Diversified Healthcare Trust (DHC) 10-Q 10 May 18 2018 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2018	May 09, 2018
Document and Entity Information
Entity Registrant Name	SENIOR HOUSING PROPERTIES TRUST
Entity Central Index Key	1,075,415
Document Type	10-Q
Document Period End Date	Mar. 31, 2018
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding (in shares)		237,628,781
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q1

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Real estate properties:
Land	$ 848,261	$ 824,879
Buildings and improvements	7,110,013	6,999,884
Total real estate properties, gross	7,958,274	7,824,763
Accumulated depreciation	(1,505,427)	(1,454,477)
Total real estate properties, net	6,452,847	6,370,286
Cash and cash equivalents	39,161	31,238
Restricted cash	14,080	16,083
Acquired real estate leases and other intangible assets, net	490,505	472,265
Other assets, net	387,471	404,147
Total assets	7,384,064	7,294,019
LIABILITIES AND EQUITY
Unsecured revolving credit facility	55,000	596,000
Unsecured term loans, net	547,666	547,460
Senior unsecured notes, net	2,213,811	1,725,662
Secured debt and capital leases, net	828,318	805,404
Accrued interest	35,075	17,987
Assumed real estate lease obligations, net	93,543	96,018
Other liabilities	194,534	228,300
Total liabilities	3,967,947	4,016,831
Commitments and contingencies
Equity attributable to common shareholders:
Common shares of beneficial interest, $.01 par value: 300,000,000 shares authorized, 237,628,781 and 237,630,409 shares issued and outstanding at March 31, 2018 and December 31, 2017, respectively	2,376	2,376
Additional paid in capital	4,609,274	4,609,316
Cumulative net income	2,089,090	1,766,495
Cumulative other comprehensive income	565	87,231
Cumulative distributions	(3,453,142)	(3,360,468)
Total equity attributable to common shareholders	3,248,163	3,104,950
Noncontrolling interest:
Total equity attributable to noncontrolling interest	167,954	172,238
Total equity	3,416,117	3,277,188
Total liabilities and equity	$ 7,384,064	$ 7,294,019

CONDENSED CONSOLIDATED BALANCE3

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Mar. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Common shares of beneficial interest, par value (in dollars per share)	$ 0.01	$ 0.01
Common shares of beneficial interest, shares authorized (in shares)	300,000,000	300,000,000
Common shares of beneficial interest, shares issued (in shares)	237,628,781	237,630,409
Common shares of beneficial interest, shares outstanding (in shares)	237,628,781	237,630,409

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Revenues:
Rental income	$ 173,728	$ 166,443
Residents fees and services	102,087	98,118
Total revenues	275,815	264,561
Expenses:
Property operating expenses	108,143	101,057
Depreciation and amortization	70,339	73,175
General and administrative	25,118	15,083
Acquisition and certain other transaction related costs	20	292
Total expenses	203,620	189,607
Operating income	72,195	74,954
Dividend income	659	659
Unrealized gains and losses on equity securities, net	27,241	0
Interest and other income	54	120
Interest expense	(43,552)	(43,488)
Loss on early extinguishment of debt	(130)	0
Income from continuing operations before income tax expense and equity in earnings of an investee	56,467	32,245
Income tax expense	(260)	(92)
Equity in earnings of an investee	44	128
Income before gain on sale of properties	56,251	32,281
Gain on sale of properties	181,154	0
Net income (loss)	237,405	32,281
Net income attributable to noncontrolling interest	(1,383)	(126)
Net income attributable to common shareholders	236,022	32,155
Other comprehensive income:
Unrealized gain on investments in available for sale securities	0	24,045
Equity in unrealized (loss) gain of an investee	(93)	122
Other comprehensive (loss) income	(93)	24,167
Comprehensive income	237,312	56,448
Comprehensive income attributable to common shareholders	$ 235,929	$ 56,322
Weighted average common shares outstanding (basic) (in shares)	237,478	237,391
Weighted average common shares outstanding (diluted) (in shares)	237,493	237,416
Per common share amounts (basic and diluted):
Net income attributable to common shareholders (in dollars per share)	$ 0.99	$ 0.14

CONDENSED CONSOLIDATED STATEME5

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Statement of Cash Flows [Abstract]
Net income	$ 237,405	$ 32,281
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation and amortization	70,339	73,175
Amortization of debt issuance costs and debt discounts and premiums	1,411	1,459
Straight line rental income	(2,993)	(3,429)
Amortization of acquired real estate leases and other intangible assets	(1,381)	(1,291)
Loss on early extinguishment of debt	130	0
Gain on sale of properties	(181,154)	0
Unrealized gains and losses on equity securities, net	(27,241)	0
Other non-cash adjustments	(943)	(943)
Equity in earnings of an investee	(44)	(128)
Change in assets and liabilities:
Other assets	3,097	3,901
Accrued interest	17,088	15,051
Other liabilities	(31,680)	(6,001)
Net cash provided by operating activities	84,034	114,075
Cash flows from investing activities:
Real estate acquisitions and deposits	(122,221)	(14,326)
Real estate improvements	(13,443)	(30,171)
Proceeds from sale of properties	216,013	0
Net cash provided by (used in) investing activities	80,349	(44,497)
Cash flows from financing activities:
Proceeds from issuance of senior unsecured notes, net	491,560	0
Proceeds from borrowings on revolving credit facility	316,000	94,000
Repayments of borrowings on revolving credit facility	(857,000)	(324,000)
Repayment of other debt	(6,166)	(2,929)
Loss on early extinguishment of debt settled in cash	(130)	0
Payment of debt issuance costs	(4,296)	0
Repurchase of common shares	(90)	0
Proceeds from noncontrolling interest, net	0	255,813
Distributions to noncontrolling interest	(5,667)	0
Distributions to shareholders	(92,674)	(92,642)
Net cash used in financing activities	(158,463)	(69,758)
Increase (decrease) in cash and cash equivalents and restricted cash	5,920	(180)
Cash and cash equivalents and restricted cash at beginning of period	47,321	35,578
Cash and cash equivalents and restricted cash at end of period	53,241	35,398
Supplemental cash flows information:
Interest paid	25,053	26,978
Non-cash investing activities:
Acquisitions funded by assumed debt	(27,798)	0
Non-cash financing activities:
Assumption of mortgage notes payable	$ 27,798	$ 0

CONDENSED CONSOLIDATED STATEME6

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical) Statement - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]
Cash and cash equivalents	$ 39,161	$ 31,238	$ 32,272
Restricted cash	14,080		3,126
Total cash and cash equivalents and restricted cash shown in the statements of cash flows	$ 53,241	$ 47,321	$ 35,398	$ 35,578

Basis of Presentation

Basis of Presentation	3 Months Ended
	Mar. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The accompanying condensed consolidated financial statements of Senior Housing Properties Trust and its subsidiaries, or we, us, or our, are unaudited. Certain information and disclosures required by U.S. generally accepted accounting principles, or GAAP, for complete financial statements have been condensed or omitted. We believe the disclosures made are adequate to make the information presented not misleading. However, the accompanying condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and notes contained in our Annual Report on Form 10-K for the year ended December 31, 2017 , or our Annual Report. In the opinion of management, all adjustments (consisting of normal recurring accruals) considered necessary for a fair statement of results for the interim period have been included. All intercompany transactions and balances with or among our consolidated subsidiaries have been eliminated. Operating results for interim periods are not necessarily indicative of the results that may be expected for the full year. The preparation of financial statements in conformity with GAAP requires us to make estimates and assumptions that affect reported amounts. Actual results could differ from those estimates. Significant estimates in our condensed consolidated financial statements include purchase price allocations, useful lives of fixed assets and impairment of real estate and intangible assets. In March 2017, we entered a joint venture with a sovereign investor for one of our properties leased to medical providers, medical related business, clinics and biotech laboratory tenants, or MOBs ( two buildings), located in Boston, Massachusetts. We have determined that this joint venture is a variable interest entity, or VIE, as defined under the Consolidation Topic of the Financial Accounting Standards Board, or FASB, Accounting Standards Codification. We concluded that we must consolidate this VIE because we have the power to direct the activities that most significantly impact the VIE’s economic performance and we have the obligation to absorb losses of, and the right to receive benefits from, the VIE that could be significant to the VIE, and therefore are the primary beneficiary of the VIE. The assets of this VIE were $1,091,281 and $1,102,986 as of March 31, 2018 and December 31, 2017 , respectively, and consist primarily of the net real estate owned by the joint venture. The liabilities of this VIE were $718,559 and $720,678 as of March 31, 2018 and December 31, 2017 , respectively, and consist primarily of the debt securing the property. The sovereign investor's interest in this consolidated entity is reflected as noncontrolling interest in our condensed consolidated financial statements. See Note 6 for further information about this joint venture.

