STAG Industrial (STAG) 10-Q 28 Jul 20 2020 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2020	Jul. 27, 2020
Entity Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2020
Document Transition Report	false
Entity File Number	1-34907
Entity Registrant Name	STAG Industrial, Inc.
Entity Incorporation, State or Country Code	MD
Entity Tax Identification Number	27-3099608
Entity Address, Address Line One	One Federal Street
Entity Address, Address Line Two	23rd Floor
Entity Address, City or Town	Boston,
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02110
City Area Code	617
Local Phone Number	574-4777
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		149,141,565
Entity Central Index Key	0001479094
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q2
Amendment Flag	false
Entity Central Index Key	0001479094
Current Fiscal Year End Date	--12-31
Common Stock
Entity Information [Line Items]
Title of 12(b) Security	Common stock, $0.01 par value per share
Trading Symbol	STAG
Security Exchange Name	NYSE
Series C Preferred Stock
Entity Information [Line Items]
Title of 12(b) Security	6.875% Series C Cumulative Redeemable Preferred Stock ($0.01 par value)
Trading Symbol	STAG-PC
Security Exchange Name	NYSE

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Rental Property:
Land	$ 444,489	$ 435,923
Buildings and improvements, net of accumulated depreciation of $446,361 and $387,633, respectively	3,141,970	3,087,435
Deferred leasing intangibles, net of accumulated amortization of $267,553 and $241,304, respectively	451,738	475,149
Total rental property, net	4,038,197	3,998,507
Cash and cash equivalents	102,097	9,041
Restricted cash	12,505	2,823
Tenant accounts receivable	65,122	57,592
Prepaid expenses and other assets	39,347	38,231
Interest rate swaps	0	303
Operating lease right-of-use assets	22,168	15,129
Assets held for sale, net	0	43,019
Total assets	4,279,436	4,164,645
Liabilities:
Unsecured credit facility	0	146,000
Unsecured term loans, net	970,282	871,375
Unsecured notes, net	573,082	572,883
Mortgage notes, net	52,827	54,755
Accounts payable, accrued expenses and other liabilities	58,783	53,737
Interest rate swaps	50,731	18,819
Tenant prepaid rent and security deposits	24,542	21,993
Dividends and distributions payable	18,301	17,465
Deferred leasing intangibles, net of accumulated amortization of $13,117 and $12,064, respectively	26,292	26,738
Operating lease liabilities	24,279	16,989
Total liabilities	1,799,119	1,800,754
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Common stock, par value $0.01 per share, 300,000,000 shares authorized at June 30, 2020 and December 31, 2019, respectively, 148,941,121 and 142,815,593 shares issued and outstanding at June 30, 2020 and December 31, 2019, respectively	1,489	1,428
Additional paid-in capital	3,148,163	2,970,553
Cumulative dividends in excess of earnings	(750,770)	(723,027)
Accumulated other comprehensive loss	(49,837)	(18,426)
Total stockholders’ equity	2,424,045	2,305,528
Noncontrolling interest	56,272	58,363
Total equity	2,480,317	2,363,891
Total liabilities and equity	4,279,436	4,164,645
Series C Preferred Stock
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Preferred stock	$ 75,000	$ 75,000

Consolidated Balance Sheet (Par

Consolidated Balance Sheet (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Building and Improvements, accumulated depreciation	$ 446,361	$ 387,633
Deferred leasing intangible assets, accumulated amortization	267,553	241,304
Deferred leasing intangible liabilities, accumulated amortization	$ 13,117	$ 12,064
Preferred Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Preferred Stock, Shares Authorized	20,000,000	20,000,000
Preferred Stock, Shares Outstanding	3,000,000	3,000,000
Common Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Common Stock, Shares Authorized	300,000,000	300,000,000
Common Stock, Shares, Issued	148,941,121	142,815,593
Common Stock, Shares, Outstanding	148,941,121	142,815,593
Series C Preferred Stock
Preferred Stock, Shares Issued	3,000,000	3,000,000
Preferred Stock, Liquidation Preference Per Share	$ 25	$ 25

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Revenues [Abstract]
Rental income	$ 117,471	$ 96,362	$ 235,810	$ 191,977
Other income	146	284	355	371
Total revenue	117,617	96,646	236,165	192,348
Expenses
Property	20,392	16,955	42,339	36,466
General and administrative	9,406	8,587	19,779	17,799
Depreciation and amortization	53,606	44,633	106,294	86,936
Loss on impairments	0	0	0	5,344
Other expenses	588	427	1,064	826
Total expenses	83,992	70,602	169,476	147,371
Other income (expense)
Interest and other income	156	2	235	18
Interest expense	(15,333)	(12,193)	(30,197)	(25,027)
Loss on extinguishment of debt	(834)	0	(834)	0
Gain on involuntary conversion	657	0	657	0
Gain on the sales of rental property, net	1,045	317	47,804	1,591
Total other income (expense)	(14,309)	(11,874)	17,665	(23,418)
Net income	19,316	14,170	84,354	21,559
Less: income attributable to noncontrolling interest after preferred stock dividends	407	408	2,005	622
Net income attributable to STAG Industrial, Inc.	18,909	13,762	82,349	20,937
Less: preferred stock dividends	1,289	1,289	2,578	2,578
Less: amount allocated to participating securities	68	79	136	158
Net income attributable to common stockholders	$ 17,552	$ 12,394	$ 79,635	$ 18,201
Weighted average common shares outstanding — basic	148,663	125,251	148,116	120,015
Weighted average common shares outstanding — diluted	149,027	125,560	148,341	120,306
Net income per share — basic and diluted
Net income per share attributable to common stockholders — basic	$ 0.12	$ 0.10	$ 0.54	$ 0.15
Net income per share attributable to common stockholders — diluted	$ 0.12	$ 0.10	$ 0.54	$ 0.15

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 19,316	$ 14,170	$ 84,354	$ 21,559
Other comprehensive loss:
Loss on interest rate swaps	(2,009)	(16,028)	(32,200)	(23,006)
Other comprehensive loss	(2,009)	(16,028)	(32,200)	(23,006)
Comprehensive income (loss)	17,307	(1,858)	52,154	(1,447)
Income attributable to noncontrolling interest after preferred stock dividends	(407)	(408)	(2,005)	(622)
Other comprehensive loss attributable to noncontrolling interest	32	510	789	754
Comprehensive income (loss) attributable to STAG Industrial, Inc.	$ 16,932	$ (1,756)	$ 50,938	$ (1,315)

Consolidated Statements of Equi

Consolidated Statements of Equity - USD ($) $ in Thousands	Total	Preferred Stock	Common Stock	Additional Paid-in Capital	Cumulative Dividends in excess of Earnings	Accumulated Other Comprehensive Income (Loss)	Total Stockholders' Equity	Noncontrolling Interest - Unit holders in Operating Partnership
Balance at Dec. 31, 2018	$ 1,669,632	$ 75,000	$ 1,122	$ 2,118,179	$ (584,979)	$ 4,481	$ 1,613,803	$ 55,829
Balance (in shares) at Dec. 31, 2018			112,165,786
Increase (Decrease) in Stockholders' Equity
Cumulative Effect of New Accoutning Principle in Period of Adoption	(214)				(214)		(214)
Proceeds from sales of common stock, net	384,865		$ 137	384,728			384,865
Proceeds from sales of common stock (in shares)			13,622,203
Dividends, Common Stock					(89,130)
Dividends							(89,130)
Dividends and Distributions, Net	(93,002)
Distribution Made to Limited Partner, Cash Distributions Declared								(3,872)
Non-cash compensation activity, net	3,418			523			151	3,267
Non-cash compensation activity (in shares)			131,026
Non-cash compensation activity (in excess of earnings)			$ (1)		(373)
Redemption of common units to common stock			$ 4	6,231			6,235	6,235
Redemption of common units to common stock (in shares)			453,930
Rebalancing of noncontrolling interest				(8,648)			(8,648)	8,648
Other comprehensive loss	(23,006)					(22,252)	(22,252)	(754)
Net income	21,559				20,937		20,937	622
Balance at Jun. 30, 2019	1,963,252	75,000	$ 1,264	2,501,013	(653,759)	(17,771)	1,905,747	57,505
Balance (in shares) at Jun. 30, 2019			126,372,945
Balance at Dec. 31, 2018	1,669,632	75,000	$ 1,122	2,118,179	(584,979)	4,481	1,613,803	55,829
Balance (in shares) at Dec. 31, 2018			112,165,786
Balance at Dec. 31, 2019	2,363,891	75,000	$ 1,428	2,970,553	(723,027)	(18,426)	2,305,528	58,363
Balance (in shares) at Dec. 31, 2019			142,815,593
Balance at Mar. 31, 2019	1,774,841	75,000	$ 1,182	2,266,695	(621,225)	(2,253)	1,719,399	55,442
Balance (in shares) at Mar. 31, 2019			118,174,102
Increase (Decrease) in Stockholders' Equity
Proceeds from sales of common stock, net	236,336		$ 82	236,254			236,336
Proceeds from sales of common stock (in shares)			8,180,794
Dividends, Common Stock					(46,296)
Dividends							(46,296)
Dividends and Distributions, Net	(48,622)
Distribution Made to Limited Partner, Cash Distributions Declared								(2,326)
Non-cash compensation activity, net	2,555			1,656			1,656	899
Non-cash compensation activity (in shares)			3,190
Non-cash compensation activity (in excess of earnings)			$ 0		0
Redemption of common units to common stock			$ 0	207			207	(207)
Redemption of common units to common stock (in shares)			14,859
Rebalancing of noncontrolling interest				(3,799)			(3,799)	3,799
Other comprehensive loss	(16,028)					(15,518)	(15,518)	(510)
Net income	14,170				13,762		13,762	408
Balance at Jun. 30, 2019	1,963,252	75,000	$ 1,264	2,501,013	(653,759)	(17,771)	1,905,747	57,505
Balance (in shares) at Jun. 30, 2019			126,372,945
Balance at Dec. 31, 2019	2,363,891	75,000	$ 1,428	2,970,553	(723,027)	(18,426)	2,305,528	$ 58,363
Balance (in shares) at Dec. 31, 2019			142,815,593
Increase (Decrease) in Stockholders' Equity
Redemption of common units to common stock (in shares)								0
Balance at Mar. 31, 2020	2,517,114	75,000	$ 1,487	3,142,495	(714,799)	(47,860)	2,456,323	$ 60,791
Balance (in shares) at Mar. 31, 2020			148,708,031
Balance at Dec. 31, 2019	2,363,891	75,000	$ 1,428	2,970,553	(723,027)	(18,426)	2,305,528	58,363
Balance (in shares) at Dec. 31, 2019			142,815,593
Increase (Decrease) in Stockholders' Equity
Proceeds from sales of common stock, net	172,656		$ 56	172,600			172,656
Proceeds from sales of common stock (in shares)			5,600,000
Dividends, Common Stock					(109,702)
Dividends							(109,702)
Dividends and Distributions, Net	(112,703)
Distribution Made to Limited Partner, Cash Distributions Declared								3,001
Non-cash compensation activity, net	4,319			1,112			723	3,596
Non-cash compensation activity (in shares)			77,798
Non-cash compensation activity (in excess of earnings)			$ (1)		(390)
Redemption of common units to common stock			$ 4	7,082			7,086	$ 7,086
Redemption of common units to common stock (in shares)			447,730					0
Rebalancing of noncontrolling interest				(3,184)			(3,184)	$ 3,184
Other comprehensive loss	(32,200)					(31,411)	(31,411)	(789)
Net income	84,354				82,349		82,349	2,005
Balance at Jun. 30, 2020	2,480,317	75,000	$ 1,489	3,148,163	(750,770)	(49,837)	2,424,045	56,272
Balance (in shares) at Jun. 30, 2020			148,941,121
Balance at Mar. 31, 2020	2,517,114	75,000	$ 1,487	3,142,495	(714,799)	(47,860)	2,456,323	60,791
Balance (in shares) at Mar. 31, 2020			148,708,031
Increase (Decrease) in Stockholders' Equity
Proceeds from sales of common stock, net	(67)		$ 0	(67)			(67)
Proceeds from sales of common stock (in shares)			0
Dividends, Common Stock					(54,880)
Dividends							(54,880)
Dividends and Distributions, Net	(56,985)
Distribution Made to Limited Partner, Cash Distributions Declared								(2,105)
Non-cash compensation activity, net	2,948			1,970			1,970	978
Non-cash compensation activity (in shares)			4,750
Non-cash compensation activity (in excess of earnings)			$ 0		0
Redemption of common units to common stock			$ 2	3,656			3,658	(3,658)
Redemption of common units to common stock (in shares)			228,340
Rebalancing of noncontrolling interest				109			109	(109)
Other comprehensive loss	(2,009)					(1,977)	(1,977)	(32)
Net income	19,316				18,909		18,909	407
Balance at Jun. 30, 2020	$ 2,480,317	$ 75,000	$ 1,489	$ 3,148,163	$ (750,770)	$ (49,837)	$ 2,424,045	$ 56,272
Balance (in shares) at Jun. 30, 2020			148,941,121

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Cash flows from operating activities:
Net income	$ 84,354	$ 21,559
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	106,294	86,936
Loss on impairments	0	5,344
Gain on involuntary conversion	(657)	0
Non-cash portion of interest expense	1,422	1,236
Amortization of above and below market leases, net	2,152	2,102
Straight-line rent adjustments, net	(5,498)	(5,522)
Dividends on forfeited equity compensation	0	7
Loss on extinguishment of debt	834	0
Gain on the sales of rental property, net	(47,804)	(1,591)
Non-cash compensation expense	5,790	4,815
Change in assets and liabilities:
Tenant accounts receivable	(475)	1,389
Prepaid expenses and other assets	(4,116)	(3,338)
Accounts payable, accrued expenses and other liabilities	3,243	(1,433)
Tenant prepaid rent and security deposits	2,549	(933)
Total adjustments	63,734	89,012
Net cash provided by operating activities	148,088	110,571
Cash flows from investing activities:
Acquisitions of land and buildings and improvements	(110,121)	(368,188)
Additions of land and building and improvements	(27,299)	(18,949)
Acquisitions of other assets	450	1,049
Proceeds from sales of rental property, net	101,881	17,688
Proceeds from involuntary conversion	782	0
Acquisition deposits, net	660	2,142
Acquisitions of deferred leasing intangibles	(20,542)	(76,188)
Net cash used in investing activities	(55,089)	(444,544)
Cash flows from financing activities:
Proceeds from unsecured credit facility	387,000	381,000
Repayment of unsecured credit facility	(533,000)	(352,500)
Proceeds from unsecured term loans	400,000	0
Repayment of unsecured term loans	(300,000)	0
Repayment of mortgage notes	(1,993)	(961)
Payment of loan fees and costs	1,129	48
Payment of defeasance fees and other costs	(425)	0
Proceeds from sales of common stock, net	172,626	384,913
Dividends and distributions	111,868	89,934
Repurchase and retirement of share-based compensation	(1,472)	(1,444)
Net cash provided by financing activities	9,739	321,026
Increase (decrease) in cash and cash equivalents and restricted cash	102,738	(12,947)
Cash and cash equivalents and restricted cash—beginning of period	11,864	22,542
Cash and cash equivalents and restricted cash—end of period	114,602	9,595
Supplemental disclosure:
Cash paid for interest, net of capitalized interest	28,520	21,965
Supplemental schedule of non-cash investing and financing activities
Acquisitions of land and buildings and improvements	111	72
Acquisitions of deferred leasing intangibles	33	24
Change in additions of land, building, and improvements included in accounts payable, accrued expenses, and other liabilities	683	(7,351)
Additions to building and other capital improvements from non-cash compensation	(17)	(40)
Change in loan fees, costs, and offering costs included in accounts payable, accrued expenses, and other liabilities	(1,020)	(62)
Leases cumulative effect adjustment	0	(214)
Dividends and distributions payable	$ 18,301	$ 16,822

Organization and Description of

Organization and Description of Business	6 Months Ended
	Jun. 30, 2020
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 June 30, 2020 and December 31, 2019, the Company owned a 97.7% and 97.5%, 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 June 30, 2020, the Company owned 457 buildings in 38 states with approximately 91.8 million rentable square feet, consisting of 379 warehouse/distribution buildings, 70 light manufacturing buildings, and eight flex/office buildings. COVID-19 Pandemic Currently, one of the most significant risks and uncertainties facing the Company and the real estate industry generally is the potential adverse effect of the ongoing public health crisis of the novel coronavirus disease (“COVID-19”) pandemic. The Company closely monitors the effect of the COVID-19 pandemic on all aspects of its business, including how the pandemic will affect its tenants and business partners. While the Company did not incur significant disruptions from the COVID-19 pandemic during the six months ended June 30, 2020, a number of the Company’s tenants requested rent deferral or rent abatement as a result of the pandemic and other tenants may make requests in the future. The Company entered into a limited number of rent deferral agreements during the three months ended June 30, 2020, which resulted in approximately $1.5 million of rent deferrals during the three and six months ended June 30, 2020. The Company evaluates tenant rent relief requests on an individual basis, considering a number of factors. Not all tenant requests will ultimately result in modified agreements, nor is the Company foregoing its contractual rights under its lease agreements. The Company is unable to predict the impact that the pandemic will have on its financial condition, results of operations and cash flows due to numerous uncertainties. The extent to which the COVID-19 pandemic affects the Company’s operations and those of its tenants will depend on future developments, which are highly uncertain and cannot be predicted with confidence, including the scope, severity and duration of the pandemic, the actions taken to contain the pandemic or mitigate its impact, and the direct and indirect economic effects of the pandemic and containment measures, among others.

