Office Properties Income Trust (OPI) 10-K 20 Feb 20 2019 FY Annual report Financial data

Cover Page

Cover Page - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2019	Feb. 19, 2020	Jun. 28, 2019
Document Information [Line Items]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2019
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
Entity Shell Company	false
Entity Public Float			$ 1.2
Entity Common Stock, Shares Outstanding		48,201,531
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 2020 Annual Meeting of Shareholders, to be filed with the Securities and Exchange Commission within 120 days after the fiscal year ended December 31, 2019.
Entity Central Index Key	0001456772
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
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
5.875% Senior Notes Due 2046
Document Information [Line Items]
Title of 12(b) Security	5.875% Senior Notes due 2046
Trading Symbol	OPINI
Security Exchange Name	NASDAQ

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Real estate properties:
Land	$ 840,550	$ 924,164
Buildings and improvements	2,652,681	3,020,472
Total real estate properties, gross	3,493,231	3,944,636
Accumulated depreciation	(387,656)	(375,147)
Total real estate properties, net	3,105,575	3,569,489
Assets of properties held for sale	70,877	253,501
Investments in unconsolidated joint ventures	39,756	43,665
Acquired real estate leases, net	732,382	1,056,558
Cash and cash equivalents	93,744	35,349
Restricted cash	6,952	3,594
Rents receivable	83,556	72,051
Deferred leasing costs, net	40,107	25,672
Other assets, net	20,187	178,704
Total assets	4,193,136	5,238,583
LIABILITIES AND SHAREHOLDERS’ EQUITY
Unsecured revolving credit facility	0	175,000
Unsecured term loans, net	0	387,152
Senior unsecured notes, net	2,017,379	2,357,497
Mortgage notes payable, net	309,946	335,241
Liabilities of properties held for sale	14,693	4,271
Accounts payable and other liabilities	125,048	145,536
Due to related persons	7,141	34,887
Assumed real estate lease obligations, net	13,175	20,031
Total liabilities	2,487,382	3,459,615
Commitments and contingencies
Shareholders’ equity:
Common shares of beneficial interest, $.01 par value: 200,000,000 shares authorized, 48,201,941 and 48,082,903 shares issued and outstanding, respectively	482	481
Additional paid in capital	2,612,425	2,609,801
Cumulative net income	177,217	146,882
Cumulative other comprehensive income (loss)	(200)	106
Cumulative common distributions	(1,084,170)	(978,302)
Total shareholders’ equity	1,705,754	1,778,968
Total liabilities and shareholders’ equity	$ 4,193,136	$ 5,238,583

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Dec. 31, 2019	Dec. 31, 2018
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)	48,201,941	48,082,903
Common shares of beneficial interest, shares outstanding (in shares)	48,201,941	48,082,903

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Statement [Abstract]
Revenues	$ 678,404	$ 426,560	$ 316,532
Expenses:
Real estate taxes	73,717	49,708	37,942
Utility expenses	34,302	26,425	20,998
Other operating expenses	120,943	89,610	65,349
Depreciation and amortization	289,885	162,488	109,588
Loss on impairment of real estate	22,255	8,630	9,490
Acquisition and transaction related costs	682	14,508	0
General and administrative	32,728	24,922	18,847
Total expenses	574,512	376,291	262,214
Gain on sale of real estate	105,131	20,661	0
Dividend income	1,960	1,337	1,216
Loss on equity securities, net	(44,007)	(7,552)	0
Interest income	1,045	639	1,962
Interest expense (including net amortization of debt premiums, discounts and issuance costs of $10,740, $3,626 and $3,420, respectively)	(134,880)	(89,865)	(65,406)
Loss on early extinguishment of debt	(769)	(709)	(1,715)
Income (loss) from continuing operations before income tax expense and equity in net losses of investees	32,372	(25,220)	(9,625)
Income tax expense	(778)	(117)	(101)
Equity in net losses of investees	(1,259)	(2,269)	(13)
Income (loss) from continuing operations	30,335	(27,606)	(9,739)
Income from discontinued operations	0	5,722	21,829
Net income (loss)	30,335	(21,884)	12,090
Other comprehensive income (loss):
Unrealized gain on equity securities	0	0	24,042
Unrealized loss on financial instrument	(200)
Unrealized loss on financial instrument		0	0
Equity in unrealized gain (loss) of investees	(106)	(40)	9,428
Other comprehensive income (loss)	(306)	(40)	33,470
Comprehensive income (loss)	30,029	(21,924)	45,560
Net income (loss)	30,335	(21,884)	12,090
Preferred units of limited partnership distributions	0	(371)	(275)
Net income (loss) available for common shareholders	$ 30,335	$ (22,255)	$ 11,815
Weighted average common shares outstanding (basic) (in shares)	48,062	24,830	21,158
Weighted average common shares outstanding (diluted) (in shares)	48,062	24,830	21,158
Per common share amounts (basic and diluted):
Income (loss) from continuing operations (in dollars per share)	$ 0.63	$ (1.13)	$ (0.47)
Income from discontinued operations (in dollars per share)	0	0.23	1.03
Net income (loss) available for common shareholders (in dollars per share)	$ 0.63	$ (0.90)	$ 0.56

CONSOLIDATED STATEMENTS OF CO_2

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Statement [Abstract]
Net amortization of debt premiums and discounts and debt issuance costs	$ 10,740	$ 3,626	$ 3,420

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, 2016		17,794,477
Balance beginning at Dec. 31, 2016	$ 935,004	$ 178	$ 1,474,067	$ 96,329	$ 26,957	$ (662,527)
Increase (Decrease) in Shareholders' Equity
Issuance of shares, net (in shares)		6,976,757
Issuance of shares, net	493,866	$ 70	493,796
Share grants (in shares)		18,836
Share grants	$ 1,361		1,361
Share repurchases (in shares)	(3,590)	(3,591)
Share repurchases	$ (264)		(264)
Equity in unrealized loss of investees	9,428				9,428
Unrealized gain on equity securities	24,042				24,042
Amounts reclassified from cumulative other comprehensive income to net income	(34)
Net income (loss) available for common shareholders	11,815			11,815
Distributions to common shareholders	(145,209)					(145,209)
Balance ending (in shares) at Dec. 31, 2017		24,786,479
Balance ending at Dec. 31, 2017	1,330,043	$ 248	1,968,960	108,144	60,427	(807,736)
Increase (Decrease) in Shareholders' Equity
Issuance of shares, net (in shares)		23,281,738
Issuance of shares, net	639,783	$ 233	639,550
Share grants (in shares)		19,925
Share grants	$ 1,523		1,523
Share repurchases (in shares)	(4,984)
Shares forfeitures or repurchases (in shares)		(5,239)
Share forfeitures or repurchases	$ (232)		(232)
Equity in unrealized loss of investees	(40)				(40)
Amounts reclassified from cumulative other comprehensive income to net income	(37)
Net income (loss) available for common shareholders	(22,255)			(22,255)
Distributions to common shareholders	(170,566)					(170,566)
Balance ending (in shares) at Dec. 31, 2018		48,082,903
Balance ending at Dec. 31, 2018	1,778,968	$ 481	2,609,801	146,882	106	(978,302)
Increase (Decrease) in Shareholders' Equity
Share grants (in shares)		136,100
Share grants	$ 3,098	$ 1	3,097
Share repurchases (in shares)	(15,588)
Shares forfeitures or repurchases (in shares)		(17,062)
Share forfeitures or repurchases	$ (473)		(473)
Amounts reclassified from cumulative other comprehensive income to net income	(196)				(196)
Equity in unrealized gain of investees	90				90
Unrealized loss on financial instrument	(200)				(200)
Net income (loss) available for common shareholders	30,335			30,335
Distributions to common shareholders	(105,868)					(105,868)
Balance ending (in shares) at Dec. 31, 2019		48,201,941
Balance ending at Dec. 31, 2019	$ 1,705,754	$ 482	$ 2,612,425	$ 177,217	$ (200)	$ (1,084,170)

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income (loss)	$ 30,335	$ (21,884)	$ 12,090
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation	89,400	66,685	52,427
Net amortization of debt premiums, discounts and issuance costs	10,740	3,626	3,420
Amortization of acquired real estate leases	197,978	94,375	56,174
Amortization of deferred leasing costs	5,973	4,833	3,802
Gain on sale of real estate	(105,131)	(20,661)	0
Loss on impairment of real estate	22,255	8,630	9,490
Loss on early extinguishment of debt	769	709	1,715
Straight line rental income	(27,507)	(10,164)	(5,582)
Other non-cash expenses, net	2,011	250	300
Loss on equity securities, net	44,007	7,552	0
Increase in carrying value of property included in discontinued operations	0	0	(619)
Equity in net losses of investees	1,259	2,269	13
Distribution of earnings from Affiliates Insurance Company	2,438	0	0
Equity in earnings of Select Income REIT included in discontinued operations	0	(20,873)	(21,584)
Net gain on issuance of shares by Select Income REIT included in discontinued operations	0	(29)	(72)
Loss on sale of Select Income REIT shares included in discontinued operations	0	15,180	0
Distributions of earnings from Select Income REIT	0	20,873	21,584
Change in assets and liabilities:
Rents receivable	12,586	5,021	(4,990)
Deferred leasing costs	(27,971)	(9,203)	(5,017)
Other assets	3,266	1,127	1,368
Accounts payable and other liabilities	(19,333)	(3,303)	11,696
Due to related persons	(27,746)	(97)	1,339
Net cash provided by operating activities	215,329	144,916	137,554
CASH FLOWS FROM INVESTING ACTIVITIES:
Real estate acquisitions	(2,905)	25,221	(1,187,012)
Real estate improvements	(62,676)	(47,500)	(45,940)
Distributions in excess of earnings from Select Income REIT	0	17,251	29,248
Distributions in excess of earnings from unconsolidated joint ventures	2,370	3,751	482
Distributions in excess of earnings from Affiliates Insurance Company	6,562	0	0
Proceeds from sale of properties, net	829,794	304,808	15,083
Proceeds from sale of Select Income REIT shares	0	435,125	0
Proceeds from sale of The RMR Group Inc. common shares, net	104,674	0	0
Net cash provided by (used in) investing activities	877,819	738,656	(1,188,139)
CASH FLOWS FROM FINANCING ACTIVITIES:
Repayment of mortgage notes payable	(12,054)	(3,708)	(11,909)
Repayment of unsecured term loans	(388,000)	(162,000)	0
Repayment of senior unsecured notes	(350,000)	0	0
Proceeds from issuance of senior notes, after discounts	0	0	297,954
Proceeds from issuance of common shares, net	0	0	493,866
Borrowings on unsecured revolving credit facility	430,000	238,000	645,000
Repayments on unsecured revolving credit facility	(605,000)	(741,000)	(235,000)
Payment of debt issuance costs	0	(3,936)	(4,644)
Repurchase of common shares	(473)	(232)	(264)
Redemption of preferred units of limited partnership	0	(20,221)	0
Preferred units of limited partnership distributions	0	(646)	0
Distributions to common shareholders	(105,868)	(170,566)	(145,209)
Net cash (used in) provided by financing activities	(1,031,395)	(864,309)	1,039,794
Increase (decrease) in cash, cash equivalents and restricted cash	61,753	19,263	(10,791)
Cash, cash equivalents and restricted cash at beginning of period	38,943	19,680	30,471
Cash, cash equivalents and restricted cash at end of period	100,696	38,943	19,680
SUPPLEMENTAL CASH FLOW INFORMATION:
Interest paid	131,735	65,188	55,048
Income taxes paid	491	68	117
NON-CASH INVESTING ACTIVITIES:
Assumed working capital	0	25,170	(1,596)
Real estate and investment acquired by issuance of common shares	0	(639,809)	0
Real estate and investment acquired by assumption of debt	0	(1,719,772)	0
NON-CASH FINANCING ACTIVITIES:
Select Income REIT unsecured revolving credit facility	0	108,000	0
Assumption of mortgage notes payable	0	161,772	167,548
Assumption of senior unsecured notes	0	1,450,000	0
Preferred units of limited partnership issued	0	0	20,221
Issuance of common shares	$ 0	$ 639,809	$ 0

CONSOLIDATED STATEMENTS OF CA_2

CONSOLIDATED STATEMENTS OF CASH FLOWS - SUPPLEMENTAL DISCLOSURE OF CASH, CASH EQUIVALENTS AND RESTRICTED CASH - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of Cash Flows [Abstract]
Cash and cash equivalents	$ 93,744	$ 35,349	$ 16,569
Restricted Cash	6,952	3,594	3,111
Total cash, cash equivalents and restricted cash shown in the statements of cash flows	$ 100,696	$ 38,943	$ 19,680

Organization

Organization	12 Months Ended
	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization	Organization Office 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, 2019 , our wholly owned properties were comprised of 189 properties located in 35 states and the District of Columbia containing approximately 25.7 million rentable square feet and we had a noncontrolling ownership interest in three properties totaling approximately 0.4 million rentable square feet through two unconsolidated joint ventures in which we own 51% and 50% interests. Merger with Select Income REIT On December 31, 2018, we completed our acquisition of Select Income REIT, or SIR, a REIT that owned properties primarily net leased to single tenants, pursuant to a merger transaction, or the SIR Merger. As a result of the SIR Merger, we acquired SIR’s property portfolio of 99 properties with approximately 16.5 million rentable square feet. The aggregate transaction value, based on the closing price of our common shares on December 31, 2018 of $6.87 per share (prior to the Reverse Share Split, as defined below), was approximately $2,409,740 , excluding closing costs of approximately $27,497 ( $14,508 of which was paid by us and $12,989 of which was paid by SIR) and including the repayment or assumption of approximately $1,719,772 of SIR debt. In connection with the SIR Merger, SIR shareholders received 1.04 of our newly issued common shares for each common share of SIR, with cash paid in lieu of fractional shares. As a condition of the SIR Merger, on October 9, 2018, we sold all of the 24,918,421 common shares of SIR we then owned, or the Secondary Sale, in an underwritten public offering at a price of $18.25 per share, raising net proceeds of $435,125 after deducting underwriting discounts and offering expenses. We used the net proceeds from the Secondary Sale to repay amounts then outstanding under our revolving credit facility. In addition, as a condition of the SIR Merger, on December 27, 2018, SIR paid a pro rata distribution to SIR’s shareholders of record as of the close of business on December 20, 2018 of all 45,000,000 common shares of beneficial interest of Industrial Logistics Properties Trust, or ILPT, that SIR owned, or the ILPT Distribution. The SIR Merger and the other transactions in connection with the SIR Merger, including the Secondary Sale and the ILPT Distribution, are collectively referred to herein as the SIR Transactions. Following completion of the SIR Merger and the other SIR Transactions, on December 31, 2018, we effected a reverse share split of our common shares, or the Reverse Share Split, pursuant to which every four of our common shares issued and outstanding as of the effective time of the Reverse Share Split were converted and reclassified into one of our common shares. All impacted amounts and share information included in the consolidated financial statements and notes hereto for the periods presented prior to January 1, 2019 have been retroactively adjusted for the Reverse Share Split as if the Reverse Share Split occurred on the first day of the first period presented.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2019
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, building 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 $2,710 , $2,903 and $2,764 during the years ended December 31, 2019 , 2018 and 2017 , 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 $195,268 , $91,472 and $53,410 during the years ended December 31, 2019 , 2018 and 2017 , 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, 2019 and 2018 , our acquired real estate leases and assumed real estate obligations, excluding properties classified as held for sale, were as follows: December 31, 2019 2018 Acquired real estate leases: Capitalized above market lease values $ 61,971 $ 62,260 Less: accumulated amortization (29,927 ) (20,956 ) Capitalized above market lease values, net 32,044 41,304 Lease origination value 1,032,769 1,168,979 Less: accumulated amortization (332,431 ) (153,725 ) Lease origination value, net 700,338 1,015,254 Acquired real estate leases, net $ 732,382 $ 1,056,558 Assumed real estate lease obligations: Capitalized below market lease values $ 28,118 $ 31,091 Less: accumulated amortization (14,943 ) (11,060 ) Assumed real estate lease obligations, net $ 13,175 $ 20,031 As of December 31, 2019 , the weighted average amortization periods for capitalized above market leases, lease origination value and capitalized below market lease values were 4.7 years, 6.2 years and 5.8 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, 2019 are estimated to be $162,586 in 2020 , $135,002 in 2021 , $118,465 in 2022 , $97,087 in 2023 , $71,836 in 2024 and $134,231 thereafter. We regularly evaluate whether events or changes in circumstances have occurred that could indicate an impairment in the value of long lived assets. 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 lives of our long lived assets. If we change our estimate of the remaining lives, we allocate the carrying value of the affected assets over their revised remaining 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, inducements and, until January 1, 2019, legal fees associated with our entering leases. We amortize those costs, which are included in depreciation and amortization expense, on a straight line basis over the terms of the respective leases. Effective January 1, 2019, in accordance with Financial Accounting Standards Board, or FASB, Accounting Standards Update, or ASU, No. 2016-02, Leases , legal costs associated with the execution of our leases, which were previously capitalized and amortized over the life of their respective leases, are expensed as incurred and included in general and administrative expenses in our consolidated statements of comprehensive income (loss). Deferred leasing costs, excluding properties classified as held for sale, totaled $55,716 and $38,840 at December 31, 2019 and 2018 , respectively, and accumulated amortization of deferred leasing costs totaled $15,609 and $13,168 at December 31, 2019 and 2018 , respectively. Future amortization of deferred leasing costs to be recognized during the current terms of our existing leases as of December 31, 2019 are estimated to be $5,949 in 2020 , $5,419 in 2021 , $4,591 in 2022 , $3,973 in 2023 , $3,536 in 2024 and $16,639 thereafter. Debt Issuance Costs . Debt issuance costs include capitalized issuance or assumption costs related to borrowings, which are 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, 2019 and 2018 , debt issuance costs for our revolving credit facility were $4,125 and accumulated amortization of debt issuance costs for our revolving credit facility were $1,059 and $49 , respectively. Debt issuance costs, net of accumulated amortization, for our former term loans, 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, 2019 and 2018 , debt issuance costs, net of accumulated amortization, for our former term loans, senior unsecured notes and mortgage notes payable totaled $10,631 and $12,888 , respectively. Future amortization of debt issuance costs to be recognized with respect to our revolving credit facility, senior unsecured notes and mortgage notes as of December 31, 2019 are estimated to be $1,948 in 2020 , $1,934 in 2021 , $1,703 in 2022 , $407 in 2023 , $344 in 2024 and $7,361 thereafter. Mortgage Notes Receivable. In connection with a property we sold in July 2016, we provided $3,600 of mortgage financing to the buyer. The mortgage note requires interest to be paid at an annual rate of LIBOR plus 4.0% , subject to a minimum annual interest rate of 5.0% , and requires monthly payments of interest only until maturity on June 30, 2021. The mortgage note receivable of $3,600 is included in other assets in our consolidated balance sheets at December 31, 2019 and 2018. Equity Securities. We previously owned 2,801,060 common shares of class A common stock of The RMR Group Inc., or RMR Inc., including 1,586,836 common shares acquired from SIR on December 31, 2018 in connection with the SIR Merger, that we sold on July 1, 2019 for net proceeds of $104,674 , after deducting underwriting discounts and commissions and other offering expenses. Prior to the sale of our shares of RMR Inc. class A common stock on July 1, 2019, our equity securities were recorded at fair value based on their quoted market price at the end of each reporting period. Effective January 1, 2018, changes in the fair value of our equity securities were recorded through earnings in accordance with ASU No. 2016-01, Recognition and Measurement of Financial Assets and Financial Liabilities . Prior to January 1, 2018, unrealized gains and losses on equity securities were recorded as a component of cumulative comprehensive income (loss) in shareholders’ equity. See Note 5 for more information regarding the sale of our RMR Inc. class A common stock. Equity Method Investments. We account for our investments in Affiliates Insurance Company, or AIC, until AIC was dissolved as described in Note 5, and SIR, until we sold the SIR common shares we owned as described in Note 1, using the equity method of accounting. Significant influence was present through common representation on the boards of trustees or directors of us, AIC, until February 13, 2020, and, SIR, until December 31, 2018. See Notes 5, 10 and 11 for more information of our investments in AIC and SIR. We also own 51% and 50% interests in two unconsolidated joint ventures which own three properties. The properties owned by these joint ventures are encumbered by an aggregate $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 investment in these joint ventures under the equity method of accounting. See Note 3 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 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, 2019 , 2018 and 2017 . These amounts are included in the net business management and property management fee amounts for such periods. As of December 31, 2019 , the remaining unamortized amount of this liability was $17,406 . Future amortization of this liability as of December 31, 2019 is estimated to be $1,087 in 2020 through 2024 and $11,971 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. In February 2016, FASB issued ASU No. 2016-02, Leases . In July 2018, the FASB issued ASU No. 2018-10, Codification Improvements to Topic 842, Leases and ASU No. 2018-11, Leases (Topic 842): Targeted Improvements . In December 2018, the FASB issued ASU No. 2018-20 Leases (Topic 842), Narrow-Scope Improvements for Lessors . Collectively, these standards set out the principles for the recognition, measurement, presentation and disclosure of leases for both parties to a contract (i.e., lessees and lessors). ASU No. 2016-02 requires lessees to apply a dual approach, classifying leases as either finance or operating leases based on the principle of whether or not the lease is effectively a financed purchase of the leased asset by the lessee. This classification will determine whether the lease expense is recognized based on an effective interest method or on a straight line basis over the term of the lease. ASU No. 2016-02 requires lessors to account for leases using an approach that is substantially equivalent to existing guidance for sales type leases, direct financing leases and operating leases. These standards were effective as of January 1, 2019. Upon adoption, we applied the package of practical expedients that has allowed us to not reassess (i) whether any expired or existing contracts are or contain leases, (ii) lease classification for any expired or existing leases and (iii) initial direct costs for any expired or existing leases. Furthermore, we applied the optional transition method in ASU No. 2018-11, which has allowed us to initially apply the new leases standard at the adoption date and recognize a cumulative effect adjustment to the opening balance of retained earnings in the adoption period, although we did not have an adjustment. Additionally, our leases met the criteria in ASU No. 2018-11 to not separate non-lease components from the related lease component; therefore, the accounting for these leases remained largely unchanged from the previous standard. The adoption of ASU No. 2016-02 and the related improvements did not have a material impact in our consolidated financial statements. Upon adoption, (i) allowances for bad debts are now recognized as a direct reduction of rental income, and (ii) legal costs associated with the execution of our leases, which were previously capitalized and amortized over the life of their respective leases, are expensed as incurred. Subsequent to January 1, 2019, provisions for credit losses are now included in rental income in our consolidated statements of comprehensive income (loss). Provisions for credit losses prior to January 1, 2019 were previously included in other operating expenses in our consolidated financial statements and prior periods are not reclassified to conform to the current presentation. 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. We increased rental income by $27,507 , $10,164 and $5,582 to record revenue on a straight line basis during the years ended December 31, 2019 , 2018 and 2017 , respectively. Rents receivable, excluding properties classified as held for sale, include $54,837 and $34,006 of straight line rent receivables at December 31, 2019 and 2018 , 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 $91,076 , $45,261 and $30,998 for the years ended December 31, 2019 , 2018 and 2017, respectively, of which tenant reimbursements totaled $86,353 , $40,764 and $27,146 , respectively. 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 determined that all of our leases qualify for the practical expedient 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. The following operating lease maturity analysis presents the future contractual lease payments to be received by us through 2039 as of December 31, 2019 : Year Amount 2020 $ 489,420 2021 466,210 2022 428,149 2023 381,164 2024 313,456 Thereafter 1,052,669 Total $ 3,131,068 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, 2019 , tenants who currently represent approximately 6.7% of our total operating lease maturities have currently exercisable rights to terminate their leases before the stated terms of their leases expire. In 2020 , 2021 , 2022 , 2023 , 2024 , 2025 , 2026 , 2027 , 2028 , 2030 and 2034 , early termination rights become exercisable by other tenants who currently represent an additional approximately 4.8% , 1.6% , 2.7% , 1.1% , 2.0% , 5.2% , 2.6% , 1.1% , 2.6% , 0.8% and 0.2% of our total operating lease maturities, respectively. In addition, as of December 31, 2019 , 13 of our tenants have 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 13 tenants represent approximately 6.4% of our total operating lease maturities as of December 31, 2019 . Right of use asset and lease liability. In connection with our acquisition of First Potomac Realty Trust, or FPO, in 2017, we assumed the lease for FPO’s former corporate headquarters, which expires on January 31, 2021. We sublease a portion of the space, which sublease expires on January 31, 2021. For leases where we are the lessee, we are required to record a right of use asset and lease liability for all leases with a term greater than 12 months. The value of the right of use asset and related liability representing our future obligation under the lease arrangement for which we are the lessee were $2,149 and $2,179 , respectively, as of December 31, 2019 . The right of use asset and related lease liability are included within other assets, net and accounts payable and other liabilities, respectively, within our consolidated balance sheets. Rent expense incurred under the lease, net of sublease revenue, was $1,670 , $1,707 and $374 for the years ended December 31, 2019 , 2018 and 2017, respectively. As of December 31, 2019 , our lease provides for contractual minimum rent payments to a third party during the remaining lease term as summarized below: Year Contractual Minimum Rent Payments 2020 $ 2,049 2021 175 Total lease payments 2,224 Less: imputed interest (45 ) Present value of lease liabilities $ 2,179 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 equity method investees and, prior to the adoption of ASU No. 2016-01 on January 1, 2018, unrealized gains and losses related to our former investment in RMR Inc. See Notes 3 and 5 for more information regarding these investments. Per Common Share Amounts. We calculate basic earnings per common share by dividing net income (loss) available for common shareholders by the weighted average number of our common shares of beneficial ownership, $.01 par value, or our common shares, outstanding during the period. 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 and the related impact on earnings, are considered when calculating diluted earnings per share. For the years ended December 31, 2019, 2018 and 2017, 12 , four and five unvested common shares, respectively, were not included in the calculation of diluted earnings per share because to do so would have been antidilutive. 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. Reclassifications. Reclassifications have been made to the prior years’ consolidated financial statements to conform to the current year’s presentation. Segment Reporting. We operate in one business segment: direct ownership of real estate properties. New Accounting Pronouncements. In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments , which requires that entities use a new forward looking “expected loss” model that generally will result in the earlier recognition of allowance for credit losses. The measurement of expected credit losses is based upon historical experience, current conditions, and reasonable and supportable forecasts that affect the collectability of the reported amount. ASU No. 2016-13 is effective as of January 1, 2020. We adopted this standard using the modified retrospective approach. The implementation of this standard did not have a material impact in our consolidated financial statements.

