Office Properties Income Trust (OPI) 10-K 22 Feb 17 2016 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2016	Feb. 21, 2017	Jun. 30, 2016
Document and Entity Information
Entity Registrant Name	Government Properties Income Trust
Entity Central Index Key	1,456,772
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-K
Document Period End Date	Dec. 31, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Common Stock, Shares Outstanding		71,177,906
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 1.6

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Real estate properties:
Land	$ 267,855	$ 253,058
Buildings and improvements	1,620,905	1,443,074
Total real estate properties, gross	1,888,760	1,696,132
Accumulated depreciation	(296,804)	(255,879)
Total real estate properties, net	1,591,956	1,440,253
Equity investment in Select Income REIT	487,708	491,369
Assets of discontinued operations	12,541	12,468
Assets of property held for sale	0	3,098
Acquired real estate leases, net	124,848	118,267
Cash and cash equivalents	29,941	8,785
Restricted cash	530	1,022
Rents receivable, net	48,458	45,269
Deferred leasing costs, net	21,079	14,299
Other assets, net	68,005	33,680
Total assets	2,385,066	2,168,510
LIABILITIES AND SHAREHOLDERS’ EQUITY
Unsecured revolving credit facility	160,000	117,000
Unsecured term loans, net	547,171	546,490
Senior unsecured notes, net	646,844	345,809
Mortgage notes payable, net	27,837	136,299
Liabilities of discontinued operations	45	54
Liabilities of property held for sale	0	43
Accounts payable and other liabilities	54,019	50,543
Due to related persons	3,520	2,886
Assumed real estate lease obligations, net	10,626	12,735
Total liabilities	1,450,062	1,211,859
Commitments and contingencies
Shareholders’ equity:
Common shares of beneficial interest, $.01 par value: 100,000,000 shares authorized, 71,177,906 and 71,126,308 shares issued and outstanding, respectively	712	711
Additional paid in capital	1,473,533	1,472,482
Cumulative net income	96,329	38,486
Cumulative other comprehensive income (loss)	26,957	(14,867)
Cumulative common distributions	(662,527)	(540,161)
Total shareholders’ equity	935,004	956,651
Total liabilities and shareholders’ equity	$ 2,385,066	$ 2,168,510

CONDENSED CONSOLIDATED BALANCE3

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Dec. 31, 2016	Dec. 31, 2015
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	100,000,000	100,000,000
Common shares of beneficial interest, shares issued	71,177,906	71,126,308
Common shares of beneficial interest, shares outstanding	71,177,906	71,126,308

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Statement [Abstract]
Rental income	$ 258,180	$ 248,549	$ 251,031
Expenses:
Real estate taxes	30,703	29,906	28,389
Utility expenses	17,269	17,916	19,369
Other operating expenses	54,290	50,425	45,982
Depreciation and amortization	73,153	68,696	66,593
Loss on impairment of real estate	0	0	2,016
Acquisition related costs	1,191	811	1,344
General and administrative	14,897	14,826	15,809
Total expenses	191,503	182,580	179,502
Operating income	66,677	65,969	71,529
Dividend income	971	811	0
Interest income	158	14	69
Interest expense (including net amortization of debt premiums and discounts and deferred financing fees of $2,832, $1,376, and $1,310, respectively)	(45,060)	(37,008)	(28,048)
Gain (loss) on early extinguishment of debt	104	34	(1,307)
Loss on distribution to common shareholders of The RMR Group Inc. common stock	0	(12,368)	0
Net gain (loss) on issuance of shares by Select Income REIT	86	(42,145)	(53)
Loss on impairment of Select Income REIT investment	0	(203,297)	0
Income (loss) from continuing operations before income taxes and equity in earnings of investees	22,936	(227,990)	42,190
Income tax expense	(101)	(86)	(117)
Equity in earnings of investees	35,518	18,640	10,963
Income (loss) from continuing operations	58,353	(209,436)	53,036
Income (loss) from discontinued operations	(589)	(525)	3,498
Income (loss) before gain on sale of property	57,764	(209,961)	56,534
Gain on sale of property	79	0	0
Net income (loss)	57,843	(209,961)	56,534
Other comprehensive income (loss)
Unrealized gain (loss) on investment in available for sale securities	30,465	(9,391)	0
Equity in unrealized gain (loss) of investees	11,359	(5,513)	(12)
Other comprehensive income (loss)	41,824	(14,904)	(12)
Comprehensive income (loss)	$ 99,667	$ (224,865)	$ 56,522
Weighted average common shares outstanding (basic) (in shares)	71,050	70,700	61,313
Weighted average common shares outstanding (diluted) (in shares)	71,071	70,700	61,399
Per common share amounts:
Income (loss) from continuing operations (basic) (in dollars per share)	$ 0.82	$ (2.96)	$ 0.87
Income (loss) from continuing operations (diluted) (in dollars per share)	0.82	(2.96)	0.86
Income (loss) from discontinued operations (basic and diluted) (in dollars per share)	(0.01)	(0.01)	0.06
Net income (loss) (basic and diluted) (in dollars per share)	$ 0.81	$ (2.97)	$ 0.92

CONDENSED CONSOLIDATED STATEME5

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Statement [Abstract]
Net amortization of debt premiums and discounts and debt issuance costs	$ 2,832	$ 1,376	$ 1,310

CONSOLIDATED STATEMENTS OF SHAR

CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Shares	Additional Paid In Capital	Cumulative Net Income (Loss)	Cumulative Other Comprehensive Income (Loss)	Cumulative Common Distributions
Balance at Dec. 31, 2013	$ 989,675	$ 547	$ 1,105,679	$ 191,913	$ 49	$ (308,513)
Balance (in shares) at Dec. 31, 2013		54,722,018
Increase (Decrease) in Shareholders' Equity
Issuance of shares, net	350,713	$ 155	350,558
Issuance of shares, net (in shares)		15,563,559
Share grants	1,395	$ 1	1,394
Share grants (in shares)		63,650
Equity in unrealized gain (loss) of investees	(12)				(12)
Net income (loss)	56,534			56,534
Distributions to common shareholders	(100,856)					(100,856)
Balance at Dec. 31, 2014	1,297,449	$ 703	1,457,631	248,447	37	(409,369)
Balance (in shares) at Dec. 31, 2014		70,349,227
Increase (Decrease) in Shareholders' Equity
Issuance of shares, net	14,046	$ 7	14,039
Issuance of shares, net (in shares)		723,222
Share grants	985	$ 1	984
Share grants (in shares)		65,600
Share repurchases	(172)		(172)
Share repurchases (in shares)		(11,741)
Equity in unrealized gain (loss) of investees	(5,513)				(5,513)
Unrealized gain (losss) on investment in available for sale securities	(9,391)				(9,391)
Net income (loss)	(209,961)			(209,961)
Distributions to common shareholders	(130,792)					(130,792)
Balance at Dec. 31, 2015	956,651	$ 711	1,472,482	38,486	(14,867)	(540,161)
Balance (in shares) at Dec. 31, 2015		71,126,308
Increase (Decrease) in Shareholders' Equity
Share grants	1,389	$ 1	1,388
Share grants (in shares)		65,900
Share repurchases	(337)		(337)
Share repurchases (in shares)		(14,302)
Equity in unrealized gain (loss) of investees	11,359				11,359
Unrealized gain (losss) on investment in available for sale securities	30,465				30,465
Net income (loss)	57,843			57,843
Distributions to common shareholders	(122,366)					(122,366)
Balance at Dec. 31, 2016	$ 935,004	$ 712	$ 1,473,533	$ 96,329	$ 26,957	$ (662,527)
Balance (in shares) at Dec. 31, 2016		71,177,906

CONDENSED CONSOLIDATED STATEME7

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income (loss)	$ 57,843	$ (209,961)	$ 56,534
Adjustments to reconcile net income (loss) to cash provided by operating activities:
Depreciation	42,489	38,987	37,671
Net amortization of debt premiums and discounts and debt issuance costs	2,832	1,376	1,310
(Gain) loss on early extinguishment of debt	(104)	(34)	1,307
Straight line rental income	(2,691)	(3,978)	(4,495)
Amortization of acquired real estate leases	29,003	28,624	27,713
Amortization of deferred leasing costs	3,265	2,349	2,145
Other non-cash expenses, net	284	817	2,181
Loss on impairment of real estate	0	0	2,016
Increase in carrying value of asset held for sale	0	0	(2,344)
Net gain on sale of properties	(79)	0	(774)
Equity in earnings of investees	(35,518)	(18,640)	(10,963)
Net (gain) loss on issuance of shares by Select Income REIT	(86)	42,145	53
Loss on distribution to common shareholders of The RMR Group Inc. common stock	0	12,368	0
Loss on impairment of Select Income REIT investment	0	203,297	0
Distributions of earnings from Select Income REIT	32,425	21,882	17,046
Change in assets and liabilities:
Restricted cash	492	1,258	(591)
Deferred leasing costs	(10,196)	(4,741)	(3,326)
Rents receivable	1,670	(2,729)	(337)
Other assets	25	515	(419)
Accounts payable and accrued expenses	1,970	1,097	6,400
Due to related persons	634	725	(402)
Net cash provided by operating activities	124,258	115,357	130,725
CASH FLOWS FROM INVESTING ACTIVITIES:
Real estate acquisitions and deposits	(200,331)	0	(56,350)
Real estate improvements	(32,999)	(19,163)	(21,635)
Investment in Select Income REIT	0	(95,821)	(689,969)
Investment in The RMR Group Inc.	0	(7,226)	0
Investment in Affiliates Insurance Company	0	0	(825)
Distributions in excess of earnings from Select Income REIT	17,910	25,148	3,594
Proceeds from sale of properties, net	263	30,460	16,426
Net cash used in investing activities	(215,157)	(66,602)	(748,759)
CASH FLOWS FROM FINANCING ACTIVITIES:
Repayment of mortgage notes payable	(107,933)	(48,908)	(2,221)
Proceeds from issuance of common shares, net	0	0	349,787
Proceeds from issuance of senior notes	310,000	0	347,217
Proceeds from unsecured term loans	0	0	1,050,000
Repayment of unsecured term loans	0	0	(850,000)
Borrowings on unsecured revolving credit facility	399,000	195,000	344,500
Repayments on unsecured revolving credit facility	(356,000)	(78,000)	(501,500)
Payment of debt issuance costs	(10,309)	(21)	(12,765)
Repurchase of common shares	(337)	(172)	0
Distributions to common shareholders	(122,366)	(121,660)	(100,856)
Net cash provided by (used in) financing activities	112,055	(53,761)	624,162
Increase (decrease) in cash and cash equivalents	21,156	(5,006)	6,128
Cash and cash equivalents at beginning of year	8,785	13,791	7,663
Cash and cash equivalents at end of year	29,941	8,785	13,791
Supplemental cash flow information:
Interest paid	41,139	35,500	21,334
Income taxes paid	111	143	126
Non-cash investing activities:
Investment in The RMR Group Inc. paid in common shares	0	13,545	0
Sale of property	3,600	0	0
Mortgage note receivable related to sale of property	(3,600)	0	0
Real estate acquisition funded by the assumption of mortgage debt	0	0	(97,524)
Distribution of The RMR Group Inc. common stock received from Select Income REIT	0	5,244	0
Non-cash financing activities:
Assumption of mortgage debt	0	0	97,524
Distribution to common shareholders of The RMR Group Inc. common stock	$ 0	$ (9,132)	$ 0

Organization

Organization	12 Months Ended
	Dec. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization	Organization Government Properties Income Trust, or the Company, we or us, is a real estate investment trust, or REIT, formed in 2009 under Maryland law. As of December 31, 2016 , excluding one property ( one building) classified as discontinued operations, we owned 73 properties ( 95 buildings), or our Properties, located in 31 states and the District of Columbia containing approximately 11.4 million rentable square feet. As of December 31, 2016 , we also owned 24,918,421 common shares of beneficial interest, par value $0.01 per share, or approximately 27.9% , of the then outstanding common shares of Select Income REIT, or SIR.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2016
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 100% 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 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. For properties qualifying as acquired businesses under Accounting Standards Codification 805, Business Combinations , 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. We amortize capitalized above market lease values (included in acquired in place real estate leases in our consolidated balance sheets) and below market lease values (presented as assumed real estate lease obligations 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 $1,457 , $1,155 , and $868 during the years ended December 31, 2016 , 2015 and 2014 , respectively. We amortize the value of acquired in place leases (included in acquired real estate leases 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 $27,546 , $27,467 , and $26,844 during the years ended December 31, 2016 , 2015 and 2014 , respectively. When a lease is terminated prior to its stated expiration, we write off the unamortized amounts relating to that lease. Capitalized above market lease values were $39,261 and $37,875 as of December 31, 2016 and 2015 , respectively, net of accumulated amortization of $22,753 and $21,469 , respectively. Capitalized below market lease values were $20,603 and $25,553 as of December 31, 2016 and 2015 , respectively, net of accumulated amortization of $9,977 and $12,818 , respectively. The value of acquired in place leases, exclusive of the value of above market and below market acquired in place leases, was $203,368 and $188,471 as of December 31, 2016 and 2015 , respectively, net of accumulated amortization of $95,028 and $86,610 , respectively. As of December 31, 2016 , the weighted average amortization periods for capitalized above market leases, lease origination value and capitalized below market lease values were 4.4 years, 5.0 years and 6.7 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, 2016 are estimated to be $33,578 in 2017 , $28,828 in 2018 , $19,853 in 2019 , $10,478 in 2020 , $7,959 in 2021 and $13,526 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. 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. Equity Method Investments. We account for our investments in Affiliates Insurance Company, or AIC, and SIR using the equity method of accounting. Significant influence is present through common representation on the boards of trustees or directors of us, AIC and SIR and our significant ownership interest in SIR. Our Managing Trustees are also the managing trustees of SIR. Our Managing Trustees are also directors, officers and controlling shareholders (through ABP Trust) of The RMR Group Inc., or RMR Inc. Substantially all of the business of RMR Inc. is conducted by its majority owned subsidiary, The RMR Group LLC, or RMR LLC, which is the manager of us, AIC and SIR. Each of our Trustees is a director of AIC and one of our Independent Trustees is also an independent trustee of SIR. See Notes 7 and 12 for a further discussion of our investments in AIC and SIR. 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. We recorded a $203,297 loss on impairment of our SIR investment in 2015 . See Note 12 for more information on this impairment. 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. Revenue Recognition. We recognize rental income from operating leases that contain fixed contractual rent changes on a straight line basis over the term of the lease agreements. We increased rental income by $2,691 , $3,978 and $4,495 to record revenue on a straight line basis during the years ended December 31, 2016 , 2015 and 2014 , respectively. Rents receivable include $21,686 and $18,995 of straight line rent receivables at December 31, 2016 and 2015 , respectively. Certain of our leases with government tenants provide the tenant the right to terminate its lease if its respective legislature or other funding authority does not appropriate the funding necessary for the government tenant to meet its lease obligations; we have determined the fixed non-cancelable lease term of these leases to be the fully executed term of the lease because we believe the occurrence of termination to be a remote contingency based on both our historical experience and our assessment of the likelihood of lease cancellation on a separate lease basis. Deferred Leasing Costs . Deferred leasing costs include brokerage, legal and other fees associated with our entering leases and we amortize those costs, which are included in depreciation and amortization expense, on a straight line basis over the terms of the respective leases. Deferred leasing costs totaled $28,039 and $20,300 at December 31, 2016 and 2015 , respectively, and accumulated amortization of deferred leasing costs totaled $6,960 and $6,001 at December 31, 2016 and 2015 , respectively. Future amortization of deferred leasing costs to be recognized during the current terms of our existing leases as of December 31, 2016 , are estimated to be $3,598 in 2017 , $3,279 in 2018 , $3,115 in 2019 , $2,521 in 2020 , $2,086 in 2021 and $6,480 thereafter. Available for Sale Securities. As of December 31, 2016 , we owned 1,214,225 common shares of class A common stock of RMR Inc. Our investment in RMR Inc. is classified as an available for sale security. Available for sale securities are recorded at fair value based on their quoted market price at the end of each reporting period. Unrealized gains and losses on available for sale securities are recorded as a component of cumulative other comprehensive income (loss) in shareholders’ equity. As further described in Note 7 , 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 and $1,268 of this liability during the years ended December 31, 2016 and 2015, respectively. These amounts are included in the net business management and property management fee amounts for such periods. As of December 31, 2016, the remaining unamortized amount of this liability was $20,667 . We evaluate our investments in available for sale securities to determine if a decline in the fair value below our carrying value is other than temporary. We consider the severity and the duration of the decline, and our ability and intent to hold the investment until recovery when making this assessment. If a decline in fair value is determined to be other than temporary, an impairment loss equal to the difference between the investment’s carrying value and its fair value is recognized in earnings. 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, 2016 and 2015 , debt issuance costs for our revolving credit facility were $5,234 and $5,234 , respectively, and accumulated amortization of debt issuance costs for our revolving credit facility were $2,617 and $1,385 , respectively. Debt issuance costs, net of accumulated amortization, for our unsecured 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, 2016 and 2015 , debt issuance costs, net of accumulated amortization, for our unsecured term loans, senior unsecured notes, and mortgage notes payable totaled $14,725 and $6,026 , respectively. Future amortization of debt issuance costs to be recognized with respect to our revolving credit facility, unsecured term loans, senior unsecured notes and mortgage notes as of December 31, 2016 are estimated to be $2,892 in 2017 , $2,896 in 2018 , $1,639 in 2019 , $779 in 2020 , $640 in 2021 and $8,496 thereafter. Income Taxes. We have elected to be taxed as a REIT under the United States Internal Revenue Code of 1986, as amended, or the IRC, 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 as a REIT. We are, however, subject to certain state and local taxes. Cumulative Other Comprehensive Income (Loss). Cumulative other comprehensive income (loss) represents the unrealized gain (loss) on the RMR Inc. shares we own and our share of the cumulative comprehensive income (loss) of our equity method investees, SIR and AIC. See Notes 2, 7 and 12 for further information regarding these investments. Reclassifications. Certain reclassifications have been made to the prior years’ financial statements to conform to the current year’s presentation. 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. Per Common Share Amounts. We calculate basic earnings per common share by dividing net income (loss) 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. Segment Reporting. We operate in two business segments: ownership of properties that are primarily leased to government tenants and our equity method investment in SIR.

Weighted Average Common Shares

Weighted Average Common Shares	12 Months Ended
	Dec. 31, 2016
Earnings Per Share, Basic and Diluted [Abstract]
Weighted Average Common Shares	Weighted Average Common Shares The following table provides a reconciliation of the weighted average number of common shares used in the calculation of basic and diluted earnings per share (in thousands): For the Year Ended December 31, 2016 2015 2014 Weighted average common shares for basic earnings per share 71,050 70,700 61,313 Effect of dilutive securities: unvested share awards 21 — 86 Weighted average common shares for diluted earnings per share 71,071 70,700 61,399

Recent Accounting Pronouncement

Recent Accounting Pronouncements	12 Months Ended
	Dec. 31, 2016
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Recent Accounting Pronouncements	Recent Accounting Pronouncements On January 1, 2016, we adopted the Financial Accounting Standards Board, or FASB, Accounting Standards Update, or ASU, No. 2015-02, Consolidation . Among other things, this update changes how an entity determines the primary beneficiary of a variable interest entity. The implementation of this update did not have an impact in our consolidated financial statements. On January 1, 2016, we adopted FASB ASU No. 2015-03, Simplifying the Presentation of Debt Issuance Costs , which requires debt issuance costs to be presented in the balance sheet as a direct deduction from the associated debt liability, and FASB ASU No. 2015-15, Presentation and Subsequent Measurement of Debt Issuance Costs Associated with Line-of-Credit Arrangements —Amendments to SEC Paragraphs Pursuant to Staff Announcement at June 18, 2015 EITF Meeting , which addresses the presentation of debt issuance costs related to line of credit arrangements. The implementation of these updates resulted in the reclassification of certain of our capitalized debt issuance costs as an offset to the associated debt liability in our consolidated balance sheets. The classification of capitalized debt issuance costs related to our revolving credit facility remains unchanged in accordance with ASU No. 2015-15. As of December 31, 2015, debt issuance costs related to our unsecured term loans, senior unsecured notes and mortgage notes payable of $3,510 , $2,172 and $344 , respectively, were reclassified from assets to the associated debt liability in our consolidated balance sheets. On January 1, 2016, we adopted FASB ASU No. 2015-16, Simplifying the Accounting for Measurement-Period Adjustments , which eliminates the requirement for an acquirer in a business combination to account for measurement period adjustments retrospectively. Instead, acquirers must recognize measurement period adjustments during the period in which they determine the amounts, including the effect on earnings of any amounts they would have recorded in previous periods if the accounting had been completed at the acquisition date. The implementation of this update did not have an impact in our consolidated financial statements. On December 31, 2016, we adopted FASB ASU No. 2014-15, Presentation of Financial Statements—Going Concern : Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern . This update requires an entity to evaluate whether there are conditions or events that raise substantial doubt about the entity’s ability to continue as a going concern within one year after the date that the financial statements are issued (or within one year after the financial statements are available to be issued when applicable) and to provide related footnote disclosures in certain circumstances. The implementation of this update did not have an impact in our consolidated financial statements. In 2014, the FASB issued ASU No. 2014-09, Revenue From Contracts With Customers ("ASU 2014-09"), which outlines a comprehensive model for entities to use in accounting for revenue arising from contracts with customers. ASU No. 2014-09 states that “an entity recognizes revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services.” While ASU No. 2014-09 specifically references contracts with customers, it may apply to certain other transactions such as the sale of real estate or equipment. In 2015, the FASB provided for a one-year deferral of the effective date for ASU No. 2014-09, which is now effective for us beginning January 1, 2018. A substantial portion of our revenue consists of rental income from leasing arrangements, which is specifically excluded from ASU 2014-09. We are continuing to evaluate ASU No. 2014-09 (and related clarifying guidance issued by the FASB); however, we do not expect its adoption to have a significant impact on the timing of our revenue recognition in the consolidated financial statements with the exception of profit recognition on real estate sales. We currently have a deferred gain on sale of real estate of $712 that would have been recognized in 2021 or upon repayment of a promissory note we received in connection with the sale but will be recognized in its entirety upon adoption of the standard. In January 2016, the FASB issued ASU No. 2016-01, Recognition and Measurement of Financial Assets and Financial Liabilities , which changes how entities measure certain equity investments and present changes in the fair value of financial liabilities measured under the fair value option that are attributable to their own credit. This update is effective for interim and annual periods beginning after December 15, 2017, with early adoption permitted subject to certain conditions. Currently, changes in fair value of these investments are recorded through other comprehensive income (loss). ASU No. 2016-01 states that these changes will be recorded through earnings. We are continuing to evaluate this guidance, but we expect the implementation of this guidance will affect how changes in the fair value of available for sale securities we hold are presented in our consolidated financial statements. In February 2016, the FASB issued ASU No. 2016-02, Leases , which sets out the principles for the recognition, measurement, presentation and disclosure of leases for both parties to a contract (i.e., lessees and lessors). 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. A lessee is also required to record a right of use asset and a lease liability for all leases with a term of greater than 12 months regardless of their classification. Leases with a term of 12 months or less will be accounted for similar to existing guidance for operating leases today. The new standard requires lessors to account for leases using an approach that is substantially equivalent to existing guidance for sales type leases, direct financing leases and operating leases. ASU No. 2016-02 is effective for reporting periods beginning after December 15, 2018, with early adoption permitted. We are currently assessing the potential impact the adoption of ASU No. 2016-02 will have in our consolidated financial statements. In March 2016, the FASB issued ASU No. 2016-09, Compensation - Stock Compensation , which identifies areas for simplification involving several aspects of accounting for share based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, an option to recognize gross stock compensation expense with actual forfeitures recognized as they occur, as well as certain classifications on the statement of cash flows. ASU No. 2016-09 is effective for reporting periods beginning after December 31, 2016. We do not expect the adoption of ASU No. 2016-09 to have a material impact in our consolidated financial statements. 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 for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. We are currently assessing the potential impact that adoption of ASU No. 2016-13 will have in our consolidated financial statements. In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments , which clarifies how companies present and classify certain cash receipts and cash payments in the statement of cash flows. ASU No. 2016-15 is effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. We are currently assessing the potential impact that adoption of ASU No. 2016-15 will have in our consolidated financial statements. In November 2016, the FASB issued ASU No. 2016-18, Restricted Cash , which clarifies how companies should present restricted cash and restricted cash equivalents. Companies will show the changes in the total of cash, cash equivalents, restricted cash and restricted cash equivalents in the statement of cash flows. The new standard requires a reconciliation of the totals in the statement of cash flows to the related captions in the balance sheet. ASU No. 2016-18 is effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. We are currently assessing the potential impact that adoption of ASU No. 2016-18 will have in our consolidated financial statements. In January 2017, the FASB issued ASU No. 2017-01, Clarifying the Definition of a Business , which provides additional guidance on evaluating whether transactions should be accounted for as an acquisition (or disposal) of assets or of a business. The update defines three requirements for a set of assets and activities (collectively referred to as a “set”) to be considered a business: inputs, processes and outputs. ASU No. 2017-01 is effective for annual periods beginning after December 15, 2017, including interim periods within those fiscal years. This update will be applied prospectively to any transactions occurring within the period of adoption. We are currently assessing the impact of the update; however, subsequent to adoption we believe certain property acquisitions which under previous guidance would have been accounted for as business combinations will be accounted for as acquisitions of assets. In an acquisition of assets, certain acquisition costs are capitalized as opposed to expensed under business combination guidance.

