31,
 
 
2018
 
2017
Income recognized in accumulated other comprehensive income on interest rate swaps
 
$
7,493

 
$
514

Loss reclassified from accumulated other comprehensive income into income (loss) as interest expense
 
$
230

 
$
698

Total interest expense presented in the Consolidated Statements of Operations in which the effects of cash flow hedges are recorded

 
$
11,386

 
$
10,472
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, 2018 and December 31, 2017. 
 
 
 
 
Fair Value Measurements as of
March 31, 2018 Using
Balance Sheet Line Item (in thousands)
 
Fair Value
March 31, 2018
 
Level 1
 
Level 2
 
Level 3
Interest rate swaps-Asset
 
$
12,577

 
$
—

 
$
12,577

 
$
—

Interest rate swaps-Liability
 
$
—

 
$
—

 
$
—

 
$
—


 
 
 
 
Fair Value Measurements as of
December 31, 2017 Using
Balance Sheet Line Item (in thousands)
 
Fair Value December 31, 2017
 
Level 1
 
Level 2
 
Level 3
Interest rate swaps-Asset
 
$
6,079

 
$
—

 
$
6,079

 
$
—

Interest rate swaps-Liability
 
$
(1,217
)
 
$
—

 
$
(1,217
)
 
$
—
v3.8.0.1
Equity (Tables)
 3 Months Ended
Mar. 31, 2018
Stockholders' Equity Note [Abstract]  
Schedule of Stock by Class
The table below sets forth the Company’s outstanding preferred stock issuances as of March 31, 2018.
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
The tables below set forth the dividends attributable to the Company's outstanding preferred stock issuances during the three months ended March 31, 2018 and the year ended December 31, 2017.
Quarter Ended 2018
 
Declaration Date
 
Series B
Preferred Stock Per Share
 
Series C
Preferred Stock Per Share
 
Payment Date
March 31
 
February 14, 2018

0.4140625


0.4296875


April 2, 2018
Total
 
 

$
0.4140625


$
0.4296875


 
Quarter Ended 2017
 
Declaration Date
 
Series B Preferred Stock Per Share
 
Series C Preferred Stock Per Share
 
Payment Date
December 31
 
November 2, 2017
 
$
0.4140625

 
$
0.4296875

 
December 29, 2017
September 30
 
July 31, 2017
 
0.4140625

 
0.4296875

 
September 29, 2017
June 30
 
May 1, 2017
 
0.4140625

 
0.4296875

 
June 30, 2017
March 31
 
February 15, 2017
 
0.4140625

 
0.4296875

 
March 31, 2017
Total
 
 
 
$
1.6562500

 
$
1.7187500

 
 
Dividends

The table below sets forth the dividends attributable to the Company's outstanding shares of common stock that were declared during the three months ended March 31, 2018 and the year ended December 31, 2017.
Month Ended 2018

Declaration Date
 
Record Date
 
Per Share
 
Payment Date
March 31

November 2, 2017

March 29, 2018

0.118333


April 16, 2018
February 28

November 2, 2017

February 28, 2018

0.118333


March 15, 2018
January 31

November 2, 2017

January 31, 2018

0.118333


February 15, 2018
Total

 
 
 

$
0.354999


 
Month Ended 2017
 
Declaration Date
 
Record Date
 
Per Share
 
Payment Date
December 31
 
July 31, 2017
 
December 29, 2017
 
$
0.117500

 
January 16, 2018
November 30
 
July 31, 2017
 
November 30, 2017
 
0.117500

 
December 15, 2017
October 31
 
July 31, 2017
 
October 31, 2017
 
0.117500

 
November 15, 2017
September 30
 
May 1, 2017
 
September 29, 2017
 
0.117500

 
October 16, 2017
August 31
 
May 1, 2017
 
August 31, 2017
 
0.117500

 
September 15, 2017
July 31
 
May 1, 2017
 
July 31, 2017
 
0.117500

 
August 15, 2017
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
 
 
 
 
 
$
1.405002

 
 
Schedule of stock sale activity
The following table sets forth the terms of the Company’s at-the market (“ATM”) common stock offering program as of March 31, 2018.
ATM Common Stock Offering Program
 
Date
 
Maximum Aggregate Offering Price (in thousands)

Aggregate Common Stock Available as of
March 31, 2018 (in thousands)
2017 $500 million ATM
 
November 13, 2017
 
$
500,000

 
$
489,674


The table below set forth the activity under the ATM common stock offering programs during the year ended December 31, 2017 (in thousands, except share data). There was no activity under the ATM common stock offering programs during three months ended March 31, 2018.
 
 
Year ended December 31, 2017
ATM Common Stock Offering Program
 
Shares
Sold
 
Weighted Average Price Per Share
 
Gross
Proceeds
 
Sales
Agents’ Fee
 
Net
Proceeds
2017 $500 million ATM
 
363,843

 
$
28.38

 
$
10,326

 
$
129

 
$
10,197

2017 $300 million ATM(1)
 
11,098,748

 
$
27.03

 
300,000

 
3,637

 
296,363

2016 $228 million ATM(1)
 
4,799,784

 
$
24.42

 
117,216

 
1,604

 
115,612

Total/weighted average
 
16,262,375

 
$
26.29

 
$
427,542

 
$
5,370

 
$
422,172


(1)
These programs ended before December 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, 2018 and the year ended December 31, 2017.
Unvested Restricted Shares of Common Stock
 
Shares
    
Balance at December 31, 2016
 
272,337

 
Granted
 
75,001

(1)
Vested
 
(109,209
)
(2)
Forfeited
 
(922
)
 
Balance at December 31, 2017
 
237,207

 
Granted
 
76,659

(1)
Vested
 
(112,405
)
(2)
Forfeited
 
(5,090
)
 
Balance at March 31, 2018
 
196,371

 
(1)
The fair value per share on the grant date of January 5, 2018 and January 6, 2017 was $26.40 and $24.41, respectively.
(2)
The Company repurchased and retired 41,975 and 40,836 restricted shares of common stock that vested during the three months ended March 31, 2018 and the year ended December 31, 2017, respectively.
Schedule of vested restricted shares of common stock activity
The following table summarizes the fair value at vesting for the restricted shares of common stock that vested during the three months ended March 31, 2018 and 2017. 
 
 
Three months ended March 31,
 
 
2018
 
2017
Vested restricted shares of common stock
 
112,405

 
109,209

Fair value of vested restricted shares of common stock (in thousands)
 
$
3,002

 
$
2,591
v3.8.0.1
Noncontrolling Interest (Tables)
 3 Months Ended
Mar. 31, 2018
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, 2018 and the year ended December 31, 2017.
 