Recent Accounting Pronouncement

Recent Accounting Pronouncements	3 Months Ended
	Mar. 31, 2018
Accounting Changes and Error Corrections [Abstract]
Recent Accounting Pronouncements	Recent Accounting Pronouncements On January 1, 2018, we adopted FASB Accounting Standards Update, or ASU, No. 2014-09 (and related clarifying guidance issued by the FASB), Revenue From Contracts With Customers, 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. A substantial portion of our revenue consists of rental income from leasing arrangements, including leases with residents at properties leased to our taxable REIT subsidiaries, or TRSs, which is specifically excluded from ASU No. 2014-09. We have adopted ASU No. 2014-09 using the modified retrospective approach. The adoption of ASU No. 2014-09 did not have a material impact on the amount or timing of our revenue recognition in our condensed consolidated financial statements. On January 1, 2018, we adopted FASB 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. The implementation of ASU No. 2016-01 resulted in the reclassification of historical changes in the fair value of our available for sale equity securities of $86,572 from cumulative other comprehensive income to cumulative net income. Effective January 1, 2018, changes in the fair value of our equity securities are recorded through earnings in accordance with ASU No. 2016-01. On January 1, 2018, we adopted FASB ASU No. 2016-18, Restricted Cash , which requires companies to show the changes in the total of cash and cash equivalents and restricted cash and restricted cash equivalents in the statement of cash flows. ASU No. 2016-18 also requires a reconciliation of the totals in the statement of cash flows to the related captions in the balance sheet. As a result, amounts included in restricted cash in our condensed consolidated balance sheets are presented with cash and cash equivalents in our condensed consolidated statements of cash flows to the related captions in the condensed consolidated balance sheets. Restricted cash totaled $14,080 and $3,126 as of March 31, 2018 and 2017, respectively. The implementation of ASU No. 2016-18 resulted in a $703 decrease to net cash provided by operating activities for the three months ended March 31, 2017. The adoption of ASU No. 2016-18 did not change our balance sheet presentation. 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 condensed 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 the adoption of ASU No. 2016-13 will have in our consolidated financial statements. We currently expect to adopt the standard using the modified retrospective approach.

Real Estate Properties

Real Estate Properties	3 Months Ended
	Mar. 31, 2018
Real Estate [Abstract]
Real Estate Properties	Real Estate Properties At March 31, 2018 , we owned 444 properties ( 470 buildings) located in 42 states and Washington, D.C., including two senior living communities classified as held for sale with a net carrying value of $18,479 as of March 31, 2018. Acquisitions: We have accounted for our 2018 acquisitions as acquisitions of assets unless otherwise noted. We funded our 2018 acquisitions using cash on hand and borrowings under our revolving credit facility, unless otherwise noted. Senior Living Community Acquisitions: In November 2017, we entered a transaction agreement with Five Star Senior Living Inc., or Five Star, pursuant to which we agreed to acquire six senior living communities from Five Star. In December 2017, we acquired two of these senior living communities located in Alabama and Indiana with a combined 229 living units for $39,457 , including closing costs of $307 . In January 2018, we acquired one of these senior living communities located in Tennessee with 88 living units for $19,868 , including closing costs of $201 . In February 2018, we acquired one of these senior living communities located in Arizona with 127 living units for $22,622 , including our assumption of an approximately $16,748 mortgage note and closing costs of $372 . In connection with our acquisition of these senior living communities, we entered management and pooling agreements with Five Star for Five Star to manage these senior living communities for us. The closings of the acquisitions of the remaining two senior living communities for an aggregate purchase price of $23,300 , including the assumption of approximately $16,800 of mortgage notes, are expected to occur by the end of the second quarter of 2018 as third party approvals are received and we expect to enter management and pooling agreements with Five Star concurrent with those acquisitions. These acquisitions are subject to conditions; these conditions may not be met and the remaining acquisitions may not be completed, may be delayed or the terms of these acquisitions or the management and pooling agreements for these communities may change. See Note 9 for further information regarding these transactions and transaction agreement. The table below represents the purchase price allocations (including net closing adjustments) of the senior living community acquisitions that closed during the three months ended March 31, 2018, as described above: Date Location Leased/Managed Number of Properties Units Cash Paid Plus Assumed Debt (1) Land Building and Improvements FF&E Acquired Real Estate Intangible Assets Assumed Debt Premium on Assumed Debt January 2018 Tennessee Managed 1 88 $ 19,868 $ 580 $ 14,884 $ 1,209 $ 3,195 $ — $ — February 2018 Arizona Managed 1 127 22,622 2,017 17,123 390 4,451 16,748 (1,359 ) 2 215 $ 42,490 $ 2,597 $ 32,007 $ 1,599 $ 7,646 $ 16,748 $ (1,359 ) (1) Cash paid plus assumed debt, if any, includes closing costs. MOBs: In January 2018, we acquired three MOBs ( three buildings) located in Kansas, Missouri and California with a total of approximately 400,000 square feet for an aggregate purchase price of approximately $91,698 , including closing costs of $544 . In March 2018, we acquired one MOB ( one building) located in Virginia with approximately 135,000 square feet for a purchase price of approximately $23,275 , including the assumption of a $11,050 mortgage note and closing costs of $525 . The table below represents the purchase price allocations (including net closing adjustments) of the MOB acquisitions that closed during the three months ended March 31, 2018, as described above: Date Location Number of Properties Number of Buildings Square Feet (000’s) Cash Paid Plus Assumed Debt (1) Land Building and Improvements Acquired Real Estate Leases (2) Assumed Debt January 2018 3 States 3 3 400 $ 91,698 $ 16,873 $ 54,605 $ 20,220 $ — March 2018 Virginia 1 1 135 23,275 2,863 11,105 9,307 11,050 4 4 535 $ 114,973 $ 19,736 $ 65,710 $ 29,527 $ 11,050 (1) Cash paid plus assumed debt, if any, includes closing costs. (2) The weighted average amortization period for acquired real estate leases as of the acquisition dates was 5.8 years. Impairment: We periodically evaluate our assets for impairments. Impairment indicators may include declining tenant or resident occupancy, weak or declining profitability from the property, decreasing tenant cash flows or liquidity, our decision to dispose of an asset before the end of its estimated useful life, and legislative, market or industry changes that could permanently reduce the value of an asset. If indicators of impairment are present, we evaluate the carrying value of the affected asset by comparing it to the expected future undiscounted net cash flows to be generated from that asset. If the sum of these expected future net cash flows is less than the carrying value, we reduce the net carrying value of the asset to its estimated fair value. We did not record any impairment charges for our real estate properties during the three months ended March 31, 2018 . Pacifica Senior Living, LLC: We lease eight senior living communities to affiliates of Pacifica Senior Living, LLC, or Pacifica, a privately owned company, with lease terms continuing until 2023. The rent payable to us under these leases is scheduled to increase at agreed upon times during the lease terms. A large majority of the tenants’ revenues at these senior living communities is derived from private resources. An affiliate of Pacifica has provided limited guarantees of these leases and the obligations under these leases are secured by deposits totaling approximately $3,277 . On January 31, 2018, the tenant of one of these senior living communities notified us that it will not pay the rent due for the applicable community. The annual rent we received in 2017 for this community was approximately $2,049 , including $105 of straight line rent adjustments. We held a security deposit of $583 for the rent due for this community and the limited guarantee for this community is equal to one year’s rent at this community. We used $528 of the security deposit to cover the rent and other amounts due for the three months ended March 31, 2018. We are currently in negotiations to transfer the operations of this community to another operator and are enforcing our rights under the applicable lease and guaranty. Dispositions: In March 2018, we sold two senior living communities that were leased to Sunrise Senior Living LLC, or Sunrise, for an aggregate sales price of $217,000 , excluding closing costs, resulting in a gain of $181,154 . We have agreed to sell an additional senior living community leased to Sunrise for a sales price of $96,000 and we expect the closing of this sale to occur before the end of the second quarter of 2018. We recognized rental income of $2,776 during the three months ended March 31, 2018 related to these three senior living communities. In March, 2018, we agreed to sell one skilled nursing facility, or SNF, a type of senior living community, that is leased to Five Star for a sales price of approximately $6,500 , excluding closing costs. We expect the closing of the sale of this SNF to occur before the end of 2018. Rental income will be reduced in accordance with our lease with Five Star upon the sale of this SNF. The two senior living communities that we have agreed to sell were classified as held for sale as of March 31, 2018 and had a net carrying value of $18,479 as of March 31, 2018. These pending sales are subject to conditions; accordingly, we cannot be sure that we will complete these sales or that these sales will not be delayed or their terms will not change.