Real Estate Properties

Real Estate Properties	12 Months Ended
	Dec. 31, 2016
Real Estate [Abstract]
Real Estate Properties	Real Estate Properties As of December 31, 2016 , we owned 73 properties ( 95 buildings), with an undepreciated carrying value of $1,888,760 , excluding one property ( one building) classified as discontinued operations with an undepreciated carrying value of $12,260 . We generally lease space at our properties on a gross lease or modified gross lease basis pursuant to fixed term contracts expiring between 2017 and 2032. 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, 2016 , we entered into 61 leases for 1,613,041 rentable square feet, including a 25,579 square foot expansion to be constructed at an existing property, for a weighted (by rentable square feet) average lease term of 8.6 years and we made commitments for approximately $38,489 of leasing related costs. As of December 31, 2016 , we have estimated unspent leasing related obligations of $26,459 plus we have committed to redevelop and expand an existing property at an estimated cost to complete of approximately $15,355 . During the year ended December 31, 2016 , we capitalized $52 of interest expense related to the redevelopment and expansion of the existing property referenced above. Our future minimum lease payments related to our properties, excluding one property ( one building) classified as discontinued operations, and estimated real estate tax and other expense reimbursements scheduled to be received during the current terms of the existing leases as of December 31, 2016 are as follows: 2017 $ 242,867 2018 219,676 2019 190,106 2020 140,014 2021 118,815 Thereafter 364,419 $ 1,275,897 Certain of our government tenants have the right to terminate their leases before the lease term expires. As of December 31, 2016 , excluding one property ( one building) classified as discontinued operations, government tenants who currently represent approximately 6.6% of our total future minimum lease payments have currently exercisable rights to terminate their leases before the stated terms of their leases expire. In 2017 , 2018 , 2019 , 2020 , 2021 , 2022 , 2023 , 2026 and 2027 , early termination rights become exercisable by other government tenants who currently represent an additional approximately 1.8% , 1.8% , 7.3% , 12.8% , 1.3% , 4.6% , 2.8% , 3.7% , and 2.2% of our total future minimum lease payments, respectively. In addition, as of December 31, 2016 , 15 of our government tenants have the currently exercisable right to terminate their leases if the respective legislature or other funding authority does not appropriate the funding necessary for the government tenant to meet its obligation. These 15 tenants represent approximately 18.8% of our total future minimum lease payments as of December 31, 2016 . Acquisition Activities During the year ended December 31, 2016 , we acquired three properties ( five buildings) with a combined 830,185 rentable square feet and a land parcel adjacent to one of our existing properties for an aggregate purchase price of $199,031 , excluding acquisition costs. Our allocation of the purchase price of these acquisitions based on the estimated fair value of the acquired assets and assumed liabilities is presented in the table below. Number of Buildings Other Acquired Acquisition Properties/ Square Purchase and Assumed Acquired Lease Date Location Type Buildings Feet Price (1) Land Improvements Assets Leases Obligations 1/29/2016 Sacramento, CA (2) Office 1 / 1 337,811 $ 79,235 $ 4,688 $ 61,722 $ 2,167 $ 11,245 $ (587 ) 7/6/2016 Atlanta, GA (3) Land — — 1,670 1,670 — — — — 12/20/2016 Rancho Cordova, CA (2)(4) Office 1 / 1 82,896 13,943 1,465 8,537 — 3,941 — 12/22/2016 Chantilly, VA (2)(4) Office 1 / 3 409,478 104,183 6,974 74,116 — 23,093 — 3 / 5 830,185 $ 199,031 $ 14,797 $ 144,375 $ 2,167 $ 38,279 $ (587 ) (1) Excludes acquisition costs. (2) Accounted for as a business combination. (3) On July 6, 2016, we acquired a land parcel adjacent to on our existing properties for $1,623 . We accounted for this transaction as an asset acquisition and capitalized acquisition related costs of $47 . (4) The allocation of the purchase price is based on preliminary estimates and may change upon the completion of (i) third party valuations and (ii) our analysis of acquired in place lease and land and building valuations. In August 2016, we entered an agreement to acquire transferable development rights that would allow us to expand a property we own in Washington, D.C. for a purchase price of $2,030 , excluding acquisition costs. In January 2017, we acquired an office property ( one building) located in Manassas, VA with 69,374 rentable square feet for a purchase price of $13,200 , excluding acquisition related costs. Our pending acquisitions are subject to conditions; accordingly, we cannot be sure that we will complete these acquisitions or that these acquisitions will not be delayed or the terms of these acquisitions will not change. Disposition Activities – Continuing Operations In July 2016, we sold an office property ( one 1 building ) in Savannah, GA with 35,228 rentable square feet that had a net book value of $2,986 for $4,000 , excluding closing costs. In connection with this sale, 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. This sales transaction did not qualify for full gain recognition under GAAP and is being accounted for under the installment method. Accordingly, we recognized a gain on sale of real estate of $79 during the year ended December 31, 2016 and recorded a deferred gain of $712 , which we currently expect to recognize when the mortgage note is repaid. The mortgage note receivable of $3,600 , net of the $712 deferred gain, is included in other assets in our consolidated balance sheet at December 31, 2016 . We classified this property as held for sale as of June 30, 2016. The results of operations for this property were included in continuing operations in our consolidated financial statements up to the date of sale. Summarized balance sheet information for the property as of December 31, 2015 is as follows: December 31, 2015 Real estate properties, net $ 3,071 Rents receivable 1 Other assets 26 Assets of property held for sale $ 3,098 Other liabilities $ 43 Liabilities of property held for sale $ 43 Disposition Activities – Discontinued Operations In March 2016, we entered an agreement to sell an office property ( one building) in Falls Church, VA with 164,746 rentable square feet and a net book value of $12,282 at December 31, 2016 . The contract sales price is $13,148 , excluding closing costs. This sale is subject to conditions, and we cannot be sure that the sale of this property will occur, that the sale will not be delayed or that its terms will not change. Results of operations for two properties ( two buildings) we sold in 2014 and the Falls Church, VA property ( one building) disclosed above, 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. Summarized balance sheet and income statement information for the properties classified as discontinued operations is as follows: Balance Sheets December 31, December 31, 2016 2015 Real estate properties, net $ 12,260 $ 12,260 Other assets 281 208 Assets of discontinued operations $ 12,541 $ 12,468 Other liabilities $ 45 $ 54 Liabilities of discontinued operations $ 45 $ 54 Statements of Operations Year Ended December 31, 2016 2015 2014 Rental income $ 68 $ 114 $ 1,673 Real estate taxes (97 ) (92 ) (427 ) Utility expenses (146 ) (161 ) (226 ) Other operating expenses (300 ) (272 ) (459 ) General and administrative (114 ) (114 ) (181 ) Increase in carrying value of asset held for sale — — 2,344 Net gain on sale of properties — — 774 Income (loss) from discontinued operations $ (589 ) $ (525 ) $ 3,498

Business and Property Managemen

Business and Property Management Agreements with RMR LLC	12 Months Ended
	Dec. 31, 2016
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 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. See Note 7 for further information regarding our relationship, agreements and transactions with RMR LLC. Fees. 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: • 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 applicable 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, we do not include our ownership of SIR common shares as part of our real estate investments for purposes of calculating our base management fee due to RMR LLC since SIR pays separate management fees to RMR LLC. • Incentive Fee. The incentive 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 measurement period, and ▪ the amount (expressed as a percentage) by which the total returns per share realized by our common shareholders (i.e., share price appreciation plus dividends) exceeds the total shareholder return of the SNL U.S. REIT Equity Index (in each case subject to certain adjustments) for the relevant measurement period. ◦ The measurement periods are generally three year periods ending with the year for which the incentive fee is being calculated, with shorter periods applicable in the case of the calculation of the incentive fee for 2015 ( two years ) and 2014 ( one year ). ◦ The benchmark return per share is adjusted if our total return per share exceeds 12% per year in any measurement period and, generally, no incentive management fee is payable by us unless our total return per share during the measurement period is positive. ◦ The incentive management fee is subject to a cap equal to the value of 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. ◦ If our financial statements 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, for one or more periods in respect of which RMR LLC received an incentive management fee, the incentive management fee payable with respect to periods for which there has been a restatement shall be recalculated by, and approved by a majority vote of, our Independent Trustees, and RMR LLC may be required to pay us an amount equal to the value in excess of that which RMR LLC would have received based upon the incentive management fee as recalculated, either in cash or our common shares. • 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 business management agreement with RMR LLC, we recognized net business management fees of $10,222 , $9,934 and $10,226 for the years ended December 31, 2016, 2015 and 2014, respectively. The net business management fees we recognized are included in general and administrative expenses for these periods. The net business management fees we recognized for the years ended December 31, 2016 and 2015 reflect a reduction of $603 and $372 , respectively, for the amortization of the liability we recorded in connection with the Up-C Transaction, as further described in Note 2 under “ Available for Sale Securities. ” In accordance with the then applicable terms of our business management agreement, we issued 19,339 of our common shares to RMR LLC for the period from January 1, 2015 to May 31, 2015, and we issued 42,442 of our common shares to RMR LLC for the year ended December 31, 2014, in each case as payment for a part of the base business management fee we recognized. Beginning June 1, 2015, all management fees under our business management agreement are paid in cash. No incentive fee was payable to RMR LLC under our business management agreement for the years ended December 31, 2016, 2015 or 2014. Pursuant to our property management agreement with RMR LLC, we recognized aggregate net property management and construction supervision fees of $8,949 , $7,977 and $8,203 for the years ended December 31, 2016, 2015 and 2014, respectively. These amounts are included in other operating expenses or have been capitalized, as appropriate, in our consolidated financial statements. Expense Reimbursement . We are generally responsible for all of our operating expenses, including certain expenses incurred by RMR LLC on our behalf. 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 $12,276 , $9,641 and $7,982 for property management related expenses for the years ended December 31, 2016, 2015 and 2014, respectively. These amounts are included in other operating expenses in our consolidated statements of comprehensive income (loss) for these periods. 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 centralized accounting personnel and our share of RMR LLC’s costs for providing our internal audit function. Our Audit Committee appoints our Director of Internal Audit and our Compensation Committee approves the costs of our internal audit function. The amounts recognized as expense for internal audit costs were $235 , $252 and $286 for the years ended December 31, 2016, 2015 and 2014, respectively. These amounts are included in general and administrative expenses in our consolidated statements of comprehensive income (loss) for these periods. Term . Our management agreements with RMR LLC have terms that end on December 31, 2036, 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: (1) at any time on 60 days’ written notice for convenience, (2) immediately on written notice for cause, as defined therein, (3) on 60 days’ written notice given within 60 days after the end of an applicable calendar year for a performance reason, as defined therein, and (4) 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, 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 provides management services for the purpose of obtaining more favorable terms from such vendors and suppliers.

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2016
Related Party Transactions [Abstract]
Related Party Transactions	Related Person Transactions We have relationships and historical and continuing transactions with RMR LLC, RMR Inc. and others related to them. RMR LLC is a subsidiary of RMR Inc. One of our Managing Trustees, Adam Portnoy, is a managing director, president, chief executive officer and controlling shareholder (through ABP Trust) of RMR Inc. and an officer of RMR LLC. Our other Managing Trustee, Barry Portnoy, is a managing director, officer and controlling shareholder (through ABP Trust) of RMR Inc. and an officer of RMR LLC. ABP Trust is owned by Adam Portnoy and Barry Portnoy. Adam Portnoy and Barry Portnoy also own class A membership units of RMR LLC (through ABP Trust). Each of our executive officers is also an officer of RMR LLC. Our Independent Trustees also serve as independent directors or independent trustees of other companies to which RMR LLC or its affiliates provide management services. Barry Portnoy serves as a managing director or managing trustee of all of the public companies to which RMR LLC or its affiliates provide management services and Adam Portnoy serves as a managing trustee of a majority of those 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 affiliates provide management services. See Note 6 for further information regarding our relationship with RMR LLC. Our Manager, 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. See Note 6 for further 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 $366 , $341 and $61 for the years ended December 31, 2016, 2015 and 2014, 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 . We have historically granted share awards to certain RMR LLC employees under our equity compensation plan. During the years ended December 31, 2016, 2015 and 2014, we awarded annual share grants of 53,400 , 53,100 and 51,150 of our common shares, respectively, to our officers and to other employees of RMR LLC, valued at $1,183 , $841 and $1,191 , respectively, based upon the closing price of our common shares on the applicable stock exchange on which our common shares were listed on the dates of grant. One fifth of these awards vested on the applicable grant dates and one fifth vests on each of the next four anniversaries of the grant dates. These awards to RMR LLC employees are in addition to the share awards granted to Adam Portnoy and Barry Portnoy, our Managing Trustees, and the fees we paid to RMR LLC. During 2016 and 2015, we purchased some of our common shares from our officers and certain other employees of RMR LLC in satisfaction of tax withholding and payment obligations in connection with the vesting of awards of our common shares. See Note 11 for further information regarding these purchases. Acquisition of Interest in RMR LLC, Our Manager . On June 5, 2015, we and three other REITs to which RMR LLC provides management services - Hospitality Properties Trust, SIR and Senior Housing Properties Trust, or collectively, the Other REITs - participated in a transaction, or the Up-C Transaction, by which we and the Other REITs each acquired shares of class A common stock of RMR Inc. The Up-C Transaction was completed pursuant to a transaction agreement by and among us, RMR LLC, its then sole member, ABP Trust, and RMR Inc. and similar transaction agreements that each Other REIT entered into with RMR LLC, ABP Trust and RMR Inc. As part of the Up-C Transaction and concurrently with entering into the transaction agreements, on June 5, 2015, among other things: • We contributed 700,000 of our common shares and $3,917 in cash to RMR Inc. and RMR Inc. issued 1,541,201 shares of its class A common stock to us. • We agreed to distribute approximately half of the shares of class A common stock of RMR Inc. issued to us in the Up-C Transaction to our shareholders as a special distribution. • We entered into amended and restated business and property management agreements with RMR LLC which, among other things, amended the term, termination and termination fee provisions of those agreements. See Note 6 for further information regarding our management agreements with RMR LLC. • We entered into a registration rights agreement with RMR Inc. covering the shares of class A common stock of RMR Inc. issued to us in the Up-C Transaction, pursuant to which we received demand and piggyback registration rights, subject to certain limitations. • We entered into a lock up and registration rights agreement with ABP Trust, Adam Portnoy and Barry Portnoy pursuant to which they agreed not to transfer the 700,000 of our common shares ABP Trust received in the Up-C Transaction for a 10 year period ending on June 5, 2025 and we granted them certain registration rights, subject, in each case, to certain exceptions. Each Other REIT participated in the Up-C Transaction in a similar manner. After giving effect to the Up-C Transaction, RMR LLC became a subsidiary of RMR Inc. and RMR Inc. became the managing member of RMR LLC. Pursuant to the transaction agreements for the Up-C Transaction, on December 14, 2015, we distributed 768,032 shares of class A common stock of RMR Inc. to our shareholders as a special distribution, which represented approximately half of the shares of class A common stock of RMR Inc. issued to us in the Up-C Transaction; each Other REIT also distributed approximately half of the shares of class A common stock of RMR Inc. issued to it in the Up-C Transaction to its respective shareholders. As a shareholder of SIR we received 441,056 class A common shares of RMR Inc. included in such shares that SIR distributed to its shareholders. RMR Inc. facilitated these distributions by filing a registration statement with the SEC to register the shares of class A common stock of RMR Inc. being distributed and by listing those shares on The NASDAQ Stock Market LLC, or Nasdaq. In connection with this distribution, we recognized a non-cash loss of $12,368 in the fourth quarter of 2015 as a result of the closing price of the class A common stock of RMR Inc. being lower than our carrying amount per share on the distribution date. See Notes 2 and 10 for information regarding the fair value of our investment in RMR Inc. as of December 31, 2016. Through their ownership of class A common stock of RMR Inc., class B-1 common stock of RMR Inc., class B-2 common stock of RMR Inc. and class A membership units of RMR LLC, as of December 31, 2016, Adam Portnoy and Barry Portnoy in aggregate hold, directly and indirectly, a 51.9% economic interest in RMR LLC and control 91.5% of the voting power of outstanding capital stock of RMR Inc. We currently hold 1,214,225 shares of class A common stock of RMR Inc., including 441,056 shares of class A common stock of RMR Inc. that SIR distributed to us as a result of our ownership of SIR common shares. EQC. We were formerly a 100% owned subsidiary of Equity Commonwealth, or EQC. In 2009, we completed our initial public offering and ceased to be a majority owned subsidiary of EQC. One of our Managing Trustees, Adam Portnoy, was the president of EQC until May 23, 2014 and a managing trustee of EQC until March 25, 2014. Our other Managing Trustee, Barry Portnoy, was a managing trustee of EQC until March 25, 2014. RMR LLC generally provided business and property management services to EQC until September 30, 2014, when the applicable management agreements were terminated, except that RMR LLC provided management services to EQC in respect of EQC’s Australian assets and certain transition services to EQC until October 31, 2015. On July 8, 2014, we and RMR LLC entered into a stock purchase agreement, or the purchase agreement, with EQC, pursuant to which, on July 9, 2014, we acquired from EQC 21,500,000 SIR common shares, and RMR LLC acquired from EQC 500,000 SIR common shares. Our cash purchase price was equal to $677,500 , or $31.51 per share, plus $11,300 , or $0.53 per share, of accrued dividends as defined in the purchase agreement, for a total of $688,800 , before acquisition related costs. RMR LLC purchased its 500,000 SIR common shares on the same terms, including for the same per share amounts that we paid. In addition, we and RMR LLC agreed, among other things, to indemnify EQC for certain claims related to the acquisition. In connection with the indemnity, we and RMR LLC entered into an allocation agreement with regard to our respective liabilities in the event of a claim for indemnification. On July 23, 2014, we and EQC agreed to terminate the provisions of a transaction agreement that we entered into in 2009 with EQC in connection with our initial public offering. The agreement had placed restrictions on both our and EQC’s investments in real property and provided certain rights of first refusal with respect to properties which we or EQC determined to divest. Since March 25, 2014, we have not considered EQC to be a related party. SIR. We are SIR’s largest shareholder, owning approximately 27.9% of the outstanding SIR common shares as of December 31, 2016. RMR LLC provides management services to both us and SIR. Our Managing Trustees, Adam Portnoy and Barry Portnoy, are also managing trustees of SIR. One of our Independent Trustees also serves as an independent trustee of SIR and our President and Chief Operating Officer also serves as the president and chief operating officer of SIR. On February 28, 2015, we entered into a share purchase agreement, or the SIR Purchase Agreement, with Lakewood Capital Partners, LP, or Lakewood, and certain other related persons, or the Lakewood Parties, and, for the purpose of specified sections, SIR, pursuant to which, on March 4, 2015, we acquired from Lakewood 3,418,421 SIR common shares, representing approximately 3.9% of the then outstanding SIR common shares, for $95,203 . On February 28, 2015, our Managing Trustees, Adam Portnoy and Barry Portnoy, entered into similar separate share purchase agreements with the Lakewood Parties pursuant to which, on March 4, 2015, Adam Portnoy and Barry Portnoy acquired 87,606 and 107,606 SIR common shares, respectively, from Lakewood and, on March 5, 2015, Adam Portnoy and Barry Portnoy each acquired 2,429 SIR common shares from William H. Lenehan, one of the Lakewood Parties. AIC. We, ABP Trust, SIR and four other companies to which RMR LLC provides management services currently own AIC, an Indiana insurance company, in equal amounts and are parties to an amended and restated shareholders agreement regarding AIC. All of our Trustees and all of the trustees and directors of the other AIC shareholders currently serve on the board of directors of AIC. RMR LLC provides management and administrative services to AIC pursuant to a management and administrative services agreement with AIC. Pursuant to this agreement, AIC pays RMR LLC a service fee equal to 3.0% of the total annual earned premiums payable under then active policies issued or underwritten by AIC or by a vendor or an agent of AIC on its behalf or in furtherance of AIC’s business. We and the other AIC shareholders participate in a combined property insurance program arranged and reinsured in part by AIC. We paid aggregate annual premiums, including taxes and fees, of $1,032 , $1,277 and $526 in connection with this insurance program for the policy years ending June 30, 2017, 2016 and 2015, respectively, which amount for the current policy year ending June 30, 2017 may be adjusted from time to time as we acquire and dispose of properties that are included in this insurance program. As of December 31, 2016, 2015 and 2014, our investment in AIC had a carrying value of $7,235 , $6,946 and $6,946 , respectively. These amounts are included in other assets in our consolidated balance sheets. We recognized income of $137 , $20 and $87 related to our investment in AIC for the years ended December 31, 2016, 2015 and 2014, respectively. Our other comprehensive income (loss) includes our proportionate part of unrealized gains (losses) on securities which are owned by AIC of $152 , ($20) and $2 related to our investment in AIC for the years ended December 31, 2016, 2015 and 2014, respectively. Directors’ and Officers’ Liability Insurance. We, RMR Inc., RMR LLC and certain companies to which RMR LLC provides management services, including SIR, participate in a combined directors’ and officers’ liability insurance policy. The combined policy expires in September 2018. We paid aggregate premiums of $106 , $316 and $529 in 2016, 2015 and 2014, respectively, for these policies.

Concentration

Concentration	12 Months Ended
	Dec. 31, 2016
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. The U.S. Government, 13 state governments, and three other government tenants combined were responsible for approximately 87.9% , 92.8% and 93.0% of our annualized rental income, excluding properties classified as discontinued operations, as of December 31, 2016 , 2015 and 2014 , respectively. The U.S. Government is our largest tenant by annualized rental income and was responsible for approximately 60.6% , 67.0% and 69.0% of our annualized rental income, excluding properties classified as discontinued operations, as of December 31, 2016 , 2015 and 2014 , respectively. Geographic Concentration At December 31, 2016 , our 73 properties ( 95 buildings), excluding one property ( one building) classified as discontinued operations, were located in 31 states and the District of Columbia. Properties located in California, Virginia, the District of Columbia, Georgia, New York, Maryland and Massachusetts were responsible for approximately 14.4% , 14.3% , 9.7% , 8.7% , 7.7% , 7.2% and 5.0% of our annualized rental income as of December 31, 2016 , respectively.