LTIP Units
 
Other
Common Units
 
Total
Noncontrolling Common Units
 
Noncontrolling Interest
Balance at December 31, 2016
1,576,516

 
2,057,365

 
3,633,881

 
4.3
%
Granted/Issued
126,239

 
687,827

 
814,066

 
N/A

Forfeited
—

 
—

 
—

 
N/A

Conversions from LTIP units to Other Common Units
(245,685
)
 
245,685

 
—

 
N/A

Redemptions from Other Common Units to common stock
—

 
(351,260
)
 
(351,260
)
 
N/A

Balance at December 31, 2017
1,457,070

 
2,639,617

 
4,096,687

 
4.1
%
Granted/Issued
324,802

 
—

 
324,802

 
N/A

Forfeited
—

 
—

 
—

 
N/A

Conversions from LTIP units to Other Common Units
(145,672
)
 
145,672

 
—

 
N/A

Redemptions from Other Common Units to common stock
—

 
(145,672
)
 
(145,672
)
 
N/A

Balance at March 31, 2018
1,636,200

 
2,639,617

 
4,275,817

 
4.2
%
Schedule of share-based payment award, LTIP unit awards, valuation assumptions
The table below sets forth the assumptions used in valuing such LTIP units granted during the three months ended March 31, 2018 (excluding those vested LTIP units granted pursuant to the 2015 OPP; refer to Note 8 for details).
LTIP Units
 
Assumptions
Grant date
 
March 12, 2018

 
January 5, 2018

Expected term (years)
 
10

 
10

Expected volatility
 
22.0
%
 
22.0
%
Expected dividend yield
 
6.0
%
 
6.0
%
Risk-free interest rate
 
2.46
%
 
2.09
%
Fair value of LTIP units at issuance (in thousands)
 
$
90

 
$
3,447

LTIP units at issuance
 
3,930

 
137,616

Fair value unit price per LTIP unit at issuance
 
$
22.90

 
$
25.05
Schedule of activity related to unvested LTIP unit awards
The following table summarizes activity related to the Company’s unvested LTIP units for the three months ended March 31, 2018 and the year ended December 31, 2017.
Unvested LTIP Units
 
LTIP Units
Balance at December 31, 2016
 
403,423

Granted
 
126,239

Vested
 
(229,355
)
Forfeited
 
—

Balance at December 31, 2017
 
300,307

Granted
 
324,802

Vested
 
(231,041
)
Forfeited
 
—

Balance at March 31, 2018
 
394,068
Schedule of vested LTIP unit award activity
The following table summarizes the fair value at vesting for the LTIP units that vested during the three months ended March 31, 2018 and 2017.
 
 
Three months ended March 31,
 
 
2018
 
2017
Vested LTIP units
 
231,041

 
67,670

Fair value of vested LTIP units (in thousands)
 
$
6,035

 
$
1,664
v3.8.0.1
Equity Incentive Plan (Tables)
 3 Months Ended
Mar. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]  
Schedule of share-based payment award, performance unit awards, valuation assumptions
The table below sets forth the assumptions used in valuing the performance units granted during the three months ended March 31, 2018.
Performance Units
 
Assumptions
Grant date
 
January 5, 2018

Expected volatility
 
22.0
%
Expected dividend yield
 
6.0
%
Risk-free interest rate
 
2.09
%
Fair value of performance units grant (in thousands)
 
$
5,456
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 units, the 2015 OPP (performance units and the 2015 OPP, collectively the “Performance-based Compensation Plans”), and the Company’s director compensation for the three months ended March 31, 2018 and 2017.
 
 
Three months ended March 31,
Non-Cash Compensation Expense (in thousands)
 
2018
    
2017
Restricted shares of common stock
 
$
434

  
$
592

LTIP units
 
871

 
1,170

Performance-based Compensation Plans
 
829

 
537

Director compensation (1)
 
86

 
88

Total non-cash compensation expense
 
$
2,220

 
$
2,387

(1)
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, 2018 and 2017. 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.
v3.8.0.1
Earnings Per Share (Tables)
 3 Months Ended
Mar. 31, 2018
Earnings Per Share [Abstract]  
Schedule of computation of basic and diluted earnings per common share
The following table sets forth the computation of basic and diluted earnings per common share for the three months ended March 31, 2018 and 2017.
 
Three months ended March 31,
Earnings Per Share (in thousands, except per share data)
2018
 
2017
Numerator
 
 
 
Net income
$
25,149

 
$
69

Less: preferred stock dividends
2,448

 
2,448

Less: amount allocated to participating securities
71

 
83

Less: income (loss) attributable to noncontrolling interest after preferred stock dividends
954

 
(103
)
Net income (loss) attributable to common stockholders
$
21,676


$
(2,359
)
Denominator
 

 
 
Weighted average common shares outstanding — basic
97,021

 
81,808

Effect of dilutive securities(1)
 
 
 
Share-based compensation
302

 
—

Weighted average common shares outstanding — diluted
97,323

 
81,808

Net income (loss) per share — basic and diluted
 
 
 
Net income (loss) per share attributable to common stockholders — basic
$
0.22

 
$
(0.03
)
Net income (loss) per share attributable to common stockholders — diluted
$
0.22