Summary of Significant Accounti

Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2020
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, 2019. 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 and restated (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. New Accounting Standards In March 2020, the Financial Accounting Standards Board issued Accounting Standards Update (“ASU”) 2020-04, Reference Rate Reform (Topic 848) . ASU 2020-04 contains practical expedients for reference rate reform related activities that impact debt, leases, derivatives and other contracts. The guidance in ASU 2020-04 is optional and may be elected over time as reference rate reform activities occur. During the quarter ended March 31, 2020, the Company elected to apply the hedge accounting expedients related to probability and the assessments of effectiveness for future LIBOR-indexed cash flows to assume that the index upon which future hedged transactions will be based matches the index on the corresponding derivatives. Application of these expedients preserves the presentation of derivatives consistent with past presentation. The Company continues to evaluate the impact of the guidance and may apply other elections as applicable as additional changes in the market occur. 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. Reconciliation of cash and cash equivalents and restricted cash (in thousands) June 30, 2020 December 31, 2019 Cash and cash equivalents $ 102,097 $ 9,041 Restricted cash 12,505 2,823 Total cash and cash equivalents and restricted cash $ 114,602 $ 11,864 Taxes Federal Income Taxes The Company’s taxable REIT subsidiaries recognized net income of approximately $0, $0, $0.3 million and $0.3 million for the three and six months ended June 30, 2020 and 2019, 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 $0.5 million, $0.9 million, $0.4 million and $0.6 million have been recorded in other expenses on the accompanying Consolidated Statements of Operations for the three and six months ended June 30, 2020 and 2019, respectively. Uncertain Tax Positions As of June 30, 2020 and December 31, 2019, there were no liabilities for uncertain tax positions. Concentrations of Credit Risk

Rental Property

Rental Property	6 Months Ended
	Jun. 30, 2020
Real Estate [Abstract]
Rental Property	Rental Property The following table summarizes the components of rental property as of June 30, 2020 and December 31, 2019. Rental Property (in thousands) June 30, 2020 December 31, 2019 Land $ 444,489 $ 435,923 Buildings, net of accumulated depreciation of $292,467 and $254,458, respectively 2,833,458 2,787,234 Tenant improvements, net of accumulated depreciation of $23,724 and $21,487, respectively 38,638 38,339 Building and land improvements, net of accumulated depreciation of $130,170 and $111,688, respectively 239,214 232,456 Construction in progress 30,660 29,406 Deferred leasing intangibles, net of accumulated amortization of $267,553 and $241,304, respectively 451,738 475,149 Total rental property, net $ 4,038,197 $ 3,998,507 Acquisitions The following table summarizes the acquisitions of the Company during the three and six months ended June 30, 2020. Market (1) Date Acquired Square Feet Buildings Purchase Price Detroit, MI January 10, 2020 491,049 1 $ 29,543 Rochester, NY January 10, 2020 124,850 1 8,565 Minneapolis/St Paul, MN February 6, 2020 139,875 1 10,460 Sacramento, CA February 6, 2020 160,534 1 18,468 Richmond, VA February 6, 2020 78,128 1 5,481 Milwaukee/Madison, WI February 7, 2020 81,230 1 7,219 Detroit, MI February 11, 2020 311,123 1 23,141 Philadelphia, PA March 9, 2020 78,000 1 6,571 Tulsa, OK March 9, 2020 134,600 1 9,895 Three months ended March 31, 2020 1,599,389 9 119,343 Sacramento, CA June 11, 2020 54,463 1 5,730 Chicago, IL June 29, 2020 67,817 1 6,184 Three months ended June 30, 2020 122,280 2 11,914 Six months ended June 30, 2020 1,721,669 11 $ 131,257 (1) As defined by CoStar Realty Information Inc (“CoStar”). If the building is located outside of a CoStar defined market, the city and state is reflected. The following table summarizes the allocation of the consideration paid at the date of acquisition during the six months ended June 30, 2020 for the acquired assets and liabilities in connection with the acquisitions identified in the table above. Acquired Assets and Liabilities Purchase Price (in thousands) Weighted Average Amortization Period (years) of Intangibles at Acquisition Land $ 10,498 N/A Buildings 92,860 N/A Tenant improvements 1,535 N/A Building and land improvements 4,670 N/A Construction in progress 669 N/A Other assets 450 N/A Deferred leasing intangibles - In-place leases 14,963 7.9 Deferred leasing intangibles - Tenant relationships 7,115 11.1 Deferred leasing intangibles - Above market leases 1,069 6.3 Deferred leasing intangibles - Below market leases (2,572) 5.4 Total purchase price $ 131,257 The following table summarizes the results of operations for the three and six months ended June 30, 2020 for the buildings acquired during the six months ended June 30, 2020 included in the Company’s Consolidated Statements of Operations from the date of acquisition. Results of Operations (in thousands) Three months ended June 30, 2020 Six months ended June 30, 2020 Total revenue $ 2,807 $ 4,748 Net income $ 609 $ 861 Dispositions During the six months ended June 30, 2020, the Company sold four buildings to third parties comprised of approximately 1.2 million rentable square feet with a net book value of approximately $54.1 million. These buildings contributed approximately $0, $0, $1.1 million and $2.5 million to revenue for the three and six months ended June 30, 2020 and 2019, respectively. These buildings contributed approximately $(49,000), $(0.2) million, $(35,000) and $0.4 million to net income (loss) (exclusive of gain on the sales of rental property, net and loss on extinguishment of debt) for the three and six months ended June 30, 2020 and 2019, respectively. Net proceeds from the sales of rental property were approximately $101.9 million and the Company recognized the full gain on the sales of rental property, net, of approximately $47.8 million for the six months ended June 30, 2020. Loss on Impairments During the three and six months ended June 30, 2020, the Company did not recognize any loss on impairments. During the three and six months ended June 30, 2019, the Company recognized approximately $0 and $5.3 million of loss on impairments related to one building. Gain on Involuntary Conversion During the three and six months ended June 30, 2020, the Company recognized a gain on involuntary conversion of approximately $0.7 million related to an eminent domain taking of a portion of a parcel of land. During the three and six months ended June 30, 2019, the Company did not recognize any gain on involuntary conversion. Deferred Leasing Intangibles The following table summarizes the deferred leasing intangibles on the accompanying Consolidated Balance Sheets as of June 30, 2020 and December 31, 2019. June 30, 2020 December 31, 2019 Deferred Leasing Intangibles (in thousands) Gross Accumulated Amortization Net Gross Accumulated Amortization Net Above market leases $ 92,793 $ (36,413) $ 56,380 $ 92,607 $ (32,115) $ 60,492 Other intangible lease assets 626,498 (231,140) 395,358 623,846 (209,189) 414,657 Total deferred leasing intangible assets $ 719,291 $ (267,553) $ 451,738 $ 716,453 $ (241,304) $ 475,149 Below market leases $ 39,409 $ (13,117) $ 26,292 $ 38,802 $ (12,064) $ 26,738 Total deferred leasing intangible liabilities $ 39,409 $ (13,117) $ 26,292 $ 38,802 $ (12,064) $ 26,738 The following table summarizes the amortization expense and the net decrease to rental income for the amortization of deferred leasing intangibles during the three and six months ended June 30, 2020 and 2019. Three months ended June 30, Six months ended June 30, Deferred Leasing Intangibles Amortization (in thousands) 2020 2019 2020 2019 Net decrease to rental income related to above and below market lease amortization $ 1,174 $ 1,146 $ 2,164 $ 2,113 Amortization expense related to other intangible lease assets $ 21,076 $ 17,899 $ 41,378 $ 34,713 The following table summarizes the amortization of deferred leasing intangibles over the next five calendar years beginning with 2020 as of June 30, 2020. 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 2020 $ 36,982 $ 1,827 2021 $ 65,116 $ 2,717 2022 $ 55,459 $ 2,190 2023 $ 46,930 $ 2,395 2024 $ 38,019 $ 2,703

Debt

Debt	6 Months Ended
	Jun. 30, 2020
Debt Disclosure [Abstract]
Debt	Debt The following table summarizes the Company’s outstanding indebtedness, including borrowings under the Company’s unsecured credit facility, unsecured term loans, unsecured notes, and mortgage notes as of June 30, 2020 and December 31, 2019. Loan Principal Outstanding as of June 30, 2020 (in thousands) Principal Outstanding as of December 31, 2019 (in thousands) Interest Rate (1)(2) Maturity Date Prepayment Terms (3) Unsecured credit facility: Unsecured Credit Facility (4) $ — $ 146,000 L + 0.90% January 12, 2024 i Total unsecured credit facility — 146,000 Unsecured term loans: Unsecured Term Loan C (5) — 150,000 2.39 % September 29, 2020 i Unsecured Term Loan B (5) — 150,000 3.05 % March 21, 2021 i Unsecured Term Loan A 150,000 150,000 3.38 % March 31, 2022 i Unsecured Term Loan D 150,000 150,000 2.85 % January 4, 2023 i Unsecured Term Loan G (6) 300,000 — 3.31 % April 18, 2023 i Unsecured Term Loan E 175,000 175,000 3.92 % January 15, 2024 i Unsecured Term Loan F 200,000 100,000 L + 1.00% January 12, 2025 i Total unsecured term loans 975,000 875,000 Less: Total unamortized deferred financing fees and debt issuance costs (4,718) (3,625) Total carrying value unsecured term loans, net 970,282 871,375 Unsecured notes: Series F Unsecured Notes 100,000 100,000 3.98 % January 5, 2023 ii Series A Unsecured Notes 50,000 50,000 4.98 % October 1, 2024 ii Series D Unsecured Notes 100,000 100,000 4.32 % February 20, 2025 ii Series G Unsecured Notes 75,000 75,000 4.10 % June 13, 2025 ii Series B Unsecured Notes 50,000 50,000 4.98 % July 1, 2026 ii Series C Unsecured Notes 80,000 80,000 4.42 % December 30, 2026 ii Series E Unsecured Notes 20,000 20,000 4.42 % February 20, 2027 ii Series H Unsecured Notes 100,000 100,000 4.27 % June 13, 2028 ii Total unsecured notes 575,000 575,000 Less: Total unamortized deferred financing fees and debt issuance costs (1,918) (2,117) Total carrying value unsecured notes, net 573,082 572,883 Mortgage notes (secured debt): Wells Fargo Bank, National Association CMBS Loan 49,473 51,406 4.31 % December 1, 2022 iii Thrivent Financial for Lutherans 3,619 3,679 4.78 % December 15, 2023 iv Total mortgage notes 53,092 55,085 Add: Total unamortized fair market value premiums 34 39 Less: Total unamortized deferred financing fees and debt issuance costs (299) (369) Total carrying value mortgage notes, net 52,827 54,755 Total / weighted average interest rate (7) $ 1,596,191 $ 1,645,013 3.48 % (1) Interest rate as of June 30, 2020. At June 30, 2020, the one-month LIBOR (“L”) was 0.16225%. The current interest rate is not adjusted to include the amortization of deferred financing fees or debt issuance costs incurred in obtaining debt or any unamortized fair market value premiums. The spread over the applicable rate for the Company’s unsecured credit facility and unsecured term loans is based on the Company’s debt rating, as defined in the respective loan agreements. (2) The unsecured term loans have a stated interest rate of one-month LIBOR plus a spread of 1.0%, with the exception of the Unsecured Term Loan G which has a spread of 1.5% and is subject to a minimum rate for LIBOR of 0.25%. As of June 30, 2020, one-month LIBOR for the Unsecured Term Loans A, D, E, and G was swapped to a fixed rate of 2.38%, 1.85%, 2.92%, and 1.72%, respectively. One-month LIBOR for the Unsecured Term Loan F was swapped to a fixed rate of 2.11% effective July 15, 2020. One-month LIBOR for the Unsecured Term Loan G will be swapped to a fixed rate of 1.17% effective September 29, 2020 and 0.28% effective March 19, 2021. (3) 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; and (iv) pre-payable without penalty three months prior to the maturity date. (4) The capacity of the unsecured credit facility is $500.0 million. Deferred financing fees and debt issuance costs, net of accumulated amortization related to the unsecured credit facility of approximately $2.0 million and $2.4 million is included in prepaid expenses and other assets on the accompanying Consolidated Balance Sheets as of June 30, 2020 and December 31, 2019, respectively. The initial maturity date is January 15, 2023, which may be extended pursuant to two six (5) The Unsecured Term Loan B and the Unsecured Term Loan C were paid in full on April 17, 2020 in connection with the execution of the Unsecured Term Loan G. (6) The initial maturity date is April 16, 2021, which may be extended pursuant to two one-year extension options exercisable by the Company in its discretion upon advance written notice. Exercise of each one-year option is subject to the following conditions: (i) absence of a default immediately before the extension and immediately after giving effect to the extension, (ii) accuracy of representations and warranties as of the extension date (both immediately before and after the extension), as if made on the extension date, and (iii) payment of a fee. Neither extension option is subject to lender consent, assuming proper notice and satisfaction of the conditions. (7) The weighted average interest rate was calculated using the fixed interest rate swapped on the notional amount of $775.0 million of debt, and is not adjusted to include the amortization of deferred financing fees or debt issuance costs incurred in obtaining debt or any unamortized fair market value premiums. The aggregate undrawn nominal commitment on the unsecured credit facility as of June 30, 2020 was approximately $497.0 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 $6.1 million and $6.3 million as of June 30, 2020 and December 31, 2019, respectively, and is included in accounts payable, accrued expenses and other liabilities on the accompanying Consolidated Balance Sheets. The following table summarizes the costs included in interest expense related to the Company’s debt arrangements on the accompanying Consolidated Statement of Operations for the three and six months ended June 30, 2020 and 2019. Three months ended June 30, Six months ended June 30, Costs Included in Interest Expense (in thousands) 2020 2019 2020 2019 Amortization of deferred financing fees and debt issuance costs and fair market value premiums $ 746 $ 618 $ 1,422 $ 1,236 Facility, unused, and other fees $ 316 $ 387 $ 680 $ 770 On April 29, 2020, the mortgage note associated with the Wells Fargo, National Association CMBS Loan was partially defeased in the amount of approximately $1.0 million in connection with the sale of the Johnstown, NY property, which had served as partial collateral for the mortgage note. The associated defeasance fees and unamortized deferred financing fees and debt issuance costs of approximately $0.1 million were written off to loss on extinguishment of debt in the accompanying Consolidated Statement of Operations during the three and six months ended June 30, 2020. On April 17, 2020, the Company entered into the $300.0 million Unsecured Term Loan G with Wells Fargo, National Association, as administrative agent on behalf of the various lenders under the agreement. In connection with execution of the Unsecured Term Loan G, the Unsecured Term Loan B and Unsecured Term Loan C were paid in full. As of June 30, 2020, the Unsecured Term Loan G bore an interest rate of LIBOR plus a spread of 1.5% based on the Company’s debt rating, as defined in the loan agreement, and subject to a minimum rate for LIBOR of 0.25%. The Unsecured Term Loan G matures on April 16, 2021, subject to two one On March 25, 2020, the Company drew the remaining $100.0 million of the $200.0 million Unsecured Term Loan F that was entered into on July 12, 2019. Financial Covenant Considerations The Company was in compliance with all financial and other covenants as of June 30, 2020 and December 31, 2019 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 $82.8 million and $85.5 million at June 30, 2020 and December 31, 2019, respectively, and is limited to senior, property-level secured debt financing arrangements. Fair Value of Debt The following table summarizes the aggregate principal outstanding under the Company’s debt arrangements and the corresponding estimate of fair value as of June 30, 2020 and December 31, 2019. June 30, 2020 December 31, 2019 Indebtedness (in thousands) Principal Outstanding Fair Value Principal Outstanding Fair Value Unsecured credit facility $ — $ — $ 146,000 $ 146,000 Unsecured term loans 975,000 964,497 875,000 875,000 Unsecured notes 575,000 617,073 575,000 614,493 Mortgage notes 53,092 55,227 55,085 56,021 Total principal amount 1,603,092 $ 1,636,797 1,651,085 $ 1,691,514 Add: Total unamortized fair market value premiums 34 39 Less: Total unamortized deferred financing fees and debt issuance costs (6,935) (6,111) Total carrying value $ 1,596,191 $ 1,645,013

Derivative Financial Instrument

Derivative Financial Instruments	6 Months Ended
	Jun. 30, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Use of Derivative Financial Instruments	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 summarizes the Company’s outstanding interest rate swaps as of June 30, 2020. All of the Company’s interest rate swaps are designated as qualifying cash flow hedges. Interest Rate Trade Date Effective Date Notional Amount Fair Value Pay Fixed Interest Rate Receive Variable Interest Rate Maturity Date The Toronto-Dominion Bank Oct-14-2015 Sep-29-2016 $ 25,000 $ (76) 1.3830 % One-month L Sep-29-2020 PNC Bank, N.A. Oct-14-2015 Sep-29-2016 $ 50,000 $ (153) 1.3906 % One-month L Sep-29-2020 Regions Bank Oct-14-2015 Sep-29-2016 $ 35,000 $ (106) 1.3858 % One-month L Sep-29-2020 U.S. Bank, N.A. Oct-14-2015 Sep-29-2016 $ 25,000 $ (77) 1.3950 % One-month L Sep-29-2020 Capital One, N.A. Oct-14-2015 Sep-29-2016 $ 15,000 $ (46) 1.3950 % One-month L Sep-29-2020 Royal Bank of Canada Jan-08-2015 Mar-20-2015 $ 25,000 $ (280) 1.7090 % One-month L Mar-21-2021 The Toronto-Dominion Bank Jan-08-2015 Mar-20-2015 $ 25,000 $ (280) 1.7105 % One-month L Mar-21-2021 The Toronto-Dominion Bank Jan-08-2015 Sep-10-2017 $ 100,000 $ (1,493) 2.2255 % One-month L Mar-21-2021 Wells Fargo, N.A. Jan-08-2015 Mar-20-2015 $ 25,000 $ (750) 1.8280 % One-month L Mar-31-2022 The Toronto-Dominion Bank Jan-08-2015 Feb-14-2020 $ 25,000 $ (1,027) 2.4535 % One-month L Mar-31-2022 Regions Bank Jan-08-2015 Feb-14-2020 $ 50,000 $ (2,072) 2.4750 % One-month L Mar-31-2022 Capital One, N.A. Jan-08-2015 Feb-14-2020 $ 50,000 $ (2,121) 2.5300 % One-month L Mar-31-2022 The Toronto-Dominion Bank Jul-20-2017 Oct-30-2017 $ 25,000 $ (1,093) 1.8485 % One-month L Jan-04-2023 Royal Bank of Canada Jul-20-2017 Oct-30-2017 $ 25,000 $ (1,094) 1.8505 % One-month L Jan-04-2023 Wells Fargo, N.A. Jul-20-2017 Oct-30-2017 $ 25,000 $ (1,094) 1.8505 % One-month L Jan-04-2023 PNC Bank, N.A. Jul-20-2017 Oct-30-2017 $ 25,000 $ (1,093) 1.8485 % One-month L Jan-04-2023 PNC Bank, N.A. Jul-20-2017 Oct-30-2017 $ 50,000 $ (2,184) 1.8475 % One-month L Jan-04-2023 The Toronto-Dominion Bank Apr-20-2020 Sep-29-2020 $ 75,000 $ (290) 0.2750 % One-month L Apr-18-2023 Wells Fargo, N.A. Apr-20-2020 Sep-29-2020 $ 75,000 $ (298) 0.2790 % One-month L Apr-18-2023 The Toronto-Dominion Bank Apr-20-2020 Mar-19-2021 $ 75,000 $ (251) 0.2750 % One-month L Apr-18-2023 Wells Fargo, N.A. Apr-20-2020 Mar-19-2021 $ 75,000 $ (258) 0.2800 % One-month L Apr-18-2023 The Toronto-Dominion Bank Jul-24-2018 Jul-26-2019 $ 50,000 $ (4,932) 2.9180 % One-month L Jan-12-2024 PNC Bank, N.A. Jul-24-2018 Jul-26-2019 $ 50,000 $ (4,932) 2.9190 % One-month L Jan-12-2024 Bank of Montreal Jul-24-2018 Jul-26-2019 $ 50,000 $ (4,932) 2.9190 % One-month L Jan-12-2024 U.S. Bank, N.A. Jul-24-2018 Jul-26-2019 $ 25,000 $ (2,466) 2.9190 % One-month L Jan-12-2024 Wells Fargo, N.A. May-02-2019 Jul-15-2020 $ 50,000 $ (4,633) 2.2460 % One-month L Jan-15-2025 U.S. Bank, N.A. May-02-2019 Jul-15-2020 $ 50,000 $ (4,632) 2.2459 % One-month L Jan-15-2025 Regions Bank May-02-2019 Jul-15-2020 $ 50,000 $ (4,632) 2.2459 % One-month L Jan-15-2025 Bank of Montreal Jul-16-2019 Jul-15-2020 $ 50,000 $ (3,436) 1.7165 % One-month L Jan-15-2025 The following table summarizes the fair value of the interest rate swaps outstanding as of June 30, 2020 and December 31, 2019. Balance Sheet Line Item (in thousands) Notional Amount June 30, 2020 Fair Value June 30, 2020 Notional Amount December 31, 2019 Fair Value December 31, 2019 Interest rate swaps-Asset $ — $ — $ 250,000 $ 303 Interest rate swaps-Liability $ 1,275,000 $ (50,731) $ 850,000 $ (18,819) 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 (loss) and subsequently reclassified into interest expense in the same periods during which the hedged transaction affects earnings. Amounts reported in accumulated other comprehensive income (loss) related to derivatives designated as qualifying cash flow hedges will be reclassified to interest expense as interest payments are made on the Company’s variable rate debt. The Company estimates that approximately $17.5 million will be reclassified from accumulated other comprehensive loss as an increase to interest expense over the next 12 months. The following table summarizes the effect of cash flow hedge accounting and the location in the consolidated financial statements for the three and six months ended June 30, 2020 and 2019. Three months ended June 30, Six months ended June 30, Effect of Cash Flow Hedge Accounting (in thousands) 2020 2019 2020 2019 Loss recognized in accumulated other comprehensive loss on interest rate swaps $ 5,249 $ 14,946 $ 36,336 $ 20,802 Income (loss) reclassified from accumulated other comprehensive loss into income as interest expense $ (3,240) $ 1,082 $ (4,136) $ 2,204 Total interest expense presented in the Consolidated Statements of Operations in which the effects of cash flow hedges are recorded $ 15,333 $ 12,193 $ 30,197 $ 25,027 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 June 30, 2020, the Company had not breached the provisions of these agreements and had not posted any collateral related to these agreements. If the Company had breached any of these provisions at June 30, 2020, it could have been required to settle its obligations under the agreement of the interest rate swaps in a net liability position by counterparty plus accrued interest for approximately $51.6 million. Fair Value of Interest Rate Swaps The Company’s valuation of the interest rate swaps is determined using widely accepted valuation techniques including discounted cash flow analysis on the expected cash flows of each derivative. This analysis reflects the contractual terms of the derivatives, including the period to maturity, and uses observable market-based inputs including interest rate curves. The Company incorporates credit valuation adjustments to appropriately reflect both its own nonperformance risk and the respective counterparty’s nonperformance risk in the fair value measurements. In adjusting the fair value of its derivative contracts for the effect of nonperformance risk, the Company has considered the impact of netting and any applicable credit enhancements, such as collateral postings, thresholds, mutual puts, and guarantees. Although the Company has determined that the majority of the inputs used to value its derivatives fall within Level 2 of the fair value hierarchy, the credit valuation adjustments associated with its derivatives utilize Level 3 inputs, such as estimates of current credit spreads to evaluate the likelihood of default by itself and its counterparties. However, as of June 30, 2020 and December 31, 2019, 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 table summarizes the Company’s financial instruments that are accounted for at fair value on a recurring basis as of June 30, 2020 and December 31, 2019. Fair Value Measurements as of June 30, 2020 Using Balance Sheet Line Item (in thousands) Fair Value June 30, 2020 Level 1 Level 2 Level 3 Interest rate swaps-Asset $ — $ — $ — $ — Interest rate swaps-Liability $ (50,731) $ — $ (50,731) $ — Fair Value Measurements as of December 31, 2019 Using Balance Sheet Line Item (in thousands) Fair Value December 31, 2019 Level 1 Level 2 Level 3 Interest rate swaps-Asset $ 303 $ — $ 303 $ — Interest rate swaps-Liability $ (18,819) $ — $ (18,819) $ —