Indebtedness

Indebtedness	12 Months Ended
	Dec. 31, 2016
Debt Disclosure [Abstract]
Indebtedness	Indebtedness Our principal debt obligations at December 31, 2016 were: (1) $160,000 of outstanding borrowings under our $750,000 unsecured revolving credit facility; (2) $550,000 aggregate outstanding principal amount of term loans; (3) an aggregate outstanding principal amount of $660,000 of public issuances of senior unsecured notes; and (4) $27,508 aggregate principal amount of mortgage notes. Our $750,000 revolving credit facility, our $300,000 term loan and our $250,000 term loan are governed by a credit agreement with a syndicate of institutional lenders that includes a number of features common to all of these credit arrangements. This credit agreement also includes a feature under which the maximum aggregate borrowing availability may be increased to up to $2,500,000 on a combined basis 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, 2019 and, subject to the payment of an extension fee and meeting other conditions, we have an option to extend the stated maturity date of our revolving credit facility by one year to January 31, 2020. 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 125 basis points per annum at December 31, 2016 on borrowings 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, 2016 . Both the interest rate premium and the facility fee are subject to adjustment based upon changes to our credit ratings. As of December 31, 2016 , the annual interest rate payable on borrowings under revolving credit facility was 2.0% . The weighted average annual interest rate for borrowings under our revolving credit facility was 1.7% , 1.5% and 1.7% , respectively, for the years ended December 31, 2016 , 2015 and 2014 . As of December 31, 2016 and February 21, 2017 , we had $160,000 and $170,000 outstanding under our revolving credit facility, respectively. Our $300,000 unsecured term loan, which matures on March 31, 2020, is prepayable without penalty at any time. We are required to pay interest at a rate of LIBOR plus a premium, which was 140 basis points per annum at December 31, 2016 on the amount outstanding under our $300,000 term loan. The interest rate premium is subject to adjustment based upon changes to our credit ratings. As of December 31, 2016 , the annual interest rate for the amount outstanding under our $300,000 term loan was 2.2% . The weighted average annual interest rate under our $300,000 term loan was 1.9% , 1.6% and 1.9% , respectively, for the years ended December 31, 2016 , 2015 and for the period from November 21, 2014, the date we entered into the credit agreement, to December 31, 2014 . Our $250,000 unsecured term loan, which matures on March 31, 2022, is prepayable without penalty at any time. We are required to pay interest at a rate of LIBOR plus a premium, which was 180 basis points per annum as of December 31, 2016 on the amount outstanding under our $250,000 term loan. The interest rate premium is subject to adjustment based upon changes to our credit ratings. As of December 31, 2016 , the annual interest rate for the amount outstanding under our $250,000 term loan was 2.6% . The weighted average annual interest rate under our $250,000 term loan was 2.3% , 2.0% and 2.3% , respectively, for the years ended December 31, 2016 , 2015 and for the period from November 21, 2014, the date we borrowed our $250,000 term loan, to December 31, 2014 . In May 2016, we issued $300,000 of 5.875% senior unsecured notes due 2046 in an underwritten public offering. In June 2016, the underwriters exercised an option to purchase an additional $10,000 of these notes. The net proceeds from this offering of $299,691 , after offering expenses, were used to repay all amounts then outstanding under our revolving credit facility and for general business purposes. These notes require quarterly payments of interest only through maturity and may be repaid at par (plus accrued and unpaid interest) on or after May 26, 2021. Our $350,000 of 3.75% senior unsecured notes due 2019 require semi-annual payments of interest only through maturity and may be repaid at par (plus accrued and unpaid interest) on or after July 15, 2019 or before that date together with a make whole premium. Both issuances of our senior notes are governed by an indenture and an applicable supplement. Our credit agreement and senior unsecured notes indenture and its 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 manager and property manager. Our senior unsecured notes indenture and its supplements and our credit agreement also contain a number of covenants, including covenants that restrict our ability to incur debts, require us to maintain certain financial ratios 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 senior unsecured notes indenture and its supplements and our credit agreement at December 31, 2016 . In February 2016, we repaid, at par, a $23,473 mortgage note requiring annual interest of 6.21% which was secured by one office property ( one building) located in Landover, MD. This mortgage note was scheduled to mature in August 2016. We recorded a loss on extinguishment of debt of $21 for the year ended December 31, 2016 , which represented unamortized debt issuance costs related to this note. In March 2016, we repaid, at par, an $83,000 mortgage note requiring annual interest of 5.55% which was secured by one office property ( two buildings) located in Reston, VA. This mortgage note was scheduled to mature in April 2016. We recorded a gain on extinguishment of debt of $125 for the year ended December 31, 2016 , which represented the net unamortized debt premium and debt issuance costs related to this note. At December 31, 2016 , three of our properties ( three buildings) with an aggregate net book value of $52,383 are encumbered by three mortgages for an aggregate principal amount of $27,508 . Our mortgage notes are non-recourse, subject to certain limited exceptions and do not contain any material financial covenants. None of our 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 debt as of December 31, 2016 are as follows: Year Principal payment 2017 $ 1,549 2018 1,671 2019 519,439 2020 301,619 2021 13,230 Thereafter 560,000 $ 1,397,508 (1) (1) Total debt outstanding as of December 31, 2016 , net of unamortized premiums, discounts and certain issuance costs totaling $15,656 was $1,381,852 .

Fair Value of Assets and Liabil

Fair Value of Assets and Liabilities	12 Months Ended
	Dec. 31, 2016
Fair Value Disclosures [Abstract]
Fair Value of Assets and Liabilities	Fair Value of Assets and Liabilities The table below presents certain of our assets measured at fair value at December 31, 2016 , 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 Significant Estimated Active Markets for Significant Other Unobservable Fair Identical Assets Observable Inputs Inputs Description Value (Level 1) (Level 2) (Level 3) Recurring Fair Value Measurement Assets: Investment in RMR Inc. (1) $ 47,962 $ 47,962 $ — $ — Non-Recurring Fair Value Measurement Assets: Property held for sale and classified as discontinued operations (2) $ 12,260 $ — $ — $ 12,260 (1) Our 1,214,225 shares of class A common stock of RMR Inc., which are included in other assets in our consolidated balance sheets, are reported at fair value which is based on quoted market prices (Level 1 inputs). Our historical cost basis for these shares is $26,888 as of December 31, 2016 . The unrealized gain of $21,074 for these shares as of December 31, 2016 is included in cumulative other comprehensive income (loss) in our consolidated balance sheets. (2) We estimated the fair value of this property at December 31, 2016 based upon broker estimates of value less estimated sale costs (Level 3 inputs as defined in the fair value hierarchy under GAAP). In addition to the assets described in the table above, our financial instruments include cash and cash equivalents, restricted cash, rents receivable, mortgage note receivable, accounts payable, a revolving credit facility, term loans, senior unsecured notes, mortgage notes payable, amounts due to related persons, other accrued expenses and security deposits. At December 31, 2016 and December 31, 2015 , the fair values of our financial instruments approximated their carrying values in our consolidated financial statements due to their short term nature or variable interest rates, except as follows: As of December 31, 2016 As of December 31, 2015 Carrying Amount (1) Fair Value Carrying Amount (1) Fair Value Senior unsecured notes, 3.75% interest rate, due in 2019 $ 346,952 $ 354,078 $ 345,809 $ 351,692 Senior unsecured notes, 5.875% interest rate, due in 2046 299,892 292,268 — — Mortgage note payable, 6.21% interest rate, due in 2016 (2) (3) — — 23,476 24,038 Mortgage note payable, 5.55% interest rate, due in 2016 (2) (4) — — 83,375 83,457 Mortgage note payable, 5.88% interest rate, due in 2021 (2) 13,841 14,492 14,045 14,678 Mortgage note payable, 7.00% interest rate, due in 2019 (2) 8,778 9,188 9,145 9,645 Mortgage note payable, 8.15% interest rate, due in 2021 (2) 5,218 5,575 6,258 6,711 $ 674,681 $ 675,601 $ 482,108 $ 490,221 (1) Carrying amount includes certain unamortized debt issuance costs and unamortized premiums and discounts. (2) We assumed these mortgages in connection with our acquisitions of the encumbered properties. The stated interest rates for these mortgage debts are the contractually stated rates. We recorded the assumed mortgages at estimated fair value on the date of acquisition and we are amortizing the fair value premiums, if any, to interest expense over the respective terms of the mortgages to reduce interest expense to the estimated market interest rates as of the date of acquisition. (3) This mortgage note was repaid, at par, in February 2016. (4) This mortgage note was repaid, at par, in March 2016. We estimated the fair value of our senior unsecured notes due in 2019 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 in 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 by using discounted cash flow analyses and currently prevailing market terms 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, 2016
Equity [Abstract]
Shareholders' Equity	Note 11 . Shareholders’ Equity Common Share Awards We have common shares available for issuance under the terms of our 2009 Incentive Share Award Plan, or the 2009 Plan. As described in Note 7 , we awarded common shares to our officers and certain other employees of RMR LLC in 2014 , 2015 and 2016 . We also awarded each of our Trustees 2,500 common shares in 2016 with an aggregate market value of $244 ( $49 per Trustee), 2,500 common shares in 2015 with an aggregate market value of $247 ( $49 per Trustee) and 2,500 common shares in 2014 with an aggregate market value of $318 ( $64 per Trustee) as part of their annual compensation. The values of the share grants were based upon the closing price of our common shares on Nasdaq or the New York Stock Exchange, or the NYSE, as applicable, on the date of grant. The common shares awarded to our Trustees vested immediately. The common shares awarded to our officers and certain other employees of RMR LLC vest in five equal annual installments beginning on the date of grant. A summary of shares granted and vested under the terms of the 2009 Plan for the years ended December 31, 2016 , 2015 and 2014 , is as follows: 2016 2015 2014 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 shares, beginning of year 96,725 $20.11 90,338 $23.40 85,451 $23.71 Shares granted 65,900 21.66 65,600 16.59 63,650 23.70 Shared forfeited or repurchased — — (1,020 ) 23.41 — — Shares vested (63,655 ) 20.97 (58,193 ) 21.20 (58,763 ) 24.17 Unvested shares, end of year 98,970 $20.59 96,725 $20.11 90,338 $23.40 The 98,970 unvested shares as of December 31, 2016 are scheduled to vest as follows: 37,880 shares in 2017, 29,810 shares in 2018, 20,600 shares in 2019 and 10,680 shares in 2020. These unvested shares are re-measured at fair value on a recurring basis using quoted market prices of the underlying shares. As of December 31, 2016 , the estimated future compensation expense for the unvested shares was $1,887 based on the closing share price of our common shares on Nasdaq on December 31, 2016 of $19.07 . The weighted average period over which the compensation expense will be recorded is approximately 21 months. During the years ended December 31, 2016 , 2015 and 2014 , we recorded $ 1,371 , $932 and $1,165 , respectively, of compensation expense related to the 2009 Plan. At December 31, 2016 , 1,554,105 of our common shares remained available for issuance under the 2009 Plan. Distributions Cash distributions per share paid by us to our common shareholders for each of the years ended December 31, 2016 , 2015 and 2014 were $1.72 . As described in Note 7 , on December 14, 2015, we distributed 768,032 , or 0.0108 of a share for each of our common shares, of RMR Inc. shares of class A common stock we owed to our common shareholders as a special distribution. This distribution resulted in a taxable in-kind distribution of $0.1284 for each of our common shares. The characterization of our distributions paid in 2016 was 62.74% ordinary income, 36.21% return of capital and 1.05% qualified dividend. The characterization of our distributions paid in 2015 was 47.44% ordinary income, 37.12% return of capital, 12.90% capital gain, 1.61% IRC Section 1250 gain and 0.93% qualified dividend. The characterization of our distributions paid in 2014 was 55.12% ordinary income, 41.94% return of capital, 2.94% IRC Section 1250 gain. On January 13, 2017, we declared a dividend payable to common shareholders of record on January 23, 2017 in the amount of $0.43 per share, or $30,607 . We expect to pay this distribution on or about February 23, 2017 using cash on hand and borrowings under our revolving credit facility. Share Repurchases In September 2016, we purchased an aggregate of 14,302 of our common shares valued at an average price per common share of $23.54 per common share, based on the closing price of our common shares on Nasdaq on the dates of repurchase, from our officers and certain other employees of RMR LLC in satisfaction of tax withholding and payment obligations in connection with the vesting of awards of our common shares. In September 2015, we purchased an aggregate of 10,721 of our common shares valued at $16.12 per common share, the closing price of our common shares on the NYSE on that day, from our officers and certain other employees of RMR LLC in satisfaction of tax withholding and payment obligations in connection with the vesting of awards of our common shares. Cumulative Other Comprehensive Income (Loss Cumulative other comprehensive income (loss) represents the unrealized gain (loss) on the RMR Inc. shares we own and our share of the comprehensive income (loss) of our equity method investees, SIR and AIC. The following table presents a roll forward of amounts recognized in cumulative other comprehensive income (loss) by component for the years ended December 31, 2016 , 2015 and 2014 : Unrealized Gain (Loss) on Investment in Available for Sale Securities Equity in Unrealized Gains (Losses) of Investees Total Balance at December 31, 2013 $ — $ 49 $ 49 Other comprehensive loss before reclassifications — 37 37 Amounts reclassified from cumulative other comprehensive loss to net income (1) — (49 ) (49 ) Net current period other comprehensive loss — (12 ) (12 ) Balance at December 31, 2014 — 37 37 Other comprehensive loss before reclassifications (9,391 ) (5,592 ) (14,983 ) Amounts reclassified from cumulative other comprehensive loss to net income (1) — 79 79 Net current period other comprehensive loss (9,391 ) (5,513 ) (14,904 ) Balance at December 31, 2015 (9,391 ) (5,476 ) (14,867 ) Other comprehensive income before reclassifications 30,465 11,254 41,719 Amounts reclassified from cumulative other comprehensive income to net income (1) — 105 105 Net current period other comprehensive income 30,465 11,359 41,824 Balance at December 31, 2016 $ 21,074 $ 5,883 $ 26,957 (1) Amounts reclassified from cumulative other comprehensive income (loss) is included in equity in earnings of investees in our consolidated statements of comprehensive income (loss).

Equity Investment in Select Inc

Equity Investment in Select Income REIT	12 Months Ended
	Dec. 31, 2016
Equity Method Investments and Joint Ventures [Abstract]
Equity Investment in Select Income REIT	Equity Investment in Select Income REIT As described in Note 7 , as of December 31, 2016 , we owned 24,918,421 , or approximately 27.9% , of the then outstanding SIR common shares. SIR is a REIT which primarily owns single tenant, net leased properties. We account for our investment in SIR under the equity method. Under the equity method, we record our proportionate share of SIR’s net income as equity in earnings of an investee in our consolidated statements of comprehensive income (loss). During the years ended December 31, 2016 and 2015 , and the period from July 9, 2014, the date of our initial investment in SIR, to December 31, 2014 , we recorded $35,381 , $21,882 and $17,113 of equity in earnings of SIR, respectively. Our other comprehensive income (loss) includes our proportionate share of SIR’s unrealized gains (losses) of $11,207 , ($5,493) and ($14) for the years ended December 31, 2016 and 2015 and the period from July 9, 2014 to December 31, 2014, respectively. As of December 31, 2016 , our investment in SIR had a carrying value of $487,708 and a market value, based on the closing price of SIR common shares on Nasdaq on December 31, 2016 , of $627,944 . We periodically evaluate our equity investment in SIR 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 the market value of our investment is below our cost basis, the financial condition of SIR, 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 may record an impairment charge to adjust the basis of the investment to its fair value. During years ended December 31, 2016 and 2015 and the period from July 9, 2014 to December 31, 2014, SIR issued 65,900 , 29,414,279 and 67,947 common shares, respectively. We recognized a gain (loss) on issuance of shares by SIR of $86 , ($42,145) and ($53) , respectively, during the years ended December 31, 2016 and 2015 and the period from July 9, 2014 to December 31, 2014 as a result of the per share issuance price of these SIR common shares being above (below) the then average per share carrying value of our SIR common shares. The cost of our investments in SIR exceeded our proportionate share of SIR’s total shareholders’ equity book value on their dates of acquisition by an aggregate of $166,272 . As required under GAAP, we were amortizing this difference to equity in earnings of investees over the average remaining useful lives of the real estate assets and intangible assets and liabilities owned by SIR as of the respective dates of our acquisitions. This amortization decreased our equity in the earnings of SIR by $4,742 and $6,237 for the years ended December 31, 2015 and 2014 , respectively. We recorded a loss on impairment of $203,297 of our SIR investment during the second quarter of 2015 resulting in the carrying value of our SIR investment being less than our proportionate share of SIR’s total shareholders’ equity book value as of June 30, 2015. As a result, the previous basis difference was eliminated and as of December 31, 2016 , we are accreting a basis difference of ($90,186) to earnings over the estimated remaining useful lives of the real estate assets and intangible assets and liabilities owned by SIR as of June 30, 2015. This accretion increased our equity in the earnings of SIR by $2,956 and $1,480 for the years ended December 31, 2016 and 2015 , respectively. During years ended December 31, 2016 and 2015 and the period from July 9, 2014 to December 31, 2014, we received cash distributions from SIR totaling $50,335 , $47,030 and $20,640 , respectively. In addition, during the year ended December 31, 2015, we received from SIR a non-cash distribution of 441,056 shares of RMR Inc. class A common stock valued at $5,244 . The following summarized financial data of SIR as reported in SIR’s Annual Report on Form 10-K for the year ended December 31, 2016 , or the SIR Annual Report, includes the financial position and results of operations for periods prior to July 9, 2014 (the date on which we acquired our initial interest in SIR). References in our financial statements to the SIR Annual Report are included as references to the source of the data only, and the information in the SIR Annual Report is not incorporated by reference into our financial statements. Consolidated Balance Sheets December 31, December 31, 2016 2015 Real estate properties, net $ 3,899,792 $ 3,954,889 Acquired real estate leases, net 506,298 566,195 Cash and cash equivalents 22,127 17,876 Rents receivable, net 124,089 99,307 Other assets, net 87,376 46,078 Total assets $ 4,639,682 $ 4,684,345 Unsecured revolving credit facility $ 327,000 $ 303,000 Unsecured term loan, net 348,373 347,876 Senior unsecured notes, net 1,430,300 1,426,025 Mortgage notes payable, net 245,643 286,706 Assumed real estate lease obligations, net 77,622 86,495 Other liabilities 136,782 137,283 Shareholders' equity 2,073,962 2,096,960 Total liabilities and shareholders' equity $ 4,639,682 $ 4,684,345 Consolidated Statements of Income Year Ended December 31, 2016 2015 2014 Rental income $ 387,015 $ 364,139 $ 189,743 Tenant reimbursements and other income 74,992 64,226 32,937 Total revenues 462,007 428,365 222,680 Real estate taxes 42,879 37,460 22,202 Other operating expenses 52,957 41,953 18,597 Depreciation and amortization 133,762 122,906 41,054 Acquisition related costs 306 21,987 7,348 General and administrative 28,602 25,859 14,881 Loss on asset impairment 5,484 — — Total expenses 263,990 250,165 104,082 Operating income 198,017 178,200 118,598 Dividend income 1,268 1,666 — Interest expense (82,620 ) (73,885 ) (12,974 ) Gain (loss) on early extinguishment of debt — (6,845 ) 243 Loss on distribution of The RMR Group Inc. common stock — (23,717 ) — Income before income tax expense and equity in earnings of an investee and gain on sale of property 116,665 75,419 105,867 Income tax expense (448 ) (515 ) (175 ) Equity in earnings of an investee 137 20 87 Net income before gain on sale of property 116,354 74,924 105,779 Gain on sale of property — — 116 Net income 116,354 74,924 105,895 Net income allocated to noncontrolling interest (33 ) (176 ) — Net income attributed to SIR $ 116,321 $ 74,748 $ 105,895 Weighted average common shares outstanding (basic) 89,304 86,699 55,964 Weighted average common shares outstanding (diluted) 89,324 86,708 56,035 Net income attributed to SIR per common share (basic and diluted) $ 1.30 $ 0.86 $ 1.89

Segment Information

Segment Information	12 Months Ended
	Dec. 31, 2016
Segment Reporting [Abstract]
Segment Information	Segment Information We operate in two business segments: ownership of properties that are primarily leased to government tenants and our equity method investment in SIR: Year Ended December 31, 2016 Investment in Real Estate Investment in SIR Corporate Consolidated Rental income $ 258,180 $ — $ — $ 258,180 Expenses: Real estate taxes 30,703 — — 30,703 Utility expenses 17,269 — — 17,269 Other operating expenses 54,290 — — 54,290 Depreciation and amortization 73,153 — — 73,153 Acquisition related costs 1,191 — — 1,191 General and administrative — — 14,897 14,897 Total expenses 176,606 — 14,897 191,503 Operating income (loss) 81,574 — (14,897 ) 66,677 Dividend income — — 971 971 Interest income 124 — 34 158 Interest expense (2,375 ) — (42,685 ) (45,060 ) Gain on early extinguishment of debt 104 — — 104 Net gain on issuance of shares by Select Income REIT — 86 — 86 Income (loss) from continuing operations before income taxes and equity in earnings (losses) of investees 79,427 86 (56,577 ) 22,936 Income tax expense — — (101 ) (101 ) Equity in earnings of investees — 35,381 137 35,518 Income (loss) from continuing operations 79,427 35,467 (56,541 ) 58,353 Loss from discontinued operations (589 ) — — (589 ) Income (loss) before gain on sale of property 78,838 35,467 (56,541 ) 57,764 Gain on sale of property 79 — — 79 Net income (loss) $ 78,917 $ 35,467 $ (56,541 ) $ 57,843 As of December 31, 2016 Investment in Real Estate Investment in SIR Corporate Consolidated Total Assets $ 1,807,560 $ 487,708 $ 89,798 $ 2,385,066 Year Ended December 31, 2015 Investment in Real Estate Investment in SIR Corporate Consolidated Rental income $ 248,549 $ — $ — $ 248,549 Expenses: Real estate taxes 29,906 — — 29,906 Utility expenses 17,916 — — 17,916 Other operating expenses 50,425 — — 50,425 Depreciation and amortization 68,696 — — 68,696 Acquisition related costs 561 — 250 811 General and administrative — — 14,826 14,826 Total expenses 167,504 — 15,076 182,580 Operating income (loss) 81,045 — (15,076 ) 65,969 Dividend income — — 811 811 Interest income 10 — 4 14 Interest expense (7,908 ) — (29,100 ) (37,008 ) Gain on early extinguishment of debt 34 — — 34 Loss on distribution to common shareholders of The RMR Group Inc. common stock — — (12,368 ) (12,368 ) Net loss on issuance of shares by Select Income REIT — (42,145 ) — (42,145 ) Loss on impairment of Select Income REIT investment — (203,297 ) — (203,297 ) Income (loss) from continuing operations before income taxes and equity in earnings of investees 73,181 (245,442 ) (55,729 ) (227,990 ) Income tax expense — — (86 ) (86 ) Equity in earnings of investees — 18,620 20 18,640 Income (loss) from continuing operations 73,181 (226,822 ) (55,795 ) (209,436 ) Loss from discontinued operations (525 ) — — (525 ) Net income (loss) $ 72,656 $ (226,822 ) $ (55,795 ) $ (209,961 ) As of December 31, 2015 Investment in Real Estate Investment in SIR Corporate Consolidated Total Assets $ 1,639,462 $ 491,369 $ 37,679 $ 2,168,510 Year ended December 31, 2014 Investment Investment in Real Estate in SIR Corporate Consolidated Rental income $ 251,031 $ — $ — $ 251,031 Expenses: Real estate taxes 28,389 — — 28,389 Utility expenses 19,369 — — 19,369 Other operating expenses 45,982 — — 45,982 Depreciation and amortization 66,593 — — 66,593 Loss on impairment of real estate 2,016 — — 2,016 Acquisition related costs 1,344 — — 1,344 General and administrative — — 15,809 15,809 Total expenses 163,693 — 15,809 179,502 Operating income (loss) 87,338 — (15,809 ) 71,529 Interest and other income — — 69 69 Interest expense (7,820 ) — (20,228 ) (28,048 ) Loss on early extinguishment of debt — — (1,307 ) (1,307 ) Loss on issuance of shares by Select Income REIT — (53 ) (53 ) Income (loss) from continuing operations before income taxes and equity in earnings of investees 79,518 (53 ) (37,275 ) 42,190 Income tax expense — — (117 ) (117 ) Equity in earnings of investees — 10,876 87 10,963 Income (loss) from continuing operations 79,518 10,823 (37,305 ) 53,036 Income from discontinued operations 3,498 — — 3,498 Net income (loss) $ 83,016 $ 10,823 $ (37,305 ) $ 56,534 As of December 31, 2014 Investment Investment in Real Estate in SIR Corporate Consolidated Total Assets $ 1,713,361 $ 680,137 $ 26,410 $ 2,419,908

Selected Quarterly Financial Da

Selected Quarterly Financial Data (Unaudited)	12 Months Ended
	Dec. 31, 2016
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 2016 and 2015 . 2016 First Second Third Fourth Rental income $ 63,611 $ 64,061 $ 64,478 $ 66,030 Net income 17,387 16,813 11,578 12,065 Net income per common share (basic and diluted) 0.24 0.24 0.16 0.17 Common distributions declared 0.43 0.43 0.43 0.43 2015 First Second Third Fourth Rental income $ 62,659 $ 62,113 $ 62,092 $ 61,685 Net income (loss) (33,370 ) (191,163 ) 16,911 (2,339 ) Net income (loss) per common share (basic and diluted) (0.47 ) (2.71 ) 0.24 (0.03 ) Common distributions declared (1) 0.43 0.43 0.43 0.56 (1) The fourth quarter of 2015 includes a non-cash distribution of $0.13 per share related to the distribution of RMR Inc. shares to our shareholders on December 14, 2015.