 
$
(0.03
)
(1)
During the three months ended March 31, 2018 and 2017, there were approximately 202 and 240, respectively, unvested restricted shares of common stock, respectively, 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. During the three months ended March 31, 2017, there were approximately 438 unvested shares under the Performance-based Compensation Plans 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.
v3.8.0.1
Organization and Description of Business (Details)
ft² in Millions
 3 Months Ended 12 Months Ended
Mar. 31, 2018
ft²
tenant
state
building
Dec. 31, 2017
Real Estate Properties [Line Items]    
Ownership interest in Operating Partnership (as a percent) 95.80% 95.90%
Number of properties 360  
Number of states in which the entity owned buildings | state 37  
Area (in square feet) | ft² 70.8  
Percentage of buildings leased to tenants 94.70%  
Number of tenants | tenant 312  
Warehouse - Distribution buildings    
Real Estate Properties [Line Items]    
Number of properties 291  
Light Manufacturing buildings    
Real Estate Properties [Line Items]    
Number of properties 55  
Flex/Office Buildings    
Real Estate Properties [Line Items]    
Number of properties 14  
v3.8.0.1
Summary of Significant Accounting Policies - New Accounting Pronouncements (Details) - USD ($)
$ in Thousands
 3 Months Ended
Mar. 31, 2018
Mar. 31, 2017
Jan. 01, 2018
Dec. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]        
Increase to accumulated other comprehensive income (loss) $ 11,581     $ 3,936
Increase in cash provided by operating activities 41,974 $ 31,408    
Increase in cash used in investing activities $ 36,112 102,089    
Accounting Standards Update 2016-18 [Member]        
New Accounting Pronouncements or Change in Accounting Principle [Line Items]        
Increase in cash provided by operating activities   300    
Increase in cash used in investing activities   $ (1,100)    
New Accounting Pronouncement, Early Adoption, Effect [Member] | Accounting Standards Update 2017-12 [Member]        
New Accounting Pronouncements or Change in Accounting Principle [Line Items]        
Increase to accumulated other comprehensive income (loss)     $ 300  
Decrease in accumulated distributions in excess of net income     $ 300  
v3.8.0.1
Summary of Significant Accounting Policies - Restricted Cash (Details) - USD ($)
$ in Thousands
Mar. 31, 2018
Dec. 31, 2017
Mar. 31, 2017
Accounting Policies [Abstract]      
Cash and cash equivalents $ 10,455 $ 24,562 $ 7,082
Restricted cash 7,259 $ 3,567 8,720
Cash and cash equivalents and restricted cash—end of period $ 17,714   $ 15,802
v3.8.0.1
Summary of Significant Accounting Policies - Tenant Accounts Receivable (Details) - USD ($)
Mar. 31, 2018
Dec. 31, 2017
Tenant Accounts Receivable, net    
Lease security deposits available in existing letters of credit $ 12,700,000 $ 12,700,000
Cash and Cash Equivalents    
Tenant Accounts Receivable, net    
Security deposit 7,700,000 7,400,000
Restricted Cash    
Tenant Accounts Receivable, net    
Security deposit 700,000 700,000
Security Deposits    
Tenant Accounts Receivable, net    
Lease security deposits available in cash 8,400,000 8,100,000
Prepaid Expenses and Other Assets    
Tenant Accounts Receivable, net    
Due from related parties 4,000 0
Trade Accounts Receivable    
Tenant Accounts Receivable, net    
Allowance for doubtful accounts 100,000 100,000
Accrued Income Receivable    
Tenant Accounts Receivable, net    
Allowance for doubtful accounts 100,000 200,000
Deferred Rent Receivables, Net $ 25,900,000 $ 24,700,000
v3.8.0.1
Summary of Significant Accounting Policies - Revenue Recognition (Details) - USD ($)
 3 Months Ended
Mar. 31, 2018
Mar. 31, 2017
Revenue Recognition    
Estimated amount of real estate taxes, which are the responsibility of tenants $ 3,100,000 $ 3,100,000
Buena Vista, VA, Q3 2012 | Rental income    
Revenue Recognition    
Gain (Loss) on Contract Termination $ 100,000 $ 39,000
v3.8.0.1
Summary of Significant Accounting Policies - Taxes (Details) - USD ($)
 3 Months Ended
Mar. 31, 2018
Mar. 31, 2017
Dec. 31, 2017
Business Acquisition [Line Items]      
Net income $ 25,149,000 $ 69,000  
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 $ (36,000) $ (31,000)  
v3.8.0.1
Rental Property - Summary (Details) - USD ($)
$ in Thousands
Mar. 31, 2018
Dec. 31, 2017
Property Subject to or Available for Operating Lease [Line Items]    
Rental property, net $ 2,588,354 $ 2,567,577
Deferred leasing intangibles assets, accumulated amortization 215,597 280,642
Land    
Property Subject to or Available for Operating Lease [Line Items]    
Rental property, net 324,734 321,560
Buildings, net of accumulated depreciation of $160,281 and $160,281, respectively    
Property Subject to or Available for Operating Lease [Line Items]    
Rental property, net 1,784,897 1,756,579
Rental property, accumulated depreciation 171,058 160,281
Tenant improvements, net of accumulated depreciation of $32,714 and $32,714, respectively    
Property Subject to or Available for Operating Lease [Line Items]    
Rental property, net 29,648 30,138
Rental property, accumulated depreciation 33,669 32,714
Building and land improvements, net of accumulated depreciation of $56,062 and $56,062, respectively    
Property Subject to or Available for Operating Lease [Line Items]    
Rental property, net 141,936 143,170
Rental property, accumulated depreciation 61,431 56,062
Construction in progress    
Property Subject to or Available for Operating Lease [Line Items]    
Rental property, net 1,951 2,877
Deferred leasing intangibles, net of accumulated amortization of $280,642 and $280,642, respectively    
Property Subject to or Available for Operating Lease [Line Items]    
Rental property, net 305,188 313,253
Deferred leasing intangibles assets, accumulated amortization $ 215,597 $ 280,642
v3.8.0.1
Rental Property - Acquisitions (Details)
$ in Thousands
 3 Months Ended
Mar. 31, 2018
USD ($)
ft²
building
Business Acquisition [Line Items]  
Area (in square feet) 70,800,000
Acquisitions 2018 [Member]  
Business Acquisition [Line Items]  
Area (in square feet) 1,091,868
Number of Buildings Acquired | building 6
Business Combination, Consideration Transferred | $ $ 78,821
Fountain Inn, SC, Q1 2018 [Member]  
Business Acquisition [Line Items]  
Area (in square feet) 203,000