Equity

Equity	6 Months Ended
	Jun. 30, 2020
Stockholders' Equity Note [Abstract]
Equity	Equity Preferred Stock The following table summarizes the Company’s outstanding preferred stock issuances as of June 30, 2020. Preferred Stock Issuances Issuance Date Number of Shares Liquidation Value Per Share Interest Rate 6.875% Series C Cumulative Redeemable Preferred Stock ("Series C Preferred Stock") March 17, 2016 3,000,000 $ 25.00 6.875 % The following tables summarize the dividends attributable to the Company’s outstanding preferred stock issuances during the six months ended June 30, 2020 and the year ended December 31, 2019. Quarter Ended 2020 Declaration Date Series C Payment Date June 30 April 9, 2020 $ 0.4296875 June 30, 2020 March 31 January 8, 2020 0.4296875 March 31, 2020 Total $ 0.8593750 Quarter Ended 2019 Declaration Date Series C Payment Date December 31 October 15, 2019 $ 0.4296875 December 31, 2019 September 30 July 15, 2019 0.4296875 September 30, 2019 June 30 April 9, 2019 0.4296875 July 1, 2019 March 31 January 10, 2019 0.4296875 April 1, 2019 Total $ 1.7187500 On July 9, 2020, the Company’s board of directors declared the Series C Preferred Stock dividends for the quarter ending September 30, 2020 at a quarterly rate of $0.4296875 per share. Common Stock The following table summarizes the terms of the Company’s at-the market (“ATM”) common stock offering program as of June 30, 2020. ATM Common Stock Offering Program Date Maximum Aggregate Offering Price (in thousands) Aggregate Common Stock Available as of June 30, 2020 (in thousands) 2019 $600 million ATM February 14, 2019 $ 600,000 $ 318,248 The table below summarizes the activity under the ATM common stock offering program during the year ended December 31, 2019 (in thousands, except share data). There was no activity under the ATM common stock offering program during the six months ended June 30, 2020. Year ended December 31, 2019 ATM Common Stock Offering Program Shares Weighted Average Price Per Share Net 2019 $600 million ATM 9,711,706 $ 29.01 $ 279,156 Total/weighted average 9,711,706 $ 29.01 $ 279,156 On January 13, 2020, the Company completed an underwritten public offering of an aggregate 10,062,500 shares of common stock at a price to the underwriters of $30.9022 per share, consisting of (i) 5,600,000 shares offered directly by the Company and (ii) 4,462,500 shares offered by the forward dealer in connection with certain forward sale agreements (including 1,312,500 shares offered pursuant to the underwriters’ option to purchase additional shares, which option was exercised in full). The offering closed on January 16, 2020 and the Company received net proceeds from the sale of shares offered directly by the Company of approximately $173.1 million. Subject to the Company’s right to elect cash or net share settlement, the Company has the ability to settle the forward sales agreements at any time through scheduled maturity date of the forward sale agreements of January 13, 2021. The following tables summarize the dividends attributable to the Company’s outstanding shares of common stock that were declared during the six months ended June 30, 2020 and the year ended December 31, 2019. Month Ended 2020 Declaration Date Record Date Per Share Payment Date June 30 April 9, 2020 June 30, 2020 $ 0.12 July 15, 2020 May 31 April 9, 2020 May 29, 2020 0.12 June 15, 2020 April 30 April 9, 2020 April 30, 2020 0.12 May 15, 2020 March 31 January 8, 2020 March 31, 2020 0.12 April 15, 2020 February 29 January 8, 2020 February 28, 2020 0.12 March 16, 2020 January 31 January 8, 2020 January 31, 2020 0.12 February 18, 2020 Total $ 0.72 Month Ended 2019 Declaration Date Record Date Per Share Payment Date December 31 October 15, 2019 December 31, 2019 $ 0.119167 January 15, 2020 November 30 October 15, 2019 November 29, 2019 0.119167 December 16, 2019 October 31 October 15, 2019 October 31, 2019 0.119167 November 15, 2019 September 30 July 15, 2019 September 30, 2019 0.119167 October 15, 2019 August 31 July 15, 2019 August 30, 2019 0.119167 September 16, 2019 July 31 July 15, 2019 July 31, 2019 0.119167 August 15, 2019 June 30 April 9, 2019 June 28, 2019 0.119167 July 15, 2019 May 31 April 9, 2019 May 31, 2019 0.119167 June 17, 2019 April 30 April 9, 2019 April 30, 2019 0.119167 May 15, 2019 March 31 January 10, 2019 March 29, 2019 0.119167 April 15, 2019 February 28 January 10, 2019 February 28, 2019 0.119167 March 15, 2019 January 31 January 10, 2019 January 31, 2019 0.119167 February 15, 2019 Total $ 1.430004 On July 9, 2020, the Company’s board of directors declared the common stock dividends for the months ending July 31, 2020, August 31, 2020, and September 30, 2020 at a monthly rate of $0.12 per share of common stock. Restricted Shares of Common Stock Restricted shares of common stock granted on February 13, 2020 and January 8, 2020 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 2021. Refer to Note 8 for a discussion of the restricted shares of common stock granted on January 8, 2020 pursuant to the January 6, 2017 performance units. The following table summarizes activity related to the Company’s unvested restricted shares of common stock for the six months ended June 30, 2020 and the year ended December 31, 2019. Unvested Restricted Shares of Common Stock Shares Balance at December 31, 2018 190,462 Granted 110,830 (1) Vested (101,109) (2) Forfeited (7,138) Balance at December 31, 2019 193,045 Granted 75,419 (1) Vested (78,010) (2) Forfeited (858) Balance at June 30, 2020 189,596 (1) The fair value per share on the grant date of February 13, 2020, January 8, 2020, and January 7, 2019 was $32.64, $31.49, and $24.85, respectively. (2) The Company repurchased and retired 33,119 and 28,504 restricted shares of common stock that vested during the six months ended June 30, 2020 and the year ended December 31, 2019, respectively. The weighted average grant date fair value of unvested restricted shares of common stock was $24.38 per share at January 1, 2020, $31.60 per share granted during the six months ended June 30, 2020, $23.11 per share vested during the six months ended June 30, 2020, $24.85 per share forfeited during the six months ended June 30, 2020, and $27.77 per share at June 30, 2020. The unrecognized compensation expense associated with the Company’s restricted shares of common stock at June 30, 2020 was approximately $4.2 million and is expected to be recognized over a weighted average period of approximately 2.7 years. The following table summarizes the fair value at vesting for the restricted shares of common stock that vested during the three and six months ended June 30, 2020 and 2019. Three months ended June 30, Six months ended June 30, Vested Restricted Shares of Common Stock 2020 2019 2020 2019 Vested restricted shares of common stock — — 78,010 78,431 Fair value of vested restricted shares of common stock (in thousands) $ — $ — $ 2,463 $ 1,951

Noncontrolling Interest

Noncontrolling Interest	6 Months Ended
	Jun. 30, 2020
Noncontrolling Interest [Abstract]
Noncontrolling Interest	Noncontrolling Interest The following table summarizes the activity for noncontrolling interest in the Company for the six months ended June 30, 2020 and the year ended December 31, 2019. Noncontrolling Interest LTIP Units Other Total Noncontrolling Interest Balance at December 31, 2018 1,616,200 2,453,234 4,069,434 3.5 % Granted/Issued 364,173 — 364,173 N/A Forfeited (16,618) — (16,618) N/A Conversions from LTIP units to Other Common Units (266,397) 266,397 — N/A Redemptions from Other Common Units to common stock — (680,137) (680,137) N/A Balance at December 31, 2019 1,697,358 2,039,494 3,736,852 2.5 % Granted/Issued 278,806 — 278,806 N/A Forfeited — — — N/A Conversions from LTIP units to Other Common Units (197,775) 197,775 — N/A Redemptions from Other Common Units to common stock — (447,730) (447,730) N/A Balance at June 30, 2020 1,778,389 1,789,539 3,567,928 2.3 % The weighted average grant date fair value of outstanding LTIP units was $21.64 per unit at January 1, 2020, $29.47 per unit granted during the six months ended June 30, 2020, $18.72 per unit converted during the six months ended June 30, 2020, and $23.19 per unit at June 30, 2020. LTIP Units LTIP units granted on January 8, 2020 to non-employee, independent directors, subject to the recipient’s continued service, will vest on January 1, 2021. LTIP units granted on January 8, 2020 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, 2020. Refer to Note 8 for a discussion of the LTIP units granted on January 8, 2020 pursuant to the January 6, 2017 performance units. 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 following table summarizes the assumptions used in valuing such LTIP units granted during the six months ended June 30, 2020 (excluding those LTIP units granted pursuant to the January 6, 2017 performance units; refer to Note 8 for details). LTIP Units Assumptions Grant date January 8, 2020 Expected term (years) 10 Expected volatility 18.0 % Expected dividend yield 5.75 % Risk-free interest rate 1.61 % Fair value of LTIP units at issuance (in thousands) $ 4,030 LTIP units at issuance 136,741 Fair value unit price per LTIP unit at issuance $ 29.47 The following table summarizes activity related to the Company’s unvested LTIP units for the six months ended June 30, 2020 and the year ended December 31, 2019. Unvested LTIP Units LTIP Units Balance at December 31, 2018 251,216 Granted 364,173 Vested (371,423) Forfeited (16,618) Balance at December 31, 2019 227,348 Granted 278,806 Vested (174,145) Forfeited — Balance at June 30, 2020 332,009 The weighted average grant date fair value of unvested LTIP units was $23.37 per unit at January 1, 2020, $29.47 per unit granted during the six months ended June 30, 2020, $26.38 per unit vested during the six months ended June 30, 2020, and $26.92 per unit at June 30, 2020. The unrecognized compensation expense associated with the Company’s LTIP units at June 30, 2020 was approximately $6.5 million and is expected to be recognized over a weighted average period of approximately 2.5 years. The following table summarizes the fair value at vesting for the LTIP units that vested during the three and six months ended June 30, 2020 and 2019. Three months ended June 30, Six months ended June 30, Vested LTIP units 2020 2019 2020 2019 Vested LTIP units 43,958 46,652 174,145 204,341 Fair value of vested LTIP units (in thousands) $ 1,213 $ 1,401 $ 5,074 $ 5,464

Equity Incentive Plan

Equity Incentive Plan	6 Months Ended
	Jun. 30, 2020
Share-based Payment Arrangement [Abstract]
Equity Incentive Plan	Equity Incentive Plan On January 8, 2020, 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 8, 2020 are substantially the same as the terms of the performance units granted on January 7, 2019, except that the measuring period commenced on January 1, 2020 and ends on December 31, 2022. 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 ratably from the grant date into earnings over the vesting period. The following table summarizes the assumptions used in valuing the performance units granted during the six months ended June 30, 2020. Performance Units Assumptions Grant date January 8, 2020 Expected volatility 17.4 % Expected dividend yield 5.75 % Risk-free interest rate 1.59 % Fair value of performance units grant (in thousands) $ 5,389 On December 31, 2019 the measuring period pursuant to the January 6, 2017 performance units concluded and it was determined that the Company’s total stockholder return exceeded the threshold percentage and return hurdle. The compensation committee of the board of directors approved the issuance of 76,096 vested LTIP units and 46,376 vested shares of common stock to the participants (of which 18,241 shares of common stock were repurchased and retired), which were issued on January 8, 2020. The compensation committee of the board of directors also approved the issuance of 65,969 LTIP units and 3,398 restricted shares of common stock that will vest on December 31, 2020, which were issued on January 8, 2020. The unrecognized compensation expense associated with the Company’s performance units at June 30, 2020 was approximately $8.6 million and is expected to be recognized over a weighted average period of approximately 2.0 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, and the Company’s director compensation for the three and six months ended June 30, 2020 and 2019. Three months ended June 30, Six months ended June 30, Non-Cash Compensation Expense (in thousands) 2020 2019 2020 2019 Restricted shares of common stock $ 481 $ 444 $ 948 $ 871 LTIP units 978 899 1,942 1,786 Performance units 1,341 1,096 2,648 1,955 Director compensation (1) 138 98 252 203 Total non-cash compensation expense $ 2,938 $ 2,537 $ 5,790 $ 4,815 (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 and six months ended June 30, 2020 and 2019. The number of shares of common stock granted is calculated based on the trailing ten days average common stock price ending on the third business day preceding the grant date.