SCHEDULE III REAL ESTATE AND AC

SCHEDULE III REAL ESTATE AND ACCUMULATED DEPRECIATION	12 Months Ended
	Dec. 31, 2016
SEC Schedule III, 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 Encumbrances Land Buildings Impairments/ Land Buildings Total (1)(2) Accumulated (3) Date(s) Original 1 131 Clayton Street Montgomery, AL $ — $ 920 $ 9,084 $ 16 $ — $ 920 $ 9,100 $ 10,020 $ (1,251 ) 6/22/2011 2007 2 4344 Carmichael Road Montgomery, AL — 1,374 11,658 — — 1,374 11,658 13,032 (874 ) 12/17/2013 2009 3 15451 North 28th Avenue Phoenix, AZ — 1,917 7,416 67 — 1,917 7,483 9,400 (434 ) 9/10/2014 1996 4 711 14th Avenue Safford, AZ — 460 11,708 265 — 460 11,973 12,433 (1,924 ) 6/16/2010 1992 5 5045 East Butler Street Fresno, CA — 7,277 61,118 58 — 7,277 61,175 68,452 (21,968 ) 8/29/2002 1971 6 10949 N. Mather Boulevard Rancho Cordova, CA — 562 16,923 100 — 562 17,023 17,585 (1,341 ) 10/30/2013 2012 7 11020 Sun Center Drive Rancho Cordova, CA — 1,465 8,537 — — 1,465 8,537 10,002 — 12/20/2016 1983 8 801 K Street Sacramento, CA — 4,688 61,722 3,368 — 4,688 65,090 69,778 (1,425 ) 1/29/2016 1989 9 9800 Goethe Road Sacramento, CA — 1,550 12,263 1,520 — 1,550 13,783 15,333 (2,773 ) 12/23/2009 1993 10 9815 Goethe Road Sacramento, CA — 1,450 9,465 1,523 — 1,450 10,988 12,438 (1,444 ) 9/14/2011 1992 11 Capitol Place Sacramento, CA — 2,290 35,891 5,695 — 2,290 41,586 43,876 (6,858 ) 12/17/2009 1988 12 4181 Ruffin Road San Diego, CA — 5,250 10,549 3,737 — 5,250 14,286 19,536 (2,738 ) 7/16/2010 1981 13 4560 Viewridge Road San Diego, CA — 4,269 18,316 2,795 — 4,347 21,033 25,380 (9,234 ) 3/31/1997 1996 14 Sky Park Centre San Diego, CA — 685 5,530 1,689 — 685 7,219 7,904 (2,205 ) 6/24/2002 1986 15 Turning Basin Business Park Stockton, CA — 563 5,469 — — 563 5,469 6,032 (604 ) 7/20/2012 2012 16 16194 West 45th Street Golden, CO — 495 152 6,457 — 495 6,608 7,103 (3,121 ) 3/31/1997 1997 17 12795 West Alameda Parkway Lakewood, CO 5,218 2,640 23,777 1,045 — 2,640 24,822 27,462 (4,303 ) 1/15/2010 1988 18 Corporate Center Lakewood, CO — 2,887 27,538 3,850 — 2,887 31,386 34,273 (10,667 ) 10/11/2002 1980 19 20 Massachusetts Avenue Washington, DC — 12,005 51,528 20,952 — 12,228 72,261 84,489 (31,369 ) 3/31/1997 1996 20 625 Indiana Avenue Washington, DC — 26,000 25,955 5,799 — 26,000 31,754 57,754 (5,233 ) 8/17/2010 1989 21 7850 Southwest 6th Court Plantation, FL — 4,800 30,592 383 — 4,800 30,975 35,775 (4,421 ) 5/12/2011 1999 22 8900 Grand Oak Circle Tampa, FL 8,778 1,100 11,773 169 — 1,100 11,942 13,042 (1,866 ) 10/15/2010 1994 23 181 Spring Street NW Atlanta, GA — 5,718 20,017 131 — 5,718 20,147 25,865 (2,210 ) 7/25/2012 2007 24 Corporate Square Atlanta, GA — 3,996 29,762 9,952 — 3,996 39,714 43,710 (10,410 ) 7/16/2004 1967 25 Executive Park Atlanta, GA — 1,521 11,826 3,869 — 1,521 15,695 17,216 (4,478 ) 7/16/2004 1972 26 One Georgia Center Atlanta, GA — 10,250 27,933 882 — 10,250 28,815 39,065 (3,759 ) 9/30/2011 1968 27 4712 Southpark Boulevard Ellenwood, GA — 1,390 19,635 35 — 1,390 19,670 21,060 (2,168 ) 7/25/2012 2005 28 South Vinnell Way Boise, ID — 3,390 29,026 793 — 3,390 29,819 33,209 (3,252 ) 9/11/2012 1996; 1997; 2002 Initial Cost to Company Costs Capitalized Subsequent to Acquisition Cost amount carried at Close of Period Property Location Encumbrances Land Buildings Impairments/ Land Buildings Total (1)(2) Accumulated (3) Date(s) Original 29 2020 S. Arlington Heights Arlington Heights, IL — 1,450 13,160 926 — 1,450 14,086 15,536 (2,591 ) 12/29/2009 1988 30 Intech Park Indianapolis, IN — 4,170 68,888 2,886 — 4,170 71,774 75,944 (9,620 ) 10/14/2011 2000; 2001; 2008 31 400 State Street Kansas City, KS — 640 9,932 3,108 — 640 13,040 13,680 (1,992 ) 6/16/2010 1971 32 7125 Industrial Road Florence, KY — 1,698 11,722 17 — 1,698 11,739 13,437 (1,174 ) 12/31/2012 1980 33 251 Causeway Street Boston, MA — 5,100 17,293 1,336 — 5,100 18,629 23,729 (2,858 ) 8/17/2010 1987 34 75 Pleasant Street Malden, MA — 1,050 31,086 132 — 1,050 31,218 32,268 (5,168 ) 5/24/2010 2008 35 25 Newport Avenue Quincy, MA — 2,700 9,199 809 — 2,700 10,008 12,708 (1,391 ) 2/16/2011 1985 36 One Montvale Avenue Stoneham, MA — 1,670 11,035 1,599 — 1,670 12,634 14,304 (1,941 ) 6/16/2010 1945 37 4201 Patterson Avenue Baltimore, MD — 901 8,097 3,472 — 901 11,568 12,469 (4,103 ) 10/15/1998 1989 38 20400 Century Boulevard Germantown, MD — 2,306 9,890 538 — 2,347 10,386 12,733 (5,023 ) 3/31/1997 1995 39 3300 75th Avenue Landover, MD — 4,110 36,371 607 — 4,110 36,978 41,088 (6,311 ) 2/26/2010 1985 40 1401 Rockville Pike Rockville, MD — 3,248 29,258 15,797 — 3,248 45,058 48,306 (15,204 ) 2/2/1998 1986 41 2115 East Jefferson Street Rockville, MD — 3,349 11,152 271 — 3,349 11,423 14,772 (939 ) 8/27/2013 1981 42 Rutherford Business Park Windsor Mill, MD — 1,598 10,219 — — 1,598 10,219 11,817 (1,043 ) 11/16/2012 1972 43 Meadows Business Park Woodlawn, MD — 3,735 21,509 902 — 3,735 22,411 26,146 (3,232 ) 2/15/2011 1973 44 11411 E. Jefferson Avenue Detroit, MI — 630 18,002 23 — 630 18,025 18,655 (3,001 ) 4/23/2010 2009 45 330 South Second Avenue Minneapolis, MN — 3,991 18,186 9,534 — 3,991 27,719 31,710 (4,474 ) 7/16/2010 1980 46 Rosedale Corporate Plaza Roseville, MN — 672 6,045 1,465 — 672 7,510 8,182 (2,915 ) 12/1/1999 1987 47 1300 Summit Street Kansas City, MO — 2,776 12,070 227 — 2,776 12,297 15,073 (1,303 ) 9/27/2012 1998 48 4241-4300 NE 34th Street Kansas City, MO — 1,443 6,193 2,930 — 1,780 8,786 10,566 (3,654 ) 3/31/1997 1995 49 1220 Echelon Parkway Jackson, MS — 440 25,458 48 — 440 25,506 25,946 (2,820 ) 7/25/2012 2009 50 10-12 Celina Avenue Nashua, NH — 3,000 14,052 439 — 3,000 14,491 17,491 (2,642 ) 8/31/2009 1979 51 50 West State Street Trenton, NJ — 5,000 38,203 1,864 — 5,000 40,067 45,067 (5,918 ) 12/30/2010 1989 52 435 Montano Boulevard Albuquerque, NM — 710 1,651 57 — 710 1,708 2,418 (271 ) 7/16/2010 1986 53 138 Delaware Avenue Buffalo, NY — 4,405 18,899 5,010 — 4,485 23,829 28,314 (10,308 ) 3/31/1997 1994 54 Airline Corporate Center Colonie, NY — 790 6,400 13 — 790 6,413 7,203 (720 ) 6/22/2012 2004 55 5000 Corporate Court Holtsville, NY — 6,530 17,711 2,179 — 6,530 19,890 26,420 (2,585 ) 8/31/2011 2000 56 305 East 46th Street New York, NY — 36,800 66,661 3,596 — 36,800 70,257 107,057 (9,436 ) 5/27/2011 1928 Initial Cost to Company Costs Capitalized Subsequent to Acquisition Cost amount carried at Close of Period Property Location Encumbrances Land Buildings Impairments/ Land Buildings Total (1)(2) Accumulated (3) Date(s) Original 57 4600 25th Avenue Salem, OR — 6,510 17,973 4,187 — 6,510 22,160 28,670 (3,264 ) 12/20/2011 1957 58 Synergy Business Park Columbia, SC — 1,439 11,143 4,751 — 1,439 15,894 17,333 (3,108 ) 5/10/2006; 9/17/2010 1982; 1985 59 One Memphis Place Memphis, TN — 1,630 5,645 2,421 — 1,630 8,066 9,696 (1,168 ) 9/17/2010 1985 60 701 Clay Road Waco, TX — 2,030 8,708 2,779 — 2,060 11,457 13,517 (4,675 ) 12/23/1997 1997 61 14660, 14672 & 14668 Lee Road Chantilly, VA — 6,974 74,116 — — 6,974 74,116 81,090 — 12/22/2016 1998; 2002; 2006 62 Enterchange at Meadowville Chester, VA — 1,478 9,594 256 — 1,478 9,850 11,328 (813 ) 8/28/2013 1999 63 3920 Pender Drive Fairfax, VA — 2,963 12,840 11 — 2,963 12,852 15,815 (883 ) 3/21/2014 1981 64 Pender Business Park Fairfax, VA 13,841 2,529 21,386 189 — 2,529 21,575 24,104 (1,773 ) 11/4/2013 2000 65 1759 & 1760 Business Center Drive Reston, VA — 9,066 78,658 1,906 — 9,066 80,564 89,630 (5,137 ) 5/28/2014 1987 66 9960 Mayland Drive Richmond, VA — 2,614 15,930 1,244 — 2,614 17,174 19,788 (1,066 ) 5/20/2014 1994 67 Aquia Commerce Center Stafford, VA — 2,090 7,465 730 — 2,090 8,195 10,285 (1,070 ) 6/22/2011 1988; 1999 68 65 Bowdoin Street S. Burlington, VT — 700 8,416 120 — 700 8,536 9,236 (1,439 ) 4/9/2010 2009 69 840 North Broadway Everett, WA — 3,360 15,376 1,346 — 3,360 16,722 20,082 (1,933 ) 6/28/2012 1985 70 Stevens Center Richland, WA — 3,970 17,035 1,606 — 4,042 18,569 22,611 (8,640 ) 3/31/1997 1995 71 11050 West Liberty Drive Milwaukee, WI — 945 4,539 103 — 945 4,642 5,587 (645 ) 6/9/2011 2006 72 2029 Stonewall Jackson Drive Falling Waters, WV — 906 3,886 270 — 922 4,140 5,062 (2,005 ) 3/31/1997 1993 73 5353 Yellowstone Road Cheyenne, WY — 1,915 8,217 531 — 1,950 8,713 10,663 (4,218 ) 3/31/1997 1995 $ 27,837 $ 266,943 $ 1,464,432 $ 157,385 $ — $ 267,855 $ 1,620,905 $ 1,888,760 $ (296,804 ) Assets Discontinued Operations 74 5600 Columbia Pike Falls Church, VA — 3,519 15,098 4,065 (10,423 ) 3,044 9,216 12,260 — 3/31/1997 1993 $ 27,837 $ 270,462 $ 1,479,530 $ 161,450 $ (10,423 ) $ 270,899 $ 1,630,121 $ 1,901,020 $ (296,804 ) ____________________ (1) Represents mortgage debt, net of the unamortized balance of the fair value adjustments and debt issuance costs totaling $329 . (2) Excludes value of real estate intangibles. Aggregate cost for federal income tax purposes is approximately $2,223,207 . (3) Depreciation on building and improvements is provided for periods ranging up to 40 years and on equipment up to 12 years . Analysis of the carrying amount of real estate properties and accumulated depreciation: Real Estate Properties Accumulated Depreciation Balance at December 31, 2013 $ 1,568,562 $ 187,635 Additions 151,316 37,671 Loss on asset impairment (7,058 ) (5,071 ) Disposals (444 ) (444 ) Reclassification of assets held for sale (29,896 ) — Balance at December 31, 2014 1,682,480 219,791 Additions 19,622 38,987 Disposals (2,624 ) (2,624 ) Reclassification of assets held for sale (3,346 ) (275 ) Balance at December 31, 2015 1,696,132 255,879 Additions 194,107 42,404 Disposals (1,479 ) (1,479 ) Balance at December 31, 2016 $ 1,888,760 $ 296,804

Summary of Significant Accoun23

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2016
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 100% owned directly or indirectly by us. All intercompany transactions and balances with or among our consolidated subsidiaries have been eliminated.
Real Estate Properties	Real Estate Properties. We record our properties at cost and provide depreciation on real estate investments on a straight line basis over estimated useful lives generally ranging from 7 to 40 years. In some circumstances, we engage independent real estate appraisal firms to provide market information and evaluations which are relevant to our purchase price allocations and determinations of useful lives; however, we are ultimately responsible for the purchase price allocations and determinations of useful lives. We allocate the purchase prices of our properties to land, building and improvements based on determinations of the 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. For properties qualifying as acquired businesses under Accounting Standards Codification 805, Business Combinations , 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. We amortize capitalized above market lease values (included in acquired in place real estate leases in our consolidated balance sheets) and below market lease values (presented as assumed real estate lease obligations 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 $1,457 , $1,155 , and $868 during the years ended December 31, 2016 , 2015 and 2014 , respectively. We amortize the value of acquired in place leases (included in acquired real estate leases 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 $27,546 , $27,467 , and $26,844 during the years ended December 31, 2016 , 2015 and 2014 , respectively. When a lease is terminated prior to its stated expiration, we write off the unamortized amounts relating to that lease. Capitalized above market lease values were $39,261 and $37,875 as of December 31, 2016 and 2015 , respectively, net of accumulated amortization of $22,753 and $21,469 , respectively. Capitalized below market lease values were $20,603 and $25,553 as of December 31, 2016 and 2015 , respectively, net of accumulated amortization of $9,977 and $12,818 , respectively. The value of acquired in place leases, exclusive of the value of above market and below market acquired in place leases, was $203,368 and $188,471 as of December 31, 2016 and 2015 , respectively, net of accumulated amortization of $95,028 and $86,610 , respectively. As of December 31, 2016 , the weighted average amortization periods for capitalized above market leases, lease origination value and capitalized below market lease values were 4.4 years, 5.0 years and 6.7 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, 2016 are estimated to be $33,578 in 2017 , $28,828 in 2018 , $19,853 in 2019 , $10,478 in 2020 , $7,959 in 2021 and $13,526 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. 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. Equity Method Investments. We account for our investments in Affiliates Insurance Company, or AIC, and SIR using the equity method of accounting. Significant influence is present through common representation on the boards of trustees or directors of us, AIC and SIR and our significant ownership interest in SIR. Our Managing Trustees are also the managing trustees of SIR. Our Managing Trustees are also directors, officers and controlling shareholders (through ABP Trust) of The RMR Group Inc., or RMR Inc. Substantially all of the business of RMR Inc. is conducted by its majority owned subsidiary, The RMR Group LLC, or RMR LLC, which is the manager of us, AIC and SIR. Each of our Trustees is a director of AIC and one of our Independent Trustees is also an independent trustee of SIR. See Notes 7 and 12 for a further discussion of our investments in AIC and SIR. 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. We recorded a $203,297 loss on impairment of our SIR investment in 2015 . See Note 12 for more information on this impairment
Equity Method Investments	Equity Method Investments. We account for our investments in Affiliates Insurance Company, or AIC, and SIR using the equity method of accounting. Significant influence is present through common representation on the boards of trustees or directors of us, AIC and SIR and our significant ownership interest in SIR. Our Managing Trustees are also the managing trustees of SIR. Our Managing Trustees are also directors, officers and controlling shareholders (through ABP Trust) of The RMR Group Inc., or RMR Inc. Substantially all of the business of RMR Inc. is conducted by its majority owned subsidiary, The RMR Group LLC, or RMR LLC, which is the manager of us, AIC and SIR. Each of our Trustees is a director of AIC and one of our Independent Trustees is also an independent trustee of SIR. See Notes 7 and 12 for a further discussion of our investments in AIC and SIR. 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. We recorded a $203,297 loss on impairment of our SIR investment in 2015 . See Note 12 for more information on this impairment.
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.
Revenue Recognition	Revenue Recognition. We recognize rental income from operating leases that contain fixed contractual rent changes on a straight line basis over the term of the lease agreements. We increased rental income by $2,691 , $3,978 and $4,495 to record revenue on a straight line basis during the years ended December 31, 2016 , 2015 and 2014 , respectively. Rents receivable include $21,686 and $18,995 of straight line rent receivables at December 31, 2016 and 2015 , respectively. Certain of our leases with government tenants provide the tenant the right to terminate its lease if its respective legislature or other funding authority does not appropriate the funding necessary for the government tenant to meet its lease obligations; we have determined the fixed non-cancelable lease term of these leases to be the fully executed term of the lease because we believe the occurrence of termination to be a remote contingency based on both our historical experience and our assessment of the likelihood of lease cancellation on a separate lease basis.
Deferred Leasing Costs	Deferred Leasing Costs . Deferred leasing costs include brokerage, legal and other fees associated with our entering leases and we amortize those costs, which are included in depreciation and amortization expense, on a straight line basis over the terms of the respective leases. Deferred leasing costs totaled $28,039 and $20,300 at December 31, 2016 and 2015 , respectively, and accumulated amortization of deferred leasing costs totaled $6,960 and $6,001 at December 31, 2016 and 2015 , respectively. Future amortization of deferred leasing costs to be recognized during the current terms of our existing leases as of December 31, 2016 , are estimated to be $3,598 in 2017 , $3,279 in 2018 , $3,115 in 2019 , $2,521 in 2020 , $2,086 in 2021 and $6,480 thereafter.
Available for Sale Securities	Available for Sale Securities. As of December 31, 2016 , we owned 1,214,225 common shares of class A common stock of RMR Inc. Our investment in RMR Inc. is classified as an available for sale security. Available for sale securities are recorded at fair value based on their quoted market price at the end of each reporting period. Unrealized gains and losses on available for sale securities are recorded as a component of cumulative other comprehensive income (loss) in shareholders’ equity. As further described in Note 7 , 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 and $1,268 of this liability during the years ended December 31, 2016 and 2015, respectively. These amounts are included in the net business management and property management fee amounts for such periods. As of December 31, 2016, the remaining unamortized amount of this liability was $20,667 . We evaluate our investments in available for sale securities to determine if a decline in the fair value below our carrying value is other than temporary. We consider the severity and the duration of the decline, and our ability and intent to hold the investment until recovery when making this assessment. If a decline in fair value is determined to be other than temporary, an impairment loss equal to the difference between the investment’s carrying value and its fair value is recognized in earnings.
Deferred 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, 2016 and 2015 , debt issuance costs for our revolving credit facility were $5,234 and $5,234 , respectively, and accumulated amortization of debt issuance costs for our revolving credit facility were $2,617 and $1,385 , respectively. Debt issuance costs, net of accumulated amortization, for our unsecured 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.
Income Taxes	Income Taxes. We have elected to be taxed as a REIT under the United States Internal Revenue Code of 1986, as amended, or the IRC, 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 as a REIT. We are, however, subject to certain state and local taxes.
Cumulative Other Comprehensive Income (Loss)	Cumulative Other Comprehensive Income (Loss). Cumulative other comprehensive income (loss) represents the unrealized gain (loss) on the RMR Inc. shares we own and our share of the cumulative comprehensive income (loss) of our equity method investees, SIR and AIC. See Notes 2, 7 and 12 for further information regarding these investments.
Reclassifications	Reclassifications. Certain reclassifications have been made to the prior years’ financial statements to conform to the current year’s presentation.
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.
Per Common Share Amounts	Per Common Share Amounts. We calculate basic earnings per common share by dividing net income (loss) 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.
Segment Reporting	Segment Reporting. We operate in two business segments: ownership of properties that are primarily leased to government tenants and our equity method investment in SIR.
Recent Accounting Pronouncements	Recent Accounting Pronouncements On January 1, 2016, we adopted the Financial Accounting Standards Board, or FASB, Accounting Standards Update, or ASU, No. 2015-02, Consolidation . Among other things, this update changes how an entity determines the primary beneficiary of a variable interest entity. The implementation of this update did not have an impact in our consolidated financial statements. On January 1, 2016, we adopted FASB ASU No. 2015-03, Simplifying the Presentation of Debt Issuance Costs , which requires debt issuance costs to be presented in the balance sheet as a direct deduction from the associated debt liability, and FASB ASU No. 2015-15, Presentation and Subsequent Measurement of Debt Issuance Costs Associated with Line-of-Credit Arrangements —Amendments to SEC Paragraphs Pursuant to Staff Announcement at June 18, 2015 EITF Meeting , which addresses the presentation of debt issuance costs related to line of credit arrangements. The implementation of these updates resulted in the reclassification of certain of our capitalized debt issuance costs as an offset to the associated debt liability in our consolidated balance sheets. The classification of capitalized debt issuance costs related to our revolving credit facility remains unchanged in accordance with ASU No. 2015-15. As of December 31, 2015, debt issuance costs related to our unsecured term loans, senior unsecured notes and mortgage notes payable of $3,510 , $2,172 and $344 , respectively, were reclassified from assets to the associated debt liability in our consolidated balance sheets. On January 1, 2016, we adopted FASB ASU No. 2015-16, Simplifying the Accounting for Measurement-Period Adjustments , which eliminates the requirement for an acquirer in a business combination to account for measurement period adjustments retrospectively. Instead, acquirers must recognize measurement period adjustments during the period in which they determine the amounts, including the effect on earnings of any amounts they would have recorded in previous periods if the accounting had been completed at the acquisition date. The implementation of this update did not have an impact in our consolidated financial statements. On December 31, 2016, we adopted FASB ASU No. 2014-15, Presentation of Financial Statements—Going Concern : Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern . This update requires an entity to evaluate whether there are conditions or events that raise substantial doubt about the entity’s ability to continue as a going concern within one year after the date that the financial statements are issued (or within one year after the financial statements are available to be issued when applicable) and to provide related footnote disclosures in certain circumstances. The implementation of this update did not have an impact in our consolidated financial statements. In 2014, the FASB issued ASU No. 2014-09, Revenue From Contracts With Customers ("ASU 2014-09"), which outlines a comprehensive model for entities to use in accounting for revenue arising from contracts with customers. ASU No. 2014-09 states that “an entity recognizes revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services.” While ASU No. 2014-09 specifically references contracts with customers, it may apply to certain other transactions such as the sale of real estate or equipment. In 2015, the FASB provided for a one-year deferral of the effective date for ASU No. 2014-09, which is now effective for us beginning January 1, 2018. A substantial portion of our revenue consists of rental income from leasing arrangements, which is specifically excluded from ASU 2014-09. We are continuing to evaluate ASU No. 2014-09 (and related clarifying guidance issued by the FASB); however, we do not expect its adoption to have a significant impact on the timing of our revenue recognition in the consolidated financial statements with the exception of profit recognition on real estate sales. We currently have a deferred gain on sale of real estate of $712 that would have been recognized in 2021 or upon repayment of a promissory note we received in connection with the sale but will be recognized in its entirety upon adoption of the standard. In January 2016, the FASB issued ASU No. 2016-01, Recognition and Measurement of Financial Assets and Financial Liabilities , which changes how entities measure certain equity investments and present changes in the fair value of financial liabilities measured under the fair value option that are attributable to their own credit. This update is effective for interim and annual periods beginning after December 15, 2017, with early adoption permitted subject to certain conditions. Currently, changes in fair value of these investments are recorded through other comprehensive income (loss). ASU No. 2016-01 states that these changes will be recorded through earnings. We are continuing to evaluate this guidance, but we expect the implementation of this guidance will affect how changes in the fair value of available for sale securities we hold are presented in our consolidated financial statements. In February 2016, the FASB issued ASU No. 2016-02, Leases , which sets out the principles for the recognition, measurement, presentation and disclosure of leases for both parties to a contract (i.e., lessees and lessors). 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. A lessee is also required to record a right of use asset and a lease liability for all leases with a term of greater than 12 months regardless of their classification. Leases with a term of 12 months or less will be accounted for similar to existing guidance for operating leases today. The new standard requires lessors to account for leases using an approach that is substantially equivalent to existing guidance for sales type leases, direct financing leases and operating leases. ASU No. 2016-02 is effective for reporting periods beginning after December 15, 2018, with early adoption permitted. We are currently assessing the potential impact the adoption of ASU No. 2016-02 will have in our consolidated financial statements. In March 2016, the FASB issued ASU No. 2016-09, Compensation - Stock Compensation , which identifies areas for simplification involving several aspects of accounting for share based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, an option to recognize gross stock compensation expense with actual forfeitures recognized as they occur, as well as certain classifications on the statement of cash flows. ASU No. 2016-09 is effective for reporting periods beginning after December 31, 2016. We do not expect the adoption of ASU No. 2016-09 to have a material impact in our consolidated financial statements. 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 for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. We are currently assessing the potential impact that adoption of ASU No. 2016-13 will have in our consolidated financial statements. In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments , which clarifies how companies present and classify certain cash receipts and cash payments in the statement of cash flows. ASU No. 2016-15 is effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. We are currently assessing the potential impact that adoption of ASU No. 2016-15 will have in our consolidated financial statements. In November 2016, the FASB issued ASU No. 2016-18, Restricted Cash , which clarifies how companies should present restricted cash and restricted cash equivalents. Companies will show the changes in the total of cash, cash equivalents, restricted cash and restricted cash equivalents in the statement of cash flows. The new standard requires a reconciliation of the totals in the statement of cash flows to the related captions in the balance sheet. ASU No. 2016-18 is effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. We are currently assessing the potential impact that adoption of ASU No. 2016-18 will have in our consolidated financial statements. In January 2017, the FASB issued ASU No. 2017-01, Clarifying the Definition of a Business , which provides additional guidance on evaluating whether transactions should be accounted for as an acquisition (or disposal) of assets or of a business. The update defines three requirements for a set of assets and activities (collectively referred to as a “set”) to be considered a business: inputs, processes and outputs. ASU No. 2017-01 is effective for annual periods beginning after December 15, 2017, including interim periods within those fiscal years. This update will be applied prospectively to any transactions occurring within the period of adoption. We are currently assessing the impact of the update; however, subsequent to adoption we believe certain property acquisitions which under previous guidance would have been accounted for as business combinations will be accounted for as acquisitions of assets. In an acquisition of assets, certain acquisition costs are capitalized as opposed to expensed under business combination guidance.