Number of Buildings Acquired | building 1
Business Combination, Consideration Transferred | $ $ 10,755
Bloomington, MN, Q1 2018 [Member]  
Business Acquisition [Line Items]  
Area (in square feet) 145,351
Number of Buildings Acquired | building 1
Business Combination, Consideration Transferred | $ $ 13,538
York, PA, Q1 2018 [Member]  
Business Acquisition [Line Items]  
Area (in square feet) 278,582
Number of Buildings Acquired | building 1
Business Combination, Consideration Transferred | $ $ 18,277
Houston, TX, Q1 2018 [Member]  
Business Acquisition [Line Items]  
Area (in square feet) 242,225
Number of Buildings Acquired | building 2
Business Combination, Consideration Transferred | $ $ 22,478
Greer, SC, Q1 2018 [Member]  
Business Acquisition [Line Items]  
Area (in square feet) 222,710
Number of Buildings Acquired | building 1
Business Combination, Consideration Transferred | $ $ 13,773
v3.8.0.1
Rental Property - Acquisitions - Allocation of Consideration (Details) - Acquisitions 2018 [Member]
$ in Thousands
 3 Months Ended
Mar. 31, 2018
USD ($)
Allocation of the consideration paid for the acquired assets and liabilities  
Land $ 6,415
Buildings 57,248
Tenant improvements 996
Building and land improvements 2,418
Deferred leasing intangibles - Below market leases $ (673)
Weighted average amortization period of below market leases 9 years 7 months 25 days
Total purchase price $ 78,821
In-place leases  
Allocation of the consideration paid for the acquired assets and liabilities  
Deferred leasing intangibles $ 8,122
Weighted average amortization period of lease intangibles 6 years 3 months
Tenant relationships  
Allocation of the consideration paid for the acquired assets and liabilities  
Deferred leasing intangibles $ 3,712
Weighted average amortization period of lease intangibles 10 years 5 months 15 days
Above market leases  
Allocation of the consideration paid for the acquired assets and liabilities  
Deferred leasing intangibles $ 583
Weighted average amortization period of lease intangibles 5 years 8 months 31 days
v3.8.0.1
Rental Property - Acquisitions - Results of Operations (Details) - Acquisitions 2018 [Member]
$ in Thousands
 3 Months Ended
Mar. 31, 2018
USD ($)
Business Acquisition [Line Items]  
Revenue $ 924
Net income (loss) $ 104
v3.8.0.1
Rental Property - Disposals (Details)
ft² in Millions
 3 Months Ended
Mar. 31, 2018
USD ($)
ft²
building
Mar. 31, 2017
USD ($)
Dec. 31, 2017
USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]      
Number of buildings disposed | building 360    
Area (in square feet) | ft² 70.8    
Carrying value of property sold $ 2,588,354,000   $ 2,567,577,000
Disposal Group, Disposed of by Sale, Not Discontinued Operations | 2018 Disposals [Member]      
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]      
Number of buildings disposed | building 2    
Area (in square feet) | ft² 0.7    
Carrying value of property sold $ 26,900,000    
Net proceeds from sales of rental property 49,600,000    
Gain (Loss) on Sale 22,700,000    
Contribution to revenue 300,000 $ 900,000  
Amount contributed to net income (loss) before gain on sale of rental property $ 49,000 $ 46,000  
v3.8.0.1
Rental Property - Held for Sale (Details)
 3 Months Ended
Mar. 31, 2018
USD ($)
property
building
Mar. 31, 2017
USD ($)
Dec. 31, 2017
USD ($)
Long Lived Assets Held-for-sale [Line Items]      
Number of properties | building 360    
Assets held for sale, net $ 13,498,000   $ 19,916,000
Intangible Assets, Net (Excluding Goodwill) $ 305,188,000   $ 313,253,000
Disposal Group, Held-for-sale, Not Discontinued Operations [Member]      
Long Lived Assets Held-for-sale [Line Items]      
Number of properties | property 2    
Intangible Assets, Net (Excluding Goodwill) $ 800,000    
Contribution to revenue 200,000 $ 500,000  
Amount contributed to net income (loss) (800,000) $ (29,000)  
Disposal Group, Held-for-sale, Not Discontinued Operations [Member] | Land [Member]      
Long Lived Assets Held-for-sale [Line Items]      
Assets held for sale, net 2,000,000    
Disposal Group, Held-for-sale, Not Discontinued Operations [Member] | Building and Building Improvements [Member]      
Long Lived Assets Held-for-sale [Line Items]      
Assets held for sale, net $ 10,700,000    
v3.8.0.1
Rental Property - Loss on Impairments (Details)
$ in Thousands
 3 Months Ended
Mar. 31, 2018
USD ($)
building
Rate
2018 Impairments [Member]  
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]  
Loss on Impairment | $ $ 2,934
2018 Impairments [Member] | Income Approach Valuation Technique | Fair Value, Inputs, Level 3  
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]  
Fair Value Disclosure | $ $ 3,176
2018 Impairments [Member] | Income Approach Valuation Technique | Minimum | Fair Value, Inputs, Level 3  
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]  
Fair Value Inputs, Discount Rate 11.00%
Fair Value Inputs Exit Capitalization Rate 11.00%
2018 Impairments [Member] | Income Approach Valuation Technique | Maximum | Fair Value, Inputs, Level 3  
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]  
Fair Value Inputs, Discount Rate 14.50%
Fair Value Inputs Exit Capitalization Rate 13.00%
Buena Vista, VA, Q3 2012  
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]  
Number of Buildings Impaired | building 1
Sergeant Bluff, IA, Q4 2007  
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]  
Number of Buildings Impaired | building 1
v3.8.0.1
Rental Property - Deferred Leasing Intangibles (Details) - USD ($)
$ in Thousands
 3 Months Ended
Mar. 31, 2018
Mar. 31, 2017
Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]      
Above market lease, gross $ 520,785   $ 593,895
Deferred leasing intangibles assets, accumulated amortization (215,597)   (280,642)
Above market lease, net 305,188   313,253
Below market lease, gross 32,041   34,776
Below market lease, accumulated amortization (11,321)   (13,555)
Below market lease, net 20,720   21,221
Above market leases      
Finite-Lived Intangible Assets [Line Items]      
Above market lease, gross 70,675   78,558
Deferred leasing intangibles assets, accumulated amortization (30,725)   (36,810)
Above market lease, net 39,950   41,748
Net decrease to rental income related to above and below market lease amortization      
Finite-Lived Intangible Assets [Line Items]      
