Office Properties Income Trust (OPI) 10-K15 Feb 232022 FY Annual reportFinancial data

Company Profile

Cover Page

Cover Page - USD ($) $ in Millions	12 Months Ended
Cover Page - USD ($) $ in Millions	Dec. 31, 2022	Feb. 14, 2023	Jun. 30, 2022
Document Information [Line Items]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2022
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	1-34364
Entity Registrant Name	OFFICE PROPERTIES INCOME TRUST
Entity Incorporation, State or Country Code	MD
Entity Tax Identification Number	26-4273474
Entity Address, Address Line One	Two Newton Place
Entity Address, Address Line Two	255 Washington Street
Entity Address, Address Line Three	Suite 300
Entity Address, City or Town	Newton
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02458-1634
City Area Code	617
Local Phone Number	219-1440
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
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
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 948.4
Entity Common Stock, Shares Outstanding		48,564,103
Documents Incorporated by Reference	Certain information required by Items 10, 11, 12, 13 and 14 of Part III of this Annual Report on Form 10-K is incorporated by reference to our definitive Proxy Statement for the 2023 Annual Meeting of Shareholders, to be filed with the Securities and Exchange Commission within 120 days after the fiscal year ended December 31, 2022.
Entity Central Index Key	0001456772
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	FY
Amendment Flag	false
Common Shares
Document Information [Line Items]
Title of 12(b) Security	Common Shares of Beneficial Interest
Trading Symbol	OPI
Security Exchange Name	NASDAQ
6.375% Senior Notes Due 2050
Document Information [Line Items]
Title of 12(b) Security	6.375% Senior Notes due 2050
Trading Symbol	OPINL
Security Exchange Name	NASDAQ

Audit Information

Audit Information	12 Months Ended
Audit Information	Dec. 31, 2022
Auditor Information [Abstract]
Auditor Name	Deloitte & Touche LLP
Auditor Location	Boston, Massachusetts
Auditor Firm ID	34

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Real estate properties:
Land	$ 821,238	$ 874,108
Buildings and improvements	3,114,836	3,036,978
Total real estate properties, gross	3,936,074	3,911,086
Accumulated depreciation	(561,458)	(495,912)
Total real estate properties, net	3,374,616	3,415,174
Assets of properties held for sale	2,516	26,598
Investments in unconsolidated joint ventures	35,129	34,838
Acquired real estate leases, net	369,333	505,629
Cash and cash equivalents	12,249	83,026
Restricted cash	0	1,489
Rents receivable	105,639	112,886
Deferred leasing costs, net	73,098	53,883
Other assets, net	7,397	8,160
Total assets	3,979,977	4,241,683
LIABILITIES AND SHAREHOLDERS’ EQUITY
Unsecured revolving credit facility	195,000	0
Senior unsecured notes, net	2,187,875	2,479,772
Mortgage notes payable, net	49,917	98,178
Liabilities of properties held for sale	73	594
Accounts payable and other liabilities	140,151	142,609
Due to related persons	6,469	6,787
Assumed real estate lease obligations, net	14,157	17,034
Total liabilities	2,593,642	2,744,974
Commitments and contingencies
Shareholders’ equity:
Common shares of beneficial interest, $.01 par value: 200,000,000 shares authorized, 48,565,644 and 48,425,665 shares issued and outstanding, respectively	486	484
Additional paid in capital	2,619,532	2,617,169
Cumulative net income	169,606	175,715
Cumulative common distributions	(1,403,289)	(1,296,659)
Total shareholders’ equity	1,386,335	1,496,709
Total liabilities and shareholders’ equity	$ 3,979,977	$ 4,241,683

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Dec. 31, 2022	Dec. 31, 2021
Statement of Financial Position [Abstract]
Common shares of beneficial interest, par value (in dollars per share)	$ 0.01	$ 0.01
Common shares of beneficial interest, shares authorized (in shares)	200,000,000	200,000,000
Common shares of beneficial interest, shares issued (in shares)	48,565,644	48,425,665
Common shares of beneficial interest, shares outstanding (in shares)	48,565,644	48,425,665

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Income Statement [Abstract]
Rental income	$ 554,275	$ 576,482	$ 587,919
Expenses:
Real estate taxes	57,844	71,970	65,119
Utility expenses	27,005	25,251	25,384
Other operating expenses	110,366	105,825	105,465
Depreciation and amortization	222,564	241,494	251,566
Loss on impairment of real estate	21,820	62,420	2,954
Acquisition and transaction related costs	292	0	232
General and administrative	25,134	26,858	28,443
Total expenses	465,025	533,818	479,163
Gain on sale of real estate	11,001	78,354	10,855
Interest and other income	217	7	779
Interest expense (including net amortization of debt premiums, discounts and issuance costs of $9,134, $9,771 and $9,593, respectively)	(103,480)	(112,385)	(108,303)
Gain (loss) on early extinguishment of debt	682	(14,068)	(3,839)
Income (loss) before income tax expense and equity in net losses of investees	(2,330)	(5,428)	8,248
Income tax expense	(270)	(251)	(377)
Equity in net losses of investees	(3,509)	(2,501)	(1,193)
Net income (loss)	(6,109)	(8,180)	6,678
Other comprehensive income:
Unrealized gain on financial instrument	0	0	200
Other comprehensive income	0	0	200
Comprehensive income (loss)	$ (6,109)	$ (8,180)	$ 6,878
Weighted average common shares outstanding, basic (in shares)	48,278	48,195	48,124
Weighted average common shares outstanding, diluted (in shares)	48,278	48,195	48,124
Per common share amounts (basic and diluted):
Net income (loss) - basic (in dollars per share)	$ (0.14)	$ (0.17)	$ 0.14
Net income (loss) - diluted (in dollars per share)	$ (0.14)	$ (0.17)	$ 0.14

CONSOLIDATED STATEMENTS OF CO_2

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Income Statement [Abstract]
Net amortization of debt premiums, discounts and issuance costs	$ 9,134	$ 9,771	$ 9,593

CONSOLIDATED STATEMENTS OF SHAR

CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Shares	Additional Paid In Capital	Cumulative Net Income	Cumulative Other Comprehensive Income (Loss)	Cumulative Common Distributions
Balance beginning (in shares) at Dec. 31, 2019		48,201,941
Balance beginning at Dec. 31, 2019	$ 1,705,754	$ 482	$ 2,612,425	$ 177,217	$ (200)	$ (1,084,170)
Increase (Decrease) in Shareholders' Equity
Share grants (in shares)		136,600
Share grants	3,324	$ 1	3,323
Shares forfeitures or repurchases (in shares)		(20,175)
Share forfeitures and repurchases	(443)		(443)
Amounts reclassified from cumulative other comprehensive income to net income	85				85
Unrealized gain on financial instruments	115				115
Net income (loss)	6,678			6,678
Distributions to common shareholders	(106,121)					(106,121)
Balance ending (in shares) at Dec. 31, 2020		48,318,366
Balance ending at Dec. 31, 2020	1,609,392	$ 483	2,615,305	183,895	0	(1,190,291)
Increase (Decrease) in Shareholders' Equity
Share grants (in shares)		145,800
Share grants	2,873	$ 1	2,872
Shares forfeitures or repurchases (in shares)		(38,501)
Share forfeitures and repurchases	(1,008)		(1,008)
Net income (loss)	(8,180)			(8,180)
Distributions to common shareholders	(106,368)					(106,368)
Balance ending (in shares) at Dec. 31, 2021		48,425,665
Balance ending at Dec. 31, 2021	1,496,709	$ 484	2,617,169	175,715	0	(1,296,659)
Increase (Decrease) in Shareholders' Equity
Share grants (in shares)		172,700
Share grants	2,916	$ 2	2,914
Shares forfeitures or repurchases (in shares)		(32,721)
Share forfeitures and repurchases	(551)		(551)
Net income (loss)	(6,109)			(6,109)
Distributions to common shareholders	(106,630)					(106,630)
Balance ending (in shares) at Dec. 31, 2022		48,565,644
Balance ending at Dec. 31, 2022	$ 1,386,335	$ 486	$ 2,619,532	$ 169,606	$ 0	$ (1,403,289)

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income (loss)	$ (6,109)	$ (8,180)	$ 6,678
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation	96,966	92,266	83,828
Net amortization of debt premiums, discounts and issuance costs	9,134	9,771	9,593
Amortization of acquired real estate leases and assumed real estate lease obligations, net	119,703	144,826	167,192
Amortization of deferred leasing costs	7,994	7,878	6,887
Gain on sale of real estate	(11,001)	(78,354)	(10,855)
Loss on impairment of real estate	21,820	62,420	2,954
(Gain) loss on early extinguishment of debt	(682)	9,694	2,701
Straight line rental income	(10,830)	(15,368)	(16,079)
Other non-cash expenses, net	1,818	1,782	2,229
Equity in net losses of investees	3,509	2,501	1,193
Change in assets and liabilities:
Rents receivable	10,961	2,663	(3,962)
Deferred leasing costs	(31,621)	(19,769)	(12,128)
Other assets	484	1,538	2,505
Accounts payable and other liabilities	(19,214)	7,151	(8,081)
Due to related persons	(318)	673	(1,027)
Net cash provided by operating activities	192,614	221,492	233,628
CASH FLOWS FROM INVESTING ACTIVITIES:
Real estate acquisitions	0	(563,447)	(47,215)
Real estate improvements	(204,104)	(100,141)	(81,762)
Proceeds from sale of properties, net	203,280	219,980	102,211
Contributions to unconsolidated joint ventures	(3,851)	0	0
Proceeds from repayment of mortgage note receivable	0	0	2,880
Net cash used in investing activities	(4,624)	(442,985)	(22,987)
CASH FLOWS FROM FINANCING ACTIVITIES:
Repayment of mortgage notes payable	(47,617)	(72,541)	(155,367)
Repayment of senior unsecured notes	(300,000)	(610,000)	(400,000)
Proceeds from issuance of senior unsecured notes, net	0	1,041,809	408,932
Borrowings on unsecured revolving credit facility	385,000	755,000	561,467
Repayments on unsecured revolving credit facility	(190,000)	(755,000)	(561,467)
Payment of debt issuance costs	(469)	(2,744)	(1,492)
Repurchase of common shares	(540)	(1,003)	(434)
Distributions to common shareholders	(106,630)	(106,368)	(106,121)
Net cash (used in) provided by financing activities	(260,256)	249,153	(254,482)
(Decrease) increase in cash, cash equivalents and restricted cash	(72,266)	27,660	(43,841)
Cash, cash equivalents and restricted cash at beginning of period	84,515	56,855	100,696
Cash, cash equivalents and restricted cash at end of period	12,249	84,515	56,855
SUPPLEMENTAL CASH FLOW INFORMATION:
Interest paid	104,174	103,200	100,083
Income taxes paid	352	299	1,377
NON-CASH INVESTING ACTIVITIES:
Real estate improvements accrued, not paid	42,772	18,492	11,981
Real estate acquisition	0	(13,031)	0
Capitalized interest	4,578	795	199
SUPPLEMENTAL DISCLOSURE OF CASH, CASH EQUIVALENTS AND RESTRICTED CASH:
Cash and cash equivalents	12,249	83,026	42,045
Restricted cash	0	1,489	14,810
Total cash, cash equivalents and restricted cash shown in the consolidated statements of cash flows	12,249	84,515	56,855
Unconsolidated Joint Ventures
CASH FLOWS FROM INVESTING ACTIVITIES:
Distributions in excess of earnings	51	612	612
Affiliates Insurance Company
CASH FLOWS FROM INVESTING ACTIVITIES:
Distributions in excess of earnings	$ 0	$ 11	$ 287

Organization

Organization	12 Months Ended
Organization	Dec. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization	OrganizationOffice Properties Income Trust, or OPI, we, us or our, is a real estate investment trust, or REIT, formed in 2009 under Maryland law.As of December 31, 2022, our wholly owned properties were comprised of 160 properties containing approximately 20,969,000 rentable square feet and we had noncontrolling ownership interests of 51% and 50% in two unconsolidated joint ventures that own three properties totaling approximately 444,000 rentable square feet.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
Summary of Significant Accounting Policies	Dec. 31, 2022
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Basis of Presentation. These consolidated financial statements include the accounts of us and our subsidiaries, all of which are wholly owned directly or indirectly by us. All intercompany transactions and balances with or among our consolidated subsidiaries have been eliminated. Real Estate Properties. We record our properties at cost and provide depreciation on real estate investments on a straight line basis over estimated useful lives generally ranging from 7 to 40 years. In some circumstances, we engage independent real estate appraisal firms to provide market information and evaluations which are relevant to our purchase price allocations and determinations of useful lives; however, we are ultimately responsible for the purchase price allocations and determinations of useful lives. We allocate the purchase prices of our properties to land, buildings and improvements based on determinations of the relative fair values of these assets assuming the properties are vacant. We determine the fair value of each property using methods similar to those used by independent appraisers, which may involve estimated cash flows that are based on a number of factors, including capitalization rates and discount rates, among others. We allocate a portion of the purchase price of our properties to above market and below market leases based on the present value (using an interest rate which reflects the risks associated with acquired in place leases at the time each property was acquired by us) of the difference, if any, between (i) the contractual amounts to be paid pursuant to the acquired in place leases and (ii) our estimates of fair market lease rates for the corresponding leases, measured over a period equal to the terms of the respective leases. We allocate a portion of the purchase price to acquired in place leases and tenant relationships based upon market estimates to lease up the property based on the leases in place at the time of purchase. We allocate this aggregate value between acquired in place lease values and tenant relationships based on our evaluation of the specific characteristics of each tenant’s lease. However, we have not separated the value of tenant relationships from the value of acquired in place leases because such value and related amortization expense is immaterial to the accompanying consolidated financial statements. In making these allocations, we consider factors such as estimated carrying costs during the expected lease up periods, including real estate taxes, insurance and other operating income and expenses and costs, such as leasing commissions, legal and other related expenses, to execute similar leases in current market conditions at the time a property was acquired by us. If the value of tenant relationships becomes material in the future, we may separately allocate those amounts and amortize the allocated amounts over the estimated life of the relationships. For transactions that qualify as business combinations, we allocate the excess, if any, of the consideration over the fair value of the assets acquired to goodwill. We amortize capitalized above market lease values (included in acquired real estate leases, net in our consolidated balance sheets) and below market lease values (presented as assumed real estate lease obligations, net in our consolidated balance sheets) as a reduction or increase, respectively, to rental income over the terms of the associated leases. Such amortization resulted in net decreases to rental income of $975, $2,288 and $5,440 during the years ended December 31, 2022, 2021 and 2020, respectively. We amortize the value of acquired in place leases (included in acquired real estate leases, net in our consolidated balance sheets), exclusive of the value of above market and below market acquired in place leases, over the terms of the associated leases. Such amortization, which is included in depreciation and amortization expense, amounted to $118,728, $142,538 and $161,752 during the years ended December 31, 2022, 2021 and 2020, respectively. If a lease is terminated prior to its stated expiration, we write off the unamortized amounts relating to that lease. As of December 31, 2022 and 2021, our acquired real estate leases and assumed real estate lease obligations, excluding properties classified as held for sale, were as follows: December 31, 2022 2021 Acquired real estate leases: Capitalized above market lease values $ 15,792 $ 29,925 Less: accumulated amortization (9,672) (17,945) Capitalized above market lease values, net 6,120 11,980 Lease origination value 728,773 885,250 Less: accumulated amortization (365,560) (391,601) Lease origination value, net 363,213 493,649 Acquired real estate leases, net $ 369,333 $ 505,629 Assumed real estate lease obligations: Capitalized below market lease values $ 27,033 $ 29,488 Less: accumulated amortization (12,876) (12,454) Assumed real estate lease obligations, net $ 14,157 $ 17,034 As of December 31, 2022, the weighted average amortization periods for capitalized above market leases, lease origination value and capitalized below market lease values were 3.8 years, 6.4 years and 10.9 years, respectively. Future amortization of net intangible lease assets and liabilities, to be recognized over the current terms of the associated leases as of December 31, 2022 are estimated to be $90,999 in 2023, $73,905 in 2024, $53,792 in 2025, $39,983 in 2026, $31,313 in 2027 and $65,184 thereafter. We regularly evaluate whether events or changes in circumstances have occurred that could indicate an impairment in the value of long lived assets. Impairment indicators may include declining tenant occupancy, lack of progress releasing vacant space, tenant bankruptcies, low long term prospects for improvement in property performance, weak or declining tenant profitability, cash flow or liquidity, our decision to dispose of an asset before the end of its estimated useful life and legislative, market or industry changes that could permanently reduce the value of a property. If there is an indication that the carrying value of an asset is not recoverable, we estimate the projected undiscounted cash flows to determine if an impairment loss should be recognized. The future net undiscounted cash flows are subjective and are based in part on assumptions regarding hold periods, market rents and terminal capitalization rates. We determine the amount of any impairment loss by comparing the historical carrying value to estimated fair value. We estimate fair value through an evaluation of recent financial performance and projected discounted cash flows using standard industry valuation techniques. In addition to consideration of impairment upon the events or changes in circumstances described above, we regularly evaluate the remaining useful lives of our long lived assets. If we change our estimate of the remaining useful lives, we allocate the carrying value of the affected assets over their revised remaining useful lives. Cash and Cash Equivalents. We consider highly liquid investments with original maturities of three months or less at the date of purchase to be cash equivalents. Restricted Cash. Restricted cash consists of amounts escrowed for future real estate taxes, insurance, leasing costs, capital expenditures and debt service, as required by certain of our mortgage debts. Deferred Leasing Costs . Deferred leasing costs include brokerage costs and inducements associated with our entering leases. We amortize deferred leasing costs, which are included in depreciation and amortization expense, and inducements, which are included as a reduction to rental income, on a straight line basis over the terms of the respective leases. Legal costs associated with the execution of our leases are expensed as incurred and included in general and administrative expenses in our consolidated statements of comprehensive income (loss). We recorded amortization of deferred leasing costs of $6,869, $6,691 and $5,985, and reductions to rental income related to the amortization of inducements of $1,124, $1,187 and $902 for the years ended December 31, 2022, 2021 and 2020, respectively. Deferred leasing costs, excluding properties classified as held for sale, totaled $94,680 and $74,469 at December 31, 2022 and 2021, respectively, and accumulated amortization of deferred leasing costs totaled $21,582 and $20,586 at December 31, 2022 and 2021, respectively. Future amortization of deferred leasing costs to be recognized during the current terms of our existing leases as of December 31, 2022 are estimated to be $9,938 in 2023, $8,837 in 2024, $7,838 in 2025, $7,260 in 2026, $6,424 in 2027 and $32,801 thereafter. Debt Issuance Costs . Costs related to the issuance or assumption of debt are capitalized and amortized to interest expense over the terms of the respective loans. Debt issuance costs, net of accumulated amortization, for our revolving credit facility are included in other assets in our consolidated balance sheets. As of December 31, 2022 and 2021, debt issuance costs for our revolving credit facility were $4,593 and $4,125, respectively, and accumulated amortization of debt issuance costs for our revolving credit facility were $4,072 and $3,079, respectively. Debt issuance costs, net of accumulated amortization, for our senior unsecured notes and mortgage notes payable are presented as a direct deduction from the associated debt liability in our consolidated balance sheets. As of December 31, 2022 and 2021, debt issuance costs, net of accumulated amortization, for our senior unsecured notes and mortgage notes payable totaled $13,589 and $16,120, respectively. Future amortization of debt issuance costs to be recognized with respect to our revolving credit facility and senior unsecured notes as of December 31, 2022 are estimated to be $2,676 in 2023, $2,155 in 2024, $1,669 in 2025, $1,335 in 2026, $595 in 2027 and $5,680 thereafter. Equity Method Investments. We have noncontrolling ownership interests of 51% and 50% in two unconsolidated joint ventures that own three properties. The properties owned by these joint ventures are encumbered by an aggregate of $82,000 of mortgage indebtedness. We do not control the activities that are most significant to these joint ventures and, as a result, we account for our investments in these joint ventures under the equity method of accounting. See Note 4 for more information regarding our unconsolidated joint ventures. We periodically evaluate our equity method investments for possible indicators of other than temporary impairment whenever events or changes in circumstances indicate the carrying amount of the investment might not be recoverable. These indicators may include the length of time and the extent to which the market value of our investment is below our carrying value, the financial condition of our investees, our intent and ability to be a long term holder of the investment and other considerations. If the decline in fair value is judged to be other than temporary, we record an impairment charge to adjust the basis of the investment to its estimated fair value. Other Liabilities. We initially acquired 1,541,201 shares of class A common stock of The RMR Group Inc., or RMR Inc., on June 5, 2015 for cash and share consideration of $17,462. We concluded, for accounting purposes, that the cash and share consideration we paid for our investment in these shares represented a discount to the fair value of these shares. We initially accounted for this investment under the cost method of accounting and recorded this investment at its estimated fair value of $39,833 as of June 5, 2015 using Level 3 inputs, as defined in the fair value hierarchy under U.S. generally accepted accounting principles, or GAAP. As a result, we recorded a liability for the amount by which the estimated fair value of these shares exceeded the price we paid for these shares. This liability is included in accounts payable and other liabilities in our consolidated balance sheets. This liability is being amortized on a straight line basis through December 31, 2035 as an allocated reduction to our business management and property management fee expense. We amortized $1,087 of this liability during each of the years ended December 31, 2022, 2021 and 2020. These amounts are included in the net business management and property management fee amounts for such periods disclosed in Note 6. As of December 31, 2022, the remaining unamortized amount of this liability was $14,145. Future amortization of this liability as of December 31, 2022 is estimated to be $1,087 in 2023 through 2027 and $8,710 thereafter. Revenue Recognition. We are a lessor of commercial office properties. Our leases provide our tenants with the contractual right to use and economically benefit from all of the physical space specified in the leases; therefore, we have determined to evaluate our leases as lease arrangements. Our leases provide for base rent payments and in addition may include variable payments. Rental income from operating leases, including any payments derived by index or market-based indices, is recognized on a straight line basis over the lease term when we have determined that the collectability of substantially all of the lease payments is probable. Some of our leases have options to extend or terminate the lease exercisable at the option of our tenants, which are considered when determining the lease term. Allowances for bad debts are recognized as a direct reduction of rental income. Certain of our leases contain non-lease components, such as property level operating expenses and capital expenditures reimbursed by our tenants as well as other required lease payments. We have made the policy election to not separate the lease and non-lease components because (i) the lease components are operating leases and (ii) the timing and pattern of recognition of the non-lease components are the same as those of the lease components. We apply Accounting Standards Codification 842, Leases , to the combined component. Income derived by our leases is recorded in rental income in our consolidated statements of comprehensive income (loss). Certain tenants are obligated to pay directly their obligations under their leases for insurance, real estate taxes and certain other expenses. These obligations, which have been assumed by the tenants under the terms of their respective leases, are not reflected in our consolidated financial statements. To the extent any tenant responsible for any such obligations under the applicable lease defaults on such lease or if it is deemed probable that the tenant will fail to pay for such obligations, we would record a liability for such obligations. See Note 5 for more information regarding our leases. Income Taxes. We have elected to be taxed as a REIT under the United States Internal Revenue Code of 1986, as amended, and, accordingly, we generally will not be subject to federal income taxes provided we distribute our taxable income and meet certain other requirements to qualify for taxation as a REIT. We are, however, subject to certain state and local taxes. Cumulative Other Comprehensive Income (Loss). Cumulative other comprehensive income (loss) represents our share of the cumulative comprehensive income and losses of our former equity method investees. Per Common Share Amounts. We calculate basic earnings per common share using the two class method. We calculate diluted earnings per share using the more dilutive of the two class method or the treasury stock method. Unvested share awards and other potentially dilutive common shares, together with the related impact on earnings, are considered when calculating diluted earnings per share. Use of Estimates. Preparation of these financial statements in conformity with GAAP requires us to make estimates and assumptions that may affect the amounts reported in these consolidated financial statements and related notes. The actual results could differ from these estimates. Significant estimates in the consolidated financial statements include purchase price allocations, useful lives of fixed assets and assessment of impairment of real estate and the related intangibles. Segment Reporting. We operate in one business segment: direct ownership of real estate properties.

Per Common Share Amounts

Per Common Share Amounts	12 Months Ended
Per Common Share Amounts	Dec. 31, 2022
Earnings Per Share [Abstract]
Per Common Share Amounts	Per Common Share Amounts The calculation of basic and diluted earnings per share is as follows (amounts in thousands, except per share amounts): Year Ended December 31, 2022 2021 2020 Numerators: Net income (loss) $ (6,109) $ (8,180) $ 6,678 Income attributable to unvested participating securities (427) — — Net income (loss) used in calculating earnings per share $ (6,536) $ (8,180) $ 6,678 Denominators: Weighted average common shares outstanding - basic and diluted (1) 48,278 48,195 48,124 Net income (loss) per common share - basic and diluted $ (0.14) $ (0.17) $ 0.14 (1) For the years ended December 31, 2022, 2021 and 2020, there were no dilutive common shares. In addition, for the years ended December 31, 2021 and 2020, 34 and 14 unvested common shares, respectively, were not included in the calculation of diluted earnings per share because to do so would have been antidilutive.