Real Estate Properties

Real Estate Properties	12 Months Ended
	Dec. 31, 2019
Real Estate [Abstract]
Real Estate Properties	Real Estate Properties As of December 31, 2019 , our wholly owned properties were comprised of 189 properties with approximately 25.7 million rentable square feet, with an aggregate undepreciated carrying value of $3,555,131 , including $61,900 classified as held for sale, and we had a noncontrolling ownership interest in three properties totaling approximately 0.4 million rentable square feet through two unconsolidated joint ventures in which we own 51% and 50% interests. 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 2020 and 2039. 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, 2019 , we entered into 107 leases for 2.9 million rentable square feet for a weighted (by rentable square feet) average lease term of 8.6 years and we made commitments for approximately $77,541 of leasing related costs. As of December 31, 2019 , we have estimated unspent leasing related obligations of $55,984 . Merger with Select Income REIT As described in Note 1, on December 31, 2018, we completed the SIR Merger, pursuant to which we acquired SIR’s property portfolio of 99 properties with approximately 16.5 million rentable square feet. The total consideration transferred and assumed debt for the SIR Merger was $2,409,740 , including the assumption of $1,719,772 of debt and excluding acquisition related costs. The following table summarizes the consideration transferred and liabilities assumed: Total Purchase Price (excluding acquisition costs): OPI common shares issued 23,282,704 Closing price of OPI common shares on December 31, 2018 $ 27.48 Value of consideration transferred $ 639,809 Cash consideration for fractional shares 8 Equity issuance costs (239 ) Value of consideration transferred 639,578 Assumed working capital 50,390 Assumed senior unsecured notes, principal balance 1,450,000 Assumed mortgage notes payable, principal balance 161,772 Select Income REIT unsecured revolving credit facility repaid at closing 108,000 Non-cash portion of purchase price 1,770,162 Total consideration transferred and liabilities assumed $ 2,409,740 As of December 31, 2019, we finalized the purchase price allocation for the SIR Merger from the preliminary amounts reported as of December 31, 2018. The adjustments made during the year ended December 31, 2019 to the fair value of acquired assets and liabilities assumed did not have a significant impact on our consolidated balance sheets or our consolidated statements of comprehensive income (loss). The following table summarizes the purchase price allocation for SIR based on estimated fair values as of the December 31, 2018: Purchase Price Allocation: Land $ 477,977 Buildings and improvements 956,801 Assets of properties held for sale 6,846 Acquired real estate leases 854,431 Cash 24,744 Restricted cash 476 Rents receivable 11,370 Other assets (1) 88,658 Total assets 2,421,303 Unsecured revolving credit facility (2) (108,000 ) Senior unsecured notes (3) (1,410,947 ) Mortgage notes payable (4) (159,490 ) Accounts payable and other liabilities (61,289 ) Assumed real estate lease obligations (11,879 ) Due to related persons (30,120 ) Net assets acquired 639,578 Assumed working capital 50,390 Select Income REIT unsecured revolving credit facility repaid at closing (2) 108,000 Assumed senior unsecured notes, principal balance 1,450,000 Assumed mortgage notes payable, principal balance 161,772 Consideration transferred and liabilities assumed (5) $ 2,409,740 (1) Other assets include $84,229 for SIR’s investment in shares of class A common stock of RMR Inc. which was recorded at fair value as of December 31, 2018. (2) We repaid the outstanding balance under SIR’s revolving credit facility at the closing of the SIR Merger with borrowings under our revolving credit facility. (3) The aggregate principal balance of the senior unsecured notes was $1,450,000 as of December 31, 2018. (4) The aggregate principal balance of the mortgage notes payable was $161,772 as of December 31, 2018. (5) Purchase price excludes acquisition related costs. We were the accounting acquirer of SIR and accounted for the SIR Merger as a business combination because substantially all of the fair value of the gross assets acquired was not concentrated in a single identifiable asset or a group of similar identifiable assets and we acquired inputs and a substantive process that together significantly contributed to the ability to create outputs. Although we have and SIR had no employees, the personnel and various services required to operate our and SIR’s businesses are and were provided pursuant to business and property management agreements with RMR LLC. These agreements were in effect before, and, in our case, remain in effect after, the SIR Merger. As a result, our acquisition of SIR included a substantive process for accounting purposes. The assets acquired and liabilities assumed were recorded at their respective fair values and added to our consolidated balance sheet as of December 31, 2018. We allocated the purchase price based on the estimated fair values of the acquired assets and liabilities assumed in a manner consistent with our purchase price allocation accounting policy described in Note 2. We engaged an independent real estate consulting firm to assist us with determining the purchase price allocations and to provide market information and evaluations which are relevant to purchase price allocations and determinations of useful lives. As of the date acquired, the weighted average amortization periods for capitalized above market lease values, lease origination value and capitalized below market lease values were 5.8 years, 7.2 years and 5.7 years, respectively. FPO Transaction On October 2, 2017, we completed our acquisition of FPO, as a result of which we acquired 72 properties with 6.0 million rentable square feet, and FPO’s 51% and 50% interests in two joint ventures that own three properties with 0.4 million rentable square feet, or collectively, the FPO Transaction. The aggregate value we paid for FPO was $1,370,888 , including $651,696 in cash to FPO’s shareholders, the repayment of $483,000 of FPO debt and the assumption of $167,548 of mortgage debt; this amount excludes the $82,000 of mortgage debt that encumber the three properties owned by the two joint ventures and the payment of certain transaction fees and expenses, net of FPO cash on hand. We financed the cash payments for the FPO Transaction with borrowings under our revolving credit facility and with cash on hand, including net proceeds from our public offerings of common shares and senior unsecured notes. We accounted for the FPO Transaction as an asset acquisition. Our allocation of the purchase price was based on estimates of the relative fair value of the acquired assets and assumed liabilities. The following table summarizes the total consideration paid and the estimated fair values of the assets acquired and liabilities assumed in the FPO Transaction: Total Purchase Price: Cash consideration $ 1,175,140 Acquisition related costs 9,575 Total cash consideration 1,184,715 Preferred units of limited partnership issued (1) 20,221 Acquired net working capital (1,596 ) Assumed mortgage notes 167,548 Non-cash portion of purchase price 186,173 Gross purchase price $ 1,370,888 Purchase Price Allocation: Land $ 360,909 Buildings and improvements 681,340 Acquired real estate leases (2) 283,498 Investment in unconsolidated joint ventures 51,305 Cash 11,191 Restricted cash 1,018 Rents receivable 2,672 Other assets 3,640 Total assets 1,395,573 Mortgage notes payable (3) (167,936 ) Assumed real estate lease obligations (2) (5,776 ) Accounts payable and accrued expenses (10,640 ) Rents collected in advance (1,436 ) Security deposits (4,849 ) Net assets acquired 1,204,936 Assumed working capital (1,596 ) Assumed principal balance of debt 167,548 Gross purchase price $ 1,370,888 (1) Pursuant to the terms of the FPO Transaction, each unit of limited partnership interest in FPO’s operating partnership that was not liquidated on the closing date was exchanged on a one-for-one basis for 5.5% Series A Cumulative Preferred Units of the surviving subsidiary. As of December 31, 2017, the carrying value of these Series A Cumulative Preferred Units was $20,496 and was recorded as temporary equity on our consolidated balance sheet. On May 1, 2018, we redeemed all 1,813,504 of the outstanding 5.5% Series A Cumulative Preferred Units for $11.15 per unit (plus accrued and unpaid distributions) for an aggregate of $20,310 . (2) As of the date acquired, the weighted average amortization periods for capitalized above market lease values, lease origination value and capitalized below market lease values were 3.2 years , 3.1 years and 3.8 years , respectively. (3) Includes fair value adjustments totaling $388 on $167,936 principal amount of mortgage notes we assumed in connection with the FPO Transaction. Pro Forma Information (Unaudited) The following table presents our pro forma results of operations for the year ended December 31, 2018 as if the SIR Transactions and related financing activities, had occurred on January 1, 2018. The SIR results of operations included in this pro forma financial information have been adjusted to remove ILPT’s results of operations for the year ended December 31, 2018. The effect of these adjustments was to decrease pro forma rental income and pro forma net income by $152,735 and $46,237 , respectively, for the year ended December 31, 2018. This pro forma financial information is not necessarily indicative of what our actual financial position or results of operations would have been for the period presented or for any future period. Differences could result from numerous factors, including future changes in our portfolio of investments, capital structure, property level operating expenses and revenues, including rents expected to be received on our existing leases, leases we entered since December 31, 2018, or leases we may enter in the future, changes in interest rates and other reasons. Actual future results are likely to be different from amounts presented in this pro forma financial information and such differences could be significant. Year Ended December 31, 2018 Rental income $ 758,596 Net loss $ (87,240 ) Net loss per common share $ (1.82 ) During the year ended December 31, 2018, we did not recognize any revenue or operating income from the assets acquired and liabilities assumed in the SIR Merger. 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, 2019 and 2018 , our investment in unconsolidated joint ventures consisted of the following: OPI Ownership OPI Carrying Value of Investment at December 31, Number of Properties Location Square Feet Joint Venture 2019 2018 Prosperity Metro Plaza 51% $ 22,483 $ 23,969 2 Fairfax, VA 328,456 1750 H Street, NW 50% 17,273 19,696 1 Washington, D.C. 115,411 Total $ 39,756 $ 43,665 3 443,867 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, 2019 and 2018 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. At December 31, 2019 , the aggregate unamortized basis difference of our two unconsolidated joint ventures of $7,951 is primarily attributable to the difference between the amount for which we purchased our interest in the joint ventures, including transaction costs, and the historical carrying value of the net assets of the joint ventures. This difference will be amortized over the remaining useful life of the related properties and included in the reported amount of equity in net earnings (losses) of investees. 2019 Disposition Activities During the year ended December 31, 2019, we sold 58 properties with a combined 6.2 million rentable square feet for an aggregate sales price of $ 848,853 , excluding closing costs. The sales of these properties, as presented in the following table (except for the March 2019 sale), do not represent significant dispositions individually or in the aggregate nor do they represent a strategic shift. 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). Date of Sale Number of Properties Location Square Feet Gross Sale Price (1) Gain (Loss) on Sale of Real Estate Loss on Impairment of Real Estate February 2019 34 Northern Virginia and Maryland 1,635,868 $ 198,500 $ — $ 732 March 2019 1 Washington, D.C. 129,035 70,000 22,075 — May 2019 1 Buffalo, NY 121,711 16,900 — 5,137 May 2019 1 Maynard, MA 287,037 5,000 (227 ) — June 2019 1 Kapolei, HI 416,956 7,100 — — July 2019 1 San Jose, CA 71,750 14,000 (270 ) — July 2019 1 Nashua, NH 321,800 25,000 8,401 — August 2019 1 Arlington, TX 182,630 14,900 187 — August 2019 1 Rochester, NY 94,800 4,765 (104 ) — August 2019 1 Hanover, PA 502,300 5,500 (417 ) — August 2019 1 San Antonio, TX 618,017 198,000 3,869 — September 2019 1 Topeka, KS 143,934 15,600 36 — September 2019 1 Falling Waters, WV 40,348 650 — 2,179 September 2019 1 San Diego, CA 43,918 8,950 3,062 — October 2019 3 Columbia, SC 180,703 10,750 — 3,581 November 2019 3 Metro DC - MD 372,605 61,938 1,177 — December 2019 1 San Diego, CA 148,488 23,750 6,823 — December 2019 1 Phoenix, AZ 122,646 12,850 860 — December 2019 1 Houston, TX 497,477 130,000 59,992 — December 2019 1 Kansas City, KS 170,817 11,700 — 1,172 December 2019 1 San Jose, CA 75,621 13,000 (333 ) — 58 6,178,461 $ 848,853 $ 105,131 $ 12,801 (1) Gross sale price is the gross contract price, includes purchase price adjustments, if any, and excludes closing costs. As of December 31, 2019, we had six properties with an aggregate undepreciated carrying value of $61,900 under agreements to sell, as presented in the following table. We have classified these properties as held for sale in our consolidated balance sheet at December 31, 2019. Date of Sale Agreement Number of Properties Location Square Feet Gross Sale Price (1) October 2019 (2) 2 Stafford, VA 64,656 $ 14,063 October 2019 1 Fairfax, VA 83,130 22,200 October 2019 (2) 1 Windsor, CT 97,256 7,000 November 2019 (3) 1 Trenton, NJ 267,025 30,100 November 2019 1 Lincolnshire, IL 222,717 12,000 6 734,784 $ 85,363 (1) Gross sale price is the gross contract price, includes purchase price adjustments, if any, and excludes closing costs. (2) The sale of these properties was completed in January 2020. (3) We recorded a $9,454 loss on impairment of real estate during the year ended December 31, 2019 to adjust the carrying value of this property to its estimated fair value less costs to sell. 2018 Disposition Activities During the year ended December 31, 2018, we sold 19 properties with a combined 2.2 million rentable square feet for an aggregate purchase price of $320,255 , excluding closing costs. The sales of these properties, as presented in the following table, do not represent significant dispositions individually or in the aggregate nor do they represent a strategic shift. 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). Date of Sale Number of Properties Location Square Feet Gross Sale Price (1) Gain on Sale of Real Estate Loss on Impairment of Real Estate March 2018 1 Minneapolis, MN 193,594 $ 20,000 $ — $ 640 May 2018 1 New York, NY 187,060 118,500 17,249 — May 2018 1 Sacramento, CA 110,500 10,755 — 3,029 November 2018 1 Golden, CO 43,231 4,000 54 — December 2018 15 Southern Virginia 1,640,252 167,000 3,358 — 19 2,174,637 $ 320,255 $ 20,661 $ 3,669 (1) Gross sale price is the gross contract price, includes purchase price adjustments, if any, and excludes closing costs. In February 2018, we entered an agreement to sell an office property located in Safford, AZ with 36,139 rentable square feet for $8,250 . We recorded a $2,453 loss on impairment of real estate to reduce the carrying value of the property to its estimated fair value less costs to sell in the three months ended March 31, 2018. In April 2018, the buyer terminated the sale agreement and we removed this property from held for sale status. We recorded a $322 adjustment to impairment of real estate to increase the carrying value of the property to its estimated fair value during the year ended December 31, 2018. During the year ended December 31, 2018, we also recorded a $2,830 loss on impairment of real estate to reduce the carrying value of a portfolio of 34 properties, which was classified as held for sale as of December 31, 2018, to its estimated fair value less costs to sell. 2017 Disposition Activities - Continuing Operations In October 2017, we sold one vacant office property located in Albuquerque, NM with 29,045 rentable square feet and a net book value of $1,885 as of the date of sale, for $2,000 , excluding closing costs. During the year ended December 31, 2017 , we recorded a $230 loss on impairment of real estate to reduce the carrying value of this property to its estimated fair value. 2017 Disposition Activities – Discontinued Operations In August 2017, we sold one vacant office property in Falls Church, VA with 0.2 million rentable square feet and a net book value of $12,901 as of the date of sale for $13,523 , excluding closing costs. Results of operations for this property, which qualified as held for sale prior to our adoption in 2014 of ASU No. 2014-8, Reporting Discontinued Operations and Disclosures of Disposals of Components of an Entity , are classified as discontinued operations in our consolidated financial statements. During the year ended December 31, 2017 , we recorded an adjustment of $619 to increase the carrying value of this property to its estimated fair value less costs to sell. Summarized income statement information for this property is as follows: Statements of Income (Loss) Year Ended December 31, 2017 Rental income $ 17 Real estate taxes (88 ) Utility expenses (97 ) Other operating expenses (202 ) General and administrative (76 ) Increase in carrying value of property included in discontinued operations 619 Income from discontinued operations $ 173 2019 and 2020 Acquisition Activities In November 2019, we acquired a land parcel for $2,900 , excluding acquisition related costs, and in January 2020, we entered into an agreement to acquire a property for $11,500 , excluding acquisition related costs, both of which are adjacent to a property we own in Boston, MA. Other 2017 Acquisition Activities During the year ended December 31, 2017 , we acquired one property located in Manassas, VA with 0.1 million rentable square feet. This property was 100% leased to Prince William County on the date of acquisition. This transaction was accounted for as an asset acquisition. The purchase price was $12,657 , including capitalized acquisition costs of $37 . Our allocation of the purchase price of this acquisition is based on the relative estimated fair value of the acquired assets and assumed liabilities is presented in the following table. Acquisition Date Location Number of Properties Square Feet Purchase Price Land Building and Improvements Other Assumed Assets Jan 2017 Manassas, VA 1 69,374 $ 12,657 $ 1,562 $ 8,253 $ 2,842 In September 2017, we acquired transferable development rights that allow us to expand a property we own in Washington, D.C. for a purchase price of $2,030 , excluding acquisition costs.

Business and Property Managemen

Business and Property Management Agreements with RMR LLC	12 Months Ended
	Dec. 31, 2019
Related Party Transactions [Abstract]
Business and Property Management Agreements with RMR LLC	Business and Property Management Agreements with RMR LLC 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 LLC. We have two agreements with RMR LLC 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. Prior to the consummation of the SIR Merger, SIR had similar business and property management agreements with RMR LLC on substantially similar terms, which agreements were terminated in connection with the SIR Merger. See Notes 1 and 5 for more information regarding our relationship, agreements and transactions with SIR and RMR LLC. Management Agreements with RMR LLC . Our management agreements with RMR LLC 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 LLC 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 LLC 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; provided, however, our prior ownership of SIR common shares was not included as part of our real estate investments for purposes of calculating our base management fee due to RMR LLC since SIR paid separate business management fees to RMR LLC. • Incentive Management Fee . The incentive management fee which may be earned by RMR LLC 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 year measurement period, and • 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. Effective as of January 1, 2019, we amended our business management agreement with RMR LLC so that the SNL U.S. Office REIT Index will be used for periods beginning on and after January 1, 2019, with the SNL U.S. REIT Equity Index for periods ending on or prior to December 31, 2018. 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 additional common shares are issued or if we repurchase our common shares 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 periods ending with the year for which the incentive management fee is being calculated. • 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 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. • 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 LLC 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 LLC 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 LLC, we recognized net business management fees of $21,320 , $16,381 and $12,464 for the years ended December 31, 2019, 2018 and 2017, 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, 2019, 2018 and 2017 reflect a reduction of $603 , for the amortization of the liability we recorded in connection with our investment in RMR Inc., as further described in Note 2. No incentive management fee was payable to RMR LLC under our business management agreement for the years ended December 31, 2019, 2018 or 2017. • Property Management and Construction Supervision Fees . The property management fees payable to RMR LLC by us for each applicable period are equal to 3.0% of gross collected rents and the construction supervision fees payable to RMR LLC by us for each applicable period are equal to 5.0% of construction costs. Pursuant to our property management agreement with RMR LLC, we recognized aggregate net property management and construction supervision fees of $21,911 , $13,989 and $11,566 for each of the years ended December 31, 2019, 2018 and 2017, respectively. The net property management and construction supervision fees we recognized for the years ended December 31, 2019, 2018 and 2017 reflect a reduction of $484 for each of those years for the amortization of the liability we recorded in connection with our investment in RMR Inc., as further described in Note 2. These amounts are included in other operating expenses or have been capitalized, as appropriate, in our consolidated financial statements. In January 2019, we paid RMR LLC $2,185 for SIR’s 2018 business management, property management and construction supervision fees that it had accrued, but not paid, as of December 31, 2018. We also paid RMR LLC a business management incentive fee of $25,817 , which represented the incentive fee incurred, but not paid, by SIR for the year ended December 31, 2018. We had assumed the obligation to pay these amounts as a result of the SIR Merger. • Expense Reimbursement . We are generally responsible for all of our operating expenses, including certain expenses incurred or arranged by RMR LLC on our behalf. We are generally not responsible for payment of RMR LLC’s employment, office or administrative expenses incurred to provide management services to us, except for the employment and related expenses of RMR LLC’s employees assigned to work exclusively or partly at our properties, our share of the wages, benefits and other related costs of RMR LLC’s centralized accounting personnel, our share of RMR LLC’s costs for providing our internal audit function and as otherwise agreed. Our Audit Committee appoints our Director of Internal Audit and our Compensation Committee approves the costs of our internal audit function. Our property level operating expenses are generally incorporated into rents charged to our tenants, including certain payroll and related costs incurred by RMR LLC. We reimbursed RMR LLC $26,442 , $21,279 and $15,321 for these expenses and costs for each of the years ended December 31, 2019, 2018 and 2017, respectively. We included these amounts in other operating expenses and general and administrative expense, as applicable, for these periods. We assumed the obligation to reimburse RMR LLC for similar expenses and costs that RMR LLC had incurred on behalf of SIR in the ordinary course but which SIR had not paid as of December 31, 2018. We reimbursed RMR LLC $462 in January 2019 for these SIR expenses and costs. • Term . Our management agreements with RMR LLC have terms that end on December 31, 2039, 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 LLC: (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 LLC, as defined therein. RMR LLC 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 LLC for convenience, or if RMR LLC terminates one or both of our management agreements for good reason, we have agreed to pay RMR LLC 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 LLC for a performance reason, we have agreed to pay RMR LLC 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 LLC for cause or as a result of a change of control of RMR LLC. • Transition Services . RMR LLC has agreed to provide certain transition services to us for 120 days following an applicable termination by us or notice of termination by RMR LLC, 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 LLC, RMR LLC 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 LLC and other companies to which RMR LLC 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 LLC, we acknowledge that RMR LLC 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 LLC.

Related Person Transactions

Related Person Transactions	12 Months Ended
	Dec. 31, 2019
Related Party Transactions [Abstract]
Related Person Transactions	Related Person Transactions We have relationships and historical and continuing transactions with SIR (prior to the SIR Merger), RMR LLC, RMR Inc. and others related to them, including other companies to which RMR LLC or its subsidiaries provide management services and some of which have trustees, directors or officers who are also our Trustees or officers. RMR Inc. is the managing member of RMR LLC. The Chair of our Board of Trustees and one of our Managing Trustees, Adam D. Portnoy, as the sole trustee of ABP Trust, is the controlling shareholder of RMR Inc. and is a managing director and the president and chief executive officer of RMR Inc. and an officer and employee of RMR LLC. David M. Blackman, our other Managing Trustee and our President and Chief Executive Officer, also serves as an officer and employee of RMR LLC, and each of our other officers, is also an officer and employee of RMR LLC. Some of our Independent Trustees also serve as independent directors or independent trustees of other public companies to which RMR LLC or its subsidiaries provide management services, including SIR (until it ceased to exist). Adam Portnoy serves as chair of the boards of trustees or boards of directors of several of these public companies and as a managing director or managing trustee of these companies and other officers of RMR LLC serve as managing trustees or managing directors of certain of these companies. In addition, officers of RMR LLC and RMR Inc. serve as our officers and officers of other companies to which RMR LLC or its subsidiaries provide management services. Our Manager, RMR LLC . We have two agreements with RMR LLC to provide management services to us. See Note 4 for more information regarding our management agreements with RMR LLC. Leases with RMR LLC . We lease office space to RMR LLC in certain of our properties for RMR LLC’s property management offices. Pursuant to our lease agreements with RMR LLC, we recognized rental income from RMR LLC for leased office space of $1,142 , $1,026 and $303 for the years ended December 31, 2019, 2018 and 2017, respectively. Our office space leases with RMR LLC are terminable by RMR LLC if our management agreements with RMR LLC are terminated. Share Awards to RMR LLC Employees . As described further in Note 9, we award shares to our officers and other employees of RMR LLC annually. Generally, one fifth of these awards vest on the grant date and one fifth vests on each of the next four anniversaries of the grant dates. In certain instances, we may accelerate the vesting of an award, such as in connection with the award holder’s retirement as an officer of us or an officer or employee of RMR LLC. These awards to RMR LLC employees are in addition to the share awards to our Managing Trustees, as Trustee compensation, and the fees we paid to RMR LLC. See Note 9 for more information regarding our share awards and activity as well as certain share purchases we made in connection with share award recipients satisfying tax withholding obligations on vesting share awards. RMR Inc. On July 1, 2019, we sold all of the 2,801,060 shares of class A common stock of RMR Inc. that we owned in an underwritten public offering at a price to the public of $40.00 per share pursuant to an underwriting agreement among us, RMR Inc., certain other REITs managed by RMR LLC that also sold their class A common stock of RMR Inc. in the offering and the underwriters named therein. We received net proceeds of $104,674 from this sale, after deducting underwriting discounts and commissions and other offering expenses. SIR . As described further in Note 1, we completed the SIR Merger effective December 31, 2018. See Notes 3, 10 and 11 for more information regarding the SIR Merger and our former equity method investment in SIR. AIC . Until its dissolution on February 13, 2020, we, ABP Trust and five other companies to which RMR LLC provides management services owned AIC in equal amounts. We and the other AIC shareholders historically participated in a combined property insurance program arranged and insured or reinsured in part by AIC. The policies under that program expired on June 30, 2019, and we and the other AIC shareholders elected not to renew the AIC property insurance program; we have instead purchased standalone property insurance coverage with unrelated third party insurance providers. We paid aggregate annual premiums, including taxes and fees, of $1,211 , $757 and $1,032 in connection with this insurance program for the policy years ended June 30, 2019, 2018 and 2017, respectively. Properties we acquired as a result of the SIR Merger were already previously included in this insurance program because SIR was a participant in the program. SIR paid an annual premium, including taxes and fees, of $1,666 in connection with this insurance program for the policy year ended June 30, 2019. As of December 31, 2019, 2018 and 2017, our investment in AIC had a carrying value of $298 , $8,751 and $8,304 , respectively. These amounts are included in other assets in our consolidated balance sheets. We recognized income of $281 , $516 and $608 related to our investment in AIC for the years ended December 31, 2019, 2018 and 2017, respectively. These amounts are presented as equity in net earnings (losses) of investees in our consolidated statements of comprehensive income (loss). Our other comprehensive income (loss) includes our proportionate share of unrealized gains and (losses) on securities which are owned and held for sale by AIC of $90 , $(69) and $461 related to our investment in AIC for the years ended December 31, 2019, 2018 and 2017, respectively. On February 13, 2020, AIC was dissolved and in connection with its dissolution, we and each other AIC shareholder received an initial liquidating distribution of $9,000 from AIC in December 2019. RMR LLC historically provided management and administrative services to AIC for a fee equal to 3.0% of the total premiums paid for insurance arranged by AIC. As a result of the property insurance program having been discontinued as of June 30, 2019, AIC has not incurred fees payable to RMR LLC since that time. Directors’ and Officers’ Liability Insurance. We, RMR Inc., RMR LLC and certain other companies to which RMR LLC or its subsidiaries provide management services, including SIR (until it ceased to exist), participate in a combined directors’ and officers’ liability insurance policy. The current combined policy expires in September 2020. We paid aggregate premiums of $190 , $198 and $91

Concentration

Concentration	12 Months Ended
	Dec. 31, 2019
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, 2019 , the U.S. Government, 11 state governments, and two other government tenants combined were responsible for approximately 35.5% of our annualized rental income. As of December 31, 2018 and 2017 , the U.S. Government, 13 state governments and three other government tenants combined were responsible for 35.4% and 62.6% of our annualized rental income, respectively. The U.S. Government is our largest tenant by annualized rental income and represented approximately 25.0% , 25.6% and 43.5% of our annualized rental income as of December 31, 2019 , 2018 and 2017 , respectively. Geographic Concentration At December 31, 2019 , our 189 wholly owned properties were located in 35 states and the District of Columbia. Properties located in Virginia , California , the District of Columbia, Texas and Maryland were responsible for approximately 15.6% , 11.9% , 10.4% , 7.9% , and 6.6% of our annualized rental income as of December 31, 2019 , respectively. Properties located in the metropolitan Washington, D.C. market area were responsible for approximately 24.1% of our annualized rental income as of December 31, 2019 .

Indebtedness

Indebtedness	12 Months Ended
	Dec. 31, 2019
Debt Disclosure [Abstract]
Indebtedness	Indebtedness At December 31, 2019 and 2018 , our outstanding indebtedness consisted of the following: December 31, 2019 2018 Revolving credit facility, due in 2023 $ — $ 175,000 Unsecured term loan, due in 2020 — 300,000 Unsecured term loan, due in 2022 — 88,000 Senior unsecured notes, 3.750% interest rate, due in 2019 — 350,000 Senior unsecured notes, 3.600% interest rate, due in 2020 (1)(2) 400,000 400,000 Senior unsecured notes, 4.000% interest rate, due in 2022 300,000 300,000 Senior unsecured notes, 4.150% interest rate, due in 2022 (1) 300,000 300,000 Senior unsecured notes, 4.250% interest rate, due in 2024 (1) 350,000 350,000 Senior unsecured notes, 4.500% interest rate, due in 2025 (1) 400,000 400,000 Senior unsecured notes, 5.875% interest rate, due in 2046 310,000 310,000 Mortgage note payable, 7.000% interest rate, due in 2019 — 7,939 Mortgage note payable, 5.720% interest rate, due in 2020 32,888 33,703 Mortgage note payable, 4.160% interest rate, due in 2020 (1) 40,062 40,772 Mortgage note payable, 8.150% interest rate, due in 2021 1,683 2,912 Mortgage note payable, 5.877% interest rate, due in 2021 (3) 13,166 13,437 Mortgage note payable, 4.220% interest rate, due in 2022 26,522 27,210 Mortgage note payable, 3.550% interest rate, due in 2023 (1) 71,000 71,000 Mortgage note payable, 3.700% interest rate, due in 2023 (1) 50,000 50,000 Mortgage note payable, 4.800% interest rate, due in 2023 24,108 24,509 Mortgage note payable, 4.050% interest rate, due in 2030 66,780 66,780 2,386,209 3,311,262 Unamortized debt premiums, discounts and issuance costs (45,756 ) (56,372 ) $ 2,340,453 $ 3,254,890 (1) We assumed these senior unsecured notes and mortgage notes in connection with the SIR Merger. (2) In January 2020, we redeemed, at par plus accrued interest, all $400,000 of our 3.60% senior unsecured notes due 2020 using cash on hand, proceeds from property sales and borrowings under our revolving credit facility. (3) The carrying value of this mortgage note of $13,128 is net of unamortized issuance costs of $38 and is included in liabilities of properties held for sale in our consolidated balance sheet as of December 31, 2019. 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. The maturity date of our revolving credit facility is January 31, 2023 and, subject to our payment of an extension fee and meeting certain other conditions, we have the option to extend the stated maturity date of our revolving credit facility by two additional six month periods. 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, 2019 , 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, 2019 . Both the interest rate premium and facility fee are subject to adjustment based upon changes to our credit ratings. As of December 31, 2019 and 2018 , the annual interest rate payable on borrowings under our revolving credit facility was 2.7% and 3.6% , respectively. The weighted average annual interest rate for borrowings under our revolving credit facility was 3.3% , 3.0% and 2.4% , for the years ended December 31, 2019 , 2018 and 2017 , respectively. As of December 31, 2019 , we had no amounts outstanding under our revolving credit facility and $750,000 available for borrowing. As of February 19, 2020, we had $335,000 outstanding under our revolving credit facility and $415,000 available for borrowing under our revolving credit facility. During the year ended December 31, 2019, we repaid in full our $300,000 term loan, which was scheduled to mature on March 31, 2020, without penalty. The weighted average annual interest rate under this term loan was 3.9% for the period from January 1, 2019 to August 23, 2019, and 3.4% and 2.5% , for the years ended December 31, 2018 and 2017 , respectively. On February 11, 2019, we repaid the remaining $88,000 outstanding on our $250,000 term loan, which was scheduled to mature on March 31, 2022, without penalty. The weighted average annual interest rate under this term loan was 4.3% for the period from January 1, 2019 to February 11, 2019, and 3.8% and 2.9% for the years ended December 31, 2018 and 2017 , respectively. As a result of the principal payments of our term loans, we recognized a loss on early extinguishment of debt of $643 during the year ended December 31, 2019 , to write off unamortized debt issuance costs. In July 2019, we redeemed, at par plus accrued interest, all $350,000 of our 3.75% senior unsecured notes due 2019. As a result of the redemption of our 3.75% senior unsecured notes due 2019, we recognized a loss on early extinguishment of debt of $126 during the year ended December 31, 2019 to write off unamortized debt issuance costs and discounts. In January 2020, we redeemed, at par plus accrued interest, all $400,000 of our 3.60% senior unsecured notes due 2020. 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 LLC ceasing to act as our business and property manager. Our credit agreement and our 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 and other 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, 2019 . On March 1, 2019, we repaid at maturity, at par plus accrued interest, a mortgage note secured by one property with an outstanding principal balance of $7,890 using cash on hand. At December 31, 2019 , 11 of our consolidated properties with an aggregate net book value of $597,619 were encumbered by mortgage notes with an aggregate principal amount of $326,209 , including one mortgage note with an outstanding principal balance of $13,166 classified in liabilities of properties held for sale in our consolidated balance sheet. Our mortgage notes are non-recourse, subject to certain limited exceptions and do 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, 2019 are as follows: Year Principal Payment 2020 $ 475,707 2021 14,420 2022 625,518 2023 143,784 2024 350,000 Thereafter 776,780 $ 2,386,209 (1) (1) Total consolidated debt outstanding as of December 31, 2019 , net of unamortized premiums, discounts and issuance costs totaling $45,756 , was $2,340,453 .

Fair Value of Assets and Liabil

Fair Value of Assets and Liabilities	12 Months Ended
	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Fair Value of Assets and Liabilities	Fair Value of Assets and Liabilities The following table presents certain of our assets measured at fair value at December 31, 2019 , categorized by the level of inputs, as defined in the fair value hierarchy under GAAP, used in the valuation of each asset: Fair Value at Reporting Date Using Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Description Total (Level 1) (Level 2) (Level 3) Non-Recurring Fair Value Measurements Assets: Assets of properties held for sale (1) $ 30,100 $ — $ 30,100 $ — (1) We recorded impairment charges of $9,454 to reduce the carrying value of one property that is classified as held for sale in our consolidated balance sheet to its estimated fair value, less costs to sell of $682 , based upon a negotiated sale price with a third party buyer (a Level 2 input as defined in the fair value hierarchy under GAAP). See Note 3 for more information. In addition to the assets described in the table above, our financial instruments include our cash and cash equivalents, restricted cash, rents receivable, a mortgage note receivable, accounts payable, a revolving credit facility, senior unsecured notes, mortgage notes payable, amounts due to related persons, other accrued expenses and security deposits. At December 31, 2019 and 2018, 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, 2019 As of December 31, 2018 Financial Instrument Carrying Value (1) Fair Value Carrying Value (1) Fair Value Senior unsecured notes, 3.750% interest rate, due in 2019 $ — $ — $ 349,239 $ 348,903 Senior unsecured notes, 3.60% interest rate, due in 2020 (2) 399,934 400,048 399,146 399,146 Senior unsecured notes, 4.00% interest rate, due in 2022 297,657 306,096 296,735 295,047 Senior unsecured notes, 4.15% interest rate, due in 2022 297,795 307,221 296,736 296,736 Senior unsecured notes, 4.25% interest rate, due in 2024 340,018 364,602 337,736 337,736 Senior unsecured notes, 4.50% interest rate, due in 2025 381,055 419,578 377,329 377,329 Senior unsecured notes, 5.875% interest rate, due in 2046 300,920 322,028 300,576 274,288 Mortgage notes payable (3) 323,074 331,675 335,241 336,365 Total $ 2,340,453 $ 2,451,248 $ 2,692,738 $ 2,665,550 (1) Includes unamortized debt premiums, discounts and issuance costs totaling $45,756 and $55,524 as of December 31, 2019 and 2018 , respectively. (2) In January 2020, we redeemed, at par plus accrued interest, all $400,000 of our 3.60% senior unsecured notes due 2020 using cash on hand, proceeds from property sales and borrowings under our revolving credit facility. (3) Includes one mortgage note with a carrying value of $13,128 net of unamortized issuance costs totaling $38 which is classified in liabilities of properties held for sale in our consolidated balance sheet as of December 31, 2019 . We estimated the fair value of our senior unsecured notes (except for our senior unsecured notes due 2046) using an average of the bid and ask price of the notes as of the measurement date (Level 2 inputs as defined in the fair value hierarchy under GAAP). We estimated the fair value of our senior unsecured notes due 2046 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 as of the measurement date (Level 3 inputs as defined in the fair value hierarchy under GAAP). Because Level 3 inputs are unobservable, our estimated fair value may differ materially from the actual fair value.