Leases

Leases	6 Months Ended
	Jun. 30, 2020
Leases [Abstract]
Leases	Leases Lessor Leases The Company has operating leases in which it is the lessor for its rental property. Certain leases contain variable lease payments based upon changes in the Consumer Price Index (“CPI”). Certain leases contain options to renew or terminate the lease, and options for the lessee to purchase the rental property, all of which are predominately at the sole discretion of the lessee. The following table summarizes the components of rental income recognized during the three and six months ended June 30, 2020 and 2019 included in the accompanying Consolidated Statements of Operations. Three months ended June 30, Six months ended June 30, Rental Income (in thousands) 2020 2019 2020 2019 Fixed lease payments $ 91,234 $ 74,958 $ 181,630 $ 147,075 Variable lease payments 25,588 19,258 50,594 41,439 Straight-line rental income 1,823 3,292 5,750 5,576 Net decrease to rental income related to above and below market lease amortization (1,174) (1,146) (2,164) (2,113) Total rental income $ 117,471 $ 96,362 $ 235,810 $ 191,977 During the three and six months ended June 30, 2020 and 2019 the Company evaluated its operating leases and determined that the future collectability of six leases was not reasonably assured. As a result the Company converted to the cash basis of accounting for these leases which resulted in a reduction of rental income of approximately $1.2 million, $0.9 million, $0, and $0 for three and six months ended June 30, 2020 and 2019, respectively, due to the reversal of accrued rent. Additionally, there was $0.6 million, $0.6 million, $0, and $0 of contractual rental income that was not recognized for payments that were not received from the tenants for the three and six months ended June 30, 2020 and 2019, respectively. As of June 30, 2020 and December 31, 2019, the Company had accrued rental income of approximately $51.3 million and $44.3 million, respectively, included in tenant accounts receivable on the accompanying Consolidated Balance Sheets. As of June 30, 2020 and December 31, 2019, the Company had approximately $28.2 million and $22.6 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 June 30, 2020 and December 31, 2019, the Company had 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. The Company’s remaining lease security deposits are commingled in cash and cash equivalents. These funds may be used to settle tenant accounts receivables in the event of a default under the related lease. As of June 30, 2020 and December 31, 2019, the Company’s total liability associated with these lease security deposits was approximately $10.0 million and $9.8 million, respectively, and is included in tenant prepaid rent and security deposits on the accompanying Consolidated Balance Sheets. The Company estimates that billings for 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, was approximately $4.9 million, $9.7 million, $4.1 million and $8.0 million for the three and six months ended June 30, 2020 and 2019, 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. The following table summarizes the maturity of fixed lease payments under the Company’s leases as of June 30, 2020. Year Maturity of Fixed Lease Payments (in thousands) Remainder of 2020 $ 183,554 2021 $ 344,763 2022 $ 307,910 2023 $ 265,262 2024 $ 221,533 Thereafter $ 846,338 Lessee Leases The Company has operating leases in which it is the lessee for ground leases and its corporate office lease. These leases have remaining lease terms of approximately 6.0 years to 46.5 years. Certain ground leases contain options to extend the leases for ten years to 20 years, all of which are reasonably certain to be exercised, and are included in the computation of the Company’s right-of-use assets and operating lease liabilities. The following table summarizes supplemental information related to operating lease right-of-use assets and operating lease liabilities recognized in the Company’s Consolidated Balance Sheets as of June 30, 2020 and December 31, 2019. Operating Lease Term and Discount Rate June 30, 2020 December 31, 2019 Weighted average remaining lease term (years) 27.0 36.0 Weighted average discount rate 6.8 % 7.1 % The following table summarizes the operating lease cost recognized during the three and six months ended June 30, 2020 and 2019 included in the Company’s Consolidated Statements of Operations. Three months ended June 30, Six months ended June 30, Operating Lease Cost (in thousands) 2020 2019 2020 2019 Operating lease cost included in property expense attributable to ground leases $ 331 $ 331 $ 662 $ 662 Operating lease cost included in general and administrative expense attributable to corporate office lease 423 267 741 533 Total operating lease cost $ 754 $ 598 $ 1,403 $ 1,195 The following table summarizes supplemental cash flow information related to operating leases recognized during the six months ended June 30, 2020 and 2019 in the Company’s Consolidated Statements of Cash Flows. Six months ended June 30, Operating Leases (in thousands) 2020 2019 Cash paid for amounts included in the measurement of lease liabilities (operating cash flows) $ 1,143 $ 1,141 Right-of-use assets obtained in exchange for new lease liabilities $ 7,718 $ — The following table summarizes the maturity of operating lease liabilities under the Company’s ground leases and corporate office lease as of June 30, 2020. Year Maturity of Operating Lease Liabilities (1) (in thousands) Remainder of 2020 $ 1,150 2021 2,102 2022 2,975 2023 3,021 2024 3,064 Thereafter 50,017 Total lease payments 62,329 Less: Imputed interest (38,050) Present value of operating lease liabilities $ 24,279 (1) Operating lease liabilities do not include estimates of CPI rent changes required by certain ground lease agreements. Therefore, actual payments may differ than those presented.
Leases	Leases Lessor Leases The Company has operating leases in which it is the lessor for its rental property. Certain leases contain variable lease payments based upon changes in the Consumer Price Index (“CPI”). Certain leases contain options to renew or terminate the lease, and options for the lessee to purchase the rental property, all of which are predominately at the sole discretion of the lessee. The following table summarizes the components of rental income recognized during the three and six months ended June 30, 2020 and 2019 included in the accompanying Consolidated Statements of Operations. Three months ended June 30, Six months ended June 30, Rental Income (in thousands) 2020 2019 2020 2019 Fixed lease payments $ 91,234 $ 74,958 $ 181,630 $ 147,075 Variable lease payments 25,588 19,258 50,594 41,439 Straight-line rental income 1,823 3,292 5,750 5,576 Net decrease to rental income related to above and below market lease amortization (1,174) (1,146) (2,164) (2,113) Total rental income $ 117,471 $ 96,362 $ 235,810 $ 191,977 During the three and six months ended June 30, 2020 and 2019 the Company evaluated its operating leases and determined that the future collectability of six leases was not reasonably assured. As a result the Company converted to the cash basis of accounting for these leases which resulted in a reduction of rental income of approximately $1.2 million, $0.9 million, $0, and $0 for three and six months ended June 30, 2020 and 2019, respectively, due to the reversal of accrued rent. Additionally, there was $0.6 million, $0.6 million, $0, and $0 of contractual rental income that was not recognized for payments that were not received from the tenants for the three and six months ended June 30, 2020 and 2019, respectively. As of June 30, 2020 and December 31, 2019, the Company had accrued rental income of approximately $51.3 million and $44.3 million, respectively, included in tenant accounts receivable on the accompanying Consolidated Balance Sheets. As of June 30, 2020 and December 31, 2019, the Company had approximately $28.2 million and $22.6 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 June 30, 2020 and December 31, 2019, the Company had 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. The Company’s remaining lease security deposits are commingled in cash and cash equivalents. These funds may be used to settle tenant accounts receivables in the event of a default under the related lease. As of June 30, 2020 and December 31, 2019, the Company’s total liability associated with these lease security deposits was approximately $10.0 million and $9.8 million, respectively, and is included in tenant prepaid rent and security deposits on the accompanying Consolidated Balance Sheets. The Company estimates that billings for 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, was approximately $4.9 million, $9.7 million, $4.1 million and $8.0 million for the three and six months ended June 30, 2020 and 2019, 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. The following table summarizes the maturity of fixed lease payments under the Company’s leases as of June 30, 2020. Year Maturity of Fixed Lease Payments (in thousands) Remainder of 2020 $ 183,554 2021 $ 344,763 2022 $ 307,910 2023 $ 265,262 2024 $ 221,533 Thereafter $ 846,338 Lessee Leases The Company has operating leases in which it is the lessee for ground leases and its corporate office lease. These leases have remaining lease terms of approximately 6.0 years to 46.5 years. Certain ground leases contain options to extend the leases for ten years to 20 years, all of which are reasonably certain to be exercised, and are included in the computation of the Company’s right-of-use assets and operating lease liabilities. The following table summarizes supplemental information related to operating lease right-of-use assets and operating lease liabilities recognized in the Company’s Consolidated Balance Sheets as of June 30, 2020 and December 31, 2019. Operating Lease Term and Discount Rate June 30, 2020 December 31, 2019 Weighted average remaining lease term (years) 27.0 36.0 Weighted average discount rate 6.8 % 7.1 % The following table summarizes the operating lease cost recognized during the three and six months ended June 30, 2020 and 2019 included in the Company’s Consolidated Statements of Operations. Three months ended June 30, Six months ended June 30, Operating Lease Cost (in thousands) 2020 2019 2020 2019 Operating lease cost included in property expense attributable to ground leases $ 331 $ 331 $ 662 $ 662 Operating lease cost included in general and administrative expense attributable to corporate office lease 423 267 741 533 Total operating lease cost $ 754 $ 598 $ 1,403 $ 1,195 The following table summarizes supplemental cash flow information related to operating leases recognized during the six months ended June 30, 2020 and 2019 in the Company’s Consolidated Statements of Cash Flows. Six months ended June 30, Operating Leases (in thousands) 2020 2019 Cash paid for amounts included in the measurement of lease liabilities (operating cash flows) $ 1,143 $ 1,141 Right-of-use assets obtained in exchange for new lease liabilities $ 7,718 $ — The following table summarizes the maturity of operating lease liabilities under the Company’s ground leases and corporate office lease as of June 30, 2020. Year Maturity of Operating Lease Liabilities (1) (in thousands) Remainder of 2020 $ 1,150 2021 2,102 2022 2,975 2023 3,021 2024 3,064 Thereafter 50,017 Total lease payments 62,329 Less: Imputed interest (38,050) Present value of operating lease liabilities $ 24,279 (1) Operating lease liabilities do not include estimates of CPI rent changes required by certain ground lease agreements. Therefore, actual payments may differ than those presented.

Earnings Per Share

Earnings Per Share	6 Months Ended
	Jun. 30, 2020
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Share During the three and six months ended June 30, 2020 and 2019, there were 189,895, 185,821, 220,482 and 217,187, respectively, of unvested restricted shares of common stock on a weighted average basis that were considered participating securities. The following table reconciles the numerators and denominators in the computation of basic and diluted earnings per common share for the three and six months ended June 30, 2020 and 2019. Three months ended June 30, Six months ended June 30, Earnings Per Share (in thousands, except per share data) 2020 2019 2020 2019 Numerator Net income attributable to common stockholders $ 17,552 $ 12,394 $ 79,635 $ 18,201 Denominator Weighted average common shares outstanding — basic 148,663 125,251 148,116 120,015 Effect of dilutive securities (1) Share-based compensation 364 309 225 291 Shares issuable under forward sales agreements — — — — Weighted average common shares outstanding — diluted 149,027 125,560 148,341 120,306 Net income per share — basic and diluted Net income per share attributable to common stockholders — basic $ 0.12 $ 0.10 $ 0.54 $ 0.15 Net income per share attributable to common stockholders — diluted $ 0.12 $ 0.10 $ 0.54 $ 0.15

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2020
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and ContingenciesThe 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 $3.0 million as of June 30, 2020 related to construction projects and certain other agreements.

Subsequent Events

Subsequent Events	6 Months Ended
	Jun. 30, 2020
Subsequent Events [Abstract]
Subsequent Events	Subsequent EventsThere were no recognized or non-recognized subsequent events.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2020
Accounting Policies [Abstract]
Quarterly Financial Information	Interim Financial Information The accompanying interim financial statements have been presented in conformity with accounting principles generally accepted in the United States of America (“GAAP”) and with the instructions to Form 10-Q and Regulation S-X for interim financial information. Accordingly, these statements do not include all of the information and notes required by GAAP for complete financial statements. In the opinion of management, the accompanying interim financial statements include all adjustments, consisting of normal recurring items, necessary for their fair statement in conformity with GAAP. Interim results are not necessarily indicative of results for a full year. The year-end consolidated balance sheet data was derived from audited financial statements, but does not include all disclosures required by GAAP. The information included in this Quarterly Report on Form 10-Q should be read in conjunction with the Company’s consolidated financial statements and notes thereto contained in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2019.
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 and restated (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.
New Accounting Pronouncements	New Accounting Standards In March 2020, the Financial Accounting Standards Board issued Accounting Standards Update (“ASU”) 2020-04, Reference Rate Reform (Topic 848)

Summary of Significant Accoun_3

Summary of Significant Accounting Policies - Cash, Cash Equivalents and Restricted Cash (Tables)	6 Months Ended
	Jun. 30, 2020
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. Reconciliation of cash and cash equivalents and restricted cash (in thousands) June 30, 2020 December 31, 2019 Cash and cash equivalents $ 102,097 $ 9,041 Restricted cash 12,505 2,823 Total cash and cash equivalents and restricted cash $ 114,602 $ 11,864

Rental Property (Tables)

Rental Property (Tables)	6 Months Ended
	Jun. 30, 2020
Real Estate [Abstract]
Schedule of components of rental property	The following table summarizes the components of rental property as of June 30, 2020 and December 31, 2019. Rental Property (in thousands) June 30, 2020 December 31, 2019 Land $ 444,489 $ 435,923 Buildings, net of accumulated depreciation of $292,467 and $254,458, respectively 2,833,458 2,787,234 Tenant improvements, net of accumulated depreciation of $23,724 and $21,487, respectively 38,638 38,339 Building and land improvements, net of accumulated depreciation of $130,170 and $111,688, respectively 239,214 232,456 Construction in progress 30,660 29,406 Deferred leasing intangibles, net of accumulated amortization of $267,553 and $241,304, respectively 451,738 475,149 Total rental property, net $ 4,038,197 $ 3,998,507
Schedule of real estate properties acquired	The following table summarizes the acquisitions of the Company during the three and six months ended June 30, 2020. Market (1) Date Acquired Square Feet Buildings Purchase Price Detroit, MI January 10, 2020 491,049 1 $ 29,543 Rochester, NY January 10, 2020 124,850 1 8,565 Minneapolis/St Paul, MN February 6, 2020 139,875 1 10,460 Sacramento, CA February 6, 2020 160,534 1 18,468 Richmond, VA February 6, 2020 78,128 1 5,481 Milwaukee/Madison, WI February 7, 2020 81,230 1 7,219 Detroit, MI February 11, 2020 311,123 1 23,141 Philadelphia, PA March 9, 2020 78,000 1 6,571 Tulsa, OK March 9, 2020 134,600 1 9,895 Three months ended March 31, 2020 1,599,389 9 119,343 Sacramento, CA June 11, 2020 54,463 1 5,730 Chicago, IL June 29, 2020 67,817 1 6,184 Three months ended June 30, 2020 122,280 2 11,914 Six months ended June 30, 2020 1,721,669 11 $ 131,257 (1) As defined by CoStar Realty Information Inc (“CoStar”). If the building is located outside of a CoStar defined market, the city and state is reflected.
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 six months ended June 30, 2020 for the acquired assets and liabilities in connection with the acquisitions identified in the table above. Acquired Assets and Liabilities Purchase Price (in thousands) Weighted Average Amortization Period (years) of Intangibles at Acquisition Land $ 10,498 N/A Buildings 92,860 N/A Tenant improvements 1,535 N/A Building and land improvements 4,670 N/A Construction in progress 669 N/A Other assets 450 N/A Deferred leasing intangibles - In-place leases 14,963 7.9 Deferred leasing intangibles - Tenant relationships 7,115 11.1 Deferred leasing intangibles - Above market leases 1,069 6.3 Deferred leasing intangibles - Below market leases (2,572) 5.4 Total purchase price $ 131,257
Schedule of pro forma information for acquired properties	The following table summarizes the results of operations for the three and six months ended June 30, 2020 for the buildings acquired during the six months ended June 30, 2020 included in the Company’s Consolidated Statements of Operations from the date of acquisition. Results of Operations (in thousands) Three months ended June 30, 2020 Six months ended June 30, 2020 Total revenue $ 2,807 $ 4,748 Net income $ 609 $ 861
Schedule of Finite-Lived Intangible Assets and Below Market Leases	The following table summarizes the deferred leasing intangibles on the accompanying Consolidated Balance Sheets as of June 30, 2020 and December 31, 2019. June 30, 2020 December 31, 2019 Deferred Leasing Intangibles (in thousands) Gross Accumulated Amortization Net Gross Accumulated Amortization Net Above market leases $ 92,793 $ (36,413) $ 56,380 $ 92,607 $ (32,115) $ 60,492 Other intangible lease assets 626,498 (231,140) 395,358 623,846 (209,189) 414,657 Total deferred leasing intangible assets $ 719,291 $ (267,553) $ 451,738 $ 716,453 $ (241,304) $ 475,149 Below market leases $ 39,409 $ (13,117) $ 26,292 $ 38,802 $ (12,064) $ 26,738 Total deferred leasing intangible liabilities $ 39,409 $ (13,117) $ 26,292 $ 38,802 $ (12,064) $ 26,738 The following table summarizes the amortization expense and the net decrease to rental income for the amortization of deferred leasing intangibles during the three and six months ended June 30, 2020 and 2019. Three months ended June 30, Six months ended June 30, Deferred Leasing Intangibles Amortization (in thousands) 2020 2019 2020 2019 Net decrease to rental income related to above and below market lease amortization $ 1,174 $ 1,146 $ 2,164 $ 2,113 Amortization expense related to other intangible lease assets $ 21,076 $ 17,899 $ 41,378 $ 34,713
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense	The following table summarizes the amortization of deferred leasing intangibles over the next five calendar years beginning with 2020 as of June 30, 2020. 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 2020 $ 36,982 $ 1,827 2021 $ 65,116 $ 2,717 2022 $ 55,459 $ 2,190 2023 $ 46,930 $ 2,395 2024 $ 38,019 $ 2,703
Below Market Lease, Future Amortization Income	The following table summarizes the amortization of deferred leasing intangibles over the next five calendar years beginning with 2020 as of June 30, 2020. 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 2020 $ 36,982 $ 1,827 2021 $ 65,116 $ 2,717 2022 $ 55,459 $ 2,190 2023 $ 46,930 $ 2,395 2024 $ 38,019 $ 2,703

Debt (Tables)

Debt (Tables)	6 Months Ended
	Jun. 30, 2020
Debt Disclosure [Abstract]
Summary of the mortgage notes payable, unsecured term loans and credit facility	The following table summarizes the Company’s outstanding indebtedness, including borrowings under the Company’s unsecured credit facility, unsecured term loans, unsecured notes, and mortgage notes as of June 30, 2020 and December 31, 2019. Loan Principal Outstanding as of June 30, 2020 (in thousands) Principal Outstanding as of December 31, 2019 (in thousands) Interest Rate (1)(2) Maturity Date Prepayment Terms (3) Unsecured credit facility: Unsecured Credit Facility (4) $ — $ 146,000 L + 0.90% January 12, 2024 i Total unsecured credit facility — 146,000 Unsecured term loans: Unsecured Term Loan C (5) — 150,000 2.39 % September 29, 2020 i Unsecured Term Loan B (5) — 150,000 3.05 % March 21, 2021 i Unsecured Term Loan A 150,000 150,000 3.38 % March 31, 2022 i Unsecured Term Loan D 150,000 150,000 2.85 % January 4, 2023 i Unsecured Term Loan G (6) 300,000 — 3.31 % April 18, 2023 i Unsecured Term Loan E 175,000 175,000 3.92 % January 15, 2024 i Unsecured Term Loan F 200,000 100,000 L + 1.00% January 12, 2025 i Total unsecured term loans 975,000 875,000 Less: Total unamortized deferred financing fees and debt issuance costs (4,718) (3,625) Total carrying value unsecured term loans, net 970,282 871,375 Unsecured notes: Series F Unsecured Notes 100,000 100,000 3.98 % January 5, 2023 ii Series A Unsecured Notes 50,000 50,000 4.98 % October 1, 2024 ii Series D Unsecured Notes 100,000 100,000 4.32 % February 20, 2025 ii Series G Unsecured Notes 75,000 75,000 4.10 % June 13, 2025 ii Series B Unsecured Notes 50,000 50,000 4.98 % July 1, 2026 ii Series C Unsecured Notes 80,000 80,000 4.42 % December 30, 2026 ii Series E Unsecured Notes 20,000 20,000 4.42 % February 20, 2027 ii Series H Unsecured Notes 100,000 100,000 4.27 % June 13, 2028 ii Total unsecured notes 575,000 575,000 Less: Total unamortized deferred financing fees and debt issuance costs (1,918) (2,117) Total carrying value unsecured notes, net 573,082 572,883 Mortgage notes (secured debt): Wells Fargo Bank, National Association CMBS Loan 49,473 51,406 4.31 % December 1, 2022 iii Thrivent Financial for Lutherans 3,619 3,679 4.78 % December 15, 2023 iv Total mortgage notes 53,092 55,085 Add: Total unamortized fair market value premiums 34 39 Less: Total unamortized deferred financing fees and debt issuance costs (299) (369) Total carrying value mortgage notes, net 52,827 54,755 Total / weighted average interest rate (7) $ 1,596,191 $ 1,645,013 3.48 % (1) Interest rate as of June 30, 2020. At June 30, 2020, the one-month LIBOR (“L”) was 0.16225%. The current interest rate is not adjusted to include the amortization of deferred financing fees or debt issuance costs incurred in obtaining debt or any unamortized fair market value premiums. The spread over the applicable rate for the Company’s unsecured credit facility and unsecured term loans is based on the Company’s debt rating, as defined in the respective loan agreements. (2) The unsecured term loans have a stated interest rate of one-month LIBOR plus a spread of 1.0%, with the exception of the Unsecured Term Loan G which has a spread of 1.5% and is subject to a minimum rate for LIBOR of 0.25%. As of June 30, 2020, one-month LIBOR for the Unsecured Term Loans A, D, E, and G was swapped to a fixed rate of 2.38%, 1.85%, 2.92%, and 1.72%, respectively. One-month LIBOR for the Unsecured Term Loan F was swapped to a fixed rate of 2.11% effective July 15, 2020. One-month LIBOR for the Unsecured Term Loan G will be swapped to a fixed rate of 1.17% effective September 29, 2020 and 0.28% effective March 19, 2021. (3) 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; and (iv) pre-payable without penalty three months prior to the maturity date. (4) The capacity of the unsecured credit facility is $500.0 million. Deferred financing fees and debt issuance costs, net of accumulated amortization related to the unsecured credit facility of approximately $2.0 million and $2.4 million is included in prepaid expenses and other assets on the accompanying Consolidated Balance Sheets as of June 30, 2020 and December 31, 2019, respectively. The initial maturity date is January 15, 2023, which may be extended pursuant to two six (5) The Unsecured Term Loan B and the Unsecured Term Loan C were paid in full on April 17, 2020 in connection with the execution of the Unsecured Term Loan G. (6) The initial maturity date is April 16, 2021, which may be extended pursuant to two one-year extension options exercisable by the Company in its discretion upon advance written notice. Exercise of each one-year option is subject to the following conditions: (i) absence of a default immediately before the extension and immediately after giving effect to the extension, (ii) accuracy of representations and warranties as of the extension date (both immediately before and after the extension), as if made on the extension date, and (iii) payment of a fee. Neither extension option is subject to lender consent, assuming proper notice and satisfaction of the conditions. (7) The weighted average interest rate was calculated using the fixed interest rate swapped on the notional amount of $775.0 million of debt, and is not adjusted to include the amortization of deferred financing fees or debt issuance costs incurred in obtaining debt or any unamortized fair market value premiums.
Interest Income and Interest Expense Disclosure [Table Text Block]	The following table summarizes the costs included in interest expense related to the Company’s debt arrangements on the accompanying Consolidated Statement of Operations for the three and six months ended June 30, 2020 and 2019. Three months ended June 30, Six months ended June 30, Costs Included in Interest Expense (in thousands) 2020 2019 2020 2019 Amortization of deferred financing fees and debt issuance costs and fair market value premiums $ 746 $ 618 $ 1,422 $ 1,236 Facility, unused, and other fees $ 316 $ 387 $ 680 $ 770
Schedule of aggregate carrying value of the debt and the corresponding estimate of fair value	The following table summarizes the aggregate principal outstanding under the Company’s debt arrangements and the corresponding estimate of fair value as of June 30, 2020 and December 31, 2019. June 30, 2020 December 31, 2019 Indebtedness (in thousands) Principal Outstanding Fair Value Principal Outstanding Fair Value Unsecured credit facility $ — $ — $ 146,000 $ 146,000 Unsecured term loans 975,000 964,497 875,000 875,000 Unsecured notes 575,000 617,073 575,000 614,493 Mortgage notes 53,092 55,227 55,085 56,021 Total principal amount 1,603,092 $ 1,636,797 1,651,085 $ 1,691,514 Add: Total unamortized fair market value premiums 34 39 Less: Total unamortized deferred financing fees and debt issuance costs (6,935) (6,111) Total carrying value $ 1,596,191 $ 1,645,013