Net decrease to rental revenue related to above and below market lease amortization 1,207 $ 1,296  
Estimated Net Amortization of In-Place Leases, Leasing Commissions and Tenant Relationships      
Remainder of 2018 2,987    
2019 3,846    
2020 3,504    
2021 2,178    
2022 1,210    
Other intangible lease assets      
Finite-Lived Intangible Assets [Line Items]      
Above market lease, gross 450,110   515,337
Deferred leasing intangibles assets, accumulated amortization (184,872)   (243,832)
Above market lease, net 265,238   $ 271,505
Amortization expense related to other intangible lease assets 18,100 $ 18,393  
Estimated Net Amortization of In-Place Leases, Leasing Commissions and Tenant Relationships      
Remainder of 2018 48,805    
2019 50,905    
2020 40,954    
2021 30,242    
2022 $ 23,113    
v3.8.0.1
Debt - Summary (Details) - USD ($)
$ in Thousands
 3 Months Ended 12 Months Ended
Mar. 31, 2018
Dec. 31, 2017
Debt Instrument [Line Items]    
Long-term debt, gross $ 1,201,394 $ 1,179,855
Unamortized debt issuance costs (5,869) (6,135)
Debt Instrument, Unused Borrowing Capacity, Amount 301,100  
Unamortized fair market value premium 58 61
Principal outstanding $ 1,195,583 1,173,781
Weighted average interest rate 3.56%  
Interest Rate Swaps    
Debt Instrument [Line Items]    
Notional amount $ 600,000  
One Month LIBOR    
Debt Instrument [Line Items]    
Variable rate basis reference rate (as a percent) 1.88313%  
$150 Million Unsecured Term Loan D [Member]    
Debt Instrument [Line Items]    
Debt Instrument, Unused Borrowing Capacity, Amount $ 75,000  
Mortgage Loans Payable    
Debt Instrument [Line Items]    
Long-term debt, gross 58,394 58,855
Unamortized debt issuance costs (601) (634)
Unamortized fair market value premium 58 61
Principal outstanding 57,851 58,282
Mortgage Loans Payable | Wells Fargo Bank, National Association CMBS Loan    
Debt Instrument [Line Items]    
Long-term debt, gross $ 54,515 54,949
Stated interest rate 4.31%  
Penalty free prepayment period 3 months  
Mortgage Loans Payable | Thrivent Financial for Lutherans Due December 15, 2023 [Member]    
Debt Instrument [Line Items]    
Long-term debt, gross $ 3,879 3,906
Stated interest rate 4.78%  
Penalty free prepayment period 3 months  
Unsecured Term Loans    
Debt Instrument [Line Items]    
Long-term debt, gross $ 525,000 450,000
Unsecured Term Loans | Term Loan    
Debt Instrument [Line Items]    
Long-term debt, gross 525,000 450,000
Unamortized debt issuance costs (3,494) (3,735)
Principal outstanding 521,506 446,265
Unsecured Term Loans | $150 Million Wells Fargo Unsecured Term Loan C    
Debt Instrument [Line Items]    
Long-term debt, gross $ 150,000 $ 150,000
Interest rate margin (as a percent) 1.30% 1.30%
Unsecured Term Loans | $150 Million Wells Fargo Unsecured Term Loan B    
Debt Instrument [Line Items]    
Long-term debt, gross $ 150,000 $ 150,000
Interest rate margin (as a percent) 1.30% 1.30%
Unsecured Term Loans | $150 Million Wells Fargo Unsecured Term Loan A    
Debt Instrument [Line Items]    
Long-term debt, gross $ 150,000 $ 150,000
Interest rate margin (as a percent) 1.30% 1.30%
Unsecured Term Loans | $150 Million Unsecured Term Loan D [Member]    
Debt Instrument [Line Items]    
Long-term debt, gross $ 75,000 $ 0
Interest rate margin (as a percent) 1.30% 1.30%
Unsecured Notes    
Debt Instrument [Line Items]    
Long-term debt, gross $ 400,000 $ 400,000
Unsecured Notes | Unsecured Notes    
Debt Instrument [Line Items]    
Long-term debt, gross 400,000 400,000
Unamortized debt issuance costs (1,774) (1,766)
Principal outstanding 398,226 398,234
Unsecured Notes | $100 Million Series F Unsecured Notes    
Debt Instrument [Line Items]    
Long-term debt, gross $ 100,000 100,000
Stated interest rate 3.98%  
Unsecured Notes | $50 Million Series A Unsecured Notes    
Debt Instrument [Line Items]    
Long-term debt, gross $ 50,000 50,000
Stated interest rate 4.98%  
Unsecured Notes | $100 Million Series D Unsecured Notes    
Debt Instrument [Line Items]    
Long-term debt, gross $ 100,000 100,000
Stated interest rate 4.32%  
Unsecured Notes | $50 Million Series B Unsecured Notes    
Debt Instrument [Line Items]    
Long-term debt, gross $ 50,000 50,000
Stated interest rate 4.98%  
Unsecured Notes | $80 Million Series C Unsecured Notes    
Debt Instrument [Line Items]    
Long-term debt, gross $ 80,000 80,000
Stated interest rate 4.42%  
Unsecured Notes | $20 Million Series E Unsecured Notes    
Debt Instrument [Line Items]    
Long-term debt, gross $ 20,000 20,000
Stated interest rate 4.42%  
Unsecured Credit Facility    
Debt Instrument [Line Items]    
Principal outstanding $ 218,000 $ 271,000
Interest rate margin (as a percent) 1.15% 1.15%
Maximum borrowing capacity $ 450,000  
Unsecured Credit Facility | Prepaid Expenses and Other Assets    
Debt Instrument [Line Items]    
Unamortized debt issuance costs $ (1,300) $ (1,500)
v3.8.0.1
Debt - 2018 Activity (Details) - USD ($)
$ in Thousands
 3 Months Ended
Mar. 28, 2018
Mar. 31, 2018
Mar. 31, 2017
Dec. 31, 2017
Debt Instrument [Line Items]        
Debt Instrument, Unused Borrowing Capacity, Amount   $ 301,100    
Amortization of deferred financing fees   534 $ 501  
Net book value of properties that are collateral for debt arrangements   89,800   $ 90,900
Accounts Payable, Accrued Expenses and Other Liabilities        
Debt Instrument [Line Items]        
Interest payable   5,400   $ 5,600
$150 Million Unsecured Term Loan D [Member]        
Debt Instrument [Line Items]        
Debt Instrument, Unused Borrowing Capacity, Amount   75,000    
$150 Million Unsecured Term Loan D [Member] | Unsecured Term Loans        
Debt Instrument [Line Items]        
Proceeds from Issuance of Debt $ 75,000      
Interest Expense [Member] | Unsecured Credit Facility        
Debt Instrument [Line Items]        
Line of Credit Facility, Commitment Fee Amount   $ 339 $ 275  
v3.8.0.1
Debt - Fair Value (Details) - USD ($)
$ in Thousands
Mar. 31, 2018
Dec. 31, 2017
Debt Instrument [Line Items]    
Long-term debt, gross $ 1,201,394 $ 1,179,855
Unamortized fair market value premium 58 61
Unamortized debt issuance costs (5,869) (6,135)
Principal outstanding 1,195,583 1,173,781
Long-term debt, fair value 1,213,725 1,198,359
Unsecured Term Loans    
Debt Instrument [Line Items]    
Long-term debt, gross 525,000 450,000