Real Estate Properties

Real Estate Properties	12 Months Ended
Real Estate Properties	Dec. 31, 2022
Real Estate [Abstract]
Real Estate Properties	Real Estate PropertiesAs of December 31, 2022, our wholly owned properties were comprised of 160 properties containing approximately 20,969,000 rentable square feet, with an undepreciated carrying value of $3,938,658, including $2,584 classified as held for sale. We also had noncontrolling ownership interests of 51% and 50% in two unconsolidated joint ventures that own three properties containing approximately 444,000 rentable square feet. We generally lease space at our properties on a gross lease, modified gross lease or net lease basis pursuant to fixed term contracts expiring between 2023 and 2053. Some of our leases generally require us to pay all or some property operating expenses and to provide all or most property management services. During the year ended December 31, 2022, we entered into 75 leases for approximately 2,562,000 rentable square feet for a weighted (by rentable square feet) average lease term of 9.3 years and we made commitments for $173,419 of leasing related costs. As of December 31, 2022, we had estimated unspent leasing related obligations of $156,693. Acquisition Activities 2022 Acquisition Activities We did not acquire any properties during the year ended December 31, 2022. 2021 Acquisition Activities During the year ended December 31, 2021, we acquired three properties containing approximately 926,000 rentable square feet for an aggregate purchase price of $576,478, including net purchase price adjustments of $1,761 and acquisition related costs of $1,264. These acquisitions were accounted for as asset acquisitions. We allocated the purchase prices of these acquisitions based on the relative estimated fair values of the acquired assets and assumed liabilities as follows: Acquisition Date Location Number of Properties Rentable Square Feet Purchase Price Land Buildings and Improvements Acquired Real Estate Leases Assumed Real Estate Lease Obligations June 2021 Chicago, IL (1) 1 531,000 $ 368,331 $ 42,935 $ 258,348 $ 76,136 $ (9,088) June 2021 Atlanta, GA 1 346,000 180,602 13,040 135,459 32,103 — August 2021 Boston, MA 1 49,000 27,545 16,103 10,217 1,225 — 3 926,000 $ 576,478 $ 72,078 $ 404,024 $ 109,464 $ (9,088) (1) Purchase price includes an adjustment of $13,031 t o record an estimated real estate tax liability as of the acquisition date. 2020 Acquisition Activities During the year ended December 31, 2020, we acquired two properties containing approximately 163,000 rentable square feet for an aggregate purchase price of $47,215, including capitalized acquisition related costs of $590. These acquisitions were accounted for as asset acquisitions. We allocated the purchase prices of these acquisitions based on the relative estimated fair values of the acquired assets as follows: Acquisition Date Location Number of Properties Rentable Square Feet Purchase Price Land Buildings and Improvements Acquired Real Estate Leases February 2020 Boston, MA 1 13,000 $ 11,864 $ 2,618 $ 9,246 $ — December 2020 Fort Mill, SC 1 150,000 35,351 5,031 22,526 7,794 2 163,000 $ 47,215 $ 7,649 $ 31,772 $ 7,794 Disposition Activities The sales completed during the years ended December 31, 2022, 2021 and 2020, as presented in the tables below, do not represent significant dispositions individually or in the aggregate, nor do they represent a strategic shift in our business. As a result, the results of operations of these properties are included in continuing operations through the date of sale in our consolidated statements of comprehensive income (loss). 2022 Disposition Activities During the year ended December 31, 2022, we sold 18 properties containing approximately 2,326,000 rentable square feet for an aggregate sales price of $211,020, excluding closing costs. Date of Sale Number of Properties Location Rentable Square Feet Gross Sales Price (1) Gain (Loss) on Sale of Real Estate Loss on Impairment of Real Estate January 2022 1 Rockville, MD (2) 129,000 $ 6,750 $ (72) $ — February 2022 2 Chesapeake, VA (2) 172,000 18,945 2,296 — March 2022 1 Milwaukee, WI (2) 29,000 3,775 (75) — May 2022 1 Holtsville, NY 264,000 28,500 1,900 — June 2022 1 Fairfax, VA 184,000 19,750 (13,537) — July 2022 1 Houston, TX 206,000 9,800 (135) 15,278 August 2022 3 Birmingham, AL 448,000 16,050 (265) 3,709 August 2022 1 Erlanger, KY 86,000 2,600 135 2,184 September 2022 2 Chesapeake, VA 214,000 24,000 62 649 September 2022 2 Everett, WA 112,000 31,500 11,959 — September 2022 1 Salem, OR 233,000 34,250 5,369 — November 2022 1 Kapolei, HI (3) 109,000 4,000 2,504 — November 2022 1 Englewood, CO 140,000 11,100 860 — 18 2,326,000 $ 211,020 $ 11,001 $ 21,820 (1) Gross sales price is the gross contract price, excluding closing costs. (2) Properties were classified as held for sale as of December 31, 2021. (3) Property is a leasable land parcel. As of December 31, 2022, we had three properties located in Richmond, VA containing approximately 89,000 rentable square feet classified as held for sale in our consolidated balance sheets. These properties were sold in January 2023 for a sales price of $5,350, excluding closing costs. As of February 14, 2023, we have entered into agreements to sell two properties containing approximately 207,000 rentable square feet for an aggregate sales price of $7,600, excluding closing costs. These pending sales are subject to conditions, accordingly, we cannot be sure that we will complete these sales or that these sales will not be delayed or the terms will not change. 2021 Disposition Activities During the year ended December 31, 2021, we sold six properties, a warehouse facility and two vacant land parcels containing approximately 2,565,000 rentable square feet for an aggregate sales price of $226,915, excluding closing costs. Date of Sale Number of Properties Location Rentable Square Feet Gross Sales Price (1) Gain (Loss) on Sale of Real Estate Loss on Impairment of Real Estate January 2021 — Kansas City, MO (2) (3) 10,000 $ 845 $ (63) $ — January 2021 1 Richmond, VA (2) 311,000 130,000 54,181 — April 2021 1 Huntsville, AL 1,371,000 39,000 — 5,383 July 2021 1 Fresno, CA 532,000 6,000 — 33,902 July 2021 1 Liverpool, NY 38,000 650 31 — August 2021 1 Memphis, TN 205,000 15,270 287 — September 2021 1 Stoneham, MA 98,000 6,650 (282) 5,911 October 2021 — Sterling, VA (4) — 28,500 24,200 — 6 2,565,000 $ 226,915 $ 78,354 $ 45,196 (1) Gross sales price is the gross contract price, excluding closing costs. (2) Properties were classified as held for sale as of December 31, 2020. (3) Consists of a warehouse facility. (4) Consists of two vacant land parcels. We also recorded a $10,658 loss on impairment of real estate to reduce the carrying value of three properties that were classified as held for sale to their estimated fair values less costs to sell as of September 30, 2021. Subsequently, we removed these properties from held for sale status due to a change of plan for sale and recorded an impairment adjustment of $425 to increase the carrying value of these properties to their estimated fair value as of December 31, 2021. In addition, we recorded a $6,991 loss on impairment of real estate to reduce the carrying value of two properties that were classified as held for sale as of December 31, 2021 and subsequently sold in 2022. 2020 Disposition Activities During the year ended December 31, 2020, we sold 10 properties containing approximately 906,000 rentable square feet for an aggregate sales price of $110,463, excluding closing costs and including the repayment of one mortgage note with an outstanding principal balance of $13,095, an annual interest rate of 5.9% and a maturity date in August 2021. Date of Sale Number of Properties Location Rentable Square Feet Gross Sales Price (1) Gain (Loss) on Sale of Real Estate Loss on Impairment of Real Estate January 2020 2 Stafford, VA 65,000 $ 14,063 $ 4,771 $ — January 2020 1 Windsor, CT 97,000 7,000 314 — February 2020 1 Lincolnshire, IL 223,000 12,000 1,179 — March 2020 1 Trenton, NJ 267,000 30,100 (179) — March 2020 1 Fairfax, VA 83,000 22,200 4,754 — October 2020 4 Fairfax, VA 171,000 25,100 16 2,954 10 906,000 $ 110,463 $ 10,855 $ 2,954 (1) Gross sales price is the gross contract price, excluding closing costs. Unconsolidated Joint Ventures We own interests in two joint ventures that own three properties. We account for these investments under the equity method of accounting. As of December 31, 2022 and 2021, our investments in unconsolidated joint ventures consisted of the following: OPI Ownership OPI Carrying Value of Investments at December 31, Number of Properties Location Rentable Square Feet Joint Venture 2022 2021 Prosperity Metro Plaza 51% $ 19,237 $ 20,672 2 Fairfax, VA 329,000 1750 H Street, NW 50% 15,892 14,166 1 Washington, D.C. 115,000 Total $ 35,129 $ 34,838 3 444,000 The following table provides a summary of the mortgage debt of our two unconsolidated joint ventures: Joint Venture Interest Rate (1) Maturity Date Principal Balance at December 31, 2022 and 2021 (2) Prosperity Metro Plaza 4.09% 12/1/2029 $ 50,000 1750 H Street, NW 3.69% 8/1/2024 32,000 Weighted Average/Total 3.93% $ 82,000 (1) Includes the effect of mark to market purchase accounting. (2) Reflects the entire balance of the debt secured by the properties and is not adjusted to reflect the interests in the joint ventures we do not own. None of the debt is recourse to us. At December 31, 2022, the aggregate unamortized basis difference of our two unconsolidated joint ventures of $6,489 was primarily attributable to the difference between the amount we paid to purchase our interest in these joint ventures, including transaction costs, and the historical carrying value of the net assets of these joint ventures. This difference is being amortized over the remaining useful life of the related properties and the resulting amortization expense is included in equity in net losses of investees in our consolidated statements of comprehensive income (loss).

Leases

Leases	12 Months Ended
Leases	Dec. 31, 2022
Leases [Abstract]
Leases	LeasesRental income from operating leases, including payments derived by index or market-based indices, is recognized on a straight line basis over the lease term when we have determined that the collectability of substantially all of the lease payments is probable. We increased rental income by $10,830, $15,368 and $16,079 to record revenue on a straight line basis during the years ended December 31, 2022, 2021 and 2020, respectively. Rents receivable, excluding properties classified as held for sale, include $86,305 and $82,978 of straight line rent receivables at December 31, 2022 and 2021, respectively. We do not include in our measurement of our lease receivables certain variable payments, including payments determined by changes in the index or market-based indices after the inception of the lease, certain tenant reimbursements and other income until the specific events that trigger the variable payments have occurred. Such payments totaled $83,103, $85,107 and $75,851 for the years ended December 31, 2022, 2021 and 2020, respectively, of which tenant reimbursements totaled $78,388, $81,295 and $71,385, respectively. The following operating lease maturity analysis presents the future contractual lease payments to be received by us through 2053 as of December 31, 2022: Year Amount 2023 $ 393,318 2024 358,254 2025 313,267 2026 279,820 2027 248,976 Thereafter 1,393,682 Total $ 2,987,317 As of December 31, 2022, tenants representing approximately 1.5% of our total operating lease maturities had exercisable rights to terminate their leases before the stated terms of their leases expire. In 2023, 2024, 2025, 2026, 2027, 2028, 2029, 2030, 2031, 2035, 2037 and 2040, early termination rights become exercisable by other tenants who represented an additional approximatel y 1.3%, 2.4%, 5.6%, 1.6%, 1.6%, 5.5%, 2.1%, 1.6%, 0.3%, 3.5%, 0.4% and 1.7% of our t otal operating lease maturities, respectively. In certain circumstances, some leases provide the tenant with the right to terminate if the legislature or other funding authority does not appropriate the funding necessary for the tenant to meet its lease obligations; we have determined the fixed non-cancelable lease term of these leases to be the full term of the lease because we believe the occurrence of early terminations to be a remote contingency based on both our historical experience and our assessments of the likelihood of lease cancellation on a separate lease basis. As of December 31, 2022, 10 of our tenants had the right to terminate their leases if the respective legislature or other funding authority does not appropriate the funding necessary for the tenant to meet its obligation. These 10 tenants represented approximately 4.8% of our total operating lease maturities as of December 31, 2022. Leases where we are the lessee. We had one lease where we were the lessee which expired on January 31, 2021. We subleased a portion of the space, which sublease also expired on January 31, 2021. Rent expense incurred under the lease, net of sublease revenue, was $79 and $1,749 for the years ended December 31, 2021 and 2020, respectively.
Leases	LeasesRental income from operating leases, including payments derived by index or market-based indices, is recognized on a straight line basis over the lease term when we have determined that the collectability of substantially all of the lease payments is probable. We increased rental income by $10,830, $15,368 and $16,079 to record revenue on a straight line basis during the years ended December 31, 2022, 2021 and 2020, respectively. Rents receivable, excluding properties classified as held for sale, include $86,305 and $82,978 of straight line rent receivables at December 31, 2022 and 2021, respectively. We do not include in our measurement of our lease receivables certain variable payments, including payments determined by changes in the index or market-based indices after the inception of the lease, certain tenant reimbursements and other income until the specific events that trigger the variable payments have occurred. Such payments totaled $83,103, $85,107 and $75,851 for the years ended December 31, 2022, 2021 and 2020, respectively, of which tenant reimbursements totaled $78,388, $81,295 and $71,385, respectively. The following operating lease maturity analysis presents the future contractual lease payments to be received by us through 2053 as of December 31, 2022: Year Amount 2023 $ 393,318 2024 358,254 2025 313,267 2026 279,820 2027 248,976 Thereafter 1,393,682 Total $ 2,987,317 As of December 31, 2022, tenants representing approximately 1.5% of our total operating lease maturities had exercisable rights to terminate their leases before the stated terms of their leases expire. In 2023, 2024, 2025, 2026, 2027, 2028, 2029, 2030, 2031, 2035, 2037 and 2040, early termination rights become exercisable by other tenants who represented an additional approximatel y 1.3%, 2.4%, 5.6%, 1.6%, 1.6%, 5.5%, 2.1%, 1.6%, 0.3%, 3.5%, 0.4% and 1.7% of our t otal operating lease maturities, respectively. In certain circumstances, some leases provide the tenant with the right to terminate if the legislature or other funding authority does not appropriate the funding necessary for the tenant to meet its lease obligations; we have determined the fixed non-cancelable lease term of these leases to be the full term of the lease because we believe the occurrence of early terminations to be a remote contingency based on both our historical experience and our assessments of the likelihood of lease cancellation on a separate lease basis. As of December 31, 2022, 10 of our tenants had the right to terminate their leases if the respective legislature or other funding authority does not appropriate the funding necessary for the tenant to meet its obligation. These 10 tenants represented approximately 4.8% of our total operating lease maturities as of December 31, 2022. Leases where we are the lessee. We had one lease where we were the lessee which expired on January 31, 2021. We subleased a portion of the space, which sublease also expired on January 31, 2021. Rent expense incurred under the lease, net of sublease revenue, was $79 and $1,749 for the years ended December 31, 2021 and 2020, respectively.

Business and Property Managemen

Business and Property Management Agreements with RMR	12 Months Ended
Business and Property Management Agreements with RMR	Dec. 31, 2022
Related Party Transactions [Abstract]
Business and Property Management Agreements with RMR	Business and Property Management Agreements with RMR We have no employees. The personnel and various services we require to operate our business are provided to us by The RMR Group LLC, or RMR. We have two agreements with RMR to provide management services to us: (1) a business management agreement, which relates to our business generally; and (2) a property management agreement, which relates to our property level operations. Management Agreements with RMR . Our management agreements with RMR provide for an annual base management fee, an annual incentive management fee and property management and construction supervision fees, payable in cash, among other terms: • Base Management Fee. The annual base management fee payable to RMR by us for each applicable period is equal to the lesser of: • the sum of (a) 0.5% of the average aggregate historical cost of the real estate assets acquired from a REIT to which RMR provided business management or property management services, or the Transferred Assets, plus (b) 0.7% of the average aggregate historical cost of our real estate investments excluding the Transferred Assets up to $250,000, plus (c) 0.5% of the average aggregate historical cost of our real estate investments excluding the Transferred Assets exceeding $250,000; and • the sum of (a) 0.7% of the average closing price per share of our common shares on the stock exchange on which such shares are principally traded during such period, multiplied by the average number of our common shares outstanding during such period, plus the daily weighted average of the aggregate liquidation preference of each class of our preferred shares outstanding during such period, plus the daily weighted average of the aggregate principal amount of our consolidated indebtedness during such period, or, together, our Average Market Capitalization, up to $250,000, plus (b) 0.5% of our Average Market Capitalization exceeding $250,000. The average aggregate historical cost of our real estate investments includes our consolidated assets invested, directly or indirectly, in equity interests in or loans secured by real estate and personal property owned in connection with such real estate (including acquisition related costs and costs which may be allocated to intangibles or are unallocated), all before reserves for depreciation, amortization, impairment charges or bad debts or other similar non-cash reserves. • Incentive Management Fee . The incentive management fee which may be earned by RMR for an annual period is calculated as follows: • An amount, subject to a cap based on the value of our common shares outstanding, equal to 12% of the product of: • our equity market capitalization on the last trading day of the year immediately prior to the relevant three • the amount (expressed as a percentage) by which the total return per share, as defined in the business management agreement and further described below, of our common shareholders (i.e., share price appreciation plus dividends) exceeds the total shareholder return of the applicable index, or the benchmark return per share, for the relevant measurement period. The MSCI U.S. REIT/Office REIT Index is the benchmark index for periods on and after August 1, 2021, and the SNL U.S. REIT Office Index is the benchmark index for periods prior to August 1, 2021. For purposes of the total return per share of our common shareholders, share price appreciation for a measurement period is determined by subtracting (1) the closing price of our common shares on The Nasdaq Stock Market LLC, or Nasdaq, on the last trading day of the year immediately before the first year of the applicable measurement period, or the initial share price, from (2) the average closing price of our common shares on the 10 consecutive trading days having the highest average closing prices during the final 30 trading days in the last year of the measurement period. • The calculation of the incentive management fee (including the determinations of our equity market capitalization, initial share price and the total return per share of our common shareholders) is subject to adjustments if we issue or repurchase our common shares, or if our common shares are forfeited, during the measurement period. • No incentive management fee is payable by us unless our total return per share during the measurement period is positive. • The measurement periods are three year • If our total return per share exceeds 12% per year in any measurement period, the benchmark return per share is adjusted to be the lesser of the total shareholder return of the applicable index for such measurement period and 12% per year, or the adjusted benchmark return per share. In instances where the adjusted benchmark return per share applies, the incentive management fee will be reduced if our total return per share is between 200 basis points and 500 basis points below the applicable index in any year by a low return factor, as defined in the business management agreement, and there will be no incentive management fee paid if, in these instances, our total return per share is more than 500 basis points below the applicable index in any year, determined on a cumulative basis (i.e., between 200 basis points and 500 basis points per year multiplied by the number of years in the measurement period and below the applicable market index). • The incentive management fee is subject to a cap. The cap is equal to the value of the number of our common shares which would, after issuance, represent 1.5% of the number of our common shares then outstanding multiplied by the average closing price of our common shares during the 10 consecutive trading days having the highest average closing prices during the final 30 trading days of the relevant measurement period. • Incentive management fees we paid to RMR for any period may be subject to “clawback” if our financial statements for that period are restated due to material non-compliance with any financial reporting requirements under the securities laws as a result of the bad faith, fraud, willful misconduct or gross negligence of RMR and the amount of the incentive management fee we paid was greater than the amount we would have paid based on the restated financial statements. Pursuant to our business management agreement with RMR, we recognized net business management fees of $17,376, $18,637 and $17,358 for the years ended December 31, 2022, 2021 and 2020, respectively. The net business management fees we recognized are included in general and administrative expenses in our consolidated statements of comprehensive income (loss) for these periods. The net business management fees we recognized for each of the years ended December 31, 2022, 2021 and 2020 reflect a reduction of $603, for the amortization of the liability we recorded in connection with our former investment in RMR Inc., as further described in Note 2. We did not incur any incentive management fee pursuant to our business management agreement for the years ended December 31, 2022, 2021 or 2020. • Property Management and Construction Supervision Fees . The property management fees payable to RMR by us for each applicable period are equal to 3.0% of gross collected rents and the construction supervision fees payable to RMR by us for each applicable period are equal to 5.0% of construction costs. Pursuant to our property management agreement with RMR, we recognized aggregate net property management and construction supervision fees of $25,756, $21,103 and $20,774 for each of the years ended December 31, 2022, 2021 and 2020, respectively. The net property management and construction supervision fees we recognized for the years ended December 31, 2022, 2021 and 2020 reflect a reduction of $484 for each of those years for the amortization of the liability we recorded in connection with our former investment in RMR Inc., as further described in Note 2. For the years ended December 31, 2022, 2021 and 2020, $15,839, $16,507 and $17,328, respectively, of the total net property management and construction supervision fees were expensed to other operating expenses in our consolidated statements of income (loss) and $9,917, $4,596 and $3,446, respectively, were capitalized as building improvements in our consolidated balance sheets. The amounts capitalized are being depreciated over the estimated useful lives of the related capital assets. • Expense Reimbursement . We are generally responsible for all of our operating expenses, including certain expenses incurred or arranged by RMR on our behalf. We are generally not responsible for payment of RMR’s employment, office or administrative expenses incurred to provide management services to us, except for the employment and related expenses of RMR’s employees assigned to work exclusively or partly at our properties, our share of the wages, benefits and other related costs of RMR’s centralized accounting personnel, our share of RMR’s costs for providing our internal audit function and as otherwise agreed. Our property level operating expenses are generally incorporated into rents charged to our tenants, including certain payroll and related costs incurred by RMR. We reimbursed RMR $24,371 , $24,766 and $24,919 for these expenses and costs for each of the years ended December 31, 2022, 2021 and 2020, respectively. We included these amounts in other operating expenses and general and administrative expense, as applicable, for these periods. • Term . Our management agreements with RMR have terms that end on December 31, 2042, and automatically extend on December 31st of each year for an additional year, so that the terms of our management agreements thereafter end on the 20th anniversary of the date of the extension. • Termination Rights . We have the right to terminate one or both of our management agreements with RMR: (i) at any time on 60 days’ written notice for convenience, (ii) immediately on written notice for cause, as defined therein, (iii) on written notice given within 60 days after the end of an applicable calendar year for a performance reason, as defined therein, and (iv) by written notice during the 12 months following a change of control of RMR, as defined therein. RMR has the right to terminate the management agreements for good reason, as defined therein. • Termination Fee . If we terminate one or both of our management agreements with RMR for convenience, or if RMR terminates one or both of our management agreements for good reason, we have agreed to pay RMR a termination fee in an amount equal to the sum of the present values of the monthly future fees, as defined therein, for the terminated management agreement(s) for the term that was remaining prior to such termination, which, depending on the time of termination, would be between 19 and 20 years. If we terminate one or both of our management agreements with RMR for a performance reason, we have agreed to pay RMR the termination fee calculated as described above, but assuming a 10-year term was remaining prior to the termination. We are not required to pay any termination fee if we terminate our management agreements with RMR for cause or as a result of a change of control of RMR. • Transition Services . RMR has agreed to provide certain transition services to us for 120 days following an applicable termination by us or notice of termination by RMR, including cooperating with us and using commercially reasonable efforts to facilitate the orderly transfer of the management and real estate investment services provided under our business management agreement and to facilitate the orderly transfer of the management of the managed properties under our property management agreement, as applicable. • Vendors . Pursuant to our management agreements with RMR, RMR may from time to time negotiate on our behalf with certain third party vendors and suppliers for the procurement of goods and services to us. As part of this arrangement, we may enter agreements with RMR and other companies to which RMR or its subsidiaries provide management services for the purpose of obtaining more favorable terms from such vendors and suppliers. • Investment Opportunities . Under our business management agreement with RMR, we acknowledge that RMR may engage in other activities or businesses and act as the manager to any other person or entity (including other REITs) even though such person or entity has investment policies and objectives similar to ours and we are not entitled to preferential treatment in receiving information, recommendations and other services from RMR. Management Agreements between our Joint Ventures and RMR . RMR provides management services to our two unconsolidated joint ventures. We are not obligated to pay management fees to RMR under our management agreements with RMR for the services it provides regarding the joint ventures. The joint ventures pay management fees directly to RMR.