Shareholders' Equity

Shareholders' Equity	12 Months Ended
	Dec. 31, 2019
Equity [Abstract]
Shareholders' Equity	Shareholders’ Equity Share Awards We have common shares available for issuance under the terms of the 2009 Incentive Share Award Plan, or the 2009 Plan. During the years ended December 31, 2019 , 2018 and 2017 , we granted to our officers and other employees of RMR LLC annual share awards of 103,100 , 14,675 and 14,337 of our common shares, respectively, valued at $3,080 , $995 and $1,067 , in aggregate, respectively. We also granted each of our eight Trustees 3,000 of our common shares in 2019 with an aggregate value of $575 ( $72 per Trustee), each of our then six Trustees 750 common shares in 2018 with an aggregate value of $254 ( $42 per Trustee) and each of our then six Trustees 750 common shares in 2017 with an aggregate value of $392 ( $65 per Trustee) as part of their annual compensation. In addition, we granted 3,000 of our common shares, with a value of $270 ( $90 per Trustee) in connection with the election of three of our Trustees in 2019 and 750 of our common shares, with a value of $41 in connection with the election of one of our Trustees in 2018. The values of the share grants were based upon the closing price of our common shares trading on Nasdaq on the date of grant. The common shares awarded to our Trustees vested immediately. The common shares granted to our officers and certain other employees of RMR LLC vest in five equal annual installments beginning on the date of grant. We include the value of granted shares in general and administrative expenses ratably over the vesting period. A summary of shares granted, forfeited, vested and unvested under the terms of the 2009 Plan for the years ended December 31, 2019 , 2018 and 2017 , is as follows: 2019 2018 2017 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 55,321 $ 73.25 26,062 $ 78.24 24,743 $ 82.36 Granted 136,100 $ 28.84 19,925 $ 64.73 18,837 $ 77.44 Forfeited (1,474 ) $ 49.10 (255 ) $ 52.96 — $ — Vested (83,267 ) $ 27.78 (18,634 ) $ 63.80 (17,518 ) $ 83.20 Unvested acquired in the SIR Merger (1) — $ — 28,223 $ 27.48 — $ — Unvested at end of year 106,680 $ 40.16 55,321 $ 73.25 26,062 $ 78.24 (1) Represents unvested shares granted under SIR’s equity compensation plan that were converted into shares under the 2009 Plan, and which will have similar vesting requirements as shares granted under the 2009 Plan. The 106,680 unvested shares as of December 31, 2019 are scheduled to vest as follows: 32,677 shares in 2020, 28,875 shares in 2021, 24,808 shares in 2022 and 20,320 shares in 2023. As of December 31, 2019 , the estimated future compensation expense for the unvested shares was $3,672 . The weighted average period over which the compensation expense will be recorded is approximately 25 months . During the years ended December 31, 2019 , 2018 and 2017 , we recorded $3,088 , $1,337 and $1,377 , respectively, of compensation expense related to the 2009 Plan. At December 31, 2019 , 211,334 of our common shares remained available for issuance under the 2009 Plan. Share Purchases During the years ended December 31, 2019 , 2018 and 2017 we purchased 15,588 , 4,984 and 3,590 of our common shares, respectively, at weighted average prices of $29.76 , $46.54 , $73.63 per common share, respectively, from our Trustees and current and former officers and employees of RMR LLC 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, 2019 , 2018 and 2017 , we paid distributions on our common shares as follows: Annual Per Share Distribution Total Distribution Characterization of Distribution Year Return of Capital Ordinary Income Qualified Dividend 2019 $ 2.20 $ 105,868 —% 100.00% —% 2018 $ 6.88 $ 170,566 68.60% 31.40% —% 2017 $ 6.88 $ 145,209 49.35% 50.65% —% On January 16, 2020, we declared a dividend payable to common shareholders of record on January 27, 2020 in the amount of $0.55 per share, or $26,511 . We expect to pay this distribution on or about February 20, 2020. 2017 Sale of Shares On July 5, 2017, we sold 6,250,000 of our common shares at a price of $74.00 per share in an underwritten public offering. On August 3, 2017, we sold 726,757 of our common shares at a price of $74.00 per share pursuant to an overallotment option granted to the underwriters for the July offering. The aggregate net proceeds from these sales of $493,866 , after payment of the underwriters’ discount and other offering expenses, were used to finance, in part, the FPO Transaction. Cumulative Other Comprehensive Income (Loss) Cumulative other comprehensive income (loss) represents our share of the comprehensive income (loss) of our equity method investees, and prior to December 31, 2017, the unrealized gain (loss) on our former investment in RMR Inc. The following table presents changes in the amounts we recognized in cumulative other comprehensive income (loss) by component for the years ended December 31, 2019 , 2018 and 2017 : Unrealized Gain on Investment in Equity Securities Equity in Unrealized Gains (Losses) of Investees (1) Unrealized Loss on Financial Instrument (2) Total Balance at December 31, 2016 $ 21,074 $ 5,883 $ — $ 26,957 Other comprehensive income before reclassifications 24,042 9,462 — 33,504 Amounts reclassified from cumulative other comprehensive income to net income — (34 ) — (34 ) Net current period other comprehensive income 24,042 9,428 — 33,470 Balance at December 31, 2017 45,116 15,311 — 60,427 Amounts reclassified from cumulative other comprehensive income to retained earnings (45,116 ) (15,165 ) — (60,281 ) Balance at January 1, 2018 — 146 — 146 Other comprehensive loss before reclassifications — (3 ) — (3 ) Amounts reclassified from cumulative other comprehensive income to net loss — (37 ) — (37 ) Net current period other comprehensive loss — (40 ) — (40 ) Balance at December 31, 2018 — 106 — 106 Other comprehensive loss before reclassifications — 90 (200 ) (110 ) Amounts reclassified from cumulative other comprehensive income to net income — (196 ) — (196 ) Net current period other comprehensive loss — (106 ) (200 ) (306 ) Balance at December 31, 2019 $ — $ — $ (200 ) $ (200 ) (1) Amounts reclassified from cumulative other comprehensive income (loss) to net income (loss) is included in equity in net losses of investees in our consolidated statements of comprehensive income (loss). (2) Amounts reclassified from cumulative other comprehensive income (loss) to net income (loss) is included in interest expense in our consolidated statements of comprehensive income (loss). Preferred Units of Limited Partnership On May 1, 2018, one of our subsidiaries redeemed all 1,813,504 of its outstanding 5.5% Series A Cumulative Preferred Units for $11.15 per unit plus accrued and unpaid distributions (an aggregate of $20,310 ).

Equity Investment in Select Inc

Equity Investment in Select Income REIT	12 Months Ended
	Dec. 31, 2019
Equity Method Investments and Joint Ventures [Abstract]
Equity Investment in Select Income REIT	Equity Investment in Select Income REIT Until October 9, 2018, we owned 24,918,421 , or approximately 27.8% , of the then outstanding SIR common shares. As described in Note 1, we completed the Secondary Sale on that date. As a result of the Secondary Sale, we recorded a loss of $18,665 during the year ended December 31, 2018. We accounted for our investment in SIR under the equity method and had previously reported our investment in SIR as a reportable segment. As a result of the Secondary Sale and the elimination of a reportable segment, our former equity method investment in SIR is classified as discontinued operations in our consolidated statements of comprehensive income (loss). See Note 11 for more information regarding discontinued operations. Under the equity method, we recorded our proportionate share of SIR’s net income as equity in earnings of SIR in our consolidated statements of comprehensive income (loss). During the period from January 1, 2018 to October 9, 2018 and the year ended December 31, 2017, we recorded $24,358 and $21,584 of equity in earnings of SIR, respectively. Our other comprehensive income (loss) includes our proportionate share of SIR’s unrealized gains of $28 and $8,967 for the period from January 1, 2018 to October 9, 2018 and the year ended December 31, 2017 , respectively. The adjusted GAAP cost basis of our investment in SIR was less than our proportionate share of SIR’s total shareholders’ equity book value on the dates we acquired the shares. Prior to the Secondary Sale, we were accreting a basis difference to earnings over the estimated remaining useful lives of certain real estate assets and intangible assets and liabilities owned by SIR. This accretion increased our equity in the earnings of SIR by $3,233 and $2,944 for the period from January 1, 2018 to October 9, 2018 and the year ended December 31, 2017 , respectively. During the period from January 1, 2018 to October 9, 2018 and the year ended December 31, 2017 , we received cash distributions from SIR totaling $38,124 and $50,832 , respectively. During the period from January 1, 2018 to October 9, 2018 and the year ended December 31, 2017 , SIR issued 63,157 and 59,502 common shares, respectively. We recognized a gain on issuance of shares by SIR of $29 and $72 during the period from January 1, 2018 to October 9, 2018, and the year ended December 31, 2017 , respectively, as a result of the per share issuance price of these SIR common shares being above the then average per share carrying value of our SIR common shares. The following table presents summarized income statement data of SIR: Nine Months Ended September 30, 2018 Year Ended December 31, 2017 Revenues: Rental income $ 298,003 $ 392,285 Tenant reimbursements and other income 60,514 75,818 Total revenues 358,517 468,103 Expenses: Real estate taxes 36,748 44,131 Other operating expenses 43,714 55,567 Depreciation and amortization 105,326 137,672 Acquisition and transaction related costs 3,796 1,075 General and administrative 47,353 54,909 Write-off of straight line rent receivable, net 10,626 12,517 Loss on asset impairment — 4,047 Loss on impairment of real estate assets 9,706 229 Total expenses 257,269 310,147 Gain on sale of real estate 4,075 — Dividend income 1,190 1,587 Unrealized gain on equity securities 53,159 — Interest income 753 91 Interest expense (69,446 ) (92,870 ) Loss on early extinguishment of debt (1,192 ) — Income before income tax expense and equity in earnings of an investee 89,787 66,764 Income tax expense (446 ) (466 ) Equity in earnings of an investee 882 608 Net income 90,223 66,906 Net income allocated to noncontrolling interest (15,841 ) — Net income attributed to SIR $ 74,382 $ 66,906 Weighted average common shares outstanding (basic) 89,395 89,351 Weighted average common shares outstanding (diluted) 89,411 89,370 Net income attributed to SIR per common share (basic and diluted) $ 0.83 $ 0.75

Discontinued Operations

Discontinued Operations	12 Months Ended
	Dec. 31, 2019
Discontinued Operations and Disposal Groups [Abstract]
Discontinued Operations	Discontinued Operations As described in Note 1, on October 9, 2018, we sold all 24,918,421 SIR common shares that we then owned in the Secondary Sale. We recorded a loss of $18,665 during the year ended December 31, 2018 related to this sale. The sale of our SIR common shares qualifies as discontinued operations; accordingly, our former equity method investment in SIR is classified as discontinued operations in our consolidated statements of comprehensive income (loss). As described in Note 3, in August 2017, we sold one vacant office property in Falls Church, VA with 164,746 rentable square feet and a net book value of $12,901 as of the date of sale for $13,523 , excluding closing costs. Results of operations for this property, which qualified as held for sale prior to our adoption in 2014 of ASU No. 2014-8, Reporting Discontinued Operations and Disclosures of Disposals of Components of an Entity , are classified as discontinued operations in our consolidated statements of comprehensive income (loss). The following table presents the components of income from discontinued operations for the years ended December 31, 2019, 2018 and 2017: Year Ended December 31, 2019 2018 2017 Equity in earnings of Select Income REIT $ — $ 24,358 $ 21,584 Net gain on issuance of shares by Select Income REIT — 29 72 Loss on sale of Select Income REIT shares — (18,665 ) — Income from property discontinued operations — — 173 Income from discontinued operations $ — $ 5,722 $ 21,829

Selected Quarterly Financial Da

Selected Quarterly Financial Data (Unaudited)	12 Months Ended
	Dec. 31, 2019
Quarterly Financial Information Disclosure [Abstract]
Selected Quarterly Financial Data (Unaudited)	Selected Quarterly Financial Data (Unaudited) The following is a summary of our unaudited quarterly results of operations for 2019 and 2018 . 2019 First Quarter Second Quarter Third Quarter Fourth Quarter Rental income $ 174,777 $ 176,032 $ 167,411 $ 160,184 Net income (loss) available for common shareholders $ 34,019 $ (64,774 ) $ (3,939 ) $ 65,029 Net income (loss) available for common shareholders per common share (basic and diluted) $ 0.71 $ (1.35 ) $ (0.08 ) $ 1.35 Common distributions declared $ 0.55 $ 0.55 $ 0.55 $ 0.55 2018 First Second Third Fourth Rental income $ 108,717 $ 108,085 $ 106,102 $ 103,656 Net income (loss) available for common shareholders $ 6,287 $ 29,602 $ (449 ) $ (57,695 ) Net income (loss) available for common shareholders per common share (basic and diluted) $ 0.25 $ 1.20 $ (0.02 ) $ (2.31 ) Common distributions declared $ 1.72 $ 1.72 $ 1.72 $ 1.72

SCHEDULE III REAL ESTATE AND AC

SCHEDULE III REAL ESTATE AND ACCUMULATED DEPRECIATION	12 Months Ended
	Dec. 31, 2019
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 Inverness Center Birmingham, AL 3 $ — $ 5,907 $ 12,098 $ 1,372 $ — $ 5,907 $ 13,470 $ 19,377 $ (425 ) 12/31/2018 1984 445 Jan Davis Drive Huntsville, AL 1 — 1,501 1,492 — — 1,501 1,492 2,993 (40 ) 12/31/2018 2007 4905 Moores Mill Road Huntsville, AL 1 — 4,592 36,324 1,627 — 4,592 37,951 42,543 (1,093 ) 12/31/2018 1979 131 Clayton Street Montgomery, AL 1 — 920 9,084 216 — 920 9,300 10,220 (1,942 ) 6/22/2011 2007 4344 Carmichael Road Montgomery, AL 1 — 1,374 11,658 233 — 1,374 11,891 13,265 (1,752 ) 12/17/2013 2009 15451 North 28th Avenue Phoenix, AZ 1 — 1,917 7,416 625 — 1,917 8,041 9,958 (1,054 ) 9/10/2014 1996 16001 North 28th Avenue Phoenix, AZ 1 — 3,355 412 44 — 3,355 456 3,811 (14 ) 12/31/2018 1998 711 S 14th Avenue Safford, AZ 1 — 460 11,708 790 (4,440 ) 364 8,154 8,518 (454 ) 6/16/2010 1992 Regents Center Tempe, AZ 2 — 4,121 3,042 — — 4,121 3,042 7,163 (149 ) 12/31/2018 1988 Campbell Place Carlsbad, CA 2 — 5,769 3,871 549 — 5,769 4,420 10,189 (115 ) 12/31/2018 2007 Folsom Corporate Center Folsom, CA 1 — 2,904 5,583 — — 2,904 5,583 8,487 (174 ) 12/31/2018 2008 Bayside Technology Park Fremont, CA 1 — 10,784 648 (1 ) — 10,784 647 11,431 (21 ) 12/31/2018 1990 5045 East Butler Street Fresno, CA 1 — 7,276 61,118 139 — 7,276 61,257 68,533 (26,566 ) 8/29/2002 1971 10949 N. Mather Boulevard Rancho Cordova, CA 1 — 562 16,923 916 — 562 17,839 18,401 (2,655 ) 10/30/2013 2012 11020 Sun Center Drive Rancho Cordova, CA 1 — 1,466 8,797 1,401 — 1,466 10,198 11,664 (808 ) 12/20/2016 1983 100 Redwood Shores Parkway Redwood City, CA 1 — 14,454 7,721 — — 14,454 7,721 22,175 (214 ) 12/31/2018 1993 3875 Atherton Road Rocklin, CA 1 — 177 853 — — 177 853 1,030 (23 ) 12/31/2018 1991 801 K Street Sacramento, CA 1 — 4,688 61,994 7,087 — 4,688 69,081 73,769 (8,306 ) 1/29/2016 1989 9815 Goethe Road Sacramento, CA 1 — 1,450 9,465 1,523 — 1,450 10,988 12,438 (2,307 ) 9/14/2011 1992 Capitol Place Sacramento, CA 1 — 2,290 35,891 9,822 — 2,290 45,713 48,003 (12,081 ) 12/17/2009 1988 4560 Viewridge Road San Diego, CA 1 — 4,269 18,316 4,319 — 4,347 22,557 26,904 (11,467 ) 3/31/1997 1996 2115 O’Nel Drive San Jose, CA 1 — 12,305 5,062 — — 12,305 5,062 17,367 (140 ) 12/31/2018 1984 North First Street San Jose, CA 1 — 8,311 4,003 188 — 8,311 4,191 12,502 (116 ) 12/31/2018 1984 Rio Robles Drive San Jose, CA 3 — 23,687 13,698 614 — 23,687 14,312 37,999 (403 ) 12/31/2018 1984 2450 and 2500 Walsh Avenue Santa Clara, CA 2 — 13,374 16,651 — — 13,374 16,651 30,025 (461 ) 12/31/2018 1982 3250 and 3260 Jay Street Santa Clara, CA 2 — 19,899 14,051 — — 19,899 14,051 33,950 (390 ) 12/31/2018 1982 603 San Juan Avenue Stockton, CA 1 — 563 5,470 — — 563 5,470 6,033 (1,015 ) 7/20/2012 2012 350 West Java Drive Sunnyvale, CA 1 — 24,609 462 21 — 24,609 483 25,092 (14 ) 12/31/2018 1984 7958 South Chester Street Centennial, CO 1 — 6,682 7,153 105 — 6,682 7,258 13,940 (200 ) 12/31/2018 2000 350 Spectrum Loop Colorado Springs, CO 1 — 3,650 7,732 86 — 3,650 7,818 11,468 (219 ) 12/31/2018 2000 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 333 Inverness Drive South Englewood, CO 1 — 5,711 4,543 — — 5,711 4,543 10,254 (136 ) 12/31/2018 1998 12795 West Alameda Parkway Lakewood, CO 1 1,687 2,640 23,777 1,339 — 2,640 25,116 27,756 (6,195 ) 1/15/2010 1988 Corporate Center Lakewood, CO 3 — 2,887 27,537 3,889 — 2,887 31,426 34,313 (13,409 ) 10/11/2002 1980 11 Dupont Circle, NW Washington, DC 1 64,686 28,255 44,743 5,095 — 28,255 49,838 78,093 (3,366 ) 10/2/2017 1974 1211 Connecticut Avenue, NW Washington, DC 1 26,542 30,388 24,667 2,168 — 30,388 26,835 57,223 (1,793 ) 10/2/2017 1967 1401 K Street, NW Washington, DC 1 24,502 29,215 34,656 4,461 — 29,215 39,117 68,332 (2,910 ) 10/2/2017 1929 20 Massachusetts Avenue Washington, DC 1 — 12,009 51,527 21,755 — 12,223 73,068 85,291 (37,223 ) 3/31/1997 1996 440 First Street, NW Washington, DC 1 — 27,903 38,624 1,332 — 27,903 39,956 67,859 (2,339 ) 10/2/2017 1982 625 Indiana Avenue Washington, DC 1 — 26,000 25,955 8,491 — 26,000 34,446 60,446 (8,694 ) 8/17/2010 1989 840 First Street, NE Washington, DC 1 33,219 42,727 73,278 2,222 — 42,727 75,500 118,227 (4,303 ) 10/2/2017 2003 10350 NW 112th Avenue Miami, FL 1 — 4,798 2,757 — — 4,798 2,757 7,555 (76 ) 12/31/2018 2002 7850 Southwest 6th Court Plantation, FL 1 — 4,800 30,592 383 — 4,800 30,975 35,775 (6,808 ) 5/12/2011 1999 8900 Grand Oak Circle Tampa, FL 1 — 1,100 11,773 427 — 1,100 12,200 13,300 (2,787 ) 10/15/2010 1994 180 Ted Turner Drive SW Atlanta, GA 1 — 5,717 20,017 295 — 5,717 20,312 26,029 (3,747 ) 7/25/2012 2007 Corporate Square Atlanta, GA 5 — 3,996 29,762 27,962 — 3,996 57,724 61,720 (15,442 ) 7/16/2004 1967 Executive Park Atlanta, GA 1 — 1,521 11,826 4,041 — 1,521 15,867 17,388 (6,437 ) 7/16/2004 1972 One Georgia Center Atlanta, GA 1 — 10,250 27,933 9,227 — 10,250 37,160 47,410 (6,646 ) 9/30/2011 1968 One Primerica Parkway Duluth, GA 1 — 6,927 22,951 — — 6,927 22,951 29,878 (636 ) 12/31/2018 2013 4712 Southpark Boulevard Ellenwood, GA 1 — 1,390 19,635 118 — 1,390 19,753 21,143 (3,653 ) 7/25/2012 2005 91-209 Kuhela Street Kapolei, HI 1 — 1,998 — 10 — 1,998 10 2,008 — 12/31/2018 Land 8305 NW 62nd Avenue Johnston, IA 1 — 2,649 7,997 — — 2,649 7,997 10,646 (221 ) 12/31/2018 2011 1185, 1249 & 1387 S. Vinnell Way Boise, ID 3 — 3,390 29,026 935 — 3,390 29,961 33,351 (5,684 ) 9/11/2012 1996; 1997; 2002 2020 S. Arlington Heights Arlington Heights, IL 1 — 1,450 13,588 444 — 1,450 14,032 15,482 (3,467 ) 12/29/2009 1988 400 South Jefferson Street Chicago, IL 1 49,299 19,379 20,115 — — 19,379 20,115 39,494 (558 ) 12/31/2018 1947 1415 West Diehl Road Naperville, IL 1 — 12,333 20,586 776 — 12,333 21,362 33,695 (636 ) 12/31/2018 2001 440 North Fairway Drive Vernon Hills, IL 1 — 4,465 441 — — 4,465 441 4,906 (13 ) 12/31/2018 1,992 7601 and 7635 Interactive Way Indianapolis, IN 2 — 3,337 14,522 26 — 3,337 14,548 17,885 (376 ) 12/31/2018 2003 Intech Park Indianapolis, IN 3 — 4,170 69,759 7,050 — 4,170 76,809 80,979 (15,777 ) 10/14/2011 2000; 2001; 2008 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 The Atrium at Circleport II Erlanger, KY 1 — 1,796 1,933 — — 1,796 1,933 3,729 (80 ) 12/31/2018 1999 7125 Industrial Road Florence, KY 1 — 1,698 11,722 293 — 1,698 12,015 13,713 (2,074 ) 12/31/2012 1980 251 Causeway Street Boston, MA 1 — 8,130 17,293 3,296 — 8,130 20,589 28,719 (4,708 ) 8/17/2010 1987 300 and 330 Billerica Road Chelmsford, MA 2 — 4,700 — 458 — 4,700 458 5,158 (3 ) 12/31/2018 1984 75 Pleasant Street Malden, MA 1 — 1,050 31,086 856 — 1,050 31,942 32,992 (7,500 ) 5/24/2010 2008 25 Newport Avenue Quincy, MA 1 — 2,700 9,199 1,879 — 2,700 11,078 13,778 (2,464 ) 2/16/2011 1985 One Montvale Avenue Stoneham, MA 1 — 1,670 11,035 2,693 — 1,670 13,728 15,398 (3,101 ) 6/16/2010 1945 314 Littleton Road Westford, MA 1 — 5,691 8,487 41 — 5,691 8,528 14,219 (238 ) 12/31/2018 2007 Annapolis Commerce Center Annapolis, MD 2 — 4,057 7,665 370 — 4,057 8,035 12,092 (523 ) 10/2/2017 1989 4201 Patterson Avenue Baltimore, MD 1 — 901 8,097 4,099 (85 ) 892 12,120 13,012 (5,401 ) 10/15/1998 1989 7001 Columbia Gateway Drive Columbia, MD 1 — 5,642 10,352 — — 5,642 10,352 15,994 (305 ) 12/31/2018 2008 Hillside Center Columbia, MD 2 — 3,437 4,228 576 — 3,437 4,804 8,241 (277 ) 10/2/2017 2001 TenThreeTwenty Columbia, MD 1 — 3,126 16,361 1,537 — 3,126 17,898 21,024 (1,177 ) 10/2/2017 1982 3300 75th Avenue Landover, MD 1 — 4,110 36,371 1,513 — 4,110 37,884 41,994 (9,310 ) 2/26/2010 1985 2115 East Jefferson Street Rockville, MD 1 — 3,349 11,152 436 — 3,349 11,588 14,937 (1,815 ) 8/27/2013 1981 Redland 520/530 Rockville, MD 3 — 12,714 61,377 1,744 — 12,714 63,121 75,835 (3,541 ) 10/2/2017 2008 Redland 540 Rockville, MD 1 — 10,740 17,714 6,001 — 10,740 23,715 34,455 (1,909 ) 10/2/2017 2003 Rutherford Business Park Windsor Mill, MD 1 — 1,598 10,219 472 — 1,598 10,691 12,289 (1,845 ) 11/16/2012 1972 3550 Green Court Ann Arbor, MI 1 — 3,630 4,857 — — 3,630 4,857 8,487 (142 ) 12/31/2018 1998 11411 E. Jefferson Avenue Detroit, MI 1 — 630 18,002 451 — 630 18,453 19,083 (4,402 ) 4/23/2010 2009 Rosedale Corporate Plaza Roseville, MN 1 — 672 6,045 1,526 — 672 7,571 8,243 (3,759 ) 12/1/1999 1987 1300 Summit Street Kansas City, MO 1 — 2,776 12,070 1,143 — 2,776 13,213 15,989 (2,399 ) 9/27/2012 1998 2555 Grand Boulevard Kansas City, MO 1 — 4,085 51,399 472 — 4,085 51,871 55,956 (1,408 ) 12/31/2018 2003 4241-4300 NE 34th Street Kansas City, MO 1 — 1,443 6,193 4,180 — 1,780 10,036 11,816 (4,523 ) 3/31/1997 1995 1220 Echelon Parkway Jackson, MS 1 — 440 25,458 258 — 440 25,716 26,156 (4,760 ) 7/25/2012 2009 2300 and 2400 Yorkmont Road Charlotte, NC 2 — 1,334 19,075 1,387 — 1,334 20,462 21,796 (587 ) 12/31/2018 1995 18010 and 18020 Burt Street Omaha, NE 2 — 6,977 12,500 — — 6,977 12,500 19,477 (346 ) 12/31/2018 2012 500 Charles Ewing Boulevard Ewing, NJ 1 — 4,808 26,002 — — 4,808 26,002 30,810 (721 ) 12/31/2018 2012 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 299 Jefferson Road Parsippany, NJ 1 — 4,543 2,914 493 — 4,543 3,407 7,950 (85 ) 12/31/2018 2011 One Jefferson Road Parsippany, NJ 1 — 4,415 5,249 10 — 4,415 5,259 9,674 (143 ) 12/31/2018 2009 Airline Corporate Center Colonie, NY 1 — 790 6,400 406 — 790 6,806 7,596 (1,253 ) 6/22/2012 2004 5000 Corporate Court Holtsville, NY 1 — 6,530 17,711 3,799 — 6,530 21,510 28,040 (4,492 ) 8/31/2011 2000 8687 Carling Road Liverpool, NY 1 — 566 — — — 566 — 566 — 12/31/2018 1997 1212 Pittsford - Victor Road Pittsford, NY 1 — 608 78 530 — 608 608 1,216 (5 ) 12/31/2018 1965 2231 Schrock Road Columbus, OH 1 — 716 217 101 — 716 318 1,034 (10 ) 12/31/2018 1999 4600 25th Avenue Salem, OR 1 — 6,510 17,973 6,658 — 6,510 24,631 31,141 (5,904 ) 12/20/2011 1957 8800 Tinicum Boulevard Philadelphia, PA 1 40,310 5,573 22,686 — — 5,573 22,686 28,259 (629 ) 12/31/2018 2000 9680 Old Bailes Road Fort Mill, SC 1 — 834 2,944 — — 834 2,944 3,778 (82 ) 12/31/2018 2007 One Memphis Place Memphis, TN 1 — 1,630 5,645 7,435 — 1,630 13,080 14,710 (2,996 ) 9/17/2010 1985 16001 North Dallas Parkway Addison, TX 2 — 10,158 63,036 331 — 10,158 63,367 73,525 (1,870 ) 12/31/2018 1987 Research Park Austin, TX 2 — 4,258 13,747 536 — 4,258 14,283 18,541 (835 ) 12/31/2018 1999 10451 Clay Road Houston, TX 1 — 5,495 10,253 — — 5,495 10,253 15,748 (284 ) 12/31/2018 2013 202 North Castlegory Road Houston, TX 1 — 863 5,024 — — 863 5,024 5,887 (131 ) 12/31/2018 2016 6380 Rogerdale Road Houston, TX 1 — 12,628 6,113 14 — 12,628 6,127 18,755 (170 ) 12/31/2018 2006 4221 W. John Carpenter Freeway Irving, TX 1 — 1,413 2,365 1,737 — 1,413 4,102 5,515 (123 ) 12/31/2018 1995 8675,8701-8711 Freeport Pkwy and 8901 Esters Boulevard Irving, TX 3 — 10,185 31,566 — — 10,185 31,566 41,751 (875 ) 12/31/2018 1990 1511 East Common Street New Braunfels, TX 1 — 4,965 1,266 67 — 4,965 1,333 6,298 (35 ) 12/31/2018 2005 2900 West Plano Parkway Plano, TX 1 — 6,819 8,831 — — 6,819 8,831 15,650 (244 ) 12/31/2018 1998 3400 West Plano Parkway Plano, TX 1 — 4,543 15,964 321 — 4,543 16,285 20,828 (451 ) 12/31/2018 1994 3600 Wiseman Boulevard San Antonio, TX 1 — 3,493 6,662 137 — 3,493 6,799 10,292 (194 ) 12/31/2018 2004 701 Clay Road Waco, TX 1 — 2,030 8,708 9,450 — 2,060 18,128 20,188 (5,351 ) 12/23/1997 1997 1800 Novell Place Provo, UT 1 — 7,487 43,487 — — 7,487 43,487 50,974 (1,301 ) 12/31/2018 2000 4885-4931 North 300 West Provo, UT 2 — 3,915 9,429 21 — 3,915 9,450 13,365 (276 ) 12/31/2018 2009 14660, 14672 & 14668 Lee Road Chantilly, VA 3 — 6,966 74,214 2,278 — 6,966 76,492 83,458 (5,879 ) 12/22/2016 1998; 2002; 2006 1434 Crossways Chesapeake, VA 2 — 3,617 19,527 2,010 — 3,617 21,537 25,154 (1,749 ) 10/2/2017 1998 Greenbrier Towers Chesapeake, VA 2 — 3,437 11,241 1,457 — 3,437 12,698 16,135 (1,080 ) 10/2/2017 1985 Enterchange at Meadowville Chester, VA 1 — 1,478 9,594 283 — 1,478 9,877 11,355 (1,558 ) 8/28/2013 1999 Pender Business Park Fairfax, VA 4 — 2,487 21,386 1,127 — 2,487 22,513 25,000 (3,530 ) 11/4/2013 2000 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 Three Flint Hill Fairfax, VA 1 — 5,991 25,536 2,897 — 5,991 28,433 34,424 (2,058 ) 10/2/2017 1984 7987 Ashton Avenue Manassas, VA 1 — 1,562 8,253 694 — 1,562 8,947 10,509 (717 ) 1/3/2017 1989 Two Commercial Place Norfolk, VA 1 — 4,494 21,508 389 — 4,494 21,897 26,391 (563 ) 12/31/2018 1974 1759 & 1760 Business Center Drive Reston, VA 2 — 9,066 78,658 4,093 — 9,066 82,751 91,817 (11,392 ) 5/28/2014 1987 1775 Wiehle Avenue Reston, VA 1 — 4,138 26,120 1,446 — 4,138 27,566 31,704 (1,583 ) 10/2/2017 2001 501 South 5th Street Richmond, VA 1 — 14,767 39,101 230 — 14,767 39,331 54,098 (1,134 ) 12/31/2018 2009 9201 Forest Hill Avenue Richmond, VA 1 — 1,344 375 150 — 1,344 525 1,869 (12 ) 12/31/2018 1985 9960 Mayland Drive Richmond, VA 1 — 2,614 15,930 2,440 — 2,614 18,370 20,984 (2,559 ) 5/20/2014 1994 Parham Place Richmond, VA 3 — 913 1,099 15 — 913 1,114 2,027 (31 ) 12/31/2018 1989; 2012 1751 Blue Hills Drive Roanoke, VA 1 — 2,689 7,761 — — 2,689 7,761 10,450 (215 ) 12/31/2018 2003 Atlantic Corporate Park Sterling, VA 2 — 5,752 29,316 2,055 — 5,752 31,371 37,123 (1,690 ) 10/2/2017 2008 Orbital Sciences Campus Sterling, VA 3 — 12,275 19,320 25 — 12,275 19,345 31,620 (570 ) 12/31/2018 2001 Sterling Business Park Lots 8 and 9 Sterling, VA 1 — 9,177 44,324 52 — 9,177 44,376 53,553 (2,493 ) 10/2/2017 2016 65 Bowdoin Street S. Burlington, VT 1 — 700 8,416 140 — 700 8,556 9,256 (2,090 ) 4/9/2010 2009 840 North Broadway Everett, WA 2 — 3,360 15,376 2,649 — 3,360 18,025 21,385 (3,716 ) 6/28/2012 1985 Stevens Center Richland, WA 2 — 3,970 17,035 4,456 — 4,042 21,419 25,461 (10,658 ) 3/31/1997 1995 351, 401, 501 Elliott Ave West Seattle, WA 3 69,701 26,640 52,740 654 — 26,640 53,394 80,034 (1,467 ) 12/31/2018 2000 11050 West Liberty Drive Milwaukee, WI 1 — 945 4,539 103 — 945 4,642 5,587 (998 ) 6/9/2011 2006 5353 Yellowstone Road Cheyenne, WY 1 — 1,915 8,217 1,346 — 1,950 9,528 11,478 (4,907 ) 3/31/1997 1995 183 $ 309,946 $ 839,889 $ 2,425,029 $ 232,838 $ (4,525 ) $ 840,550 $ 2,652,681 $ 3,493,231 $ (387,656 ) Properties Held for Sale — — — — 1 Targeting Center Windsor, CT 1 — 1,428 588 — — 1,428 588 2,016 (13 ) 12/31/2018 1980 475 Bond Street Lincolnshire, IL 1 — 4,764 552 — — 4,764 552 5,316 (11 ) 12/31/2018 2000 50 West State Street Trenton, NJ 1 — 5,000 38,203 3,337 (18,623 ) 3,866 24,051 27,917 — 12/30/2010 1989 3920 Pender Drive Fairfax, VA 1 13,128 2,934 12,840 538 — 2,934 13,378 16,312 (1,796 ) 3/21/2014 1981 Aquia Commerce Center Stafford, VA 2 — 2,090 7,465 784 — 2,090 8,249 10,339 (1,733 ) 6/22/2011 1988; 1999 6 13,128 16,216 59,648 4,659 (18,623 ) 15,082 46,818 61,900 (3,553 ) 189 $ 323,074 $ 856,105 $ 2,484,677 $ 237,497 $ (23,148 ) $ 855,632 $ 2,699,499 $ 3,555,131 $ (391,209 ) (1) Represents mortgage debt, net of the unamortized balance of the fair value adjustments and debt issuance costs totaling $ 3,135 . (2) Excludes the value of real estate intangibles. Aggregate cost for federal income tax purposes is approximately $6,971,434 . (3) Depreciation on building and improvements is provided for periods ranging up to 40 years and on equipment up to 12 years 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, 2016 $ 1,888,760 $ 296,804 Additions 1,100,138 45,315 Loss on asset impairment (9,490 ) — Disposals (3,687 ) (271 ) Balance at December 31, 2017 2,975,721 341,848 Additions 1,486,342 65,215 Loss on asset impairment (8,630 ) — Disposals (286,837 ) (18,740 ) Cost basis adjustment (1) (5,005 ) (5,005 ) Reclassification of assets of properties held for sale (216,955 ) (8,171 ) Balance at December 31, 2018 3,944,636 375,147 Additions 66,221 89,398 Loss on asset impairment (22,255 ) — Disposals (424,302 ) (64,167 ) Cost basis adjustment (1) (9,169 ) (9,169 ) Reclassification of assets of properties held for sale (61,900 ) (3,553 ) Balance at December 31, 2019 $ 3,493,231 $ 387,656 (1) Represents the reclassification between accumulated depreciation and building made to certain properties reclassified as assets of properties held for sale at fair value in accordance with GAAP.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2019
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	We regularly evaluate whether events or changes in circumstances have occurred that could indicate an impairment in the value of long lived assets. 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 lives of our long lived assets. If we change our estimate of the remaining lives, we allocate the carrying value of the affected assets over their revised remaining lives. 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, building 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 $2,710 , $2,903 and $2,764 during the years ended December 31, 2019 , 2018 and 2017 , 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 $195,268 , $91,472 and $53,410 during the years ended December 31, 2019 , 2018 and 2017 , 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, inducements and, until January 1, 2019, legal fees associated with our entering leases. We amortize those costs, which are included in depreciation and amortization expense, on a straight line basis over the terms of the respective leases. Effective January 1, 2019, in accordance with Financial Accounting Standards Board, or FASB, Accounting Standards Update, or ASU, No. 2016-02, Leases
Debt Issuance Costs	Debt Issuance Costs . Debt issuance costs include capitalized issuance or assumption costs related to borrowings, which are 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, 2019 and 2018 , debt issuance costs for our revolving credit facility were $4,125 and accumulated amortization of debt issuance costs for our revolving credit facility were $1,059 and $49
Equity Securities	Equity Securities. We previously owned 2,801,060 common shares of class A common stock of The RMR Group Inc., or RMR Inc., including 1,586,836 common shares acquired from SIR on December 31, 2018 in connection with the SIR Merger, that we sold on July 1, 2019 for net proceeds of $104,674 , after deducting underwriting discounts and commissions and other offering expenses. Prior to the sale of our shares of RMR Inc. class A common stock on July 1, 2019, our equity securities were recorded at fair value based on their quoted market price at the end of each reporting period. Effective January 1, 2018, changes in the fair value of our equity securities were recorded through earnings in accordance with ASU No. 2016-01, Recognition and Measurement of Financial Assets and Financial Liabilities . Prior to January 1, 2018, unrealized gains and losses on equity
Equity Method Investments	Equity Method Investments. We account for our investments in Affiliates Insurance Company, or AIC, until AIC was dissolved as described in Note 5, and SIR, until we sold the SIR common shares we owned as described in Note 1, using the equity method of accounting. Significant influence was present through common representation on the boards of trustees or directors of us, AIC, until February 13, 2020, and, SIR, until December 31, 2018. See Notes 5, 10 and 11 for more information of our investments in AIC and SIR. We also own 51% and 50% interests in two unconsolidated joint ventures which own three properties. The properties owned by these joint ventures are encumbered by an aggregate $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 investment in these joint ventures under the equity method of accounting. See Note 3 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.
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. In February 2016, FASB issued ASU No. 2016-02, Leases . In July 2018, the FASB issued ASU No. 2018-10, Codification Improvements to Topic 842, Leases and ASU No. 2018-11, Leases (Topic 842): Targeted Improvements . In December 2018, the FASB issued ASU No. 2018-20 Leases (Topic 842), Narrow-Scope Improvements for Lessors . Collectively, these standards set out the principles for the recognition, measurement, presentation and disclosure of leases for both parties to a contract (i.e., lessees and lessors). ASU No. 2016-02 requires lessees to apply a dual approach, classifying leases as either finance or operating leases based on the principle of whether or not the lease is effectively a financed purchase of the leased asset by the lessee. This classification will determine whether the lease expense is recognized based on an effective interest method or on a straight line basis over the term of the lease. ASU No. 2016-02 requires lessors to account for leases using an approach that is substantially equivalent to existing guidance for sales type leases, direct financing leases and operating leases. These standards were effective as of January 1, 2019. Upon adoption, we applied the package of practical expedients that has allowed us to not reassess (i) whether any expired or existing contracts are or contain leases, (ii) lease classification for any expired or existing leases and (iii) initial direct costs for any expired or existing leases. Furthermore, we applied the optional transition method in ASU No. 2018-11, which has allowed us to initially apply the new leases standard at the adoption date and recognize a cumulative effect adjustment to the opening balance of retained earnings in the adoption period, although we did not have an adjustment. Additionally, our leases met the criteria in ASU No. 2018-11 to not separate non-lease components from the related lease component; therefore, the accounting for these leases remained largely unchanged from the previous standard. The adoption of ASU No. 2016-02 and the related improvements did not have a material impact in our consolidated financial statements. Upon adoption, (i) allowances for bad debts are now recognized as a direct reduction of rental income, and (ii) legal costs associated with the execution of our leases, which were previously capitalized and amortized over the life of their respective leases, are expensed as incurred. Subsequent to January 1, 2019, provisions for credit losses are now included in rental income in our consolidated statements of comprehensive income (loss). Provisions for credit losses prior to January 1, 2019 were previously included in other operating expenses in our consolidated financial statements and prior periods are not reclassified to conform to the current presentation. 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. We increased rental income by $27,507 , $10,164 and $5,582 to record revenue on a straight line basis during the years ended December 31, 2019 , 2018 and 2017 , respectively. Rents receivable, excluding properties classified as held for sale, include $54,837 and $34,006 of straight line rent receivables at December 31, 2019 and 2018 , 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 $91,076 , $45,261 and $30,998 for the years ended December 31, 2019 , 2018 and 2017, respectively, of which tenant reimbursements totaled $86,353 , $40,764 and $27,146 , respectively. 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 determined that all of our leases qualify for the practical expedient 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. The following operating lease maturity analysis presents the future contractual lease payments to be received by us through 2039 as of December 31, 2019 : Year Amount 2020 $ 489,420 2021 466,210 2022 428,149 2023 381,164 2024 313,456 Thereafter 1,052,669 Total $ 3,131,068 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, 2019 , tenants who currently represent approximately 6.7% of our total operating lease maturities have currently exercisable rights to terminate their leases before the stated terms of their leases expire. In 2020 , 2021 , 2022 , 2023 , 2024 , 2025 , 2026 , 2027 , 2028 , 2030 and 2034 , early termination rights become exercisable by other tenants who currently represent an additional approximately 4.8% , 1.6% , 2.7% , 1.1% , 2.0% , 5.2% , 2.6% , 1.1% , 2.6% , 0.8% and 0.2% of our total operating lease maturities, respectively. In addition, as of December 31, 2019 , 13 of our tenants have the right to terminate their leases if the respective legislature or other funding authority does not appropriate the funding necessary for the
Income Taxes	Income Taxes.
Cumulative Other Comprehensive Income	Cumulative Other Comprehensive Income (Loss). Cumulative other comprehensive income (loss) represents our share of the cumulative comprehensive income and losses of our equity method investees and, prior to the adoption of ASU No. 2016-01 on January 1, 2018, unrealized gains and losses related to our former investment in RMR Inc. See Notes 3 and 5 for more information regarding these investments.
Per Common Share Amounts	Per Common Share Amounts. We calculate basic earnings per common share by dividing net income (loss) available for common shareholders by the weighted average number of our common shares of beneficial ownership, $.01
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.
Reclassifications	Reclassifications. Reclassifications have been made to the prior years’ consolidated financial statements to conform to the current year’s presentation.
Segment Reporting	Segment Reporting. We operate in one business segment: direct ownership of real estate properties.
New Accounting Pronouncements	New Accounting Pronouncements. In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments , which requires that entities use a new forward looking “expected loss” model that generally will result in the earlier recognition of allowance for credit losses. The measurement of expected credit losses is based upon historical experience, current conditions, and reasonable and supportable forecasts that affect the collectability of the reported amount. ASU No. 2016-13 is effective as of January 1, 2020. We adopted this standard using the modified retrospective approach. The implementation of this standard did not have a material impact in our consolidated financial statements.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Schedule of Real Estate Properties	As of December 31, 2019 and 2018 , our acquired real estate leases and assumed real estate obligations, excluding properties classified as held for sale, were as follows: December 31, 2019 2018 Acquired real estate leases: Capitalized above market lease values $ 61,971 $ 62,260 Less: accumulated amortization (29,927 ) (20,956 ) Capitalized above market lease values, net 32,044 41,304 Lease origination value 1,032,769 1,168,979 Less: accumulated amortization (332,431 ) (153,725 ) Lease origination value, net 700,338 1,015,254 Acquired real estate leases, net $ 732,382 $ 1,056,558 Assumed real estate lease obligations: Capitalized below market lease values $ 28,118 $ 31,091 Less: accumulated amortization (14,943 ) (11,060 ) Assumed real estate lease obligations, net $ 13,175 $ 20,031