Indebtedness

Indebtedness	3 Months Ended
	Mar. 31, 2018
Debt Disclosure [Abstract]
Indebtedness	Indebtedness Our principal debt obligations at March 31, 2018 were: (1) outstanding borrowings under our $1,000,000 unsecured revolving credit facility; (2) seven public issuances of senior unsecured notes, including: (a) $400,000 principal amount at an annual interest rate of 3.25% due 2019, (b) $200,000 principal amount at an annual interest rate of 6.75% due 2020, (c) $300,000 principal amount at an annual interest rate of 6.75% due 2021, (d) $250,000 principal amount at an annual interest rate of 4.75% due 2024, (e) $500,000 principal amount at an annual interest rate of 4.75% due 2028, (f) $350,000 principal amount at an annual interest rate of 5.625% due 2042 and (g) $250,000 principal amount at an annual interest rate of 6.25% due 2046; (3) our $350,000 principal amount unsecured term loan due 2020; (4) our $200,000 principal amount unsecured term loan due 2022; and (5) $818,457 aggregate principal amount of mortgages (excluding premiums, discounts and net debt issuance costs) secured by 24 of our properties ( 25 buildings) with maturity dates between 2018 and 2043. The 24 mortgaged properties ( 25 buildings) had a carrying value (before accumulated depreciation) of $1,245,304 at March 31, 2018 . We also had two properties subject to capital leases with lease obligations totaling $10,484 at March 31, 2018 ; these two properties had a carrying value (before accumulated depreciation) of $36,238 at March 31, 2018 , and the capital leases expire in 2026. In February 2018, we issued $500,000 of 4.75% senior unsecured notes due 2028, raising net proceeds of approximately $487,264 after underwriting discounts and expenses. We used the net proceeds of this offering to reduce amounts outstanding under our revolving credit facility. We have a $1,000,000 revolving credit facility that is available for general business purposes, including acquisitions. The maturity date of our revolving credit facility is January 15, 2022, and, subject to the payment of an extension fee and meeting other conditions, we have the option to extend the maturity date of the facility for an additional year. Our revolving credit facility provides that we can borrow, repay and re-borrow funds available under our revolving credit facility until maturity, and no principal repayment is due until maturity. Our revolving credit facility requires annual interest to be paid on borrowings at the rate of LIBOR plus a premium of 120 basis points, plus a facility fee of 25 basis points per annum on the total amount of lending commitments under the facility. The interest rate premium and facility fee are each subject to adjustment based upon changes to our credit ratings. As of March 31, 2018 , the annual interest rate payable on borrowings under our revolving credit facility was 2.9% . The weighted average annual interest rates for borrowings under our revolving credit facility were 2.7% and 2.1% for the three months ended March 31, 2018 and 2017 , respectively. As of March 31, 2018 , we had $55,000 outstanding and $945,000 available for borrowing, and as of May 9, 2018 , we had $35,000 outstanding and $965,000 available for borrowing under our revolving credit facility. We incurred interest expense and other associated costs related to our revolving credit facility of $4,077 and $2,830 for the three months ended March 31, 2018 and 2017 , respectively. The facility also includes a feature pursuant to which in certain circumstances maximum borrowings under the facility may be increased to up to $2,000,000 . Our $350,000 term loan matures in January 2020, and is prepayable without penalty at any time. This term loan requires annual interest to be paid at the rate of LIBOR plus a premium of 140 basis points, subject to adjustment based upon changes to our credit ratings. At March 31, 2018 , the annual interest rate payable on amounts outstanding under this term loan was 3.1% . The weighted average annual interest rate for amounts outstanding under this term loan was 3.1% and 2.2% for the three months ended March 31, 2018 and 2017 , respectively. We incurred interest expense and other associated costs related to this term loan of $2,766 and $2,043 for the three months ended March 31, 2018 and 2017 . This term loan includes an accordion feature under which maximum borrowings may be increased to up to $700,000 in certain circumstances. Our $200,000 term loan matures in September 2022, and is prepayable without penalty at any time. This term loan requires annual interest to be paid at the rate of LIBOR plus a premium of 135 basis points, subject to adjustment based upon changes to our credit ratings. At March 31, 2018 , the annual interest rate payable on amounts outstanding under this term loan was 3.2% . The weighted average annual interest rate for amounts outstanding under this term loan was 3.0% and 2.6% for the three months ended March 31, 2018 and 2017 , respectively. We incurred interest expense and other associated costs related to this term loan of $1,564 and $1,359 for the three months ended March 31, 2018 and 2017 , respectively. This term loan includes an accordion feature under which maximum borrowings may be increased to up to $400,000 in certain circumstances. Our revolving credit facility and term loan agreements and our senior unsecured notes indentures and their supplements provide for acceleration of payment of all amounts due thereunder upon the occurrence and continuation of certain events of default, such as, in the case of our revolving credit facility and term loan agreements, a change of control of us, as defined, which includes The RMR Group LLC, or RMR LLC, ceasing to act as our business and property manager. Our revolving credit facility and term loan agreements and our senior unsecured notes indentures and their supplements also contain a number of covenants, including covenants that restrict our ability to incur debts, and generally require us to maintain certain financial ratios, and our revolving credit facility and term loan agreements 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 revolving credit facility and term loan agreements and our senior unsecured notes indentures and their supplements at March 31, 2018 .

Fair Value of Assets and Liabil

Fair Value of Assets and Liabilities	3 Months Ended
	Mar. 31, 2018
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 March 31, 2018 , 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 Active Markets for Significant Other Unobservable Identical Assets Observable Inputs Inputs Description Total (Level 1) (Level 2) (Level 3) Recurring Fair Value Measurements Assets: Investment in RMR Inc. (1) $ 184,487 $ 184,487 $ — $ — Investment in Five Star (2) $ 5,506 $ 5,506 $ — $ — (1) Our 2,637,408 shares of class A common stock of The RMR Group Inc., or RMR Inc., which are included in other assets in our condensed 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 $69,826 as of March 31, 2018 . During the three months ended March 31, 2018 , we recorded an unrealized gain of $28,088 to adjust the carrying value of our investment in RMR Inc. class A common shares to their fair value. (2) Our 4,235,000 common shares of Five Star, which are included in other assets in our condensed 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 $6,353 as of March 31, 2018 . During the three months ended March 31, 2018 , we recorded an unrealized loss of $847 to adjust the carrying value of our investment in Five Star common shares to their fair value. In addition to the assets described in the table above, our financial instruments at March 31, 2018 and December 31, 2017 included cash and cash equivalents, restricted cash, other assets, our revolving credit facility, term loans, senior unsecured notes, secured debt and capital leases and other unsecured obligations and liabilities. The fair values of these financial instruments approximated their carrying values in our condensed consolidated financial statements as of such dates, except as follows: As of March 31, 2018 As of December 31, 2017 Description Carrying Amount (1) Estimated Fair Value Carrying Amount (1) Estimated Fair Value Senior unsecured notes $ 2,213,811 $ 2,292,648 $ 1,725,662 $ 1,810,882 Secured debts (2) 817,834 793,815 794,710 783,353 $ 3,031,645 $ 3,086,463 $ 2,520,372 $ 2,594,235 (1) Includes unamortized debt issuance costs, premiums and discounts. (2) We assumed certain of these secured debts in connection with our acquisitions of certain properties. We recorded the assumed secured debts at estimated fair value on the date of assumption and we are amortizing the fair value adjustments, if any, to interest expense over their respective terms to adjust interest expense to the estimated market interest rates as of the date of assumption. We estimated the fair value of our two issuances of senior unsecured notes due 2042 and 2046 based on the closing price on The Nasdaq Stock Market LLC, or Nasdaq, (a Level 1 input) as of March 31, 2018 . We estimated the fair values of our five issuances of senior unsecured notes due 2019, 2020, 2021, 2024 and 2028 using an average of the bid and ask price on or about March 31, 2018 (Level 2 inputs as defined in the fair value hierarchy under GAAP). We estimated the fair values of our secured debts by using discounted cash flows 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.