Related Person Transactions

Related Person Transactions	12 Months Ended
Related Person Transactions	Dec. 31, 2022
Related Party Transactions [Abstract]
Related Person Transactions	Related Person Transactions We have relationships and historical and continuing transactions with RMR, RMR Inc., and others related to them, including other companies to which RMR or its subsidiaries provide management services and some of which have trustees, directors or officers who are also our Trustees or officers. RMR is a majority owned subsidiary of RMR Inc. The Chair of our Board of Trustees and one of our Managing Trustees, Adam Portnoy, is the sole trustee, an officer and the controlling shareholder of ABP Trust, which is the controlling shareholder of RMR Inc., the chair of the board of directors, a managing director, the president and chief executive officer of RMR Inc. and an officer and employee of RMR. Jennifer Clark, our other Managing Trustee, is a managing director and the executive vice president, general counsel and secretary of RMR Inc., an officer and employee of RMR and an officer of ABP Trust. Each of our officers is also an officer and employee of RMR. Some of our Independent Trustees also serve as independent trustees or independent directors of other public companies to which RMR or its subsidiaries provide management services. Mr. Portnoy serves as chair of the boards and as a managing director or managing trustee of these public companies. Other officers of RMR, including Ms. Clark, serve as managing trustees, managing directors or officers of certain of these companies. Our Manager, RMR . We have two agreements with RMR to provide management services to us. RMR also provides management services to our unconsolidated joint ventures. See Note 6 for more information regarding our and our unconsolidated joint ventures’ management agreements with RMR. Leases with RMR . We lease office space to RMR in certain of our properties for RMR’s property management offices. Pursuant to our lease agreements with RMR, we recognized rental income from RMR for leased office space of $1,126, $1,138 and $1,120 for the years ended December 31, 2022, 2021 and 2020, respectively. Our office space leases with RMR are terminable by RMR if our management agreements with RMR are terminated. Share Awards to RMR Employees . As described further in Note 11, we award shares to our officers and other employees of RMR annually. Generally, one fifth of these awards vest on the grant date and one fifth vests on each of the next four Sonesta . In June 2021, we entered into a 30-year lease agreement with a subsidiary of Sonesta International Hotels Corporation, or Sonesta, in connection with the redevelopment of an office property we own in Washington, D.C. as a mixed-

Concentration

Concentration	12 Months Ended
Concentration	Dec. 31, 2022
Risks and Uncertainties [Abstract]
Concentration	Concentration Tenant and Credit Concentration We define annualized rental income as the annualized contractual base rents from our tenants pursuant to our lease agreements as of the measurement date, plus straight line rent adjustments and estimated recurring expense reimbursements to be paid to us, and excluding lease value amortization. As of December 31, 2022, 2021 and 2020, the U.S. government and certain state and other government tenants combined were responsible for approximately 28.5%, 28.9% and 35.3%, respectively, of our annualized rental income. The U.S. government is our largest tenant by annualized rental income and represented approximately 19.7%, 19.5%, and 25.2% of our annualized rental income as of December 31, 2022, 2021 and 2020, respectively. Geographic Concentration At December 31, 2022, our 160 wholly owned properties were located in 30 states and the District of Columbia. Properties located in California, Virginia, Illinois, the District of Columbia and Georgia were responsible for approximately 11.7%, 11.0%, 10.8%, 10.5%, and 9.0% of our annualized rental income as of December 31, 2022, respectively.

Indebtedness

Indebtedness	12 Months Ended
Indebtedness	Dec. 31, 2022
Debt Disclosure [Abstract]
Indebtedness	Indebtedness At December 31, 2022 and 2021, our outstanding indebtedness consisted of the following: December 31, 2022 2021 Revolving credit facility, due in 2023 $ 195,000 $ — Senior unsecured notes, 4.00% interest rate, due in 2022 (1) — 300,000 Senior unsecured notes, 4.25% interest rate, due in 2024 350,000 350,000 Senior unsecured notes, 4.50% interest rate, due in 2025 650,000 650,000 Senior unsecured notes, 2.650% interest rate, due in 2026 300,000 300,000 Senior unsecured notes, 2.400% interest rate, due in 2027 350,000 350,000 Senior unsecured notes, 3.450% interest rate, due in 2031 400,000 400,000 Senior unsecured notes, 6.375% interest rate, due in 2050 162,000 162,000 Mortgage note payable, 4.220% interest rate, due in 2022 (2) — 25,055 Mortgage note payable, 3.700% interest rate, due in 2023 50,000 50,000 Mortgage note payable, 4.800% interest rate, due in 2023 (3) — 23,246 2,457,000 2,610,301 Unamortized debt premiums, discounts and issuance costs (24,208) (32,351) $ 2,432,792 $ 2,577,950 (1) These senior notes were redeemed in June 2022. (2) This mortgage note was prepaid, at par plus accrued interest, in April 2022. (3) This mortgage note was prepaid, at a discounted amount of $22,176 plus accrued interest, in October 2022. Our $750,000 revolving credit facility is governed by a credit agreement, or our credit agreement, with a syndicate of institutional lenders that includes a feature under which the maximum aggregate borrowing availability may be increased to up to $1,950,000 in certain circumstances. Our $750,000 revolving credit facility is available for general business purposes, including acquisitions. In November 2022, we exercised our option to extend the maturity date of our revolving credit facility to July 31, 2023 and paid an extension fee of $469 and, subject to our payment of an extension fee and meeting certain other conditions, we have the option to extend the maturity date of our revolving credit facility by one additional six month period. We can borrow, repay and reborrow funds available under our revolving credit facility until maturity and no principal repayment is due until maturity. We are required to pay interest at a rate of LIBOR plus a premium, which was 110 basis points per annum at December 31, 2022, on the amount outstanding under our revolving credit facility. We also pay a facility fee on the total amount of lending commitments under our revolving credit facility, which was 25 basis points per annum at December 31, 2022. Both the interest rate premium and facility fee are subject to adjustment based upon changes to our credit ratings. As of December 31, 2022 and 2021, the annual interest rate payable on borrowings under our revolving credit facility was 5.4% and 1.2%, respectively. The weighted average annual interest rate for borrowings under our revolving credit facility was 4.0%, 1.2% and 2.0% for the years ended December 31, 2022, 2021 and 2020, respectively. As of December 31, 2022 and February 14, 2023, we had $195,000 and $220,000, respectively, outstanding under our revolving credit facility and $555,000 and $530,000, respectively, available for borrowing. Our credit agreement and senior unsecured notes indentures and their supplements provide for acceleration of payment of all amounts due thereunder upon the occurrence and continuation of certain events of default, such as, in the case of our credit agreement, a change of control of us, which includes RMR ceasing to act as our business and property manager. Our credit agreement and senior unsecured notes indentures and their supplements also contain covenants, including covenants that restrict our ability to incur debts, require us to comply with certain financial covenants and, in the case of our credit agreement, restrict our ability to make distributions under certain circumstances. We believe we were in compliance with the terms and conditions of the respective covenants under our credit agreement and senior unsecured notes indentures and their supplements at December 31, 2022. Senior Unsecured Note Redemption In June 2022, we redeemed, at par plus accrued interest, all $300,000 of our 4.00% senior unsecured notes due July 2022. As a result of this redemption, we recognized a loss on early extinguishment of debt of $77 during the year ended December 31, 2022, from the write off of unamortized discounts and debt issuance costs. Mortgage Note Prepayments In April 2022, we prepaid, at par plus accrued interest, a mortgage note secured by one property with an outstanding principal balance of $24,863, an annual interest rate of 4.22% and a maturity date in July 2022. In October 2022, we prepaid, at a discounted amount of $22,176 plus accrued interest, a mortgage note secured by one property with an outstanding principal balance of $22,901, an annual interest rate of 4.80% and a maturity date in June 2023. As a result of this discounted prepayment, we recognized a gain on early extinguishment of debt of $759 during the year ended December 31, 2022, after the write off of unamortized premiums and debt issuance costs. At December 31, 2022, one of our properties with a net book value of $55,071 was encumbered by a mortgage note with a principal balance of $50,000. Our mortgage note is non-recourse, subject to certain limited exceptions, and does not contain any material financial covenants. None of our unsecured debt obligations require sinking fund payments prior to their maturity dates. The required principal payments due during the next five years and thereafter under all our outstanding consolidated debt as of December 31, 2022 were as follows: Year Principal Payment 2023 $ 245,000 2024 350,000 2025 650,000 2026 300,000 2027 350,000 Thereafter 562,000 Total $ 2,457,000 (1) (1) Total consolidated debt outstanding as of December 31, 2022, net of unamortized premiums, discounts and issuance costs totaling $24,208, was $2,432,792.

Fair Value of Assets and Liabil

Fair Value of Assets and Liabilities	12 Months Ended
Fair Value of Assets and Liabilities	Dec. 31, 2022
Fair Value Disclosures [Abstract]
Fair Value of Assets and Liabilities	Fair Value of Assets and Liabilities Our financial instruments include our cash and cash equivalents, restricted cash, rents receivable, accounts payable, a revolving credit facility, senior unsecured notes, a mortgage note payable, amounts due to related persons, other accrued expenses and security deposits. At December 31, 2022 and 2021, the fair values of our financial instruments approximated their carrying values in our consolidated financial statements, due to their short term nature or floating interest rates, except as follows: As of December 31, 2022 As of December 31, 2021 Financial Instrument Carrying Value (1) Fair Value Carrying Value (1) Fair Value Senior unsecured notes, 4.00% interest rate, due in 2022 (2) $ — $ — $ 299,500 $ 304,148 Senior unsecured notes, 4.25% interest rate, due in 2024 346,863 331,601 344,581 365,449 Senior unsecured notes, 4.50% interest rate, due in 2025 642,818 589,388 639,370 687,749 Senior unsecured notes, 2.650% interest rate, due in 2026 297,839 232,770 297,213 298,502 Senior unsecured notes, 2.400% interest rate, due in 2027 347,466 256,606 346,845 339,764 Senior unsecured notes, 3.450% interest rate, due in 2031 396,178 268,004 395,744 388,458 Senior unsecured notes, 6.375% interest rate, due in 2050 156,711 113,075 156,519 177,098 Mortgage notes payable (3) 49,917 49,099 98,178 100,294 Total $ 2,237,792 $ 1,840,543 $ 2,577,950 $ 2,661,462 (1) Includes unamortized debt premiums, discounts and issuance costs totaling $24,208 and $32,351 as of December 31, 2022 and 2021, respectively. (2) These senior notes were redeemed in June 2022. (3) Balance as of December 31, 2021 includes a mortgage note secured by one property with an outstanding principal amount of $25,055 that was prepaid, at par plus accrued interest, in April 2022 and a mortgage note secured by one property with an outstanding principal balance of $23,246 that was prepaid, at a discounted amount of $22,176 plus accrued interest, in October 2022. We estimated the fair values of our senior unsecured notes (except for our senior unsecured notes due 2050) using an average of the bid and ask price of the notes (Level 2 inputs as defined in the fair value hierarchy under GAAP) as of the measurement date. We estimated the fair values of our senior unsecured notes due 2050 based on the closing price on Nasdaq (Level 1 inputs as defined in the fair value hierarchy under GAAP) as of the measurement date. We estimated the fair values of our mortgage notes payable using discounted cash flow analyses and currently prevailing market rates (Level 3 inputs as defined in the fair value hierarchy under GAAP) as of the measurement date. Because Level 3 inputs are unobservable, our estimated fair values may differ materially from the actual fair values.

Shareholders' Equity

Shareholders' Equity	12 Months Ended
Shareholders' Equity	Dec. 31, 2022
Equity [Abstract]
Shareholders' Equity	Shareholders’ Equity Share Awards We have common shares available for issuance under the terms of our Amended and Restated 2009 Incentive Share Award Plan, or the 2009 Plan. During the years ended December 31, 2022, 2021 and 2020, we awarded to our officers and other employees of RMR annual share awards of 141,200, 117,800 and 108,600 of our common shares, respectively, valued at $2,470, $2,994 and $2,502, in aggregate, respectively. We also awarded each of our then Tr ustees 3,500 of our common shares in each of 2022, 2021 and 2020 as part of their annual compensation. These awards had aggregate values of $593 ($66 per Trustee), $837 ($105 p er Trustee) and $745 ($93 per Trustee) in 2022, 2021 and 2020, respectively. The values of the share awards were based upon the closing price of our common shares trading on Nasdaq on the date of award. The common shares awarded to our officers and certain other employees of RMR vest in five equal annual installments beginning on the date of award. The common shares awarded to our Trustees vest immediately. We recognize share forfeitures as they occur and include the value of awarded shares in general and administrative expenses ratably over the vesting period. A summary of shares awarded, forfeited, vested and unvested under the terms of the 2009 Plan for the years ended December 31, 2022, 2021 and 2020, is as follows: 2022 2021 2020 Number of Shares Weighted Average Grant Date Fair Value Number of Shares Weighted Average Grant Date Fair Value Number of Shares Weighted Average Grant Date Fair Value Unvested at beginning of year 182,224 $ 26.23 157,521 $ 29.26 106,680 $ 40.16 Awarded 172,700 $ 17.74 145,800 $ 26.28 136,600 $ 23.77 Forfeited (1,900) $ 25.97 (700) $ 25.97 (586) $ 43.75 Vested (121,723) $ 23.24 (120,397) $ 30.24 (85,173) $ 34.02 Unvested at end of year 231,301 $ 21.47 182,224 $ 26.23 157,521 $ 29.26 The 231,301 unvested shares as of December 31, 2022 are scheduled to vest as follows: 84,941 shares in 2023, 67,620 shares in 2024, 50,500 shares in 2025 and 28,240 shares in 2026. As of December 31, 2022, the estimated future compensation expense for the unvested shares was $4,343. The weighted average period over which the compensation expense will be recorded is approximately 22 months. During the years ended December 31, 2022, 2021 and 2020, we recorded $2,905, $2,868 and $3,315, respectively, of compensation expense related to the 2009 Plan. At December 31, 2022, 847,631 of our common shares remained available for issuance under the 2009 Plan. Share Purchases During the years ended December 31, 2022, 2021 and 2020, w e purchased 30,821, 37,801 and 19,589 of o ur common shares, respectively, valued at weighted average sh are prices of $17.54, $26.55 and $22.15 per c ommon share, respectively, from certain of our current and former Trustees and officers and certain current and former officers and employees of RMR in satisfaction of tax withholding and payment obligations in connection with the vesting of awards of our common shares. Distributions During the years ended December 31, 2022, 2021 and 2020, we paid distributions on our common shares as follows: Annual Per Share Distribution Total Distributions Characterization of Distributions Year Return of Capital Ordinary Income Qualified Dividend 2022 $ 2.20 $ 106,630 62.68% 37.32% —% 2021 $ 2.20 $ 106,368 —% 100.00% —% 2020 $ 2.20 $ 106,121 —% 100.00% —% On January 12, 2023, we declared a regular quarterly distribution payable to common shareholders of record on January 23, 2023 in the amount of $0.55 per share, or approximately $26,700. We expect to pay this distribution on or about February 16, 2023.