Real Estate Properties (Tables)

Real Estate Properties (Tables)	12 Months Ended
	Dec. 31, 2019
Real Estate [Abstract]
Schedule of Allocation of Purchase Price	The following table summarizes the total consideration paid and the estimated fair values of the assets acquired and liabilities assumed in the FPO Transaction: Total Purchase Price: Cash consideration $ 1,175,140 Acquisition related costs 9,575 Total cash consideration 1,184,715 Preferred units of limited partnership issued (1) 20,221 Acquired net working capital (1,596 ) Assumed mortgage notes 167,548 Non-cash portion of purchase price 186,173 Gross purchase price $ 1,370,888 Purchase Price Allocation: Land $ 360,909 Buildings and improvements 681,340 Acquired real estate leases (2) 283,498 Investment in unconsolidated joint ventures 51,305 Cash 11,191 Restricted cash 1,018 Rents receivable 2,672 Other assets 3,640 Total assets 1,395,573 Mortgage notes payable (3) (167,936 ) Assumed real estate lease obligations (2) (5,776 ) Accounts payable and accrued expenses (10,640 ) Rents collected in advance (1,436 ) Security deposits (4,849 ) Net assets acquired 1,204,936 Assumed working capital (1,596 ) Assumed principal balance of debt 167,548 Gross purchase price $ 1,370,888 (1) Pursuant to the terms of the FPO Transaction, each unit of limited partnership interest in FPO’s operating partnership that was not liquidated on the closing date was exchanged on a one-for-one basis for 5.5% Series A Cumulative Preferred Units of the surviving subsidiary. As of December 31, 2017, the carrying value of these Series A Cumulative Preferred Units was $20,496 and was recorded as temporary equity on our consolidated balance sheet. On May 1, 2018, we redeemed all 1,813,504 of the outstanding 5.5% Series A Cumulative Preferred Units for $11.15 per unit (plus accrued and unpaid distributions) for an aggregate of $20,310 . (2) As of the date acquired, the weighted average amortization periods for capitalized above market lease values, lease origination value and capitalized below market lease values were 3.2 years , 3.1 years and 3.8 years , respectively. (3) Includes fair value adjustments totaling $388 on $167,936 principal amount of mortgage notes we assumed in connection with the FPO Transaction. Acquisition Date Location Number of Properties Square Feet Purchase Price Land Building and Improvements Other Assumed Assets Jan 2017 Manassas, VA 1 69,374 $ 12,657 $ 1,562 $ 8,253 $ 2,842 Purchase Price Allocation: Land $ 477,977 Buildings and improvements 956,801 Assets of properties held for sale 6,846 Acquired real estate leases 854,431 Cash 24,744 Restricted cash 476 Rents receivable 11,370 Other assets (1) 88,658 Total assets 2,421,303 Unsecured revolving credit facility (2) (108,000 ) Senior unsecured notes (3) (1,410,947 ) Mortgage notes payable (4) (159,490 ) Accounts payable and other liabilities (61,289 ) Assumed real estate lease obligations (11,879 ) Due to related persons (30,120 ) Net assets acquired 639,578 Assumed working capital 50,390 Select Income REIT unsecured revolving credit facility repaid at closing (2) 108,000 Assumed senior unsecured notes, principal balance 1,450,000 Assumed mortgage notes payable, principal balance 161,772 Consideration transferred and liabilities assumed (5) $ 2,409,740 (1) Other assets include $84,229 for SIR’s investment in shares of class A common stock of RMR Inc. which was recorded at fair value as of December 31, 2018. (2) We repaid the outstanding balance under SIR’s revolving credit facility at the closing of the SIR Merger with borrowings under our revolving credit facility. (3) The aggregate principal balance of the senior unsecured notes was $1,450,000 as of December 31, 2018. (4) The aggregate principal balance of the mortgage notes payable was $161,772 as of December 31, 2018. (5) Purchase price excludes acquisition related costs. The following table summarizes the consideration transferred and liabilities assumed: Total Purchase Price (excluding acquisition costs): OPI common shares issued 23,282,704 Closing price of OPI common shares on December 31, 2018 $ 27.48 Value of consideration transferred $ 639,809 Cash consideration for fractional shares 8 Equity issuance costs (239 ) Value of consideration transferred 639,578 Assumed working capital 50,390 Assumed senior unsecured notes, principal balance 1,450,000 Assumed mortgage notes payable, principal balance 161,772 Select Income REIT unsecured revolving credit facility repaid at closing 108,000 Non-cash portion of purchase price 1,770,162 Total consideration transferred and liabilities assumed $ 2,409,740
Schedule of Pro Forma Information	The following table presents our pro forma results of operations for the year ended December 31, 2018 as if the SIR Transactions and related financing activities, had occurred on January 1, 2018. The SIR results of operations included in this pro forma financial information have been adjusted to remove ILPT’s results of operations for the year ended December 31, 2018. The effect of these adjustments was to decrease pro forma rental income and pro forma net income by $152,735 and $46,237 , respectively, for the year ended December 31, 2018. This pro forma financial information is not necessarily indicative of what our actual financial position or results of operations would have been for the period presented or for any future period. Differences could result from numerous factors, including future changes in our portfolio of investments, capital structure, property level operating expenses and revenues, including rents expected to be received on our existing leases, leases we entered since December 31, 2018, or leases we may enter in the future, changes in interest rates and other reasons. Actual future results are likely to be different from amounts presented in this pro forma financial information and such differences could be significant. Year Ended December 31, 2018 Rental income $ 758,596 Net loss $ (87,240 ) Net loss per common share $ (1.82 )
Schedule of Joint Ventures	As of December 31, 2019 and 2018 , our investment in unconsolidated joint ventures consisted of the following: OPI Ownership OPI Carrying Value of Investment at December 31, Number of Properties Location Square Feet Joint Venture 2019 2018 Prosperity Metro Plaza 51% $ 22,483 $ 23,969 2 Fairfax, VA 328,456 1750 H Street, NW 50% 17,273 19,696 1 Washington, D.C. 115,411 Total $ 39,756 $ 43,665 3 443,867 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, 2019 and 2018 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
Schedule of Disposal Groups	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). Date of Sale Number of Properties Location Square Feet Gross Sale Price (1) Gain (Loss) on Sale of Real Estate Loss on Impairment of Real Estate February 2019 34 Northern Virginia and Maryland 1,635,868 $ 198,500 $ — $ 732 March 2019 1 Washington, D.C. 129,035 70,000 22,075 — May 2019 1 Buffalo, NY 121,711 16,900 — 5,137 May 2019 1 Maynard, MA 287,037 5,000 (227 ) — June 2019 1 Kapolei, HI 416,956 7,100 — — July 2019 1 San Jose, CA 71,750 14,000 (270 ) — July 2019 1 Nashua, NH 321,800 25,000 8,401 — August 2019 1 Arlington, TX 182,630 14,900 187 — August 2019 1 Rochester, NY 94,800 4,765 (104 ) — August 2019 1 Hanover, PA 502,300 5,500 (417 ) — August 2019 1 San Antonio, TX 618,017 198,000 3,869 — September 2019 1 Topeka, KS 143,934 15,600 36 — September 2019 1 Falling Waters, WV 40,348 650 — 2,179 September 2019 1 San Diego, CA 43,918 8,950 3,062 — October 2019 3 Columbia, SC 180,703 10,750 — 3,581 November 2019 3 Metro DC - MD 372,605 61,938 1,177 — December 2019 1 San Diego, CA 148,488 23,750 6,823 — December 2019 1 Phoenix, AZ 122,646 12,850 860 — December 2019 1 Houston, TX 497,477 130,000 59,992 — December 2019 1 Kansas City, KS 170,817 11,700 — 1,172 December 2019 1 San Jose, CA 75,621 13,000 (333 ) — 58 6,178,461 $ 848,853 $ 105,131 $ 12,801 (1) Gross sale price is the gross contract price, includes purchase price adjustments, if any, and excludes closing costs. As of December 31, 2019, we had six properties with an aggregate undepreciated carrying value of $61,900 under agreements to sell, as presented in the following table. We have classified these properties as held for sale in our consolidated balance sheet at December 31, 2019. Date of Sale Agreement Number of Properties Location Square Feet Gross Sale Price (1) October 2019 (2) 2 Stafford, VA 64,656 $ 14,063 October 2019 1 Fairfax, VA 83,130 22,200 October 2019 (2) 1 Windsor, CT 97,256 7,000 November 2019 (3) 1 Trenton, NJ 267,025 30,100 November 2019 1 Lincolnshire, IL 222,717 12,000 6 734,784 $ 85,363 (1) Gross sale price is the gross contract price, includes purchase price adjustments, if any, and excludes closing costs. (2) The sale of these properties was completed in January 2020. (3) We recorded a $9,454 loss on impairment of real estate during the year ended December 31, 2019 to adjust the carrying value of this property to its estimated fair value less costs to sell. Date of Sale Number of Properties Location Square Feet Gross Sale Price (1) Gain on Sale of Real Estate Loss on Impairment of Real Estate March 2018 1 Minneapolis, MN 193,594 $ 20,000 $ — $ 640 May 2018 1 New York, NY 187,060 118,500 17,249 — May 2018 1 Sacramento, CA 110,500 10,755 — 3,029 November 2018 1 Golden, CO 43,231 4,000 54 — December 2018 15 Southern Virginia 1,640,252 167,000 3,358 — 19 2,174,637 $ 320,255 $ 20,661 $ 3,669 (1) Gross sale price is the gross contract price, includes purchase price adjustments, if any, and excludes closing costs. Summarized income statement information for this property is as follows: Statements of Income (Loss) Year Ended December 31, 2017 Rental income $ 17 Real estate taxes (88 ) Utility expenses (97 ) Other operating expenses (202 ) General and administrative (76 ) Increase in carrying value of property included in discontinued operations 619 Income from discontinued operations $ 173 The following table presents the components of income from discontinued operations for the years ended December 31, 2019, 2018 and 2017: Year Ended December 31, 2019 2018 2017 Equity in earnings of Select Income REIT $ — $ 24,358 $ 21,584 Net gain on issuance of shares by Select Income REIT — 29 72 Loss on sale of Select Income REIT shares — (18,665 ) — Income from property discontinued operations — — 173 Income from discontinued operations $ — $ 5,722 $ 21,829

Indebtedness (Tables)

Indebtedness (Tables)	12 Months Ended
	Dec. 31, 2019
Debt Disclosure [Abstract]
Schedule of Long-Term Debt Instruments	At December 31, 2019 and 2018 , our outstanding indebtedness consisted of the following: December 31, 2019 2018 Revolving credit facility, due in 2023 $ — $ 175,000 Unsecured term loan, due in 2020 — 300,000 Unsecured term loan, due in 2022 — 88,000 Senior unsecured notes, 3.750% interest rate, due in 2019 — 350,000 Senior unsecured notes, 3.600% interest rate, due in 2020 (1)(2) 400,000 400,000 Senior unsecured notes, 4.000% interest rate, due in 2022 300,000 300,000 Senior unsecured notes, 4.150% interest rate, due in 2022 (1) 300,000 300,000 Senior unsecured notes, 4.250% interest rate, due in 2024 (1) 350,000 350,000 Senior unsecured notes, 4.500% interest rate, due in 2025 (1) 400,000 400,000 Senior unsecured notes, 5.875% interest rate, due in 2046 310,000 310,000 Mortgage note payable, 7.000% interest rate, due in 2019 — 7,939 Mortgage note payable, 5.720% interest rate, due in 2020 32,888 33,703 Mortgage note payable, 4.160% interest rate, due in 2020 (1) 40,062 40,772 Mortgage note payable, 8.150% interest rate, due in 2021 1,683 2,912 Mortgage note payable, 5.877% interest rate, due in 2021 (3) 13,166 13,437 Mortgage note payable, 4.220% interest rate, due in 2022 26,522 27,210 Mortgage note payable, 3.550% interest rate, due in 2023 (1) 71,000 71,000 Mortgage note payable, 3.700% interest rate, due in 2023 (1) 50,000 50,000 Mortgage note payable, 4.800% interest rate, due in 2023 24,108 24,509 Mortgage note payable, 4.050% interest rate, due in 2030 66,780 66,780 2,386,209 3,311,262 Unamortized debt premiums, discounts and issuance costs (45,756 ) (56,372 ) $ 2,340,453 $ 3,254,890 (1) We assumed these senior unsecured notes and mortgage notes in connection with the SIR Merger. (2) In January 2020, we redeemed, at par plus accrued interest, all $400,000 of our 3.60% senior unsecured notes due 2020 using cash on hand, proceeds from property sales and borrowings under our revolving credit facility. (3) The carrying value of this mortgage note of $13,128 is net of unamortized issuance costs of $38 and is included in liabilities of properties held for sale in our consolidated balance sheet as of December 31, 2019.
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, 2019 are as follows: Year Principal Payment 2020 $ 475,707 2021 14,420 2022 625,518 2023 143,784 2024 350,000 Thereafter 776,780 $ 2,386,209 (1) (1) Total consolidated debt outstanding as of December 31, 2019 , net of unamortized premiums, discounts and issuance costs totaling $45,756 , was $2,340,453 .

Fair Value of Assets and Liab_2

Fair Value of Assets and Liabilities (Tables)	12 Months Ended
	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Schedule of Assets Measured on a Non-Recurring Basis at Fair Value, Categorized by the Level of Inputs Used in the Valuation Assets	The following table presents certain of our assets measured at fair value at December 31, 2019 , categorized by the level of inputs, as defined in the fair value hierarchy under GAAP, used in the valuation of each asset: Fair Value at Reporting Date Using Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Description Total (Level 1) (Level 2) (Level 3) Non-Recurring Fair Value Measurements Assets: Assets of properties held for sale (1) $ 30,100 $ — $ 30,100 $ — (1) We recorded impairment charges of $9,454 to reduce the carrying value of one property that is classified as held for sale in our consolidated balance sheet to its estimated fair value, less costs to sell of $682 , based upon a negotiated sale price with a third party buyer (a Level 2 input as defined in the fair value hierarchy under GAAP). See Note 3 for more information.
Schedule of Fair Value and Carrying Value of Financial Instruments	At December 31, 2019 and 2018, 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, 2019 As of December 31, 2018 Financial Instrument Carrying Value (1) Fair Value Carrying Value (1) Fair Value Senior unsecured notes, 3.750% interest rate, due in 2019 $ — $ — $ 349,239 $ 348,903 Senior unsecured notes, 3.60% interest rate, due in 2020 (2) 399,934 400,048 399,146 399,146 Senior unsecured notes, 4.00% interest rate, due in 2022 297,657 306,096 296,735 295,047 Senior unsecured notes, 4.15% interest rate, due in 2022 297,795 307,221 296,736 296,736 Senior unsecured notes, 4.25% interest rate, due in 2024 340,018 364,602 337,736 337,736 Senior unsecured notes, 4.50% interest rate, due in 2025 381,055 419,578 377,329 377,329 Senior unsecured notes, 5.875% interest rate, due in 2046 300,920 322,028 300,576 274,288 Mortgage notes payable (3) 323,074 331,675 335,241 336,365 Total $ 2,340,453 $ 2,451,248 $ 2,692,738 $ 2,665,550 (1) Includes unamortized debt premiums, discounts and issuance costs totaling $45,756 and $55,524 as of December 31, 2019 and 2018 , respectively. (2) In January 2020, we redeemed, at par plus accrued interest, all $400,000 of our 3.60% senior unsecured notes due 2020 using cash on hand, proceeds from property sales and borrowings under our revolving credit facility. (3) Includes one mortgage note with a carrying value of $13,128 net of unamortized issuance costs totaling $38 which is classified in liabilities of properties held for sale in our consolidated balance sheet as of December 31, 2019 .

Shareholders' Equity (Tables)

Shareholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2019
Equity [Abstract]
Summary of Shares Granted And Vested Under The Terms of The Entity's 2009 Plan	A summary of shares granted, forfeited, vested and unvested under the terms of the 2009 Plan for the years ended December 31, 2019 , 2018 and 2017 , is as follows: 2019 2018 2017 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 55,321 $ 73.25 26,062 $ 78.24 24,743 $ 82.36 Granted 136,100 $ 28.84 19,925 $ 64.73 18,837 $ 77.44 Forfeited (1,474 ) $ 49.10 (255 ) $ 52.96 — $ — Vested (83,267 ) $ 27.78 (18,634 ) $ 63.80 (17,518 ) $ 83.20 Unvested acquired in the SIR Merger (1) — $ — 28,223 $ 27.48 — $ — Unvested at end of year 106,680 $ 40.16 55,321 $ 73.25 26,062 $ 78.24 (1) Represents unvested shares granted under SIR’s equity compensation plan that were converted into shares under the 2009 Plan, and which will have similar vesting requirements as shares granted under the 2009 Plan.
Schedule of Dividends	During the years ended December 31, 2019 , 2018 and 2017 , we paid distributions on our common shares as follows: Annual Per Share Distribution Total Distribution Characterization of Distribution Year Return of Capital Ordinary Income Qualified Dividend 2019 $ 2.20 $ 105,868 —% 100.00% —% 2018 $ 6.88 $ 170,566 68.60% 31.40% —% 2017 $ 6.88 $ 145,209 49.35% 50.65% —%
Schedule of Changes In Each Component of Cumulative Other Comprehensive Income (Loss)	The following table presents changes in the amounts we recognized in cumulative other comprehensive income (loss) by component for the years ended December 31, 2019 , 2018 and 2017 : Unrealized Gain on Investment in Equity Securities Equity in Unrealized Gains (Losses) of Investees (1) Unrealized Loss on Financial Instrument (2) Total Balance at December 31, 2016 $ 21,074 $ 5,883 $ — $ 26,957 Other comprehensive income before reclassifications 24,042 9,462 — 33,504 Amounts reclassified from cumulative other comprehensive income to net income — (34 ) — (34 ) Net current period other comprehensive income 24,042 9,428 — 33,470 Balance at December 31, 2017 45,116 15,311 — 60,427 Amounts reclassified from cumulative other comprehensive income to retained earnings (45,116 ) (15,165 ) — (60,281 ) Balance at January 1, 2018 — 146 — 146 Other comprehensive loss before reclassifications — (3 ) — (3 ) Amounts reclassified from cumulative other comprehensive income to net loss — (37 ) — (37 ) Net current period other comprehensive loss — (40 ) — (40 ) Balance at December 31, 2018 — 106 — 106 Other comprehensive loss before reclassifications — 90 (200 ) (110 ) Amounts reclassified from cumulative other comprehensive income to net income — (196 ) — (196 ) Net current period other comprehensive loss — (106 ) (200 ) (306 ) Balance at December 31, 2019 $ — $ — $ (200 ) $ (200 ) (1) Amounts reclassified from cumulative other comprehensive income (loss) to net income (loss) is included in equity in net losses of investees in our consolidated statements of comprehensive income (loss). (2) Amounts reclassified from cumulative other comprehensive income (loss) to net income (loss) is included in interest expense in our consolidated statements of comprehensive income (loss).