Noncontrolling Interest

Noncontrolling Interest	3 Months Ended
	Mar. 31, 2018
Noncontrolling Interest [Abstract]
Noncontrolling Interest	Noncontrolling Interest In March 2017, we entered a joint venture with a sovereign investor for one of our MOBs ( two buildings) located in Boston, Massachusetts. The investor contributed approximately $261,009 for a 45% equity interest in the joint venture, and we retained the remaining 55% equity interest in the joint venture. Net proceeds from this transaction were approximately $255,931 , after transaction costs. We continue to effectively control this property and therefore continue to account for this property on a consolidated basis in our condensed consolidated financial statements under the VIE model. We recognized a noncontrolling interest in our condensed consolidated balance sheets of approximately $181,859 as of completion of the transaction, which was equal to 45% of the aggregate carrying value of the total equity of the property immediately prior to the transaction. The difference between the net proceeds received from this transaction and the noncontrolling interest recognized, which was approximately $74,072 , has been reflected as an increase in additional paid in capital in our condensed consolidated balance sheets. The portion of the joint venture's net income and comprehensive income not attributable to us, or $1,383 and $126 for the three months ended March 31, 2018 and 2017, respectively, is reported as noncontrolling interest in our condensed consolidated statements of comprehensive income. We made aggregate cash distributions to our joint venture partner of $5,667 during the three months ended March 31, 2018 , which are reflected as a decrease in total equity attributable to noncontrolling interest in our condensed consolidated balance sheets. As of March 31, 2018 , this joint venture held real estate assets with an aggregate net book value of $759,654 , subject to mortgage notes of $620,000 . In assessing whether we have a controlling interest in this joint venture arrangement and are required to consolidate the accounts of the joint venture entity, we considered the members' rights to residual gains and obligation to absorb losses, which activities most significantly impact the economic performance of the entity and which member has the power to direct those activities.

Shareholders' Equity

Shareholders' Equity	3 Months Ended
	Mar. 31, 2018
Stockholders' Equity Note [Abstract]
Shareholders' Equity	Shareholders’ Equity Share Based Compensation: On March 29, 2018, in accordance with our Trustee compensation arrangements, we granted 3,000 of our common shares, valued at $15.66 per share, the closing price of our common shares on Nasdaq on that day, to our Managing Trustee, who was elected as a Managing Trustee on that day. On January 1, 2018, we purchased 4,628 of our common shares, valued at $19.15 per share, the closing price of our common shares on Nasdaq on December 29, 2017, from a former employee of RMR LLC in satisfaction of tax withholding and payment obligations in connection with the vesting of awards of our common shares. Distributions: On February 22, 2018 , we paid a regular quarterly distribution to common shareholders of $0.39 per share, or approximately $92,674 , that was declared on January 19, 2018 and was payable to shareholders of record on January 29, 2018. On April 19, 2018, we declared a regular quarterly distribution payable to common shareholders of record on April 30, 2018, of $0.39 per share, or approximately $92,675 . We expect to pay this distribution on or about May 17, 2018.

Segment Reporting

Segment Reporting	3 Months Ended
	Mar. 31, 2018
Segment Reporting [Abstract]
Segment Reporting	Segment Reporting As of March 31, 2018 , we have four operating segments, of which three are separate reporting segments. We aggregate the reporting units in each of our triple net leased senior living communities, our managed senior living communities and our MOBs into three reporting segments, based on their similar operating and economic characteristics. The first reporting segment includes triple net leased senior living communities that provide short term and long term residential care and other services for residents and with respect to which we receive rents from the operators. The second reporting segment includes managed senior living communities that provide short term and long term residential care and other services for residents where we pay fees to the operator to manage the communities for our account. The third reporting segment includes MOBs where the tenants pay us rent. Our fourth segment includes all of our other operations, including certain properties that offer wellness, fitness and spa services to members and with respect to which we receive rents from operators, which we do not consider to be sufficiently material to constitute a separate reporting segment. For the Three Months Ended March 31, 2018 Triple Net Leased Senior Living Communities Managed Senior Living Communities MOBs All Other Operations Consolidated Revenues: Rental income $ 67,975 $ — $ 101,151 $ 4,602 $ 173,728 Residents fees and services — 102,087 — — 102,087 Total revenues 67,975 102,087 101,151 4,602 275,815 Expenses: Property operating expenses — 77,205 30,938 — 108,143 Depreciation and amortization 20,195 14,811 34,385 948 70,339 General and administrative — — — 25,118 25,118 Acquisition and certain other transaction related costs — — — 20 20 Total expenses 20,195 92,016 65,323 26,086 203,620 Operating income (loss) 47,780 10,071 35,828 (21,484 ) 72,195 Dividend income — — — 659 659 Unrealized gains and losses on equity securities, net — — — 27,241 27,241 Interest and other income — — — 54 54 Interest expense (571 ) (1,327 ) (5,909 ) (35,745 ) (43,552 ) Loss on early extinguishment of debt — (130 ) — — (130 ) Income (loss) from continuing operations before income tax expense and equity in earnings of an investee 47,209 8,614 29,919 (29,275 ) 56,467 Income tax expense — — — (260 ) (260 ) Equity in earnings of an investee — — — 44 44 Income (loss) before gain on sale of properties 47,209 8,614 29,919 (29,491 ) 56,251 Gain on sale of properties 181,154 — — — 181,154 Net income (loss) 228,363 8,614 29,919 (29,491 ) 237,405 Net income attributable to noncontrolling interest — — (1,383 ) — (1,383 ) Net income (loss) attributable to common shareholders $ 228,363 $ 8,614 $ 28,536 $ (29,491 ) $ 236,022 As of March 31, 2018 Triple Net Leased Senior Living Communities Managed Senior Living Communities MOBs All Other Operations Consolidated Total assets $ 2,199,708 $ 1,313,777 $ 3,454,428 $ 416,151 $ 7,384,064 For the Three Months Ended March 31, 2017 Triple Net Leased Senior Living Communities Managed Senior Living Communities MOBs All Other Operations Consolidated Revenues: Rental income $ 67,252 $ — $ 94,646 $ 4,545 $ 166,443 Residents fees and services — 98,118 — — 98,118 Total revenues 67,252 98,118 94,646 4,545 264,561 Expenses: Property operating expenses — 73,880 27,177 — 101,057 Depreciation and amortization 20,334 20,215 31,678 948 73,175 General and administrative — — — 15,083 15,083 Acquisition and certain other transaction related costs — — — 292 292 Total expenses 20,334 94,095 58,855 16,323 189,607 Operating income (loss) 46,918 4,023 35,791 (11,778 ) 74,954 Dividend income — — — 659 659 Interest and other income — — — 120 120 Interest expense (5,339 ) (1,176 ) (6,321 ) (30,652 ) (43,488 ) Income (loss) from continuing operations before income tax expense and equity in earnings of an investee 41,579 2,847 29,470 (41,651 ) 32,245 Income tax expense — — — (92 ) (92 ) Equity in earnings of an investee — — — 128 128 Net income (loss) 41,579 2,847 29,470 (41,615 ) 32,281 Net income attributable to noncontrolling interest — — (126 ) — (126 ) Net income (loss) attributable to common shareholders $ 41,579 $ 2,847 $ 29,344 $ (41,615 ) $ 32,155 As of December 31, 2017 Triple Net Leased Senior Living Communities Managed Senior Living Communities MOBs All Other Operations Consolidated Total assets $ 2,251,756 $ 1,273,757 $ 3,367,485 $ 401,021 $ 7,294,019

Leases and Management Agreement

Leases and Management Agreements with Five Star	3 Months Ended
	Mar. 31, 2018
Risks and Uncertainties [Abstract]
Leases and Management Agreements with Five Star	Leases and Management Agreements with Five Star Our Senior Living Communities Leased by Five Star. We are Five Star’s largest landlord and Five Star is our largest tenant. As of March 31, 2018 and 2017 , we leased 185 senior living communities to Five Star. We lease senior living communities to Five Star pursuant to five leases. We recognized total rental income payable by Five Star of $51,759 , and $50,985 for the three months ended March 31, 2018 and 2017 , respectively. These amounts exclude percentage rent payments we received from Five Star of $1,374 and $1,445 for the three months ended March 31, 2018 and 2017 , respectively. We determine actual percentage rent due under our Five Star leases annually and recognize any resulting amount as rental income at year end when all contingencies are met. As of March 31, 2018 and December 31, 2017 , we had rents receivable from Five Star of $17,265 and $18,539 , respectively, which amounts are included in other assets in our condensed consolidated balance sheets. Rental income from Five Star represented 18.8% of our total revenues for the three months ended March 31, 2018 , and the properties Five Star leases from us represented 27.0% of our real estate investments, at cost, as of March 31, 2018 . Pursuant to the terms of our leases with Five Star, for the three months ended March 31, 2017, we funded $8,082 of improvements to communities leased to Five Star. As a result, the annual minimum rent payable to us by Five Star increased by approximately $648 as of March 31, 2017. We did not fund any capital improvements at communities leased to Five Star for the three months ended March 31, 2018. Our Senior Living Communities Managed by Five Star . As of March 31, 2018 and 2017 , Five Star managed 72 and 68 senior living communities for our account, respectively. We lease our senior living communities that are managed by Five Star and include assisted living units or SNF units to our TRSs and Five Star manages these communities pursuant to long term management agreements. See Note 3 for further information regarding senior living communities that we have acquired since December 2017 and which are managed by Five Star for our account. We incurred management fees payable to Five Star of $3,494 and $3,299 for the three months ended March 31, 2018 and 2017 , respectively. These amounts are included in property operating expenses or have been capitalized, as appropriate, in our condensed consolidated financial statements. Five Star also provides certain other services directly to residents at some of the senior living communities it manages for us, such as rehabilitation services. At senior living communities Five Star manages for us where Five Star provides rehabilitation services on an outpatient basis, the residents, third party payers or government programs pay Five Star for those rehabilitation services. At senior living communities Five Star manages for us where Five Star provides both inpatient and outpatient rehabilitation services, we generally pay Five Star for these services and charges for these services are included in amounts charged to residents, third party payers or government programs. We incurred fees payable to Five Star of $1,699 and $1,982 for the three months ended March 31, 2018 and 2017 , respectively, for rehabilitation services Five Star provided at senior living communities it manages for us; we include these amounts in property operating expenses in our condensed consolidated statement of comprehensive income.