SCHEDULE III REAL ESTATE AND AC

SCHEDULE III REAL ESTATE AND ACCUMULATED DEPRECIATION	12 Months Ended
SCHEDULE III REAL ESTATE AND ACCUMULATED DEPRECIATION	Dec. 31, 2022
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation Disclosure [Abstract]
SCHEDULE III REAL ESTATE AND ACCUMULATED DEPRECIATION	Initial Cost to Company Costs Capitalized Subsequent to Acquisition Cost amount carried at Close of Period Property Location Number of Properties Encumbrances (1) Land Buildings Impairments/ Land Buildings Total (2) Accumulated (3) Date(s) Original 445 Jan Davis Drive Huntsville, AL 1 $ — $ 1,501 $ 1,492 $ — $ — $ 1,501 $ 1,492 $ 2,993 $ (160) 12/31/2018 2007 131 Clayton Street Montgomery, AL 1 — 920 9,084 417 — 920 9,501 10,421 (2,690) 6/22/2011 2007 4344 Carmichael Road Montgomery, AL 1 — 1,374 11,658 562 — 1,374 12,220 13,594 (2,766) 12/17/2013 2009 15451 North 28th Avenue Phoenix, AZ 1 — 1,917 7,416 765 — 1,917 8,181 10,098 (1,756) 9/10/2014 1996 16001 North 28th Avenue Phoenix, AZ 1 — 3,355 412 1,146 — 3,355 1,558 4,913 (273) 12/31/2018 1998 711 S 14th Avenue Safford, AZ 1 — 460 11,708 884 (4,440) 364 8,248 8,612 (1,381) 6/16/2010 1992 Regents Center Tempe, AZ 2 — 4,121 3,042 293 — 4,121 3,335 7,456 (660) 12/31/2018 1988 Campbell Place Carlsbad, CA 2 — 5,769 3,871 7,517 — 5,769 11,388 17,157 (2,438) 12/31/2018 2007 Folsom Corporate Center Folsom, CA 1 — 2,904 5,583 1,567 — 2,904 7,150 10,054 (816) 12/31/2018 2008 Bayside Technology Park Fremont, CA 1 — 10,784 648 198 — 10,784 846 11,630 (110) 12/31/2018 1990 10949 N. Mather Boulevard Rancho Cordova, CA 1 — 562 16,923 1,012 — 562 17,935 18,497 (4,165) 10/30/2013 2012 11020 Sun Center Drive Rancho Cordova, CA 1 — 1,466 8,797 1,409 — 1,466 10,206 11,672 (1,827) 12/20/2016 1983 100 Redwood Shores Parkway Redwood City, CA 1 — 14,454 7,721 — — 14,454 7,721 22,175 (857) 12/31/2018 1993 3875 Atherton Road Rocklin, CA 1 — 177 853 23 — 177 876 1,053 (95) 12/31/2018 1991 801 K Street Sacramento, CA 1 — 4,688 61,994 9,465 — 4,688 71,459 76,147 (12,968) 1/29/2016 1989 9815 Goethe Road Sacramento, CA 1 — 1,450 9,465 1,603 — 1,450 11,068 12,518 (3,109) 9/14/2011 1992 Capitol Place Sacramento, CA 1 — 2,290 35,891 8,767 — 2,290 44,658 46,948 (14,418) 12/17/2009 1988 4560 Viewridge Road San Diego, CA 1 — 4,269 18,316 5,146 — 4,347 23,384 27,731 (13,942) 3/31/1997 1996 2115 O’Nel Drive San Jose, CA 1 — 12,305 5,062 350 — 12,305 5,412 17,717 (587) 12/31/2018 1984 North First Street San Jose, CA 1 — 8,311 4,003 411 — 8,311 4,414 12,725 (572) 12/31/2018 1984 Rio Robles Drive San Jose, CA 3 — 23,687 13,698 12,637 — 23,687 26,335 50,022 (2,332) 12/31/2018 1984 2450 and 2500 Walsh Avenue Santa Clara, CA 2 — 13,374 16,651 194 — 13,374 16,845 30,219 (1,878) 12/31/2018 1982 3250 and 3260 Jay Street Santa Clara, CA 2 — 19,899 14,051 20 — 19,899 14,071 33,970 (1,558) 12/31/2018 1982 603 San Juan Avenue Stockton, CA 1 — 563 5,470 93 — 563 5,563 6,126 (1,436) 7/20/2012 2012 350 West Java Drive Sunnyvale, CA 1 — 24,609 462 408 — 24,609 870 25,479 (93) 12/31/2018 1984 7958 South Chester Street Centennial, CO 1 — 6,682 7,153 1,410 — 6,682 8,563 15,245 (924) 12/31/2018 2000 350 Spectrum Loop Colorado Springs, CO 1 — 3,650 7,732 573 — 3,650 8,305 11,955 (933) 12/31/2018 2000 12795 West Alameda Parkway Lakewood, CO 1 — 2,640 23,777 1,535 — 2,640 25,312 27,952 (8,177) 1/15/2010 1988 Corporate Center Lakewood, CO 3 — 2,887 27,537 2,689 — 2,887 30,226 33,113 (14,630) 10/11/2002 1980 Initial Cost to Company Costs Capitalized Subsequent to Acquisition Cost amount carried at Close of Period Property Location Number of Properties Encumbrances (1) Land Buildings Impairments/ Land Buildings Total (2) Accumulated (3) Date(s) Original 11 Dupont Circle, NW Washington, DC 1 — 28,255 44,743 18,712 — 28,255 63,455 91,710 (10,002) 10/2/2017 1974 1211 Connecticut Avenue, NW Washington, DC 1 — 30,388 24,667 3,871 — 30,388 28,538 58,926 (4,681) 10/2/2017 1967 1401 K Street, NW Washington, DC 1 — 29,215 34,656 7,146 — 29,215 41,802 71,017 (7,675) 10/2/2017 1929 20 Massachusetts Avenue Washington, DC 1 — 12,009 51,527 178,984 — 12,231 230,289 242,520 (42,535) 3/31/1997 1996 440 First Street, NW Washington, DC 1 — 27,903 38,624 2,315 — 27,903 40,939 68,842 (5,678) 10/2/2017 1982 625 Indiana Avenue Washington, DC 1 — 26,000 25,955 10,652 — 26,000 36,607 62,607 (10,956) 8/17/2010 1989 840 First Street, NE Washington, DC 1 — 42,727 73,278 3,949 — 42,727 77,227 119,954 (11,073) 10/2/2017 2003 10350 NW 112th Avenue Miami, FL 1 — 4,798 2,757 1,903 — 4,798 4,660 9,458 (441) 12/31/2018 2002 7850 Southwest 6th Court Plantation, FL 1 — 4,800 30,592 1,167 — 4,800 31,759 36,559 (9,022) 5/12/2011 1999 8900 Grand Oak Circle Tampa, FL 1 — 1,100 11,773 1,142 — 1,100 12,915 14,015 (3,830) 10/15/2010 1994 180 Ted Turner Drive SW Atlanta, GA 1 — 5,717 20,017 726 — 5,717 20,743 26,460 (5,401) 7/25/2012 2007 1224 Hammond Drive Atlanta, GA 1 — 13,040 135,459 11,627 — 13,040 147,086 160,126 (6,189) 6/25/2021 2020 Corporate Square Atlanta, GA 5 — 3,996 29,762 28,076 — 3,996 57,838 61,834 (20,701) 7/16/2004 1967 Executive Park Atlanta, GA 1 — 1,521 11,826 4,123 — 1,521 15,949 17,470 (8,424) 7/16/2004 1972 One Georgia Center Atlanta, GA 1 — 10,250 27,933 18,781 — 10,250 46,714 56,964 (11,782) 9/30/2011 1968 One Primerica Parkway Duluth, GA 1 — 6,927 22,951 — — 6,927 22,951 29,878 (2,545) 12/31/2018 2013 4712 Southpark Boulevard Ellenwood, GA 1 — 1,390 19,635 248 — 1,390 19,883 21,273 (5,152) 7/25/2012 2005 8305 NW 62nd Avenue Johnston, IA 1 — 2,649 7,997 — — 2,649 7,997 10,646 (887) 12/31/2018 2011 1185, 1249 & 1387 S. Vinnell Way Boise, ID 3 — 3,390 29,026 1,101 — 3,390 30,127 33,517 (7,835) 9/11/2012 1996; 1997; 2002 2020 S. Arlington Heights Arlington Heights, IL 1 — 1,450 13,588 2,139 — 1,450 15,727 17,177 (4,654) 12/29/2009 1988 400 South Jefferson Street Chicago, IL 1 49,917 19,379 20,115 783 — 19,379 20,898 40,277 (2,381) 12/31/2018 1947 1000 W. Fulton Chicago, IL 1 — 42,935 252,914 94 — 42,935 253,008 295,943 (12,816) 6/24/2021 2015 HUB 1415 Naperville, IL 1 — 12,333 20,586 16,211 — 12,333 36,797 49,130 (4,616) 12/31/2018 2001 440 North Fairway Drive Vernon Hills, IL 1 — 4,465 441 10 — 4,465 451 4,916 (51) 12/31/2018 1992 7601 and 7635 Interactive Way Indianapolis, IN 2 — 3,337 14,522 34 — 3,337 14,556 17,893 (1,517) 12/31/2018 2003 Intech Park Indianapolis, IN 3 — 4,170 69,759 10,389 — 4,170 80,148 84,318 (23,417) 10/14/2011 2000; 2001; 2008 7125 Industrial Road Florence, KY 1 — 1,698 11,722 293 — 1,698 12,015 13,713 (3,030) 12/31/2012 1980 251 Causeway Street Boston, MA 3 — 26,851 36,756 4,662 — 26,851 41,418 68,269 (7,688) 8/17/2010 1987 Initial Cost to Company Costs Capitalized Subsequent to Acquisition Cost amount carried at Close of Period Property Location Number of Properties Encumbrances (1) Land Buildings Impairments/ Land Buildings Total (2) Accumulated (3) Date(s) Original 300 Billerica Road Chelmsford, MA 1 — 2,223 — 45 — 2,223 45 2,268 (13) 12/31/2018 1984 330 Billerica Road Chelmsford, MA 1 — 2,477 — 10,103 — 2,477 10,103 12,580 (1,113) 12/31/2018 1984 75 Pleasant Street Malden, MA 1 — 1,050 31,086 856 — 1,050 31,942 32,992 (10,300) 5/24/2010 2008 25 Newport Avenue Quincy, MA 1 — 2,700 9,199 2,143 — 2,700 11,342 14,042 (3,154) 2/16/2011 1985 314 Littleton Road Westford, MA 1 — 5,691 8,487 100 — 5,691 8,587 14,278 (956) 12/31/2018 2007 Annapolis Commerce Center Annapolis, MD 2 — 4,057 7,665 4,628 — 4,057 12,293 16,350 (1,679) 10/2/2017 1989 4201 Patterson Avenue Baltimore, MD 1 — 901 8,097 4,134 (85) 893 12,154 13,047 (6,744) 10/15/1998 1989 7001 Columbia Gateway Drive Columbia, MD 1 — 5,642 10,352 569 — 5,642 10,921 16,563 (1,271) 12/31/2018 2008 Hillside Center Columbia, MD 2 — 3,437 4,228 971 — 3,437 5,199 8,636 (859) 10/2/2017 2001 TenThreeTwenty Columbia, MD 1 — 3,126 16,361 3,681 — 3,126 20,042 23,168 (2,782) 10/2/2017 1982 3300 75th Avenue Landover, MD 1 — 4,110 36,371 3,302 — 4,110 39,673 43,783 (12,615) 2/26/2010 1985 Redland 520/530 Rockville, MD 3 — 12,714 61,377 6,951 — 12,714 68,328 81,042 (8,937) 10/2/2017 2008 Redland 540 Rockville, MD 1 — 10,740 17,714 6,231 — 10,740 23,945 34,685 (5,635) 10/2/2017 2003 Rutherford Business Park Windsor Mill, MD 1 — 1,598 10,219 545 — 1,598 10,764 12,362 (2,741) 11/16/2012 1972 3550 Green Court Ann Arbor, MI 1 — 3,630 4,857 — — 3,630 4,857 8,487 (571) 12/31/2018 1998 11411 E. Jefferson Avenue Detroit, MI 1 — 630 18,002 567 — 630 18,569 19,199 (5,839) 4/23/2010 2009 Rosedale Corporate Plaza Roseville, MN 1 — 672 6,045 1,547 — 672 7,592 8,264 (4,636) 12/1/1999 1987 1300 Summit Street Kansas City, MO 1 — 2,776 12,070 900 — 2,776 12,970 15,746 (3,334) 9/27/2012 1998 2555 Grand Boulevard Kansas City, MO 1 — 4,209 51,522 4,778 — 4,209 56,300 60,509 (6,356) 12/31/2018 2003 4241 NE 34th Street Kansas City, MO 1 — 1,133 5,649 4,908 — 1,470 10,220 11,690 (5,127) 3/31/1997 1995 1220 Echelon Parkway Jackson, MS 1 — 440 25,458 561 — 440 26,019 26,459 (6,800) 7/25/2012 2009 2300 and 2400 Yorkmont Road Charlotte, NC 2 — 1,334 19,075 3,200 — 1,334 22,275 23,609 (2,725) 12/31/2018 1995 18010 and 18020 Burt Street Omaha, NE 2 — 6,977 12,500 — — 6,977 12,500 19,477 (1,386) 12/31/2018 2012 500 Charles Ewing Boulevard Ewing, NJ 1 — 4,808 26,002 281 — 4,808 26,283 31,091 (2,883) 12/31/2018 2012 299 Jefferson Road Parsippany, NJ 1 — 4,543 2,914 935 — 4,543 3,849 8,392 (554) 12/31/2018 2011 One Jefferson Road Parsippany, NJ 1 — 4,415 5,249 63 — 4,415 5,312 9,727 (588) 12/31/2018 2009 Airline Corporate Center Colonie, NY 1 — 790 6,400 1,827 — 790 8,227 9,017 (1,876) 6/22/2012 2004 1212 Pittsford - Victor Road Pittsford, NY 1 — 608 78 847 — 608 925 1,533 (106) 12/31/2018 1965 Initial Cost to Company Costs Capitalized Subsequent to Acquisition Cost amount carried at Close of Period Property Location Number of Properties Encumbrances (1) Land Buildings Impairments/ Land Buildings Total (2) Accumulated (3) Date(s) Original 2231 Schrock Road Columbus, OH 1 — 716 217 578 — 716 795 1,511 (98) 12/31/2018 1999 8800 Tinicum Boulevard Philadelphia, PA 1 — 5,573 22,686 5,934 — 5,573 28,620 34,193 (2,738) 12/31/2018 2000 446 Wrenplace Road Fort Mill, SC 1 — 5,031 22,524 — — 5,031 22,524 27,555 (1,140) 12/22/2020 2019 9680 Old Bailes Road Fort Mill, SC 1 — 834 2,944 53 — 834 2,997 3,831 (333) 12/31/2018 2007 16001 North Dallas Parkway Addison, TX 2 — 10,282 63,071 1,911 — 10,282 64,982 75,264 (7,529) 12/31/2018 1987 Research Park Austin, TX 2 — 4,258 13,747 199 — 4,258 13,946 18,204 (2,787) 12/31/2018 1999 10451 Clay Road Houston, TX 1 — 5,495 10,253 2,432 — 5,495 12,685 18,180 (1,139) 12/31/2018 2013 202 North Castlegory Road Houston, TX 1 — 863 5,024 8 — 863 5,032 5,895 (524) 12/31/2018 2016 4221 W. John Carpenter Freeway Irving, TX 1 — 1,413 2,365 1,843 — 1,413 4,208 5,621 (1,091) 12/31/2018 1995 8675, 8701-8711 Freeport Pkwy and 8901 Esters Boulevard Irving, TX 3 — 10,185 31,566 68 — 10,185 31,634 41,819 (3,500) 12/31/2018 1990 1511 East Common Street New Braunfels, TX 1 — 4,965 1,266 251 — 4,965 1,517 6,482 (223) 12/31/2018 2005 2900 West Plano Parkway Plano, TX 1 — 6,819 8,831 — — 6,819 8,831 15,650 (979) 12/31/2018 1998 3400 West Plano Parkway Plano, TX 1 — 4,543 15,964 321 — 4,543 16,285 20,828 (1,828) 12/31/2018 1994 3600 Wiseman Boulevard San Antonio, TX 1 — 3,493 6,662 3,309 — 3,493 9,971 13,464 (1,714) 12/31/2018 2004 701 Clay Road Waco, TX 1 — 2,030 8,708 14,479 — 2,060 23,157 25,217 (8,473) 12/23/1997 1997 1800 Novell Place Provo, UT 1 — 7,487 43,487 11,404 — 7,487 54,891 62,378 (5,233) 12/31/2018 2000 4885-4931 North 300 West Provo, UT 2 — 3,915 9,429 21 — 3,915 9,450 13,365 (1,113) 12/31/2018 2009 14660, 14672 & 14668 Lee Road Chantilly, VA 3 — 6,966 74,214 7,567 — 6,966 81,781 88,747 (12,503) 12/22/2016 1998; 2002; 2006 Enterchange at Meadowville Chester, VA 1 — 1,478 9,594 1,369 — 1,478 10,963 12,441 (2,367) 8/28/2013 1999 7987 Ashton Avenue Manassas, VA 1 — 1,562 8,253 1,069 — 1,562 9,322 10,884 (1,628) 1/3/2017 1989 Two Commercial Place Norfolk, VA 1 — 4,494 21,508 780 — 4,494 22,288 26,782 (2,350) 12/31/2018 1974 1759 Business Center Drive Reston, VA 1 — 4,033 28,517 1,562 — 4,033 30,079 34,112 (6,349) 5/28/2014 1987 1760 Business Center Drive Reston, VA 1 — 5,033 50,141 6,251 — 5,033 56,392 61,425 (11,959) 5/28/2014 1987 1775 Wiehle Avenue Reston, VA 1 — 4,138 26,120 4,552 — 4,138 30,672 34,810 (4,218) 10/2/2017 2001 9201 Forest Hill Avenue Richmond, VA 1 — 1,344 375 580 — 1,344 955 2,299 (165) 12/31/2018 1985 9960 Mayland Drive Richmond, VA 1 — 2,614 15,930 3,812 — 2,614 19,742 22,356 (4,402) 5/20/2014 1994 1751 Blue Hills Drive Roanoke, VA 1 — 2,689 7,761 — — 2,689 7,761 10,450 (861) 12/31/2018 2003 Atlantic Corporate Park Sterling, VA 2 — 5,752 29,316 2,885 — 5,752 32,201 37,953 (4,536) 10/2/2017 2008 Orbital Sciences Campus Sterling, VA 3 — 12,275 19,320 1,876 — 12,275 21,196 33,471 (2,429) 12/31/2018 2001 Initial Cost to Company Costs Capitalized Subsequent to Acquisition Cost amount carried at Close of Period Property Location Number of Properties Encumbrances (1) Land Buildings Impairments/ Land Buildings Total (2) Accumulated (3) Date(s) Original Sterling Park Business Center Sterling, VA 1 — 5,871 44,324 109 — 5,871 44,433 50,304 (5,832) 10/2/2017 2016 65 Bowdoin Street S. Burlington, VT 1 — 700 8,416 140 — 700 8,556 9,256 (2,742) 4/9/2010 2009 Stevens Center Richland, WA 2 — 3,970 17,035 4,737 — 4,042 21,700 25,742 (12,262) 3/31/1997 1995 Unison Elliott Bay-Lab Space Seattle, WA 2 — 17,316 34,281 49,266 — 17,316 83,547 100,863 (4,180) 12/31/2018 2000 Unison Elliott Bay-Office Space Seattle, WA 1 — 9,324 18,459 2,122 — 9,324 20,581 29,905 (2,251) 12/31/2018 2000 5353 Yellowstone Road Cheyenne, WY 1 — 1,915 8,217 2,085 — 1,950 10,267 12,217 (5,872) 3/31/1997 1995 157 $ 49,917 $ 820,568 $ 2,531,553 $ 588,478 $ (4,525) $ 821,238 $ 3,114,836 $ 3,936,074 $ (561,458) Properties Held for Sale Parham Place (4) Richmond, VA 3 — 913 1,099 572 — 913 1,671 2,584 (188) 6/9/2011 2006 3 — 913 1,099 572 — 913 1,671 2,584 (188) 160 $ 49,917 $ 821,481 $ 2,532,652 $ 589,050 $ (4,525) $ 822,151 $ 3,116,507 $ 3,938,658 $ (561,646) (1) Represents mortgage debt, net of the unamortized balance of the fair value adjustments and debt issuance costs totaling $83. (2) Excludes the value of real estate intangibles. Aggregate cost for federal income tax purposes is approximately $7,360,476. (3) Depreciation on building and improvements is provided for periods ranging up to 40 years and on equipment up to seven years. (4) Properties were sold in January 2023. An analysis of the carrying amount of real estate properties and accumulated depreciation is as follows: Real Estate Properties Accumulated Depreciation Balance at December 31, 2019 $ 3,493,231 $ 387,656 Additions 122,116 83,828 Loss on asset impairment (2,954) — Disposals (31,193) (13,125) Cost basis adjustment (1) (3,968) (3,968) Reclassification of assets of properties held for sale (55,089) (2,477) Balance at December 31, 2020 3,522,143 451,914 Additions 584,805 92,266 Loss on asset impairment (58,696) — Disposals (72,137) (8,675) Cost basis adjustment (1) (37,239) (37,239) Reclassification of assets of properties held for sale (27,790) (2,354) Balance at December 31, 2021 3,911,086 495,912 Additions 222,951 96,966 Loss on asset impairment (17,303) — Disposals (173,841) (26,997) Cost basis adjustment (1) (4,235) (4,235) Reclassification of assets of properties held for sale (2,584) (188) Balance at December 31, 2022 $ 3,936,074 $ 561,458 (1) Represents the reclassification between accumulated depreciation and building made to certain properties reclassified as assets of properties held for sale at fair value less costs to sell in accordance with GAAP.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
Summary of Significant Accounting Policies (Policies)	Dec. 31, 2022
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation. These consolidated financial statements include the accounts of us and our subsidiaries, all of which are wholly owned directly or indirectly by us. All intercompany transactions and balances with or among our consolidated subsidiaries have been eliminated.
Real Estate Properties	Real Estate Properties. We record our properties at cost and provide depreciation on real estate investments on a straight line basis over estimated useful lives generally ranging from 7 to 40 years. In some circumstances, we engage independent real estate appraisal firms to provide market information and evaluations which are relevant to our purchase price allocations and determinations of useful lives; however, we are ultimately responsible for the purchase price allocations and determinations of useful lives. We allocate the purchase prices of our properties to land, buildings and improvements based on determinations of the relative fair values of these assets assuming the properties are vacant. We determine the fair value of each property using methods similar to those used by independent appraisers, which may involve estimated cash flows that are based on a number of factors, including capitalization rates and discount rates, among others. We allocate a portion of the purchase price of our properties to above market and below market leases based on the present value (using an interest rate which reflects the risks associated with acquired in place leases at the time each property was acquired by us) of the difference, if any, between (i) the contractual amounts to be paid pursuant to the acquired in place leases and (ii) our estimates of fair market lease rates for the corresponding leases, measured over a period equal to the terms of the respective leases. We allocate a portion of the purchase price to acquired in place leases and tenant relationships based upon market estimates to lease up the property based on the leases in place at the time of purchase. We allocate this aggregate value between acquired in place lease values and tenant relationships based on our evaluation of the specific characteristics of each tenant’s lease. However, we have not separated the value of tenant relationships from the value of acquired in place leases because such value and related amortization expense is immaterial to the accompanying consolidated financial statements. In making these allocations, we consider factors such as estimated carrying costs during the expected lease up periods, including real estate taxes, insurance and other operating income and expenses and costs, such as leasing commissions, legal and other related expenses, to execute similar leases in current market conditions at the time a property was acquired by us. If the value of tenant relationships becomes material in the future, we may separately allocate those amounts and amortize the allocated amounts over the estimated life of the relationships. For transactions that qualify as business combinations, we allocate the excess, if any, of the consideration over the fair value of the assets acquired to goodwill. We amortize capitalized above market lease values (included in acquired real estate leases, net in our consolidated balance sheets) and below market lease values (presented as assumed real estate lease obligations, net in our consolidated balance sheets) as a reduction or increase, respectively, to rental income over the terms of the associated leases. Such amortization resulted in net decreases to rental income of $975, $2,288 and $5,440 during the years ended December 31, 2022, 2021 and 2020, respectively. We amortize the value of acquired in place leases (included in acquired real estate leases, net in our consolidated balance sheets), exclusive of the value of above market and below market acquired in place leases, over the terms of the associated leases. Such amortization, which is included in depreciation and amortization expense, amounted to $118,728, $142,538 and $161,752 during the years ended December 31, 2022, 2021 and 2020, respectively. If a lease is terminated prior to its stated expiration, we write off the unamortized amounts relating to that lease.
Cash and Cash Equivalents	Cash and Cash Equivalents. We consider highly liquid investments with original maturities of three months or less at the date of purchase to be cash equivalents.
Restricted Cash	Restricted Cash. Restricted cash consists of amounts escrowed for future real estate taxes, insurance, leasing costs, capital expenditures and debt service, as required by certain of our mortgage debts.
Deferred Leasing Costs	Deferred Leasing Costs. Deferred leasing costs include brokerage costs and inducements associated with our entering leases. We amortize deferred leasing costs, which are included in depreciation and amortization expense, and inducements, which are included as a reduction to rental income, on a straight line basis over the terms of the respective leases. Legal costs associated with the execution of our leases are expensed as incurred and included in general and administrative expenses in our consolidated statements of comprehensive income (loss).
Debt Issuance Costs	Debt Issuance Costs. Costs related to the issuance or assumption of debt are capitalized and amortized to interest expense over the terms of the respective loans. Debt issuance costs, net of accumulated amortization, for our revolving credit facility are included in other assets in our consolidated balance sheets. As of December 31, 2022 and 2021, debt issuance costs for our revolving credit facility were $4,593 and $4,125, respectively, and accumulated amortization of debt issuance costs for our revolving credit facility were $4,072 and $3,079, respectively. Debt issuance costs, net of accumulated amortization, for our senior unsecured notes and mortgage notes payable are presented as a direct deduction from the associated debt liability in our consolidated balance sheets.
Equity Method Investments	Equity Method Investments. We have noncontrolling ownership interests of 51% and 50% in two unconsolidated joint ventures that own three properties. The properties owned by these joint ventures are encumbered by an aggregate of $82,000 of mortgage indebtedness. We do not control the activities that are most significant to these joint ventures and, as a result, we account for our investments in these joint ventures under the equity method of accounting. See Note 4 for more information regarding our unconsolidated joint ventures.
Revenue Recognition	Revenue Recognition. We are a lessor of commercial office properties. Our leases provide our tenants with the contractual right to use and economically benefit from all of the physical space specified in the leases; therefore, we have determined to evaluate our leases as lease arrangements. Our leases provide for base rent payments and in addition may include variable payments. Rental income from operating leases, including any payments derived by index or market-based indices, is recognized on a straight line basis over the lease term when we have determined that the collectability of substantially all of the lease payments is probable. Some of our leases have options to extend or terminate the lease exercisable at the option of our tenants, which are considered when determining the lease term. Allowances for bad debts are recognized as a direct reduction of rental income. Certain of our leases contain non-lease components, such as property level operating expenses and capital expenditures reimbursed by our tenants as well as other required lease payments. We have made the policy election to not separate the lease and non-lease components because (i) the lease components are operating leases and (ii) the timing and pattern of recognition of the non-lease components are the same as those of the lease components. We apply Accounting Standards Codification 842, Leases , to the combined component. Income derived by our leases is recorded in rental income in our consolidated statements of comprehensive income (loss). Certain tenants are obligated to pay directly their obligations under their leases for insurance, real estate taxes and certain other expenses. These obligations, which have been assumed by the tenants under the terms of their respective leases, are not reflected in our consolidated financial statements. To the extent any tenant responsible for any such obligations under the applicable lease defaults on such lease or if it is deemed probable that the tenant will fail to pay for such obligations, we would record a liability for such obligations. See Note 5 for more information regarding our leases.
Income Taxes	Income Taxes. We have elected to be taxed as a REIT under the United States Internal Revenue Code of 1986, as amended, and, accordingly, we generally will not be subject to federal income taxes provided we distribute our taxable income and meet certain other requirements to qualify for taxation as a REIT. We are, however, subject to certain state and local taxes.
Cumulative Other Comprehensive Income (Loss)	Cumulative Other Comprehensive Income (Loss). Cumulative other comprehensive income (loss) represents our share of the cumulative comprehensive income and losses of our former equity method investees.
Per Common Share Amounts	Per Common Share Amounts. We calculate basic earnings per common share using the two class method. We calculate diluted earnings per share using the more dilutive of the two class method or the treasury stock method. Unvested share awards and other potentially dilutive common shares, together with the related impact on earnings, are considered when calculating diluted earnings per share.
Use of Estimates	Use of Estimates. Preparation of these financial statements in conformity with GAAP requires us to make estimates and assumptions that may affect the amounts reported in these consolidated financial statements and related notes. The actual results could differ from these estimates. Significant estimates in the consolidated financial statements include purchase price allocations, useful lives of fixed assets and assessment of impairment of real estate and the related intangibles.
Segment Reporting	Segment Reporting. We operate in one business segment: direct ownership of real estate properties.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
Summary of Significant Accounting Policies (Tables)	Dec. 31, 2022
Accounting Policies [Abstract]
Schedule of Real Estate Properties	As of December 31, 2022 and 2021, our acquired real estate leases and assumed real estate lease obligations, excluding properties classified as held for sale, were as follows: December 31, 2022 2021 Acquired real estate leases: Capitalized above market lease values $ 15,792 $ 29,925 Less: accumulated amortization (9,672) (17,945) Capitalized above market lease values, net 6,120 11,980 Lease origination value 728,773 885,250 Less: accumulated amortization (365,560) (391,601) Lease origination value, net 363,213 493,649 Acquired real estate leases, net $ 369,333 $ 505,629 Assumed real estate lease obligations: Capitalized below market lease values $ 27,033 $ 29,488 Less: accumulated amortization (12,876) (12,454) Assumed real estate lease obligations, net $ 14,157 $ 17,034

Per Common Share Amounts (Table

Per Common Share Amounts (Tables)	12 Months Ended
Per Common Share Amounts (Tables)	Dec. 31, 2022
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	The calculation of basic and diluted earnings per share is as follows (amounts in thousands, except per share amounts): Year Ended December 31, 2022 2021 2020 Numerators: Net income (loss) $ (6,109) $ (8,180) $ 6,678 Income attributable to unvested participating securities (427) — — Net income (loss) used in calculating earnings per share $ (6,536) $ (8,180) $ 6,678 Denominators: Weighted average common shares outstanding - basic and diluted (1) 48,278 48,195 48,124 Net income (loss) per common share - basic and diluted $ (0.14) $ (0.17) $ 0.14 (1) For the years ended December 31, 2022, 2021 and 2020, there were no dilutive common shares. In addition, for the years ended December 31, 2021 and 2020, 34 and 14 unvested common shares, respectively, were not included in the calculation of diluted earnings per share because to do so would have been antidilutive.

Real Estate Properties (Tables)

Real Estate Properties (Tables)	12 Months Ended
Real Estate Properties (Tables)	Dec. 31, 2022
Real Estate [Abstract]
Schedule of Business Acquisitions, by Acquisition	We allocated the purchase prices of these acquisitions based on the relative estimated fair values of the acquired assets and assumed liabilities as follows: Acquisition Date Location Number of Properties Rentable Square Feet Purchase Price Land Buildings and Improvements Acquired Real Estate Leases Assumed Real Estate Lease Obligations June 2021 Chicago, IL (1) 1 531,000 $ 368,331 $ 42,935 $ 258,348 $ 76,136 $ (9,088) June 2021 Atlanta, GA 1 346,000 180,602 13,040 135,459 32,103 — August 2021 Boston, MA 1 49,000 27,545 16,103 10,217 1,225 — 3 926,000 $ 576,478 $ 72,078 $ 404,024 $ 109,464 $ (9,088) (1) Purchase price includes an adjustment of $13,031 t o record an estimated real estate tax liability as of the acquisition date. Acquisition Date Location Number of Properties Rentable Square Feet Purchase Price Land Buildings and Improvements Acquired Real Estate Leases February 2020 Boston, MA 1 13,000 $ 11,864 $ 2,618 $ 9,246 $ — December 2020 Fort Mill, SC 1 150,000 35,351 5,031 22,526 7,794 2 163,000 $ 47,215 $ 7,649 $ 31,772 $ 7,794
Schedule of Disposal Groups	Date of Sale Number of Properties Location Rentable Square Feet Gross Sales Price (1) Gain (Loss) on Sale of Real Estate Loss on Impairment of Real Estate January 2022 1 Rockville, MD (2) 129,000 $ 6,750 $ (72) $ — February 2022 2 Chesapeake, VA (2) 172,000 18,945 2,296 — March 2022 1 Milwaukee, WI (2) 29,000 3,775 (75) — May 2022 1 Holtsville, NY 264,000 28,500 1,900 — June 2022 1 Fairfax, VA 184,000 19,750 (13,537) — July 2022 1 Houston, TX 206,000 9,800 (135) 15,278 August 2022 3 Birmingham, AL 448,000 16,050 (265) 3,709 August 2022 1 Erlanger, KY 86,000 2,600 135 2,184 September 2022 2 Chesapeake, VA 214,000 24,000 62 649 September 2022 2 Everett, WA 112,000 31,500 11,959 — September 2022 1 Salem, OR 233,000 34,250 5,369 — November 2022 1 Kapolei, HI (3) 109,000 4,000 2,504 — November 2022 1 Englewood, CO 140,000 11,100 860 — 18 2,326,000 $ 211,020 $ 11,001 $ 21,820 (1) Gross sales price is the gross contract price, excluding closing costs. (2) Properties were classified as held for sale as of December 31, 2021. (3) Property is a leasable land parcel. Date of Sale Number of Properties Location Rentable Square Feet Gross Sales Price (1) Gain (Loss) on Sale of Real Estate Loss on Impairment of Real Estate January 2021 — Kansas City, MO (2) (3) 10,000 $ 845 $ (63) $ — January 2021 1 Richmond, VA (2) 311,000 130,000 54,181 — April 2021 1 Huntsville, AL 1,371,000 39,000 — 5,383 July 2021 1 Fresno, CA 532,000 6,000 — 33,902 July 2021 1 Liverpool, NY 38,000 650 31 — August 2021 1 Memphis, TN 205,000 15,270 287 — September 2021 1 Stoneham, MA 98,000 6,650 (282) 5,911 October 2021 — Sterling, VA (4) — 28,500 24,200 — 6 2,565,000 $ 226,915 $ 78,354 $ 45,196 (1) Gross sales price is the gross contract price, excluding closing costs. (2) Properties were classified as held for sale as of December 31, 2020. (3) Consists of a warehouse facility. (4) Consists of two vacant land parcels. Date of Sale Number of Properties Location Rentable Square Feet Gross Sales Price (1) Gain (Loss) on Sale of Real Estate Loss on Impairment of Real Estate January 2020 2 Stafford, VA 65,000 $ 14,063 $ 4,771 $ — January 2020 1 Windsor, CT 97,000 7,000 314 — February 2020 1 Lincolnshire, IL 223,000 12,000 1,179 — March 2020 1 Trenton, NJ 267,000 30,100 (179) — March 2020 1 Fairfax, VA 83,000 22,200 4,754 — October 2020 4 Fairfax, VA 171,000 25,100 16 2,954 10 906,000 $ 110,463 $ 10,855 $ 2,954 (1) Gross sales price is the gross contract price, excluding closing costs.
Schedule of Joint Ventures	As of December 31, 2022 and 2021, our investments in unconsolidated joint ventures consisted of the following: OPI Ownership OPI Carrying Value of Investments at December 31, Number of Properties Location Rentable Square Feet Joint Venture 2022 2021 Prosperity Metro Plaza 51% $ 19,237 $ 20,672 2 Fairfax, VA 329,000 1750 H Street, NW 50% 15,892 14,166 1 Washington, D.C. 115,000 Total $ 35,129 $ 34,838 3 444,000 The following table provides a summary of the mortgage debt of our two unconsolidated joint ventures: Joint Venture Interest Rate (1) Maturity Date Principal Balance at December 31, 2022 and 2021 (2) Prosperity Metro Plaza 4.09% 12/1/2029 $ 50,000 1750 H Street, NW 3.69% 8/1/2024 32,000 Weighted Average/Total 3.93% $ 82,000 (1) Includes the effect of mark to market purchase accounting. (2) Reflects the entire balance of the debt secured by the properties and is not adjusted to reflect the interests in the joint ventures we do not own. None of the debt is recourse to us.