Weighted Average Common Shares

Weighted Average Common Shares (Tables)	12 Months Ended
	Dec. 31, 2016
Earnings Per Share, Basic and Diluted [Abstract]
Weighted Average Common Share Amounts	The following table provides a reconciliation of the weighted average number of common shares used in the calculation of basic and diluted earnings per share (in thousands): For the Year Ended December 31, 2016 2015 2014 Weighted average common shares for basic earnings per share 71,050 70,700 61,313 Effect of dilutive securities: unvested share awards 21 — 86 Weighted average common shares for diluted earnings per share 71,071 70,700 61,399

Real Estate Properties (Tables)

Real Estate Properties (Tables)	12 Months Ended
	Dec. 31, 2016
Real Estate [Abstract]
Schedule of future minimum lease payments related properties (excluding real estate tax and other expense reimbursements)	Our future minimum lease payments related to our properties, excluding one property ( one building) classified as discontinued operations, and estimated real estate tax and other expense reimbursements scheduled to be received during the current terms of the existing leases as of December 31, 2016 are as follows: 2017 $ 242,867 2018 219,676 2019 190,106 2020 140,014 2021 118,815 Thereafter 364,419 $ 1,275,897
Schedule of allocation of purchase price	Our allocation of the purchase price of these acquisitions based on the estimated fair value of the acquired assets and assumed liabilities is presented in the table below. Number of Buildings Other Acquired Acquisition Properties/ Square Purchase and Assumed Acquired Lease Date Location Type Buildings Feet Price (1) Land Improvements Assets Leases Obligations 1/29/2016 Sacramento, CA (2) Office 1 / 1 337,811 $ 79,235 $ 4,688 $ 61,722 $ 2,167 $ 11,245 $ (587 ) 7/6/2016 Atlanta, GA (3) Land — — 1,670 1,670 — — — — 12/20/2016 Rancho Cordova, CA (2)(4) Office 1 / 1 82,896 13,943 1,465 8,537 — 3,941 — 12/22/2016 Chantilly, VA (2)(4) Office 1 / 3 409,478 104,183 6,974 74,116 — 23,093 — 3 / 5 830,185 $ 199,031 $ 14,797 $ 144,375 $ 2,167 $ 38,279 $ (587 ) (1) Excludes acquisition costs. (2) Accounted for as a business combination. (3) On July 6, 2016, we acquired a land parcel adjacent to on our existing properties for $1,623 . We accounted for this transaction as an asset acquisition and capitalized acquisition related costs of $47 . (4) The allocation of the purchase price is based on preliminary estimates and may change upon the completion of (i) third party valuations and (ii) our analysis of acquired in place lease and land and building valuations.
Summarized balance sheet information for properties classified as held for sale	Summarized balance sheet information for the property as of December 31, 2015 is as follows: December 31, 2015 Real estate properties, net $ 3,071 Rents receivable 1 Other assets 26 Assets of property held for sale $ 3,098 Other liabilities $ 43 Liabilities of property held for sale $ 43
Summarized balance sheet and income statement information for properties classified as discontinued operations	Summarized balance sheet and income statement information for the properties classified as discontinued operations is as follows: Balance Sheets December 31, December 31, 2016 2015 Real estate properties, net $ 12,260 $ 12,260 Other assets 281 208 Assets of discontinued operations $ 12,541 $ 12,468 Other liabilities $ 45 $ 54 Liabilities of discontinued operations $ 45 $ 54 Statements of Operations Year Ended December 31, 2016 2015 2014 Rental income $ 68 $ 114 $ 1,673 Real estate taxes (97 ) (92 ) (427 ) Utility expenses (146 ) (161 ) (226 ) Other operating expenses (300 ) (272 ) (459 ) General and administrative (114 ) (114 ) (181 ) Increase in carrying value of asset held for sale — — 2,344 Net gain on sale of properties — — 774 Income (loss) from discontinued operations $ (589 ) $ (525 ) $ 3,498

Indebtedness (Tables)

Indebtedness (Tables)	12 Months Ended
	Dec. 31, 2016
Debt Disclosure [Abstract]
Schedule of required principal payments	The required principal payments due during the next five years and thereafter under all our outstanding debt as of December 31, 2016 are as follows: Year Principal payment 2017 $ 1,549 2018 1,671 2019 519,439 2020 301,619 2021 13,230 Thereafter 560,000 $ 1,397,508 (1) (1) Total debt outstanding as of December 31, 2016 , net of unamortized premiums, discounts and certain issuance costs totaling $15,656 was $1,381,852 .

Fair Value of Assets and Liab27

Fair Value of Assets and Liabilities (Tables)	12 Months Ended
	Dec. 31, 2016
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 table below presents certain of our assets measured at fair value at December 31, 2016 , 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 Significant Estimated Active Markets for Significant Other Unobservable Fair Identical Assets Observable Inputs Inputs Description Value (Level 1) (Level 2) (Level 3) Recurring Fair Value Measurement Assets: Investment in RMR Inc. (1) $ 47,962 $ 47,962 $ — $ — Non-Recurring Fair Value Measurement Assets: Property held for sale and classified as discontinued operations (2) $ 12,260 $ — $ — $ 12,260 (1) Our 1,214,225 shares of class A common stock of RMR Inc., which are included in other assets in our consolidated balance sheets, are reported at fair value which is based on quoted market prices (Level 1 inputs). Our historical cost basis for these shares is $26,888 as of December 31, 2016 . The unrealized gain of $21,074 for these shares as of December 31, 2016 is included in cumulative other comprehensive income (loss) in our consolidated balance sheets. (2) We estimated the fair value of this property at December 31, 2016 based upon broker estimates of value less estimated sale costs (Level 3 inputs as defined in the fair value hierarchy under GAAP).
Schedule of fair value and carrying value of financial instruments	At December 31, 2016 and December 31, 2015 , the fair values of our financial instruments approximated their carrying values in our consolidated financial statements due to their short term nature or variable interest rates, except as follows: As of December 31, 2016 As of December 31, 2015 Carrying Amount (1) Fair Value Carrying Amount (1) Fair Value Senior unsecured notes, 3.75% interest rate, due in 2019 $ 346,952 $ 354,078 $ 345,809 $ 351,692 Senior unsecured notes, 5.875% interest rate, due in 2046 299,892 292,268 — — Mortgage note payable, 6.21% interest rate, due in 2016 (2) (3) — — 23,476 24,038 Mortgage note payable, 5.55% interest rate, due in 2016 (2) (4) — — 83,375 83,457 Mortgage note payable, 5.88% interest rate, due in 2021 (2) 13,841 14,492 14,045 14,678 Mortgage note payable, 7.00% interest rate, due in 2019 (2) 8,778 9,188 9,145 9,645 Mortgage note payable, 8.15% interest rate, due in 2021 (2) 5,218 5,575 6,258 6,711 $ 674,681 $ 675,601 $ 482,108 $ 490,221 (1) Carrying amount includes certain unamortized debt issuance costs and unamortized premiums and discounts. (2) We assumed these mortgages in connection with our acquisitions of the encumbered properties. The stated interest rates for these mortgage debts are the contractually stated rates. We recorded the assumed mortgages at estimated fair value on the date of acquisition and we are amortizing the fair value premiums, if any, to interest expense over the respective terms of the mortgages to reduce interest expense to the estimated market interest rates as of the date of acquisition. (3) This mortgage note was repaid, at par, in February 2016. (4) This mortgage note was repaid, at par, in March 2016.

Shareholders' Equity (Tables)

Shareholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2016
Equity [Abstract]
Summary of shares granted and vested under the terms of the entity's 2009 Plan	A summary of shares granted and vested under the terms of the 2009 Plan for the years ended December 31, 2016 , 2015 and 2014 , is as follows: 2016 2015 2014 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 shares, beginning of year 96,725 $20.11 90,338 $23.40 85,451 $23.71 Shares granted 65,900 21.66 65,600 16.59 63,650 23.70 Shared forfeited or repurchased — — (1,020 ) 23.41 — — Shares vested (63,655 ) 20.97 (58,193 ) 21.20 (58,763 ) 24.17 Unvested shares, end of year 98,970 $20.59 96,725 $20.11 90,338 $23.40
Schedule of changes in each component of cumulative other comprehensive income (loss)	The following table presents a roll forward of amounts recognized in cumulative other comprehensive income (loss) by component for the years ended December 31, 2016 , 2015 and 2014 : Unrealized Gain (Loss) on Investment in Available for Sale Securities Equity in Unrealized Gains (Losses) of Investees Total Balance at December 31, 2013 $ — $ 49 $ 49 Other comprehensive loss before reclassifications — 37 37 Amounts reclassified from cumulative other comprehensive loss to net income (1) — (49 ) (49 ) Net current period other comprehensive loss — (12 ) (12 ) Balance at December 31, 2014 — 37 37 Other comprehensive loss before reclassifications (9,391 ) (5,592 ) (14,983 ) Amounts reclassified from cumulative other comprehensive loss to net income (1) — 79 79 Net current period other comprehensive loss (9,391 ) (5,513 ) (14,904 ) Balance at December 31, 2015 (9,391 ) (5,476 ) (14,867 ) Other comprehensive income before reclassifications 30,465 11,254 41,719 Amounts reclassified from cumulative other comprehensive income to net income (1) — 105 105 Net current period other comprehensive income 30,465 11,359 41,824 Balance at December 31, 2016 $ 21,074 $ 5,883 $ 26,957 (1) Amounts reclassified from cumulative other comprehensive income (loss) is included in equity in earnings of investees in our consolidated statements of comprehensive income (loss).

Equity Investment in Select I29

Equity Investment in Select Income REIT (Tables)	12 Months Ended
	Dec. 31, 2016
SIR
Summarized Financial Data of Select Income Realty (SIR)	Consolidated Balance Sheets December 31, December 31, 2016 2015 Real estate properties, net $ 3,899,792 $ 3,954,889 Acquired real estate leases, net 506,298 566,195 Cash and cash equivalents 22,127 17,876 Rents receivable, net 124,089 99,307 Other assets, net 87,376 46,078 Total assets $ 4,639,682 $ 4,684,345 Unsecured revolving credit facility $ 327,000 $ 303,000 Unsecured term loan, net 348,373 347,876 Senior unsecured notes, net 1,430,300 1,426,025 Mortgage notes payable, net 245,643 286,706 Assumed real estate lease obligations, net 77,622 86,495 Other liabilities 136,782 137,283 Shareholders' equity 2,073,962 2,096,960 Total liabilities and shareholders' equity $ 4,639,682 $ 4,684,345 Consolidated Statements of Income Year Ended December 31, 2016 2015 2014 Rental income $ 387,015 $ 364,139 $ 189,743 Tenant reimbursements and other income 74,992 64,226 32,937 Total revenues 462,007 428,365 222,680 Real estate taxes 42,879 37,460 22,202 Other operating expenses 52,957 41,953 18,597 Depreciation and amortization 133,762 122,906 41,054 Acquisition related costs 306 21,987 7,348 General and administrative 28,602 25,859 14,881 Loss on asset impairment 5,484 — — Total expenses 263,990 250,165 104,082 Operating income 198,017 178,200 118,598 Dividend income 1,268 1,666 — Interest expense (82,620 ) (73,885 ) (12,974 ) Gain (loss) on early extinguishment of debt — (6,845 ) 243 Loss on distribution of The RMR Group Inc. common stock — (23,717 ) — Income before income tax expense and equity in earnings of an investee and gain on sale of property 116,665 75,419 105,867 Income tax expense (448 ) (515 ) (175 ) Equity in earnings of an investee 137 20 87 Net income before gain on sale of property 116,354 74,924 105,779 Gain on sale of property — — 116 Net income 116,354 74,924 105,895 Net income allocated to noncontrolling interest (33 ) (176 ) — Net income attributed to SIR $ 116,321 $ 74,748 $ 105,895 Weighted average common shares outstanding (basic) 89,304 86,699 55,964 Weighted average common shares outstanding (diluted) 89,324 86,708 56,035 Net income attributed to SIR per common share (basic and diluted) $ 1.30 $ 0.86 $ 1.89

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2016
Segment Reporting [Abstract]
Schedule of ownership of properties that are primarily leased to government tenants and our equity method investment in SIR	We operate in two business segments: ownership of properties that are primarily leased to government tenants and our equity method investment in SIR: Year Ended December 31, 2016 Investment in Real Estate Investment in SIR Corporate Consolidated Rental income $ 258,180 $ — $ — $ 258,180 Expenses: Real estate taxes 30,703 — — 30,703 Utility expenses 17,269 — — 17,269 Other operating expenses 54,290 — — 54,290 Depreciation and amortization 73,153 — — 73,153 Acquisition related costs 1,191 — — 1,191 General and administrative — — 14,897 14,897 Total expenses 176,606 — 14,897 191,503 Operating income (loss) 81,574 — (14,897 ) 66,677 Dividend income — — 971 971 Interest income 124 — 34 158 Interest expense (2,375 ) — (42,685 ) (45,060 ) Gain on early extinguishment of debt 104 — — 104 Net gain on issuance of shares by Select Income REIT — 86 — 86 Income (loss) from continuing operations before income taxes and equity in earnings (losses) of investees 79,427 86 (56,577 ) 22,936 Income tax expense — — (101 ) (101 ) Equity in earnings of investees — 35,381 137 35,518 Income (loss) from continuing operations 79,427 35,467 (56,541 ) 58,353 Loss from discontinued operations (589 ) — — (589 ) Income (loss) before gain on sale of property 78,838 35,467 (56,541 ) 57,764 Gain on sale of property 79 — — 79 Net income (loss) $ 78,917 $ 35,467 $ (56,541 ) $ 57,843 As of December 31, 2016 Investment in Real Estate Investment in SIR Corporate Consolidated Total Assets $ 1,807,560 $ 487,708 $ 89,798 $ 2,385,066 Year Ended December 31, 2015 Investment in Real Estate Investment in SIR Corporate Consolidated Rental income $ 248,549 $ — $ — $ 248,549 Expenses: Real estate taxes 29,906 — — 29,906 Utility expenses 17,916 — — 17,916 Other operating expenses 50,425 — — 50,425 Depreciation and amortization 68,696 — — 68,696 Acquisition related costs 561 — 250 811 General and administrative — — 14,826 14,826 Total expenses 167,504 — 15,076 182,580 Operating income (loss) 81,045 — (15,076 ) 65,969 Dividend income — — 811 811 Interest income 10 — 4 14 Interest expense (7,908 ) — (29,100 ) (37,008 ) Gain on early extinguishment of debt 34 — — 34 Loss on distribution to common shareholders of The RMR Group Inc. common stock — — (12,368 ) (12,368 ) Net loss on issuance of shares by Select Income REIT — (42,145 ) — (42,145 ) Loss on impairment of Select Income REIT investment — (203,297 ) — (203,297 ) Income (loss) from continuing operations before income taxes and equity in earnings of investees 73,181 (245,442 ) (55,729 ) (227,990 ) Income tax expense — — (86 ) (86 ) Equity in earnings of investees — 18,620 20 18,640 Income (loss) from continuing operations 73,181 (226,822 ) (55,795 ) (209,436 ) Loss from discontinued operations (525 ) — — (525 ) Net income (loss) $ 72,656 $ (226,822 ) $ (55,795 ) $ (209,961 ) As of December 31, 2015 Investment in Real Estate Investment in SIR Corporate Consolidated Total Assets $ 1,639,462 $ 491,369 $ 37,679 $ 2,168,510 Year ended December 31, 2014 Investment Investment in Real Estate in SIR Corporate Consolidated Rental income $ 251,031 $ — $ — $ 251,031 Expenses: Real estate taxes 28,389 — — 28,389 Utility expenses 19,369 — — 19,369 Other operating expenses 45,982 — — 45,982 Depreciation and amortization 66,593 — — 66,593 Loss on impairment of real estate 2,016 — — 2,016 Acquisition related costs 1,344 — — 1,344 General and administrative — — 15,809 15,809 Total expenses 163,693 — 15,809 179,502 Operating income (loss) 87,338 — (15,809 ) 71,529 Interest and other income — — 69 69 Interest expense (7,820 ) — (20,228 ) (28,048 ) Loss on early extinguishment of debt — — (1,307 ) (1,307 ) Loss on issuance of shares by Select Income REIT — (53 ) (53 ) Income (loss) from continuing operations before income taxes and equity in earnings of investees 79,518 (53 ) (37,275 ) 42,190 Income tax expense — — (117 ) (117 ) Equity in earnings of investees — 10,876 87 10,963 Income (loss) from continuing operations 79,518 10,823 (37,305 ) 53,036 Income from discontinued operations 3,498 — — 3,498 Net income (loss) $ 83,016 $ 10,823 $ (37,305 ) $ 56,534 As of December 31, 2014 Investment Investment in Real Estate in SIR Corporate Consolidated Total Assets $ 1,713,361 $ 680,137 $ 26,410 $ 2,419,908

Selected Quarterly Financial 31

Selected Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Schedule of Quarterly Financial Information	The following is a summary of our unaudited quarterly results of operations for 2016 and 2015 . 2016 First Second Third Fourth Rental income $ 63,611 $ 64,061 $ 64,478 $ 66,030 Net income 17,387 16,813 11,578 12,065 Net income per common share (basic and diluted) 0.24 0.24 0.16 0.17 Common distributions declared 0.43 0.43 0.43 0.43 2015 First Second Third Fourth Rental income $ 62,659 $ 62,113 $ 62,092 $ 61,685 Net income (loss) (33,370 ) (191,163 ) 16,911 (2,339 ) Net income (loss) per common share (basic and diluted) (0.47 ) (2.71 ) 0.24 (0.03 ) Common distributions declared (1) 0.43 0.43 0.43 0.56 (1) The fourth quarter of 2015 includes a non-cash distribution of $0.13 per share related to the distribution of RMR Inc. shares to our shareholders on December 14, 2015.