Business and Property Managemen

Business and Property Management Agreements with RMR LLC	3 Months Ended
	Mar. 31, 2018
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 the property level operations of our MOBs. We also have a subsidiary level management agreement with RMR LLC related to one of our MOBs located in Boston, Massachusetts, which we entered in connection with the joint venture arrangement for that MOB. Under that agreement, our subsidiary pays RMR LLC certain business management fees directly, which fees are credited against the business management fees payable by us to RMR LLC. Pursuant to our business management agreement with RMR LLC, we recognized net business management fees of $23,323 and $12,781 for the three months ended March 31, 2018 and 2017 , respectively. The net business management fees we recognized for the three months ended March 31, 2018 include $725 of management fees related to our subsidiary level management agreement with RMR LLC entered in connection with our joint venture arrangement and $14,347 of estimated 2018 incentive fees based on our common share total return, as defined in our business management agreement, as of March 31, 2018 . Although we recognized estimated incentive fees in accordance with GAAP, the actual amount of incentive fees for 2018, if any, will be based on our common share total return, as defined in our business management agreement, for the three year period ending December 31, 2018, and will be payable in 2019. The net business management fees for the three months ended March 31, 2017, included $62 of management fees related to our subsidiary level management agreement with RMR LLC and $3,266 of estimated 2017 incentive fees based on our common share total return, as defined in our business management agreement, as of March 31, 2017. In January 2018, we paid RMR LLC an incentive fee of $55,740 for 2017. These amounts are included in general and administrative expenses in our condensed consolidated statements of comprehensive income. Pursuant to our property management agreement with RMR LLC, we recognized aggregate net property management and construction supervision fees of $2,821 and $2,590 for the three months ended March 31, 2018 and 2017 , respectively. These amounts are included in property operating expenses or have been capitalized, as appropriate, in our condensed consolidated financial statements. 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, including certain payroll and related costs incurred by RMR LLC, are generally incorporated into rents charged to our tenants. We reimbursed RMR LLC $2,779 and $2,379 for property management related expenses for the three months ended March 31, 2018 and 2017 , respectively, which amounts are included in property operating expenses in our condensed consolidated statements of comprehensive income. In addition, we are responsible for our share of RMR LLC's costs for providing our internal audit function. The amounts recognized as expense for internal audit costs were $69 and $67 for the three months ended March 31, 2018 and 2017 , respectively, which amounts are included in general and administrative expenses in our condensed consolidated statements of comprehensive income.

Related Person Transactions

Related Person Transactions	3 Months Ended
	Mar. 31, 2018
Related Party Transactions [Abstract]
Related Person Transactions	Related Person Transactions We have relationships and historical and continuing transactions with Five Star, RMR LLC, RMR Inc., Affiliates Insurance Company, or AIC, and others related to them, including other companies to which RMR LLC provides management services and which have trustees, directors and officers who are also our Trustees or officers. Five Star. We are currently one of Five Star’s largest stockholders. As of March 31, 2018 , we owned 4,235,000 of Five Star’s common shares, or approximately 8.4% of Five Star’s outstanding common shares. Five Star is our largest tenant and the manager of our managed senior living communities. RMR LLC provides management services to both us and Five Star. As of March 31, 2018 , a subsidiary of ABP Trust, the controlling shareholder of RMR Inc., owned 35.6% of Five Star's outstanding common shares. Adam D. Portnoy, one of our Managing Trustees, is the sole trustee of ABP Trust and a managing director of Five Star. See Note 9 for further information regarding our relationships, agreements and transactions with Five Star and Note 5 for further information regarding our investment in Five Star. Our Manager, RMR LLC. We have two agreements with RMR LLC to provide management services to us. See Note 10 for further information regarding our management agreements with RMR LLC. RMR Inc. RMR LLC is a majority owned subsidiary of RMR Inc. and RMR Inc. is the managing member of RMR LLC. Adam D. Portnoy, one of our Managing Trustees, is the sole trustee, controlling shareholder and an officer of ABP Trust, the controlling shareholder of RMR Inc., a managing director, president and chief executive officer of RMR Inc., and an officer of ABP Trust and RMR LLC. Jennifer B. Clark, our other Managing Trustee, also serves as a managing director and as executive vice president, general counsel and secretary of RMR Inc. and an officer of ABP Trust and RMR LLC. Other officers of RMR LLC and RMR Inc. also serve as officers of the Company. As of March 31, 2018 , we owned 2,637,408 shares of class A common stock of RMR Inc. See Note 5 for further information regarding our investment in RMR Inc. AIC. We, ABP Trust, Five Star and four other companies to which RMR LLC provides management services currently own AIC in equal amounts. We and the other AIC shareholders participate in a combined property insurance program arranged and reinsured in part by AIC. As of March 31, 2018 and December 31, 2017 , our investment in AIC had a carrying value of $8,136 and $8,185 , respectively. These amounts are included in other assets in our condensed consolidated balance sheets. We recognized income related to our investment in AIC, which is presented as equity in earnings of an investee in our condensed consolidated statements of comprehensive income. Our other comprehensive income includes our proportionate part of unrealized gains on securities which are owned by AIC related to our investment in AIC. For further information about these and other such relationships and certain other related person transactions, refer to our Annual Report.

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes We have elected to be taxed as a real estate investment trust, or REIT, under the Internal Revenue Code of 1986, as amended, and as such, are generally not subject to federal and most state income taxation on our operating income provided we distribute our taxable income to our shareholders and meet certain organization and operating requirements. We do, however, lease certain managed senior living communities to our wholly owned TRSs that, unlike most of our subsidiaries, file a separate consolidated federal corporate income tax return and are subject to federal and state income taxes. Our consolidated income tax provision includes the income tax provision related to the operations of our TRSs and certain state income taxes we incur despite our taxation as a REIT. During the three months ended March 31, 2018 and 2017 , we recognized income tax expense of $260 and $92 , respectively.

Weighted Average Common Shares

Weighted Average Common Shares	3 Months Ended
	Mar. 31, 2018
Earnings Per Share [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): Three Months Ended March 31, 2018 2017 Weighted average common shares for basic earnings per share 237,478 237,391 Effect of dilutive securities: unvested share awards 15 25 Weighted average common shares for diluted earnings per share 237,493 237,416

Recent Accounting Pronounceme20

Recent Accounting Pronouncements (Policies)	3 Months Ended
	Mar. 31, 2018
Accounting Changes and Error Corrections [Abstract]
Recent Accounting Pronouncements	Recent Accounting Pronouncements On January 1, 2018, we adopted FASB Accounting Standards Update, or ASU, No. 2014-09 (and related clarifying guidance issued by the FASB), Revenue From Contracts With Customers, 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. A substantial portion of our revenue consists of rental income from leasing arrangements, including leases with residents at properties leased to our taxable REIT subsidiaries, or TRSs, which is specifically excluded from ASU No. 2014-09. We have adopted ASU No. 2014-09 using the modified retrospective approach. The adoption of ASU No. 2014-09 did not have a material impact on the amount or timing of our revenue recognition in our condensed consolidated financial statements. On January 1, 2018, we adopted FASB 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. The implementation of ASU No. 2016-01 resulted in the reclassification of historical changes in the fair value of our available for sale equity securities of $86,572 from cumulative other comprehensive income to cumulative net income. Effective January 1, 2018, changes in the fair value of our equity securities are recorded through earnings in accordance with ASU No. 2016-01. On January 1, 2018, we adopted FASB ASU No. 2016-18, Restricted Cash , which requires companies to show the changes in the total of cash and cash equivalents and restricted cash and restricted cash equivalents in the statement of cash flows. ASU No. 2016-18 also requires a reconciliation of the totals in the statement of cash flows to the related captions in the balance sheet. As a result, amounts included in restricted cash in our condensed consolidated balance sheets are presented with cash and cash equivalents in our condensed consolidated statements of cash flows to the related captions in the condensed consolidated balance sheets. Restricted cash totaled $14,080 and $3,126 as of March 31, 2018 and 2017, respectively. The implementation of ASU No. 2016-18 resulted in a $703 decrease to net cash provided by operating activities for the three months ended March 31, 2017. The adoption of ASU No. 2016-18 did not change our balance sheet presentation. 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 condensed 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 the adoption of ASU No. 2016-13 will have in our consolidated financial statements. We currently expect to adopt the standard using the modified retrospective approach.