Leases (Tables)

Leases (Tables)	12 Months Ended
Leases (Tables)	Dec. 31, 2022
Leases [Abstract]
Schedule of Future Contractual Lease Payments to be Received	The following operating lease maturity analysis presents the future contractual lease payments to be received by us through 2053 as of December 31, 2022: Year Amount 2023 $ 393,318 2024 358,254 2025 313,267 2026 279,820 2027 248,976 Thereafter 1,393,682 Total $ 2,987,317

Indebtedness (Tables)

Indebtedness (Tables)	12 Months Ended
Indebtedness (Tables)	Dec. 31, 2022
Debt Disclosure [Abstract]
Schedule of Long-Term Debt Instruments	At December 31, 2022 and 2021, our outstanding indebtedness consisted of the following: December 31, 2022 2021 Revolving credit facility, due in 2023 $ 195,000 $ — Senior unsecured notes, 4.00% interest rate, due in 2022 (1) — 300,000 Senior unsecured notes, 4.25% interest rate, due in 2024 350,000 350,000 Senior unsecured notes, 4.50% interest rate, due in 2025 650,000 650,000 Senior unsecured notes, 2.650% interest rate, due in 2026 300,000 300,000 Senior unsecured notes, 2.400% interest rate, due in 2027 350,000 350,000 Senior unsecured notes, 3.450% interest rate, due in 2031 400,000 400,000 Senior unsecured notes, 6.375% interest rate, due in 2050 162,000 162,000 Mortgage note payable, 4.220% interest rate, due in 2022 (2) — 25,055 Mortgage note payable, 3.700% interest rate, due in 2023 50,000 50,000 Mortgage note payable, 4.800% interest rate, due in 2023 (3) — 23,246 2,457,000 2,610,301 Unamortized debt premiums, discounts and issuance costs (24,208) (32,351) $ 2,432,792 $ 2,577,950 (1) These senior notes were redeemed in June 2022. (2) This mortgage note was prepaid, at par plus accrued interest, in April 2022. (3) This mortgage note was prepaid, at a discounted amount of $22,176 plus accrued interest, in October 2022.
Schedule of Required Principal Payments	The required principal payments due during the next five years and thereafter under all our outstanding consolidated debt as of December 31, 2022 were as follows: Year Principal Payment 2023 $ 245,000 2024 350,000 2025 650,000 2026 300,000 2027 350,000 Thereafter 562,000 Total $ 2,457,000 (1) (1) Total consolidated debt outstanding as of December 31, 2022, net of unamortized premiums, discounts and issuance costs totaling $24,208, was $2,432,792.

Fair Value of Assets and Liab_2

Fair Value of Assets and Liabilities (Tables)	12 Months Ended
Fair Value of Assets and Liabilities (Tables)	Dec. 31, 2022
Fair Value Disclosures [Abstract]
Schedule of Fair Value and Carrying Value of Financial Instruments	At December 31, 2022 and 2021, the fair values of our financial instruments approximated their carrying values in our consolidated financial statements, due to their short term nature or floating interest rates, except as follows: As of December 31, 2022 As of December 31, 2021 Financial Instrument Carrying Value (1) Fair Value Carrying Value (1) Fair Value Senior unsecured notes, 4.00% interest rate, due in 2022 (2) $ — $ — $ 299,500 $ 304,148 Senior unsecured notes, 4.25% interest rate, due in 2024 346,863 331,601 344,581 365,449 Senior unsecured notes, 4.50% interest rate, due in 2025 642,818 589,388 639,370 687,749 Senior unsecured notes, 2.650% interest rate, due in 2026 297,839 232,770 297,213 298,502 Senior unsecured notes, 2.400% interest rate, due in 2027 347,466 256,606 346,845 339,764 Senior unsecured notes, 3.450% interest rate, due in 2031 396,178 268,004 395,744 388,458 Senior unsecured notes, 6.375% interest rate, due in 2050 156,711 113,075 156,519 177,098 Mortgage notes payable (3) 49,917 49,099 98,178 100,294 Total $ 2,237,792 $ 1,840,543 $ 2,577,950 $ 2,661,462 (1) Includes unamortized debt premiums, discounts and issuance costs totaling $24,208 and $32,351 as of December 31, 2022 and 2021, respectively. (2) These senior notes were redeemed in June 2022. (3) Balance as of December 31, 2021 includes a mortgage note secured by one property with an outstanding principal amount of $25,055 that was prepaid, at par plus accrued interest, in April 2022 and a mortgage note secured by one property with an outstanding principal balance of $23,246 that was prepaid, at a discounted amount of $22,176 plus accrued interest, in October 2022.

Shareholders' Equity (Tables)

Shareholders' Equity (Tables)	12 Months Ended
Shareholders' Equity (Tables)	Dec. 31, 2022
Equity [Abstract]
Summary of Shares Granted And Vested Under The Terms of The Entity's 2009 Plan	A summary of shares awarded, forfeited, vested and unvested under the terms of the 2009 Plan for the years ended December 31, 2022, 2021 and 2020, is as follows: 2022 2021 2020 Number of Shares Weighted Average Grant Date Fair Value Number of Shares Weighted Average Grant Date Fair Value Number of Shares Weighted Average Grant Date Fair Value Unvested at beginning of year 182,224 $ 26.23 157,521 $ 29.26 106,680 $ 40.16 Awarded 172,700 $ 17.74 145,800 $ 26.28 136,600 $ 23.77 Forfeited (1,900) $ 25.97 (700) $ 25.97 (586) $ 43.75 Vested (121,723) $ 23.24 (120,397) $ 30.24 (85,173) $ 34.02 Unvested at end of year 231,301 $ 21.47 182,224 $ 26.23 157,521 $ 29.26
Schedule of Dividends	During the years ended December 31, 2022, 2021 and 2020, we paid distributions on our common shares as follows: Annual Per Share Distribution Total Distributions Characterization of Distributions Year Return of Capital Ordinary Income Qualified Dividend 2022 $ 2.20 $ 106,630 62.68% 37.32% —% 2021 $ 2.20 $ 106,368 —% 100.00% —% 2020 $ 2.20 $ 106,121 —% 100.00% —%

Organization (Details)

Organization (Details)	12 Months Ended
Organization (Details)	Dec. 31, 2022 ft² joint_venture property	Dec. 31, 2021 ft²	Dec. 31, 2020 ft²
Real Estate Properties [Line Items]
Number of properties (in properties) \| property	160
Rentable area of properties (in square feet)		926,000	163,000
Number of joint ventures \| joint_venture	2
Unconsolidated Joint Ventures
Real Estate Properties [Line Items]
Number of properties (in properties) \| property	3
Rentable area of properties (in square feet)	444,000
Number of joint ventures \| joint_venture	2
Joint Venture Property 1
Real Estate Properties [Line Items]
Percentage of ownership interest	51%
Joint Venture Property 2
Real Estate Properties [Line Items]
Percentage of ownership interest	50%
Continuing Operations
Real Estate Properties [Line Items]
Rentable area of properties (in square feet)	20,969,000

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Real Estate Properties, Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Real Estate [Line Items]
Net decreases to rental income from amortization of capitalized above market and below market leases	$ 975	$ 2,288	$ 5,440
Amortization of the value of leases	119,703	144,826	167,192
Projected future amortization of net intangible lease assets and liabilities, excluding those classified as discontinued operations
2023	90,999
2024	73,905
2025	53,792
2026	39,983
2027	31,313
Thereafter	65,184
Original Value Lease
Real Estate [Line Items]
Amortization of the value of leases	$ 118,728	$ 142,538	$ 161,752
Minimum \| Buildings and Improvements
Real Estate [Line Items]
Property, plant and equipment, useful life	7 years
Maximum \| Buildings and Improvements
Real Estate [Line Items]
Property, plant and equipment, useful life	40 years
Weighted Average
Real Estate [Line Items]
Below market, acquired lease amortization period	10 years 10 months 24 days
Weighted Average \| Above Market Lease
Real Estate [Line Items]
Acquired lease amortization period	3 years 9 months 18 days
Weighted Average \| Original Value Lease
Real Estate [Line Items]
Acquired lease amortization period	6 years 4 months 24 days

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Schedule of Real Estate Assets and Obligations (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Real Estate [Line Items]
Acquired real estate leases, net	$ 369,333	$ 505,629
Capitalized below market lease values	27,033	29,488
Less: accumulated amortization	(12,876)	(12,454)
Assumed real estate lease obligations, net	14,157	17,034
Above Market Lease
Real Estate [Line Items]
Real estate leases	15,792	29,925
Less: accumulated amortization	(9,672)	(17,945)
Acquired real estate leases, net	6,120	11,980
Original Value Lease
Real Estate [Line Items]
Real estate leases	728,773	885,250
Less: accumulated amortization	(365,560)	(391,601)
Acquired real estate leases, net	$ 363,213	$ 493,649

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Deferred Leasing and Debt Issuance Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Amortization of deferred leasing costs	$ 6,869	$ 6,691	$ 5,985
Deferred sales inducement cost, amortization expense	1,124	1,187	$ 902
Deferred leasing costs, gross	94,680	74,469
Accumulated amortization of deferred leasing costs	21,582	20,586
Future amortization of deferred leasing costs, excluding those classified as discontinued operations
2023	9,938
2024	8,837
2025	7,838
2026	7,260
2027	6,424
Thereafter	32,801
Deferred financing fees, net	13,589	16,120
Future amortization of deferred financing fees
2023	2,676
2024	2,155
2025	1,669
2026	1,335
2027	595
Thereafter	5,680
Unsecured Revolving Credit Facility
Future amortization of deferred leasing costs, excluding those classified as discontinued operations
Deferred financing fees, gross	4,593	4,125
Accumulated amortization of deferred financing fees	$ 4,072	$ 3,079

Summary of Significant Accoun_7

Summary of Significant Accounting Policies - Additional Information (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($) property joint_venture segment	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Jun. 05, 2015 USD ($) shares
Schedule of Equity Method Investments [Line Items]
Number of joint ventures \| joint_venture	2
Number of properties (in properties) \| property	160
Unamortized discount (premium), net	$ 14,145
Number of business segments \| segment	1
Joint Venture Property 1
Schedule of Equity Method Investments [Line Items]
Percentage of ownership interest	51%
Joint Venture Property 2
Schedule of Equity Method Investments [Line Items]
Percentage of ownership interest	50%
RMR Inc
Schedule of Equity Method Investments [Line Items]
Equity securities, FV-NI (in shares) \| shares				1,541,201
Equity securities, FV-NI, cost				$ 17,462
Unconsolidated Joint Ventures
Schedule of Equity Method Investments [Line Items]
Number of joint ventures \| joint_venture	2
Number of properties (in properties) \| property	3
Unconsolidated Joint Ventures \| Joint Venture Property 1
Schedule of Equity Method Investments [Line Items]
Percentage of ownership interest	51%
Unconsolidated Joint Ventures \| Joint Venture Property 2
Schedule of Equity Method Investments [Line Items]
Percentage of ownership interest	50%
Unconsolidated Joint Ventures
Schedule of Equity Method Investments [Line Items]
Number of joint ventures \| joint_venture	2
Number of properties (in properties) \| property	3
Unconsolidated Joint Ventures \| Mortgage Note Payable
Schedule of Equity Method Investments [Line Items]
Principal balance	$ 82,000	$ 82,000
RMR Inc
Schedule of Equity Method Investments [Line Items]
Equity securities, FV-NI				$ 39,833
Amortization of liability	1,087	$ 1,087	$ 1,087
Amortization of liability, year one	1,087
Amortization of liability, year two	1,087
Amortization of liability, year three	1,087
Amortization of liability, year four	1,087
Amortization of liability, year five	1,087
Amortization of liability, thereafter	$ 8,710

Per Common Share Amounts - Inco

Per Common Share Amounts - Income (Loss) Per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Numerators:
Net income (loss)	$ (6,109)	$ (8,180)	$ 6,678
Income attributable to unvested participating securities	(427)	0	0
Net income (loss) used in calculating earnings per share	$ (6,536)	$ (8,180)	$ 6,678
Denominators:
Weighted average common shares for basic earnings per share (in shares)	48,278	48,195	48,124
Weighted average common shares outstanding, diluted (in shares)	48,278	48,195	48,124
Net income (loss) per common share - basic (in dollars per share)	$ (0.14)	$ (0.17)	$ 0.14
Net income (loss) per common share - diluted (in dollars per share)	$ (0.14)	$ (0.17)	$ 0.14
Antidilutive securities (in shares)		34	14

Real Estate Properties - Real E

Real Estate Properties - Real Estate Properties Narrative (Details) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2021 USD ($) property	Dec. 31, 2022 USD ($) ft² joint_venture property lease	Dec. 31, 2021 USD ($) ft² property parcel_of_land	Dec. 31, 2020 USD ($) ft² property
Real Estate Properties [Line Items]
Number of properties (in properties) \| property		160
Area of properties (in square feet) \| ft²			926,000	163,000
Real estate aggregate undepreciated carrying value		$ 3,936,074	$ 3,911,086
Number of joint ventures \| joint_venture		2
Number of leases entered \| lease		75
Rentable square feet (in sqft) \| ft²		2,562,000
Weighted average lease term		9 years 3 months 18 days
Expenditures committed on leases		$ 173,419
Operating leases committed expenditures on leases executed in period committed but unspent tenant related obligations		156,693
Loss on impairment of real estate		$ 21,820	$ 62,420	$ 2,954
Unconsolidated Joint Ventures
Real Estate Properties [Line Items]
Number of properties (in properties) \| property		3
Area of properties (in square feet) \| ft²		444,000
Number of joint ventures \| joint_venture		2
Unconsolidated Joint Ventures \| Mortgage Note Payable
Real Estate Properties [Line Items]
Interest rate (as a percent)		3.93%
Joint Venture Property 1
Real Estate Properties [Line Items]
Percentage of ownership interest		51%
Joint Venture Property 2
Real Estate Properties [Line Items]
Percentage of ownership interest		50%
Disposal Group, Disposed of by Sale
Real Estate Properties [Line Items]
Number of properties (in properties) \| property		18	6	10
Area of properties (in square feet) \| ft²		2,326,000	2,565,000	906,000
Gross Sales Price, Excluding Closing Costs		$ 211,020	$ 226,915	$ 110,463
Rentable Square Feet \| ft²			2,565,000
Loss on impairment of real estate		$ 21,820	$ 45,196	$ 2,954
Number of real estate properties sold (in properties) \| property			6	10
Disposal Group, Disposed of by Sale \| Mortgage notes payable, 5.9% interest rate, due in 2021 \| Mortgage Note Payable
Real Estate Properties [Line Items]
Extinguishment of debt, amount				$ 13,095
Interest rate (as a percent)				5.90%
Disposal Group, Disposed of by Sale \| Sterling, VA
Real Estate Properties [Line Items]
Number of properties (in properties) \| property			0
Area of properties (in square feet) \| ft²			0
Gross Sales Price, Excluding Closing Costs			$ 28,500
Number of land parcels \| parcel_of_land			2
Loss on impairment of real estate			$ 0
Disposal Group, Disposed of by Sale \| Brookhaven, GA
Real Estate Properties [Line Items]
Number of properties (in properties) \| property	3
Gross Sales Price, Excluding Closing Costs	$ 10,658
Loss on impairment of real estate			$ 425
Disposal Group, Held-for-sale, Not Discontinued Operations
Real Estate Properties [Line Items]
Number of properties (in properties) \| property			2
Loss on impairment of real estate			$ 6,991
Continuing Operations
Real Estate Properties [Line Items]
Area of properties (in square feet) \| ft²		20,969,000
Real estate aggregate undepreciated carrying value		$ 3,938,658
Continuing Operations \| Disposal Group, Held-for-sale, Not Discontinued Operations
Real Estate Properties [Line Items]
Carrying value		$ 2,584

Real Estate Properties - Acquis

Real Estate Properties - Acquisition Activities (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2021 USD ($) ft² property	Dec. 31, 2020 USD ($) ft² property
Business Acquisition [Line Items]
Number of properties acquired \| property	3	2
Rentable square feet (in square feet) \| ft²	926,000	163,000
Asset acquisition, consideration transferred	$ 576,478	$ 47,215
Purchase price adjustments	1,761
Assumed Real Estate Lease Obligations	(9,088)
Acquisition related costs	1,264	590
Adjustment for estimated tax liability	13,031
Land
Business Acquisition [Line Items]
Asset acquisition, consideration transferred	72,078	7,649
Buildings and Improvements
Business Acquisition [Line Items]
Asset acquisition, consideration transferred	404,024	31,772
Acquired Real Estate Leases
Business Acquisition [Line Items]
Asset acquisition, consideration transferred	$ 109,464	$ 7,794
Chicago, IL
Business Acquisition [Line Items]
Number of properties acquired \| property	1
Rentable square feet (in square feet) \| ft²	531,000
Asset acquisition, consideration transferred	$ 368,331
Assumed Real Estate Lease Obligations	(9,088)
Chicago, IL \| Land
Business Acquisition [Line Items]
Asset acquisition, consideration transferred	42,935
Chicago, IL \| Buildings and Improvements
Business Acquisition [Line Items]
Asset acquisition, consideration transferred	258,348
Chicago, IL \| Acquired Real Estate Leases
Business Acquisition [Line Items]
Asset acquisition, consideration transferred	$ 76,136
Atlanta, GA
Business Acquisition [Line Items]
Number of properties acquired \| property	1
Rentable square feet (in square feet) \| ft²	346,000
Asset acquisition, consideration transferred	$ 180,602
Assumed Real Estate Lease Obligations	0
Atlanta, GA \| Land
Business Acquisition [Line Items]
Asset acquisition, consideration transferred	13,040
Atlanta, GA \| Buildings and Improvements
Business Acquisition [Line Items]
Asset acquisition, consideration transferred	135,459
Atlanta, GA \| Acquired Real Estate Leases
Business Acquisition [Line Items]
Asset acquisition, consideration transferred	$ 32,103
Boston, MA
Business Acquisition [Line Items]
Number of properties acquired \| property	1	1
Rentable square feet (in square feet) \| ft²	49,000	13,000
Asset acquisition, consideration transferred	$ 27,545	$ 11,864
Assumed Real Estate Lease Obligations	0
Boston, MA \| Land
Business Acquisition [Line Items]
Asset acquisition, consideration transferred	16,103	2,618
Boston, MA \| Buildings and Improvements
Business Acquisition [Line Items]
Asset acquisition, consideration transferred	10,217	9,246
Boston, MA \| Acquired Real Estate Leases
Business Acquisition [Line Items]
Asset acquisition, consideration transferred	$ 1,225	$ 0
Fort Mill, SC
Business Acquisition [Line Items]
Number of properties acquired \| property		1
Rentable square feet (in square feet) \| ft²		150,000
Asset acquisition, consideration transferred		$ 35,351
Fort Mill, SC \| Land
Business Acquisition [Line Items]
Asset acquisition, consideration transferred		5,031
Fort Mill, SC \| Buildings and Improvements
Business Acquisition [Line Items]
Asset acquisition, consideration transferred		22,526
Fort Mill, SC \| Acquired Real Estate Leases
Business Acquisition [Line Items]
Asset acquisition, consideration transferred		$ 7,794