Organization (Details)

Organization (Details)	12 Months Ended
	Dec. 31, 2016ft²propertystatebuilding$ / sharesshares	Dec. 31, 2015$ / shares
Real Estate Properties [Line Items]
Rentable area of properties (in square feet) | ft²	830,185
Common shares of beneficial interest, par value (in dollars per share) | $ / shares	$ 0.01	$ 0.01
Discontinued operations
Real Estate Properties [Line Items]
Number of properties owned | property	1
Number of buildings | building	1
Continuing operations
Real Estate Properties [Line Items]
Number of properties owned | property	73
Number of buildings | building	95
Number of states in which owned properties located | state	31
Rentable area of properties (in square feet) | ft²	11,400,000
SIR
Real Estate Properties [Line Items]
SIR Common shares of beneficial interest acquired pursuant to stock purchase agreement | shares	24,918,421
Common shares of beneficial interest, par value (in dollars per share) | $ / shares	$ 0.01
Percentage of ownership interest	27.90%

Summary of Significant Accoun33

Summary of Significant Accounting Policies (Details) $ / shares in Units, $ in Thousands	Jun. 05, 2015USD ($)shares	Jun. 30, 2015USD ($)	Dec. 31, 2016USD ($)segment$ / sharesshares	Dec. 31, 2015USD ($)$ / shares	Dec. 31, 2014USD ($)
Real Estate Properties
Net decreases to rental income from amortization of capitalized above market and below market leases			$ 1,457	$ 1,155	$ 868
Amortization of the value of leases			29,003	28,624	27,713
Projected future amortization of net intangible lease assets and liabilities, excluding those classified as discontinued operations
Loss on impairment of Select Income REIT investment		$ 203,297	$ 0	203,297	0
Available-for-Sale Securities
Common shares owned in RMR Inc. | shares			1,214,225
Purchase price			$ 199,031
Deferred Financing Fees
Deferred financing fees, net			14,725	$ 6,026
Future amortization of deferred financing fees
2,017			2,892
2,018			2,896
2,019			1,639
2,020			779
2,021			640
Thereafter			$ 8,496
Common shares of beneficial interest, par value (in dollars per share) | $ / shares			$ 0.01	$ 0.01
Segment Reporting
Number of business segments | segment			2
Minimum | Buildings and improvements
Real Estate Properties
Estimated useful lives			7 years
Maximum | Buildings and improvements
Real Estate Properties
Estimated useful lives			40 years
Weighted Average
Real Estate Properties
Below market, acquired lease amortization period			6 years 7 months 28 days
Original value lease
Real Estate Properties
Amortization of the value of leases			$ 27,546	$ 27,467	26,844
Original value lease | Weighted Average
Real Estate Properties
Acquired lease amortization period			5 years 18 days
Above market lease | Weighted Average
Real Estate Properties
Acquired lease amortization period			4 years 5 months 5 days
Continuing operations
Real Estate Properties
Below market, capitalized value of leases			$ 20,603	25,553
Below market, accumulated amortization of capitalized lease values			9,977	12,818
Projected future amortization of net intangible lease assets and liabilities, excluding those classified as discontinued operations
2,017			33,578
2,018			28,828
2,019			19,853
2,020			10,478
2,021			7,959
Thereafter			13,526
Revenue Recognition
Increase in rental income to record revenue on straight line basis			2,691	3,978	$ 4,495
Straight line rent receivables (liabilities)			21,686	18,995
Deferred Leasing Costs
Deferred leasing costs, gross			28,039	20,300
Accumulated amortization of deferred leasing costs			6,960	6,001
Future amortization of deferred leasing costs, excluding those classified as discontinued operations
2,017			3,598
2,018			3,279
2,019			3,115
2,020			2,521
2,021			2,086
Thereafter			6,480
Continuing operations | Original value lease
Real Estate Properties
Capitalized value of leases			203,368	188,471
Accumulated amortization of capitalized lease values			95,028	86,610
Continuing operations | Above market lease
Real Estate Properties
Capitalized value of leases			39,261	37,875
Accumulated amortization of capitalized lease values			22,753	21,469
Unsecured revolving credit facility
Deferred Financing Fees
Deferred financing fees, gross			5,234	5,234
Accumulated amortization of deferred financing fees			2,617	1,385
RMR Inc.
Available-for-Sale Securities
Purchase price	$ 17,462
Initial other liabilities			20,667
Class A common stock | RMR Inc.
Available-for-Sale Securities
Shares acquired (in shares) | shares	1,541,201
Cost method investment	$ 39,833
RMR Inc
Available-for-Sale Securities
Recognized amortization of the liability			$ 1,087	$ 1,268

Weighted Average Common Share A

Weighted Average Common Share Amounts (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Earnings Per Share, Basic and Diluted [Abstract]
Weighted average common shares for basic earnings per share (in shares)	71,050	70,700	61,313
Effect of dilutive securities: unvested share awards (in shares)	21	0	86
Weighted average common shares for diluted earnings per share (in shares)	71,071	70,700	61,399

Recent Accounting Pronounceme35

Recent Accounting Pronouncements (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Increase (decrease) in debt issuance costs	$ 14,725	$ 6,026
Deferred gain on sale of real estate	$ 712
Assets | Unsecured term loan | Update 2015-03
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Increase (decrease) in debt issuance costs		(3,510)
Assets | Senior unsecured notes | Update 2015-03
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Increase (decrease) in debt issuance costs		(2,172)
Assets | Mortgage notes | Update 2015-03
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Increase (decrease) in debt issuance costs		(344)
Debt Liability | Unsecured term loan | Update 2015-03
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Increase (decrease) in debt issuance costs		3,510
Debt Liability | Senior unsecured notes | Update 2015-03
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Increase (decrease) in debt issuance costs		2,172
Debt Liability | Mortgage notes | Update 2015-03
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Increase (decrease) in debt issuance costs		$ 344

Real Estate Properties - Additi

Real Estate Properties - Additional Information (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2016USD ($)ft²leasetenantpropertybuilding	Dec. 31, 2015USD ($)
Real Estate Properties [Line Items]
Carry value of properties	$ 1,888,760	$ 1,696,132
Number of leases entered | lease	61
Rentable square feet (in sqft) | ft²	1,613,041
Square foot expansion (in sqft) | ft²	25,579
Weighted average lease term	8 years 7 months 6 days
Expenditures committed on leases	$ 38,489
Committed but unspent tenant related obligations estimated	26,459
Current expansion cost	15,355
Interest capitalized	$ 52
Number of government tenants | tenant	15
Tenant concentration
Real Estate Properties [Line Items]
Percentage termination right, 2017	1.80%
Percentage termination right, 2018	1.80%
Percentage termination right, 2019	7.30%
Percentage termination right, 2020	12.80%
Percentage termination right, 2021	1.30%
Percentage termination right, 2022	4.60%
Percentage termination right, 2023	2.80%
Percentage termination right, 2026	3.70%
Percentage termination right, 2027	2.20%
Government Tenants, All Other | Tenant concentration
Real Estate Properties [Line Items]
Concentration risk, percentage	6.60%
15 Government Tenants | Tenant concentration
Real Estate Properties [Line Items]
Concentration risk, percentage	18.80%
Continuing operations
Real Estate Properties [Line Items]
Number of properties owned | property	73
Number of buildings | building	95
Carry value of properties	$ 1,888,760
Discontinued operations
Real Estate Properties [Line Items]
Number of properties owned | property	1
Number of buildings | building	1
Real estate properties, net	$ 12,260

Real Estate Properties - Future

Real Estate Properties - Future Minimum Lease Payments (Details) $ in Thousands	Dec. 31, 2016USD ($)
Real Estate [Abstract]
2,017	$ 242,867
2,018	219,676
2,019	190,106
2,020	140,014
2,021	118,815
Thereafter	364,419
Total	$ 1,275,897

Real Estate Properties - Acquis

Real Estate Properties - Acquisition Activities (Details) $ in Thousands	Dec. 22, 2016USD ($)ft²propertybuilding	Dec. 20, 2016USD ($)ft²propertybuilding	Jul. 06, 2016USD ($)ft²parcel_of_land	Jan. 29, 2016USD ($)ft²propertybuilding	Jan. 31, 2017USD ($)ft²building	Aug. 31, 2016USD ($)	Dec. 31, 2016USD ($)ft²propertybuilding	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)	Feb. 28, 2017property
Real Estate Properties [Line Items]
Number of properties acquired | property							3
Rentable area of properties (in square feet) | ft²							830,185
Purchase price							$ 199,031
Acquisition related costs							1,191	$ 811	$ 1,344
Land							14,797
Buildings and Improvements							144,375
Other Assumed Assets							2,167
Acquired Leases							38,279
Acquired Lease Obligations							$ (587)
Sacramento, CA
Real Estate Properties [Line Items]
Number of properties acquired | property				1
Number of buildings acquired | building				1
Rentable area of properties (in square feet) | ft²				337,811
Purchase price				$ 79,235
Land				4,688
Buildings and Improvements				61,722
Other Assumed Assets				2,167
Acquired Leases				11,245
Acquired Lease Obligations				$ (587)
Atlanta, GA
Real Estate Properties [Line Items]
Rentable area of properties (in square feet) | ft²			0
Purchase price			$ 1,670
Land			1,670
Buildings and Improvements			0
Other Assumed Assets			0
Acquired Leases			0
Acquired Lease Obligations			$ 0
Rancho Cordova, CA
Real Estate Properties [Line Items]
Number of properties acquired | property		1
Number of buildings acquired | building		1
Rentable area of properties (in square feet) | ft²		82,896
Purchase price		$ 13,943
Land		1,465
Buildings and Improvements		8,537
Other Assumed Assets		0
Acquired Leases		3,941
Acquired Lease Obligations		$ 0
Chantilly, VA
Real Estate Properties [Line Items]
Number of properties acquired | property	1
Number of buildings acquired | building	3
Rentable area of properties (in square feet) | ft²	409,478
Purchase price	$ 104,183
Land	6,974
Buildings and Improvements	74,116
Other Assumed Assets	0
Acquired Leases	23,093
Acquired Lease Obligations	$ 0
Land parcel | Atlanta, GA
Real Estate Properties [Line Items]
Number of properties acquired | parcel_of_land			1
Purchase price			$ 1,623
Acquisition related costs			$ 47
Transferable Development Rights | Washington, D.C.
Real Estate Properties [Line Items]
Purchase price						$ 2,030
Office Building
Real Estate Properties [Line Items]
Number of buildings acquired | building							5
Office Building | Manassas, VA
Real Estate Properties [Line Items]
Number of properties acquired | property							1
Subsequent Event | Office Building | Manassas, VA
Real Estate Properties [Line Items]
Number of buildings acquired | building					1
Rentable area of properties (in square feet) | ft²					69,374
Purchase price					$ 13,200
Subsequent Event | Office Building | Salem, OR
Real Estate Properties [Line Items]
Number of properties acquired | property										1

Real Estate Properties - Dispos

Real Estate Properties - Disposition Activities (Details) $ in Thousands	1 Months Ended	9 Months Ended	12 Months Ended
	Jul. 31, 2016USD ($)ft²propertybuilding	Sep. 30, 2016	Dec. 31, 2016USD ($)ft²	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)propertybuilding	Mar. 31, 2016ft²propertybuilding	Feb. 28, 2015property
Real Estate Properties [Line Items]
Rentable area of properties (in square feet) | ft²			830,185
Gain on sale of real estate			$ 79	$ 0	$ 0
Net book value			1,591,956	$ 1,440,253
Deferred gain on sale of real estate			712
Office Building | Disposal Group, Held-for-sale, Not Discontinued Operations | Riverdale, MD | One building
Real Estate Properties [Line Items]
Number of properties | property							1
Office Building | Disposal Group, Held-for-sale, Not Discontinued Operations | Savannah, GA | One building
Real Estate Properties [Line Items]
Number of properties | property	1
Number of buildings | building	1
Rentable area of properties (in square feet) | ft²	35,228
Net book value	$ 2,986
Aggregate sale price of properties sold, excluding closing costs	4,000
Mortgage financing to the buyer	$ 3,600
Office Building | Discontinued Operations, Held-for-sale | One building
Real Estate Properties [Line Items]
Number of properties | property					2
Number of buildings | building					2
Office Building | Discontinued Operations, Held-for-sale | Falls Church, VA | One building
Real Estate Properties [Line Items]
Number of properties | property						1
Number of buildings | building						1
Rentable area of properties (in square feet) | ft²						164,746
Net book value			12,282
Aggregate sale price of properties sold, excluding closing costs			13,148
LIBOR | Disposal Group, By Sale, Not Discontinued Operations | Savannah, GA
Real Estate Properties [Line Items]
Interest rate premium (as a percent)		4.00%
Minimum | LIBOR | Disposal Group, By Sale, Not Discontinued Operations | Savannah, GA
Real Estate Properties [Line Items]
Interest rate premium (as a percent)		5.00%
Other Assets
Real Estate Properties [Line Items]
Deferred gain on sale of real estate			712
Real Estate Loan | Other Assets
Real Estate Properties [Line Items]
Mortgage note receivable			$ 3,600

Real Estate Properties - Balanc

Real Estate Properties - Balance Sheet Information for Disposal of Property (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Assets of property held for sale	$ 0	$ 3,098
Assets of discontinued operations	12,541	12,468
Liabilities of discontinued operations	45	54
Liabilities of property held for sale	0	43
Disposal Group, Held-for-sale, Not Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Real estate properties, net		3,071
Rents receivable		1
Other assets		26
Assets of property held for sale		3,098
Other liabilities		43
Liabilities of property held for sale		43
Discontinued operations | Discontinued Operations, Held-for-sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Real estate properties, net	12,260	12,260
Other assets	281	208
Assets of discontinued operations	12,541	12,468
Other liabilities	45	54
Liabilities of discontinued operations	$ 45	$ 54

Real Estate Properties - Income

Real Estate Properties - Income Statement Information for Disposal of Property (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income (loss) from discontinued operations	$ (589)	$ (525)	$ 3,498
Discontinued operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Rental income	68	114	1,673
Real estate taxes	(97)	(92)	(427)
Utility expenses	(146)	(161)	(226)
Other operating expenses	(300)	(272)	(459)
General and administrative	(114)	(114)	(181)
Increase in carrying value of asset held for sale	0	0	2,344
Net gain on sale of properties	0	0	774
Income (loss) from discontinued operations	$ (589)	$ (525)	$ 3,498

Business and Property Managem42

Business and Property Management Agreements with RMR LLC (Details) - RMR LLC $ in Thousands	Jun. 05, 2015	May 31, 2015shares	Dec. 31, 2016USD ($)employeeagreement	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)shares
Related Party Transaction [Line Items]
Number of employees | employee			0
Number of agreements with RMR LLC to provide management services | agreement			2
Management fees as percentage of gross collected rents			3.00%
Construction supervision fees as percentage of construction costs			5.00%
Net business management fees			$ 10,222	$ 9,934	$ 10,226
Recognized amortization of the liability			603	372
Shares issued (in shares) | shares		19,339			42,442
Net property management and construction supervision fees			8,949	7,977	$ 8,203
Reimbursement amounts			12,276	9,641	7,982
Internal audit costs			$ 235	$ 252	$ 286
Transition Services
Related Party Transaction [Line Items]
Duration of transition services			120 days
Amended And Restate Business Management Agreement
Related Party Transaction [Line Items]
Percentage applied on average historical cost of real estate investment properties acquired			0.50%
Base management fee payable as percentage of average historical cost of real estate investments			0.70%
Percentage of average closing stock price on stock exchange			0.70%
Management fee payable as percentage of average market capitalization exceeding specified amount			0.50%
Percentage for limitation and adjustments of incentive management fee payable			12.00%
Measurement period for incentive management fee			3 years
Measurement period for calculating management fee				2 years	1 year
Percentage of base business management fee payable in common shares			1.50%
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
Amended And Restate Business Management Agreement | Up C Transaction
Related Party Transaction [Line Items]
Written notice for convenience	60 days
Written notice for performance	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
Related Party Transaction [Line Items]
Threshold amount of average market capitalization			$ 250,000
Minimum | Amended And Restate Business Management Agreement | Up C Transaction
Related Party Transaction [Line Items]
Termination fee term	19 years
Maximum | Amended And Restate Business Management Agreement
Related Party Transaction [Line Items]
Threshold amount of real estate investments			250,000
Base management fee payable average market capitalization			$ 250,000
Maximum | Amended And Restate Business Management Agreement | Up C Transaction
Related Party Transaction [Line Items]
Termination fee term	20 years

Related Party Transactions - Up

Related Party Transactions - Up-C Transaction (Details) $ in Thousands	Dec. 14, 2015shares	Jun. 05, 2015USD ($)shares	Dec. 31, 2015USD ($)shares	Sep. 30, 2016USD ($)	Dec. 31, 2016USD ($)agreementcompanyshares	Dec. 31, 2015USD ($)shares	Dec. 31, 2014USD ($)shares
Related Party Transaction [Line Items]
Common shares owned in RMR Inc.					1,214,225
Common shares held			71,126,308		71,177,906	71,126,308
Up C Transaction | Class A common shares
Related Party Transaction [Line Items]
Common shares owned in RMR Inc.					1,214,225
Up C Transaction | SIR | Class A common shares
Related Party Transaction [Line Items]
Common shares held					441,056
Up C Transaction | RMR Inc | Class A common shares
Related Party Transaction [Line Items]
Non-cash loss related to distribution of shares | $			$ 12,368
Up C Transaction | RMR Inc | Class A member units
Related Party Transaction [Line Items]
Shares issued in connection with acquisition	768,032
RMR LLC
Related Party Transaction [Line Items]
Number of agreements with RMR LLC to provide management services | agreement					2
Rental income earned | $				$ 366		$ 341	$ 61
RMR Inc | Up C Transaction
Related Party Transaction [Line Items]
Number of other companies to whom management services were provided by related party | company					3
Aggregate consideration paid | $		$ 3,917
RMR Inc | Up C Transaction | Common Shares
Related Party Transaction [Line Items]
Shares issued in connection with acquisition		700,000
RMR Inc | Up C Transaction | RMR Inc | Common Shares
Related Party Transaction [Line Items]
Shares issued in connection with acquisition		1,541,201
Managing Trustees Barry And Adam Portnoy Member | Up C Transaction | ABP Trust formerly known as RMR trust
Related Party Transaction [Line Items]
Number of shares under lock up and registration agreement					700,000
Period over which shares remain under lock up and registration agreement					10 years
Direct and indirect economic interest in RMR LLC as a percent					51.90%
Voting power of outstanding capital stock of RMR Inc					91.50%
2009 Award Plan
Related Party Transaction [Line Items]
Number of shares granted to each trustee under the award plan					65,900	65,600	63,650
Common Shares | 2009 Award Plan | Officers and Other Employees
Related Party Transaction [Line Items]
Number of shares granted to each trustee under the award plan					53,400	53,100	51,150
Aggregate market value of shares awarded | $					$ 1,183	$ 841	$ 1,191
Tranche One | Common Shares | 2009 Award Plan | Officers and Other Employees
Related Party Transaction [Line Items]
Vesting percentage					20.00%
Tranche Two | Common Shares | 2009 Award Plan | Officers and Other Employees
Related Party Transaction [Line Items]
Vesting percentage					20.00%
Tranche Three | Common Shares | 2009 Award Plan | Officers and Other Employees
Related Party Transaction [Line Items]
Vesting percentage					20.00%
Tranche Four | Common Shares | 2009 Award Plan | Officers and Other Employees
Related Party Transaction [Line Items]
Vesting percentage					20.00%
Tranche Five | Common Shares | 2009 Award Plan | Officers and Other Employees
Related Party Transaction [Line Items]
Vesting percentage					20.00%

Related Party Transactions - RE

Related Party Transactions - REITs, for which RMR LLC provides Management Services (Details) $ / shares in Units, $ in Thousands	Mar. 05, 2015shares	Mar. 04, 2015USD ($)shares	Jul. 09, 2014USD ($)$ / sharesshares	Jun. 30, 2017USD ($)	Jun. 30, 2016USD ($)	Jun. 30, 2015USD ($)	Dec. 31, 2014USD ($)	Dec. 31, 2016USD ($)companyshares	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)
Related Party Transaction [Line Items]
Recognized income (loss) related to investment								$ 35,518	$ 18,640	$ 10,963
EQC
Related Party Transaction [Line Items]
Percentage of ownership interest								100.00%
AIC | RMR LLC
Related Party Transaction [Line Items]
Service fee percentage								3.00%
SIR
Related Party Transaction [Line Items]
Percentage of ownership interest								27.90%
Recognized income (loss) related to investment							$ 17,113	$ 35,381	21,882
SIR | EQC
Related Party Transaction [Line Items]
SIR Common shares of beneficial interest acquired pursuant to stock purchase agreement | shares			21,500,000
Cash purchase price			$ 677,500
Cash purchase price excluding accrued dividends (in dollars per share) | $ / shares			$ 31.51
Accrued dividends			$ 11,300
Accrued dividends (in dollars per share) | $ / shares			$ 0.53
Cash purchase price including accrued dividends			$ 688,800
RMR LLC | SIR | RMR LLC | EQC
Related Party Transaction [Line Items]
SIR Common shares of beneficial interest acquired pursuant to stock purchase agreement | shares			500,000
SIR
Related Party Transaction [Line Items]
Percentage of ownership interest								27.90%
SIR Common shares of beneficial interest acquired pursuant to stock purchase agreement | shares								24,918,421
SIR | Lakewood Capital Partners LP
Related Party Transaction [Line Items]
Percentage of ownership interest		3.90%
Cash purchase price		$ 95,203
Number of shares purchased under shareholder agreement | shares		3,418,421
SIR | Adam Portnoy | Lakewood Capital Partners LP
Related Party Transaction [Line Items]
Number of shares purchased under shareholder agreement | shares	2,429	87,606
SIR | Barry Portnoy | Lakewood Capital Partners LP
Related Party Transaction [Line Items]
Number of shares purchased under shareholder agreement | shares		107,606
AIC
Related Party Transaction [Line Items]
Number of entities to whom RMR provides management services | company								4
Coverage of purchased property insurance					$ 1,277	$ 526		$ 106	316	529
Amount invested in equity investee							$ 6,946	7,235	6,946	6,946
Recognized income (loss) related to investment								137	20	87
Unrealized gains (losses) on securities								$ 152	$ (20)	$ 2
Forecast | AIC
Related Party Transaction [Line Items]
Coverage of purchased property insurance				$ 1,032

Concentration (Details)

Concentration (Details)	12 Months Ended
	Dec. 31, 2016propertystatebuildingstate_governmentgovernment_tenant	Dec. 31, 2015	Dec. 31, 2014
Concentration
Number of state governments | state_government	13
Number of other governments | government_tenant	3
Annualized rental income, excluding properties classified as discontinued operations | California
Concentration
Annualized Rental income percent	14.40%
Annualized rental income, excluding properties classified as discontinued operations | Virginia
Concentration
Annualized Rental income percent	14.30%
Annualized rental income, excluding properties classified as discontinued operations | District of Columbia
Concentration
Annualized Rental income percent	9.70%
Annualized rental income, excluding properties classified as discontinued operations | Georgia
Concentration
Annualized Rental income percent	8.70%
Annualized rental income, excluding properties classified as discontinued operations | New York
Concentration
Annualized Rental income percent	7.70%
Annualized rental income, excluding properties classified as discontinued operations | Maryland
Concentration
Annualized Rental income percent	7.20%
Annualized rental income, excluding properties classified as discontinued operations | Massachusetts
Concentration
Annualized Rental income percent	5.00%
Annualized rental income, excluding properties classified as discontinued operations | Tenant concentration | U S Government, State Governments, and Other Governments
Concentration
Concentration risk, percentage	87.90%	92.80%	93.00%
Annualized rental income, excluding properties classified as discontinued operations | Tenant concentration | U.S. Government
Concentration
Concentration risk, percentage	60.60%	67.00%	69.00%
Continuing operations
Concentration
Number of properties owned | property	73
Number of buildings | building	95
Number of states in which acquired properties located | state	31
Discontinued operations
Concentration
Number of properties owned | property	1
Number of buildings | building	1

Indebtedness - Additional Infor

Indebtedness - Additional Information (Details) - USD ($)	1 Months Ended		9 Months Ended	12 Months Ended
	Jun. 30, 2016	Dec. 31, 2014	Sep. 30, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Feb. 21, 2017	May 31, 2016
Debt Instrument [Line Items]
Unsecured term loans, net				$ 547,171,000	$ 546,490,000
Aggregate principal amount of properties collateralized				27,508,000
Maximum potential borrowing capacity				2,500,000,000
Unsecured term loan, due in 2020
Debt Instrument [Line Items]
Face amount				$ 300,000,000
Interest rate (as a percent)				2.20%
The weighted average annual interest rate (as a percent)		1.90%		1.90%	1.60%
Basis spread on variable rate				1.40%
Unsecured term loan, due in 2022
Debt Instrument [Line Items]
Face amount				$ 250,000,000
Principal repayment is due until maturity			0.00%
Interest rate (as a percent)				2.60%
The weighted average annual interest rate (as a percent)		2.30%		2.30%	2.00%
Basis spread on variable rate				1.80%
5.875% Senior unsecured note due In 2046
Debt Instrument [Line Items]
Face amount								$ 300,000,000
Interest rate (as a percent)								5.875%
Underwriter option exercise amount	$ 10,000,000
Net proceeds from offering	$ 299,691,000
3.75% Senior unsecured note due In 2019
Debt Instrument [Line Items]
Face amount				$ 350,000,000
Interest rate (as a percent)				3.75%
Unsecured revolving credit facility
Debt Instrument [Line Items]
Unsecured term loans, net				$ 160,000,000
Maximum borrowing capacity on revolving credit facility				$ 750,000,000
Option to extend the maturity date subject to certain conditions and the payment of a fee				1 year
Interest rate (as a percent)				2.00%
The weighted average annual interest rate (as a percent)				1.70%	1.50%	1.70%
Basis spread on variable rate				1.25%
Commitment fee percentage				0.25%
Long-term debt
Debt Instrument [Line Items]
Face amount				$ 550,000,000
Senior unsecured notes
Debt Instrument [Line Items]
Face amount				$ 660,000,000
Subsequent Event | Unsecured revolving credit facility
Debt Instrument [Line Items]
Unsecured term loans, net							$ 170,000,000