Real Estate Properties (Tables)

Real Estate Properties (Tables)	3 Months Ended
	Mar. 31, 2018
Real Estate [Abstract]
Schedule of real estate property acquisition	The table below represents the purchase price allocations (including net closing adjustments) of the senior living community acquisitions that closed during the three months ended March 31, 2018, as described above: Date Location Leased/Managed Number of Properties Units Cash Paid Plus Assumed Debt (1) Land Building and Improvements FF&E Acquired Real Estate Intangible Assets Assumed Debt Premium on Assumed Debt January 2018 Tennessee Managed 1 88 $ 19,868 $ 580 $ 14,884 $ 1,209 $ 3,195 $ — $ — February 2018 Arizona Managed 1 127 22,622 2,017 17,123 390 4,451 16,748 (1,359 ) 2 215 $ 42,490 $ 2,597 $ 32,007 $ 1,599 $ 7,646 $ 16,748 $ (1,359 ) (1) Cash paid plus assumed debt, if any, includes closing costs. The table below represents the purchase price allocations (including net closing adjustments) of the MOB acquisitions that closed during the three months ended March 31, 2018, as described above: Date Location Number of Properties Number of Buildings Square Feet (000’s) Cash Paid Plus Assumed Debt (1) Land Building and Improvements Acquired Real Estate Leases (2) Assumed Debt January 2018 3 States 3 3 400 $ 91,698 $ 16,873 $ 54,605 $ 20,220 $ — March 2018 Virginia 1 1 135 23,275 2,863 11,105 9,307 11,050 4 4 535 $ 114,973 $ 19,736 $ 65,710 $ 29,527 $ 11,050 (1) Cash paid plus assumed debt, if any, includes closing costs. (2) The weighted average amortization period for acquired real estate leases as of the acquisition dates was 5.8 years.

Fair Value of Assets and Liab22

Fair Value of Assets and Liabilities (Tables)	3 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Assets and liabilities recurring and nonrecurring measured at fair value	The table below presents certain of our assets measured at fair value at March 31, 2018 , 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 Active Markets for Significant Other Unobservable Identical Assets Observable Inputs Inputs Description Total (Level 1) (Level 2) (Level 3) Recurring Fair Value Measurements Assets: Investment in RMR Inc. (1) $ 184,487 $ 184,487 $ — $ — Investment in Five Star (2) $ 5,506 $ 5,506 $ — $ — (1) Our 2,637,408 shares of class A common stock of The RMR Group Inc., or RMR Inc., which are included in other assets in our condensed 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 $69,826 as of March 31, 2018 . During the three months ended March 31, 2018 , we recorded an unrealized gain of $28,088 to adjust the carrying value of our investment in RMR Inc. class A common shares to their fair value. (2) Our 4,235,000 common shares of Five Star, which are included in other assets in our condensed 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 $6,353 as of March 31, 2018 . During the three months ended March 31, 2018 , we recorded an unrealized loss of $847 to adjust the carrying value of our investment in Five Star common shares to their fair value.
Schedule of carrying value and fair value of the financial instruments	The fair values of these financial instruments approximated their carrying values in our condensed consolidated financial statements as of such dates, except as follows: As of March 31, 2018 As of December 31, 2017 Description Carrying Amount (1) Estimated Fair Value Carrying Amount (1) Estimated Fair Value Senior unsecured notes $ 2,213,811 $ 2,292,648 $ 1,725,662 $ 1,810,882 Secured debts (2) 817,834 793,815 794,710 783,353 $ 3,031,645 $ 3,086,463 $ 2,520,372 $ 2,594,235 (1) Includes unamortized debt issuance costs, premiums and discounts. (2) We assumed certain of these secured debts in connection with our acquisitions of certain properties. We recorded the assumed secured debts at estimated fair value on the date of assumption and we are amortizing the fair value adjustments, if any, to interest expense over their respective terms to adjust interest expense to the estimated market interest rates as of the date of assumption.

Segment Reporting (Tables)

Segment Reporting (Tables)	3 Months Ended
	Mar. 31, 2018
Segment Reporting [Abstract]
Schedule of segment reporting information	For the Three Months Ended March 31, 2018 Triple Net Leased Senior Living Communities Managed Senior Living Communities MOBs All Other Operations Consolidated Revenues: Rental income $ 67,975 $ — $ 101,151 $ 4,602 $ 173,728 Residents fees and services — 102,087 — — 102,087 Total revenues 67,975 102,087 101,151 4,602 275,815 Expenses: Property operating expenses — 77,205 30,938 — 108,143 Depreciation and amortization 20,195 14,811 34,385 948 70,339 General and administrative — — — 25,118 25,118 Acquisition and certain other transaction related costs — — — 20 20 Total expenses 20,195 92,016 65,323 26,086 203,620 Operating income (loss) 47,780 10,071 35,828 (21,484 ) 72,195 Dividend income — — — 659 659 Unrealized gains and losses on equity securities, net — — — 27,241 27,241 Interest and other income — — — 54 54 Interest expense (571 ) (1,327 ) (5,909 ) (35,745 ) (43,552 ) Loss on early extinguishment of debt — (130 ) — — (130 ) Income (loss) from continuing operations before income tax expense and equity in earnings of an investee 47,209 8,614 29,919 (29,275 ) 56,467 Income tax expense — — — (260 ) (260 ) Equity in earnings of an investee — — — 44 44 Income (loss) before gain on sale of properties 47,209 8,614 29,919 (29,491 ) 56,251 Gain on sale of properties 181,154 — — — 181,154 Net income (loss) 228,363 8,614 29,919 (29,491 ) 237,405 Net income attributable to noncontrolling interest — — (1,383 ) — (1,383 ) Net income (loss) attributable to common shareholders $ 228,363 $ 8,614 $ 28,536 $ (29,491 ) $ 236,022 As of March 31, 2018 Triple Net Leased Senior Living Communities Managed Senior Living Communities MOBs All Other Operations Consolidated Total assets $ 2,199,708 $ 1,313,777 $ 3,454,428 $ 416,151 $ 7,384,064 For the Three Months Ended March 31, 2017 Triple Net Leased Senior Living Communities Managed Senior Living Communities MOBs All Other Operations Consolidated Revenues: Rental income $ 67,252 $ — $ 94,646 $ 4,545 $ 166,443 Residents fees and services — 98,118 — — 98,118 Total revenues 67,252 98,118 94,646 4,545 264,561 Expenses: Property operating expenses — 73,880 27,177 — 101,057 Depreciation and amortization 20,334 20,215 31,678 948 73,175 General and administrative — — — 15,083 15,083 Acquisition and certain other transaction related costs — — — 292 292 Total expenses 20,334 94,095 58,855 16,323 189,607 Operating income (loss) 46,918 4,023 35,791 (11,778 ) 74,954 Dividend income — — — 659 659 Interest and other income — — — 120 120 Interest expense (5,339 ) (1,176 ) (6,321 ) (30,652 ) (43,488 ) Income (loss) from continuing operations before income tax expense and equity in earnings of an investee 41,579 2,847 29,470 (41,651 ) 32,245 Income tax expense — — — (92 ) (92 ) Equity in earnings of an investee — — — 128 128 Net income (loss) 41,579 2,847 29,470 (41,615 ) 32,281 Net income attributable to noncontrolling interest — — (126 ) — (126 ) Net income (loss) attributable to common shareholders $ 41,579 $ 2,847 $ 29,344 $ (41,615 ) $ 32,155 As of December 31, 2017 Triple Net Leased Senior Living Communities Managed Senior Living Communities MOBs All Other Operations Consolidated Total assets $ 2,251,756 $ 1,273,757 $ 3,367,485 $ 401,021 $ 7,294,019