Real Estate Properties - Dispos

Real Estate Properties - Disposition Activities (Details) $ in Thousands		12 Months Ended
	Feb. 14, 2023 USD ($) ft² property	Dec. 31, 2022 USD ($) ft² property	Dec. 31, 2021 USD ($) ft² property parcel_of_land	Dec. 31, 2020 USD ($) ft² property
Real Estate Properties [Line Items]
Number of properties (in properties) \| property		160
Rentable square feet (in square feet) \| ft²			926,000	163,000
Gain (Loss) on Sale of Real Estate		$ 11,001	$ 78,354	$ 10,855
Loss on impairment of real estate		$ 21,820	$ 62,420	$ 2,954
Disposal Group, Disposed of by Sale
Real Estate Properties [Line Items]
Number of properties (in properties) \| property		18	6	10
Rentable square feet (in square feet) \| ft²		2,326,000	2,565,000	906,000
Gross Sales Price, Excluding Closing Costs		$ 211,020	$ 226,915	$ 110,463
Gain (Loss) on Sale of Real Estate		11,001	78,354	10,855
Loss on impairment of real estate		$ 21,820	$ 45,196	$ 2,954
Disposal Group, Disposed of by Sale \| Subsequent Event
Real Estate Properties [Line Items]
Number of properties (in properties) \| property	2
Rentable square feet (in square feet) \| ft²	207,000
Gross Sales Price, Excluding Closing Costs	$ 7,600
Disposal Group, Held-for-sale, Not Discontinued Operations
Real Estate Properties [Line Items]
Number of properties (in properties) \| property			2
Loss on impairment of real estate			$ 6,991
Rockville, MD \| Disposal Group, Disposed of by Sale
Real Estate Properties [Line Items]
Number of properties (in properties) \| property		1
Rentable square feet (in square feet) \| ft²		129,000
Gross Sales Price, Excluding Closing Costs		$ 6,750
Gain (Loss) on Sale of Real Estate		$ (72)
Chesapeake, VA \| Disposal Group, Disposed of by Sale
Real Estate Properties [Line Items]
Number of properties (in properties) \| property		2
Rentable square feet (in square feet) \| ft²		172,000
Gross Sales Price, Excluding Closing Costs		$ 18,945
Gain (Loss) on Sale of Real Estate		$ 2,296
Milwaukee, WI \| Disposal Group, Disposed of by Sale
Real Estate Properties [Line Items]
Number of properties (in properties) \| property		1
Rentable square feet (in square feet) \| ft²		29,000
Gross Sales Price, Excluding Closing Costs		$ 3,775
Gain (Loss) on Sale of Real Estate		$ (75)
Holtsville, NY \| Disposal Group, Disposed of by Sale
Real Estate Properties [Line Items]
Number of properties (in properties) \| property		1
Rentable square feet (in square feet) \| ft²		264,000
Gross Sales Price, Excluding Closing Costs		$ 28,500
Gain (Loss) on Sale of Real Estate		$ 1,900
Fairfax, VA \| Disposal Group, Disposed of by Sale
Real Estate Properties [Line Items]
Number of properties (in properties) \| property		1		1
Rentable square feet (in square feet) \| ft²		184,000		83,000
Gross Sales Price, Excluding Closing Costs		$ 19,750		$ 22,200
Gain (Loss) on Sale of Real Estate		$ (13,537)		4,754
Loss on impairment of real estate				$ 0
Houston, TX \| Disposal Group, Disposed of by Sale
Real Estate Properties [Line Items]
Number of properties (in properties) \| property		1
Rentable square feet (in square feet) \| ft²		206,000
Gross Sales Price, Excluding Closing Costs		$ 9,800
Gain (Loss) on Sale of Real Estate		(135)
Loss on impairment of real estate		$ 15,278
Birmingham, AL \| Disposal Group, Disposed of by Sale
Real Estate Properties [Line Items]
Number of properties (in properties) \| property		3
Rentable square feet (in square feet) \| ft²		448,000
Gross Sales Price, Excluding Closing Costs		$ 16,050
Gain (Loss) on Sale of Real Estate		(265)
Loss on impairment of real estate		$ 3,709
Erlanger, KY \| Disposal Group, Disposed of by Sale
Real Estate Properties [Line Items]
Number of properties (in properties) \| property		1
Rentable square feet (in square feet) \| ft²		86,000
Gross Sales Price, Excluding Closing Costs		$ 2,600
Gain (Loss) on Sale of Real Estate		135
Loss on impairment of real estate		$ 2,184
Chesapeake, VA \| Disposal Group, Disposed of by Sale
Real Estate Properties [Line Items]
Number of properties (in properties) \| property		2
Rentable square feet (in square feet) \| ft²		214,000
Gross Sales Price, Excluding Closing Costs		$ 24,000
Gain (Loss) on Sale of Real Estate		62
Loss on impairment of real estate		$ 649
Everett, WA \| Disposal Group, Disposed of by Sale
Real Estate Properties [Line Items]
Number of properties (in properties) \| property		2
Rentable square feet (in square feet) \| ft²		112,000
Gross Sales Price, Excluding Closing Costs		$ 31,500
Gain (Loss) on Sale of Real Estate		$ 11,959
Salem, OR \| Disposal Group, Disposed of by Sale
Real Estate Properties [Line Items]
Number of properties (in properties) \| property		1
Rentable square feet (in square feet) \| ft²		233,000
Gross Sales Price, Excluding Closing Costs		$ 34,250
Gain (Loss) on Sale of Real Estate		$ 5,369
Kapolei, HI \| Disposal Group, Disposed of by Sale
Real Estate Properties [Line Items]
Number of properties (in properties) \| property		1
Rentable square feet (in square feet) \| ft²		109,000
Gross Sales Price, Excluding Closing Costs		$ 4,000
Gain (Loss) on Sale of Real Estate		$ 2,504
Eaglewood, CO \| Disposal Group, Disposed of by Sale
Real Estate Properties [Line Items]
Number of properties (in properties) \| property		1
Rentable square feet (in square feet) \| ft²		140,000
Gross Sales Price, Excluding Closing Costs		$ 11,100
Gain (Loss) on Sale of Real Estate		$ 860
Kansas City, MO \| Disposal Group, Disposed of by Sale
Real Estate Properties [Line Items]
Number of properties (in properties) \| property			0
Rentable square feet (in square feet) \| ft²			10,000
Gross Sales Price, Excluding Closing Costs			$ 845
Gain (Loss) on Sale of Real Estate			(63)
Loss on impairment of real estate			$ 0
Richmond, VA \| Disposal Group, Disposed of by Sale
Real Estate Properties [Line Items]
Number of properties (in properties) \| property		3	1
Rentable square feet (in square feet) \| ft²		89,000	311,000
Gross Sales Price, Excluding Closing Costs		$ 5,350	$ 130,000
Gain (Loss) on Sale of Real Estate			54,181
Loss on impairment of real estate			$ 0
Huntsville, AL \| Disposal Group, Disposed of by Sale
Real Estate Properties [Line Items]
Number of properties (in properties) \| property			1
Rentable square feet (in square feet) \| ft²			1,371,000
Gross Sales Price, Excluding Closing Costs			$ 39,000
Gain (Loss) on Sale of Real Estate			0
Loss on impairment of real estate			$ 5,383
Fresno, CA \| Disposal Group, Disposed of by Sale
Real Estate Properties [Line Items]
Number of properties (in properties) \| property			1
Rentable square feet (in square feet) \| ft²			532,000
Gross Sales Price, Excluding Closing Costs			$ 6,000
Gain (Loss) on Sale of Real Estate			0
Loss on impairment of real estate			$ 33,902
Liverpool, NY \| Disposal Group, Disposed of by Sale
Real Estate Properties [Line Items]
Number of properties (in properties) \| property			1
Rentable square feet (in square feet) \| ft²			38,000
Gross Sales Price, Excluding Closing Costs			$ 650
Gain (Loss) on Sale of Real Estate			31
Loss on impairment of real estate			$ 0
Memphis, TN \| Disposal Group, Disposed of by Sale
Real Estate Properties [Line Items]
Number of properties (in properties) \| property			1
Rentable square feet (in square feet) \| ft²			205,000
Gross Sales Price, Excluding Closing Costs			$ 15,270
Gain (Loss) on Sale of Real Estate			287
Loss on impairment of real estate			$ 0
Stoneham, MA \| Disposal Group, Disposed of by Sale
Real Estate Properties [Line Items]
Number of properties (in properties) \| property			1
Rentable square feet (in square feet) \| ft²			98,000
Gross Sales Price, Excluding Closing Costs			$ 6,650
Gain (Loss) on Sale of Real Estate			(282)
Loss on impairment of real estate			$ 5,911
Sterling, VA \| Disposal Group, Disposed of by Sale
Real Estate Properties [Line Items]
Number of properties (in properties) \| property			0
Rentable square feet (in square feet) \| ft²			0
Gross Sales Price, Excluding Closing Costs			$ 28,500
Gain (Loss) on Sale of Real Estate			24,200
Loss on impairment of real estate			$ 0
Number of land parcels \| parcel_of_land			2
Stafford, VA \| Disposal Group, Disposed of by Sale
Real Estate Properties [Line Items]
Number of properties (in properties) \| property				2
Rentable square feet (in square feet) \| ft²				65,000
Gross Sales Price, Excluding Closing Costs				$ 14,063
Gain (Loss) on Sale of Real Estate				4,771
Loss on impairment of real estate				$ 0
Windsor, CT \| Disposal Group, Disposed of by Sale
Real Estate Properties [Line Items]
Number of properties (in properties) \| property				1
Rentable square feet (in square feet) \| ft²				97,000
Gross Sales Price, Excluding Closing Costs				$ 7,000
Gain (Loss) on Sale of Real Estate				314
Loss on impairment of real estate				$ 0
Lincolnshire, IL \| Disposal Group, Disposed of by Sale
Real Estate Properties [Line Items]
Number of properties (in properties) \| property				1
Rentable square feet (in square feet) \| ft²				223,000
Gross Sales Price, Excluding Closing Costs				$ 12,000
Gain (Loss) on Sale of Real Estate				1,179
Loss on impairment of real estate				$ 0
Trenton, NJ \| Disposal Group, Disposed of by Sale
Real Estate Properties [Line Items]
Number of properties (in properties) \| property				1
Rentable square feet (in square feet) \| ft²				267,000
Gross Sales Price, Excluding Closing Costs				$ 30,100
Gain (Loss) on Sale of Real Estate				(179)
Loss on impairment of real estate				$ 0
Fairfax, VA \| Disposal Group, Disposed of by Sale
Real Estate Properties [Line Items]
Number of properties (in properties) \| property				4
Rentable square feet (in square feet) \| ft²				171,000
Gross Sales Price, Excluding Closing Costs				$ 25,100
Gain (Loss) on Sale of Real Estate				16
Loss on impairment of real estate				$ 2,954

Real Estate Properties - Uncons

Real Estate Properties - Unconsolidated Joint Ventures (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($) ft² joint_venture property	Dec. 31, 2021 USD ($) ft²	Dec. 31, 2020 ft²
Real Estate [Line Items]
Number of joint ventures \| joint_venture	2
Number of properties (in properties) \| property	160
Rentable square feet (in square feet) \| ft²		926,000	163,000
Unconsolidated Joint Ventures
Real Estate [Line Items]
Number of joint ventures \| joint_venture	2
Number of properties (in properties) \| property	3
OPI Carrying Value of Investments	$ 35,129	$ 34,838
Rentable square feet (in square feet) \| ft²	444,000
Equity method investment, difference between carrying amount and underlying equity	$ 6,489
Unconsolidated Joint Ventures \| Mortgage Note Payable
Real Estate [Line Items]
Interest rate (as a percent)	3.93%
Principal balance	$ 82,000	82,000
Unconsolidated Joint Ventures \| Prosperity Metro Plaza
Real Estate [Line Items]
Number of properties (in properties) \| property	2
OPI Ownership	51%
OPI Carrying Value of Investments	$ 19,237	20,672
Rentable square feet (in square feet) \| ft²	329,000
Unconsolidated Joint Ventures \| Prosperity Metro Plaza \| Mortgage Note Payable
Real Estate [Line Items]
Interest rate (as a percent)	4.09%
Principal balance	$ 50,000	50,000
Unconsolidated Joint Ventures \| 1750 H Street, NW
Real Estate [Line Items]
Number of properties (in properties) \| property	1
OPI Ownership	50%
OPI Carrying Value of Investments	$ 15,892	14,166
Rentable square feet (in square feet) \| ft²	115,000
Unconsolidated Joint Ventures \| 1750 H Street, NW \| Mortgage Note Payable
Real Estate [Line Items]
Interest rate (as a percent)	3.69%
Principal balance	$ 32,000	$ 32,000

Leases - Narrative (Details)

Leases - Narrative (Details) $ in Thousands	12 Months Ended
Leases - Narrative (Details) $ in Thousands	Dec. 31, 2022 USD ($) tenant	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Lessee, Lease, Description [Line Items]
Straight line rent adjustments	$ 10,830	$ 15,368	$ 16,079
Straight line rent receivables	86,305	82,978
Variable lease, income	83,103	85,107	75,851
Tenant reimbursement income	$ 78,388	81,295	71,385
Lease expense		$ 79	$ 1,749
Lessor, Operating Lease, Payment to be Received
Lessee, Lease, Description [Line Items]
Number of government tenants with the right to terminate their leases \| tenant	10
Lessor, Operating Lease, Payment to be Received \| Tenant with Exercisable Termination Rights \| Tenant Concentration
Lessee, Lease, Description [Line Items]
Concentration risk, percentage	1.50%
2023	1.30%
2024	2.40%
2025	5.60%
2026	1.60%
2027	1.60%
2028	5.50%
2029	2.10%
2030	1.60%
2031	0.30%
2035	3.50%
2037	0.40%
2040	1.70%
Lessor, Operating Lease, Payment to be Received \| Fourteen Government Tenants \| Tenant Concentration
Lessee, Lease, Description [Line Items]
Concentration risk, percentage	4.80%

Leases - Operating Lease Maturi

Leases - Operating Lease Maturity (Details) $ in Thousands	Dec. 31, 2022 USD ($)
Leases [Abstract]
2023	$ 393,318
2024	358,254
2025	313,267
2026	279,820
2027	248,976
Thereafter	1,393,682
Total	$ 2,987,317

Business and Property Managem_2

Business and Property Management Agreements with RMR (Details) - RMR LLC $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($) agreement employee	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Related Party Transaction [Line Items]
Number of employees \| employee	0
Number of agreements with RMR LLC to provide management services \| agreement	2
Net business management fees		$ 18,637	$ 17,358
Recognized amortization of the liability	$ 603	603	603
Management fees as percentage of gross collected rents	3%
Construction supervision fees as percentage of construction costs	5%
Reimbursement amounts	$ 24,371	24,766	24,919
Net Property Management and Construction Supervision Fees
Related Party Transaction [Line Items]
Net business management fees	17,376
Transaction amount	25,756	21,103	20,774
Reimbursement amounts	484	484	484
Net Property Management and Construction Supervision Fees \| Investment Building and Building Improvements
Related Party Transaction [Line Items]
Transaction amount	9,917	4,596	3,446
Net Property Management and Construction Supervision Fees \| Other Operating Income (Expense)
Related Party Transaction [Line Items]
Transaction amount	$ 15,839	$ 16,507	$ 17,328
Transition Services
Related Party Transaction [Line Items]
Duration of transition services	120 days
Amended And Restate Business Management Agreement
Related Party Transaction [Line Items]
Percentage applied on average historical cost of real estate investment properties acquired	0.50%
Base management fee payable as percentage of average historical cost of real estate investments	0.70%
Percentage of average closing stock price on stock exchange	0.70%
Management fee payable as percentage of average market capitalization exceeding specified amount	0.50%
Percentage for limitation and adjustments of incentive management fee payable	12%
Measurement period for incentive management fee	3 years
Average closing price of our common shares, consecutive trading days	10 days
Highest average closing price of our common shares, final consecutive trading days	30 days
Percentage for limitation and adjustments of incentive management fee payable, minimum total return per share percentage change	5%
Percentage of base business management fee payable in common shares	1.50%
Amended And Restate Business Management Agreement \| Up C Transaction
Related Party Transaction [Line Items]
Written notice for convenience	60 days
Window of written notice after calendar year	60 days
Window for written notice after change of control	12 months
Remaining termination fee term	10 years
Amended And Restate Business Management Agreement \| Maximum
Related Party Transaction [Line Items]
Threshold amount of real estate investments	$ 250,000
Threshold amount of average market capitalization	$ 250,000
Percentage for limitation and adjustments of incentive management fee payable, total return per share percentage, reduction	5%
Amended And Restate Business Management Agreement \| Maximum \| Up C Transaction
Related Party Transaction [Line Items]
Termination fee term	20 years
Amended And Restate Business Management Agreement \| Minimum
Related Party Transaction [Line Items]
Threshold amount of real estate investments	$ 250,000
Base management fee payable average market capitalization	$ 250,000
Percentage for limitation and adjustments of incentive management fee payable, total return per share percentage, reduction	2%
Amended And Restate Business Management Agreement \| Minimum \| Up C Transaction
Related Party Transaction [Line Items]
Termination fee term	19 years

Related Person Transactions (De

Related Person Transactions (Details) $ in Thousands	1 Months Ended			12 Months Ended			22 Months Ended
Related Person Transactions (Details) $ in Thousands	Dec. 31, 2021 USD ($) ft²	Jun. 30, 2021 USD ($) ft² renewal_option	Jun. 30, 2020 USD ($)	Dec. 31, 2022 USD ($) agreement	Dec. 31, 2021 USD ($) ft²	Dec. 31, 2020 USD ($) ft²	Mar. 31, 2023 USD ($)
Related Party Transaction [Line Items]
Rentable square feet (in square feet) \| ft²	926,000				926,000	163,000
Officers and Other Employees \| Common Shares \| 2009 Award Plan
Related Party Transaction [Line Items]
Award vesting period				4 years
Share-based Payment Arrangement, Tranche 1 \| Officers and Other Employees \| Common Shares \| 2009 Award Plan
Related Party Transaction [Line Items]
Award vesting rights, percentage				20%
Share-based Payment Arrangement, Tranche 2 \| Officers and Other Employees \| Common Shares \| 2009 Award Plan
Related Party Transaction [Line Items]
Award vesting rights, percentage				20%
Share-based Payment Arrangement, Tranche 3 \| Officers and Other Employees \| Common Shares \| 2009 Award Plan
Related Party Transaction [Line Items]
Award vesting rights, percentage				20%
Share-based Compensation Award, Tranche 4 \| Officers and Other Employees \| Common Shares \| 2009 Award Plan
Related Party Transaction [Line Items]
Award vesting rights, percentage				20%
Share-based Compensation Award, Tranche 5 \| Officers and Other Employees \| Common Shares \| 2009 Award Plan
Related Party Transaction [Line Items]
Award vesting rights, percentage				20%
RMR LLC
Related Party Transaction [Line Items]
Number of agreements with RMR LLC to provide management services \| agreement				2
Rental income earned				$ 1,126	$ 1,138	$ 1,120
Sonesta International Hotels Corporation
Related Party Transaction [Line Items]
Lease term		30 years
Rentable square feet (in square feet) \| ft²		230,000
Percentage upon completion of redevelopment		54%
Number of renewal options \| renewal_option		2
Renewal term		10 years
Annual base rent		$ 6,436
Deferred payment plan period		18 months
Annual percentage increase		10%
Annual base rent increase		5 years
Sonesta International Hotels Corporation \| Forecast
Related Party Transaction [Line Items]
Purchase price							$ 66,000
Affiliates Insurance Company
Related Party Transaction [Line Items]
Distribution of earnings from Affiliates Insurance Company	$ 11		$ 287

Concentration (Details)

Concentration (Details) - property	12 Months Ended
Concentration (Details) - property	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Concentration Risk [Line Items]
Number of properties (in properties)	160
Number of states in which acquired properties located	30
Annualized Rental Income, Excluding Properties Classified as Discontinued Operations \| Tenant Concentration \| U S Government, State Governments, and Other Governments
Concentration Risk [Line Items]
Concentration risk, percentage	28.50%	28.90%	35.30%
Annualized Rental Income, Excluding Properties Classified as Discontinued Operations \| Tenant Concentration \| U.S. Government
Concentration Risk [Line Items]
Concentration risk, percentage	19.70%	19.50%	25.20%
Annualized Rental Income, Excluding Properties Classified as Discontinued Operations \| Geographic Concentration Risk \| California
Concentration Risk [Line Items]
Concentration risk, percentage	11.70%
Annualized Rental Income, Excluding Properties Classified as Discontinued Operations \| Geographic Concentration Risk \| Virginia
Concentration Risk [Line Items]
Concentration risk, percentage	11%
Annualized Rental Income, Excluding Properties Classified as Discontinued Operations \| Geographic Concentration Risk \| Illinois
Concentration Risk [Line Items]
Concentration risk, percentage	10.80%
Annualized Rental Income, Excluding Properties Classified as Discontinued Operations \| Geographic Concentration Risk \| Washington, D.C.
Concentration Risk [Line Items]
Concentration risk, percentage	10.50%
Annualized Rental Income, Excluding Properties Classified as Discontinued Operations \| Geographic Concentration Risk \| Georgia
Concentration Risk [Line Items]
Concentration risk, percentage	9%

Indebtedness - Outstanding Debt

Indebtedness - Outstanding Debt (Details) - USD ($) $ in Thousands	1 Months Ended		12 Months Ended
	Oct. 31, 2022	Apr. 30, 2022	Dec. 31, 2021	Dec. 31, 2022	Jun. 30, 2022
Debt Instrument [Line Items]
Borrowings outstanding			$ 2,610,301	$ 2,457,000
Unamortized debt premiums, discounts and issuance costs			(32,351)	(24,208)
Total borrowings outstanding			2,577,950	$ 2,432,792
Mortgage note payable, 4.220% interest rate, due in 2022
Debt Instrument [Line Items]
Borrowings outstanding			25,055
Mortgage note payable, 4.800% interest rate, due in 2023
Debt Instrument [Line Items]
Interest rate (as a percent)	4.80%
Senior Unsecured Notes \| Senior unsecured notes, 4.00% interest rate, due in 2022
Debt Instrument [Line Items]
Interest rate (as a percent)				4%	4%
Borrowings outstanding			300,000	$ 0
Senior Unsecured Notes \| Senior unsecured notes, 4.25% interest rate, due in 2024
Debt Instrument [Line Items]
Interest rate (as a percent)				4.25%
Borrowings outstanding			350,000	$ 350,000
Senior Unsecured Notes \| Senior unsecured notes, 4.50% interest rate, due in 2025
Debt Instrument [Line Items]
Interest rate (as a percent)				4.50%
Borrowings outstanding			650,000	$ 650,000
Senior Unsecured Notes \| Senior unsecured notes, 2.650% interest rate, due in 2026
Debt Instrument [Line Items]
Interest rate (as a percent)				2.65%
Borrowings outstanding			300,000	$ 300,000
Senior Unsecured Notes \| Senior unsecured notes, 2.400% interest rate, due in 2027
Debt Instrument [Line Items]
Interest rate (as a percent)				2.40%
Borrowings outstanding			350,000	$ 350,000
Senior Unsecured Notes \| Senior unsecured notes, 3.450% interest rate, due in 2031
Debt Instrument [Line Items]
Interest rate (as a percent)				3.45%
Borrowings outstanding			400,000	$ 400,000
Senior Unsecured Notes \| Senior unsecured notes, 6.375% interest rate, due in 2050
Debt Instrument [Line Items]
Interest rate (as a percent)				6.375%
Borrowings outstanding			162,000	$ 162,000
Mortgage Note Payable \| Mortgage note payable, 4.220% interest rate, due in 2022
Debt Instrument [Line Items]
Interest rate (as a percent)		4.22%		4.22%
Borrowings outstanding			25,055	$ 0
Repayments of debt		$ 24,863
Mortgage Note Payable \| Mortgage note payable, 3.700% interest rate, due in 2023
Debt Instrument [Line Items]
Interest rate (as a percent)				3.70%
Borrowings outstanding			50,000	$ 50,000
Mortgage Note Payable \| Mortgage note payable, 4.800% interest rate, due in 2023
Debt Instrument [Line Items]
Interest rate (as a percent)				4.80%
Borrowings outstanding	$ 22,901		23,246	$ 0
Repayments of debt	$ 22,176		22,176
Revolving credit facility, due in 2023 \| Line of Credit
Debt Instrument [Line Items]
Borrowings outstanding			$ 0	$ 195,000

Indebtedness - Narrative (Detai

Indebtedness - Narrative (Details) $ in Thousands	1 Months Ended		12 Months Ended
Indebtedness - Narrative (Details) $ in Thousands	Oct. 31, 2022 USD ($) property	Apr. 30, 2022 USD ($)	Dec. 31, 2022 USD ($) property extensionOption	Dec. 31, 2021 USD ($) property	Dec. 31, 2020 USD ($)	Feb. 14, 2023 USD ($)	Nov. 30, 2022 USD ($)	Jun. 30, 2022 USD ($)
Debt Instrument [Line Items]
Principal of properties collateralized			$ 50,000
Borrowings outstanding			2,457,000	$ 2,610,301
Gain (loss) on early extinguishment of debt			$ 682	(14,068)	$ (3,839)
Number of properties (in properties) \| property			160
Number of buildings collateralized \| property			1
Book value of properties collateralized			$ 55,071
Mortgage note payable, 4.220% interest rate, due in 2022
Debt Instrument [Line Items]
Borrowings outstanding				$ 25,055
Number of properties (in properties) \| property				1
Mortgage note payable, 4.800% interest rate, due in 2023
Debt Instrument [Line Items]
Interest rate (as a percent)	4.80%
Number of properties (in properties) \| property	1			1
Senior Unsecured Notes \| Senior unsecured notes, 4.00% interest rate, due in 2022
Debt Instrument [Line Items]
Interest rate (as a percent)			4%					4%
Borrowings outstanding			$ 0	$ 300,000
Repurchased face amount								$ 300,000
Gain (loss) on early extinguishment of debt			$ 77
Mortgage Note Payable \| Mortgage note payable, 4.220% interest rate, due in 2022
Debt Instrument [Line Items]
Interest rate (as a percent)		4.22%	4.22%
Borrowings outstanding			$ 0	25,055
Repayments of debt		$ 24,863
Mortgage Note Payable \| Mortgage note payable, 4.800% interest rate, due in 2023
Debt Instrument [Line Items]
Interest rate (as a percent)			4.80%
Borrowings outstanding	$ 22,901		$ 0	23,246
Gain (loss) on early extinguishment of debt			759
Repayments of debt	$ 22,176			$ 22,176
Unsecured Revolving Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity on revolving credit facility			750,000
Principal of properties collateralized			$ 1,950,000
Extension fee							$ 469
Number of contingent options to extend \| extensionOption			1
Contingent option to extend maturity date			6 months
Commitment fee percentage			0.25%
Interest rate (as a percent)			5.40%	1.20%
Weighted average annual interest rate			4%	1.20%	2%
Available borrowings			$ 555,000
Unsecured Revolving Credit Facility \| Subsequent Event
Debt Instrument [Line Items]
Available borrowings						$ 530,000
Unsecured Revolving Credit Facility \| LIBOR
Debt Instrument [Line Items]
Interest rate premium (as a percent)			1.10%
Revolving credit facility, due in 2023 \| Unsecured Revolving Credit Facility
Debt Instrument [Line Items]
Borrowings outstanding			$ 195,000	$ 0
Revolving credit facility, due in 2023 \| Unsecured Revolving Credit Facility \| Subsequent Event
Debt Instrument [Line Items]
Borrowings outstanding						$ 220,000

Indebtedness - Future Principal

Indebtedness - Future Principal Payments (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Apr. 30, 2022	Dec. 31, 2021
Debt Instrument [Line Items]
2023	$ 245,000
2024	350,000
2025	650,000
2026	300,000
2027	350,000
Thereafter	562,000
Total	2,457,000		$ 2,610,301
Borrowings outstanding	2,457,000		2,610,301
Unamortized debt premiums, discounts and issuance	24,208		32,351
Total debt outstanding	2,432,792		2,577,950
Mortgage note payable, 4.220% interest rate, due in 2022
Debt Instrument [Line Items]
Total			25,055
Borrowings outstanding			25,055
Mortgage note payable, 4.220% interest rate, due in 2022 \| Mortgage Note Payable
Debt Instrument [Line Items]
Total	0		25,055
Borrowings outstanding	$ 0		$ 25,055
Interest rate (as a percent)	4.22%	4.22%