Derivative Financial Instrume_2

Derivative Financial Instruments (Tables)	6 Months Ended
	Jun. 30, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Derivative Instruments [Table Text Block]	The following table summarizes the Company’s outstanding interest rate swaps as of June 30, 2020. All of the Company’s interest rate swaps are designated as qualifying cash flow hedges. Interest Rate Trade Date Effective Date Notional Amount Fair Value Pay Fixed Interest Rate Receive Variable Interest Rate Maturity Date The Toronto-Dominion Bank Oct-14-2015 Sep-29-2016 $ 25,000 $ (76) 1.3830 % One-month L Sep-29-2020 PNC Bank, N.A. Oct-14-2015 Sep-29-2016 $ 50,000 $ (153) 1.3906 % One-month L Sep-29-2020 Regions Bank Oct-14-2015 Sep-29-2016 $ 35,000 $ (106) 1.3858 % One-month L Sep-29-2020 U.S. Bank, N.A. Oct-14-2015 Sep-29-2016 $ 25,000 $ (77) 1.3950 % One-month L Sep-29-2020 Capital One, N.A. Oct-14-2015 Sep-29-2016 $ 15,000 $ (46) 1.3950 % One-month L Sep-29-2020 Royal Bank of Canada Jan-08-2015 Mar-20-2015 $ 25,000 $ (280) 1.7090 % One-month L Mar-21-2021 The Toronto-Dominion Bank Jan-08-2015 Mar-20-2015 $ 25,000 $ (280) 1.7105 % One-month L Mar-21-2021 The Toronto-Dominion Bank Jan-08-2015 Sep-10-2017 $ 100,000 $ (1,493) 2.2255 % One-month L Mar-21-2021 Wells Fargo, N.A. Jan-08-2015 Mar-20-2015 $ 25,000 $ (750) 1.8280 % One-month L Mar-31-2022 The Toronto-Dominion Bank Jan-08-2015 Feb-14-2020 $ 25,000 $ (1,027) 2.4535 % One-month L Mar-31-2022 Regions Bank Jan-08-2015 Feb-14-2020 $ 50,000 $ (2,072) 2.4750 % One-month L Mar-31-2022 Capital One, N.A. Jan-08-2015 Feb-14-2020 $ 50,000 $ (2,121) 2.5300 % One-month L Mar-31-2022 The Toronto-Dominion Bank Jul-20-2017 Oct-30-2017 $ 25,000 $ (1,093) 1.8485 % One-month L Jan-04-2023 Royal Bank of Canada Jul-20-2017 Oct-30-2017 $ 25,000 $ (1,094) 1.8505 % One-month L Jan-04-2023 Wells Fargo, N.A. Jul-20-2017 Oct-30-2017 $ 25,000 $ (1,094) 1.8505 % One-month L Jan-04-2023 PNC Bank, N.A. Jul-20-2017 Oct-30-2017 $ 25,000 $ (1,093) 1.8485 % One-month L Jan-04-2023 PNC Bank, N.A. Jul-20-2017 Oct-30-2017 $ 50,000 $ (2,184) 1.8475 % One-month L Jan-04-2023 The Toronto-Dominion Bank Apr-20-2020 Sep-29-2020 $ 75,000 $ (290) 0.2750 % One-month L Apr-18-2023 Wells Fargo, N.A. Apr-20-2020 Sep-29-2020 $ 75,000 $ (298) 0.2790 % One-month L Apr-18-2023 The Toronto-Dominion Bank Apr-20-2020 Mar-19-2021 $ 75,000 $ (251) 0.2750 % One-month L Apr-18-2023 Wells Fargo, N.A. Apr-20-2020 Mar-19-2021 $ 75,000 $ (258) 0.2800 % One-month L Apr-18-2023 The Toronto-Dominion Bank Jul-24-2018 Jul-26-2019 $ 50,000 $ (4,932) 2.9180 % One-month L Jan-12-2024 PNC Bank, N.A. Jul-24-2018 Jul-26-2019 $ 50,000 $ (4,932) 2.9190 % One-month L Jan-12-2024 Bank of Montreal Jul-24-2018 Jul-26-2019 $ 50,000 $ (4,932) 2.9190 % One-month L Jan-12-2024 U.S. Bank, N.A. Jul-24-2018 Jul-26-2019 $ 25,000 $ (2,466) 2.9190 % One-month L Jan-12-2024 Wells Fargo, N.A. May-02-2019 Jul-15-2020 $ 50,000 $ (4,633) 2.2460 % One-month L Jan-15-2025 U.S. Bank, N.A. May-02-2019 Jul-15-2020 $ 50,000 $ (4,632) 2.2459 % One-month L Jan-15-2025 Regions Bank May-02-2019 Jul-15-2020 $ 50,000 $ (4,632) 2.2459 % One-month L Jan-15-2025 Bank of Montreal Jul-16-2019 Jul-15-2020 $ 50,000 $ (3,436) 1.7165 % One-month L Jan-15-2025
Schedule of interest rate swaps	The following table summarizes the fair value of the interest rate swaps outstanding as of June 30, 2020 and December 31, 2019. Balance Sheet Line Item (in thousands) Notional Amount June 30, 2020 Fair Value June 30, 2020 Notional Amount December 31, 2019 Fair Value December 31, 2019 Interest rate swaps-Asset $ — $ — $ 250,000 $ 303 Interest rate swaps-Liability $ 1,275,000 $ (50,731) $ 850,000 $ (18,819)
Schedule of the location in the financial statements of the gain or loss recognized on interest rate swaps	The following table summarizes the effect of cash flow hedge accounting and the location in the consolidated financial statements for the three and six months ended June 30, 2020 and 2019. Three months ended June 30, Six months ended June 30, Effect of Cash Flow Hedge Accounting (in thousands) 2020 2019 2020 2019 Loss recognized in accumulated other comprehensive loss on interest rate swaps $ 5,249 $ 14,946 $ 36,336 $ 20,802 Income (loss) reclassified from accumulated other comprehensive loss into income as interest expense $ (3,240) $ 1,082 $ (4,136) $ 2,204 Total interest expense presented in the Consolidated Statements of Operations in which the effects of cash flow hedges are recorded $ 15,333 $ 12,193 $ 30,197 $ 25,027
Schedule of financial instruments accounted for at fair value on a recurring basis	The following table summarizes the Company’s financial instruments that are accounted for at fair value on a recurring basis as of June 30, 2020 and December 31, 2019. Fair Value Measurements as of June 30, 2020 Using Balance Sheet Line Item (in thousands) Fair Value June 30, 2020 Level 1 Level 2 Level 3 Interest rate swaps-Asset $ — $ — $ — $ — Interest rate swaps-Liability $ (50,731) $ — $ (50,731) $ — Fair Value Measurements as of December 31, 2019 Using Balance Sheet Line Item (in thousands) Fair Value December 31, 2019 Level 1 Level 2 Level 3 Interest rate swaps-Asset $ 303 $ — $ 303 $ — Interest rate swaps-Liability $ (18,819) $ — $ (18,819) $ —

Equity (Tables)

Equity (Tables)	6 Months Ended
	Jun. 30, 2020
Stockholders' Equity Note [Abstract]
Schedule of Stock by Class	The following table summarizes the Company’s outstanding preferred stock issuances as of June 30, 2020. Preferred Stock Issuances Issuance Date Number of Shares Liquidation Value Per Share Interest Rate 6.875% Series C Cumulative Redeemable Preferred Stock ("Series C Preferred Stock") March 17, 2016 3,000,000 $ 25.00 6.875 %
Dividends Declared [Table Text Block]	The following tables summarize the dividends attributable to the Company’s outstanding preferred stock issuances during the six months ended June 30, 2020 and the year ended December 31, 2019. Quarter Ended 2020 Declaration Date Series C Payment Date June 30 April 9, 2020 $ 0.4296875 June 30, 2020 March 31 January 8, 2020 0.4296875 March 31, 2020 Total $ 0.8593750 Quarter Ended 2019 Declaration Date Series C Payment Date December 31 October 15, 2019 $ 0.4296875 December 31, 2019 September 30 July 15, 2019 0.4296875 September 30, 2019 June 30 April 9, 2019 0.4296875 July 1, 2019 March 31 January 10, 2019 0.4296875 April 1, 2019 Total $ 1.7187500
Schedule of stock sale activity	The following table summarizes the terms of the Company’s at-the market (“ATM”) common stock offering program as of June 30, 2020. ATM Common Stock Offering Program Date Maximum Aggregate Offering Price (in thousands) Aggregate Common Stock Available as of June 30, 2020 (in thousands) 2019 $600 million ATM February 14, 2019 $ 600,000 $ 318,248 The table below summarizes the activity under the ATM common stock offering program during the year ended December 31, 2019 (in thousands, except share data). There was no activity under the ATM common stock offering program during the six months ended June 30, 2020. Year ended December 31, 2019 ATM Common Stock Offering Program Shares Weighted Average Price Per Share Net 2019 $600 million ATM 9,711,706 $ 29.01 $ 279,156 Total/weighted average 9,711,706 $ 29.01 $ 279,156 On January 13, 2020, the Company completed an underwritten public offering of an aggregate 10,062,500 shares of common stock at a price to the underwriters of $30.9022 per share, consisting of (i) 5,600,000 shares offered directly by the Company and (ii) 4,462,500 shares offered by the forward dealer in connection with certain forward sale agreements (including 1,312,500 shares offered pursuant to the underwriters’ option to purchase additional shares, which option was exercised in full). The offering closed on January 16, 2020 and the Company received net proceeds from the sale of shares offered directly by the Company of approximately $173.1 million. Subject to the Company’s right to elect cash or net share settlement, the Company has the ability to settle the forward sales agreements at any time through scheduled maturity date of the forward sale agreements of January 13, 2021.
Common Stock Dividends Declared [Table Text Block]	The following tables summarize the dividends attributable to the Company’s outstanding shares of common stock that were declared during the six months ended June 30, 2020 and the year ended December 31, 2019. Month Ended 2020 Declaration Date Record Date Per Share Payment Date June 30 April 9, 2020 June 30, 2020 $ 0.12 July 15, 2020 May 31 April 9, 2020 May 29, 2020 0.12 June 15, 2020 April 30 April 9, 2020 April 30, 2020 0.12 May 15, 2020 March 31 January 8, 2020 March 31, 2020 0.12 April 15, 2020 February 29 January 8, 2020 February 28, 2020 0.12 March 16, 2020 January 31 January 8, 2020 January 31, 2020 0.12 February 18, 2020 Total $ 0.72 Month Ended 2019 Declaration Date Record Date Per Share Payment Date December 31 October 15, 2019 December 31, 2019 $ 0.119167 January 15, 2020 November 30 October 15, 2019 November 29, 2019 0.119167 December 16, 2019 October 31 October 15, 2019 October 31, 2019 0.119167 November 15, 2019 September 30 July 15, 2019 September 30, 2019 0.119167 October 15, 2019 August 31 July 15, 2019 August 30, 2019 0.119167 September 16, 2019 July 31 July 15, 2019 July 31, 2019 0.119167 August 15, 2019 June 30 April 9, 2019 June 28, 2019 0.119167 July 15, 2019 May 31 April 9, 2019 May 31, 2019 0.119167 June 17, 2019 April 30 April 9, 2019 April 30, 2019 0.119167 May 15, 2019 March 31 January 10, 2019 March 29, 2019 0.119167 April 15, 2019 February 28 January 10, 2019 February 28, 2019 0.119167 March 15, 2019 January 31 January 10, 2019 January 31, 2019 0.119167 February 15, 2019 Total $ 1.430004
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 six months ended June 30, 2020 and the year ended December 31, 2019. Unvested Restricted Shares of Common Stock Shares Balance at December 31, 2018 190,462 Granted 110,830 (1) Vested (101,109) (2) Forfeited (7,138) Balance at December 31, 2019 193,045 Granted 75,419 (1) Vested (78,010) (2) Forfeited (858) Balance at June 30, 2020 189,596 (1) The fair value per share on the grant date of February 13, 2020, January 8, 2020, and January 7, 2019 was $32.64, $31.49, and $24.85, respectively. (2) The Company repurchased and retired 33,119 and 28,504 restricted shares of common stock that vested during the six months ended June 30, 2020 and the year ended December 31, 2019, 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 and six months ended June 30, 2020 and 2019. Three months ended June 30, Six months ended June 30, Vested Restricted Shares of Common Stock 2020 2019 2020 2019 Vested restricted shares of common stock — — 78,010 78,431 Fair value of vested restricted shares of common stock (in thousands) $ — $ — $ 2,463 $ 1,951

Noncontrolling Interest (Tables

Noncontrolling Interest (Tables)	6 Months Ended
	Jun. 30, 2020
Noncontrolling Interest [Abstract]
Noncontrolling interest activity	The following table summarizes the activity for noncontrolling interest in the Company for the six months ended June 30, 2020 and the year ended December 31, 2019. Noncontrolling Interest LTIP Units Other Total Noncontrolling Interest Balance at December 31, 2018 1,616,200 2,453,234 4,069,434 3.5 % Granted/Issued 364,173 — 364,173 N/A Forfeited (16,618) — (16,618) N/A Conversions from LTIP units to Other Common Units (266,397) 266,397 — N/A Redemptions from Other Common Units to common stock — (680,137) (680,137) N/A Balance at December 31, 2019 1,697,358 2,039,494 3,736,852 2.5 % Granted/Issued 278,806 — 278,806 N/A Forfeited — — — N/A Conversions from LTIP units to Other Common Units (197,775) 197,775 — N/A Redemptions from Other Common Units to common stock — (447,730) (447,730) N/A Balance at June 30, 2020 1,778,389 1,789,539 3,567,928 2.3 %
Schedule of share-based payment award, LTIP unit awards, valuation assumptions	The following table summarizes the assumptions used in valuing such LTIP units granted during the six months ended June 30, 2020 (excluding those LTIP units granted pursuant to the January 6, 2017 performance units; refer to Note 8 for details). LTIP Units Assumptions Grant date January 8, 2020 Expected term (years) 10 Expected volatility 18.0 % Expected dividend yield 5.75 % Risk-free interest rate 1.61 % Fair value of LTIP units at issuance (in thousands) $ 4,030 LTIP units at issuance 136,741 Fair value unit price per LTIP unit at issuance $ 29.47
Schedule of activity related to unvested LTIP unit awards	The following table summarizes activity related to the Company’s unvested LTIP units for the six months ended June 30, 2020 and the year ended December 31, 2019. Unvested LTIP Units LTIP Units Balance at December 31, 2018 251,216 Granted 364,173 Vested (371,423) Forfeited (16,618) Balance at December 31, 2019 227,348 Granted 278,806 Vested (174,145) Forfeited — Balance at June 30, 2020 332,009
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 and six months ended June 30, 2020 and 2019. Three months ended June 30, Six months ended June 30, Vested LTIP units 2020 2019 2020 2019 Vested LTIP units 43,958 46,652 174,145 204,341 Fair value of vested LTIP units (in thousands) $ 1,213 $ 1,401 $ 5,074 $ 5,464

Equity Incentive Plan (Tables)

Equity Incentive Plan (Tables)	6 Months Ended
	Jun. 30, 2020
Share-based Payment Arrangement [Abstract]
Schedule of share-based payment award, performance unit awards, valuation assumptions	The following table summarizes the assumptions used in valuing the performance units granted during the six months ended June 30, 2020. Performance Units Assumptions Grant date January 8, 2020 Expected volatility 17.4 % Expected dividend yield 5.75 % Risk-free interest rate 1.59 % Fair value of performance units grant (in thousands) $ 5,389
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, and the Company’s director compensation for the three and six months ended June 30, 2020 and 2019. Three months ended June 30, Six months ended June 30, Non-Cash Compensation Expense (in thousands) 2020 2019 2020 2019 Restricted shares of common stock $ 481 $ 444 $ 948 $ 871 LTIP units 978 899 1,942 1,786 Performance units 1,341 1,096 2,648 1,955 Director compensation (1) 138 98 252 203 Total non-cash compensation expense $ 2,938 $ 2,537 $ 5,790 $ 4,815 (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 and six months ended June 30, 2020 and 2019. The number of shares of common stock granted is calculated based on the trailing ten days average common stock price ending on the third business day preceding the grant date.