Weighted Average Common Shares

Weighted Average Common Shares (Tables)	3 Months Ended
	Mar. 31, 2018
Earnings Per Share [Abstract]
Schedule of Weighted Average Number of 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): Three Months Ended March 31, 2018 2017 Weighted average common shares for basic earnings per share 237,478 237,391 Effect of dilutive securities: unvested share awards 15 25 Weighted average common shares for diluted earnings per share 237,493 237,416

Basis of Presentation (Details)

Basis of Presentation (Details) $ in Thousands	1 Months Ended
	Mar. 31, 2017buildingproperty	Mar. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of properties included in joint venture agreement | property	1
Number of buildings included in joint venture agreement | building	2
Variable interest entity, consolidated, carrying amount, assets		$ 1,091,281	$ 1,102,986
Variable interest entity, consolidated, carrying amount, liabilities		$ 718,559	$ 720,678

Recent Accounting Pronounceme26

Recent Accounting Pronouncements (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Jan. 01, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Restricted cash	$ 14,080	$ 3,126
Net cash provided by operating activities	$ (84,034)	(114,075)
AOCI Attributable to Parent | Accounting Standards Update 2016-01
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect from other comprehensive income to retained earnings			$ (86,572)
Retained Earnings | Accounting Standards Update 2016-01
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect from other comprehensive income to retained earnings			$ 86,572
Restatement Adjustment | Accounting Standards Update 2016-18
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net cash provided by operating activities		$ 703

Real Estate Properties (Details

Real Estate Properties (Details) $ in Thousands	1 Months Ended					2 Months Ended	3 Months Ended
	Mar. 31, 2018USD ($)ft²buildingcommunityproperty	Feb. 28, 2018USD ($)living_unitcommunityproperty	Jan. 31, 2018USD ($)ft²living_unitbuildingcommunityproperty	Dec. 31, 2017USD ($)stateliving_unitproperty	Nov. 30, 2017property	Feb. 28, 2018USD ($)living_unitproperty	Jun. 30, 2018USD ($)community	Mar. 31, 2018USD ($)ft²buildingcommunityproperty	Mar. 31, 2017USD ($)
Real Estate Properties
Number of properties owned | property	444							444
Number of buildings owned | building	470							470
Number of states in which properties are located | state				42
Assumed Debt								$ 27,798	$ 0
Impairment of assets								$ 0
Discontinued Operations, Held-for-sale
Real Estate Properties
Number of real estate properties held-for-sale | community	2							2
Real estate held-for-sale	$ 18,479							$ 18,479
Five Star | Senior Living Communities
Real Estate Properties
Number of properties | property					6
Five Star | Senior Living Communities | Alabama and Indiana
Real Estate Properties
Number of properties | property				2
Purchase price excluding closing costs				$ 39,457
Acquisition and certain other transaction related costs				$ 307
Number of acquired private pay independent living units | living_unit				229
Five Star | Senior Living Communities | Tennessee
Real Estate Properties
Number of properties | community			1
Purchase price excluding closing costs			$ 19,868
Acquisition and certain other transaction related costs			$ 201
Number of acquired private pay independent living units | living_unit			88
Five Star | Senior Living Communities | Arizona
Real Estate Properties
Number of properties | community		1
Purchase price excluding closing costs		$ 22,622
Acquisition and certain other transaction related costs		$ 372
Number of acquired private pay independent living units | living_unit		127
Assumed Debt		$ 16,748
Scenario, Forecast | Five Star | Senior Living Communities
Real Estate Properties
Number of properties | community							2
Purchase price excluding closing costs							$ 23,300
Assumed Debt							$ 16,800
Acquisition | MOBs
Real Estate Properties
Number of properties | property								4
Number of buildings acquired | building								4
Area of real estate properties (in square feet) | ft²	535,000							535,000
Assumed Debt								$ 11,050
Acquisition | MOBs | Kansas, Missouri And California
Real Estate Properties
Number of properties | property			3
Acquisition and certain other transaction related costs			$ 544
Number of buildings acquired | building			3
Area of real estate properties (in square feet) | ft²			400,000
Assumed Debt			$ 0
Acquisition | MOBs | Virginia
Real Estate Properties
Number of properties | property	1
Acquisition and certain other transaction related costs	$ 525
Number of buildings acquired | building	1
Area of real estate properties (in square feet) | ft²	135,000							135,000
Assumed Debt	$ 11,050
Acquisition | Five Star | Senior Living Communities
Real Estate Properties
Number of properties | property						2
Number of acquired private pay independent living units | living_unit						215
Assumed Debt						$ 16,748
Acquisition | Five Star | Senior Living Communities | Tennessee
Real Estate Properties
Number of properties | property			1
Assumed Debt			$ 0
Acquisition | Five Star | Senior Living Communities | Arizona
Real Estate Properties
Number of properties | property		1
Assumed Debt		$ 16,748

Real Estate Properties - Acquis

Real Estate Properties - Acquisitions (Details) $ in Thousands	1 Months Ended				2 Months Ended	3 Months Ended
	Mar. 31, 2018USD ($)ft²buildingproperty	Feb. 28, 2018USD ($)living_unitcommunityproperty	Jan. 31, 2018USD ($)ft²living_unitbuildingcommunityproperty	Nov. 30, 2017property	Feb. 28, 2018USD ($)living_unitproperty	Mar. 31, 2018USD ($)ft²buildingproperty	Mar. 31, 2017USD ($)
Real Estate Properties
Assumed Debt						$ 27,798	$ 0
Acquisition | MOBs
Real Estate Properties
Number of properties | property						4
Number of buildings acquired | building						4
Area of real estate properties (in square feet) | ft²	535,000					535,000
Cash Paid plus Assumed Debt						$ 114,973
Acquired Real Estate Intangible Assets	$ 29,527					29,527
Assumed Debt						$ 11,050
Acquisition | Kansas, Missouri And California | MOBs
Real Estate Properties
Number of properties | property			3
Number of buildings acquired | building			3
Area of real estate properties (in square feet) | ft²			400,000
Cash Paid plus Assumed Debt			$ 91,698
Acquired Real Estate Intangible Assets			20,220
Assumed Debt			0
Acquisition | Virginia | MOBs
Real Estate Properties
Number of properties | property	1
Number of buildings acquired | building	1
Area of real estate properties (in square feet) | ft²	135,000					135,000
Cash Paid plus Assumed Debt	$ 23,275
Acquired Real Estate Intangible Assets	9,307					$ 9,307
Assumed Debt	11,050
Acquisition | Land | MOBs
Real Estate Properties
Real estate properties acquired, property plant and equipment						19,736
Acquisition | Land | Kansas, Missouri And California | MOBs
Real Estate Properties
Real estate properties acquired, property plant and equipment			16,873
Acquisition | Land | Virginia | MOBs
Real Estate Properties
Real estate properties acquired, property plant and equipment	2,863
Acquisition | Building and Improvements | MOBs
Real Estate Properties
Real estate properties acquired, property plant and equipment						$ 65,710
Acquisition | Building and Improvements | Kansas, Missouri And California | MOBs
Real Estate Properties
Real estate properties acquired, property plant and equipment			$ 54,605
Acquisition | Building and Improvements | Virginia | MOBs
Real Estate Properties
Real estate properties acquired, property plant and equipment	$ 11,105
Five Star | Senior Living Communities
Real Estate Properties
Number of properties | property				6
Five Star | Tennessee | Senior Living Communities
Real Estate Properties
Number of properties | community			1
Number of acquired private pay independent living units | living_unit			88
Five Star | Arizona | Senior Living Communities
Real Estate Properties
Number of properties | community		1
Number of acquired private pay independent living units | living_unit		127
Assumed Debt		$ 16,748
Five Star | Acquisition | Senior Living Communities
Real Estate Properties
Number of properties | property					2
Number of acquired private pay independent living units | living_unit					215
Cash Paid plus Assumed Debt					$ 42,490
Acquired Real Estate Intangible Assets		$ 7,646			7,646
Assumed Debt					16,748
Premium on Assumed Debt					(1,359)
Five Star | Acquisition | Tennessee | Senior Living Communities
Real Estate Properties
Number of properties | property			1
Cash Paid plus Assumed Debt			$ 19,868
Acquired Real Estate Intangible Assets			3,195
Assumed Debt			0
Premium on Assumed Debt			0
Five Star | Acquisition | Arizona | Senior Living Communities
Real Estate Properties
Number of properties | property		1
Cash Paid plus Assumed Debt		$ 22,622
Acquired Real Estate Intangible Assets		4,451			4,451
Assumed Debt		16,748
Premium on Assumed Debt		(1,359)
Five Star | Acquisition | Land | Senior Living Communities
Real Estate Properties
Real estate properties acquired, property plant and equipment					2,597
Five Star | Acquisition | Land | Tennessee | Senior Living Communities
Real Estate Properties
Real estate properties acquired, property plant and equipment			580
Five Star | Acquisition | Land | Arizona | Senior Living Communities
Real Estate Properties
Real estate properties acquired, property plant and equipment		2,017
Five Star | Acquisition | Building and Improvements | Senior Living Communities
Real Estate Properties
Real estate properties acquired, property plant and equipment					32,007
Five Star | Acquisition | Building and Improvements | Tennessee | Senior Living Communities
Real Estate Properties
Real estate properties acquired, property plant and equipment			14,884
Five Star | Acquisition | Building and Improvements | Arizona | Senior Living Communities
Real Estate Properties
Real estate properties acquired, property plant and equipment		17,123
Five Star | Acquisition | FF&E | Senior Living Communities
Real Estate Properties
Real estate properties acquired, property plant and equipment					$ 1,599
Five Star | Acquisition | FF&E | Tennessee | Senior Living Communities
Real Estate Properties
Real estate properties acquired, property plant and equipment			$ 1,209
Five Star | Acquisition | FF&E | Arizona | Senior Living Communities
Real Estate Properties
Real estate properties acquired, property plant and equipment		$ 390
Lease Agreements | Acquisition | MOBs
Real Estate Properties
Weighted average amortization period						5 years 9 months 18 days