Indebtedness - Repayment of Deb

Indebtedness - Repayment of Debt (Details) $ in Thousands	1 Months Ended		12 Months Ended
	Mar. 31, 2016USD ($)propertybuilding	Feb. 29, 2016USD ($)propertybuilding	Dec. 31, 2016USD ($)propertybuildingloan	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)
Debt Instrument [Line Items]
Number of buildings secured by mortgage notes | building			3
Number of properties secured by mortgage notes | property			3
Gain (loss) on early extinguishment of debt			$ 104	$ 34	$ (1,307)
Aggregate net book value of secured properties			$ 52,383
Number of assumed secured mortgage loans | loan			3
Aggregate principal amount of properties collateralized			$ 27,508
6.21% Mortgage notes due in 2016
Debt Instrument [Line Items]
Repayment of debt		$ 23,473
Interest rate (as a percent)		6.21%	6.21%
Number of buildings secured by mortgage notes | building		1
Number of properties secured by mortgage notes | property		1
Gain (loss) on early extinguishment of debt			$ (21)
5.55% Mortgage notes due in 2016
Debt Instrument [Line Items]
Repayment of debt	$ 83,000
Interest rate (as a percent)	5.55%		5.55%
Number of buildings secured by mortgage notes | building	2
Number of properties secured by mortgage notes | property	1
Gain (loss) on early extinguishment of debt			$ 125

Indebtedness - Future Principal

Indebtedness - Future Principal Payments (Details) $ in Thousands	Dec. 31, 2016USD ($)
Debt Disclosure [Abstract]
2,017	$ 1,549
2,018	1,671
2,019	519,439
2,020	301,619
2,021	13,230
Thereafter	560,000
Total	1,397,508
Unamortized premiums, discounts and certain issuance costs	15,656
Total debt outstanding	$ 1,381,852

Fair Value of Assets and Liab49

Fair Value of Assets and Liabilities - Asset Measured at Fair Value (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Fair Value of Assets and Liabilities
Common shares owned in RMR Inc.	1,214,225
Historical cost	$ 26,888
Unrealized gain on investment in available for sale securities	30,465	$ (9,391)
Recurring
Fair Value of Assets and Liabilities
Investment in RMR Inc.	47,962
Recurring | Level 1 inputs
Fair Value of Assets and Liabilities
Investment in RMR Inc.	47,962
Discontinued Operations, Held-for-sale | Nonrecurring
Fair Value of Assets and Liabilities
Property held for sale and classified as discontinued operations	12,260
Discontinued Operations, Held-for-sale | Nonrecurring | Level 3 inputs
Fair Value of Assets and Liabilities
Property held for sale and classified as discontinued operations	12,260
Cumulative Other Comprehensive Income (Loss)
Fair Value of Assets and Liabilities
Unrealized gain on investment in available for sale securities	$ 21,074

Fair Value of Assets and Liab50

Fair Value of Assets and Liabilities - Financial Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Mar. 31, 2016	Feb. 29, 2016	Dec. 31, 2015
Fair Value of Financial Instruments
Senior Notes	$ 646,844			$ 345,809
Mortgage notes payable	$ 27,837			136,299
3.75% Senior unsecured note due In 2019
Fair Value of Financial Instruments
Interest rate (as a percent)	3.75%
5.875% Senior unsecured note due In 2046
Fair Value of Financial Instruments
Interest rate (as a percent)	5.875%
6.21% Mortgage notes due in 2016
Fair Value of Financial Instruments
Interest rate (as a percent)	6.21%		6.21%
5.55% Mortgage notes due in 2016
Fair Value of Financial Instruments
Interest rate (as a percent)	5.55%	5.55%
5.88% Mortgage notes due in 2021
Fair Value of Financial Instruments
Interest rate (as a percent)	5.88%
7.00% Mortgage notes due in 2019
Fair Value of Financial Instruments
Interest rate (as a percent)	7.00%
8.15% Mortgage notes due in 2021
Fair Value of Financial Instruments
Interest rate (as a percent)	8.15%
Carrying Amount
Fair Value of Financial Instruments
Mortgage notes payable	$ 674,681			482,108
Carrying Amount | 3.75% Senior unsecured note due In 2019
Fair Value of Financial Instruments
Senior Notes	346,952			345,809
Carrying Amount | 5.875% Senior unsecured note due In 2046
Fair Value of Financial Instruments
Senior Notes	299,892			0
Carrying Amount | 6.21% Mortgage notes due in 2016
Fair Value of Financial Instruments
Mortgage notes payable	0			23,476
Carrying Amount | 5.55% Mortgage notes due in 2016
Fair Value of Financial Instruments
Mortgage notes payable	0			83,375
Carrying Amount | 5.88% Mortgage notes due in 2021
Fair Value of Financial Instruments
Mortgage notes payable	13,841			14,045
Carrying Amount | 7.00% Mortgage notes due in 2019
Fair Value of Financial Instruments
Mortgage notes payable	8,778			9,145
Carrying Amount | 8.15% Mortgage notes due in 2021
Fair Value of Financial Instruments
Mortgage notes payable	5,218			6,258
Fair Value
Fair Value of Financial Instruments
Mortgage notes payable	675,601			490,221
Fair Value | 3.75% Senior unsecured note due In 2019
Fair Value of Financial Instruments
Senior Notes	354,078			351,692
Fair Value | 5.875% Senior unsecured note due In 2046
Fair Value of Financial Instruments
Senior Notes	292,268			0
Fair Value | 6.21% Mortgage notes due in 2016
Fair Value of Financial Instruments
Mortgage notes payable	0			24,038
Fair Value | 5.55% Mortgage notes due in 2016
Fair Value of Financial Instruments
Mortgage notes payable	0			83,457
Fair Value | 5.88% Mortgage notes due in 2021
Fair Value of Financial Instruments
Mortgage notes payable	14,492			14,678
Fair Value | 7.00% Mortgage notes due in 2019
Fair Value of Financial Instruments
Mortgage notes payable	9,188			9,645
Fair Value | 8.15% Mortgage notes due in 2021
Fair Value of Financial Instruments
Mortgage notes payable	$ 5,575			$ 6,711

Shareholders' Equity (Details)

Shareholders' Equity (Details) $ / shares in Units, $ in Thousands	Jan. 13, 2017USD ($)$ / shares	Dec. 14, 2015$ / sharesshares	Sep. 30, 2016$ / sharesshares	Sep. 30, 2015$ / sharesshares	Dec. 31, 2016USD ($)$ / sharesshares	Sep. 30, 2016$ / shares	Jun. 30, 2016$ / shares	Mar. 31, 2016$ / shares	Dec. 31, 2015$ / sharesshares	Sep. 30, 2015$ / shares	Jun. 30, 2015$ / shares	Mar. 31, 2015$ / shares	Dec. 31, 2016USD ($)installment$ / sharesshares	Dec. 31, 2015USD ($)$ / sharesshares	Dec. 31, 2014USD ($)$ / sharesshares	Dec. 31, 2013shares
Distributions
Common distributions declared (in dollars per share) | $ / shares					$ 0.43	$ 0.43	$ 0.43	$ 0.43	$ 0.56	$ 0.43	$ 0.43	$ 0.43	$ 1.72	$ 1.72	$ 1.72
Ratio of shares distributed per share		0.0108
Non-cash distribution, per share, related to distribution of shares (in dollars per share) | $ / shares		$ 0.1284							$ 0.13
Characterization of distributions paid or accrued as a percentage of ordinary income													62.74%	47.44%	55.12%
Characterization of distributions paid or accrued as a percentage of return of capital													36.21%	37.12%	41.94%
Characterization of distributions paid or accrued as a percentage of qualified dividend													1.05%	0.93%
Characterization of distributions paid or accrued as a percentage of capital gain														12.90%
Characterization of distributions paid or accrued as a percentage of Internal Revenue Code section 1250 gain														1.61%	2.94%
Distribution payable to common shareholders | $													$ 122,366	$ 130,792	$ 100,856
Common Shares
Share Issuances
Share repurchased (in shares)													14,302	11,741
2009 Award Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares granted to each trustee under the award plan													65,900	65,600	63,650
Number of installments | installment													5
Vesting schedule of unvested shares
Unvested shares					98,970				96,725				98,970	96,725	90,338	85,451
2017 (in shares)					37,880								37,880
2018 (in shares)					29,810								29,810
2019 (in shares)					20,600								20,600
2020 (in shares)					10,680								10,680
Share Awards, additional disclosures
Estimated future compensation expense for the unvested shares | $					$ 1,887								$ 1,887
Closing share price of the entity's common shares (in dollars per share) | $ / shares					$ 19.07								$ 19.07
Weighted average period of recognition of compensation expenses (in years)													21 months
Compensation expense | $													$ 1,371	$ 932	$ 1,165
Shares available for issuance under the Award Plan					1,554,105								1,554,105
2009 Award Plan | Common Shares
Share Issuances
Share repurchased (in shares)			14,302	10,721
Price per share repurchased (in dollars per share) | $ / shares			$ 23.54	$ 16.12
2009 Award Plan | Trustees | Common Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares granted to each trustee under the award plan													2,500	2,500	2,500
Aggregate market value of shares awarded | $													$ 244	$ 247	$ 318
Market value of common shares awarded to each trustee (in dollars) | $													$ 49	$ 49	$ 64
Subsequent Event
Distributions
Distribution payable to common shareholders (in dollars per share) | $ / shares	$ 0.43
Distribution payable to common shareholders | $	$ 30,607
Class A member units | RMR Inc | Up C Transaction
Distributions
Shares distributed (in shares)		768,032

Shareholders' Equity - Unvested

Shareholders' Equity - Unvested Shares Activity (Details) - 2009 Award Plan - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Number of Shares
Unvested shares at the beginning of the period	96,725	90,338	85,451
Shares granted (in shares)	65,900	65,600	63,650
Shared forfeited or repurchased (in shares)		(1,020)
Shares Vested (in shares)	(63,655)	(58,193)	(58,763)
Unvested shares at the end of the period	98,970	96,725	90,338
Weighted Average Grant Date Fair Value
Unvested shares at the beginning of the period (in dollars per share)	$ 20.11	$ 23.40	$ 23.71
Granted (in dollars per share)	21.66	16.59	23.70
Shared forfeited or repurchased (in dollars per share)		23.41
Vested (in dollars per share)	20.97	21.20	24.17
Unvested shares at the end of the period (in dollars per share)	$ 20.59	$ 20.11	$ 23.40

Shareholders' Equity - Cumulati

Shareholders' Equity - Cumulative Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ (14,867)	$ 37	$ 49
Other comprehensive income (loss) before reclassifications	41,719	(14,983)	37
Amounts reclassified from cumulative other comprehensive loss to net income (loss)	105	79	(49)
Net current period other comprehensive income (loss)	41,824	(14,904)	(12)
Ending balance	26,957	(14,867)	37
Unrealized Gain (Loss) on Investment in Available for Sale Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(9,391)	0	0
Other comprehensive income (loss) before reclassifications	30,465	(9,391)	0
Amounts reclassified from cumulative other comprehensive loss to net income (loss)	0	0	0
Net current period other comprehensive income (loss)	30,465	(9,391)	0
Ending balance	21,074	(9,391)	0
Equity in Unrealized Gains (Losses) of Investees
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(5,476)	37	49
Other comprehensive income (loss) before reclassifications	11,254	(5,592)	37
Amounts reclassified from cumulative other comprehensive loss to net income (loss)	105	79	(49)
Net current period other comprehensive income (loss)	11,359	(5,513)	(12)
Ending balance	$ 5,883	$ (5,476)	$ 37

Equity Investment in Select I54

Equity Investment in Select Income REIT (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended	12 Months Ended
	Jun. 30, 2015	Dec. 31, 2014	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Schedule of Equity Method Investments [Line Items]
Equity in earnings of investees			$ 35,518	$ 18,640	$ 10,963
Unrealized gain (loss) from investees			11,359	(5,513)	(12)
Investment at carrying value			487,708	491,369
Gain (loss) on issuance of shares by Select Income REIT			86	(42,145)	(53)
Loss on impairment of Select Income REIT investment	$ 203,297		0	203,297	0
Distributions of earnings from Select Income REIT			$ 32,425	$ 21,882	17,046
Common shares held			71,177,906	71,126,308
Distribution of RMR common stock received from Select Income REIT			$ 0	$ 5,244	0
SIR
Schedule of Equity Method Investments [Line Items]
Equity investments, common shares owned			24,918,421
Percentage of outstanding shares owned			27.90%
Equity in earnings of investees		$ 17,113	$ 35,381	21,882
Unrealized gain (loss) from investees		$ (14)	11,207	(5,493)
Investment at carrying value			487,708
Equity Investments, market value			627,944
The amount of investment in exceed the underlying equity of the investee			166,272
Amortization of the difference between carrying value and share of underlying equity				4,742	6,237
Difference in basis accreted over remaining period	$ (90,186)
Accretion of equity in earnings			2,956	1,480
Distributions of earnings from Select Income REIT			50,335	$ 47,030	20,640
SIR | Class A common shares
Schedule of Equity Method Investments [Line Items]
Common shares held				441,056
Distribution of RMR common stock received from Select Income REIT				$ 5,244
SIR | SIR
Schedule of Equity Method Investments [Line Items]
Equity in earnings of investees			$ 137	$ 20	$ 87
Issuance of shares, net (in shares)		67,947	65,900	29,414,279
Gain (loss) on issuance of shares by Select Income REIT		$ (53)	$ 86	$ (42,145)

Equity Investment in Select I55

Equity Investment in Select Income REIT - Balance Sheet Information (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Schedule of Equity Method Investments [Line Items]
Real Estate Investment Property, Net	$ 1,591,956	$ 1,440,253
Acquired real estate leases, net	124,848	118,267
Cash and cash equivalents	29,941	8,785	$ 13,791	$ 7,663
Rents receivable, net	48,458	45,269
Other assets, net	68,005	33,680
Total assets	2,385,066	2,168,510	2,419,908
Unsecured revolving credit facility	160,000	117,000
Unsecured term loan, net	547,171	546,490
Senior unsecured notes, net	646,844	345,809
Mortgage notes payable, net	27,837	136,299
Assumed real estate lease obligations, net	10,626	12,735
Other Liabilities	54,019	50,543
Shareholders' equity	935,004	956,651	$ 1,297,449	$ 989,675
Total liabilities and shareholders’ equity	2,385,066	2,168,510
SIR | SIR
Schedule of Equity Method Investments [Line Items]
Real Estate Investment Property, Net	3,899,792	3,954,889
Acquired real estate leases, net	506,298	566,195
Cash and cash equivalents	22,127	17,876
Rents receivable, net	124,089	99,307
Other assets, net	87,376	46,078
Total assets	4,639,682	4,684,345
Unsecured revolving credit facility	327,000	303,000
Unsecured term loan, net	348,373	347,876
Senior unsecured notes, net	1,430,300	1,426,025
Mortgage notes payable, net	245,643	286,706
Assumed real estate lease obligations, net	77,622	86,495
Other Liabilities	136,782	137,283
Shareholders' equity	2,073,962	2,096,960
Total liabilities and shareholders’ equity	$ 4,639,682	$ 4,684,345

Equity Investment in Select I56

Equity Investment in Select Income REIT - Income Statement Information (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								6 Months Ended	12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Schedule of Equity Method Investments [Line Items]
Total revenues	$ 66,030	$ 64,478	$ 64,061	$ 63,611	$ 61,685	$ 62,092	$ 62,113	$ 62,659		$ 258,180	$ 248,549	$ 251,031
Real estate taxes										30,703	29,906	28,389
Other operating expenses										54,290	50,425	45,982
Depreciation and amortization										73,153	68,696	66,593
Acquisition related costs										1,191	811	1,344
General and administrative										14,897	14,826	15,809
Total expenses										191,503	182,580	179,502
Operating income										66,677	65,969	71,529
Dividend income										971	811	0
Interest expense										(45,060)	(37,008)	(28,048)
Gain (loss) on early extinguishment of debt										104	34	(1,307)
Loss on distribution of The RMR Group Inc. common stock										0	(12,368)	0
Income (loss) from continuing operations before income taxes and equity in earnings of investees										22,936	(227,990)	42,190
Income tax expense										(101)	(86)	(117)
Equity in earnings of an investee										$ 35,518	$ 18,640	$ 10,963
Weighted average common shares outstanding (basic) (in shares)										71,050	70,700	61,313
Weighted average common shares outstanding (diluted) (in shares)										71,071	70,700	61,399
Net income attributed to SIR per common share (basic and diluted) (in dollars per share)	$ 0.17	$ 0.16	$ 0.24	$ 0.24	$ (0.03)	$ 0.24	$ (2.71)	$ (0.47)		$ 0.81	$ (2.97)	$ 0.92
SIR
Schedule of Equity Method Investments [Line Items]
Equity in earnings of an investee									$ 17,113	$ 35,381	$ 21,882
SIR | SIR
Schedule of Equity Method Investments [Line Items]
Rental income										387,015	364,139	$ 189,743
Tenant reimbursements and other income										74,992	64,226	32,937
Total revenues										462,007	428,365	222,680
Real estate taxes										42,879	37,460	22,202
Other operating expenses										52,957	41,953	18,597
Depreciation and amortization										133,762	122,906	41,054
Acquisition related costs										306	21,987	7,348
General and administrative										28,602	25,859	14,881
Loss on asset impairment										5,484	0	0
Total expenses										263,990	250,165	104,082
Operating income										198,017	178,200	118,598
Dividend income										1,268	1,666	0
Interest expense										(82,620)	(73,885)	(12,974)
Gain (loss) on early extinguishment of debt										0	(6,845)	243
Loss on distribution of The RMR Group Inc. common stock										0	(23,717)	0
Income (loss) from continuing operations before income taxes and equity in earnings of investees										116,665	75,419	105,867
Income tax expense										(448)	(515)	(175)
Equity in earnings of an investee										137	20	87
Net income before gain on sale of property										116,354	74,924	105,779
Gain on sale of property										0	0	116
Net income										116,354	74,924	105,895
Net income allocated to noncontrolling interest										(33)	(176)	0
Net income attributed to SIR										$ 116,321	$ 74,748	$ 105,895
Weighted average common shares outstanding (basic) (in shares)										89,304	86,699	55,964
Weighted average common shares outstanding (diluted) (in shares)										89,324	86,708	56,035
Net income attributed to SIR per common share (basic and diluted) (in dollars per share)										$ 1.30	$ 0.86	$ 1.89

Segment Information (Details)

Segment Information (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016USD ($)	Sep. 30, 2016USD ($)	Jun. 30, 2016USD ($)	Mar. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Sep. 30, 2015USD ($)	Jun. 30, 2015USD ($)	Mar. 31, 2015USD ($)	Dec. 31, 2016USD ($)segment	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)
Segment Reporting Information [Line Items]
Number of segments | segment									2
Rental income	$ 66,030	$ 64,478	$ 64,061	$ 63,611	$ 61,685	$ 62,092	$ 62,113	$ 62,659	$ 258,180	$ 248,549	$ 251,031
Expenses:
Real estate taxes									30,703	29,906	28,389
Utility expenses									17,269	17,916	19,369
Other operating expenses									54,290	50,425	45,982
Depreciation and amortization									73,153	68,696	66,593
Loss on impairment of real estate									0	0	2,016
Acquisition related costs									1,191	811	1,344
General and administrative									14,897	14,826	15,809
Total expenses									191,503	182,580	179,502
Operating income (loss)									66,677	65,969	71,529
Dividend income									971	811	0
Interest income									158	14	69
Interest expense									(45,060)	(37,008)	(28,048)
Gain (loss) on early extinguishment of debt									104	34	(1,307)
Loss on distribution to common shareholders of The RMR Group Inc. common stock									0	(12,368)	0
Net gain (loss) on issuance of shares by Select Income REIT									86	(42,145)	(53)
Loss on impairment of Select Income REIT investment							(203,297)		0	(203,297)	0
Income (loss) from continuing operations before income taxes and equity in earnings (losses) of investees									22,936	(227,990)	42,190
Income tax expense									(101)	(86)	(117)
Equity in earnings of investees									35,518	18,640	10,963
Income (loss) from continuing operations									58,353	(209,436)	53,036
Loss from discontinued operations									(589)	(525)	3,498
Income (loss) before gain on sale of property									57,764	(209,961)	56,534
Gain on sale of property									79	0	0
Net income (loss)	12,065	$ 11,578	$ 16,813	$ 17,387	(2,339)	$ 16,911	$ (191,163)	$ (33,370)	57,843	(209,961)	56,534
Total assets	2,385,066				2,168,510				2,385,066	2,168,510	2,419,908
Operating Segments | Investment in Real Estate
Segment Reporting Information [Line Items]
Rental income									258,180	248,549	251,031
Expenses:
Real estate taxes									30,703	29,906	28,389
Utility expenses									17,269	17,916	19,369
Other operating expenses									54,290	50,425	45,982
Depreciation and amortization									73,153	68,696	66,593
Loss on impairment of real estate											2,016
Acquisition related costs									1,191	561	1,344
Total expenses									176,606	167,504	163,693
Operating income (loss)									81,574	81,045	87,338
Interest income									124	10
Interest expense									(2,375)	(7,908)	(7,820)
Gain (loss) on early extinguishment of debt									104	34
Income (loss) from continuing operations before income taxes and equity in earnings (losses) of investees									79,427	73,181	79,518
Income (loss) from continuing operations									79,427	73,181	79,518
Loss from discontinued operations									(589)	(525)	3,498
Income (loss) before gain on sale of property									78,838
Gain on sale of property									79
Net income (loss)									78,917	72,656	83,016
Total assets	1,807,560				1,639,462				1,807,560	1,639,462	1,713,361
Operating Segments | Investment in SIR
Expenses:
Net gain (loss) on issuance of shares by Select Income REIT									86	(42,145)	(53)
Loss on impairment of Select Income REIT investment										(203,297)
Income (loss) from continuing operations before income taxes and equity in earnings (losses) of investees									86	(245,442)	(53)
Equity in earnings of investees									35,381	18,620	10,876
Income (loss) from continuing operations									35,467	(226,822)	10,823
Income (loss) before gain on sale of property									35,467
Gain on sale of property									0
Net income (loss)									35,467	(226,822)	10,823
Total assets	487,708				491,369				487,708	491,369	680,137
Corporate
Expenses:
Acquisition related costs										250
General and administrative									14,897	14,826	15,809
Total expenses									14,897	15,076	15,809
Operating income (loss)									(14,897)	(15,076)	(15,809)
Dividend income									971	811
Interest income									34	4	69
Interest expense									(42,685)	(29,100)	(20,228)
Gain (loss) on early extinguishment of debt											1,307
Loss on distribution to common shareholders of The RMR Group Inc. common stock										(12,368)
Income (loss) from continuing operations before income taxes and equity in earnings (losses) of investees									(56,577)	(55,729)	(37,275)
Income tax expense									(101)	(86)	(117)
Equity in earnings of investees									137	20	87
Income (loss) from continuing operations									(56,541)	(55,795)	(37,305)
Income (loss) before gain on sale of property									(56,541)
Gain on sale of property									0
Net income (loss)									(56,541)	(55,795)	(37,305)
Total assets	$ 89,798				$ 37,679				$ 89,798	$ 37,679	$ 26,410

Selected Quarterly Financial 58

Selected Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	Dec. 14, 2015	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Quarterly Financial Data [Abstract]
Rental income		$ 66,030	$ 64,478	$ 64,061	$ 63,611	$ 61,685	$ 62,092	$ 62,113	$ 62,659	$ 258,180	$ 248,549	$ 251,031
Net income (loss)		$ 12,065	$ 11,578	$ 16,813	$ 17,387	$ (2,339)	$ 16,911	$ (191,163)	$ (33,370)	$ 57,843	$ (209,961)	$ 56,534
Net income (loss) per common share (basic and diluted) (in dollars per share)		$ 0.17	$ 0.16	$ 0.24	$ 0.24	$ (0.03)	$ 0.24	$ (2.71)	$ (0.47)	$ 0.81	$ (2.97)	$ 0.92
Common distributions declared (in dollars per share)		$ 0.43	$ 0.43	$ 0.43	$ 0.43	0.56	$ 0.43	$ 0.43	$ 0.43	$ 1.72	$ 1.72	$ 1.72
Non-cash distribution, per share, related to distribution of shares (in dollars per share)	$ 0.1284					$ 0.13