Leases (Tables)

Leases (Tables)	6 Months Ended
	Jun. 30, 2020
Leases [Abstract]
Operating Lease, Lease Income [Table Text Block]	The following table summarizes the components of rental income recognized during the three and six months ended June 30, 2020 and 2019 included in the accompanying Consolidated Statements of Operations. Three months ended June 30, Six months ended June 30, Rental Income (in thousands) 2020 2019 2020 2019 Fixed lease payments $ 91,234 $ 74,958 $ 181,630 $ 147,075 Variable lease payments 25,588 19,258 50,594 41,439 Straight-line rental income 1,823 3,292 5,750 5,576 Net decrease to rental income related to above and below market lease amortization (1,174) (1,146) (2,164) (2,113) Total rental income $ 117,471 $ 96,362 $ 235,810 $ 191,977
Lessor, Operating Lease, Payments to be Received, Maturity	The following table summarizes the maturity of fixed lease payments under the Company’s leases as of June 30, 2020. Year Maturity of Fixed Lease Payments (in thousands) Remainder of 2020 $ 183,554 2021 $ 344,763 2022 $ 307,910 2023 $ 265,262 2024 $ 221,533 Thereafter $ 846,338
Lease, Cost [Table Text Block]	The following table summarizes supplemental information related to operating lease right-of-use assets and operating lease liabilities recognized in the Company’s Consolidated Balance Sheets as of June 30, 2020 and December 31, 2019. Operating Lease Term and Discount Rate June 30, 2020 December 31, 2019 Weighted average remaining lease term (years) 27.0 36.0 Weighted average discount rate 6.8 % 7.1 % The following table summarizes the operating lease cost recognized during the three and six months ended June 30, 2020 and 2019 included in the Company’s Consolidated Statements of Operations. Three months ended June 30, Six months ended June 30, Operating Lease Cost (in thousands) 2020 2019 2020 2019 Operating lease cost included in property expense attributable to ground leases $ 331 $ 331 $ 662 $ 662 Operating lease cost included in general and administrative expense attributable to corporate office lease 423 267 741 533 Total operating lease cost $ 754 $ 598 $ 1,403 $ 1,195 The following table summarizes supplemental cash flow information related to operating leases recognized during the six months ended June 30, 2020 and 2019 in the Company’s Consolidated Statements of Cash Flows. Six months ended June 30, Operating Leases (in thousands) 2020 2019 Cash paid for amounts included in the measurement of lease liabilities (operating cash flows) $ 1,143 $ 1,141 Right-of-use assets obtained in exchange for new lease liabilities $ 7,718 $ —
Lessee, Operating Lease, Liability, Maturity [Table Text Block]	The following table summarizes the maturity of operating lease liabilities under the Company’s ground leases and corporate office lease as of June 30, 2020. Year Maturity of Operating Lease Liabilities (1) (in thousands) Remainder of 2020 $ 1,150 2021 2,102 2022 2,975 2023 3,021 2024 3,064 Thereafter 50,017 Total lease payments 62,329 Less: Imputed interest (38,050) Present value of operating lease liabilities $ 24,279 (1) Operating lease liabilities do not include estimates of CPI rent changes required by certain ground lease agreements. Therefore, actual payments may differ than those presented.

Earnings Per Share (Tables)

Earnings Per Share (Tables)	6 Months Ended
	Jun. 30, 2020
Earnings Per Share [Abstract]
Schedule of computation of basic and diluted earnings per common share	The following table reconciles the numerators and denominators in the computation of basic and diluted earnings per common share for the three and six months ended June 30, 2020 and 2019. Three months ended June 30, Six months ended June 30, Earnings Per Share (in thousands, except per share data) 2020 2019 2020 2019 Numerator Net income attributable to common stockholders $ 17,552 $ 12,394 $ 79,635 $ 18,201 Denominator Weighted average common shares outstanding — basic 148,663 125,251 148,116 120,015 Effect of dilutive securities (1) Share-based compensation 364 309 225 291 Shares issuable under forward sales agreements — — — — Weighted average common shares outstanding — diluted 149,027 125,560 148,341 120,306 Net income per share — basic and diluted Net income per share attributable to common stockholders — basic $ 0.12 $ 0.10 $ 0.54 $ 0.15 Net income per share attributable to common stockholders — diluted $ 0.12 $ 0.10 $ 0.54 $ 0.15

Organization and Description _2

Organization and Description of Business (Details) ft² in Millions	3 Months Ended	6 Months Ended
	Mar. 31, 2020	Jun. 30, 2020ft²buildingstate
Real Estate Properties [Line Items]
Number of properties		457
Number of states in which the entity owned buildings | state		38
Area (in square feet) | ft²		91.8
STAG Industrial, Inc. [Member]
Real Estate Properties [Line Items]
Ownership interest in Operating Partnership (as a percent)	97.50%	97.70%
Warehouse - Distribution buildings
Real Estate Properties [Line Items]
Number of properties		379
Light Manufacturing buildings
Real Estate Properties [Line Items]
Number of properties		70
Flex/Office Buildings
Real Estate Properties [Line Items]
Number of properties		8

Organization, Consolidation and

Organization, Consolidation and Presentation of Financial Statements - COVID-19 Pandemic (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Rent Deferrals Granted	$ 1.5	$ 1.5

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Restricted Cash (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019	Jun. 30, 2019	Dec. 31, 2018
Accounting Policies [Abstract]
Cash and cash equivalents	$ 102,097	$ 9,041
Restricted cash	12,505	2,823
Cash and cash equivalents and restricted cash—end of period	$ 114,602	$ 11,864	$ 9,595	$ 22,542

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Taxes (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Business Acquisition [Line Items]
Net income	$ 19,316,000	$ 14,170,000	$ 84,354,000	$ 21,559,000
State and local income, excise and franchise taxes	500,000	400,000	900,000	600,000
Liabilities for uncertain tax positions	0		0		$ 0
Real Estate Investment Trust
Business Acquisition [Line Items]
Net income	$ 0	$ 300,000	$ 0	$ 300,000

Rental Property - Summary (Deta

Rental Property - Summary (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Property Subject to or Available for Operating Lease [Line Items]
Rental property, net	$ 4,038,197	$ 3,998,507
Deferred leasing intangible assets, accumulated amortization	267,553	241,304
Land
Property Subject to or Available for Operating Lease [Line Items]
Rental property, net	444,489	435,923
Buildings, net of accumulated depreciation of $292,467 and $254,458, respectively
Property Subject to or Available for Operating Lease [Line Items]
Rental property, net	2,833,458	2,787,234
Rental property, accumulated depreciation	292,467	254,458
Tenant improvements, net of accumulated depreciation of $23,724 and $21,487, respectively
Property Subject to or Available for Operating Lease [Line Items]
Rental property, net	38,638	38,339
Rental property, accumulated depreciation	23,724	21,487
Building and land improvements, net of accumulated depreciation of $130,170 and $111,688, respectively
Property Subject to or Available for Operating Lease [Line Items]
Rental property, net	239,214	232,456
Rental property, accumulated depreciation	130,170	111,688
Construction in progress
Property Subject to or Available for Operating Lease [Line Items]
Rental property, net	30,660	29,406
Deferred leasing intangibles, net of accumulated amortization of $267,553 and $241,304, respectively
Property Subject to or Available for Operating Lease [Line Items]
Rental property, net	$ 451,738	$ 475,149

Rental Property - Acquisitions

Rental Property - Acquisitions (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020USD ($)ft²building	Mar. 31, 2020USD ($)ft²building	Jun. 30, 2020USD ($)ft²building
Business Acquisition [Line Items]
Area (in square feet)	91,800,000		91,800,000
Acquisitions 2020
Business Acquisition [Line Items]
Area (in square feet)	1,721,669		1,721,669
Number of Buildings Acquired | building			11
Business Combination, Consideration Transferred | $			$ 131,257
Acquistions Q1 2020
Business Acquisition [Line Items]
Area (in square feet)		1,599,389
Number of Buildings Acquired | building		9
Business Combination, Consideration Transferred | $		$ 119,343
Canton, MI - 1-10-20
Business Acquisition [Line Items]
Area (in square feet)		491,049
Number of Buildings Acquired | building		1
Business Combination, Consideration Transferred | $		$ 29,543
Rochester, NY - 1-10-20
Business Acquisition [Line Items]
Area (in square feet)		124,850
Number of Buildings Acquired | building		1
Business Combination, Consideration Transferred | $		$ 8,565
Hudson, WI - 2-6-20
Business Acquisition [Line Items]
Area (in square feet)		139,875
Number of Buildings Acquired | building		1
Business Combination, Consideration Transferred | $		$ 10,460
McClellan, CA - 2-6-20
Business Acquisition [Line Items]
Area (in square feet)		160,534
Number of Buildings Acquired | building		1
Business Combination, Consideration Transferred | $		$ 18,468
Richmond, VA - 2-6-20
Business Acquisition [Line Items]
Area (in square feet)		78,128
Number of Buildings Acquired | building		1
Business Combination, Consideration Transferred | $		$ 5,481
Muskego, WI - 2-7-20
Business Acquisition [Line Items]
Area (in square feet)		81,230
Number of Buildings Acquired | building		1
Business Combination, Consideration Transferred | $		$ 7,219
Warren, MI - 2-11-20
Business Acquisition [Line Items]
Area (in square feet)		311,123
Number of Buildings Acquired | building		1
Business Combination, Consideration Transferred | $		$ 23,141
Langhorne, PA - 3-9-20
Business Acquisition [Line Items]
Area (in square feet)		78,000
Number of Buildings Acquired | building		1
Business Combination, Consideration Transferred | $		$ 6,571
Tulsa, OK - 3-9-20
Business Acquisition [Line Items]
Area (in square feet)		134,600
Number of Buildings Acquired | building		1
Business Combination, Consideration Transferred | $		$ 9,895
Acquisitions Q2 2020
Business Acquisition [Line Items]
Area (in square feet)	122,280		122,280
Number of Buildings Acquired | building	2
Business Combination, Consideration Transferred | $	$ 11,914
Rancho Cordova, CA 6-11-20
Business Acquisition [Line Items]
Area (in square feet)	54,463		54,463
Number of Buildings Acquired | building	1
Business Combination, Consideration Transferred | $	$ 5,730
Schaumburg, IL 6-29-20
Business Acquisition [Line Items]
Area (in square feet)	67,817		67,817
Number of Buildings Acquired | building	1
Business Combination, Consideration Transferred | $	$ 6,184

Rental Property - Acquisition_2

Rental Property - Acquisitions - Allocation of Consideration (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2020USD ($)
Allocation of the consideration paid for the acquired assets and liabilities
Land	$ 10,498
Buildings	92,860
Tenant improvements	1,535
Building and land improvements	4,670
Other assets	450
Total purchase price	131,257
Construction in progress
Allocation of the consideration paid for the acquired assets and liabilities
Construction in progress	669
In-place leases
Allocation of the consideration paid for the acquired assets and liabilities
Deferred leasing intangibles	$ (14,963)
Weighted average amortization period of lease intangibles	7 years 10 months 24 days
Tenant relationships
Allocation of the consideration paid for the acquired assets and liabilities
Deferred leasing intangibles	$ (7,115)
Weighted average amortization period of lease intangibles	11 years 1 month 6 days
Above market leases
Allocation of the consideration paid for the acquired assets and liabilities
Deferred leasing intangibles	$ (1,069)
Weighted average amortization period of lease intangibles	6 years 3 months 18 days
Below market leases
Allocation of the consideration paid for the acquired assets and liabilities
Deferred leasing intangibles	$ 2,572
Weighted average amortization period of lease intangibles	5 years 4 months 24 days

Rental Property - Acquisition_3

Rental Property - Acquisitions - Results of Operations (Details) - Acquisitions 2020 - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2020
Business Acquisition [Line Items]
Revenue	$ 2,807	$ 4,748
Net income (loss)	$ 609	$ 861

Rental Property - Disposals (De

Rental Property - Disposals (Details) ft² in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020USD ($)ft²building	Jun. 30, 2019USD ($)	Jun. 30, 2020USD ($)ft²building	Jun. 30, 2019USD ($)	Dec. 31, 2019USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of buildings disposed | building	457		457
Area (in square feet) | ft²	91.8		91.8
Carrying value of property sold	$ 4,038,197,000		$ 4,038,197,000		$ 3,998,507,000
Disposal Group, Disposed of by Sale, Not Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of buildings disposed | building	4		4
Area (in square feet) | ft²	1.2		1.2
Carrying value of property sold	$ 54,100,000		$ 54,100,000
Contribution to revenue	0	$ 1,100,000	0	$ 2,500,000
Disposal Group, Including Discontinued Operation, Operating Income (Loss)	$ (49,000)	$ (35,000)	(200,000)	$ 400,000
Net proceeds from sales of rental property			101,900,000
Gain (Loss) on Sale			$ 47,800,000

Rental Property - Loss on Impai

Rental Property - Loss on Impairments (Details) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2019USD ($)	Jun. 30, 2019USD ($)building
Real Estate [Abstract]
Impairment of Real Estate | $	$ 0	$ 5.3
Number of Buildings Impaired | building		1

Rental Property - Gain on Invol

Rental Property - Gain on Involuntary Conversion (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Gain on involuntary conversion	$ 657	$ 0	$ 657	$ 0
Other Operating Income (Expense) [Member]
Gain on involuntary conversion	$ 700		$ 700

Rental Property - Deferred Leas

Rental Property - Deferred Leasing Intangibles (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Deferred leasing intangibles, gross	$ 719,291		$ 719,291		$ 716,453
Deferred leasing intangibles assets, accumulated amortization	(267,553)		(267,553)		(241,304)
Deferred leasing intangibles, net	451,738		451,738		475,149
Below market lease, gross	39,409		39,409		38,802
Below market lease, accumulated amortization	(13,117)		(13,117)		(12,064)
Below market lease, net	26,292		26,292		26,738
Net decrease to rental income related to above and below market lease amortization	1,174	$ 1,146	2,164	$ 2,113
Above market leases
Finite-Lived Intangible Assets [Line Items]
Deferred leasing intangibles, gross	92,793		92,793		92,607
Deferred leasing intangibles assets, accumulated amortization	(36,413)		(36,413)		(32,115)
Deferred leasing intangibles, net	56,380		56,380		60,492
Other intangible lease assets
Finite-Lived Intangible Assets [Line Items]
Deferred leasing intangibles, gross	626,498		626,498		623,846
Deferred leasing intangibles assets, accumulated amortization	(231,140)		(231,140)		(209,189)
Deferred leasing intangibles, net	395,358		395,358		$ 414,657
Amortization expense related to other intangible lease assets	21,076	$ 17,899	41,378	$ 34,713
Estimated Net Amortization of In-Place Leases, Leasing Commissions and Tenant Relationships
Remainder of 2020	36,982		36,982
2021	65,116		65,116
2022	55,459		55,459
2023	46,930		46,930
2024	38,019		38,019
Net decrease to rental income related to above and below market lease amortization
Estimated Net Amortization of In-Place Leases, Leasing Commissions and Tenant Relationships
Remainder of 2020	1,827		1,827
2021	2,717		2,717
2022	2,190		2,190
2023	2,395		2,395
2024	$ 2,703		$ 2,703

Debt - Summary (Details)

Debt - Summary (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2020USD ($)extention	Mar. 19, 2021	Sep. 29, 2020	Jul. 15, 2020	Apr. 17, 2020USD ($)extention	Dec. 31, 2019USD ($)
Debt Instrument [Line Items]
Long-term debt, gross	$ 1,603,092					$ 1,651,085
Unamortized debt issuance costs	(6,935)					(6,111)
Unamortized fair market value premium	34					39
Principal outstanding	$ 1,596,191					1,645,013
Weighted average interest rate	3.48%
Interest Rate Swaps
Debt Instrument [Line Items]
Derivative notional amount swapped	$ 775,000
London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Stated interest rate	0.16225%
Term Loan | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.00%
$300 Million Unsecured Term Loan [Member]
Debt Instrument [Line Items]
Long-term debt, gross					$ 300,000
Number Of Extensions | extention					2
Debt Instrument Term Extension Period	1 year
$300 Million Unsecured Term Loan [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.50%
$300 Million Unsecured Term Loan [Member] | London Interbank Offered Rate (LIBOR) [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.25%
Unsecured Credit Facility
Debt Instrument [Line Items]
Principal outstanding	$ 0					146,000
Debt Instrument, Maturity Date	Jan. 12, 2024
Maximum borrowing capacity	$ 500,000
Number Of Extensions | extention	2
Debt Instrument Term Extension Period	6 months
Unsecured Credit Facility | Prepaid Expenses and Other Assets
Debt Instrument [Line Items]
Unamortized debt issuance costs	$ (2,000)					(2,400)
Unsecured Credit Facility | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.90%
Unsecured Term Loans
Debt Instrument [Line Items]
Long-term debt, gross	$ 975,000					875,000
Unamortized debt issuance costs	(4,718)					(3,625)
Principal outstanding	970,282					871,375
Unsecured Term Loans | $150 Million Wells Fargo Unsecured Term Loan C
Debt Instrument [Line Items]
Long-term debt, gross	$ 0					150,000
Debt Instrument, Interest Rate, Effective Percentage	2.39%
Debt Instrument, Maturity Date	Sep. 29, 2020
Unsecured Term Loans | $150 Million Wells Fargo Unsecured Term Loan B
Debt Instrument [Line Items]
Long-term debt, gross	$ 0					150,000
Debt Instrument, Interest Rate, Effective Percentage	3.05%
Debt Instrument, Maturity Date	Mar. 21, 2021
Unsecured Term Loans | $150 Million Wells Fargo Unsecured Term Loan A
Debt Instrument [Line Items]
Long-term debt, gross	$ 150,000					150,000
Debt Instrument, Interest Rate, Effective Percentage	3.38%
Debt Instrument, Maturity Date	Mar. 31, 2022
Fixed Interest Rate (as a percent)	2.38%
Unsecured Term Loans | $150 Million Unsecured Term Loan D [Member]
Debt Instrument [Line Items]
Long-term debt, gross	$ 150,000					150,000
Debt Instrument, Interest Rate, Effective Percentage	2.85%
Debt Instrument, Maturity Date	Jan. 4, 2023
Fixed Interest Rate (as a percent)	1.85%
Unsecured Term Loans | $300 Million Unsecured Term Loan [Member]
Debt Instrument [Line Items]
Long-term debt, gross	$ 300,000					0
Debt Instrument, Interest Rate, Effective Percentage	3.31%
Debt Instrument, Maturity Date	Apr. 18, 2023
Fixed Interest Rate (as a percent)	1.72%
Unsecured Term Loans | $300 Million Unsecured Term Loan [Member] | Scenario, Forecast [Member]
Debt Instrument [Line Items]
Fixed Interest Rate (as a percent)		0.28%	1.17%
Unsecured Term Loans | $175 Million Unsecured Term Loan E [Member]
Debt Instrument [Line Items]
Long-term debt, gross	$ 175,000					175,000
Debt Instrument, Interest Rate, Effective Percentage	3.92%
Debt Instrument, Maturity Date	Jan. 15, 2024
Fixed Interest Rate (as a percent)	2.92%
Unsecured Term Loans | $200 Million Unsecured Term Loan F [Member]
Debt Instrument [Line Items]
Long-term debt, gross	$ 200,000					100,000
Debt Instrument, Maturity Date	Jan. 12, 2025
Unsecured Term Loans | $200 Million Unsecured Term Loan F [Member] | Scenario, Forecast [Member]
Debt Instrument [Line Items]
Fixed Interest Rate (as a percent)				2.11%
Unsecured Term Loans | $200 Million Unsecured Term Loan F [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.00%
Unsecured Notes
Debt Instrument [Line Items]
Long-term debt, gross	$ 575,000					575,000
Unamortized debt issuance costs	(1,918)					(2,117)
Principal outstanding	573,082					572,883
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%
Debt Instrument, Maturity Date	Jan. 5, 2023
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%
Debt Instrument, Maturity Date	Oct. 1, 2024
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%
Debt Instrument, Maturity Date	Feb. 20, 2025
Unsecured Notes | $75 Million Series G Unsecured Notes [Member]
Debt Instrument [Line Items]
Long-term debt, gross	$ 75,000					75,000
Stated interest rate	4.10%
Debt Instrument, Maturity Date	Jun. 13, 2025
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%
Debt Instrument, Maturity Date	Jul. 1, 2026
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%
Debt Instrument, Maturity Date	Dec. 30, 2026
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%
Debt Instrument, Maturity Date	Feb. 20, 2027
Unsecured Notes | $100 Million Series H Unsecured Notes [Member]
Debt Instrument [Line Items]
Long-term debt, gross	$ 100,000					100,000
Stated interest rate	4.27%
Debt Instrument, Maturity Date	Jun. 13, 2028
Mortgage Loans Payable
Debt Instrument [Line Items]
Long-term debt, gross	$ 53,092					55,085
Unamortized debt issuance costs	(299)					(369)
Unamortized fair market value premium	34					39
Principal outstanding	52,827					54,755
Mortgage Loans Payable | Wells Fargo Bank, National Association CMBS Loan
Debt Instrument [Line Items]
Long-term debt, gross	$ 49,473					51,406
Stated interest rate	4.31%
Debt Instrument, Maturity Date	Dec. 1, 2022
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	$ 3,619					$ 3,679
Stated interest rate	4.78%
Debt Instrument, Maturity Date	Dec. 15, 2023
Penalty free prepayment period	3 months