Equity Investment in Select I_2

Equity Investment in Select Income REIT (Tables)	12 Months Ended
	Dec. 31, 2019
Equity Method Investments and Joint Ventures [Abstract]
Summarized Financial Data of Select Income Realty (SIR)	The following table presents summarized income statement data of SIR: Nine Months Ended September 30, 2018 Year Ended December 31, 2017 Revenues: Rental income $ 298,003 $ 392,285 Tenant reimbursements and other income 60,514 75,818 Total revenues 358,517 468,103 Expenses: Real estate taxes 36,748 44,131 Other operating expenses 43,714 55,567 Depreciation and amortization 105,326 137,672 Acquisition and transaction related costs 3,796 1,075 General and administrative 47,353 54,909 Write-off of straight line rent receivable, net 10,626 12,517 Loss on asset impairment — 4,047 Loss on impairment of real estate assets 9,706 229 Total expenses 257,269 310,147 Gain on sale of real estate 4,075 — Dividend income 1,190 1,587 Unrealized gain on equity securities 53,159 — Interest income 753 91 Interest expense (69,446 ) (92,870 ) Loss on early extinguishment of debt (1,192 ) — Income before income tax expense and equity in earnings of an investee 89,787 66,764 Income tax expense (446 ) (466 ) Equity in earnings of an investee 882 608 Net income 90,223 66,906 Net income allocated to noncontrolling interest (15,841 ) — Net income attributed to SIR $ 74,382 $ 66,906 Weighted average common shares outstanding (basic) 89,395 89,351 Weighted average common shares outstanding (diluted) 89,411 89,370 Net income attributed to SIR per common share (basic and diluted) $ 0.83 $ 0.75

Discontinued Operations (Tables

Discontinued Operations (Tables)	12 Months Ended
	Dec. 31, 2019
Discontinued Operations and Disposal Groups [Abstract]
Schedule of Discontinued Operations	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). Date of Sale Number of Properties Location Square Feet Gross Sale Price (1) Gain (Loss) on Sale of Real Estate Loss on Impairment of Real Estate February 2019 34 Northern Virginia and Maryland 1,635,868 $ 198,500 $ — $ 732 March 2019 1 Washington, D.C. 129,035 70,000 22,075 — May 2019 1 Buffalo, NY 121,711 16,900 — 5,137 May 2019 1 Maynard, MA 287,037 5,000 (227 ) — June 2019 1 Kapolei, HI 416,956 7,100 — — July 2019 1 San Jose, CA 71,750 14,000 (270 ) — July 2019 1 Nashua, NH 321,800 25,000 8,401 — August 2019 1 Arlington, TX 182,630 14,900 187 — August 2019 1 Rochester, NY 94,800 4,765 (104 ) — August 2019 1 Hanover, PA 502,300 5,500 (417 ) — August 2019 1 San Antonio, TX 618,017 198,000 3,869 — September 2019 1 Topeka, KS 143,934 15,600 36 — September 2019 1 Falling Waters, WV 40,348 650 — 2,179 September 2019 1 San Diego, CA 43,918 8,950 3,062 — October 2019 3 Columbia, SC 180,703 10,750 — 3,581 November 2019 3 Metro DC - MD 372,605 61,938 1,177 — December 2019 1 San Diego, CA 148,488 23,750 6,823 — December 2019 1 Phoenix, AZ 122,646 12,850 860 — December 2019 1 Houston, TX 497,477 130,000 59,992 — December 2019 1 Kansas City, KS 170,817 11,700 — 1,172 December 2019 1 San Jose, CA 75,621 13,000 (333 ) — 58 6,178,461 $ 848,853 $ 105,131 $ 12,801 (1) Gross sale price is the gross contract price, includes purchase price adjustments, if any, and excludes closing costs. As of December 31, 2019, we had six properties with an aggregate undepreciated carrying value of $61,900 under agreements to sell, as presented in the following table. We have classified these properties as held for sale in our consolidated balance sheet at December 31, 2019. Date of Sale Agreement Number of Properties Location Square Feet Gross Sale Price (1) October 2019 (2) 2 Stafford, VA 64,656 $ 14,063 October 2019 1 Fairfax, VA 83,130 22,200 October 2019 (2) 1 Windsor, CT 97,256 7,000 November 2019 (3) 1 Trenton, NJ 267,025 30,100 November 2019 1 Lincolnshire, IL 222,717 12,000 6 734,784 $ 85,363 (1) Gross sale price is the gross contract price, includes purchase price adjustments, if any, and excludes closing costs. (2) The sale of these properties was completed in January 2020. (3) We recorded a $9,454 loss on impairment of real estate during the year ended December 31, 2019 to adjust the carrying value of this property to its estimated fair value less costs to sell. Date of Sale Number of Properties Location Square Feet Gross Sale Price (1) Gain on Sale of Real Estate Loss on Impairment of Real Estate March 2018 1 Minneapolis, MN 193,594 $ 20,000 $ — $ 640 May 2018 1 New York, NY 187,060 118,500 17,249 — May 2018 1 Sacramento, CA 110,500 10,755 — 3,029 November 2018 1 Golden, CO 43,231 4,000 54 — December 2018 15 Southern Virginia 1,640,252 167,000 3,358 — 19 2,174,637 $ 320,255 $ 20,661 $ 3,669 (1) Gross sale price is the gross contract price, includes purchase price adjustments, if any, and excludes closing costs. Summarized income statement information for this property is as follows: Statements of Income (Loss) Year Ended December 31, 2017 Rental income $ 17 Real estate taxes (88 ) Utility expenses (97 ) Other operating expenses (202 ) General and administrative (76 ) Increase in carrying value of property included in discontinued operations 619 Income from discontinued operations $ 173 The following table presents the components of income from discontinued operations for the years ended December 31, 2019, 2018 and 2017: Year Ended December 31, 2019 2018 2017 Equity in earnings of Select Income REIT $ — $ 24,358 $ 21,584 Net gain on issuance of shares by Select Income REIT — 29 72 Loss on sale of Select Income REIT shares — (18,665 ) — Income from property discontinued operations — — 173 Income from discontinued operations $ — $ 5,722 $ 21,829

Selected Quarterly Financial _2

Selected Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2019
Quarterly Financial Information Disclosure [Abstract]
Schedule of Quarterly Financial Information	The following is a summary of our unaudited quarterly results of operations for 2019 and 2018 . 2019 First Quarter Second Quarter Third Quarter Fourth Quarter Rental income $ 174,777 $ 176,032 $ 167,411 $ 160,184 Net income (loss) available for common shareholders $ 34,019 $ (64,774 ) $ (3,939 ) $ 65,029 Net income (loss) available for common shareholders per common share (basic and diluted) $ 0.71 $ (1.35 ) $ (0.08 ) $ 1.35 Common distributions declared $ 0.55 $ 0.55 $ 0.55 $ 0.55 2018 First Second Third Fourth Rental income $ 108,717 $ 108,085 $ 106,102 $ 103,656 Net income (loss) available for common shareholders $ 6,287 $ 29,602 $ (449 ) $ (57,695 ) Net income (loss) available for common shareholders per common share (basic and diluted) $ 0.25 $ 1.20 $ (0.02 ) $ (2.31 ) Common distributions declared $ 1.72 $ 1.72 $ 1.72 $ 1.72

Organization (Details)

Organization (Details) $ / shares in Units, $ in Thousands, ft² in Millions	Dec. 31, 2018USD ($)ft²$ / sharesshares	Dec. 27, 2018shares	Oct. 09, 2018USD ($)$ / sharesshares	Oct. 02, 2017USD ($)ft²propertyjoint_venture	Jul. 05, 2017$ / sharesshares	Dec. 31, 2019USD ($)ft²propertystatejoint_venture	Dec. 31, 2018USD ($)ft²property$ / sharesshares	Dec. 31, 2017USD ($)
Real Estate Properties [Line Items]
Number of joint ventures | joint_venture						2
Proceeds from sale of The RMR Group Inc. common shares, net						$ 104,674	$ 0	$ 0
Stock split conversion ratio	0.25
Continuing Operations
Real Estate Properties [Line Items]
Number of properties | property						189
Number of states in which owned properties located | state						35
Rentable area of properties (in square feet) | ft²						25.7
First Potomac Realty Trust
Real Estate Properties [Line Items]
Rentable area of properties (in square feet) | ft²				6		0.4
Number of properties acquired | property				72
Total consideration transferred and liabilities assumed				$ 1,370,888
Liabilities assumed				$ 483,000
SIR
Real Estate Properties [Line Items]
Rentable area of properties (in square feet) | ft²	16.5						16.5
Number of properties acquired | property							99
Share price (in dollars per share) | $ / shares	$ 6.87						$ 6.87
Total consideration transferred and liabilities assumed							$ 2,409,740
Transaction costs	$ 27,497						27,497
Payment transaction costs	$ 14,508
Liabilities assumed							$ 1,719,772
Share conversion ratio (in shares) | shares	1.04						1.04
Common Shares | SIR
Real Estate Properties [Line Items]
Share price (in dollars per share) | $ / shares	$ 27.48						$ 27.48
Underwritten Public Offering
Real Estate Properties [Line Items]
Number of shares sold (in shares) | shares					6,250,000
Sale of stock (in dollars per share) | $ / shares					$ 74
Underwritten Public Offering | Common Shares
Real Estate Properties [Line Items]
Number of shares sold (in shares) | shares			24,918,421
Sale of stock (in dollars per share) | $ / shares			$ 18.25
Proceeds from sale of The RMR Group Inc. common shares, net			$ 435,125
First Potomac Realty Trust
Real Estate Properties [Line Items]
Number of properties | property				3		3
Number of joint ventures | joint_venture				2		2
First Potomac Realty Trust | First Potomac Realty Trust
Real Estate Properties [Line Items]
Rentable area of properties (in square feet) | ft²				0.4
SIR
Real Estate Properties [Line Items]
Payment transaction costs	$ 12,989
Joint Venture Property 1
Real Estate Properties [Line Items]
Percentage of ownership interest						50.00%
Joint Venture Property 1 | First Potomac Realty Trust
Real Estate Properties [Line Items]
Percentage of ownership interest				50.00%		51.00%
Joint Venture Property 2
Real Estate Properties [Line Items]
Percentage of ownership interest						51.00%
Joint Venture Property 2 | First Potomac Realty Trust
Real Estate Properties [Line Items]
Percentage of ownership interest				51.00%		50.00%
Industrial Logistics Properties Trust | SIR
Real Estate Properties [Line Items]
Shares owned (in shares) | shares		45,000,000

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Real Estate Properties, Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Real Estate [Line Items]
Net decreases to rental income from amortization of capitalized above market and below market leases	$ 2,710	$ 2,903	$ 2,764
Amortization of the value of leases	$ 197,978	94,375	56,174
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	5 years 9 months 18 days
Above Market Lease | Weighted Average
Real Estate [Line Items]
Acquired lease amortization period	4 years 8 months 12 days
Original Value Lease
Real Estate [Line Items]
Amortization of the value of leases	$ 195,268	$ 91,472	$ 53,410
Original Value Lease | Weighted Average
Real Estate [Line Items]
Acquired lease amortization period	6 years 2 months 12 days
Continuing Operations
Projected future amortization of net intangible lease assets and liabilities, excluding those classified as discontinued operations
2020	$ 162,586
2021	135,002
2022	118,465
2023	97,087
2024	71,836
Thereafter	$ 134,231

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Schedule of Real Estate Assets and Obligations (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Real Estate [Line Items]
Acquired real estate leases, net	$ 732,382	$ 1,056,558
Capitalized below market lease values	28,118	31,091
Less: accumulated amortization	(14,943)	(11,060)
Assumed real estate lease obligations, net	13,175	20,031
Above Market Lease
Real Estate [Line Items]
Real estate leases	61,971	62,260
Less: accumulated amortization	(29,927)	(20,956)
Acquired real estate leases, net	32,044	41,304
Original Value Lease
Real Estate [Line Items]
Real estate leases	1,032,769	1,168,979
Less: accumulated amortization	(332,431)	(153,725)
Acquired real estate leases, net	$ 700,338	$ 1,015,254

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, 2019	Dec. 31, 2018
Future amortization of deferred leasing costs, excluding those classified as discontinued operations
Deferred financing fees, net	$ 10,631	$ 12,888
Future amortization of deferred financing fees
2020	1,948
2021	1,934
2022	1,703
2023	407
2024	344
Thereafter	7,361
Continuing Operations
Debt Instrument [Line Items]
Deferred leasing costs, gross	55,716	38,840
Accumulated amortization of deferred leasing costs	15,609	13,168
Future amortization of deferred leasing costs, excluding those classified as discontinued operations
2020	5,949
2021	5,419
2022	4,591
2023	3,973
2024	3,536
Thereafter	16,639
Unsecured Revolving Credit Facility
Future amortization of deferred leasing costs, excluding those classified as discontinued operations
Deferred financing fees, gross	4,125
Accumulated amortization of deferred financing fees	$ 1,059	$ 49

Summary of Significant Accoun_7

Summary of Significant Accounting Policies - Mortgage Notes Receivable (Details) - Real Estate Loan - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Jul. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable	$ 3,600	$ 3,600	$ 3,600
Minimum interest rate			5.00%
LIBOR
Accounts, Notes, Loans and Financing Receivable [Line Items]
Basis spread on variable rate			4.00%

Summary of Significant Accoun_8

Summary of Significant Accounting Policies - Equity Securities (Details) - USD ($) $ in Thousands	Jul. 01, 2019	Dec. 31, 2018	Aug. 03, 2017
Related Party Transaction [Line Items]
Sale of stock, consideration received on transaction			$ 493,866
Class A Common Shares | RMR Inc
Related Party Transaction [Line Items]
Common shares owned in RMR Inc. (in shares)		2,801,060
Shares acquired (in shares)		1,586,836
IPO | RMR Inc
Related Party Transaction [Line Items]
Sale of stock, consideration received on transaction	$ 104,674

Summary of Significant Accoun_9

Summary of Significant Accounting Policies - Additional Information (Details) $ / shares in Units, $ in Thousands	Oct. 02, 2017propertyjoint_venture	Jun. 05, 2015USD ($)shares	Dec. 31, 2019USD ($)segmentpropertyjoint_venture$ / sharesshares	Dec. 31, 2018USD ($)$ / sharesshares	Dec. 31, 2017USD ($)shares
Schedule of Equity Method Investments [Line Items]
Number of joint ventures | joint_venture			2
Unamortized discount (premium), net			$ 17,406
Future amortization of liability			1,087
Amortization of liability thereafter			11,971
Increase in rental income to record revenue on straight line basis			27,507	$ 10,164	$ 5,582
Rental income			91,076	45,261	30,998
Tenant reimbursements received			$ 86,353	$ 40,764	$ 27,146
Common shares of beneficial interest, par value (in dollars per share) | $ / shares			$ 0.01	$ 0.01
Antidilutive securities (in shares) | shares			12	4	5
Number of business segments | segment			1
First Potomac Realty Trust
Schedule of Equity Method Investments [Line Items]
Number of joint ventures | joint_venture	2		2
Number of properties | property	3		3
Joint Venture Property 1
Schedule of Equity Method Investments [Line Items]
Percentage of ownership interest			50.00%
Joint Venture Property 1 | First Potomac Realty Trust
Schedule of Equity Method Investments [Line Items]
Percentage of ownership interest	50.00%		51.00%
Joint Venture Property 2
Schedule of Equity Method Investments [Line Items]
Percentage of ownership interest			51.00%
Joint Venture Property 2 | First Potomac Realty Trust
Schedule of Equity Method Investments [Line Items]
Percentage of ownership interest	51.00%		50.00%
Unconsolidated Joint Ventures
Schedule of Equity Method Investments [Line Items]
Number of properties | property			3
Mortgage indebtedness			$ 82,000
Continuing Operations
Schedule of Equity Method Investments [Line Items]
Number of properties | property			189
Increase in rental income to record revenue on straight line basis			$ 27,507	$ 10,164	$ 5,582
Straight line rent receivables			54,837	34,006
RMR Inc
Schedule of Equity Method Investments [Line Items]
Equity investment shares acquired (in shares) | shares		1,541,201
Payments to acquire equity securities		$ 17,462
Equity securities		$ 39,833
Amortization of liability			1,087	$ 1,087	$ 1,087
Amortization of liability, year two			1,087
Related Party Transaction Amortization Of Liability, Year Three			1,087
Related Party Transaction Amortization Of Liability, Year Four			1,087
Related Party Transaction Amortization Of Liability, Year Five			$ 1,087
Tenant Concentration
Schedule of Equity Method Investments [Line Items]
2020			4.80%
2021			1.60%
2022			2.70%
2023			1.10%
2024			2.00%
2025			5.20%
2026			2.60%
2027			1.10%
2028			2.60%
2030			0.80%
2034			0.20%
Government Tenants, All Other | Tenant Concentration
Schedule of Equity Method Investments [Line Items]
Concentration risk, percentage			6.70%
13 Government Tenants | Tenant Concentration
Schedule of Equity Method Investments [Line Items]
Concentration risk, percentage			6.40%

Summary of Significant Accou_10

Summary of Significant Accounting Policies - Operating Lease Maturity (Details) $ in Thousands	Dec. 31, 2019USD ($)
Accounting Policies [Abstract]
2020	$ 489,420
2021	466,210
2022	428,149
2023	381,164
2024	313,456
Thereafter	1,052,669
Total	$ 3,131,068

Summary of Significant Accou_11

Summary of Significant Accounting Policies - Right of Use Asset and Lease Liability (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Lessee, Lease, Description [Line Items]
2020	$ 489,420
2021	466,210
Total	3,131,068
Corporate Headquarters
Lessee, Lease, Description [Line Items]
Right-of-use asset	2,149
Lease expense	1,670
Lease expense		$ 1,707	$ 374
2020	2,049
2021	175
Total	2,224
Present value of lease liabilities	(45)
Operating lease, liability	$ 2,179

Real Estate Properties - Narrat

Real Estate Properties - Narrative (Details) $ in Thousands	Oct. 02, 2017USD ($)ft²propertyjoint_venture	Jan. 31, 2020USD ($)	Nov. 30, 2019USD ($)	Feb. 28, 2018USD ($)ft²	Oct. 31, 2017USD ($)ft²property	Sep. 30, 2017USD ($)	Aug. 31, 2017USD ($)ft²property	Dec. 31, 2019USD ($)ft²property	Sep. 30, 2019USD ($)	Jun. 30, 2019USD ($)	Mar. 31, 2019USD ($)	Dec. 31, 2018USD ($)ft²property	Sep. 30, 2018USD ($)	Jun. 30, 2018USD ($)	Mar. 31, 2018USD ($)	Dec. 31, 2019USD ($)ft²propertyjoint_venturelease	Dec. 31, 2018USD ($)ft²property	Dec. 31, 2017USD ($)ft²property	Dec. 31, 2017USD ($)ft²	Dec. 31, 2017USD ($)ft²
Real Estate Properties [Line Items]
Carrying value								$ 3,555,131								$ 3,555,131
Number of properties, noncontrolling interest | property																2
Number of leases entered | lease																107
Rentable square feet (in sqft) | ft²																2,900,000
Weighted average lease term																8 years 7 months 6 days
Expenditures committed on leases																$ 77,541
Operating leases committed expenditures on leases executed in period committed but unspent tenant related obligations								55,984								$ 55,984
Number of joint ventures | joint_venture																2
Revenues								160,184	$ 167,411	$ 176,032	$ 174,777	$ 103,656	$ 106,102	$ 108,085	$ 108,717	$ 678,404	$ 426,560		$ 316,532
Loss on impairment of real estate																22,255	8,630		9,490
Real estate properties, net								$ 3,105,575				$ 3,569,489				$ 3,105,575	$ 3,569,489
Continuing Operations
Real Estate Properties [Line Items]
Number of properties owned | property								189								189
Area of properties (in square feet) | ft²								25,700,000								25,700,000
Number of Properties | property								189								189
SIR
Real Estate Properties [Line Items]
Area of properties (in square feet) | ft²												16,500,000					16,500,000
Number of properties acquired | property																	99
Total consideration transferred and liabilities assumed																	$ 2,409,740
Payments to acquire business, gross																	8
Liabilities assumed																	1,719,772
First Potomac Realty Trust
Real Estate Properties [Line Items]
Area of properties (in square feet) | ft²	6,000,000							400,000								400,000
Number of properties acquired | property	72
Total consideration transferred and liabilities assumed	$ 1,370,888
Payments to acquire business, gross	1,175,140
Liabilities assumed	483,000
Long term debt acquired	167,936
Mortgages | SIR
Real Estate Properties [Line Items]
Long term debt acquired												$ 159,490					$ 159,490
FPO Mortgage | Mortgages | First Potomac Realty Trust
Real Estate Properties [Line Items]
Long term debt acquired	167,548
Joint Venture Mortgage | Mortgages | First Potomac Realty Trust
Real Estate Properties [Line Items]
Long term debt acquired	$ 82,000
Disposal Group, Held-for-sale
Real Estate Properties [Line Items]
Number of properties owned | property												34					34
Carrying value								$ 61,900								$ 61,900
Loss on impairment of real estate																	$ 2,830
Disposal Group, Disposed of by Sale
Real Estate Properties [Line Items]
Number of properties owned | property								58				19				58	19
Area of properties (in square feet) | ft²								6,178,461				2,200,000				6,178,461	2,200,000
Number of Properties | property								58								58
Purchase price																$ 848,853
Aggregate sale price of properties sold, excluding closing costs																848,853	$ 320,255
Loss on impairment of real estate																$ 12,801
Office Property | One Property | Disposal Group, Disposed of by Sale
Real Estate Properties [Line Items]
Area of properties (in square feet) | ft²												2,174,637					2,174,637
Number of Properties | property												19					19
Aggregate sale price of properties sold, excluding closing costs																	$ 320,255
Loss on impairment of real estate																	3,669
Safford, AZ | Disposal Group, Disposed of by Sale
Real Estate Properties [Line Items]
Area of properties (in square feet) | ft²				36,139
Aggregate sale price of properties sold, excluding closing costs				$ 8,250
Loss on impairment of real estate															$ 2,453		$ 322
Albuquerque, NM | Office Property | One Property | Disposal Group, Disposed of by Sale
Real Estate Properties [Line Items]
Number of properties owned | property					1
Area of properties (in square feet) | ft²					29,045
Aggregate sale price of properties sold, excluding closing costs					$ 2,000
Loss on impairment of real estate																			230
Real estate properties, net					$ 1,885
Falls Church, VA
Real Estate Properties [Line Items]
Number of properties owned | property							1
Area of properties (in square feet) | ft²							164,746
Real estate properties, net							$ 12,901
Falls Church, VA | Office Property | One Property | Discontinued Operations
Real Estate Properties [Line Items]
Area of properties (in square feet) | ft²							200,000
Aggregate sale price of properties sold, excluding closing costs							$ 13,523
Real estate properties, net							$ 12,901
Increase the carrying value of property																			$ (619)
Boston, MA
Real Estate Properties [Line Items]
Purchase price			$ 2,900
Manassas, VA
Real Estate Properties [Line Items]
Area of properties (in square feet) | ft²																		69,374	69,374	69,374
Purchase price																			$ 12,657
Percentage of property lease																				100.00%
Capitalized transaction costs																		$ 37	$ 37	$ 37
Manassas, VA | Office Property
Real Estate Properties [Line Items]
Number of properties acquired																		1		1
Washington, D.C. | Transferable Development Rights
Real Estate Properties [Line Items]
Payments to acquire intangible assets						$ 2,030
Joint Venture Property 1
Real Estate Properties [Line Items]
Percentage of ownership interest								50.00%								50.00%
Joint Venture Property 2
Real Estate Properties [Line Items]
Percentage of ownership interest								51.00%								51.00%
Unconsolidated Joint Ventures
Real Estate Properties [Line Items]
Number of properties owned | property								3								3
Area of properties (in square feet) | ft²								443,867								443,867
Number of Properties | property								3								3
Equity method investment, difference between carrying amount and underlying equity								$ 7,951								$ 7,951
Above Market Lease
Real Estate Properties [Line Items]
Acquired finite-lived intangible assets, weighted average useful life	3 years 2 months 12 days																5 years 9 months 18 days
Lease Agreements
Real Estate Properties [Line Items]
Acquired finite-lived intangible assets, weighted average useful life	3 years 1 month 6 days																7 years 2 months 12 days
Capitalized Below Market Leases
Real Estate Properties [Line Items]
Below market, acquired lease amortization period	3 years 9 months 18 days																5 years 8 months 12 days
First Potomac Realty Trust
Real Estate Properties [Line Items]
Number of joint ventures | joint_venture	2															2
Number of Properties | property	3							3								3
First Potomac Realty Trust | First Potomac Realty Trust
Real Estate Properties [Line Items]
Area of properties (in square feet) | ft²	400,000
First Potomac Realty Trust | Joint Venture Property 1
Real Estate Properties [Line Items]
Percentage of ownership interest	50.00%							51.00%								51.00%
First Potomac Realty Trust | Joint Venture Property 2
Real Estate Properties [Line Items]
Percentage of ownership interest	51.00%							50.00%								50.00%
FPO Shareholders | First Potomac Realty Trust
Real Estate Properties [Line Items]
Payments to acquire business, gross	$ 651,696
Acquisition-related Costs
Real Estate Properties [Line Items]
Revenues																	$ (152,735)
Net income																	$ (46,237)
Subsequent Event | Boston, MA
Real Estate Properties [Line Items]
Purchase price		$ 11,500

Real Estate Properties - Summar

Real Estate Properties - Summary of Consideration Transferred and Liabilities Assumed (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Total Purchase Price (excluding acquisition costs):
Assumed working capital		$ 0	$ 25,170	$ (1,596)
Select Income REIT unsecured revolving credit facility repaid at closing	$ 7,890
SIR
Total Purchase Price (excluding acquisition costs):
Closing price of OPI common shares (in dollars per share)			$ 6.87
Cash consideration for fractional shares			$ 8
Equity issuance costs			(239)
Value of consideration transferred			639,578
Assumed working capital			50,390
Select Income REIT unsecured revolving credit facility repaid at closing			108,000
Non-cash portion of purchase price			1,770,162
Total consideration transferred and liabilities assumed			2,409,740
Senior Unsecured Notes | SIR
Total Purchase Price (excluding acquisition costs):
Assumed notes, principal balance			1,450,000
Mortgage Note Payable | SIR
Total Purchase Price (excluding acquisition costs):
Assumed notes, principal balance			$ 161,772
Common Shares | SIR
Total Purchase Price (excluding acquisition costs):
OPI common shares issued (in shares)			23,282,704
Closing price of OPI common shares (in dollars per share)			$ 27.48
Value of consideration transferred			$ 639,809

Real Estate Properties - Purcha

Real Estate Properties - Purchase Price Allocation for SIR (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Purchase Price Allocation:
Assumed working capital		$ 0	$ 25,170	$ (1,596)
Select Income REIT unsecured revolving credit facility repaid at closing	$ 7,890
SIR
Purchase Price Allocation:
Land			477,977
Buildings and improvements			956,801
Assets of properties held for sale			6,846
Acquired real estate leases			854,431
Cash			24,744
Restricted cash			476
Rents receivable			11,370
Other assets			88,658
Total assets			2,421,303
Accounts payable and other liabilities			61,289
Assumed real estate lease obligations			11,879
Due to related persons			30,120
Net assets acquired			639,578
Assumed working capital			50,390
Select Income REIT unsecured revolving credit facility repaid at closing			108,000
Consideration transferred and liabilities assumed			2,409,740
Line of Credit | SIR
Purchase Price Allocation:
Long term debt acquired			108,000
Senior Unsecured Notes | SIR
Purchase Price Allocation:
Long term debt acquired			1,410,947
Assumed mortgage notes			1,450,000
Principal balance			1,450,000
Mortgage Note Payable | SIR
Purchase Price Allocation:
Long term debt acquired			159,490
Assumed mortgage notes			161,772
Principal balance			161,772
RMR LLC | SIR
Purchase Price Allocation:
Investment at fair value			$ 84,229

Real Estate Properties - FPO Tr

Real Estate Properties - FPO Transaction (Details) - USD ($) $ / shares in Units, $ in Thousands	May 01, 2018	Oct. 02, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Total Purchase Price:
Acquisition and transaction related costs			$ 682	$ 14,508	$ 0
Acquired net working capital			$ 0	$ (25,170)	$ 1,596
Above Market Lease
Purchase Price Allocation:
Acquired finite-lived intangible assets, weighted average useful life		3 years 2 months 12 days		5 years 9 months 18 days
Lease Origination Value
Purchase Price Allocation:
Acquired finite-lived intangible assets, weighted average useful life		3 years 1 month 6 days		7 years 2 months 12 days
Capitalized Below Market Leases
Purchase Price Allocation:
Below market, acquired lease amortization period		3 years 9 months 18 days		5 years 8 months 12 days
Series A Cumulative Preferred Units
Purchase Price Allocation:
Preferred stock, dividend rate, percentage					5.50%
Preferred stock, value, outstanding					$ 20,496
Shares outstanding (in shares)	1,813,504
Redemption percentage	5.50%
Redemption price (in dollars per share)	$ 11.15
Redemption amount	$ 20,310
First Potomac Realty Trust
Total Purchase Price:
Payments to acquire business, gross		$ 1,175,140
Acquisition and transaction related costs		9,575
Value of consideration transferred		1,184,715
Preferred units of limited partnership issued		20,221
Acquired net working capital		(1,596)
Assumed mortgage notes		167,548
Non-cash portion of purchase price		186,173
Total consideration transferred and liabilities assumed		1,370,888
Purchase Price Allocation:
Land		360,909
Buildings and improvements		681,340
Acquired real estate leases		283,498
Investment in unconsolidated joint ventures		51,305
Cash		11,191
Restricted cash		1,018
Rents receivable		2,672
Other assets		3,640
Total assets		1,395,573
Mortgage notes payable		(167,936)
Assumed real estate lease obligations		(5,776)
Accounts payable and accrued expenses		(10,640)
Rents collected in advance		(1,436)
Security deposits		(4,849)
Net assets acquired		1,204,936
First Potomac Realty Trust | Mortgage Note Payable | FPO Mortgage
Purchase Price Allocation:
Mortgage notes payable		(167,548)
Fair value adjustment		388
Long-term debt, fair value		167,936
First Potomac Realty Trust | Mortgage Note Payable | Joint Venture Mortgage
Purchase Price Allocation:
Mortgage notes payable		$ (82,000)

Real Estate Properties - Summ_2

Real Estate Properties - Summary of Pro Forma Results (Details) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)$ / shares
Real Estate [Abstract]
Rental income	$ 758,596
Net loss	$ (87,240)
Net loss per common share (in dollars per share) | $ / shares	$ (1.82)