SCHEDULE III REAL ESTATE AND 59

SCHEDULE III REAL ESTATE AND ACCUMULATED DEPRECIATION (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Real estate and accumulated depreciation
Encumbrances	$ 27,837
Initial Cost to Company
Land	266,943
Buildings and Equipment	1,464,432
Costs Capitalized Subsequent to Acquisition	157,385
Cost amount carried at Close of Period
Land	267,855
Buildings and Equipment	1,620,905
Total	1,888,760	$ 1,696,132	$ 1,682,480	$ 1,568,562
Accumulated Depreciation	(296,804)	$ (255,879)	$ (219,791)	$ (187,635)
Mortgage debt, net	329
Aggregate cost for federal income tax purposes	$ 2,223,207
Useful life of buildings and improvements	40 years
Useful life of equipment	12 years
131 Clayton Street, Montgomery, AL
Initial Cost to Company
Land	$ 920
Buildings and Equipment	9,084
Costs Capitalized Subsequent to Acquisition	16
Cost amount carried at Close of Period
Land	920
Buildings and Equipment	9,100
Total	10,020
Accumulated Depreciation	(1,251)
4344 Carmichael Road, Montgomery, AL
Initial Cost to Company
Land	1,374
Buildings and Equipment	11,658
Cost amount carried at Close of Period
Land	1,374
Buildings and Equipment	11,658
Total	13,032
Accumulated Depreciation	(874)
15451 North 28th Avenue, Phoenix, AZ
Initial Cost to Company
Land	1,917
Buildings and Equipment	7,416
Costs Capitalized Subsequent to Acquisition	67
Cost amount carried at Close of Period
Land	1,917
Buildings and Equipment	7,483
Total	9,400
Accumulated Depreciation	(434)
711 14th Avenue, Safford, AZ
Initial Cost to Company
Land	460
Buildings and Equipment	11,708
Costs Capitalized Subsequent to Acquisition	265
Cost amount carried at Close of Period
Land	460
Buildings and Equipment	11,973
Total	12,433
Accumulated Depreciation	(1,924)
5045 East Butler Street, Fresno, CA
Initial Cost to Company
Land	7,277
Buildings and Equipment	61,118
Costs Capitalized Subsequent to Acquisition	58
Cost amount carried at Close of Period
Land	7,277
Buildings and Equipment	61,175
Total	68,452
Accumulated Depreciation	(21,968)
10949 N. Mather Boulevard, Rancho Cordova, CA
Initial Cost to Company
Land	562
Buildings and Equipment	16,923
Costs Capitalized Subsequent to Acquisition	100
Cost amount carried at Close of Period
Land	562
Buildings and Equipment	17,023
Total	17,585
Accumulated Depreciation	(1,341)
11020 Sun Center Drive, Rancho Cordova, CA
Initial Cost to Company
Land	1,465
Buildings and Equipment	8,537
Costs Capitalized Subsequent to Acquisition	0
Cost amount carried at Close of Period
Land	1,465
Buildings and Equipment	8,537
Total	10,002
Accumulated Depreciation	0
801 K Street, Sacramento, CA
Initial Cost to Company
Land	4,688
Buildings and Equipment	61,722
Costs Capitalized Subsequent to Acquisition	3,368
Cost amount carried at Close of Period
Land	4,688
Buildings and Equipment	65,090
Total	69,778
Accumulated Depreciation	(1,425)
9800 Goethe Road, Sacramento, CA
Initial Cost to Company
Land	1,550
Buildings and Equipment	12,263
Costs Capitalized Subsequent to Acquisition	1,520
Cost amount carried at Close of Period
Land	1,550
Buildings and Equipment	13,783
Total	15,333
Accumulated Depreciation	(2,773)
9815 Goethe Road, Sacramento, CA
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	(1,444)
Capital Place, Sacramento, CA
Initial Cost to Company
Land	2,290
Buildings and Equipment	35,891
Costs Capitalized Subsequent to Acquisition	5,695
Cost amount carried at Close of Period
Land	2,290
Buildings and Equipment	41,586
Total	43,876
Accumulated Depreciation	(6,858)
4181 Ruffin Road, San Diego, CA
Initial Cost to Company
Land	5,250
Buildings and Equipment	10,549
Costs Capitalized Subsequent to Acquisition	3,737
Cost amount carried at Close of Period
Land	5,250
Buildings and Equipment	14,286
Total	19,536
Accumulated Depreciation	(2,738)
4560 Viewridge Road, San Diego, CA
Initial Cost to Company
Land	4,269
Buildings and Equipment	18,316
Costs Capitalized Subsequent to Acquisition	2,795
Cost amount carried at Close of Period
Land	4,347
Buildings and Equipment	21,033
Total	25,380
Accumulated Depreciation	(9,234)
Sky Park Centre, San Diego, CA
Initial Cost to Company
Land	685
Buildings and Equipment	5,530
Costs Capitalized Subsequent to Acquisition	1,689
Cost amount carried at Close of Period
Land	685
Buildings and Equipment	7,219
Total	7,904
Accumulated Depreciation	(2,205)
Turning Basin Business Park, Stockton, CA
Initial Cost to Company
Land	563
Buildings and Equipment	5,469
Costs Capitalized Subsequent to Acquisition	0
Cost amount carried at Close of Period
Land	563
Buildings and Equipment	5,469
Total	6,032
Accumulated Depreciation	(604)
16194 West 45th Street, Golden, CO
Initial Cost to Company
Land	495
Buildings and Equipment	152
Costs Capitalized Subsequent to Acquisition	6,457
Cost amount carried at Close of Period
Land	495
Buildings and Equipment	6,608
Total	7,103
Accumulated Depreciation	(3,121)
12795 West Alameda Parkway, Lakewood, CO
Real estate and accumulated depreciation
Encumbrances	5,218
Initial Cost to Company
Land	2,640
Buildings and Equipment	23,777
Costs Capitalized Subsequent to Acquisition	1,045
Cost amount carried at Close of Period
Land	2,640
Buildings and Equipment	24,822
Total	27,462
Accumulated Depreciation	(4,303)
Corporate Center, Lakewood, CO
Initial Cost to Company
Land	2,887
Buildings and Equipment	27,538
Costs Capitalized Subsequent to Acquisition	3,850
Cost amount carried at Close of Period
Land	2,887
Buildings and Equipment	31,386
Total	34,273
Accumulated Depreciation	(10,667)
20 Massachusetts Avenue, Washington, DC
Initial Cost to Company
Land	12,005
Buildings and Equipment	51,528
Costs Capitalized Subsequent to Acquisition	20,952
Cost amount carried at Close of Period
Land	12,228
Buildings and Equipment	72,261
Total	84,489
Accumulated Depreciation	(31,369)
625 Indiana Avenue, Washington DC, DC
Initial Cost to Company
Land	26,000
Buildings and Equipment	25,955
Costs Capitalized Subsequent to Acquisition	5,799
Cost amount carried at Close of Period
Land	26,000
Buildings and Equipment	31,754
Total	57,754
Accumulated Depreciation	(5,233)
7850 Southwest 6th Court, Plantation, FL
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	(4,421)
8900 Grand Oak Circle, Tampa, FL
Real estate and accumulated depreciation
Encumbrances	8,778
Initial Cost to Company
Land	1,100
Buildings and Equipment	11,773
Costs Capitalized Subsequent to Acquisition	169
Cost amount carried at Close of Period
Land	1,100
Buildings and Equipment	11,942
Total	13,042
Accumulated Depreciation	(1,866)
181 Spring Street NW, Atlanta, GA
Initial Cost to Company
Land	5,718
Buildings and Equipment	20,017
Costs Capitalized Subsequent to Acquisition	131
Cost amount carried at Close of Period
Land	5,718
Buildings and Equipment	20,147
Total	25,865
Accumulated Depreciation	(2,210)
Corporate Square, Atlanta, GA
Initial Cost to Company
Land	3,996
Buildings and Equipment	29,762
Costs Capitalized Subsequent to Acquisition	9,952
Cost amount carried at Close of Period
Land	3,996
Buildings and Equipment	39,714
Total	43,710
Accumulated Depreciation	(10,410)
Executive Park, Atlanta, GA
Initial Cost to Company
Land	1,521
Buildings and Equipment	11,826
Costs Capitalized Subsequent to Acquisition	3,869
Cost amount carried at Close of Period
Land	1,521
Buildings and Equipment	15,695
Total	17,216
Accumulated Depreciation	(4,478)
One Georgia Center, Atlanta, GA
Initial Cost to Company
Land	10,250
Buildings and Equipment	27,933
Costs Capitalized Subsequent to Acquisition	882
Cost amount carried at Close of Period
Land	10,250
Buildings and Equipment	28,815
Total	39,065
Accumulated Depreciation	(3,759)
4712 Southpark Boulevard, Ellenwood, GA
Initial Cost to Company
Land	1,390
Buildings and Equipment	19,635
Costs Capitalized Subsequent to Acquisition	35
Cost amount carried at Close of Period
Land	1,390
Buildings and Equipment	19,670
Total	21,060
Accumulated Depreciation	(2,168)
South Vinnell Way, Boise, ID
Initial Cost to Company
Land	3,390
Buildings and Equipment	29,026
Costs Capitalized Subsequent to Acquisition	793
Cost amount carried at Close of Period
Land	3,390
Buildings and Equipment	29,819
Total	33,209
Accumulated Depreciation	(3,252)
2020 S. Arlington Heights, Arlington Heights, IL
Initial Cost to Company
Land	1,450
Buildings and Equipment	13,160
Costs Capitalized Subsequent to Acquisition	926
Cost amount carried at Close of Period
Land	1,450
Buildings and Equipment	14,086
Total	15,536
Accumulated Depreciation	(2,591)
Intech Park, Indianapolis, IN
Initial Cost to Company
Land	4,170
Buildings and Equipment	68,888
Costs Capitalized Subsequent to Acquisition	2,886
Cost amount carried at Close of Period
Land	4,170
Buildings and Equipment	71,774
Total	75,944
Accumulated Depreciation	(9,620)
400 State Street, Kansas City, KS
Initial Cost to Company
Land	640
Buildings and Equipment	9,932
Costs Capitalized Subsequent to Acquisition	3,108
Cost amount carried at Close of Period
Land	640
Buildings and Equipment	13,040
Total	13,680
Accumulated Depreciation	(1,992)
7125 Industrial Road, Florence, KY
Initial Cost to Company
Land	1,698
Buildings and Equipment	11,722
Costs Capitalized Subsequent to Acquisition	17
Cost amount carried at Close of Period
Land	1,698
Buildings and Equipment	11,739
Total	13,437
Accumulated Depreciation	(1,174)
251 Causeway Street, Boston, MA
Initial Cost to Company
Land	5,100
Buildings and Equipment	17,293
Costs Capitalized Subsequent to Acquisition	1,336
Cost amount carried at Close of Period
Land	5,100
Buildings and Equipment	18,629
Total	23,729
Accumulated Depreciation	(2,858)
75 Pleasant Street, Malden, MA
Initial Cost to Company
Land	1,050
Buildings and Equipment	31,086
Costs Capitalized Subsequent to Acquisition	132
Cost amount carried at Close of Period
Land	1,050
Buildings and Equipment	31,218
Total	32,268
Accumulated Depreciation	(5,168)
25 Newport Avenue, Quincy, MA
Initial Cost to Company
Land	2,700
Buildings and Equipment	9,199
Costs Capitalized Subsequent to Acquisition	809
Cost amount carried at Close of Period
Land	2,700
Buildings and Equipment	10,008
Total	12,708
Accumulated Depreciation	(1,391)
One Montvale Avenue, Stoneham, MA
Initial Cost to Company
Land	1,670
Buildings and Equipment	11,035
Costs Capitalized Subsequent to Acquisition	1,599
Cost amount carried at Close of Period
Land	1,670
Buildings and Equipment	12,634
Total	14,304
Accumulated Depreciation	(1,941)
4201 Patterson Avenue, Baltimore, MD
Initial Cost to Company
Land	901
Buildings and Equipment	8,097
Costs Capitalized Subsequent to Acquisition	3,472
Cost amount carried at Close of Period
Land	901
Buildings and Equipment	11,568
Total	12,469
Accumulated Depreciation	(4,103)
20400 Century Boulevard, Germantown, MD
Initial Cost to Company
Land	2,306
Buildings and Equipment	9,890
Costs Capitalized Subsequent to Acquisition	538
Cost amount carried at Close of Period
Land	2,347
Buildings and Equipment	10,386
Total	12,733
Accumulated Depreciation	(5,023)
3300 75th Avenue, Landover, MD
Initial Cost to Company
Land	4,110
Buildings and Equipment	36,371
Costs Capitalized Subsequent to Acquisition	607
Cost amount carried at Close of Period
Land	4,110
Buildings and Equipment	36,978
Total	41,088
Accumulated Depreciation	(6,311)
Rockville Pike1401 Rockville M D [Member]
Initial Cost to Company
Land	3,248
Buildings and Equipment	29,258
Costs Capitalized Subsequent to Acquisition	15,797
Cost amount carried at Close of Period
Land	3,248
Buildings and Equipment	45,058
Total	48,306
Accumulated Depreciation	(15,204)
2115 East Jefferson Street, North Bethesda, MD
Initial Cost to Company
Land	3,349
Buildings and Equipment	11,152
Costs Capitalized Subsequent to Acquisition	271
Cost amount carried at Close of Period
Land	3,349
Buildings and Equipment	11,423
Total	14,772
Accumulated Depreciation	(939)
Rutherford Business Park, Windsor Mill, MD
Initial Cost to Company
Land	1,598
Buildings and Equipment	10,219
Cost amount carried at Close of Period
Land	1,598
Buildings and Equipment	10,219
Total	11,817
Accumulated Depreciation	(1,043)
Meadows Business Park, Woodlawn, MD
Initial Cost to Company
Land	3,735
Buildings and Equipment	21,509
Costs Capitalized Subsequent to Acquisition	902
Cost amount carried at Close of Period
Land	3,735
Buildings and Equipment	22,411
Total	26,146
Accumulated Depreciation	(3,232)
11411 E. Jefferson Avenue, Detroit, MI
Initial Cost to Company
Land	630
Buildings and Equipment	18,002
Costs Capitalized Subsequent to Acquisition	23
Cost amount carried at Close of Period
Land	630
Buildings and Equipment	18,025
Total	18,655
Accumulated Depreciation	(3,001)
330 South Second Avenue, Minneapolis, MN
Initial Cost to Company
Land	3,991
Buildings and Equipment	18,186
Costs Capitalized Subsequent to Acquisition	9,534
Cost amount carried at Close of Period
Land	3,991
Buildings and Equipment	27,719
Total	31,710
Accumulated Depreciation	(4,474)
Rosedale Corporate Plaza, Roseville, MN
Initial Cost to Company
Land	672
Buildings and Equipment	6,045
Costs Capitalized Subsequent to Acquisition	1,465
Cost amount carried at Close of Period
Land	672
Buildings and Equipment	7,510
Total	8,182
Accumulated Depreciation	(2,915)
1300 Summit Street, Kansas City, MO
Initial Cost to Company
Land	2,776
Buildings and Equipment	12,070
Costs Capitalized Subsequent to Acquisition	227
Cost amount carried at Close of Period
Land	2,776
Buildings and Equipment	12,297
Total	15,073
Accumulated Depreciation	(1,303)
4241-4300 NE 34th Street, Kansas City, MO
Initial Cost to Company
Land	1,443
Buildings and Equipment	6,193
Costs Capitalized Subsequent to Acquisition	2,930
Cost amount carried at Close of Period
Land	1,780
Buildings and Equipment	8,786
Total	10,566
Accumulated Depreciation	(3,654)
1220 Echelon Parkway, Jackson, MS
Initial Cost to Company
Land	440
Buildings and Equipment	25,458
Costs Capitalized Subsequent to Acquisition	48
Cost amount carried at Close of Period
Land	440
Buildings and Equipment	25,506
Total	25,946
Accumulated Depreciation	(2,820)
10-12 Celina Avenue, Nashua, NH
Initial Cost to Company
Land	3,000
Buildings and Equipment	14,052
Costs Capitalized Subsequent to Acquisition	439
Cost amount carried at Close of Period
Land	3,000
Buildings and Equipment	14,491
Total	17,491
Accumulated Depreciation	(2,642)
50 West State Street, Trenton, NJ
Initial Cost to Company
Land	5,000
Buildings and Equipment	38,203
Costs Capitalized Subsequent to Acquisition	1,864
Cost amount carried at Close of Period
Land	5,000
Buildings and Equipment	40,067
Total	45,067
Accumulated Depreciation	(5,918)
435 Montano Boulevard, Albuquerque, NM
Initial Cost to Company
Land	710
Buildings and Equipment	1,651
Costs Capitalized Subsequent to Acquisition	57
Cost amount carried at Close of Period
Land	710
Buildings and Equipment	1,708
Total	2,418
Accumulated Depreciation	(271)
138 Delaware Avenue, Buffalo, NY
Initial Cost to Company
Land	4,405
Buildings and Equipment	18,899
Costs Capitalized Subsequent to Acquisition	5,010
Cost amount carried at Close of Period
Land	4,485
Buildings and Equipment	23,829
Total	28,314
Accumulated Depreciation	(10,308)
Airline Corporate Center, Colonie, NY
Initial Cost to Company
Land	790
Buildings and Equipment	6,400
Costs Capitalized Subsequent to Acquisition	13
Cost amount carried at Close of Period
Land	790
Buildings and Equipment	6,413
Total	7,203
Accumulated Depreciation	(720)
5000 Corporate Court, Holtsville, NY
Initial Cost to Company
Land	6,530
Buildings and Equipment	17,711
Costs Capitalized Subsequent to Acquisition	2,179
Cost amount carried at Close of Period
Land	6,530
Buildings and Equipment	19,890
Total	26,420
Accumulated Depreciation	(2,585)
305 East 46th Street, New York, NY
Initial Cost to Company
Land	36,800
Buildings and Equipment	66,661
Costs Capitalized Subsequent to Acquisition	3,596
Cost amount carried at Close of Period
Land	36,800
Buildings and Equipment	70,257
Total	107,057
Accumulated Depreciation	(9,436)
4600 25th Avenue, Salem, OR
Initial Cost to Company
Land	6,510
Buildings and Equipment	17,973
Costs Capitalized Subsequent to Acquisition	4,187
Cost amount carried at Close of Period
Land	6,510
Buildings and Equipment	22,160
Total	28,670
Accumulated Depreciation	(3,264)
Synergy Business Park, Columbia, SC
Initial Cost to Company
Land	1,439
Buildings and Equipment	11,143
Costs Capitalized Subsequent to Acquisition	4,751
Cost amount carried at Close of Period
Land	1,439
Buildings and Equipment	15,894
Total	17,333
Accumulated Depreciation	(3,108)
One Memphis Place, Memphis, TN
Initial Cost to Company
Land	1,630
Buildings and Equipment	5,645
Costs Capitalized Subsequent to Acquisition	2,421
Cost amount carried at Close of Period
Land	1,630
Buildings and Equipment	8,066
Total	9,696
Accumulated Depreciation	(1,168)
701 Clay Road, Waco, TX
Initial Cost to Company
Land	2,030
Buildings and Equipment	8,708
Costs Capitalized Subsequent to Acquisition	2,779
Cost amount carried at Close of Period
Land	2,060
Buildings and Equipment	11,457
Total	13,517
Accumulated Depreciation	(4,675)
14660,14672 and 14668 Lee Road, Chantilly, VA
Initial Cost to Company
Land	6,974
Buildings and Equipment	74,116
Costs Capitalized Subsequent to Acquisition	0
Cost amount carried at Close of Period
Land	6,974
Buildings and Equipment	74,116
Total	81,090
Accumulated Depreciation	0
Enterchange at Meadowville, Chester, VA
Initial Cost to Company
Land	1,478
Buildings and Equipment	9,594
Costs Capitalized Subsequent to Acquisition	256
Cost amount carried at Close of Period
Land	1,478
Buildings and Equipment	9,850
Total	11,328
Accumulated Depreciation	(813)
3920 Pender Drive, Fairfax, VA
Initial Cost to Company
Land	2,963
Buildings and Equipment	12,840
Costs Capitalized Subsequent to Acquisition	11
Cost amount carried at Close of Period
Land	2,963
Buildings and Equipment	12,852
Total	15,815
Accumulated Depreciation	(883)
Pender Business Park, Fairfax, VA
Real estate and accumulated depreciation
Encumbrances	13,841
Initial Cost to Company
Land	2,529
Buildings and Equipment	21,386
Costs Capitalized Subsequent to Acquisition	189
Cost amount carried at Close of Period
Land	2,529
Buildings and Equipment	21,575
Total	24,104
Accumulated Depreciation	(1,773)
1759 & 1760 Business Park Drive Reston, VA
Initial Cost to Company
Land	9,066
Buildings and Equipment	78,658
Costs Capitalized Subsequent to Acquisition	1,906
Cost amount carried at Close of Period
Land	9,066
Buildings and Equipment	80,564
Total	89,630
Accumulated Depreciation	(5,137)
9960 Mayland Drive, Richmond VA
Initial Cost to Company
Land	2,614
Buildings and Equipment	15,930
Costs Capitalized Subsequent to Acquisition	1,244
Cost amount carried at Close of Period
Land	2,614
Buildings and Equipment	17,174
Total	19,788
Accumulated Depreciation	(1,066)
Aquia Commerce Center, Stafford, VA
Initial Cost to Company
Land	2,090
Buildings and Equipment	7,465
Costs Capitalized Subsequent to Acquisition	730
Cost amount carried at Close of Period
Land	2,090
Buildings and Equipment	8,195
Total	10,285
Accumulated Depreciation	(1,070)
65 Bowdoin Street, S. Burlington, VT
Initial Cost to Company
Land	700
Buildings and Equipment	8,416
Costs Capitalized Subsequent to Acquisition	120
Cost amount carried at Close of Period
Land	700
Buildings and Equipment	8,536
Total	9,236
Accumulated Depreciation	(1,439)
840 North Broadway, Everett, WA
Initial Cost to Company
Land	3,360
Buildings and Equipment	15,376
Costs Capitalized Subsequent to Acquisition	1,346
Cost amount carried at Close of Period
Land	3,360
Buildings and Equipment	16,722
Total	20,082
Accumulated Depreciation	(1,933)
Stevens Center, Richland, WA
Initial Cost to Company
Land	3,970
Buildings and Equipment	17,035
Costs Capitalized Subsequent to Acquisition	1,606
Cost amount carried at Close of Period
Land	4,042
Buildings and Equipment	18,569
Total	22,611
Accumulated Depreciation	(8,640)
11050 West Liberty Drive, Milwaukee, WI
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	(645)
2029 Stonewall Jackson Drive, Falling Waters, WV
Initial Cost to Company
Land	906
Buildings and Equipment	3,886
Costs Capitalized Subsequent to Acquisition	270
Cost amount carried at Close of Period
Land	922
Buildings and Equipment	4,140
Total	5,062
Accumulated Depreciation	(2,005)
5353 Yellowstone Road, Cheyenne, WY
Initial Cost to Company
Land	1,915
Buildings and Equipment	8,217
Costs Capitalized Subsequent to Acquisition	531
Cost amount carried at Close of Period
Land	1,950
Buildings and Equipment	8,713
Total	10,663
Accumulated Depreciation	(4,218)
5600 Columbia Pike, Falls Church, VA
Initial Cost to Company
Land	3,519
Buildings and Equipment	15,098
Costs Capitalized Subsequent to Acquisition	4,065
Impairment/ Writedowns	(10,423)
Cost amount carried at Close of Period
Land	3,044
Buildings and Equipment	9,216
Total	12,260
Total Real Estate Assets
Real estate and accumulated depreciation
Encumbrances	27,837
Initial Cost to Company
Land	270,462
Buildings and Equipment	1,479,530
Costs Capitalized Subsequent to Acquisition	161,450
Impairment/ Writedowns	(10,423)
Cost amount carried at Close of Period
Land	270,899
Buildings and Equipment	1,630,121
Total	1,901,020
Accumulated Depreciation	$ (296,804)

SCHEDULE III REAL ESTATE AND 60

SCHEDULE III REAL ESTATE AND ACCUMULATED DEPRECIATION - Carrying Amount and Accumulated Depreciation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Real Estate Properties
Balance at the beginning of the period	$ 1,696,132	$ 1,682,480	$ 1,568,562
Additions	194,107	19,622	151,316
Loss on asset impairment			(7,058)
Disposals	(1,479)	(2,624)	(444)
Reclassification of assets held for sale		(3,346)	(29,896)
Balance at the end of the period	1,888,760	1,696,132	1,682,480
Accumulated Depreciation
Balance at the beginning of the period	255,879	219,791	187,635
Additions	42,404	38,987	37,671
Loss on asset impairment			(5,071)
Disposals	(1,479)	(2,624)	(444)
Reclassification of assets held for sale		(275)	0
Balance at the end of the period	$ 296,804	$ 255,879	$ 219,791