Debt - 2020 Activity (Details)

Debt - 2020 Activity (Details)	Apr. 29, 2020USD ($)	Apr. 17, 2020USD ($)extention	Mar. 25, 2020USD ($)	Jun. 30, 2020USD ($)extention	Jun. 30, 2019USD ($)	Jun. 30, 2020USD ($)extention	Jun. 30, 2019USD ($)	Dec. 31, 2019USD ($)
Debt Instrument [Line Items]
Debt Instrument, Unused Borrowing Capacity, Amount				$ 497,000,000		$ 497,000,000
Line of Credit Facility, Accordion Feature, Increase Limit		$ 600,000,000
Debt Instrument, Covenant Compliance						The Company was in compliance with all financial and other covenants		The Company was in compliance with all financial and other covenants
Net book value of properties that are collateral for debt arrangements				$ 82,800,000		$ 82,800,000		$ 85,500,000
Unsecured Credit Facility
Debt Instrument [Line Items]
Number Of Extensions | extention				2		2
Debt Instrument Term Extension Period						6 months
Accounts Payable and Accrued Liabilities [Member]
Debt Instrument [Line Items]
Interest payable				$ 6,100,000	$ 6,300,000	$ 6,100,000	$ 6,300,000
Interest Expense [Member]
Debt Instrument [Line Items]
Amortization of deferred financing fees				746,000	618,000	1,422,000	1,236,000
Line of Credit Facility, Commitment Fee Amount				$ 316,000	$ 387,000	680,000	$ 770,000
Wells Fargo Bank, National Association CMBS Loan | Johnstown, NY, Q4 2012, One [Member]
Debt Instrument [Line Items]
Extinguishment of Debt, Amount	$ 1,000,000
Write off of Deferred Debt Issuance Cost						$ 100,000
$300 Million Unsecured Term Loan [Member]
Debt Instrument [Line Items]
Write off of Deferred Debt Issuance Cost		$ 700,000
Number Of Extensions | extention		2
Debt Instrument Term Extension Period						1 year
First Extention Fee		0.15%
Second Extention Fee		0.0020
Debt Issuance Costs, Gross		$ 2,100,000
Deferred Financing Accrued Extension Fee		1,100,000
Debt Instrument, Fee Amount		$ 35,000
$200 Million Unsecured Term Loan F [Member]
Debt Instrument [Line Items]
Proceeds from Issuance of Debt			$ 100,000,000

Debt - Fair Value (Details)

Debt - Fair Value (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Long-term debt, gross	$ 1,603,092	$ 1,651,085
Unamortized fair market value premium	34	39
Unamortized debt issuance costs	(6,935)	(6,111)
Principal outstanding	1,596,191	1,645,013
Long-term debt, fair value	1,636,797	1,691,514
Unsecured Credit Facility
Debt Instrument [Line Items]
Principal outstanding	0	146,000
Long-term debt, fair value	0	146,000
Unsecured Term Loans
Debt Instrument [Line Items]
Long-term debt, gross	975,000	875,000
Unamortized debt issuance costs	(4,718)	(3,625)
Principal outstanding	970,282	871,375
Long-term debt, fair value	964,497	875,000
Unsecured Notes
Debt Instrument [Line Items]
Long-term debt, gross	575,000	575,000
Unamortized debt issuance costs	(1,918)	(2,117)
Principal outstanding	573,082	572,883
Long-term debt, fair value	617,073	614,493
Mortgage Loans Payable
Debt Instrument [Line Items]
Long-term debt, gross	53,092	55,085
Unamortized fair market value premium	34	39
Unamortized debt issuance costs	(299)	(369)
Principal outstanding	52,827	54,755
Long-term debt, fair value	$ 55,227	$ 56,021

Derivative Financial Instrume_3

Derivative Financial Instruments - Risk Management and Unsecured Loan Swaps (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Interest Rate Swaps
Unsecured Term Loan Swaps
Notional amount assets	$ 0	$ 250,000
Notional amount liabilities	1,275,000	850,000
Notional amount liabilities	1,275,000	$ 850,000
Interest Rate Derivative, The Toronto-Dominion Bank, September 29, 2016
Unsecured Term Loan Swaps
Notional amount liabilities	25,000
Derivative Liability, Fair Value, Gross Liability	$ (76)
Fixed Interest Rate (as a percent)	1.383%
Notional amount liabilities	$ 25,000
Derivative Liability, Fair Value, Gross Liability	$ (76)
Fixed Interest Rate (as a percent)	1.383%
Interest Rate Derivative, PNC Bank, September 29, 2016
Unsecured Term Loan Swaps
Notional amount liabilities	$ 50,000
Derivative Liability, Fair Value, Gross Liability	$ (153)
Fixed Interest Rate (as a percent)	1.3906%
Notional amount liabilities	$ 50,000
Derivative Liability, Fair Value, Gross Liability	$ (153)
Fixed Interest Rate (as a percent)	1.3906%
Interest Rate Derivative, Regions Bank, September 29, 2016
Unsecured Term Loan Swaps
Notional amount liabilities	$ 35,000
Derivative Liability, Fair Value, Gross Liability	$ (106)
Fixed Interest Rate (as a percent)	1.3858%
Notional amount liabilities	$ 35,000
Derivative Liability, Fair Value, Gross Liability	$ (106)
Fixed Interest Rate (as a percent)	1.3858%
Interest Rate Derivative, US Bank, September 29, 2016
Unsecured Term Loan Swaps
Notional amount liabilities	$ 25,000
Derivative Liability, Fair Value, Gross Liability	$ (77)
Fixed Interest Rate (as a percent)	1.395%
Notional amount liabilities	$ 25,000
Derivative Liability, Fair Value, Gross Liability	$ (77)
Fixed Interest Rate (as a percent)	1.395%
Interest Rate Derivative, Capital One, September 29, 2016
Unsecured Term Loan Swaps
Notional amount liabilities	$ 15,000
Derivative Liability, Fair Value, Gross Liability	$ (46)
Fixed Interest Rate (as a percent)	1.395%
Notional amount liabilities	$ 15,000
Derivative Liability, Fair Value, Gross Liability	$ (46)
Fixed Interest Rate (as a percent)	1.395%
Interest Rate Derivative, Royal Bank of Canada, March 20, 2015
Unsecured Term Loan Swaps
Notional amount liabilities	$ 25,000
Derivative Liability, Fair Value, Gross Liability	$ (280)
Fixed Interest Rate (as a percent)	1.709%
Notional amount liabilities	$ 25,000
Derivative Liability, Fair Value, Gross Liability	$ (280)
Fixed Interest Rate (as a percent)	1.709%
Interest Rate Derivative, The Toronto-Dominion Bank, March 20, 2015
Unsecured Term Loan Swaps
Notional amount liabilities	$ 25,000
Derivative Liability, Fair Value, Gross Liability	$ (280)
Fixed Interest Rate (as a percent)	1.7105%
Notional amount liabilities	$ 25,000
Derivative Liability, Fair Value, Gross Liability	$ (280)
Fixed Interest Rate (as a percent)	1.7105%
Interest Rate Derivative, The Toronto-Dominion Bank, September 10, 2017
Unsecured Term Loan Swaps
Notional amount liabilities	$ 100,000
Derivative Liability, Fair Value, Gross Liability	$ (1,493)
Fixed Interest Rate (as a percent)	2.2255%
Notional amount liabilities	$ 100,000
Derivative Liability, Fair Value, Gross Liability	$ (1,493)
Fixed Interest Rate (as a percent)	2.2255%
Interest Rate Derivative, Wells Fargo Bank, March 20, 2015
Unsecured Term Loan Swaps
Notional amount liabilities	$ 25,000
Derivative Liability, Fair Value, Gross Liability	$ (750)
Fixed Interest Rate (as a percent)	1.828%
Notional amount liabilities	$ 25,000
Derivative Liability, Fair Value, Gross Liability	$ (750)
Fixed Interest Rate (as a percent)	1.828%
Interest Rate Derivative, The Toronto-Dominion Bank, February 14, 2020
Unsecured Term Loan Swaps
Notional amount liabilities	$ 25,000
Derivative Liability, Fair Value, Gross Liability	$ (1,027)
Fixed Interest Rate (as a percent)	2.4535%
Notional amount liabilities	$ 25,000
Derivative Liability, Fair Value, Gross Liability	$ (1,027)
Fixed Interest Rate (as a percent)	2.4535%
Interest Rate Derivative, Regions Bank, February 14, 2020
Unsecured Term Loan Swaps
Notional amount liabilities	$ 50,000
Derivative Liability, Fair Value, Gross Liability	$ (2,072)
Fixed Interest Rate (as a percent)	2.475%
Notional amount liabilities	$ 50,000
Derivative Liability, Fair Value, Gross Liability	$ (2,072)
Fixed Interest Rate (as a percent)	2.475%
Interest Rate Derivative, Capital One, February 14, 2020
Unsecured Term Loan Swaps
Notional amount liabilities	$ 50,000
Derivative Liability, Fair Value, Gross Liability	$ (2,121)
Fixed Interest Rate (as a percent)	2.53%
Notional amount liabilities	$ 50,000
Derivative Liability, Fair Value, Gross Liability	$ (2,121)
Fixed Interest Rate (as a percent)	2.53%
Interest Rate Derivative, The Toronto-Dominion Bank, October 30, 2017
Unsecured Term Loan Swaps
Notional amount liabilities	$ 25,000
Derivative Liability, Fair Value, Gross Liability	$ (1,093)
Fixed Interest Rate (as a percent)	1.8485%
Notional amount liabilities	$ 25,000
Derivative Liability, Fair Value, Gross Liability	$ (1,093)
Fixed Interest Rate (as a percent)	1.8485%
Interest Rate Derivative, Royal Bank of Canada, October 30, 2017
Unsecured Term Loan Swaps
Notional amount liabilities	$ 25,000
Derivative Liability, Fair Value, Gross Liability	$ (1,094)
Fixed Interest Rate (as a percent)	1.8505%
Notional amount liabilities	$ 25,000
Derivative Liability, Fair Value, Gross Liability	$ (1,094)
Fixed Interest Rate (as a percent)	1.8505%
Interest Rate Derivative, Wells Fargo Bank, October 30, 2017
Unsecured Term Loan Swaps
Notional amount liabilities	$ 25,000
Derivative Liability, Fair Value, Gross Liability	$ (1,094)
Fixed Interest Rate (as a percent)	1.8505%
Notional amount liabilities	$ 25,000
Derivative Liability, Fair Value, Gross Liability	$ (1,094)
Fixed Interest Rate (as a percent)	1.8505%
Interest Rate Derivative, PNC Bank, $25m, October 30, 2017
Unsecured Term Loan Swaps
Notional amount liabilities	$ 25,000
Derivative Liability, Fair Value, Gross Liability	$ (1,093)
Fixed Interest Rate (as a percent)	1.8485%
Notional amount liabilities	$ 25,000
Derivative Liability, Fair Value, Gross Liability	$ (1,093)
Fixed Interest Rate (as a percent)	1.8485%
Interest Rate Derivative, PNC Bank, $50m, October 30, 2017
Unsecured Term Loan Swaps
Notional amount liabilities	$ 50,000
Derivative Liability, Fair Value, Gross Liability	$ (2,184)
Fixed Interest Rate (as a percent)	1.8475%
Notional amount liabilities	$ 50,000
Derivative Liability, Fair Value, Gross Liability	$ (2,184)
Fixed Interest Rate (as a percent)	1.8475%
Interest Rate Derivative, TD Bank, $75m, Sep 29, 2020
Unsecured Term Loan Swaps
Notional amount liabilities	$ 75,000
Derivative Liability, Fair Value, Gross Liability	$ (290)
Fixed Interest Rate (as a percent)	0.275%
Notional amount liabilities	$ 75,000
Derivative Liability, Fair Value, Gross Liability	$ (290)
Fixed Interest Rate (as a percent)	0.275%
Interest Rate Derivative, Wells Fargo Bank, $75m, Sep 29, 2020
Unsecured Term Loan Swaps
Notional amount liabilities	$ 75,000
Derivative Liability, Fair Value, Gross Liability	$ (298)
Fixed Interest Rate (as a percent)	0.279%
Notional amount liabilities	$ 75,000
Derivative Liability, Fair Value, Gross Liability	$ (298)
Fixed Interest Rate (as a percent)	0.279%
Interest Rate Derivative, TD Bank, $75m, March 19, 2021
Unsecured Term Loan Swaps
Notional amount liabilities	$ 75,000
Derivative Liability, Fair Value, Gross Liability	$ (251)
Fixed Interest Rate (as a percent)	0.275%
Notional amount liabilities	$ 75,000
Derivative Liability, Fair Value, Gross Liability	$ (251)
Fixed Interest Rate (as a percent)	0.275%
Interest Rate Derivative, Wells Fargo Bank, $75m, March 19, 2021
Unsecured Term Loan Swaps
Notional amount liabilities	$ 75,000
Derivative Liability, Fair Value, Gross Liability	$ (258)
Fixed Interest Rate (as a percent)	0.28%
Notional amount liabilities	$ 75,000
Derivative Liability, Fair Value, Gross Liability	$ (258)
Fixed Interest Rate (as a percent)	0.28%
Interest Rate Derivative, The Toronto-Dominion Bank, July 26, 2019 [Member]
Unsecured Term Loan Swaps
Notional amount liabilities	$ 50,000
Derivative Liability, Fair Value, Gross Liability	$ (4,932)
Fixed Interest Rate (as a percent)	2.918%
Notional amount liabilities	$ 50,000
Derivative Liability, Fair Value, Gross Liability	$ (4,932)
Fixed Interest Rate (as a percent)	2.918%
Interest Rate Derivative, PNC Bank, July 26, 2019 [Member]
Unsecured Term Loan Swaps
Notional amount liabilities	$ 50,000
Derivative Liability, Fair Value, Gross Liability	$ (4,932)
Fixed Interest Rate (as a percent)	2.919%
Notional amount liabilities	$ 50,000
Derivative Liability, Fair Value, Gross Liability	$ (4,932)
Fixed Interest Rate (as a percent)	2.919%
Interest Rate Derivative, Bank of Montreal, July 26, 2019 [Member]
Unsecured Term Loan Swaps
Notional amount liabilities	$ 50,000
Derivative Liability, Fair Value, Gross Liability	$ (4,932)
Fixed Interest Rate (as a percent)	2.919%
Notional amount liabilities	$ 50,000
Derivative Liability, Fair Value, Gross Liability	$ (4,932)
Fixed Interest Rate (as a percent)	2.919%
Interest Rate Derivative, US Bank, July 26, 2019 [Member]
Unsecured Term Loan Swaps
Notional amount liabilities	$ 25,000
Derivative Liability, Fair Value, Gross Liability	$ (2,466)
Fixed Interest Rate (as a percent)	2.919%
Notional amount liabilities	$ 25,000
Derivative Liability, Fair Value, Gross Liability	$ (2,466)
Fixed Interest Rate (as a percent)	2.919%
Interest Rate Derivative, Wells Fargo Bank, July 15, 2020 [Member]
Unsecured Term Loan Swaps
Notional amount liabilities	$ 50,000
Derivative Liability, Fair Value, Gross Liability	$ (4,633)
Fixed Interest Rate (as a percent)	2.246%
Notional amount liabilities	$ 50,000
Derivative Liability, Fair Value, Gross Liability	$ (4,633)
Fixed Interest Rate (as a percent)	2.246%
Interest Rate Derivative, US Bank, July 15, 2020 [Member]
Unsecured Term Loan Swaps
Notional amount liabilities	$ 50,000
Derivative Liability, Fair Value, Gross Liability	$ (4,632)
Fixed Interest Rate (as a percent)	2.2459%
Notional amount liabilities	$ 50,000
Derivative Liability, Fair Value, Gross Liability	$ (4,632)
Fixed Interest Rate (as a percent)	2.2459%
Interest Rate Derivative, Regions Bank, July 15, 2020 [Member]
Unsecured Term Loan Swaps
Notional amount liabilities	$ 50,000
Derivative Liability, Fair Value, Gross Liability	$ (4,632)
Fixed Interest Rate (as a percent)	2.2459%
Notional amount liabilities	$ 50,000
Derivative Liability, Fair Value, Gross Liability	$ (4,632)
Fixed Interest Rate (as a percent)	2.2459%
Interest Rate Derivative, Bank of Montreal, July 15, 2020
Unsecured Term Loan Swaps
Notional amount liabilities	$ 50,000
Derivative Liability, Fair Value, Gross Liability	$ (3,436)
Fixed Interest Rate (as a percent)	1.7165%
Notional amount liabilities	$ 50,000
Derivative Liability, Fair Value, Gross Liability	$ (3,436)
Fixed Interest Rate (as a percent)	1.7165%