Fair Value of Assets and Liab_3

Fair Value of Assets and Liabilities - Financial Instruments (Details) $ in Thousands	1 Months Ended		12 Months Ended
	Oct. 31, 2022 USD ($) property	Apr. 30, 2022 USD ($)	Dec. 31, 2021 USD ($) property	Dec. 31, 2022 USD ($) property	Jun. 30, 2022
Fair Value of Financial Instruments
Senior notes			$ 2,479,772	$ 2,187,875
Mortgage notes payable			98,178	49,917
Unamortized debt premiums, discounts and issuance			32,351	$ 24,208
Number of properties (in properties) \| property				160
Borrowings outstanding			$ 2,610,301	$ 2,457,000
Mortgage note payable, 4.220% interest rate, due in 2022
Fair Value of Financial Instruments
Number of properties (in properties) \| property			1
Borrowings outstanding			$ 25,055
Mortgage note payable, 4.800% interest rate, due in 2023
Fair Value of Financial Instruments
Interest rate (as a percent)	4.80%
Number of properties (in properties) \| property	1		1
Carrying Amount
Fair Value of Financial Instruments
Fair value of financial instruments			$ 2,577,950	2,237,792
Fair Value
Fair Value of Financial Instruments
Fair value of financial instruments			2,661,462	1,840,543
Senior Notes and Mortgages
Fair Value of Financial Instruments
Unamortized debt premiums, discounts and issuance			32,351	$ 24,208
Senior Unsecured Notes \| Senior unsecured notes, 4.00% interest rate, due in 2022
Fair Value of Financial Instruments
Interest rate (as a percent)				4%	4%
Borrowings outstanding			300,000	$ 0
Senior Unsecured Notes \| Senior unsecured notes, 4.25% interest rate, due in 2024
Fair Value of Financial Instruments
Interest rate (as a percent)				4.25%
Borrowings outstanding			350,000	$ 350,000
Senior Unsecured Notes \| Senior unsecured notes, 4.50% interest rate, due in 2025
Fair Value of Financial Instruments
Interest rate (as a percent)				4.50%
Borrowings outstanding			650,000	$ 650,000
Senior Unsecured Notes \| Senior unsecured notes, 2.650% interest rate, due in 2026
Fair Value of Financial Instruments
Interest rate (as a percent)				2.65%
Borrowings outstanding			300,000	$ 300,000
Senior Unsecured Notes \| Senior unsecured notes, 2.400% interest rate, due in 2027
Fair Value of Financial Instruments
Interest rate (as a percent)				2.40%
Borrowings outstanding			350,000	$ 350,000
Senior Unsecured Notes \| Senior unsecured notes, 3.450% interest rate, due in 2031
Fair Value of Financial Instruments
Interest rate (as a percent)				3.45%
Borrowings outstanding			400,000	$ 400,000
Senior Unsecured Notes \| Senior unsecured notes, 6.375% interest rate, due in 2050
Fair Value of Financial Instruments
Interest rate (as a percent)				6.375%
Borrowings outstanding			162,000	$ 162,000
Senior Unsecured Notes \| Carrying Amount \| Senior unsecured notes, 4.00% interest rate, due in 2022
Fair Value of Financial Instruments
Senior notes			299,500	0
Senior Unsecured Notes \| Carrying Amount \| Senior unsecured notes, 4.25% interest rate, due in 2024
Fair Value of Financial Instruments
Senior notes			344,581	346,863
Senior Unsecured Notes \| Carrying Amount \| Senior unsecured notes, 4.50% interest rate, due in 2025
Fair Value of Financial Instruments
Senior notes			639,370	642,818
Senior Unsecured Notes \| Carrying Amount \| Senior unsecured notes, 2.650% interest rate, due in 2026
Fair Value of Financial Instruments
Senior notes			297,213	297,839
Senior Unsecured Notes \| Carrying Amount \| Senior unsecured notes, 2.400% interest rate, due in 2027
Fair Value of Financial Instruments
Senior notes			346,845	347,466
Senior Unsecured Notes \| Carrying Amount \| Senior unsecured notes, 3.450% interest rate, due in 2031
Fair Value of Financial Instruments
Senior notes			395,744	396,178
Senior Unsecured Notes \| Carrying Amount \| Senior unsecured notes, 6.375% interest rate, due in 2050
Fair Value of Financial Instruments
Senior notes			156,519	156,711
Senior Unsecured Notes \| Fair Value \| Senior unsecured notes, 4.00% interest rate, due in 2022
Fair Value of Financial Instruments
Senior notes			304,148	0
Senior Unsecured Notes \| Fair Value \| Senior unsecured notes, 4.25% interest rate, due in 2024
Fair Value of Financial Instruments
Senior notes			365,449	331,601
Senior Unsecured Notes \| Fair Value \| Senior unsecured notes, 4.50% interest rate, due in 2025
Fair Value of Financial Instruments
Senior notes			687,749	589,388
Senior Unsecured Notes \| Fair Value \| Senior unsecured notes, 2.650% interest rate, due in 2026
Fair Value of Financial Instruments
Senior notes			298,502	232,770
Senior Unsecured Notes \| Fair Value \| Senior unsecured notes, 2.400% interest rate, due in 2027
Fair Value of Financial Instruments
Senior notes			339,764	256,606
Senior Unsecured Notes \| Fair Value \| Senior unsecured notes, 3.450% interest rate, due in 2031
Fair Value of Financial Instruments
Senior notes			388,458	268,004
Senior Unsecured Notes \| Fair Value \| Senior unsecured notes, 6.375% interest rate, due in 2050
Fair Value of Financial Instruments
Senior notes			177,098	$ 113,075
Mortgages \| Mortgage note payable, 4.220% interest rate, due in 2022
Fair Value of Financial Instruments
Interest rate (as a percent)		4.22%		4.22%
Borrowings outstanding			25,055	$ 0
Repayments of debt		$ 24,863
Mortgages \| Mortgage note payable, 4.800% interest rate, due in 2023
Fair Value of Financial Instruments
Interest rate (as a percent)				4.80%
Borrowings outstanding	$ 22,901		23,246	$ 0
Repayments of debt	$ 22,176		22,176
Mortgages \| Carrying Amount
Fair Value of Financial Instruments
Mortgage notes payable			98,178	49,917
Mortgages \| Fair Value
Fair Value of Financial Instruments
Mortgage notes payable			$ 100,294	$ 49,099

Shareholders' Equity - Share Aw

Shareholders' Equity - Share Awards (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($) installment shares	Dec. 31, 2021 USD ($) shares	Dec. 31, 2020 USD ($) shares	Dec. 31, 2019 shares
2009 Award Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted (in shares)	172,700	145,800	136,600
Number of installments \| installment	5
Unvested shares (in shares)	231,301	182,224	157,521	106,680
2023 (in shares)	84,941
2024 (in shares)	67,620
2025 (in shares)	50,500
2026 (in shares)	28,240
Estimated future compensation expense for the unvested shares \| $	$ 4,343
Weighted average period of recognition of compensation expenses (in years)	22 months
Compensation expense \| $	$ 2,905	$ 2,868	$ 3,315
Shares available for issuance under plan (in shares)	847,631
Officers and Other Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Issuance of shares, net (in shares)	141,200	117,800	108,600
Issuance of shares, net \| $	$ 2,470	$ 2,994	$ 2,502
Trustees \| 2009 Award Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted (in shares)	3,500	3,500	3,500
Aggregate market value of shares awarded \| $	$ 593	$ 837	$ 745
Market value of common shares awarded to each trustee (in dollars) \| $	$ 66	$ 105	$ 93

Shareholders' Equity - Unvested

Shareholders' Equity - Unvested Shares Activity (Details) - 2009 Award Plan - $ / shares	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Number of Shares
Unvested at the beginning of the period (in shares)	182,224	157,521	106,680
Granted (in shares)	172,700	145,800	136,600
Forfeited (in shares)	(1,900)	(700)	(586)
Vested (in shares)	(121,723)	(120,397)	(85,173)
Unvested at the end of the period (in shares)	231,301	182,224	157,521
Weighted Average Grant Date Fair Value
Unvested at the beginning of the period (in dollars per share)	$ 26.23	$ 29.26	$ 40.16
Granted (in dollars per share)	17.74	26.28	23.77
Forfeited (in dollars per share)	25.97	25.97	43.75
Vested (in dollars per share)	23.24	30.24	34.02
Unvested at the end of the period (in dollars per share)	$ 21.47	$ 26.23	$ 29.26

Shareholders' Equity - Share Re

Shareholders' Equity - Share Repurchases/Sale of Shares (Details) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
	Jan. 12, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Class of Stock [Line Items]
Share repurchases (in shares)		30,821	37,801	19,589
Stock repurchase price (in dollars per share)		$ 17.54	$ 26.55	$ 22.15
Subsequent Event
Class of Stock [Line Items]
Common distributions declared (in dollars per share)	$ 0.55
Dividends payable	$ 26,700

Shareholders' Equity - Distribu

Shareholders' Equity - Distribution (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Equity [Abstract]
Annual Per Share Distribution (in dollars per share)	$ 2.20	$ 2.20	$ 2.20
Total Distributions	$ 106,630	$ 106,368	$ 106,121
Characterization of Distribution, Return of Capital	62.68%	0%	0%
Characterization of Distribution, Ordinary Income	37.32%	100%	100%
Characterization of Distribution, Quality Dividend	0%	0%	0%