Long-term debt, fair value 526,685 451,463
Unsecured Credit Facility    
Debt Instrument [Line Items]    
Principal outstanding 218,000 271,000
Long-term debt, fair value 218,371 271,528
Unsecured Notes    
Debt Instrument [Line Items]    
Long-term debt, gross 400,000 400,000
Long-term debt, fair value 410,058 415,599
Mortgage Loans Payable    
Debt Instrument [Line Items]    
Long-term debt, gross 58,394 58,855
Unamortized fair market value premium 58 61
Unamortized debt issuance costs (601) (634)
Principal outstanding 57,851 58,282
Long-term debt, fair value $ 58,611 $ 59,769
v3.8.0.1
Use of Derivative Financial Instruments - Risk Management and Unsecured Loan Swaps (Details)
$ in Thousands
Mar. 31, 2018
USD ($)
Interest Rate Swaps  
Unsecured Term Loan Swaps  
Notional amount $ 600,000
Interest Rate Derivative, Regions Bank, March 01, 2013  
Unsecured Term Loan Swaps  
Notional amount 25,000
Fair value $ 461
Fixed Interest Rate (as a percent) 1.33%
Interest Rate Derivative, Capital One, July 01, 2013  
Unsecured Term Loan Swaps  
Notional amount $ 50,000
Fair value $ 595
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 $ 287
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 $ 153
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 $ 622
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 $ 1,237
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 $ 870
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 $ 618
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 $ 370
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 $ 529
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 $ 526
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 $ 615
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 $ 646
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 $ 105
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 $ 188
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 $ 135
Fixed Interest Rate (as a percent) 2.53%
Interest Rate Derivative, The Toronto-Dominion Bank, October 30, 2017  
Unsecured Term Loan Swaps  
Notional amount $ 25,000
Fair value $ 768
Fixed Interest Rate (as a percent) 1.8485%
Interest Rate Derivative, Royal Bank of Canada, October 30, 2017  
Unsecured Term Loan Swaps  
Notional amount $ 25,000
Fair value $ 770
Fixed Interest Rate (as a percent) 1.8505%
Interest Rate Derivative, Wells Fargo Bank, October 30, 2017  
Unsecured Term Loan Swaps  
Notional amount $ 25,000
Fair value $ 770
Fixed Interest Rate (as a percent) 1.8505%
Interest Rate Derivative, PNC Bank, $25m, October 30, 2017  
Unsecured Term Loan Swaps  
Notional amount $ 25,000
Fair value $ 770
Fixed Interest Rate (as a percent) 1.8485%
Interest Rate Derivative, PNC Bank, $50m, October 30, 2017  
Unsecured Term Loan Swaps  
Notional amount $ 50,000
Fair value $ 1,542
Fixed Interest Rate (as a percent) 1.8475%
v3.8.0.1
Use of Derivative Financial Instruments - FV of Interest Rate Swaps (Details) - Interest Rate Swaps - USD ($)
$ in Thousands
Mar. 31, 2018
Dec. 31, 2017
Fair value of the interest rate swaps outstanding    
Notional amount assets $ 725,000 $ 475,000
Fair value - assets 12,577 6,079
Notional amount liabilities 0 250,000
Fair Value - liabilities $ 0 $ (1,217)
v3.8.0.1
Use of Derivative Financial Instruments - Cash Flow Hedges and Contingent Features (Details) - USD ($)
$ in Thousands
 3 Months Ended
Mar. 31, 2018
Mar. 31, 2017
Cash Flow Hedges of Interest Rate Risk    
Total interest expense presented in the Consolidated Statements of Operations in which the effects of cash flow hedges are recorded $ 11,386 $ 10,472
Interest Rate Swaps    
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 2,300  
Income recognized in accumulated other comprehensive income on interest rate swaps 7,493 514
Loss reclassified from accumulated other comprehensive income into income (loss) as interest expense 230 698
Total interest expense presented in the Consolidated Statements of Operations in which the effects of cash flow hedges are recorded $ 11,386 $ 10,472
v3.8.0.1
Use of Derivative Financial Instruments - FV on Recurring Basis (Details) - Interest Rate Swaps - Fair value on recurring basis - USD ($)
$ in Thousands
Mar. 31, 2018
Dec. 31, 2017
Assets (liabilities):    
Interest rate swaps-Asset $ 12,577 $ 6,079
Interest rate swaps-Liability 0 (1,217)
Level 1    
Assets (liabilities):    
Interest rate swaps-Asset 0 0
Interest rate swaps-Liability 0 0
Level 2    
Assets (liabilities):    
Interest rate swaps-Asset 12,577 6,079
Interest rate swaps-Liability 0 (1,217)
Level 3    
Assets (liabilities):    
Interest rate swaps-Asset 0 0
Interest rate swaps-Liability $ 0 $ 0
v3.8.0.1
Equity - Preferred Stock (Details) - $ / shares
 3 Months Ended 12 Months Ended
Apr. 10, 2018
Apr. 02, 2018
Feb. 14, 2018
Dec. 29, 2017
Nov. 02, 2017
Sep. 29, 2017
Jul. 31, 2017
Jun. 30, 2017
May 01, 2017
Mar. 31, 2017
Feb. 15, 2017
Mar. 31, 2018
Dec. 31, 2017
Class of Stock [Line Items]                          
Preferred stock, shares authorized                       15,000,000 15,000,000
Preferred stock, par value (in dollars per share)                       $ 0.01 $ 0.01
Series B Preferred Stock                          
Class of Stock [Line Items]                          
Number of shares sold                       2,800,000  
Preferred stock, liquidation preference (in dollars per share)                       $ 25.00 25.00
Dividend rate (as a percent)                       6.625%  
Preferred Stock, Dividends Per Share, Declared     $ 0.4140625   $ 0.4140625   $ 0.4140625   $ 0.4140625   $ 0.4140625 $ 0.4140625 1.6562500
Preferred Stock, Dividends, Per Share, Cash Paid       $ 0.4140625   $ 0.4140625   $ 0.4140625   $ 0.4140625   $ 0.4140625 1.6562500
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]                          
Number of shares sold                       3,000,000  
Preferred stock, liquidation preference (in dollars per share)                       $ 25.00 25.00
Dividend rate (as a percent)                       6.875%  
Preferred Stock, Dividends Per Share, Declared     $ 0.4296875   $ 0.4296875   $ 0.4296875   $ 0.4296875   $ 0.4296875 $ 0.4296875 1.7187500
Preferred Stock, Dividends, Per Share, Cash Paid       $ 0.4296875   $ 0.4296875   $ 0.4296875   $ 0.4296875   $ 0.4296875 $ 1.7187500
Series C Preferred Stock | Non-recognized Subsequent Event                          