Derivative Financial Instrume_4

Derivative Financial Instruments - FV of Interest Rate Swaps (Details) - Interest Rate Swaps - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Fair value of the interest rate swaps outstanding
Notional amount assets	$ 0	$ 250,000
Fair value - assets	0	303
Notional amount liabilities	1,275,000	850,000
Fair Value - liabilities	$ (50,731)	$ (18,819)

Derivative Financial Instrume_5

Derivative Financial Instruments - Cash Flow Hedges and Contingent Features (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
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	$ 15,333,000	$ 12,193,000	$ 30,197,000	$ 25,027,000
Interest Rate Swaps
Cash Flow Hedges of Interest Rate Risk
Additional amount reclassified from accumulated other comprehensive income (loss) as a increase (decrease) to interest expense over the next twelve months	17,500,000		17,500,000
Loss recognized in accumulated other comprehensive loss on interest rate swaps	5,249,000	14,946,000	36,336,000	20,802,000
Income (loss) reclassified from accumulated other comprehensive loss into income as interest expense	(3,240,000)	1,082,000	(4,136,000)	2,204,000
Total interest expense presented in the Consolidated Statements of Operations in which the effects of cash flow hedges are recorded	15,333,000	$ 12,193,000	30,197,000	$ 25,027,000
Assets Needed for Immediate Settlement, Aggregate Fair Value	$ 51,600,000		$ 51,600,000

Derivative Financial Instrume_6

Derivative Financial Instruments - FV on Recurring Basis (Details) - Interest Rate Swaps - Fair value on recurring basis - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Assets (liabilities):
Interest rate swaps-Asset	$ 0	$ 303
Interest rate swaps-Liability	(50,731)	(18,819)
Level 1
Assets (liabilities):
Interest rate swaps-Asset	0	0
Interest rate swaps-Liability	0	0
Level 2
Assets (liabilities):
Interest rate swaps-Asset	0	303
Interest rate swaps-Liability	(50,731)	(18,819)
Level 3
Assets (liabilities):
Interest rate swaps-Asset	0	0
Interest rate swaps-Liability	$ 0	$ 0

Equity - Preferred Stock (Detai

Equity - Preferred Stock (Details) - $ / shares	Jul. 09, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Dec. 31, 2019
Class of Stock [Line Items]
Preferred Stock, Shares Authorized		20,000,000		20,000,000				20,000,000	20,000,000
Series C Preferred Stock
Class of Stock [Line Items]
Preferred Stock, Shares Issued		3,000,000		3,000,000				3,000,000	3,000,000
Preferred Stock, Liquidation Preference Per Share		$ 25		$ 25				$ 25	$ 25
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	$ 0.8593750	$ 1.7187500
Dividends Payable, Date Declared		Apr. 9, 2020	Jan. 8, 2020	Oct. 15, 2019	Jul. 15, 2019	Apr. 9, 2019	Jan. 10, 2019
Dividends Payable, Date to be Paid		Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jul. 1, 2019	Apr. 1, 2019
Subsequent Event [Member] | Series C Preferred Stock
Class of Stock [Line Items]
Preferred Stock, Dividends Per Share, Declared	$ 0.4296875

Equity - Common Stock ATM (Deta

Equity - Common Stock ATM (Details) - USD ($) $ / shares in Units, $ in Thousands	Jan. 16, 2020	Jan. 13, 2020	Dec. 31, 2019	Jun. 30, 2020
Class of Stock [Line Items]
Common Stock, Shares Authorized			300,000,000	300,000,000
Net proceeds from the sale of common stock	$ 173,100
Sale of Stock, Number of Shares Issued in Transaction		10,062,500
Shares Issued, Price Per Share		$ 30.9022
Warrant [Member]
Class of Stock [Line Items]
Sale of Stock, Number of Shares Issued in Transaction		4,462,500
Common Stock
Class of Stock [Line Items]
Sale of Stock, Number of Shares Issued in Transaction		5,600,000
At The Market Program 2019 $600 Million
Class of Stock [Line Items]
Common Stock Value Authorized under Stock Offering Program				$ 600,000
At The Market Program 2019 $600 Million | Common Stock
Class of Stock [Line Items]
Aggregate value of common stock available to be sold under the ATM				$ 318,248
Number of shares sold			9,711,706
Net proceeds from the sale of common stock			$ 279,156
Over-Allotment Option
Class of Stock [Line Items]
Sale of Stock, Number of Shares Issued in Transaction		1,312,500
Weighted Average | At The Market Program 2019 $600 Million | Common Stock
Class of Stock [Line Items]
Sale of Stock, Price Per Share			$ 29.01

Equity - Common Stock Dividends

Equity - Common Stock Dividends (Details) - $ / shares

Jul. 09, 2020

Jun. 30, 2020

May 31, 2020

Apr. 30, 2020

Mar. 31, 2020

Feb. 29, 2020

Jan. 31, 2020

Dec. 31, 2019

Nov. 30, 2019

Oct. 31, 2019

Sep. 30, 2019

Aug. 31, 2019

Jul. 31, 2019

Jun. 30, 2019

May 31, 2019

Apr. 30, 2019

Mar. 31, 2019

Feb. 28, 2019

Jan. 31, 2019

Mar. 31, 2020

Jun. 30, 2020

Class of Stock [Line Items]

Common Stock, Shares Authorized

300,000,000

300,000,000

300,000,000

Common Stock, Dividends, Per Share, Cash Paid

$ 0.119167

$ 0.119167

$ 0.119167

$ 0.119167

$ 0.119167

$ 0.119167

$ 0.119167

$ 0.119167

$ 0.119167

$ 0.119167

$ 0.119167

$ 0.119167

$ 1.430004

Common Stock, Dividends, Per Share, Declared

$ 0.12

$ 0.12

$ 0.12

$ 0.12

$ 0.12

$ 0.12

$ 0.119167

$ 0.119167

$ 0.119167

$ 0.119167

$ 0.119167

$ 0.119167

$ 0.119167

$ 0.119167

$ 0.119167

$ 0.119167

$ 0.119167

$ 0.119167

$ 1.430004

$ 0.72

Subsequent Event [Member]

Class of Stock [Line Items]

Common Stock, Dividends, Per Share, Declared

$ 0.12

Common Stock

Class of Stock [Line Items]

Dividends Payable, Date Declared

Apr. 9, 2020

Apr. 9, 2020

Apr. 9, 2020

Jan. 8, 2020

Jan. 8, 2020

Jan. 8, 2020

Oct. 15, 2019

Oct. 15, 2019

Oct. 15, 2019

Jul. 15, 2019

Jul. 15, 2019

Jul. 15, 2019

Apr. 9, 2019

Apr. 9, 2019

Apr. 9, 2019

Jan. 10, 2019

Jan. 10, 2019

Jan. 10, 2019

Dividends Payable, Date to be Paid

Jul. 15, 2020

Jun. 15, 2020

May 15, 2020

Apr. 15, 2020

Mar. 16, 2020

Feb. 18, 2020

Jan. 15, 2020

Dec. 16, 2019

Nov. 15, 2019

Oct. 15, 2019

Sep. 16, 2019

Aug. 15, 2019

Jul. 15, 2019

Jun. 17, 2019

May 15, 2019

Apr. 15, 2019

Mar. 15, 2019

Feb. 15, 2019

Equity - Restricted Stock (Deta

Equity - Restricted Stock (Details) - Restricted stock - USD ($) $ / shares in Units, $ in Thousands	Feb. 13, 2020	Jan. 08, 2020	Jan. 07, 2019	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Jan. 01, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)	4 years	4 years
Shares
Unvested at beginning of period (in shares)					193,045		193,045	190,462
Granted (in shares)					110,830		75,419
Vested (in shares)				0	(101,109)	0	(78,010)	(78,431)
Forfeited (in shares)					(7,138)		(858)
Unvested at end of period (in shares)				189,596			189,596
Fair value of restricted stock per share at grant date	$ 32.64	$ 31.49	$ 24.85				$ 31.60
Stock Repurchased and Retired During Period, Shares					28,504		33,119
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value				$ 27.77			$ 27.77		$ 24.38
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value							23.11
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value							$ 24.85
Unrecognized compensation costs				$ 4,200			$ 4,200
Unrecognized compensation costs, period for recognition							2 years 8 months 12 days
Vested (in shares)				0	(101,109)	0	(78,010)	(78,431)
Fair value of shares vested				$ 0		$ 0	$ 2,463	$ 1,951

Noncontrolling Interest - Summa

Noncontrolling Interest - Summary (Details) - $ / shares	Jan. 08, 2020	Mar. 31, 2020	Jun. 30, 2020	Jun. 30, 2019	Jan. 01, 2020	Dec. 31, 2019	Dec. 31, 2018
Limited Partner
Noncontrolling interest
Noncontrolling interest ownership percentage			2.30%			2.50%	3.50%
LTIP Units
Noncontrolling interest
stag_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingWeightedAverageGrantDateFairValue			$ 23.19		$ 21.64
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	$ 29.47		29.47
stag_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsConvertedWeightedAverageGrantDateFairValue			$ 18.72
Noncontrolling Interest - Unit holders in Operating Partnership
Noncontrolling interest
Units outstanding, balance at beginning of period (in units)		3,736,852	3,736,852	4,069,434
Granted/Issued		364,173	278,806
Forfeited		16,618	0
Conversions from LTIP units to Other Common Units		0	0
Redemptions from Other Common Units to common stock		680,137	447,730
Units outstanding, balance at end of period (in units)			3,567,928
LTIP Units | Noncontrolling Interest - Unit holders in Operating Partnership
Noncontrolling interest
Units outstanding, balance at beginning of period (in units)		1,697,358	1,697,358	1,616,200
Granted/Issued		364,173	278,806
Forfeited		16,618	0
Conversions from LTIP units to Other Common Units		266,397	197,775
Redemptions from Other Common Units to common stock		0	0
Units outstanding, balance at end of period (in units)			1,778,389
Other Common Units | Noncontrolling Interest - Unit holders in Operating Partnership
Noncontrolling interest
Units outstanding, balance at beginning of period (in units)		2,039,494	2,039,494	2,453,234
Granted/Issued		0	0
Forfeited		0	0
Conversions from LTIP units to Other Common Units		266,397	197,775
Redemptions from Other Common Units to common stock		680,137	447,730
Units outstanding, balance at end of period (in units)			1,789,539

Noncontrolling Interest - LTIP

Noncontrolling Interest - LTIP FV Assumptions (Details) - LTIP Units - USD ($)	Jan. 08, 2020	Mar. 31, 2020	Jun. 30, 2020
Assumptions
Expected term (years)	10 years
Expected volatility	18.00%
Expected dividend yield	5.75%
Risk-free interest rate	1.61%
Fair value of LTIP units at issuance (in thousands)	$ 4,030,000
Granted (in shares)	136,741	364,173	278,806
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	$ 29.47		$ 29.47
Share-based Compensation Award, Tranche One [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)	4 years
Independent Director | Share-based Compensation Award, Tranche One [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)	1 year

Noncontrolling Interest - LTI_2

Noncontrolling Interest - LTIP Units (Details) - LTIP Units - USD ($) $ / shares in Units, $ in Thousands	Jan. 08, 2020	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Jan. 01, 2020
Units
Unvested at beginning of period (in shares)			227,348		227,348	251,216
Granted	136,741		364,173		278,806
Vested (in units)		(43,958)	(371,423)	(46,652)	(174,145)	(204,341)
Forfeited (in units)			(16,618)		0
Unvested at end of period (in shares)		332,009			332,009
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value		$ 26.92			$ 26.92		$ 23.37
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	$ 29.47				29.47
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value					$ 26.38
Unrecognized compensation costs		$ 6,500			$ 6,500
Unrecognized compensation costs, period for recognition					2 years 6 months
Vested (in units)		43,958	371,423	46,652	174,145	204,341
Fair value of units vested		$ 1,213		$ 1,401	$ 5,074	$ 5,464

Equity Incentive Plan - Perform

Equity Incentive Plan - Performance Plan Assumptions (Details) - Performance shares $ in Thousands	Jan. 08, 2020USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility	17.40%
Expected dividend yield	5.75%
Risk-free interest rate	1.59%
Fair value of performance units grant (in thousands)	$ 5,389

Equity Incentive Plan - 2020 Ac

Equity Incentive Plan - 2020 Activity (Details) - USD ($) $ in Millions	Feb. 13, 2020	Jan. 08, 2020	Jan. 07, 2019	Mar. 31, 2020	Jun. 30, 2020
LTIP Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted		136,741		364,173	278,806
Unrecognized compensation costs					$ 6.5
Unrecognized compensation costs, period for recognition					2 years 6 months
Restricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)	4 years	4 years
Stock Repurchased and Retired During Period, Shares				28,504	33,119
Granted				110,830	75,419
Unrecognized compensation costs					$ 4.2
Unrecognized compensation costs, period for recognition					2 years 8 months 12 days
Performance shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation costs					$ 8.6
Unrecognized compensation costs, period for recognition					2 years
Performance Units Granted in 2017 [Domain] | LTIP Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)			1 year
Issuance of vested LTIP units and shares		76,096
Stock Repurchased and Retired During Period, Shares		18,241
Granted		65,969
Performance Units Granted in 2017 [Domain] | Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Issuance of vested LTIP units and shares		46,376
Performance Units Granted in 2017 [Domain] | Restricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)			1 year
Granted		3,398

Equity Incentive Plan - Equity

Equity Incentive Plan - Equity Non-cash Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
General and Administrative Expenses
Equity Incentive Plan
Share-based compensation	$ 2,938	$ 2,537	$ 5,790	$ 4,815
Restricted stock | General and Administrative Expenses
Equity Incentive Plan
Share-based compensation	481	444	948	871
LTIP Units | General and Administrative Expenses
Equity Incentive Plan
Share-based compensation	978	899	1,942	1,786
Performance shares | General and Administrative Expenses
Equity Incentive Plan
Share-based compensation	1,341	1,096	2,648	1,955
Independent Director | General and Administrative Expenses
Equity Incentive Plan
Share-based compensation	$ 138	$ 98	$ 252	$ 203
Common Stock | Independent Director
Equity Incentive Plan
Number of days of average trailing stock price used to calculate number of shares of common stock granted			10 days	10 days

Leases - Rental Income (Details

Leases - Rental Income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Leases [Abstract]
Fixed lease payments	$ 91,234	$ 74,958	$ 181,630	$ 147,075
Variable lease payments	25,588	19,258	50,594	41,439
Straight-line rental income	1,823	3,292	5,750	5,576
Net decrease to rental income related to above and below market lease amortization	(1,174)	(1,146)	(2,164)	(2,113)
Rental income	$ 117,471	$ 96,362	$ 235,810	$ 191,977

Leases - Tenant Accounts Receiv

Leases - Tenant Accounts Receivable (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2020USD ($)	Jun. 30, 2019USD ($)	Jun. 30, 2020USD ($)leases	Jun. 30, 2019USD ($)	Dec. 31, 2019USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Cash Basis Leases | leases			6
Accrued Rent Adjustment To Rental Income Resulting From Lease Collectibility Assessment	$ 1,200,000	$ 0	$ 900,000	$ 0
Contractual Rent Adjustment To Rental Income Resulting From Lease Collectibility Assessment	600,000	0	600,000	0
Lease Security Deposits Available in Letters of Credit	28,200,000		28,200,000		$ 22,600,000
Lease security deposits in restricted cash	700,000		700,000		700,000
Lease security deposits included in tenant prepaid rent and security deposits on the Balance Sheet	10,000,000		10,000,000		9,800,000
Real Estate Taxes, Tenant Responsibility	4,900,000	$ 4,100,000	9,700,000	$ 8,000,000
Accrued Income Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Deferred Rent Receivables, Net	$ 51,300,000		$ 51,300,000		$ 44,300,000

Leases - Maturity of Fixed Leas

Leases - Maturity of Fixed Lease Payments (Details) $ in Thousands	Jun. 30, 2020USD ($)
Leases [Abstract]
2020	$ 183,554
2021	344,763
2022	307,910
2023	265,262
2024	221,533
Thereafter	$ 846,338

Leases - Lessee Leases (Details

Leases - Lessee Leases (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Lessee, Lease, Description [Line Items]
Operating Lease, Weighted Average Remaining Lease Term	27 years		27 years		36 years
Operating Lease, Weighted Average Discount Rate, Percent	6.80%		6.80%		7.10%
Lease, Cost	$ 754	$ 598	$ 1,403	$ 1,195
Operating Lease, Payments			1,143	1,141
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability			$ 7,718	0
Minimum [Member]
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Term of Contract	6 years		6 years
Lessee, Operating Lease, Renewal Term	10 years		10 years
Maximum [Member]
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Term of Contract	46 years 6 months		46 years 6 months
Lessee, Operating Lease, Renewal Term	20 years		20 years
Operating Expense [Member]
Lessee, Lease, Description [Line Items]
Lease, Cost	$ 331	331	$ 662	662
General and Administrative Expenses
Lessee, Lease, Description [Line Items]
Lease, Cost	$ 423	$ 267	$ 741	$ 533

Leases - Maturity of Operating

Leases - Maturity of Operating Lease Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Leases [Abstract]
2020	$ 1,150
2021	2,102
2022	2,975
2023	3,021
2024	3,064
Thereafter	50,017
Lessee, Operating Lease, Liability, Payments, Due	62,329
Less: Imputed interest	(38,050)
Operating lease liabilities	$ 24,279	$ 16,989

Earnings Per Share (Details)

Earnings Per Share (Details) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Earnings Per Share [Abstract]
Participating securities	189,895	220,482	185,821	217,187

Earnings Per Share - Reconcilia

Earnings Per Share - Reconciliation of Numerator and Denominator (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Numerator
Net income attributable to common stockholders	$ 17,552	$ 12,394	$ 79,635	$ 18,201
Denominator
Weighted average common shares outstanding — basic	148,663	125,251	148,116	120,015
Shares issuable under forward sales agreements	0	0	0	0
Weighted average common shares outstanding — diluted	149,027	125,560	148,341	120,306
Net income per share — basic and diluted
Net income per share attributable to common stockholders — basic	$ 0.12	$ 0.10	$ 0.54	$ 0.15
Net income per share attributable to common stockholders — diluted	$ 0.12	$ 0.10	$ 0.54	$ 0.15
Restricted stock
Net income per share — basic and diluted
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	190	220	186	217
Stock Compensation Plan
Denominator
Share-based compensation	364	309	225	291

Commitments and Contingencies -

Commitments and Contingencies - Agreements (Details) $ in Millions	Jun. 30, 2020USD ($)
Commitments and Contingencies Disclosure [Abstract]
Letters of credit outstanding	$ 3