Real Estate Properties - Schedu

Real Estate Properties - Schedule of Unconsolidated Joint Ventures (Details) - Unconsolidated Joint Ventures $ in Thousands	Dec. 31, 2019USD ($)ft²property	Dec. 31, 2018USD ($)
Real Estate [Line Items]
OPI Carrying Value of Investment at December 31, | $	$ 39,756	$ 43,665
Number of properties | property	3
Square feet (in square feet) | ft²	443,867
Prosperity Metro Plaza
Real Estate [Line Items]
OPI Ownership	51.00%
OPI Carrying Value of Investment at December 31, | $	$ 22,483	23,969
Number of properties | property	2
Square feet (in square feet) | ft²	328,456
1750 H Street, NW
Real Estate [Line Items]
OPI Ownership	50.00%
OPI Carrying Value of Investment at December 31, | $	$ 17,273	$ 19,696
Number of properties | property	1
Square feet (in square feet) | ft²	115,411

Real Estate Properties - Sche_2

Real Estate Properties - Schedule of Unconsolidated Joint Venture: Mortgage Debt (Details) - Mortgages - Unconsolidated Joint Ventures - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Real Estate [Line Items]
Interest rate (as a percent)	3.93%
Principal balance	$ 82,000	$ 82,000
Prosperity Metro Plaza
Real Estate [Line Items]
Interest rate (as a percent)	4.09%
Principal balance	$ 50,000	50,000
1750 H Street, NW
Real Estate [Line Items]
Interest rate (as a percent)	3.69%
Principal balance	$ 32,000	$ 32,000

Real Estate Properties - Dispos

Real Estate Properties - Disposition Activities (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)ft²property	Dec. 31, 2018USD ($)ft²property	Dec. 31, 2017USD ($)
Real Estate Properties [Line Items]
Gain on sale of real estate	$ 105,131	$ 20,661	$ 0
Loss on impairment of real estate	$ 22,255	$ 8,630	$ 9,490
Discontinued Operations, Held-for-sale
Real Estate Properties [Line Items]
Number of properties | property	6
Rentable area of properties (in square feet) | ft²	734,784
Aggregate sale price of properties sold, excluding closing costs	$ 85,363
Discontinued Operations, Held-for-sale | Stafford, VA
Real Estate Properties [Line Items]
Number of properties | property	2
Rentable area of properties (in square feet) | ft²	64,656
Aggregate sale price of properties sold, excluding closing costs	$ 14,063
Discontinued Operations, Held-for-sale | Fairfax, VA
Real Estate Properties [Line Items]
Number of properties | property	1
Rentable area of properties (in square feet) | ft²	83,130
Aggregate sale price of properties sold, excluding closing costs	$ 22,200
Discontinued Operations, Held-for-sale | Windsor, CT
Real Estate Properties [Line Items]
Number of properties | property	1
Rentable area of properties (in square feet) | ft²	97,256
Aggregate sale price of properties sold, excluding closing costs	$ 7,000
Discontinued Operations, Held-for-sale | Trenton, NJ
Real Estate Properties [Line Items]
Number of properties | property	1
Rentable area of properties (in square feet) | ft²	267,025
Aggregate sale price of properties sold, excluding closing costs	$ 30,100
Loss on impairment of real estate	$ 9,454
Discontinued Operations, Held-for-sale | Lincolnshire, IL
Real Estate Properties [Line Items]
Number of properties | property	1
Rentable area of properties (in square feet) | ft²	222,717
Aggregate sale price of properties sold, excluding closing costs	$ 12,000
Disposal Group, Disposed of by Sale
Real Estate Properties [Line Items]
Number of properties | property	58
Rentable area of properties (in square feet) | ft²	6,178,461	2,200,000
Aggregate sale price of properties sold, excluding closing costs	$ 848,853	$ 320,255
Gain on sale of real estate	105,131
Loss on impairment of real estate	$ 12,801
Disposal Group, Disposed of by Sale | One Property | Office Property
Real Estate Properties [Line Items]
Number of properties | property		19
Rentable area of properties (in square feet) | ft²		2,174,637
Aggregate sale price of properties sold, excluding closing costs		$ 320,255
Gain on sale of real estate		20,661
Loss on impairment of real estate		$ 3,669
Disposal Group, Disposed of by Sale | Northern Virginia and Maryland
Real Estate Properties [Line Items]
Number of properties | property	34
Rentable area of properties (in square feet) | ft²	1,635,868
Aggregate sale price of properties sold, excluding closing costs	$ 198,500
Gain on sale of real estate	0
Loss on impairment of real estate	$ 732
Disposal Group, Disposed of by Sale | Washington, D.C.
Real Estate Properties [Line Items]
Number of properties | property	1
Rentable area of properties (in square feet) | ft²	129,035
Aggregate sale price of properties sold, excluding closing costs	$ 70,000
Gain on sale of real estate	22,075
Loss on impairment of real estate	$ 0
Disposal Group, Disposed of by Sale | Buffalo, NY
Real Estate Properties [Line Items]
Number of properties | property	1
Rentable area of properties (in square feet) | ft²	121,711
Aggregate sale price of properties sold, excluding closing costs	$ 16,900
Gain on sale of real estate	0
Loss on impairment of real estate	$ 5,137
Disposal Group, Disposed of by Sale | Maynard, MA
Real Estate Properties [Line Items]
Number of properties | property	1
Rentable area of properties (in square feet) | ft²	287,037
Aggregate sale price of properties sold, excluding closing costs	$ 5,000
Gain on sale of real estate	(227)
Loss on impairment of real estate	$ 0
Disposal Group, Disposed of by Sale | Kapolei, HI
Real Estate Properties [Line Items]
Number of properties | property	1
Rentable area of properties (in square feet) | ft²	416,956
Aggregate sale price of properties sold, excluding closing costs	$ 7,100
Gain on sale of real estate	0
Loss on impairment of real estate	$ 0
Disposal Group, Disposed of by Sale | Nashua, NH
Real Estate Properties [Line Items]
Number of properties | property	1
Rentable area of properties (in square feet) | ft²	321,800
Aggregate sale price of properties sold, excluding closing costs	$ 25,000
Gain on sale of real estate	8,401
Loss on impairment of real estate	$ 0
Disposal Group, Disposed of by Sale | Arlington, TX
Real Estate Properties [Line Items]
Number of properties | property	1
Rentable area of properties (in square feet) | ft²	182,630
Aggregate sale price of properties sold, excluding closing costs	$ 14,900
Gain on sale of real estate	187
Loss on impairment of real estate	$ 0
Disposal Group, Disposed of by Sale | Rochester, NY
Real Estate Properties [Line Items]
Number of properties | property	1
Rentable area of properties (in square feet) | ft²	94,800
Aggregate sale price of properties sold, excluding closing costs	$ 4,765
Gain on sale of real estate	(104)
Loss on impairment of real estate	$ 0
Disposal Group, Disposed of by Sale | Hanover, PA
Real Estate Properties [Line Items]
Number of properties | property	1
Rentable area of properties (in square feet) | ft²	502,300
Aggregate sale price of properties sold, excluding closing costs	$ 5,500
Gain on sale of real estate	(417)
Loss on impairment of real estate	$ 0
Disposal Group, Disposed of by Sale | San Antonio, TX
Real Estate Properties [Line Items]
Number of properties | property	1
Rentable area of properties (in square feet) | ft²	618,017
Aggregate sale price of properties sold, excluding closing costs	$ 198,000
Gain on sale of real estate	3,869
Loss on impairment of real estate	$ 0
Disposal Group, Disposed of by Sale | Topeka, KS
Real Estate Properties [Line Items]
Number of properties | property	1
Rentable area of properties (in square feet) | ft²	143,934
Aggregate sale price of properties sold, excluding closing costs	$ 15,600
Gain on sale of real estate	36
Loss on impairment of real estate	$ 0
Disposal Group, Disposed of by Sale | Falling Waters, WV
Real Estate Properties [Line Items]
Number of properties | property	1
Rentable area of properties (in square feet) | ft²	40,348
Aggregate sale price of properties sold, excluding closing costs	$ 650
Gain on sale of real estate	0
Loss on impairment of real estate	$ 2,179
Disposal Group, Disposed of by Sale | Columbia,SC
Real Estate Properties [Line Items]
Number of properties | property	3
Rentable area of properties (in square feet) | ft²	180,703
Aggregate sale price of properties sold, excluding closing costs	$ 10,750
Gain on sale of real estate	0
Loss on impairment of real estate	$ 3,581
Disposal Group, Disposed of by Sale | Metro DC - MD
Real Estate Properties [Line Items]
Number of properties | property	3
Rentable area of properties (in square feet) | ft²	372,605
Aggregate sale price of properties sold, excluding closing costs	$ 61,938
Gain on sale of real estate	1,177
Loss on impairment of real estate	$ 0
Disposal Group, Disposed of by Sale | Phoenix,AZ
Real Estate Properties [Line Items]
Number of properties | property	1
Rentable area of properties (in square feet) | ft²	122,646
Aggregate sale price of properties sold, excluding closing costs	$ 12,850
Gain on sale of real estate	860
Loss on impairment of real estate	$ 0
Disposal Group, Disposed of by Sale | Houston,TX
Real Estate Properties [Line Items]
Number of properties | property	1
Rentable area of properties (in square feet) | ft²	497,477
Aggregate sale price of properties sold, excluding closing costs	$ 130,000
Gain on sale of real estate	59,992
Loss on impairment of real estate	$ 0
Disposal Group, Disposed of by Sale | Kansas City, KS
Real Estate Properties [Line Items]
Number of properties | property	1
Rentable area of properties (in square feet) | ft²	170,817
Aggregate sale price of properties sold, excluding closing costs	$ 11,700
Gain on sale of real estate	0
Loss on impairment of real estate	$ 1,172
Disposal Group, Disposed of by Sale | Minneapolis, NM | One Property | Office Property
Real Estate Properties [Line Items]
Number of properties | property		1
Rentable area of properties (in square feet) | ft²		193,594
Aggregate sale price of properties sold, excluding closing costs		$ 20,000
Gain on sale of real estate		0
Loss on impairment of real estate		$ 640
Disposal Group, Disposed of by Sale | New York, NY | One Property | Office Property
Real Estate Properties [Line Items]
Number of properties | property		1
Rentable area of properties (in square feet) | ft²		187,060
Aggregate sale price of properties sold, excluding closing costs		$ 118,500
Gain on sale of real estate		17,249
Loss on impairment of real estate		$ 0
Disposal Group, Disposed of by Sale | Sacramento, CA | One Property | Office Property
Real Estate Properties [Line Items]
Number of properties | property		1
Rentable area of properties (in square feet) | ft²		110,500
Aggregate sale price of properties sold, excluding closing costs		$ 10,755
Gain on sale of real estate		0
Loss on impairment of real estate		$ 3,029
Disposal Group, Disposed of by Sale | Golden, CO | One Property | Office Property
Real Estate Properties [Line Items]
Number of properties | property		1
Rentable area of properties (in square feet) | ft²		43,231
Aggregate sale price of properties sold, excluding closing costs		$ 4,000
Gain on sale of real estate		54
Loss on impairment of real estate		$ 0
Disposal Group, Disposed of by Sale | Southern Virginia | One Property | Office Property
Real Estate Properties [Line Items]
Number of properties | property		15
Rentable area of properties (in square feet) | ft²		1,640,252
Aggregate sale price of properties sold, excluding closing costs		$ 167,000
Gain on sale of real estate		3,358
Loss on impairment of real estate		$ 0
July 2019 | Disposal Group, Disposed of by Sale | San Jose, CA
Real Estate Properties [Line Items]
Number of properties | property	1
Rentable area of properties (in square feet) | ft²	71,750
Aggregate sale price of properties sold, excluding closing costs	$ 14,000
Gain on sale of real estate	(270)
Loss on impairment of real estate	$ 0
September 2019 | Disposal Group, Disposed of by Sale | San Diego, CA
Real Estate Properties [Line Items]
Number of properties | property	1
Rentable area of properties (in square feet) | ft²	43,918
Aggregate sale price of properties sold, excluding closing costs	$ 8,950
Gain on sale of real estate	3,062
Loss on impairment of real estate	$ 0
December 2019 | Disposal Group, Disposed of by Sale | San Jose, CA
Real Estate Properties [Line Items]
Number of properties | property	1
Rentable area of properties (in square feet) | ft²	75,621
Aggregate sale price of properties sold, excluding closing costs	$ 13,000
Gain on sale of real estate	(333)
Loss on impairment of real estate	$ 0
December 2019 | Disposal Group, Disposed of by Sale | San Diego, CA
Real Estate Properties [Line Items]
Number of properties | property	1
Rentable area of properties (in square feet) | ft²	148,488
Aggregate sale price of properties sold, excluding closing costs	$ 23,750
Gain on sale of real estate	6,823
Loss on impairment of real estate	$ 0

Real Estate Properties - Income

Real Estate Properties - Income Statement Information for Disposal of Property (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income from discontinued operations	$ 0	$ 5,722	$ 21,829
Discontinued Operations, Disposed of by Sale | Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Rental income			17
Real estate taxes			(88)
Utility expenses			(97)
Other operating expenses			(202)
General and administrative			(76)
Increase in carrying value of property included in discontinued operations			619
Income from discontinued operations			$ 173

Real Estate Properties - Summ_3

Real Estate Properties - Summary of Acquisition Activities (Details) - Manassas, VA $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)ft²property	Dec. 31, 2017USD ($)ft²	Dec. 31, 2017USD ($)ft²
Real Estate Properties [Line Items]
Square feet (in square feet) | ft²	69,374	69,374	69,374
Purchase price		$ 12,657
Land	$ 1,562	1,562	$ 1,562
Building and Improvements	8,253	8,253	8,253
Other Assumed Assets	$ 2,842	$ 2,842	$ 2,842
Office Property
Real Estate Properties [Line Items]
Number of properties	1		1

Business and Property Managem_2

Business and Property Management Agreements with RMR LLC (Details) $ in Thousands	1 Months Ended	12 Months Ended
	Jan. 31, 2019USD ($)	Dec. 31, 2019USD ($)employeeagreement	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Related Party Transaction [Line Items]
Recognized amortization of the liability			$ 603	$ 603
Incentive management fee			0	0
Transaction amount			484	484
RMR LLC
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			16,381	12,464
Recognized amortization of the liability		$ 603
Management fees as percentage of gross collected rents		3.00%
Construction supervision fees as percentage of construction costs		5.00%
Reimbursement amounts	$ 462	$ 26,442	21,279	15,321
RMR LLC | Net Property Management and Construction Supervision Fees
Related Party Transaction [Line Items]
Net business management fees		21,320
Transaction amount		21,911	$ 13,989	$ 11,566
Reimbursement amounts		$ 484
RMR LLC | Transition Services
Related Party Transaction [Line Items]
Duration of transition services		120 days
Amended And Restate Business Management Agreement | RMR LLC
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		12.00%
Measurement period for incentive management fee		3 years
Percentage for limitation and adjustments of incentive management fee payable, minimum total return per share percentage change		5.00%
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 of base business management fee payable in common shares		1.50%
Amended And Restate Business Management Agreement | RMR LLC | 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
Minimum | Amended And Restate Business Management Agreement | RMR LLC
Related Party Transaction [Line Items]
Threshold amount of average market capitalization		$ 250,000
Percentage for limitation and adjustments of incentive management fee payable, total return per share percentage, reduction		2.00%
Minimum | Amended And Restate Business Management Agreement | RMR LLC | Up C Transaction
Related Party Transaction [Line Items]
Termination fee term		19 years
Maximum | Amended And Restate Business Management Agreement | RMR LLC
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		5.00%
Maximum | Amended And Restate Business Management Agreement | RMR LLC | Up C Transaction
Related Party Transaction [Line Items]
Termination fee term		20 years
RMR LLC
Related Party Transaction [Line Items]
Incentive management fee		$ 0
SIR | RMR LLC | Net Property Management and Construction Supervision Fees
Related Party Transaction [Line Items]
Transaction amount		2,185
SIR | RMR LLC | Business Management Incentive Fee
Related Party Transaction [Line Items]
Transaction amount		$ 25,817

Related Person Transactions (De

Related Person Transactions (Details) $ / shares in Units, $ in Thousands	Feb. 13, 2020USD ($)	Jul. 01, 2019USD ($)$ / sharesshares	Aug. 03, 2017USD ($)	Jun. 30, 2019USD ($)	Jun. 30, 2018USD ($)	Jun. 30, 2017USD ($)	Dec. 31, 2019USD ($)agreement	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Related Party Transaction [Line Items]
Sale of stock, consideration received on transaction			$ 493,866
Equity in net losses of investees							$ (1,259)	$ (2,269)	$ (13)
Distribution of earnings from Affiliates Insurance Company							2,438	0	0
Property Insurance Premium Expense
Related Party Transaction [Line Items]
Related party transaction							$ 190	198	91
RMR LLC
Related Party Transaction [Line Items]
Number of agreements with RMR LLC to provide management services | agreement							2
Rental income earned							$ 1,142	1,026	303
Related party transaction								16,381	12,464
AIC
Related Party Transaction [Line Items]
Amount invested in equity investee							298	8,751	8,304
Equity in unrealized gain (loss) of investees							281	516	608
Equity in net losses of investees							90	$ (69)	$ 461
AIC | Subsequent Event
Related Party Transaction [Line Items]
Distribution of earnings from Affiliates Insurance Company	$ 9,000
AIC | Property Insurance Premium Expense, June 2018
Related Party Transaction [Line Items]
Related party transaction					$ 757
AIC | Property Insurance Premium Expense, June 2017
Related Party Transaction [Line Items]
Related party transaction						$ 1,032
AIC | Property Insurance Premium Expense, June 2019
Related Party Transaction [Line Items]
Related party transaction				$ 1,211
IPO | RMR Inc
Related Party Transaction [Line Items]
Number of shares sold (in shares) | shares		2,801,060
Sale of stock (in dollars per share) | $ / shares		$ 40
Sale of stock, consideration received on transaction		$ 104,674
SIR | AIC | Property Insurance Premium Expense, June 2019
Related Party Transaction [Line Items]
Related party transaction							$ 1,666
AIC | RMR LLC
Related Party Transaction [Line Items]
Service fee percentage							3.00%
Officers and Other Employees | Common Shares | 2009 Award Plan
Related Party Transaction [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period							4 years
Officers and Other Employees | Share-based Payment Arrangement, Tranche 1 | Common Shares | 2009 Award Plan
Related Party Transaction [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage							20.00%
Officers and Other Employees | Share-based Payment Arrangement, Tranche 2 | Common Shares | 2009 Award Plan
Related Party Transaction [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage							20.00%
Officers and Other Employees | Share-based Payment Arrangement, Tranche 3 | Common Shares | 2009 Award Plan
Related Party Transaction [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage							20.00%
Officers and Other Employees | Share-based Compensation Award, Tranche 4 | Common Shares | 2009 Award Plan
Related Party Transaction [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage							20.00%
Officers and Other Employees | Share-based Compensation Award, Tranche 5 | Common Shares | 2009 Award Plan
Related Party Transaction [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage							20.00%

Concentration (Details)

Concentration (Details)	12 Months Ended
	Dec. 31, 2019propertystategovernment_tenantstate_government	Dec. 31, 2018government	Dec. 31, 2017government_tenant
Continuing Operations
Concentration Risk [Line Items]
Number of properties | property	189
Number of states in which acquired properties located | state	35
Annualized Rental Income, Excluding Properties Classified as Discontinued Operations | Virginia
Concentration Risk [Line Items]
Annualized rental income percent	15.60%
Annualized Rental Income, Excluding Properties Classified as Discontinued Operations | California
Concentration Risk [Line Items]
Annualized rental income percent	11.90%
Annualized Rental Income, Excluding Properties Classified as Discontinued Operations | District of Columbia
Concentration Risk [Line Items]
Concentration risk, percentage	24.10%
Annualized rental income percent	10.40%
Annualized Rental Income, Excluding Properties Classified as Discontinued Operations | Texas
Concentration Risk [Line Items]
Annualized rental income percent	7.90%
Annualized Rental Income, Excluding Properties Classified as Discontinued Operations | Maryland
Concentration Risk [Line Items]
Annualized rental income percent	6.60%
Annualized Rental Income, Excluding Properties Classified as Discontinued Operations | Tenant Concentration | U S Government, State Governments, and Other Governments
Concentration Risk [Line Items]
Number of state governments	11	13
Number of other governments | government_tenant	2		3
Concentration risk, percentage	35.50%	35.40%	62.60%
Annualized Rental Income, Excluding Properties Classified as Discontinued Operations | Tenant Concentration | U.S. Government
Concentration Risk [Line Items]
Concentration risk, percentage	25.00%	25.60%	43.50%

Indebtedness - Outstanding Debt

Indebtedness - Outstanding Debt (Details) - USD ($) $ in Thousands	Jan. 20, 2020	Jul. 15, 2019	Feb. 11, 2019	Dec. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Long term debt gross				$ 2,386,209	$ 3,311,262
Unamortized debt premiums, discounts and issuance costs				(45,756)	(56,372)
Total debt				$ 2,340,453	3,254,890
Senior unsecured notes, 3.600% interest rate, due in 2020
Debt Instrument [Line Items]
Interest rate (as a percent)				3.60%
Senior unsecured notes, 4.000% interest rate, due in 2022
Debt Instrument [Line Items]
Interest rate (as a percent)				4.00%
Senior unsecured notes, 4.150% interest rate, due in 2022
Debt Instrument [Line Items]
Interest rate (as a percent)				4.15%
Senior unsecured notes, 4.250% interest rate, due in 2024
Debt Instrument [Line Items]
Interest rate (as a percent)				4.25%
Senior unsecured notes, 4.500% interest rate, due in 2025
Debt Instrument [Line Items]
Interest rate (as a percent)				4.50%
Unsecured Term Loan | Unsecured term loan, due in 2020
Debt Instrument [Line Items]
Long term debt gross				$ 0	300,000
Unsecured Term Loan | Unsecured term loan, due in 2022
Debt Instrument [Line Items]
Long term debt gross				0	88,000
Repayments of debt			$ 88,000
Senior Unsecured Notes | Senior unsecured notes, 3.750% interest rate, due in 2019
Debt Instrument [Line Items]
Long term debt gross				0	$ 350,000
Repayments of debt		$ 350
Interest rate (as a percent)					3.75%
Senior Unsecured Notes | Senior unsecured notes, 3.600% interest rate, due in 2020
Debt Instrument [Line Items]
Long term debt gross				$ 400,000	$ 400,000
Interest rate (as a percent)				3.60%
Senior Unsecured Notes | Senior unsecured notes, 4.000% interest rate, due in 2022
Debt Instrument [Line Items]
Long term debt gross				$ 300,000	300,000
Interest rate (as a percent)				4.00%
Senior Unsecured Notes | Senior unsecured notes, 4.150% interest rate, due in 2022
Debt Instrument [Line Items]
Long term debt gross				$ 300,000	300,000
Interest rate (as a percent)				4.15%
Senior Unsecured Notes | Senior unsecured notes, 4.250% interest rate, due in 2024
Debt Instrument [Line Items]
Long term debt gross				$ 350,000	350,000
Interest rate (as a percent)				4.25%
Senior Unsecured Notes | Senior unsecured notes, 4.500% interest rate, due in 2025
Debt Instrument [Line Items]
Long term debt gross				$ 400,000	400,000
Interest rate (as a percent)				4.50%
Senior Unsecured Notes | Senior unsecured notes, 5.875% interest rate, due in 2046
Debt Instrument [Line Items]
Long term debt gross				$ 310,000	310,000
Interest rate (as a percent)				5.875%
Mortgage Note Payable | Mortgage note payable, 7.000% interest rate, due in 2019
Debt Instrument [Line Items]
Long term debt gross				$ 0	$ 7,939
Interest rate (as a percent)					7.00%
Mortgage Note Payable | Mortgage note payable, 5.720% interest rate, due in 2020
Debt Instrument [Line Items]
Long term debt gross				$ 32,888	$ 33,703
Interest rate (as a percent)				5.72%
Mortgage Note Payable | Mortgage note payable, 4.160% interest rate, due in 2020
Debt Instrument [Line Items]
Long term debt gross				$ 40,062	40,772
Interest rate (as a percent)				4.16%
Mortgage Note Payable | Mortgage note payable, 8.150% interest rate, due in 2021
Debt Instrument [Line Items]
Long term debt gross				$ 1,683	2,912
Interest rate (as a percent)				8.15%
Mortgage Note Payable | Mortgage note payable, 5.877% interest rate, due in 2021
Debt Instrument [Line Items]
Long term debt gross				$ 13,166	13,437
Interest rate (as a percent)				5.877%
Mortgage Note Payable | Mortgage note payable, 4.220% interest rate, due in 2022
Debt Instrument [Line Items]
Long term debt gross				$ 26,522	27,210
Interest rate (as a percent)				4.22%
Mortgage Note Payable | Mortgage note payable, 3.550% interest rate, due in 2023
Debt Instrument [Line Items]
Long term debt gross				$ 71,000	71,000
Interest rate (as a percent)				3.55%
Mortgage Note Payable | Mortgage note payable, 3.700% interest rate, due in 2023
Debt Instrument [Line Items]
Long term debt gross				$ 50,000	50,000
Interest rate (as a percent)				3.70%
Mortgage Note Payable | Mortgage note payable, 4.800% interest rate, due in 2023
Debt Instrument [Line Items]
Long term debt gross				$ 24,108	24,509
Interest rate (as a percent)				4.80%
Mortgage Note Payable | Mortgage note payable, 4.050% interest rate, due in 2030
Debt Instrument [Line Items]
Long term debt gross				$ 66,780	66,780
Interest rate (as a percent)				4.05%
Revolving credit facility, due in 2023 | Line of Credit
Debt Instrument [Line Items]
Long term debt gross				$ 0	$ 175,000
Subsequent Event | Senior Unsecured Notes | Senior unsecured notes, 3.600% interest rate, due in 2020
Debt Instrument [Line Items]
Repayments of debt	$ 400,000
Interest rate (as a percent)	3.60%
Disposal Group, Held-for-sale | Mortgage Note Payable
Debt Instrument [Line Items]
Total debt				13,128
Unamortized debt issuance expense				$ 38

Indebtedness - Narrative Inform

Indebtedness - Narrative Information (Details) $ in Thousands

Jan. 20, 2020USD ($)

Jul. 15, 2019USD ($)

Feb. 11, 2019USD ($)

Jan. 31, 2020USD ($)

Feb. 11, 2019

Mar. 31, 2019USD ($)

Aug. 23, 2019

Dec. 31, 2019USD ($)buildingextension_option

Dec. 31, 2018USD ($)

Dec. 31, 2017USD ($)

Feb. 19, 2020USD ($)

Mar. 01, 2019property

Debt Instrument [Line Items]

Principal of properties collateralized

$ 326,209

Number of properties, securing mortgage | property

1

Unsecured revolving credit facility

0

$ 175,000

Loss on early extinguishment of debt

$ (769)

(709)

$ (1,715)

Extinguishment of debt, amount

$ 7,890

Number of buildings collateralized | building

11

Book value of properties collateralized

$ 597,619

Long-term debt

2,340,453

$ 3,254,890

Unsecured Debt Loan in 2020

Debt Instrument [Line Items]

Line of credit facility, maximum borrowing capacity

$ 300

Weighted average annual interest rate

3.90%

3.40%

2.50%

Senior unsecured notes, 3.60% interest rate, due in 2020

Debt Instrument [Line Items]

Interest rate (as a percent)

3.60%

Unsecured Debt | Unsecured term loan, due in 2022

Debt Instrument [Line Items]

Line of credit facility, maximum borrowing capacity

$ 250

Weighted average annual interest rate

4.30%

3.80%

2.90%

Repayments of debt

$ 88,000

Loss on early extinguishment of debt

$ 643

Senior Unsecured Notes | 3.750% Senior Unsecured Notes Due In 2019

Debt Instrument [Line Items]

Interest rate (as a percent)

3.75%

Repayments of debt

$ 350

Senior Unsecured Notes | Senior unsecured notes, 3.60% interest rate, due in 2020

Debt Instrument [Line Items]

Interest rate (as a percent)

3.60%

SIR

Debt Instrument [Line Items]

Extinguishment of debt, amount

$ 108,000

Senior Unsecured Notes

Debt Instrument [Line Items]

Interest rate (as a percent)

3.75%

3.75%

Loss on early extinguishment of debt

$ (126)

Unsecured Revolving Credit Facility

Debt Instrument [Line Items]

Line of credit facility, maximum borrowing capacity

750,000

Principal of properties collateralized

$ 1,950,000

Maturity term of revolving credit facility | extension_option

2

Debt Instrument, optional extension period

6 months

Debt instrument, rate premium

1.10%

Commitment fee percentage

0.25%

Interest rate (as a percent)

2.70%

3.60%

Weighted average annual interest rate

3.30%

3.00%

2.40%

Unsecured revolving credit facility

$ 0

Available borrowings

750,000

Subsequent Event | Senior Unsecured Notes | 3.60% Senior Unsecured Notes

Debt Instrument [Line Items]

Repayments of debt

$ 400,000

Subsequent Event | Senior Unsecured Notes | Senior unsecured notes, 3.60% interest rate, due in 2020

Debt Instrument [Line Items]

Interest rate (as a percent)

3.60%

Repayments of debt

$ 400,000

Subsequent Event | SIR | Senior Unsecured Notes | Senior unsecured notes, 3.60% interest rate, due in 2020

Debt Instrument [Line Items]

Interest rate (as a percent)

3.60%

Subsequent Event | Unsecured Revolving Credit Facility

Debt Instrument [Line Items]

Unsecured revolving credit facility

$ 335,000

Available borrowings

$ 415,000

Liabilities of Properties Held For Sale | Mortgage Note Payable

Debt Instrument [Line Items]

Long-term debt

$ 13,166

LIBOR | Unsecured Revolving Credit Facility

Debt Instrument [Line Items]

Basis spread on variable rate

1.25%

Indebtedness - Future Principal

Indebtedness - Future Principal Payments (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Debt Disclosure [Abstract]
2020	$ 475,707
2021	14,420
2022	625,518
2023	143,784
2024	350,000
Thereafter	776,780
Total	2,386,209	$ 3,311,262
Unamortized debt premiums, discounts and issuance costs	(45,756)	(56,372)
Total debt outstanding	$ 2,340,453	$ 3,254,890

Fair Value of Assets and Liab_3

Fair Value of Assets and Liabilities - Asset Measured at Fair Value (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)property	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Fair Value of Assets and Liabilities
Loss on impairment of real estate	$ 22,255	$ 8,630	$ 9,490
Recurring
Fair Value of Assets and Liabilities
Other liability	30,100
Recurring | Level 1 inputs
Fair Value of Assets and Liabilities
Other liability	0
Recurring | Level 2 inputs
Fair Value of Assets and Liabilities
Other liability	30,100
Recurring | Level 3 inputs
Fair Value of Assets and Liabilities
Other liability	0
Trenton, NJ | Discontinued Operations, Held-for-sale
Fair Value of Assets and Liabilities
Loss on impairment of real estate	$ 9,454
Number of impaired properties | property	1,000
Costs to sell	$ 682