Class of Stock [Line Items]                          
Preferred Stock, Dividends Per Share, Declared $ 0.4296875                        
Scenario, Forecast [Member] | Series B Preferred Stock                          
Class of Stock [Line Items]                          
Preferred Stock, Dividends, Per Share, Cash Paid   $ 0.4140625                      
Scenario, Forecast [Member] | Series C Preferred Stock                          
Class of Stock [Line Items]                          
Preferred Stock, Dividends, Per Share, Cash Paid   $ 0.4296875                      
v3.8.0.1
Equity - Common Stock ATM (Details) - USD ($)
$ / shares in Units, $ in Thousands
 3 Months Ended 12 Months Ended
Mar. 31, 2018
Mar. 31, 2017
Dec. 31, 2017
Class of Stock [Line Items]      
Proceeds from sales of common stock $ 0 $ 68,543  
At The Market Program 2017 $500 Million | Common Stock      
Class of Stock [Line Items]      
Common Stock Value Authorized under Stock Offering Program 500,000    
Aggregate value of common stock available to be sold under the ATM $ 489,674    
Number of shares sold     363,843
Proceeds from sales of common stock     $ 10,326
Sales agents' fee     129
Net proceeds     $ 10,197
At The Market Program 2017 $300 Million | Common Stock      
Class of Stock [Line Items]      
Number of shares sold     11,098,748
Proceeds from sales of common stock     $ 300,000
Sales agents' fee     3,637
Net proceeds     $ 296,363
At The Market Program 2016 $228 Million | Common Stock      
Class of Stock [Line Items]      
Number of shares sold     4,799,784
Proceeds from sales of common stock     $ 117,216
Sales agents' fee     1,604
Net proceeds     $ 115,612
At The Market (ATM) Program | Common Stock      
Class of Stock [Line Items]      
Number of shares sold     16,262,375
Proceeds from sales of common stock     $ 427,542
Sales agents' fee     5,370
Net proceeds     $ 422,172
Weighted Average | At The Market Program 2017 $500 Million | Common Stock      
Class of Stock [Line Items]      
Issue price (in dollars per share)     $ 28.38
Weighted Average | At The Market Program 2017 $300 Million | Common Stock      
Class of Stock [Line Items]      
Issue price (in dollars per share)     27.03
Weighted Average | At The Market Program 2016 $228 Million | Common Stock      
Class of Stock [Line Items]      
Issue price (in dollars per share)     24.42
Weighted Average | At The Market (ATM) Program | Common Stock      
Class of Stock [Line Items]      
Issue price (in dollars per share)     $ 26.29
v3.8.0.1
Equity - Common Stock Dividends (Details) - Common Stock - $ / shares
 3 Months Ended 12 Months Ended
Apr. 16, 2018
Apr. 10, 2018
Mar. 15, 2018
Feb. 15, 2018
Jan. 16, 2018
Dec. 15, 2017
Nov. 15, 2017
Nov. 02, 2017
Oct. 16, 2017
Sep. 15, 2017
Aug. 15, 2017
Jul. 31, 2017
Jul. 17, 2017
Jun. 15, 2017
May 15, 2017
May 01, 2017
Apr. 17, 2017
Mar. 15, 2017
Feb. 15, 2017
Nov. 02, 2016
Mar. 31, 2018
Dec. 31, 2017
Class of Stock [Line Items]                                            
Common Stock, Dividends, Per Share, Cash Paid     $ 0.118333 $ 0.118333 $ 0.117500 $ 0.117500 $ 0.117500   $ 0.117500 $ 0.117500 $ 0.117500   $ 0.116667 $ 0.116667 $ 0.116667   $ 0.116667 $ 0.116667 $ 0.116667   $ 0.354999 $ 1.405002
Common Stock, Dividends, Per Share, Declared               $ 0.118333       $ 0.117500       $ 0.117500     $ 0.116667 $ 0.116667 $ 0.354999 $ 1.405002
Scenario, Forecast [Member]                                            
Class of Stock [Line Items]                                            
Common Stock, Dividends, Per Share, Cash Paid $ 0.118333                                          
Non-recognized Subsequent Event                                            
Class of Stock [Line Items]                                            
Common Stock, Dividends, Per Share, Declared   $ 0.118333                                        
v3.8.0.1
Equity - Restricted Stock (Details) - Restricted stock - USD ($)
$ / shares in Units, $ in Thousands
 3 Months Ended 12 Months Ended
Mar. 31, 2018
Mar. 31, 2017
Dec. 31, 2017
Shares      
Unvested at beginning of period (in shares) 237,207 272,337 272,337
Granted (in shares) 76,659   75,001
Vested (in shares) (112,405) (109,209) (109,209)
Forfeited (in shares) (5,090)   (922)
Unvested at end of period (in shares) 196,371   237,207
Grant date fair value (in dollars per share) $ 26.40   $ 24.41
Stock Repurchased and Retired During Period, Shares 41,975   40,836
Unrecognized compensation costs $ 4,100    
Unrecognized compensation costs, period for recognition 2 years 10 months 10 days    
Vested (in shares) (112,405) (109,209) (109,209)
Fair value of shares vested $ 3,002 $ 2,591  
Granted on January 5, 2018      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Vesting period (in years) 4 years    
v3.8.0.1
Noncontrolling Interest - Summary (Details) - shares
 3 Months Ended 12 Months Ended
Mar. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Noncontrolling interest      
Noncontrolling interest ownership percentage 4.20% 4.10% 4.30%
Noncontrolling Interest - Unit holders in Operating Partnership      
Noncontrolling interest      
Units outstanding, balance at beginning of period (in units) 4,096,687 3,633,881  
Granted/Issued (in units) 324,802 814,066  
Forfeitures (in units) 0 0  
Limited Partners' Capital Account, Units, Converted 0 0  
Redemptions from Other Common Units to common stock (in units) (145,672) (351,260)  
Units outstanding, balance at end of period (in units) 4,275,817 4,096,687  
LTIP Units | Noncontrolling Interest - Unit holders in Operating Partnership      
Noncontrolling interest      
Units outstanding, balance at beginning of period (in units) 1,457,070 1,576,516  
Granted/Issued (in units) 324,802 126,239  
Forfeitures (in units) 0 0  
Limited Partners' Capital Account, Units, Converted 145,672 245,685  
Redemptions from Other Common Units to common stock (in units) 0 0  
Units outstanding, balance at end of period (in units) 1,636,200 1,457,070  
Other Common Units | Noncontrolling Interest - Unit holders in Operating Partnership      
Noncontrolling interest      
Units outstanding, balance at beginning of period (in units) 2,639,617 2,057,365  
Granted/Issued (in units) 0 687,827  
Forfeitures (in units) 0 0  
Limited Partners' Capital Account, Units, Converted (145,672) (245,685)  