SCHEDULE III REAL ESTATE AND _2

SCHEDULE III REAL ESTATE AND ACCUMULATED DEPRECIATION (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($) property building	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Real estate and accumulated depreciation
Number of Properties \| property	157
Encumbrances	$ 49,917
Initial Cost to Company
Land	820,568
Buildings and Equipment	2,531,553
Costs Capitalized Subsequent to Acquisition	588,478
Impairment/ Writedowns	(4,525)
Cost amount carried at Close of Period
Land	821,238
Buildings and Equipment	3,114,836
Total	3,936,074	$ 3,911,086	$ 3,522,143	$ 3,493,231
Accumulated Depreciation	$ (561,458)	$ (495,912)	$ (451,914)	$ (387,656)
445 Jan Davis Drive, Huntsville, AL
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 1,501
Buildings and Equipment	1,492
Costs Capitalized Subsequent to Acquisition	0
Cost amount carried at Close of Period
Land	1,501
Buildings and Equipment	1,492
Total	2,993
Accumulated Depreciation	$ (160)
131 Clayton Street, Montgomery, AL
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 920
Buildings and Equipment	9,084
Costs Capitalized Subsequent to Acquisition	417
Cost amount carried at Close of Period
Land	920
Buildings and Equipment	9,501
Total	10,421
Accumulated Depreciation	$ (2,690)
4344 Carmichael Road, Montgomery, AL
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 1,374
Buildings and Equipment	11,658
Costs Capitalized Subsequent to Acquisition	562
Cost amount carried at Close of Period
Land	1,374
Buildings and Equipment	12,220
Total	13,594
Accumulated Depreciation	$ (2,766)
15451 North 28th Avenue, Phoenix, AZ
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 1,917
Buildings and Equipment	7,416
Costs Capitalized Subsequent to Acquisition	765
Cost amount carried at Close of Period
Land	1,917
Buildings and Equipment	8,181
Total	10,098
Accumulated Depreciation	$ (1,756)
16001 North 28th Ave, Phoenix, AZ
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 3,355
Buildings and Equipment	412
Costs Capitalized Subsequent to Acquisition	1,146
Cost amount carried at Close of Period
Land	3,355
Buildings and Equipment	1,558
Total	4,913
Accumulated Depreciation	$ (273)
711 S 14th Ave, Safford, AZ
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 460
Buildings and Equipment	11,708
Costs Capitalized Subsequent to Acquisition	884
Impairment/ Writedowns	(4,440)
Cost amount carried at Close of Period
Land	364
Buildings and Equipment	8,248
Total	8,612
Accumulated Depreciation	$ (1,381)
Regents Center, Tempe, AZ
Real estate and accumulated depreciation
Number of Properties \| property	2
Initial Cost to Company
Land	$ 4,121
Buildings and Equipment	3,042
Costs Capitalized Subsequent to Acquisition	293
Cost amount carried at Close of Period
Land	4,121
Buildings and Equipment	3,335
Total	7,456
Accumulated Depreciation	$ (660)
Campbell Place, Carlsbad, CA
Real estate and accumulated depreciation
Number of Properties \| property	2
Initial Cost to Company
Land	$ 5,769
Buildings and Equipment	3,871
Costs Capitalized Subsequent to Acquisition	7,517
Cost amount carried at Close of Period
Land	5,769
Buildings and Equipment	11,388
Total	17,157
Accumulated Depreciation	$ (2,438)
Folsom Corporate Center, Folsom, CA
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 2,904
Buildings and Equipment	5,583
Costs Capitalized Subsequent to Acquisition	1,567
Cost amount carried at Close of Period
Land	2,904
Buildings and Equipment	7,150
Total	10,054
Accumulated Depreciation	$ (816)
Bayside Technology Park, Fremont, CA
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 10,784
Buildings and Equipment	648
Costs Capitalized Subsequent to Acquisition	198
Cost amount carried at Close of Period
Land	10,784
Buildings and Equipment	846
Total	11,630
Accumulated Depreciation	$ (110)
10949 N. Mather Boulevard, Rancho Cordova, CA
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 562
Buildings and Equipment	16,923
Costs Capitalized Subsequent to Acquisition	1,012
Cost amount carried at Close of Period
Land	562
Buildings and Equipment	17,935
Total	18,497
Accumulated Depreciation	$ (4,165)
11020 Sun Center Drive, Rancho Cordova, CA
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 1,466
Buildings and Equipment	8,797
Costs Capitalized Subsequent to Acquisition	1,409
Cost amount carried at Close of Period
Land	1,466
Buildings and Equipment	10,206
Total	11,672
Accumulated Depreciation	$ (1,827)
100 Redwood Shores Parkway, Redwood City, CA
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 14,454
Buildings and Equipment	7,721
Costs Capitalized Subsequent to Acquisition	0
Cost amount carried at Close of Period
Land	14,454
Buildings and Equipment	7,721
Total	22,175
Accumulated Depreciation	$ (857)
3875 Atherton Road, Rocklin, CA
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 177
Buildings and Equipment	853
Costs Capitalized Subsequent to Acquisition	23
Cost amount carried at Close of Period
Land	177
Buildings and Equipment	876
Total	1,053
Accumulated Depreciation	$ (95)
801 K Street, Sacramento, CA
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 4,688
Buildings and Equipment	61,994
Costs Capitalized Subsequent to Acquisition	9,465
Cost amount carried at Close of Period
Land	4,688
Buildings and Equipment	71,459
Total	76,147
Accumulated Depreciation	$ (12,968)
9815 Goethe Road, Sacramento, CA
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 1,450
Buildings and Equipment	9,465
Costs Capitalized Subsequent to Acquisition	1,603
Cost amount carried at Close of Period
Land	1,450
Buildings and Equipment	11,068
Total	12,518
Accumulated Depreciation	$ (3,109)
Capitol Place, Sacramento, CA
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 2,290
Buildings and Equipment	35,891
Costs Capitalized Subsequent to Acquisition	8,767
Cost amount carried at Close of Period
Land	2,290
Buildings and Equipment	44,658
Total	46,948
Accumulated Depreciation	$ (14,418)
4560 Viewridge Road, San Diego, CA
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 4,269
Buildings and Equipment	18,316
Costs Capitalized Subsequent to Acquisition	5,146
Cost amount carried at Close of Period
Land	4,347
Buildings and Equipment	23,384
Total	27,731
Accumulated Depreciation	$ (13,942)
2115 O'Nel Drive, San Jose, CA
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 12,305
Buildings and Equipment	5,062
Costs Capitalized Subsequent to Acquisition	350
Cost amount carried at Close of Period
Land	12,305
Buildings and Equipment	5,412
Total	17,717
Accumulated Depreciation	$ (587)
North First Street, San Jose, CA
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 8,311
Buildings and Equipment	4,003
Costs Capitalized Subsequent to Acquisition	411
Cost amount carried at Close of Period
Land	8,311
Buildings and Equipment	4,414
Total	12,725
Accumulated Depreciation	$ (572)
Rio Robles Drive, San Jose, CA
Real estate and accumulated depreciation
Number of Properties \| property	3
Initial Cost to Company
Land	$ 23,687
Buildings and Equipment	13,698
Costs Capitalized Subsequent to Acquisition	12,637
Cost amount carried at Close of Period
Land	23,687
Buildings and Equipment	26,335
Total	50,022
Accumulated Depreciation	$ (2,332)
2450 and 2500 Walsh Avenue, Santa Clara, CA
Real estate and accumulated depreciation
Number of Properties \| property	2
Initial Cost to Company
Land	$ 13,374
Buildings and Equipment	16,651
Costs Capitalized Subsequent to Acquisition	194
Cost amount carried at Close of Period
Land	13,374
Buildings and Equipment	16,845
Total	30,219
Accumulated Depreciation	$ (1,878)
3250 and 3260 Jay Street, Santa Clara, CA
Real estate and accumulated depreciation
Number of Properties \| property	2
Initial Cost to Company
Land	$ 19,899
Buildings and Equipment	14,051
Costs Capitalized Subsequent to Acquisition	20
Cost amount carried at Close of Period
Land	19,899
Buildings and Equipment	14,071
Total	33,970
Accumulated Depreciation	$ (1,558)
603 San Juan Avenue, Stockton, CA
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 563
Buildings and Equipment	5,470
Costs Capitalized Subsequent to Acquisition	93
Cost amount carried at Close of Period
Land	563
Buildings and Equipment	5,563
Total	6,126
Accumulated Depreciation	$ (1,436)
350 West Java Drive, Sunnyvale, CA
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 24,609
Buildings and Equipment	462
Costs Capitalized Subsequent to Acquisition	408
Cost amount carried at Close of Period
Land	24,609
Buildings and Equipment	870
Total	25,479
Accumulated Depreciation	$ (93)
7958 South Chester Street, Centennial, CO
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 6,682
Buildings and Equipment	7,153
Costs Capitalized Subsequent to Acquisition	1,410
Cost amount carried at Close of Period
Land	6,682
Buildings and Equipment	8,563
Total	15,245
Accumulated Depreciation	$ (924)
350 Spectrum Loop, Colorado Springs, CO
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 3,650
Buildings and Equipment	7,732
Costs Capitalized Subsequent to Acquisition	573
Cost amount carried at Close of Period
Land	3,650
Buildings and Equipment	8,305
Total	11,955
Accumulated Depreciation	$ (933)
12795 West Alameda Parkway, Lakewood, CO
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 2,640
Buildings and Equipment	23,777
Costs Capitalized Subsequent to Acquisition	1,535
Cost amount carried at Close of Period
Land	2,640
Buildings and Equipment	25,312
Total	27,952
Accumulated Depreciation	$ (8,177)
Corporate Center, Lakewood, CO
Real estate and accumulated depreciation
Number of Properties \| property	3
Initial Cost to Company
Land	$ 2,887
Buildings and Equipment	27,537
Costs Capitalized Subsequent to Acquisition	2,689
Cost amount carried at Close of Period
Land	2,887
Buildings and Equipment	30,226
Total	33,113
Accumulated Depreciation	$ (14,630)
11 Dupont Circle, NW, Washington DC
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 28,255
Buildings and Equipment	44,743
Costs Capitalized Subsequent to Acquisition	18,712
Cost amount carried at Close of Period
Land	28,255
Buildings and Equipment	63,455
Total	91,710
Accumulated Depreciation	$ (10,002)
1211 Connecticut Avenue, NW, Washington DC
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 30,388
Buildings and Equipment	24,667
Costs Capitalized Subsequent to Acquisition	3,871
Cost amount carried at Close of Period
Land	30,388
Buildings and Equipment	28,538
Total	58,926
Accumulated Depreciation	$ (4,681)
1401 K Street, NW, Washington DC
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 29,215
Buildings and Equipment	34,656
Costs Capitalized Subsequent to Acquisition	7,146
Cost amount carried at Close of Period
Land	29,215
Buildings and Equipment	41,802
Total	71,017
Accumulated Depreciation	$ (7,675)
20 Massachusetts Avenue, Washington DC
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 12,009
Buildings and Equipment	51,527
Costs Capitalized Subsequent to Acquisition	178,984
Cost amount carried at Close of Period
Land	12,231
Buildings and Equipment	230,289
Total	242,520
Accumulated Depreciation	$ (42,535)
440 First Street, NW, Washington DC
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 27,903
Buildings and Equipment	38,624
Costs Capitalized Subsequent to Acquisition	2,315
Cost amount carried at Close of Period
Land	27,903
Buildings and Equipment	40,939
Total	68,842
Accumulated Depreciation	$ (5,678)
625 Indiana Avenue, Washington DC
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 26,000
Buildings and Equipment	25,955
Costs Capitalized Subsequent to Acquisition	10,652
Cost amount carried at Close of Period
Land	26,000
Buildings and Equipment	36,607
Total	62,607
Accumulated Depreciation	$ (10,956)
840 First Street, NE, Washington DC
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 42,727
Buildings and Equipment	73,278
Costs Capitalized Subsequent to Acquisition	3,949
Cost amount carried at Close of Period
Land	42,727
Buildings and Equipment	77,227
Total	119,954
Accumulated Depreciation	$ (11,073)
10350 NW 112th Avenue, Miami, FL
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 4,798
Buildings and Equipment	2,757
Costs Capitalized Subsequent to Acquisition	1,903
Cost amount carried at Close of Period
Land	4,798
Buildings and Equipment	4,660
Total	9,458
Accumulated Depreciation	$ (441)
7850 Southwest 6th Court, Plantation, FL
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 4,800
Buildings and Equipment	30,592
Costs Capitalized Subsequent to Acquisition	1,167
Cost amount carried at Close of Period
Land	4,800
Buildings and Equipment	31,759
Total	36,559
Accumulated Depreciation	$ (9,022)
8900 Grand Oak Circle, Tampa, FL
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 1,100
Buildings and Equipment	11,773
Costs Capitalized Subsequent to Acquisition	1,142
Cost amount carried at Close of Period
Land	1,100
Buildings and Equipment	12,915
Total	14,015
Accumulated Depreciation	$ (3,830)
180 Ted Turner Drive SW, Atlanta, GA
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 5,717
Buildings and Equipment	20,017
Costs Capitalized Subsequent to Acquisition	726
Cost amount carried at Close of Period
Land	5,717
Buildings and Equipment	20,743
Total	26,460
Accumulated Depreciation	$ (5,401)
1224 Hammond Drive, Atlanta GA
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 13,040
Buildings and Equipment	135,459
Costs Capitalized Subsequent to Acquisition	11,627
Cost amount carried at Close of Period
Land	13,040
Buildings and Equipment	147,086
Total	160,126
Accumulated Depreciation	$ (6,189)
Corporate Square, Atlanta, GA
Real estate and accumulated depreciation
Number of Properties \| property	5
Initial Cost to Company
Land	$ 3,996
Buildings and Equipment	29,762
Costs Capitalized Subsequent to Acquisition	28,076
Cost amount carried at Close of Period
Land	3,996
Buildings and Equipment	57,838
Total	61,834
Accumulated Depreciation	$ (20,701)
Executive Park, Atlanta, GA
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 1,521
Buildings and Equipment	11,826
Costs Capitalized Subsequent to Acquisition	4,123
Cost amount carried at Close of Period
Land	1,521
Buildings and Equipment	15,949
Total	17,470
Accumulated Depreciation	$ (8,424)
One Georgia Center, Atlanta, GA
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 10,250
Buildings and Equipment	27,933
Costs Capitalized Subsequent to Acquisition	18,781
Cost amount carried at Close of Period
Land	10,250
Buildings and Equipment	46,714
Total	56,964
Accumulated Depreciation	$ (11,782)
One Primerica Parkway, Duluth, GA
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 6,927
Buildings and Equipment	22,951
Costs Capitalized Subsequent to Acquisition	0
Cost amount carried at Close of Period
Land	6,927
Buildings and Equipment	22,951
Total	29,878
Accumulated Depreciation	$ (2,545)
4712 Southpark Boulevard, Ellenwood, GA
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 1,390
Buildings and Equipment	19,635
Costs Capitalized Subsequent to Acquisition	248
Cost amount carried at Close of Period
Land	1,390
Buildings and Equipment	19,883
Total	21,273
Accumulated Depreciation	$ (5,152)
8305 NW 62nd Avenue, Johnston, IA
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 2,649
Buildings and Equipment	7,997
Costs Capitalized Subsequent to Acquisition	0
Cost amount carried at Close of Period
Land	2,649
Buildings and Equipment	7,997
Total	10,646
Accumulated Depreciation	$ (887)
1185, 1249 & 1387 S. Vinnell Way, Boise, ID
Real estate and accumulated depreciation
Number of Properties \| property	3
Initial Cost to Company
Land	$ 3,390
Buildings and Equipment	29,026
Costs Capitalized Subsequent to Acquisition	1,101
Cost amount carried at Close of Period
Land	3,390
Buildings and Equipment	30,127
Total	33,517
Accumulated Depreciation	$ (7,835)
2020 S. Arlington Heights, Arlington Heights, IL
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 1,450
Buildings and Equipment	13,588
Costs Capitalized Subsequent to Acquisition	2,139
Cost amount carried at Close of Period
Land	1,450
Buildings and Equipment	15,727
Total	17,177
Accumulated Depreciation	$ (4,654)
400 South Jefferson Street, Chicago, IL
Real estate and accumulated depreciation
Number of Properties \| property	1
Encumbrances	$ 49,917
Initial Cost to Company
Land	19,379
Buildings and Equipment	20,115
Costs Capitalized Subsequent to Acquisition	783
Cost amount carried at Close of Period
Land	19,379
Buildings and Equipment	20,898
Total	40,277
Accumulated Depreciation	$ (2,381)
1000 W. Fulton, Chicago IL
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 42,935
Buildings and Equipment	252,914
Costs Capitalized Subsequent to Acquisition	94
Cost amount carried at Close of Period
Land	42,935
Buildings and Equipment	253,008
Total	295,943
Accumulated Depreciation	$ (12,816)
HUB 1415, Naperville IL
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 12,333
Buildings and Equipment	20,586
Costs Capitalized Subsequent to Acquisition	16,211
Cost amount carried at Close of Period
Land	12,333
Buildings and Equipment	36,797
Total	49,130
Accumulated Depreciation	$ (4,616)
440 North Fairway Drive, Vernon Hills, IL
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 4,465
Buildings and Equipment	441
Costs Capitalized Subsequent to Acquisition	10
Cost amount carried at Close of Period
Land	4,465
Buildings and Equipment	451
Total	4,916
Accumulated Depreciation	$ (51)
7601 and 7635 Interactive Way, Indianapolis, IN
Real estate and accumulated depreciation
Number of Properties \| property	2
Initial Cost to Company
Land	$ 3,337
Buildings and Equipment	14,522
Costs Capitalized Subsequent to Acquisition	34
Cost amount carried at Close of Period
Land	3,337
Buildings and Equipment	14,556
Total	17,893
Accumulated Depreciation	$ (1,517)
Intech Park, Indianapolis, IN
Real estate and accumulated depreciation
Number of Properties \| property	3
Initial Cost to Company
Land	$ 4,170
Buildings and Equipment	69,759
Costs Capitalized Subsequent to Acquisition	10,389
Cost amount carried at Close of Period
Land	4,170
Buildings and Equipment	80,148
Total	84,318
Accumulated Depreciation	$ (23,417)
7125 Industrial Road, Florence, KY
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 1,698
Buildings and Equipment	11,722
Costs Capitalized Subsequent to Acquisition	293
Cost amount carried at Close of Period
Land	1,698
Buildings and Equipment	12,015
Total	13,713
Accumulated Depreciation	$ (3,030)
251 Causeway Street, Boston, MA
Real estate and accumulated depreciation
Number of Properties \| property	3
Initial Cost to Company
Land	$ 26,851
Buildings and Equipment	36,756
Costs Capitalized Subsequent to Acquisition	4,662
Cost amount carried at Close of Period
Land	26,851
Buildings and Equipment	41,418
Total	68,269
Accumulated Depreciation	$ (7,688)
300 Billerica road, Chelmsford, MA
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 2,223
Buildings and Equipment	0
Costs Capitalized Subsequent to Acquisition	45
Cost amount carried at Close of Period
Land	2,223
Buildings and Equipment	45
Total	2,268
Accumulated Depreciation	$ (13)
330 Billerica road, Chelmsford, MA
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 2,477
Buildings and Equipment	0
Costs Capitalized Subsequent to Acquisition	10,103
Cost amount carried at Close of Period
Land	2,477
Buildings and Equipment	10,103
Total	12,580
Accumulated Depreciation	$ (1,113)
75 Pleasant Street, Malden, MA
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 1,050
Buildings and Equipment	31,086
Costs Capitalized Subsequent to Acquisition	856
Cost amount carried at Close of Period
Land	1,050
Buildings and Equipment	31,942
Total	32,992
Accumulated Depreciation	$ (10,300)
25 Newport Avenue, Quincy, MA
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 2,700
Buildings and Equipment	9,199
Costs Capitalized Subsequent to Acquisition	2,143
Cost amount carried at Close of Period
Land	2,700
Buildings and Equipment	11,342
Total	14,042
Accumulated Depreciation	$ (3,154)
314 Littleton Road, Westford, MA
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 5,691
Buildings and Equipment	8,487
Costs Capitalized Subsequent to Acquisition	100
Cost amount carried at Close of Period
Land	5,691
Buildings and Equipment	8,587
Total	14,278
Accumulated Depreciation	$ (956)
Annapolis Commerce Center, Annapolis, MD
Real estate and accumulated depreciation
Number of Properties \| property	2
Initial Cost to Company
Land	$ 4,057
Buildings and Equipment	7,665
Costs Capitalized Subsequent to Acquisition	4,628
Cost amount carried at Close of Period
Land	4,057
Buildings and Equipment	12,293
Total	16,350
Accumulated Depreciation	$ (1,679)
4201 Patterson Avenue, Baltimore, MD
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 901
Buildings and Equipment	8,097
Costs Capitalized Subsequent to Acquisition	4,134
Impairment/ Writedowns	(85)
Cost amount carried at Close of Period
Land	893
Buildings and Equipment	12,154
Total	13,047
Accumulated Depreciation	$ (6,744)
7001 Columbia Gateway Drive, Columbia, MD
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 5,642
Buildings and Equipment	10,352
Costs Capitalized Subsequent to Acquisition	569
Cost amount carried at Close of Period
Land	5,642
Buildings and Equipment	10,921
Total	16,563
Accumulated Depreciation	$ (1,271)
Hillside Center, Columbia, MD
Real estate and accumulated depreciation
Number of Properties \| property	2
Initial Cost to Company
Land	$ 3,437
Buildings and Equipment	4,228
Costs Capitalized Subsequent to Acquisition	971
Cost amount carried at Close of Period
Land	3,437
Buildings and Equipment	5,199
Total	8,636
Accumulated Depreciation	$ (859)
TenThreeTwenty, Columbia, MD
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 3,126
Buildings and Equipment	16,361
Costs Capitalized Subsequent to Acquisition	3,681
Cost amount carried at Close of Period
Land	3,126
Buildings and Equipment	20,042
Total	23,168
Accumulated Depreciation	$ (2,782)
3300 75th Avenue, Landover, MD
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 4,110
Buildings and Equipment	36,371
Costs Capitalized Subsequent to Acquisition	3,302
Cost amount carried at Close of Period
Land	4,110
Buildings and Equipment	39,673
Total	43,783
Accumulated Depreciation	$ (12,615)
Redland 520/530, Rockville, MD
Real estate and accumulated depreciation
Number of Properties \| property	3
Initial Cost to Company
Land	$ 12,714
Buildings and Equipment	61,377
Costs Capitalized Subsequent to Acquisition	6,951
Cost amount carried at Close of Period
Land	12,714
Buildings and Equipment	68,328
Total	81,042
Accumulated Depreciation	$ (8,937)
Redland 540, Rockville, MD
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 10,740
Buildings and Equipment	17,714
Costs Capitalized Subsequent to Acquisition	6,231
Cost amount carried at Close of Period
Land	10,740
Buildings and Equipment	23,945
Total	34,685
Accumulated Depreciation	$ (5,635)
Rutherford Business Park, Windsor Mill, MD
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 1,598
Buildings and Equipment	10,219
Costs Capitalized Subsequent to Acquisition	545
Cost amount carried at Close of Period
Land	1,598
Buildings and Equipment	10,764
Total	12,362
Accumulated Depreciation	$ (2,741)
3550 Green Court, Ann Arbor, MI
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 3,630
Buildings and Equipment	4,857
Costs Capitalized Subsequent to Acquisition	0
Cost amount carried at Close of Period
Land	3,630
Buildings and Equipment	4,857
Total	8,487
Accumulated Depreciation	$ (571)
11411 E. Jefferson Avenue, Detroit, MI
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 630
Buildings and Equipment	18,002
Costs Capitalized Subsequent to Acquisition	567
Cost amount carried at Close of Period
Land	630
Buildings and Equipment	18,569
Total	19,199
Accumulated Depreciation	$ (5,839)
Rosedale Corporate Plaza, Roseville, MN
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 672
Buildings and Equipment	6,045
Costs Capitalized Subsequent to Acquisition	1,547
Cost amount carried at Close of Period
Land	672
Buildings and Equipment	7,592
Total	8,264
Accumulated Depreciation	$ (4,636)
1300 Summit Street, Kansas City, MO
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 2,776
Buildings and Equipment	12,070
Costs Capitalized Subsequent to Acquisition	900
Cost amount carried at Close of Period
Land	2,776
Buildings and Equipment	12,970
Total	15,746
Accumulated Depreciation	$ (3,334)
2555 Grand Boulevard, Kansas City, MO
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 4,209
Buildings and Equipment	51,522
Costs Capitalized Subsequent to Acquisition	4,778
Cost amount carried at Close of Period
Land	4,209
Buildings and Equipment	56,300
Total	60,509
Accumulated Depreciation	$ (6,356)
4241 NE 34th Street, Kansas City, MO
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 1,133
Buildings and Equipment	5,649
Costs Capitalized Subsequent to Acquisition	4,908
Cost amount carried at Close of Period
Land	1,470
Buildings and Equipment	10,220
Total	11,690
Accumulated Depreciation	$ (5,127)
1220 Echelon Parkway, Jackson, MS
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 440
Buildings and Equipment	25,458
Costs Capitalized Subsequent to Acquisition	561
Cost amount carried at Close of Period
Land	440
Buildings and Equipment	26,019
Total	26,459
Accumulated Depreciation	$ (6,800)
2300 and 2400 Yorkmont Road, Charlotte, NC
Real estate and accumulated depreciation
Number of Properties \| property	2
Initial Cost to Company
Land	$ 1,334
Buildings and Equipment	19,075
Costs Capitalized Subsequent to Acquisition	3,200
Cost amount carried at Close of Period
Land	1,334
Buildings and Equipment	22,275
Total	23,609
Accumulated Depreciation	$ (2,725)
18010 and 18020 Burt Street, Omaha, NE
Real estate and accumulated depreciation
Number of Properties \| property	2
Initial Cost to Company
Land	$ 6,977
Buildings and Equipment	12,500
Costs Capitalized Subsequent to Acquisition	0
Cost amount carried at Close of Period
Land	6,977
Buildings and Equipment	12,500
Total	19,477
Accumulated Depreciation	$ (1,386)
500 Charles Ewing Boulevard, Ewing, NJ
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 4,808
Buildings and Equipment	26,002
Costs Capitalized Subsequent to Acquisition	281
Cost amount carried at Close of Period
Land	4,808
Buildings and Equipment	26,283
Total	31,091
Accumulated Depreciation	$ (2,883)
299 Jefferson Road, Parsippany, NJ
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 4,543
Buildings and Equipment	2,914
Costs Capitalized Subsequent to Acquisition	935
Cost amount carried at Close of Period
Land	4,543
Buildings and Equipment	3,849
Total	8,392
Accumulated Depreciation	$ (554)
One Jefferson Road, Parsippany, NJ
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 4,415
Buildings and Equipment	5,249
Costs Capitalized Subsequent to Acquisition	63
Cost amount carried at Close of Period
Land	4,415
Buildings and Equipment	5,312
Total	9,727
Accumulated Depreciation	$ (588)
Airline Corporate Center, Colonie, NY
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 790
Buildings and Equipment	6,400
Costs Capitalized Subsequent to Acquisition	1,827
Cost amount carried at Close of Period
Land	790
Buildings and Equipment	8,227
Total	9,017
Accumulated Depreciation	$ (1,876)
1212 Pittsford - Victor Road, Pittsford, NY
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 608
Buildings and Equipment	78
Costs Capitalized Subsequent to Acquisition	847
Cost amount carried at Close of Period
Land	608
Buildings and Equipment	925
Total	1,533
Accumulated Depreciation	$ (106)
2231 Schrock Road, Columbus, OH
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 716
Buildings and Equipment	217
Costs Capitalized Subsequent to Acquisition	578
Cost amount carried at Close of Period
Land	716
Buildings and Equipment	795
Total	1,511
Accumulated Depreciation	$ (98)
8800 Tinicum Boulevard, Philadelphia, PA
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 5,573
Buildings and Equipment	22,686
Costs Capitalized Subsequent to Acquisition	5,934
Cost amount carried at Close of Period
Land	5,573
Buildings and Equipment	28,620
Total	34,193
Accumulated Depreciation	$ (2,738)
446 Wrenplace Road, Fort Mill, SC
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 5,031
Buildings and Equipment	22,524
Costs Capitalized Subsequent to Acquisition	0
Cost amount carried at Close of Period
Land	5,031
Buildings and Equipment	22,524
Total	27,555
Accumulated Depreciation	$ (1,140)
9680 Old Bailes Road, Fort Mill, SC
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 834
Buildings and Equipment	2,944
Costs Capitalized Subsequent to Acquisition	53
Cost amount carried at Close of Period
Land	834
Buildings and Equipment	2,997
Total	3,831
Accumulated Depreciation	$ (333)
16001 North Dallas Parkway, Addison, TX
Real estate and accumulated depreciation
Number of Properties \| property	2
Initial Cost to Company
Land	$ 10,282
Buildings and Equipment	63,071
Costs Capitalized Subsequent to Acquisition	1,911
Cost amount carried at Close of Period
Land	10,282
Buildings and Equipment	64,982
Total	75,264
Accumulated Depreciation	$ (7,529)
Research Park, Austin, TX
Real estate and accumulated depreciation
Number of Properties \| property	2
Initial Cost to Company
Land	$ 4,258
Buildings and Equipment	13,747
Costs Capitalized Subsequent to Acquisition	199
Cost amount carried at Close of Period
Land	4,258
Buildings and Equipment	13,946
Total	18,204
Accumulated Depreciation	$ (2,787)
10451 Clay Road, Houston, TX
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 5,495
Buildings and Equipment	10,253
Costs Capitalized Subsequent to Acquisition	2,432
Cost amount carried at Close of Period
Land	5,495
Buildings and Equipment	12,685
Total	18,180
Accumulated Depreciation	$ (1,139)
202 North Castlegory Road, Houston, TX
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 863
Buildings and Equipment	5,024
Costs Capitalized Subsequent to Acquisition	8
Cost amount carried at Close of Period
Land	863
Buildings and Equipment	5,032
Total	5,895
Accumulated Depreciation	$ (524)
4221 W. John Carpenter Freeway, Irving, TX
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 1,413
Buildings and Equipment	2,365
Costs Capitalized Subsequent to Acquisition	1,843
Cost amount carried at Close of Period
Land	1,413
Buildings and Equipment	4,208
Total	5,621
Accumulated Depreciation	$ (1,091)
8675, 8701-8711 Freeport Pkwy and 8901 Esters Boulevard, Irving, TX
Real estate and accumulated depreciation
Number of Properties \| property	3
Initial Cost to Company
Land	$ 10,185
Buildings and Equipment	31,566
Costs Capitalized Subsequent to Acquisition	68
Cost amount carried at Close of Period
Land	10,185
Buildings and Equipment	31,634
Total	41,819
Accumulated Depreciation	$ (3,500)
1511 East Common Street, New Braunfels, TX
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 4,965
Buildings and Equipment	1,266
Costs Capitalized Subsequent to Acquisition	251
Cost amount carried at Close of Period
Land	4,965
Buildings and Equipment	1,517
Total	6,482
Accumulated Depreciation	$ (223)
2900 West Plano Parkway, Plano, TX
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 6,819
Buildings and Equipment	8,831
Costs Capitalized Subsequent to Acquisition	0
Cost amount carried at Close of Period
Land	6,819
Buildings and Equipment	8,831
Total	15,650
Accumulated Depreciation	$ (979)
3400 West Plano Parkway, Plano, TX
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 4,543
Buildings and Equipment	15,964
Costs Capitalized Subsequent to Acquisition	321
Cost amount carried at Close of Period
Land	4,543
Buildings and Equipment	16,285
Total	20,828
Accumulated Depreciation	$ (1,828)
3600 Weismann Boulevard, San Antonio, TX
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 3,493
Buildings and Equipment	6,662
Costs Capitalized Subsequent to Acquisition	3,309
Cost amount carried at Close of Period
Land	3,493
Buildings and Equipment	9,971
Total	13,464
Accumulated Depreciation	$ (1,714)
701 Clay Road, Waco, TX
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 2,030
Buildings and Equipment	8,708
Costs Capitalized Subsequent to Acquisition	14,479
Cost amount carried at Close of Period
Land	2,060
Buildings and Equipment	23,157
Total	25,217
Accumulated Depreciation	$ (8,473)
1800 Novell Place, Provo, UT
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 7,487
Buildings and Equipment	43,487
Costs Capitalized Subsequent to Acquisition	11,404
Cost amount carried at Close of Period
Land	7,487
Buildings and Equipment	54,891
Total	62,378
Accumulated Depreciation	$ (5,233)
4885-4931 North 300 West, Provo, UT
Real estate and accumulated depreciation
Number of Properties \| property	2
Initial Cost to Company
Land	$ 3,915
Buildings and Equipment	9,429
Costs Capitalized Subsequent to Acquisition	21
Cost amount carried at Close of Period
Land	3,915
Buildings and Equipment	9,450
Total	13,365
Accumulated Depreciation	$ (1,113)
14660, 14672 and 14668 Lee Road, Chantilly, VA
Real estate and accumulated depreciation
Number of Properties \| property	3
Initial Cost to Company
Land	$ 6,966
Buildings and Equipment	74,214
Costs Capitalized Subsequent to Acquisition	7,567
Cost amount carried at Close of Period
Land	6,966
Buildings and Equipment	81,781
Total	88,747
Accumulated Depreciation	$ (12,503)
Enterchange At Meadowville, Chester, VA
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 1,478
Buildings and Equipment	9,594
Costs Capitalized Subsequent to Acquisition	1,369
Cost amount carried at Close of Period
Land	1,478
Buildings and Equipment	10,963
Total	12,441
Accumulated Depreciation	$ (2,367)
7987 Ashton Avenue, Manassas, VA
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 1,562
Buildings and Equipment	8,253
Costs Capitalized Subsequent to Acquisition	1,069
Cost amount carried at Close of Period
Land	1,562
Buildings and Equipment	9,322
Total	10,884
Accumulated Depreciation	$ (1,628)
Two Commercial Place, Norfolk, VA
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 4,494
Buildings and Equipment	21,508
Costs Capitalized Subsequent to Acquisition	780
Cost amount carried at Close of Period
Land	4,494
Buildings and Equipment	22,288
Total	26,782
Accumulated Depreciation	$ (2,350)
1759 Business Center Drive, Reston, VA
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 4,033
Buildings and Equipment	28,517
Costs Capitalized Subsequent to Acquisition	1,562
Cost amount carried at Close of Period
Land	4,033
Buildings and Equipment	30,079
Total	34,112
Accumulated Depreciation	$ (6,349)
1760 Business Center Drive, Reston, VA
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 5,033
Buildings and Equipment	50,141
Costs Capitalized Subsequent to Acquisition	6,251
Cost amount carried at Close of Period
Land	5,033
Buildings and Equipment	56,392
Total	61,425
Accumulated Depreciation	$ (11,959)
1775 Wiehle Avenue, Reston, VA
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 4,138
Buildings and Equipment	26,120
Costs Capitalized Subsequent to Acquisition	4,552
Cost amount carried at Close of Period
Land	4,138
Buildings and Equipment	30,672
Total	34,810
Accumulated Depreciation	$ (4,218)
9201 Forest Hill Avenue, Richmond, VA
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 1,344
Buildings and Equipment	375
Costs Capitalized Subsequent to Acquisition	580
Cost amount carried at Close of Period
Land	1,344
Buildings and Equipment	955
Total	2,299
Accumulated Depreciation	$ (165)
9960 Mayland Drive, Richmond, VA
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 2,614
Buildings and Equipment	15,930
Costs Capitalized Subsequent to Acquisition	3,812
Cost amount carried at Close of Period
Land	2,614
Buildings and Equipment	19,742
Total	22,356
Accumulated Depreciation	$ (4,402)
1751 Blue Hills Drive, Roanoke, VA
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 2,689
Buildings and Equipment	7,761
Costs Capitalized Subsequent to Acquisition	0
Cost amount carried at Close of Period
Land	2,689
Buildings and Equipment	7,761
Total	10,450
Accumulated Depreciation	$ (861)
Atlantic Corporate Park, Sterling, VA
Real estate and accumulated depreciation
Number of Properties \| property	2
Initial Cost to Company
Land	$ 5,752
Buildings and Equipment	29,316
Costs Capitalized Subsequent to Acquisition	2,885
Cost amount carried at Close of Period
Land	5,752
Buildings and Equipment	32,201
Total	37,953
Accumulated Depreciation	$ (4,536)
Orbital Sciences Campus, Sterling, VA
Real estate and accumulated depreciation
Number of Properties \| property	3
Initial Cost to Company
Land	$ 12,275
Buildings and Equipment	19,320
Costs Capitalized Subsequent to Acquisition	1,876
Cost amount carried at Close of Period
Land	12,275
Buildings and Equipment	21,196
Total	33,471
Accumulated Depreciation	$ (2,429)
Sterling Park Business Center, Sterling, VA
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 5,871
Buildings and Equipment	44,324
Costs Capitalized Subsequent to Acquisition	109
Cost amount carried at Close of Period
Land	5,871
Buildings and Equipment	44,433
Total	50,304
Accumulated Depreciation	$ (5,832)
65 Bowdoin Street, S. Burlington VT
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 700
Buildings and Equipment	8,416
Costs Capitalized Subsequent to Acquisition	140
Cost amount carried at Close of Period
Land	700
Buildings and Equipment	8,556
Total	9,256
Accumulated Depreciation	$ (2,742)
Stevens Center, Richland, WA
Real estate and accumulated depreciation
Number of Properties \| property	2
Initial Cost to Company
Land	$ 3,970
Buildings and Equipment	17,035
Costs Capitalized Subsequent to Acquisition	4,737
Cost amount carried at Close of Period
Land	4,042
Buildings and Equipment	21,700
Total	25,742
Accumulated Depreciation	$ (12,262)
Unison Elliott Bay-Lab Space, Seattle, WA
Real estate and accumulated depreciation
Number of Properties \| property	2
Initial Cost to Company
Land	$ 17,316
Buildings and Equipment	34,281
Costs Capitalized Subsequent to Acquisition	49,266
Cost amount carried at Close of Period
Land	17,316
Buildings and Equipment	83,547
Total	100,863
Accumulated Depreciation	$ (4,180)
Unison Elliott Bay-Office Space, Seattle, WA
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 9,324
Buildings and Equipment	18,459
Costs Capitalized Subsequent to Acquisition	2,122
Cost amount carried at Close of Period
Land	9,324
Buildings and Equipment	20,581
Total	29,905
Accumulated Depreciation	$ (2,251)
5353 Yellowstone Road, Cheyenne, WY
Real estate and accumulated depreciation
Number of Properties \| property	1
Initial Cost to Company
Land	$ 1,915
Buildings and Equipment	8,217
Costs Capitalized Subsequent to Acquisition	2,085
Cost amount carried at Close of Period
Land	1,950
Buildings and Equipment	10,267
Total	12,217
Accumulated Depreciation	$ (5,872)
Properties Held for Sale
Real estate and accumulated depreciation
Number of Properties \| property	3
Encumbrances	$ 0
Initial Cost to Company
Land	913
Buildings and Equipment	1,099
Costs Capitalized Subsequent to Acquisition	572
Impairment/ Writedowns	0
Cost amount carried at Close of Period
Land	913
Buildings and Equipment	1,671
Total	2,584
Accumulated Depreciation	$ (188)
Properties Held for Sale \| Parham Place, Richmond, VA
Real estate and accumulated depreciation
Number of Properties \| building	3
Initial Cost to Company
Land	$ 913
Buildings and Equipment	1,099
Costs Capitalized Subsequent to Acquisition	572
Impairment/ Writedowns	0
Cost amount carried at Close of Period
Land	913
Buildings and Equipment	1,671
Total	2,584
Accumulated Depreciation	$ (188)
Total Real Estate Assets
Real estate and accumulated depreciation
Number of Properties \| property	160
Encumbrances	$ 49,917
Initial Cost to Company
Land	821,481
Buildings and Equipment	2,532,652
Costs Capitalized Subsequent to Acquisition	589,050
Impairment/ Writedowns	(4,525)
Cost amount carried at Close of Period
Land	822,151
Buildings and Equipment	3,116,507
Total	3,938,658
Accumulated Depreciation	$ (561,646)

SCHEDULE III REAL ESTATE AND _3

SCHEDULE III REAL ESTATE AND ACCUMULATED DEPRECIATION - Additional Information (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($)
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation Disclosure [Abstract]
Mortgage debt, net	$ 83
Aggregate cost for federal income tax purposes	$ 7,360,476
Useful life of buildings and improvements	40 years
Useful life of equipment	7 years

SCHEDULE III REAL ESTATE AND _4

SCHEDULE III REAL ESTATE AND ACCUMULATED DEPRECIATION - Carrying Amount and Accumulated Depreciation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Real Estate Properties
Balance at the beginning of the period	$ 3,911,086	$ 3,522,143	$ 3,493,231
Additions	222,951	584,805	122,116
Loss on asset impairment	(17,303)	(58,696)	(2,954)
Disposals	(173,841)	(72,137)	(31,193)
Cost basis adjustment	(4,235)	(37,239)	(3,968)
Reclassification of assets of properties held for sale	(2,584)	(27,790)	(55,089)
Balance at the end of the period	3,936,074	3,911,086	3,522,143
Accumulated Depreciation
Balance at the beginning of the period	495,912	451,914	387,656
Additions	96,966	92,266	83,828
Loss on asset impairment	0	0	0
Disposals	(26,997)	(8,675)	(13,125)
Cost basis adjustment	(4,235)	(37,239)	(3,968)
Reclassification of assets of properties held for sale	(188)	(2,354)	(2,477)
Balance at the end of the period	$ 561,458	$ 495,912	$ 451,914