Fair Value of Assets and Liab_4

Fair Value of Assets and Liabilities - Financial Instruments (Details) - USD ($) $ in Thousands	Jan. 20, 2020	Dec. 31, 2019	Dec. 31, 2018
Fair Value of Financial Instruments
Senior notes		$ 2,017,379	$ 2,357,497
Mortgage notes payable		309,946	335,241
Unamortized debt premiums, discounts and issuance costs		(45,756)	(56,372)
Long-term debt		$ 2,340,453	3,254,890
Senior unsecured notes, 3.750% interest rate, due in 2019
Fair Value of Financial Instruments
Interest rate (as a percent)		3.75%
Senior unsecured notes, 3.60% interest rate, due in 2020
Fair Value of Financial Instruments
Interest rate (as a percent)		3.60%
Senior unsecured notes, 4.00% interest rate, due in 2022
Fair Value of Financial Instruments
Interest rate (as a percent)		4.00%
Senior unsecured notes, 4.15% interest rate, due in 2022
Fair Value of Financial Instruments
Interest rate (as a percent)		4.15%
Senior unsecured notes, 4.25% interest rate, due in 2024
Fair Value of Financial Instruments
Interest rate (as a percent)		4.25%
Senior unsecured notes, 4.50% interest rate, due in 2025
Fair Value of Financial Instruments
Interest rate (as a percent)		4.50%
Senior unsecured notes, 5.875% interest rate, due in 2046
Fair Value of Financial Instruments
Interest rate (as a percent)		5.875%
Carrying Amount
Fair Value of Financial Instruments
Mortgage notes payable		$ 323,074	335,241
Fair value of debt		2,340,453	2,692,738
Carrying Amount | Senior unsecured notes, 3.750% interest rate, due in 2019
Fair Value of Financial Instruments
Senior notes		0	349,239
Carrying Amount | Senior unsecured notes, 3.60% interest rate, due in 2020
Fair Value of Financial Instruments
Senior notes		399,934	399,146
Carrying Amount | Senior unsecured notes, 4.00% interest rate, due in 2022
Fair Value of Financial Instruments
Senior notes		297,657	296,735
Carrying Amount | Senior unsecured notes, 4.15% interest rate, due in 2022
Fair Value of Financial Instruments
Senior notes		297,795	296,736
Carrying Amount | Senior unsecured notes, 4.25% interest rate, due in 2024
Fair Value of Financial Instruments
Senior notes		340,018	337,736
Carrying Amount | Senior unsecured notes, 4.50% interest rate, due in 2025
Fair Value of Financial Instruments
Senior notes		381,055	377,329
Carrying Amount | Senior unsecured notes, 5.875% interest rate, due in 2046
Fair Value of Financial Instruments
Senior notes		300,920	300,576
Fair Value
Fair Value of Financial Instruments
Mortgage notes payable		331,675	336,365
Fair value of debt		2,451,248	2,665,550
Fair Value | Senior unsecured notes, 3.750% interest rate, due in 2019
Fair Value of Financial Instruments
Senior notes		0	348,903
Fair Value | Senior unsecured notes, 3.60% interest rate, due in 2020
Fair Value of Financial Instruments
Senior notes		400,048	399,146
Fair Value | Senior unsecured notes, 4.00% interest rate, due in 2022
Fair Value of Financial Instruments
Senior notes		306,096	295,047
Fair Value | Senior unsecured notes, 4.15% interest rate, due in 2022
Fair Value of Financial Instruments
Senior notes		307,221	296,736
Fair Value | Senior unsecured notes, 4.25% interest rate, due in 2024
Fair Value of Financial Instruments
Senior notes		364,602	337,736
Fair Value | Senior unsecured notes, 4.50% interest rate, due in 2025
Fair Value of Financial Instruments
Senior notes		419,578	377,329
Fair Value | Senior unsecured notes, 5.875% interest rate, due in 2046
Fair Value of Financial Instruments
Senior notes		322,028	274,288
Senior Notes and Mortgages
Fair Value of Financial Instruments
Unamortized debt premiums, discounts and issuance costs		$ (45,756)	$ (55,524)
Senior Unsecured Notes | Senior unsecured notes, 3.60% interest rate, due in 2020
Fair Value of Financial Instruments
Interest rate (as a percent)		3.60%
Senior Unsecured Notes | Senior unsecured notes, 4.00% interest rate, due in 2022
Fair Value of Financial Instruments
Interest rate (as a percent)		4.00%
Senior Unsecured Notes | Senior unsecured notes, 4.15% interest rate, due in 2022
Fair Value of Financial Instruments
Interest rate (as a percent)		4.15%
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%
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%
Disposal Group, Held-for-sale | Mortgages
Fair Value of Financial Instruments
Long-term debt		$ 13,128
Unamortized debt issuance expense		$ 38
Subsequent Event | Senior Unsecured Notes | Senior unsecured notes, 3.60% interest rate, due in 2020
Fair Value of Financial Instruments
Interest rate (as a percent)	3.60%
Repayments of debt	$ 400,000

Shareholders' Equity - Share Aw

Shareholders' Equity - Share Awards (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)installmenttrusteeshares	Dec. 31, 2018USD ($)trusteeshares	Dec. 31, 2017USD ($)trusteeshares	Dec. 31, 2016shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Issuance of shares, net | $		$ 639,783	$ 493,866
Common Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Issuance of shares, net (in shares)		23,281,738	6,976,757
Issuance of shares, net | $		$ 233	$ 70
Officers and Other Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Issuance of shares, net (in shares)	103,100	14,675	14,337
Issuance of shares, net | $	$ 3,080	$ 995	$ 1,067
2009 Award Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted (in shares)	136,100	19,925	18,837
Number of installments | installment	5
Unvested shares (in shares)	106,680	55,321	26,062	24,743
2020 (in shares)	32,677
2021 (in shares)	28,875
2022 (in shares)	24,808
2023 (in shares)	20,320
Estimated future compensation expense for the unvested shares | $	$ 3,672
Weighted average period of recognition of compensation expenses (in years)	25 months
Compensation expense | $	$ 3,088	$ 1,337	$ 1,377
Shares available for issuance under plan (in shares)	211,334
2009 Award Plan | Common Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted (in shares)	3,000
Aggregate market value of shares awarded | $	$ 270
Market value of common shares awarded to each trustee (in dollars) | $	$ 90
2009 Award Plan | Trustees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of trustees | trustee	8	6	6
Shares granted (in shares)	3,000	750	750
Aggregate market value of shares awarded | $	$ 575	$ 254	$ 392
Market value of common shares awarded to each trustee (in dollars) | $	$ 72	$ 42	$ 65
2009 Award Plan | Managing Trustee | Common Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of trustees | trustee	3
Shares granted (in shares)	750
Aggregate market value of shares awarded | $	$ 41

Shareholders' Equity - Unvested

Shareholders' Equity - Unvested Shares Activity (Details) - 2009 Award Plan - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Number of Shares
Unvested at the beginning of the period (in shares)	55,321	26,062	24,743
Granted (in shares)	136,100	19,925	18,837
Forfeited (in shares)	(1,474)	(255)	0
Vested (in shares)	(83,267)	(18,634)	(17,518)
Unvested acquired in the SIR merger (in shares)	0	28,223	0
Unvested at the end of the period (in shares)	106,680	55,321	26,062
Weighted Average Grant Date Fair Value
Unvested at the beginning of the period (in dollars per share)	$ 73.25	$ 78.24	$ 82.36
Granted (in dollars per share)	28.84	64.73	77.44
Forfeited (in dollars per share)	49.10	52.96	0
Vested (in dollars per share)	27.78	63.80	83.20
Unvested acquired in the SIR merger (in dollars per share)	0	27.48	0
Unvested at the end of the period (in dollars per share)	$ 40.16	$ 73.25	$ 78.24

Shareholders' Equity - Share Re

Shareholders' Equity - Share Repurchases/Sale of Shares (Details) - USD ($) $ / shares in Units, $ in Thousands

Jan. 16, 2020

Aug. 03, 2017

Jul. 05, 2017

Dec. 31, 2019

Sep. 30, 2019

Jun. 30, 2019

Mar. 31, 2019

Dec. 31, 2018

Sep. 30, 2018

Jun. 30, 2018

Mar. 31, 2018

Dec. 31, 2019

Dec. 31, 2018

Dec. 31, 2017

Class of Stock [Line Items]

Share repurchases (in shares)

15,588

4,984

3,590

Stock repurchase price (in dollars per share)

$ 29.76

$ 46.54

$ 73.63

Common distributions declared (in dollars per share)

$ 0.55

$ 0.55

$ 0.55

$ 0.55

$ 1.72

$ 1.72

$ 1.72

$ 1.72

Sale of stock, consideration received on transaction

$ 493,866

Underwritten Public Offering

Class of Stock [Line Items]

Number of shares sold (in shares)

6,250,000

Sale of stock (in dollars per share)

$ 74

Over-Allotment Option

Class of Stock [Line Items]

Number of shares sold (in shares)

726,757

Sale of stock (in dollars per share)

$ 74

Subsequent Event

Class of Stock [Line Items]

Common distributions declared (in dollars per share)

$ 0.55

Dividends payable

$ 26,511

Shareholders' Equity - Distribu

Shareholders' Equity - Distribution (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Equity [Abstract]
Annual Per Share Distribution (in dollars per share)	$ 2.20	$ 6.88	$ 6.88
Total Distribution	$ 105,868	$ 170,566	$ 145,209
Characterization of Distribution, Return of Capital	0.00%	68.60%	49.35%
Characterization of Distribution, Ordinary Income	100.00%	31.40%	50.65%
Characterization of Distribution, Quality Dividend	0.00%	0.00%	0.00%

Shareholders' Equity - Cumulati

Shareholders' Equity - Cumulative Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2018
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance beginning	$ 1,778,968	$ 1,330,043	$ 935,004
Adjusted balance				$ 1,330,755
Other comprehensive income before reclassifications	(110)	(3)	33,504
Amounts reclassified from cumulative other comprehensive income to net income	(196)	(37)	(34)
Other comprehensive income (loss)	(306)	(40)	33,470
Balance ending	1,705,754	1,778,968	1,330,043
Cumulative Other Comprehensive Income (Loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance beginning	106	60,427	26,957
Amounts reclassified from cumulative other comprehensive income to retained earnings				(60,281)
Adjusted balance				146
Amounts reclassified from cumulative other comprehensive income to net income	(196)
Balance ending	(200)	106	60,427
Unrealized Gain on Investment in Equity Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance beginning	0	45,116	21,074
Amounts reclassified from cumulative other comprehensive income to retained earnings				(45,116)
Adjusted balance				0
Other comprehensive income before reclassifications			24,042
Other comprehensive income (loss)			24,042
Balance ending	0	0	45,116
Equity in Unrealized Gains (Losses) of Investees
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance beginning	106	15,311	5,883
Amounts reclassified from cumulative other comprehensive income to retained earnings				(15,165)
Adjusted balance				146
Other comprehensive income before reclassifications	90	(3)	9,462
Amounts reclassified from cumulative other comprehensive income to net income	(196)	(37)	(34)
Other comprehensive income (loss)	(106)	(40)	9,428
Balance ending	0	106	15,311
Unrealized Loss on Financial Instrument
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance beginning	0	0	0
Adjusted balance				$ 0
Other comprehensive income (loss)		0
Balance ending		$ 0	$ 0
Unrealized Loss on Financial Instrument
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Other comprehensive income before reclassifications	(200)
Other comprehensive income (loss)	(200)
Balance ending	$ (200)

Shareholders' Equity - Preferre

Shareholders' Equity - Preferred Units of Limited Partnership (Details) - Series A Cumulative Preferred Units $ / shares in Units, $ in Thousands	May 01, 2018USD ($)$ / sharesshares
Class of Stock [Line Items]
Shares outstanding (in units) | shares	1,813,504
Redemption percentage	5.50%
Redemption price (in dollars per share) | $ / shares	$ 11.15
Redemption amount | $	$ 20,310

Equity Investment in Select I_3

Equity Investment in Select Income REIT (Details) - USD ($) $ in Thousands	Oct. 09, 2018	Jul. 05, 2017	Oct. 09, 2018	Sep. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Schedule of Equity Method Investments [Line Items]
Equity method investment, other than temporary impairment					$ 0	$ 15,180	$ 0
Equity in net losses of investees					(1,259)	(2,269)	(13)
Unrealized gain (loss) from investees						(40)	9,428
Distribution of earnings from Affiliates Insurance Company					2,438	0	0
Gain (loss) on issuance of shares by Select Income REIT					0	29	72
SIR
Schedule of Equity Method Investments [Line Items]
Percentage of outstanding shares owned	27.80%		27.80%
Equity in net losses of investees			$ 24,358				21,584
Unrealized gain (loss) from investees			28				8,967
Accretion of equity in earnings			3,233				2,944
Distribution of earnings from Affiliates Insurance Company			$ 38,124				$ 50,832
SIR | SIR
Schedule of Equity Method Investments [Line Items]
Equity in net losses of investees				$ 882		608
Issuance of shares, net (in shares)			63,157				59,502
Gain (loss) on issuance of shares by Select Income REIT			$ 29			$ 72
Common Shares
Schedule of Equity Method Investments [Line Items]
Issuance of shares, net (in shares)						23,281,738	6,976,757
Underwritten Public Offering
Schedule of Equity Method Investments [Line Items]
Number of shares sold (in shares)		6,250,000
Underwritten Public Offering | Common Shares
Schedule of Equity Method Investments [Line Items]
Number of shares sold (in shares)	24,918,421
Equity method investment, other than temporary impairment						$ 18,665
Discontinued Operations | SIR
Schedule of Equity Method Investments [Line Items]
Equity method investment, other than temporary impairment					0	18,665	$ 0
Equity in net losses of investees					0	24,358	21,584
Gain (loss) on issuance of shares by Select Income REIT					$ 0	$ 29	$ 72

Equity Investment in Select I_4

Equity Investment in Select Income REIT - Income Statement Information (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								9 Months Ended		12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Oct. 09, 2018	Sep. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Schedule of Equity Method Investments [Line Items]
Rental income											$ 91,076	$ 45,261	$ 30,998
Total revenues	$ 160,184	$ 167,411	$ 176,032	$ 174,777	$ 103,656	$ 106,102	$ 108,085	$ 108,717			678,404	426,560	316,532
Real estate taxes											73,717	49,708	37,942
Other operating expenses											120,943	89,610	65,349
Depreciation and amortization											289,885	162,488	109,588
Acquisition and transaction related costs											682	14,508	0
General and administrative											32,728	24,922	18,847
Loss on impairment of real estate assets											22,255	8,630	9,490
Total expenses											574,512	376,291	262,214
Gain on sale of real estate											105,131	20,661	0
Dividend income											1,960	1,337	1,216
Unrealized gain on equity securities											(44,007)	(7,552)	0
Interest income											1,045	639	1,962
Interest expense											(134,880)	(89,865)	(65,406)
Loss on early extinguishment of debt											(769)	(709)	(1,715)
Income (loss) from continuing operations before income tax expense and equity in net losses of investees											32,372	(25,220)	(9,625)
Income tax expense											(778)	(117)	(101)
Equity in net losses of investees											(1,259)	(2,269)	(13)
Net income (loss)											$ 30,335	$ (21,884)	$ 12,090
Weighted average common shares outstanding (basic) (in shares)											48,062	24,830	21,158
Weighted average common shares outstanding (diluted) (in shares)											48,062	24,830	21,158
Net income attributed to SIR per common share (basic and diluted) (in dollars per share)	$ 1.35	$ (0.08)	$ (1.35)	$ 0.71	$ (2.31)	$ (0.02)	$ 1.20	$ 0.25			$ 0.63	$ (0.90)	$ 0.56
SIR
Schedule of Equity Method Investments [Line Items]
Equity in net losses of investees									$ 24,358				$ 21,584
SIR | SIR
Schedule of Equity Method Investments [Line Items]
Rental income										$ 298,003
Rental income												$ 392,285
Tenant reimbursements and other income										60,514
Tenant reimbursements and other income												75,818
Total revenues										358,517		468,103
Real estate taxes										36,748		44,131
Other operating expenses										43,714		55,567
Depreciation and amortization										105,326		137,672
Acquisition and transaction related costs										3,796		1,075
General and administrative										47,353		54,909
Write-off of straight line rent receivable, net										10,626		12,517
Loss on asset impairment										0		4,047
Loss on impairment of real estate assets										9,706		229
Total expenses										257,269		310,147
Gain on sale of real estate										4,075		0
Dividend income										1,190		1,587
Unrealized gain on equity securities										53,159		0
Interest income										753		91
Interest expense										(69,446)		(92,870)
Loss on early extinguishment of debt										(1,192)		0
Income (loss) from continuing operations before income tax expense and equity in net losses of investees										89,787		66,764
Income tax expense										(446)		(466)
Equity in net losses of investees										882		608
Net income										90,223		66,906
Net income allocated to noncontrolling interest										(15,841)		0
Net income (loss)										$ 74,382		$ 66,906
Weighted average common shares outstanding (basic) (in shares)										89,395		89,351
Weighted average common shares outstanding (diluted) (in shares)										89,411		89,370
Net income attributed to SIR per common share (basic and diluted) (in dollars per share)										$ 0.83		$ 0.75

Discontinued Operations - Addit

Discontinued Operations - Additional Information (Details) $ in Thousands	Oct. 09, 2018shares	Jul. 05, 2017shares	Aug. 31, 2017USD ($)ft²property	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loss on impairment of Select Income REIT investment				$ 0	$ 15,180	$ 0
Net book value				$ 3,105,575	3,569,489
Falls Church, VA
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of properties | property			1
Rentable area of properties (in square feet) | ft²			164,746
Net book value			$ 12,901
Aggregate sale price of properties sold, excluding closing costs			$ 13,523
Underwritten Public Offering
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of shares sold (in shares) | shares		6,250,000
Common Shares | Underwritten Public Offering
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of shares sold (in shares) | shares	24,918,421
Loss on impairment of Select Income REIT investment					$ 18,665

Discontinued Operations - Sched

Discontinued Operations - Schedule of Discontinued Operations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Equity in earnings of Select Income REIT	$ (1,259)	$ (2,269)	$ (13)
Net gain on issuance of shares by Select Income REIT	0	29	72
Loss on sale of Select Income REIT shares	0	(15,180)	0
Income from discontinued operations	0	5,722	21,829
SIR | Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Equity in earnings of Select Income REIT	0	24,358	21,584
Net gain on issuance of shares by Select Income REIT	0	29	72
Loss on sale of Select Income REIT shares	0	(18,665)	0
Income from property discontinued operations	0	0	173
Income from discontinued operations	$ 0	$ 5,722	$ 21,829

Selected Quarterly Financial _3

Selected Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Quarterly Financial Data [Abstract]
Revenues	$ 160,184	$ 167,411	$ 176,032	$ 174,777	$ 103,656	$ 106,102	$ 108,085	$ 108,717	$ 678,404	$ 426,560	$ 316,532
Net income (loss) available for common shareholders	$ 65,029	$ (3,939)	$ (64,774)	$ 34,019	$ (57,695)	$ (449)	$ 29,602	$ 6,287	$ 30,335	$ (22,255)	$ 11,815
Net income (loss) available for common shareholders per common share (basic and diluted) (in dollars per share)	$ 1.35	$ (0.08)	$ (1.35)	$ 0.71	$ (2.31)	$ (0.02)	$ 1.20	$ 0.25	$ 0.63	$ (0.90)	$ 0.56
Common distributions declared (in dollars per share)	$ 0.55	$ 0.55	$ 0.55	$ 0.55	$ 1.72	$ 1.72	$ 1.72	$ 1.72