Redemptions from Other Common Units to common stock (in units) (145,672) (351,260)  
Units outstanding, balance at end of period (in units) 2,639,617 2,639,617  
v3.8.0.1
Noncontrolling Interest - LTIP FV Assumptions (Details) - LTIP Units - USD ($)
$ / shares in Units, $ in Thousands
 3 Months Ended 12 Months Ended
Mar. 12, 2018
Jan. 05, 2018
Mar. 31, 2018
Dec. 31, 2017
Assumptions        
Units at issuance (in shares)     324,802 126,239
Granted on March 12, 2018        
Assumptions        
Expected term 10 years      
Expected volatility (as a percent) 22.00%      
Expected dividend yield (as a percent) 6.00%      
Risk-free interest rate (as a percent) 2.46%      
Fair value of units at issuance $ 90      
Units at issuance (in shares) 3,930      
Fair value share price per unit (in dollars per share) $ 22.90      
Granted on January 5, 2018        
Assumptions        
Expected term   10 years    
Expected volatility (as a percent)   22.00%    
Expected dividend yield (as a percent)   6.00%    
Risk-free interest rate (as a percent)   2.09%    
Fair value of units at issuance   $ 3,447    
Units at issuance (in shares)   137,616    
Fair value share price per unit (in dollars per share)   $ 25.05    
Executive Officer [Member] | Share-based Compensation Award, Tranche One [Member] | Granted on January 5, 2018        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Vesting period (in years)   4 years    
v3.8.0.1
Noncontrolling Interest - LTIP Units (Details) - LTIP Units - USD ($)
$ in Thousands
 3 Months Ended 12 Months Ended
Mar. 31, 2018
Mar. 31, 2017
Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Unrecognized compensation costs $ 7,500    
Unrecognized compensation costs, period for recognition 2 years 9 months 10 days    
Units      
Unvested at beginning of period (in shares) 300,307 403,423 403,423
Granted (in shares) 324,802   126,239
Vested (in shares) (231,041) (67,670) (229,355)
Forfeited (in shares) 0   0
Unvested at end of period (in shares) 394,068   300,307
Fair value of shares vested $ 6,035 $ 1,664  
v3.8.0.1
Equity Incentive Plan - Performance Plan Assumptions (Details) - Performance shares - Awarded in 2018
$ in Thousands
Jan. 05, 2018
USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Value of awards $ 5,456
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 22.00%
Expected dividend yield (as a percent) 6.00%
Risk-free interest rate (as a percent) 2.09%
v3.8.0.1
Equity Incentive Plan - 2018 Activity (Details) - USD ($)
$ in Thousands
 3 Months Ended
Jan. 01, 2018
Mar. 31, 2018
Mar. 31, 2017
LTIP Units      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value   $ 6,035 $ 1,664
Unrecognized compensation costs   $ 7,500  
Unrecognized compensation costs, period for recognition   2 years 9 months 10 days  
Performance shares      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Unrecognized compensation costs   $ 7,800  
Unrecognized compensation costs, period for recognition   2 years 7 months 30 days  
Outperformance Program2015 [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Vesting period (in years) 3 years    
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value $ 6,200    
Outperformance Program2015 [Member] | LTIP Units      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Stock Issued During Period, Shares, Share-based Compensation, Gross 183,256    
Outperformance Program2015 [Member] | Common Stock      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Stock Issued During Period, Shares, Share-based Compensation, Gross 53,722    
Stock Repurchased and Retired During Period, Shares 15,183    
v3.8.0.1
Equity Incentive Plan - Equity Non-cash Compensation Expense (Details) - USD ($)
$ in Thousands
 3 Months Ended
Mar. 31, 2018
Mar. 31, 2017
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 $ 2,220 $ 2,387
General and Administrative Expenses | Independent Director    
Equity Incentive Plan    
Share-based compensation 86 88
General and Administrative Expenses | Restricted stock    
Equity Incentive Plan    
Share-based compensation 434 592
General and Administrative Expenses | LTIP Units    
Equity Incentive Plan    
Share-based compensation 871 1,170
General and Administrative Expenses | Performance shares    
Equity Incentive Plan    
Share-based compensation $ 829 $ 537
v3.8.0.1
Earnings Per Share (Details) - shares
 3 Months Ended
Mar. 31, 2018
Mar. 31, 2017
Earnings Per Share [Abstract]    
Participating securities 201,650 239,827
v3.8.0.1
Earnings Per Share - Reconciliation of Numerator and Denominator (Details) - USD ($)
$ / shares in Units, $ in Thousands
 3 Months Ended
Mar. 31, 2018
Mar. 31, 2017
Numerator    
Net income $ 25,149 $ 69
Less: preferred stock dividends 2,448 2,448
Less: amount allocated to participating securities 71 83
Less: income (loss) attributable to noncontrolling interest after preferred stock dividends 954 (103)
Net income (loss) attributable to common stockholders $ 21,676 $ (2,359)
Denominator    
Weighted average common shares outstanding — basic 97,021,000 81,808,000
Share-based compensation 302,000 0
Weighted average common shares outstanding — diluted 97,323,000 81,808,000
Net income (loss) per share — basic and diluted    
Net income (loss) per share attributable to common stockholders — basic $ 0.22 $ (0.03)
Net income (loss) per share attributable to common stockholders — diluted $ 0.22 $ (0.03)
Restricted stock    
Net income (loss) per share — basic and diluted    
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount 202,000 240,000
Performance shares    
Net income (loss) per share — basic and diluted    
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount   438,000
v3.8.0.1
Commitments and Contingencies - Agreements (Details)
$ in Millions
Mar. 31, 2018
USD ($)
Commitments and Contingencies Disclosure [Abstract]  
Letters of credit outstanding $ 5.9
v3.8.0.1
Subsequent Events Subsequent Events - Debt (Details) - Non-recognized Subsequent Event
$ in Millions
Apr. 10, 2018
USD ($)
Rate
$75 Million Series G Unsecured Notes [Member]  
Subsequent Event [Line Items]  
Debt Instrument, Face Amount | $ $ 75.0
Stated interest rate | Rate 4.10%
$100 Million Series H Unsecured Notes [Member]  
Subsequent Event [Line Items]  
Debt Instrument, Face Amount | $ $ 100.0
Stated interest rate | Rate 4.27%