SCHEDULE III REAL ESTATE AND _2

SCHEDULE III REAL ESTATE AND ACCUMULATED DEPRECIATION [Schedule] (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)building	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Real estate and accumulated depreciation
Number of Properties | building	183
Encumbrances	$ 309,946
Initial Cost to Company
Land	839,889
Buildings and Equipment	2,425,029
Costs Capitalized Subsequent to Acquisition	232,838
Impairment/ Writedowns	(4,525)
Cost amount carried at Close of Period
Land	840,550
Buildings and Equipment	2,652,681
Total	3,493,231	$ 3,944,636	$ 2,975,721	$ 1,888,760
Accumulated Depreciation	$ (387,656)	$ (375,147)	$ (341,848)	$ (296,804)
Inverness Center
Real estate and accumulated depreciation
Number of Properties | building	3
Initial Cost to Company
Land	$ 5,907
Buildings and Equipment	12,098
Costs Capitalized Subsequent to Acquisition	1,372
Cost amount carried at Close of Period
Land	5,907
Buildings and Equipment	13,470
Total	19,377
Accumulated Depreciation	$ (425)
445 Jan Davis Drive
Real estate and accumulated depreciation
Number of Properties | building	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	$ (40)
4905 Moores Mill Road
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 4,592
Buildings and Equipment	36,324
Costs Capitalized Subsequent to Acquisition	1,627
Cost amount carried at Close of Period
Land	4,592
Buildings and Equipment	37,951
Total	42,543
Accumulated Depreciation	$ (1,093)
131 Clayton Street
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 920
Buildings and Equipment	9,084
Costs Capitalized Subsequent to Acquisition	216
Cost amount carried at Close of Period
Land	920
Buildings and Equipment	9,300
Total	10,220
Accumulated Depreciation	$ (1,942)
4344 Carmichael Road
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 1,374
Buildings and Equipment	11,658
Costs Capitalized Subsequent to Acquisition	233
Cost amount carried at Close of Period
Land	1,374
Buildings and Equipment	11,891
Total	13,265
Accumulated Depreciation	$ (1,752)
15451 North 28th Avenue
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 1,917
Buildings and Equipment	7,416
Costs Capitalized Subsequent to Acquisition	625
Cost amount carried at Close of Period
Land	1,917
Buildings and Equipment	8,041
Total	9,958
Accumulated Depreciation	$ (1,054)
16001 North 28th Avenue
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 3,355
Buildings and Equipment	412
Costs Capitalized Subsequent to Acquisition	44
Cost amount carried at Close of Period
Land	3,355
Buildings and Equipment	456
Total	3,811
Accumulated Depreciation	$ (14)
711 S 14th Avenue
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 460
Buildings and Equipment	11,708
Costs Capitalized Subsequent to Acquisition	790
Impairment/ Writedowns	(4,440)
Cost amount carried at Close of Period
Land	364
Buildings and Equipment	8,154
Total	8,518
Accumulated Depreciation	$ (454)
Regents Center
Real estate and accumulated depreciation
Number of Properties | building	2
Initial Cost to Company
Land	$ 4,121
Buildings and Equipment	3,042
Costs Capitalized Subsequent to Acquisition	0
Cost amount carried at Close of Period
Land	4,121
Buildings and Equipment	3,042
Total	7,163
Accumulated Depreciation	$ (149)
Campbell Place
Real estate and accumulated depreciation
Number of Properties | building	2
Initial Cost to Company
Land	$ 5,769
Buildings and Equipment	3,871
Costs Capitalized Subsequent to Acquisition	549
Cost amount carried at Close of Period
Land	5,769
Buildings and Equipment	4,420
Total	10,189
Accumulated Depreciation	$ (115)
Folsom Corporate Center
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 2,904
Buildings and Equipment	5,583
Costs Capitalized Subsequent to Acquisition	0
Cost amount carried at Close of Period
Land	2,904
Buildings and Equipment	5,583
Total	8,487
Accumulated Depreciation	$ (174)
Bayside Technology Park
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 10,784
Buildings and Equipment	648
Costs Capitalized Subsequent to Acquisition	(1)
Cost amount carried at Close of Period
Land	10,784
Buildings and Equipment	647
Total	11,431
Accumulated Depreciation	$ (21)
5045 East Butler Street
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 7,276
Buildings and Equipment	61,118
Costs Capitalized Subsequent to Acquisition	139
Cost amount carried at Close of Period
Land	7,276
Buildings and Equipment	61,257
Total	68,533
Accumulated Depreciation	$ (26,566)
10949 N. Mather Boulevard
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 562
Buildings and Equipment	16,923
Costs Capitalized Subsequent to Acquisition	916
Cost amount carried at Close of Period
Land	562
Buildings and Equipment	17,839
Total	18,401
Accumulated Depreciation	$ (2,655)
11020 Sun Center Drive
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 1,466
Buildings and Equipment	8,797
Costs Capitalized Subsequent to Acquisition	1,401
Cost amount carried at Close of Period
Land	1,466
Buildings and Equipment	10,198
Total	11,664
Accumulated Depreciation	$ (808)
100 Redwood Shores Parkway
Real estate and accumulated depreciation
Number of Properties | building	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	$ (214)
3875 Atherton Road
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 177
Buildings and Equipment	853
Costs Capitalized Subsequent to Acquisition	0
Cost amount carried at Close of Period
Land	177
Buildings and Equipment	853
Total	1,030
Accumulated Depreciation	$ (23)
801 K Street
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 4,688
Buildings and Equipment	61,994
Costs Capitalized Subsequent to Acquisition	7,087
Cost amount carried at Close of Period
Land	4,688
Buildings and Equipment	69,081
Total	73,769
Accumulated Depreciation	$ (8,306)
9815 Goethe Road
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 1,450
Buildings and Equipment	9,465
Costs Capitalized Subsequent to Acquisition	1,523
Cost amount carried at Close of Period
Land	1,450
Buildings and Equipment	10,988
Total	12,438
Accumulated Depreciation	$ (2,307)
Capitol Place
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 2,290
Buildings and Equipment	35,891
Costs Capitalized Subsequent to Acquisition	9,822
Cost amount carried at Close of Period
Land	2,290
Buildings and Equipment	45,713
Total	48,003
Accumulated Depreciation	$ (12,081)
4560 Viewridge Road
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 4,269
Buildings and Equipment	18,316
Costs Capitalized Subsequent to Acquisition	4,319
Cost amount carried at Close of Period
Land	4,347
Buildings and Equipment	22,557
Total	26,904
Accumulated Depreciation	$ (11,467)
2115 O’Nel Drive
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 12,305
Buildings and Equipment	5,062
Costs Capitalized Subsequent to Acquisition	0
Cost amount carried at Close of Period
Land	12,305
Buildings and Equipment	5,062
Total	17,367
Accumulated Depreciation	$ (140)
North First Street
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 8,311
Buildings and Equipment	4,003
Costs Capitalized Subsequent to Acquisition	188
Cost amount carried at Close of Period
Land	8,311
Buildings and Equipment	4,191
Total	12,502
Accumulated Depreciation	$ (116)
Rio Robles Drive
Real estate and accumulated depreciation
Number of Properties | building	3
Initial Cost to Company
Land	$ 23,687
Buildings and Equipment	13,698
Costs Capitalized Subsequent to Acquisition	614
Cost amount carried at Close of Period
Land	23,687
Buildings and Equipment	14,312
Total	37,999
Accumulated Depreciation	$ (403)
2450 and 2500 Walsh Avenue
Real estate and accumulated depreciation
Number of Properties | building	2
Initial Cost to Company
Land	$ 13,374
Buildings and Equipment	16,651
Costs Capitalized Subsequent to Acquisition	0
Cost amount carried at Close of Period
Land	13,374
Buildings and Equipment	16,651
Total	30,025
Accumulated Depreciation	$ (461)
3250 and 3260 Jay Street
Real estate and accumulated depreciation
Number of Properties | building	2
Initial Cost to Company
Land	$ 19,899
Buildings and Equipment	14,051
Costs Capitalized Subsequent to Acquisition	0
Cost amount carried at Close of Period
Land	19,899
Buildings and Equipment	14,051
Total	33,950
Accumulated Depreciation	$ (390)
603 San Juan Avenue
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 563
Buildings and Equipment	5,470
Costs Capitalized Subsequent to Acquisition	0
Cost amount carried at Close of Period
Land	563
Buildings and Equipment	5,470
Total	6,033
Accumulated Depreciation	$ (1,015)
350 West Java Drive
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 24,609
Buildings and Equipment	462
Costs Capitalized Subsequent to Acquisition	21
Cost amount carried at Close of Period
Land	24,609
Buildings and Equipment	483
Total	25,092
Accumulated Depreciation	$ (14)
7958 South Chester Street
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 6,682
Buildings and Equipment	7,153
Costs Capitalized Subsequent to Acquisition	105
Cost amount carried at Close of Period
Land	6,682
Buildings and Equipment	7,258
Total	13,940
Accumulated Depreciation	$ (200)
350 Spectrum Loop
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 3,650
Buildings and Equipment	7,732
Costs Capitalized Subsequent to Acquisition	86
Cost amount carried at Close of Period
Land	3,650
Buildings and Equipment	7,818
Total	11,468
Accumulated Depreciation	$ (219)
333 Inverness Drive South
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 5,711
Buildings and Equipment	4,543
Costs Capitalized Subsequent to Acquisition	0
Cost amount carried at Close of Period
Land	5,711
Buildings and Equipment	4,543
Total	10,254
Accumulated Depreciation	$ (136)
12795 West Alameda Parkway
Real estate and accumulated depreciation
Number of Properties | building	1
Encumbrances	$ 1,687
Initial Cost to Company
Land	2,640
Buildings and Equipment	23,777
Costs Capitalized Subsequent to Acquisition	1,339
Cost amount carried at Close of Period
Land	2,640
Buildings and Equipment	25,116
Total	27,756
Accumulated Depreciation	$ (6,195)
Corporate Center
Real estate and accumulated depreciation
Number of Properties | building	3
Initial Cost to Company
Land	$ 2,887
Buildings and Equipment	27,537
Costs Capitalized Subsequent to Acquisition	3,889
Cost amount carried at Close of Period
Land	2,887
Buildings and Equipment	31,426
Total	34,313
Accumulated Depreciation	$ (13,409)
11 Dupont Circle, NW
Real estate and accumulated depreciation
Number of Properties | building	1
Encumbrances	$ 64,686
Initial Cost to Company
Land	28,255
Buildings and Equipment	44,743
Costs Capitalized Subsequent to Acquisition	5,095
Cost amount carried at Close of Period
Land	28,255
Buildings and Equipment	49,838
Total	78,093
Accumulated Depreciation	$ (3,366)
1211 Connecticut Avenue, NW
Real estate and accumulated depreciation
Number of Properties | building	1
Encumbrances	$ 26,542
Initial Cost to Company
Land	30,388
Buildings and Equipment	24,667
Costs Capitalized Subsequent to Acquisition	2,168
Cost amount carried at Close of Period
Land	30,388
Buildings and Equipment	26,835
Total	57,223
Accumulated Depreciation	$ (1,793)
1401 K Street, NW
Real estate and accumulated depreciation
Number of Properties | building	1
Encumbrances	$ 24,502
Initial Cost to Company
Land	29,215
Buildings and Equipment	34,656
Costs Capitalized Subsequent to Acquisition	4,461
Cost amount carried at Close of Period
Land	29,215
Buildings and Equipment	39,117
Total	68,332
Accumulated Depreciation	$ (2,910)
20 Massachusetts Avenue
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 12,009
Buildings and Equipment	51,527
Costs Capitalized Subsequent to Acquisition	21,755
Cost amount carried at Close of Period
Land	12,223
Buildings and Equipment	73,068
Total	85,291
Accumulated Depreciation	$ (37,223)
440 First Street, NW
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 27,903
Buildings and Equipment	38,624
Costs Capitalized Subsequent to Acquisition	1,332
Cost amount carried at Close of Period
Land	27,903
Buildings and Equipment	39,956
Total	67,859
Accumulated Depreciation	$ (2,339)
625 Indiana Avenue
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 26,000
Buildings and Equipment	25,955
Costs Capitalized Subsequent to Acquisition	8,491
Cost amount carried at Close of Period
Land	26,000
Buildings and Equipment	34,446
Total	60,446
Accumulated Depreciation	$ (8,694)
840 First Street, NE
Real estate and accumulated depreciation
Number of Properties | building	1
Encumbrances	$ 33,219
Initial Cost to Company
Land	42,727
Buildings and Equipment	73,278
Costs Capitalized Subsequent to Acquisition	2,222
Cost amount carried at Close of Period
Land	42,727
Buildings and Equipment	75,500
Total	118,227
Accumulated Depreciation	$ (4,303)
10350 NW 112th Avenue
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 4,798
Buildings and Equipment	2,757
Costs Capitalized Subsequent to Acquisition	0
Cost amount carried at Close of Period
Land	4,798
Buildings and Equipment	2,757
Total	7,555
Accumulated Depreciation	$ (76)
7850 Southwest 6th Court
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 4,800
Buildings and Equipment	30,592
Costs Capitalized Subsequent to Acquisition	383
Cost amount carried at Close of Period
Land	4,800
Buildings and Equipment	30,975
Total	35,775
Accumulated Depreciation	$ (6,808)
8900 Grand Oak Circle
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 1,100
Buildings and Equipment	11,773
Costs Capitalized Subsequent to Acquisition	427
Cost amount carried at Close of Period
Land	1,100
Buildings and Equipment	12,200
Total	13,300
Accumulated Depreciation	$ (2,787)
180 Ted Turner Drive SW
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 5,717
Buildings and Equipment	20,017
Costs Capitalized Subsequent to Acquisition	295
Cost amount carried at Close of Period
Land	5,717
Buildings and Equipment	20,312
Total	26,029
Accumulated Depreciation	$ (3,747)
Corporate Square
Real estate and accumulated depreciation
Number of Properties | building	5
Initial Cost to Company
Land	$ 3,996
Buildings and Equipment	29,762
Costs Capitalized Subsequent to Acquisition	27,962
Cost amount carried at Close of Period
Land	3,996
Buildings and Equipment	57,724
Total	61,720
Accumulated Depreciation	$ (15,442)
Executive Park
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 1,521
Buildings and Equipment	11,826
Costs Capitalized Subsequent to Acquisition	4,041
Cost amount carried at Close of Period
Land	1,521
Buildings and Equipment	15,867
Total	17,388
Accumulated Depreciation	$ (6,437)
One Georgia Center
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 10,250
Buildings and Equipment	27,933
Costs Capitalized Subsequent to Acquisition	9,227
Cost amount carried at Close of Period
Land	10,250
Buildings and Equipment	37,160
Total	47,410
Accumulated Depreciation	$ (6,646)
One Primerica Parkway
Real estate and accumulated depreciation
Number of Properties | building	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	$ (636)
4712 Southpark Boulevard
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 1,390
Buildings and Equipment	19,635
Costs Capitalized Subsequent to Acquisition	118
Cost amount carried at Close of Period
Land	1,390
Buildings and Equipment	19,753
Total	21,143
Accumulated Depreciation	$ (3,653)
91-209 Kuhela Street
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 1,998
Buildings and Equipment	0
Costs Capitalized Subsequent to Acquisition	10
Cost amount carried at Close of Period
Land	1,998
Buildings and Equipment	10
Total	2,008
Accumulated Depreciation	$ 0
8305 NW 62nd Avenue
Real estate and accumulated depreciation
Number of Properties | building	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	$ (221)
1185, 1249 & 1387 S. Vinnell Way
Real estate and accumulated depreciation
Number of Properties | building	3
Initial Cost to Company
Land	$ 3,390
Buildings and Equipment	29,026
Costs Capitalized Subsequent to Acquisition	935
Cost amount carried at Close of Period
Land	3,390
Buildings and Equipment	29,961
Total	33,351
Accumulated Depreciation	$ (5,684)
2020 S. Arlington Heights
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 1,450
Buildings and Equipment	13,588
Costs Capitalized Subsequent to Acquisition	444
Cost amount carried at Close of Period
Land	1,450
Buildings and Equipment	14,032
Total	15,482
Accumulated Depreciation	$ (3,467)
400 South Jefferson Street
Real estate and accumulated depreciation
Number of Properties | building	1
Encumbrances	$ 49,299
Initial Cost to Company
Land	19,379
Buildings and Equipment	20,115
Costs Capitalized Subsequent to Acquisition	0
Cost amount carried at Close of Period
Land	19,379
Buildings and Equipment	20,115
Total	39,494
Accumulated Depreciation	$ (558)
1415 West Diehl Road
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 12,333
Buildings and Equipment	20,586
Costs Capitalized Subsequent to Acquisition	776
Cost amount carried at Close of Period
Land	12,333
Buildings and Equipment	21,362
Total	33,695
Accumulated Depreciation	$ (636)
440 North Fairway Drive
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 4,465
Buildings and Equipment	441
Costs Capitalized Subsequent to Acquisition	0
Cost amount carried at Close of Period
Land	4,465
Buildings and Equipment	441
Total	4,906
Accumulated Depreciation	$ (13)
7601 and 7635 Interactive Way
Real estate and accumulated depreciation
Number of Properties | building	2
Initial Cost to Company
Land	$ 3,337
Buildings and Equipment	14,522
Costs Capitalized Subsequent to Acquisition	26
Cost amount carried at Close of Period
Land	3,337
Buildings and Equipment	14,548
Total	17,885
Accumulated Depreciation	$ (376)
Intech Park
Real estate and accumulated depreciation
Number of Properties | building	3
Initial Cost to Company
Land	$ 4,170
Buildings and Equipment	69,759
Costs Capitalized Subsequent to Acquisition	7,050
Cost amount carried at Close of Period
Land	4,170
Buildings and Equipment	76,809
Total	80,979
Accumulated Depreciation	$ (15,777)
The Atrium at Circleport II
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 1,796
Buildings and Equipment	1,933
Costs Capitalized Subsequent to Acquisition	0
Cost amount carried at Close of Period
Land	1,796
Buildings and Equipment	1,933
Total	3,729
Accumulated Depreciation	$ (80)
7125 Industrial Road
Real estate and accumulated depreciation
Number of Properties | building	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	$ (2,074)
251 Causeway Street
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 8,130
Buildings and Equipment	17,293
Costs Capitalized Subsequent to Acquisition	3,296
Cost amount carried at Close of Period
Land	8,130
Buildings and Equipment	20,589
Total	28,719
Accumulated Depreciation	$ (4,708)
300 and 330 Billerica Road
Real estate and accumulated depreciation
Number of Properties | building	2
Initial Cost to Company
Land	$ 4,700
Buildings and Equipment	0
Costs Capitalized Subsequent to Acquisition	458
Cost amount carried at Close of Period
Land	4,700
Buildings and Equipment	458
Total	5,158
Accumulated Depreciation	$ (3)
75 Pleasant Street
Real estate and accumulated depreciation
Number of Properties | building	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	$ (7,500)
25 Newport Avenue
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 2,700
Buildings and Equipment	9,199
Costs Capitalized Subsequent to Acquisition	1,879
Cost amount carried at Close of Period
Land	2,700
Buildings and Equipment	11,078
Total	13,778
Accumulated Depreciation	$ (2,464)
One Montvale Avenue
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 1,670
Buildings and Equipment	11,035
Costs Capitalized Subsequent to Acquisition	2,693
Cost amount carried at Close of Period
Land	1,670
Buildings and Equipment	13,728
Total	15,398
Accumulated Depreciation	$ (3,101)
314 Littleton Road
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 5,691
Buildings and Equipment	8,487
Costs Capitalized Subsequent to Acquisition	41
Cost amount carried at Close of Period
Land	5,691
Buildings and Equipment	8,528
Total	14,219
Accumulated Depreciation	$ (238)
Annapolis Commerce Center
Real estate and accumulated depreciation
Number of Properties | building	2
Initial Cost to Company
Land	$ 4,057
Buildings and Equipment	7,665
Costs Capitalized Subsequent to Acquisition	370
Cost amount carried at Close of Period
Land	4,057
Buildings and Equipment	8,035
Total	12,092
Accumulated Depreciation	$ (523)
4201 Patterson Avenue
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 901
Buildings and Equipment	8,097
Costs Capitalized Subsequent to Acquisition	4,099
Impairment/ Writedowns	(85)
Cost amount carried at Close of Period
Land	892
Buildings and Equipment	12,120
Total	13,012
Accumulated Depreciation	$ (5,401)
7001 Columbia Gateway Drive
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 5,642
Buildings and Equipment	10,352
Costs Capitalized Subsequent to Acquisition	0
Cost amount carried at Close of Period
Land	5,642
Buildings and Equipment	10,352
Total	15,994
Accumulated Depreciation	$ (305)
Hillside Center
Real estate and accumulated depreciation
Number of Properties | building	2
Initial Cost to Company
Land	$ 3,437
Buildings and Equipment	4,228
Costs Capitalized Subsequent to Acquisition	576
Cost amount carried at Close of Period
Land	3,437
Buildings and Equipment	4,804
Total	8,241
Accumulated Depreciation	$ (277)
TenThreeTwenty
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 3,126
Buildings and Equipment	16,361
Costs Capitalized Subsequent to Acquisition	1,537
Cost amount carried at Close of Period
Land	3,126
Buildings and Equipment	17,898
Total	21,024
Accumulated Depreciation	$ (1,177)
3300 75th Avenue
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 4,110
Buildings and Equipment	36,371
Costs Capitalized Subsequent to Acquisition	1,513
Cost amount carried at Close of Period
Land	4,110
Buildings and Equipment	37,884
Total	41,994
Accumulated Depreciation	$ (9,310)
2115 East Jefferson Street
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 3,349
Buildings and Equipment	11,152
Costs Capitalized Subsequent to Acquisition	436
Cost amount carried at Close of Period
Land	3,349
Buildings and Equipment	11,588
Total	14,937
Accumulated Depreciation	$ (1,815)
Redland 520/530
Real estate and accumulated depreciation
Number of Properties | building	3
Initial Cost to Company
Land	$ 12,714
Buildings and Equipment	61,377
Costs Capitalized Subsequent to Acquisition	1,744
Cost amount carried at Close of Period
Land	12,714
Buildings and Equipment	63,121
Total	75,835
Accumulated Depreciation	$ (3,541)
Redland 540
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 10,740
Buildings and Equipment	17,714
Costs Capitalized Subsequent to Acquisition	6,001
Cost amount carried at Close of Period
Land	10,740
Buildings and Equipment	23,715
Total	34,455
Accumulated Depreciation	$ (1,909)
Rutherford Business Park
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 1,598
Buildings and Equipment	10,219
Costs Capitalized Subsequent to Acquisition	472
Cost amount carried at Close of Period
Land	1,598
Buildings and Equipment	10,691
Total	12,289
Accumulated Depreciation	$ (1,845)
3550 Green Court
Real estate and accumulated depreciation
Number of Properties | building	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	$ (142)
11411 E. Jefferson Avenue
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 630
Buildings and Equipment	18,002
Costs Capitalized Subsequent to Acquisition	451
Cost amount carried at Close of Period
Land	630
Buildings and Equipment	18,453
Total	19,083
Accumulated Depreciation	$ (4,402)
Rosedale Corporate Plaza
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 672
Buildings and Equipment	6,045
Costs Capitalized Subsequent to Acquisition	1,526
Cost amount carried at Close of Period
Land	672
Buildings and Equipment	7,571
Total	8,243
Accumulated Depreciation	$ (3,759)
1300 Summit Street
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 2,776
Buildings and Equipment	12,070
Costs Capitalized Subsequent to Acquisition	1,143
Cost amount carried at Close of Period
Land	2,776
Buildings and Equipment	13,213
Total	15,989
Accumulated Depreciation	$ (2,399)
2555 Grand Boulevard
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 4,085
Buildings and Equipment	51,399
Costs Capitalized Subsequent to Acquisition	472
Cost amount carried at Close of Period
Land	4,085
Buildings and Equipment	51,871
Total	55,956
Accumulated Depreciation	$ (1,408)
4241-4300 NE 34th Street
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 1,443
Buildings and Equipment	6,193
Costs Capitalized Subsequent to Acquisition	4,180
Cost amount carried at Close of Period
Land	1,780
Buildings and Equipment	10,036
Total	11,816
Accumulated Depreciation	$ (4,523)
1220 Echelon Parkway
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 440
Buildings and Equipment	25,458
Costs Capitalized Subsequent to Acquisition	258
Cost amount carried at Close of Period
Land	440
Buildings and Equipment	25,716
Total	26,156
Accumulated Depreciation	$ (4,760)
2300 and 2400 Yorkmont Road
Real estate and accumulated depreciation
Number of Properties | building	2
Initial Cost to Company
Land	$ 1,334
Buildings and Equipment	19,075
Costs Capitalized Subsequent to Acquisition	1,387
Cost amount carried at Close of Period
Land	1,334
Buildings and Equipment	20,462
Total	21,796
Accumulated Depreciation	$ (587)
18010 and 18020 Burt Street
Real estate and accumulated depreciation
Number of Properties | building	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	$ (346)
500 Charles Ewing Boulevard
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 4,808
Buildings and Equipment	26,002
Costs Capitalized Subsequent to Acquisition	0
Cost amount carried at Close of Period
Land	4,808
Buildings and Equipment	26,002
Total	30,810
Accumulated Depreciation	$ (721)
299 Jefferson Road
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 4,543
Buildings and Equipment	2,914
Costs Capitalized Subsequent to Acquisition	493
Cost amount carried at Close of Period
Land	4,543
Buildings and Equipment	3,407
Total	7,950
Accumulated Depreciation	$ (85)
One Jefferson Road
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 4,415
Buildings and Equipment	5,249
Costs Capitalized Subsequent to Acquisition	10
Cost amount carried at Close of Period
Land	4,415
Buildings and Equipment	5,259
Total	9,674
Accumulated Depreciation	$ (143)
Airline Corporate Center
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 790
Buildings and Equipment	6,400
Costs Capitalized Subsequent to Acquisition	406
Cost amount carried at Close of Period
Land	790
Buildings and Equipment	6,806
Total	7,596
Accumulated Depreciation	$ (1,253)
5000 Corporate Court
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 6,530
Buildings and Equipment	17,711
Costs Capitalized Subsequent to Acquisition	3,799
Cost amount carried at Close of Period
Land	6,530
Buildings and Equipment	21,510
Total	28,040
Accumulated Depreciation	$ (4,492)
8687 Carling Road
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 566
Buildings and Equipment	0
Costs Capitalized Subsequent to Acquisition	0
Cost amount carried at Close of Period
Land	566
Buildings and Equipment	0
Total	566
Accumulated Depreciation	$ 0
1212 Pittsford - Victor Road
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 608
Buildings and Equipment	78
Costs Capitalized Subsequent to Acquisition	530
Cost amount carried at Close of Period
Land	608
Buildings and Equipment	608
Total	1,216
Accumulated Depreciation	$ (5)
2231 Schrock Road
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 716
Buildings and Equipment	217
Costs Capitalized Subsequent to Acquisition	101
Cost amount carried at Close of Period
Land	716
Buildings and Equipment	318
Total	1,034
Accumulated Depreciation	$ (10)
4600 25th Avenue
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 6,510
Buildings and Equipment	17,973
Costs Capitalized Subsequent to Acquisition	6,658
Cost amount carried at Close of Period
Land	6,510
Buildings and Equipment	24,631
Total	31,141
Accumulated Depreciation	$ (5,904)
8800 Tinicum Boulevard
Real estate and accumulated depreciation
Number of Properties | building	1
Encumbrances	$ 40,310
Initial Cost to Company
Land	5,573
Buildings and Equipment	22,686
Costs Capitalized Subsequent to Acquisition	0
Cost amount carried at Close of Period
Land	5,573
Buildings and Equipment	22,686
Total	28,259
Accumulated Depreciation	$ (629)
9680 Old Bailes Road
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 834
Buildings and Equipment	2,944
Costs Capitalized Subsequent to Acquisition	0
Cost amount carried at Close of Period
Land	834
Buildings and Equipment	2,944
Total	3,778
Accumulated Depreciation	$ (82)
One Memphis Place
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 1,630
Buildings and Equipment	5,645
Costs Capitalized Subsequent to Acquisition	7,435
Cost amount carried at Close of Period
Land	1,630
Buildings and Equipment	13,080
Total	14,710
Accumulated Depreciation	$ (2,996)
16001 North Dallas Parkway
Real estate and accumulated depreciation
Number of Properties | building	2
Initial Cost to Company
Land	$ 10,158
Buildings and Equipment	63,036
Costs Capitalized Subsequent to Acquisition	331
Cost amount carried at Close of Period
Land	10,158
Buildings and Equipment	63,367
Total	73,525
Accumulated Depreciation	$ (1,870)
Research Park
Real estate and accumulated depreciation
Number of Properties | building	2
Initial Cost to Company
Land	$ 4,258
Buildings and Equipment	13,747
Costs Capitalized Subsequent to Acquisition	536
Cost amount carried at Close of Period
Land	4,258
Buildings and Equipment	14,283
Total	18,541
Accumulated Depreciation	$ (835)
10451 Clay Road
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 5,495
Buildings and Equipment	10,253
Costs Capitalized Subsequent to Acquisition	0
Cost amount carried at Close of Period
Land	5,495
Buildings and Equipment	10,253
Total	15,748
Accumulated Depreciation	$ (284)
202 North Castlegory Road
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 863
Buildings and Equipment	5,024
Costs Capitalized Subsequent to Acquisition	0
Cost amount carried at Close of Period
Land	863
Buildings and Equipment	5,024
Total	5,887
Accumulated Depreciation	$ (131)
6380 Rogerdale Road
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 12,628
Buildings and Equipment	6,113
Costs Capitalized Subsequent to Acquisition	14
Cost amount carried at Close of Period
Land	12,628
Buildings and Equipment	6,127
Total	18,755
Accumulated Depreciation	$ (170)
4221 W. John Carpenter Freeway
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 1,413
Buildings and Equipment	2,365
Costs Capitalized Subsequent to Acquisition	1,737
Cost amount carried at Close of Period
Land	1,413
Buildings and Equipment	4,102
Total	5,515
Accumulated Depreciation	$ (123)
8675,8701-8711 Freeport Pkwy and 8901 Esters Boulevard
Real estate and accumulated depreciation
Number of Properties | building	3
Initial Cost to Company
Land	$ 10,185
Buildings and Equipment	31,566
Costs Capitalized Subsequent to Acquisition	0
Cost amount carried at Close of Period
Land	10,185
Buildings and Equipment	31,566
Total	41,751
Accumulated Depreciation	$ (875)
1511 East Common Street
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 4,965
Buildings and Equipment	1,266
Costs Capitalized Subsequent to Acquisition	67
Cost amount carried at Close of Period
Land	4,965
Buildings and Equipment	1,333
Total	6,298
Accumulated Depreciation	$ (35)
2900 West Plano Parkway
Real estate and accumulated depreciation
Number of Properties | building	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	$ (244)
3400 West Plano Parkway
Real estate and accumulated depreciation
Number of Properties | building	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	$ (451)
3600 Wiseman Boulevard
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 3,493
Buildings and Equipment	6,662
Costs Capitalized Subsequent to Acquisition	137
Cost amount carried at Close of Period
Land	3,493
Buildings and Equipment	6,799
Total	10,292
Accumulated Depreciation	$ (194)
701 Clay Road
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 2,030
Buildings and Equipment	8,708
Costs Capitalized Subsequent to Acquisition	9,450
Cost amount carried at Close of Period
Land	2,060
Buildings and Equipment	18,128
Total	20,188
Accumulated Depreciation	$ (5,351)
1800 Novell Place
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 7,487
Buildings and Equipment	43,487
Costs Capitalized Subsequent to Acquisition	0
Cost amount carried at Close of Period
Land	7,487
Buildings and Equipment	43,487
Total	50,974
Accumulated Depreciation	$ (1,301)
4885-4931 North 300 West
Real estate and accumulated depreciation
Number of Properties | building	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	$ (276)
14660, 14672 & 14668 Lee Road
Real estate and accumulated depreciation
Number of Properties | building	3
Initial Cost to Company
Land	$ 6,966
Buildings and Equipment	74,214
Costs Capitalized Subsequent to Acquisition	2,278
Cost amount carried at Close of Period
Land	6,966
Buildings and Equipment	76,492
Total	83,458
Accumulated Depreciation	$ (5,879)
1434 Crossways
Real estate and accumulated depreciation
Number of Properties | building	2
Initial Cost to Company
Land	$ 3,617
Buildings and Equipment	19,527
Costs Capitalized Subsequent to Acquisition	2,010
Cost amount carried at Close of Period
Land	3,617
Buildings and Equipment	21,537
Total	25,154
Accumulated Depreciation	$ (1,749)
Greenbrier Towers
Real estate and accumulated depreciation
Number of Properties | building	2
Initial Cost to Company
Land	$ 3,437
Buildings and Equipment	11,241
Costs Capitalized Subsequent to Acquisition	1,457
Cost amount carried at Close of Period
Land	3,437
Buildings and Equipment	12,698
Total	16,135
Accumulated Depreciation	$ (1,080)
Enterchange at Meadowville
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 1,478
Buildings and Equipment	9,594
Costs Capitalized Subsequent to Acquisition	283
Cost amount carried at Close of Period
Land	1,478
Buildings and Equipment	9,877
Total	11,355
Accumulated Depreciation	$ (1,558)
Pender Business Park
Real estate and accumulated depreciation
Number of Properties | building	4
Initial Cost to Company
Land	$ 2,487
Buildings and Equipment	21,386
Costs Capitalized Subsequent to Acquisition	1,127
Cost amount carried at Close of Period
Land	2,487
Buildings and Equipment	22,513
Total	25,000
Accumulated Depreciation	$ (3,530)
Three Flint Hill
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 5,991
Buildings and Equipment	25,536
Costs Capitalized Subsequent to Acquisition	2,897
Cost amount carried at Close of Period
Land	5,991
Buildings and Equipment	28,433
Total	34,424
Accumulated Depreciation	$ (2,058)
7987 Ashton Avenue
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 1,562
Buildings and Equipment	8,253
Costs Capitalized Subsequent to Acquisition	694
Cost amount carried at Close of Period
Land	1,562
Buildings and Equipment	8,947
Total	10,509
Accumulated Depreciation	$ (717)
Two Commercial Place
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 4,494
Buildings and Equipment	21,508
Costs Capitalized Subsequent to Acquisition	389
Cost amount carried at Close of Period
Land	4,494
Buildings and Equipment	21,897
Total	26,391
Accumulated Depreciation	$ (563)
1759 & 1760 Business Center Drive
Real estate and accumulated depreciation
Number of Properties | building	2
Initial Cost to Company
Land	$ 9,066
Buildings and Equipment	78,658
Costs Capitalized Subsequent to Acquisition	4,093
Cost amount carried at Close of Period
Land	9,066
Buildings and Equipment	82,751
Total	91,817
Accumulated Depreciation	$ (11,392)
1775 Wiehle Avenue
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 4,138
Buildings and Equipment	26,120
Costs Capitalized Subsequent to Acquisition	1,446
Cost amount carried at Close of Period
Land	4,138
Buildings and Equipment	27,566
Total	31,704
Accumulated Depreciation	$ (1,583)
501 South 5th Street
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 14,767
Buildings and Equipment	39,101
Costs Capitalized Subsequent to Acquisition	230
Cost amount carried at Close of Period
Land	14,767
Buildings and Equipment	39,331
Total	54,098
Accumulated Depreciation	$ (1,134)
9201 Forest Hill Avenue
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 1,344
Buildings and Equipment	375
Costs Capitalized Subsequent to Acquisition	150
Cost amount carried at Close of Period
Land	1,344
Buildings and Equipment	525
Total	1,869
Accumulated Depreciation	$ (12)
9960 Mayland Drive
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 2,614
Buildings and Equipment	15,930
Costs Capitalized Subsequent to Acquisition	2,440
Cost amount carried at Close of Period
Land	2,614
Buildings and Equipment	18,370
Total	20,984
Accumulated Depreciation	$ (2,559)
Parham Place
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	15
Cost amount carried at Close of Period
Land	913
Buildings and Equipment	1,114
Total	2,027
Accumulated Depreciation	$ (31)
1751 Blue Hills Drive
Real estate and accumulated depreciation
Number of Properties | building	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	$ (215)
Atlantic Corporate Park
Real estate and accumulated depreciation
Number of Properties | building	2
Initial Cost to Company
Land	$ 5,752
Buildings and Equipment	29,316
Costs Capitalized Subsequent to Acquisition	2,055
Cost amount carried at Close of Period
Land	5,752
Buildings and Equipment	31,371
Total	37,123
Accumulated Depreciation	$ (1,690)
Orbital Sciences Campus
Real estate and accumulated depreciation
Number of Properties | building	3
Initial Cost to Company
Land	$ 12,275
Buildings and Equipment	19,320
Costs Capitalized Subsequent to Acquisition	25
Cost amount carried at Close of Period
Land	12,275
Buildings and Equipment	19,345
Total	31,620
Accumulated Depreciation	$ (570)
Sterling Business Park Lots 8 and 9
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 9,177
Buildings and Equipment	44,324
Costs Capitalized Subsequent to Acquisition	52
Cost amount carried at Close of Period
Land	9,177
Buildings and Equipment	44,376
Total	53,553
Accumulated Depreciation	$ (2,493)
65 Bowdoin Street
Real estate and accumulated depreciation
Number of Properties | building	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	$ (2,090)
840 North Broadway
Real estate and accumulated depreciation
Number of Properties | building	2
Initial Cost to Company
Land	$ 3,360
Buildings and Equipment	15,376
Costs Capitalized Subsequent to Acquisition	2,649
Cost amount carried at Close of Period
Land	3,360
Buildings and Equipment	18,025
Total	21,385
Accumulated Depreciation	$ (3,716)
Stevens Center
Real estate and accumulated depreciation
Number of Properties | building	2
Initial Cost to Company
Land	$ 3,970
Buildings and Equipment	17,035
Costs Capitalized Subsequent to Acquisition	4,456
Cost amount carried at Close of Period
Land	4,042
Buildings and Equipment	21,419
Total	25,461
Accumulated Depreciation	$ (10,658)
351, 401, 501 Elliott Ave West
Real estate and accumulated depreciation
Number of Properties | building	3
Encumbrances	$ 69,701
Initial Cost to Company
Land	26,640
Buildings and Equipment	52,740
Costs Capitalized Subsequent to Acquisition	654
Cost amount carried at Close of Period
Land	26,640
Buildings and Equipment	53,394
Total	80,034
Accumulated Depreciation	$ (1,467)
11050 West Liberty Drive
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 945
Buildings and Equipment	4,539
Costs Capitalized Subsequent to Acquisition	103
Cost amount carried at Close of Period
Land	945
Buildings and Equipment	4,642
Total	5,587
Accumulated Depreciation	$ (998)
5353 Yellowstone Road
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 1,915
Buildings and Equipment	8,217
Costs Capitalized Subsequent to Acquisition	1,346
Cost amount carried at Close of Period
Land	1,950
Buildings and Equipment	9,528
Total	11,478
Accumulated Depreciation	$ (4,907)
Total Real Estate Assets
Real estate and accumulated depreciation
Number of Properties | building	189
Encumbrances	$ 323,074
Initial Cost to Company
Land	856,105
Buildings and Equipment	2,484,677
Costs Capitalized Subsequent to Acquisition	237,497
Impairment/ Writedowns	(23,148)
Cost amount carried at Close of Period
Land	855,632
Buildings and Equipment	2,699,499
Total	3,555,131
Accumulated Depreciation	$ (391,209)
Properties Held for Sale
Real estate and accumulated depreciation
Number of Properties | building	6
Encumbrances	$ 13,128
Initial Cost to Company
Land	16,216
Buildings and Equipment	59,648
Costs Capitalized Subsequent to Acquisition	4,659
Impairment/ Writedowns	(18,623)
Cost amount carried at Close of Period
Land	15,082
Buildings and Equipment	46,818
Total	61,900
Accumulated Depreciation	$ (3,553)
Properties Held for Sale | 1 Targeting Center
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 1,428
Buildings and Equipment	588
Costs Capitalized Subsequent to Acquisition	0
Cost amount carried at Close of Period
Land	1,428
Buildings and Equipment	588
Total	2,016
Accumulated Depreciation	$ (13)
Properties Held for Sale | 475 Bond Street
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 4,764
Buildings and Equipment	552
Costs Capitalized Subsequent to Acquisition	0
Cost amount carried at Close of Period
Land	4,764
Buildings and Equipment	552
Total	5,316
Accumulated Depreciation	$ (11)
Properties Held for Sale | 50 West State Street
Real estate and accumulated depreciation
Number of Properties | building	1
Initial Cost to Company
Land	$ 5,000
Buildings and Equipment	38,203
Costs Capitalized Subsequent to Acquisition	3,337
Impairment/ Writedowns	(18,623)
Cost amount carried at Close of Period
Land	3,866
Buildings and Equipment	24,051
Total	27,917
Accumulated Depreciation	$ 0
Properties Held for Sale | 3920 Pender Drive
Real estate and accumulated depreciation
Number of Properties | building	1
Encumbrances	$ 13,128
Initial Cost to Company
Land	2,934
Buildings and Equipment	12,840
Costs Capitalized Subsequent to Acquisition	538
Cost amount carried at Close of Period
Land	2,934
Buildings and Equipment	13,378
Total	16,312
Accumulated Depreciation	$ (1,796)
Properties Held for Sale | Aquia Commerce Center
Real estate and accumulated depreciation
Number of Properties | building	2
Initial Cost to Company
Land	$ 2,090
Buildings and Equipment	7,465
Costs Capitalized Subsequent to Acquisition	784
Cost amount carried at Close of Period
Land	2,090
Buildings and Equipment	8,249
Total	10,339
Accumulated Depreciation	$ (1,733)

SCHEDULE III REAL ESTATE AND _3

SCHEDULE III REAL ESTATE AND ACCUMULATED DEPRECIATION [Schedule] - Additional Information (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation Disclosure [Abstract]
Mortgage debt, net	$ 3,135
Aggregate cost for federal income tax purposes	$ 6,971,434
Useful life of buildings and improvements	40 years
Useful life of equipment	12 years

SCHEDULE III REAL ESTATE AND _4

SCHEDULE III REAL ESTATE AND ACCUMULATED DEPRECIATION [Schedule] - Carrying Amount and Accumulated Depreciation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Real Estate Properties
Balance at the beginning of the period	$ 3,944,636	$ 2,975,721	$ 1,888,760
Additions	66,221	1,486,342	1,100,138
Loss on asset impairment	(22,255)	(8,630)	(9,490)
Disposals	(424,302)	(286,837)	(3,687)
Cost basis adjustment	(9,169)	(5,005)
Reclassification of assets of properties held for sale	(61,900)	(216,955)
Balance at the end of the period	3,493,231	3,944,636	2,975,721
Accumulated Depreciation
Balance at the beginning of the period	375,147	341,848	296,804
Additions	89,398	65,215	45,315
Loss on asset impairment	0	0	0
Disposals	(64,167)	(18,740)	(271)
Cost basis adjustment	(9,169)	(5,005)
Reclassification of assets of properties held for sale	(3,553)	(8,171)
Balance at the end of the period	$ 387,656	$ 375,147	$ 341,848

Uncategorized Items - opi123119

Label	Element	Value
Common Stock [Member]
Shares, Outstanding	us-gaap_SharesOutstanding	24,786,479
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest, Adjusted Balance	us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAdjustedBalance1	$ 248,000
Additional Paid-in Capital [Member]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest, Adjusted Balance	us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAdjustedBalance1	1,968,960,000
Retained Earnings [Member]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest, Adjusted Balance	us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAdjustedBalance1	169,137,000
Cumulative Common Distributions [Member]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest, Adjusted Balance	us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAdjustedBalance1	(807,736,000)
Accounting Standards Update 2014-09 [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	712,000
Accounting Standards Update 2014-09 [Member] | Retained Earnings [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	712,000
Accounting Standards Update 2016-01 [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	0
Accounting Standards Update 2016-01 [Member] | AOCI Attributable to Parent [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	(60,281,000)
Accounting Standards Update 2016-01 [Member] | Retained Earnings [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	$ 60,281,000