Real Estate Properties - Leases

Real Estate Properties - Leases (Details) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2018USD ($)	Mar. 31, 2017USD ($)	Dec. 31, 2017USD ($)community	Jan. 31, 2018tenant
Real Estate [Line Items]
Straight line rent	$ 2,993	$ 3,429
Senior Living Communities
Real Estate [Line Items]
Number of communities leased by the Company | community			8
Pacifica Senior Living, LLC. | Senior Living Communities
Real Estate [Line Items]
Lease deposit			$ 3,277
Number of tenants | tenant				1
Proceeds from rents received			2,049
Straight line rent			105
Security deposit liability			$ 583
Period of guaranteed rent			1 year
Rental income, security deposit applied	$ 528

Real Estate Properties - Dispos

Real Estate Properties - Dispositions (Details) $ in Thousands	1 Months Ended	3 Months Ended
	Mar. 31, 2018USD ($)community	Mar. 31, 2018USD ($)	Mar. 31, 2017USD ($)	Mar. 31, 2018nursing_facility	Mar. 31, 2018community
Real Estate [Line Items]
Proceeds from sale of properties		$ 216,013	$ 0
Gain on sale of properties		181,154	$ 0
Skilled Nursing Facility
Real Estate [Line Items]
Number of real estate properties held-for-sale				1	2
Real estate, held-for-sale, aggregate sales price	$ 6,500	6,500
Real estate held-for-sale	18,479	18,479
Sunrise Senior Living LLC | Senior Living Communities
Real Estate [Line Items]
Number of real estate properties held-for-sale | community					3
Real estate, held-for-sale, aggregate sales price	$ 96,000	96,000
Rental income recognized		2,776
Sunrise Senior Living LLC | Senior Living Communities | Disposal Group, Disposed of by Sale, Not Discontinued Operations
Real Estate [Line Items]
Number of communities sold | community	2
Proceeds from sale of properties		217,000
Gain on sale of properties		$ 181,154

Indebtedness (Details)

Indebtedness (Details) $ in Thousands	1 Months Ended	3 Months Ended
	Feb. 28, 2018USD ($)	Mar. 31, 2018USD ($)propertybuildingnote	Mar. 31, 2017USD ($)	May 09, 2018USD ($)	Dec. 31, 2017USD ($)
Indebtedness
Number of public issues of unsecured senior notes | note		7
Total real estate properties, gross		$ 7,958,274			$ 7,824,763
Unsecured revolving credit facility		55,000			$ 596,000
Unsecured revolving credit facility
Indebtedness
Unsecured revolving credit facility, maximum borrowing capacity		1,000,000
Line of credit facility, periodic payment, principal		$ 0
Revolving credit facility, interest rate payable (as a percent)		2.90%
Weighted average interest rate on debt (as a percent)		2.70%	2.10%
Unsecured revolving credit facility		$ 55,000
Revolving credit facility, available amount		945,000
Interest expense and other associated costs incurred		4,077	$ 2,830
Option to increase the borrowing capacity under revolving credit facility		$ 2,000,000
Unsecured revolving credit facility | LIBOR
Indebtedness
Interest rate added to the base rate (as a percent)		1.20%
Debt instrument, facility fee (as a percent)		0.25%
Unsecured revolving credit facility | Subsequent Event
Indebtedness
Unsecured revolving credit facility				$ 35,000
Revolving credit facility, available amount				$ 965,000
Senior unsecured notes due 2019
Indebtedness
Debt face amount		$ 400,000
Interest rate (as a percent)		3.25%
Senior unsecured notes due 2020
Indebtedness
Debt face amount		$ 200,000
Interest rate (as a percent)		6.75%
Senior unsecured notes due 2021
Indebtedness
Debt face amount		$ 300,000
Interest rate (as a percent)		6.75%
Senior unsecured notes due 2024
Indebtedness
Debt face amount		$ 250,000
Interest rate (as a percent)		4.75%
Senior unsecured notes due 2028
Indebtedness
Debt face amount		$ 500,000
Interest rate (as a percent)	4.75%	4.75%
Proceeds from debt, net of issuance costs	$ 487,264
Proceeds from issuance of debt	$ 500,000
Senior unsecured notes due 2042
Indebtedness
Debt face amount		$ 350,000
Interest rate (as a percent)		5.625%
Senior unsecured notes due 2046
Indebtedness
Debt face amount		$ 250,000
Interest rate (as a percent)		6.25%
Term loan due 2020
Indebtedness
Debt face amount		$ 350,000
Interest rate (as a percent)		3.10%
Weighted average interest rate on debt (as a percent)		3.10%	2.20%
Interest expense and other associated costs incurred		$ 2,766	$ 2,043
Maximum borrowing capacity that may be increased		$ 700,000
Term loan due 2020 | LIBOR
Indebtedness
Interest rate added to the base rate (as a percent)		1.40%
Term loan due 2022
Indebtedness
Debt face amount		$ 200,000
Interest rate (as a percent)		3.20%
Weighted average interest rate on debt (as a percent)		3.00%	2.60%
Interest expense and other associated costs incurred		$ 1,564	$ 1,359
Maximum borrowing capacity that may be increased		$ 400,000
Term loan due 2022 | LIBOR
Indebtedness
Interest rate added to the base rate (as a percent)		1.35%
Mortgages
Indebtedness
Aggregate principal amount of mortgage debt		$ 818,457
Number of properties mortgaged | property		24
Number of buildings mortgaged | building		25
Total real estate properties, gross		$ 1,245,304
Capital leases
Indebtedness
Total real estate properties, gross		$ 36,238
Number of properties recorded under capital lease | property		2
Capital leases		$ 10,484

Fair Value of Assets and Liab32

Fair Value of Assets and Liabilities - Assets (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Recurring Fair Value Measurements
Unrealized gains and losses on equity securities, net	$ 27,241	$ 0
Five Star
Recurring Fair Value Measurements
Equity securities investment (in shares)	4,235,000
Recurring | RMR Inc
Recurring Fair Value Measurements
Investments in affiliates, fair value	$ 184,487
Recurring | Five Star
Recurring Fair Value Measurements
Investments in affiliates, fair value	5,506
Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | RMR Inc
Recurring Fair Value Measurements
Investments in affiliates, fair value	184,487
Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Five Star
Recurring Fair Value Measurements
Investments in affiliates, fair value	5,506
Recurring | Significant Other Observable Inputs (Level 2) | RMR Inc
Recurring Fair Value Measurements
Investments in affiliates, fair value	0
Recurring | Significant Other Observable Inputs (Level 2) | Five Star
Recurring Fair Value Measurements
Investments in affiliates, fair value	0
Recurring | Significant Unobservable Inputs (Level 3) | RMR Inc
Recurring Fair Value Measurements
Investments in affiliates, fair value	0
Recurring | Significant Unobservable Inputs (Level 3) | Five Star
Recurring Fair Value Measurements
Investments in affiliates, fair value	$ 0
Class A common shares | RMR Inc
Recurring Fair Value Measurements
Equity securities investment (in shares)	2,637,408
Investment, original cost	$ 69,826
Unrealized gains and losses on equity securities, net	28,088
Common Shares
Recurring Fair Value Measurements
Investment, original cost	6,353
Unrealized gains and losses on equity securities, net	$ (847)
Common Shares | Five Star
Recurring Fair Value Measurements
Equity securities investment (in shares)	4,235,000

Fair Value of Assets and Liab33

Fair Value of Assets and Liabilities - Liabilities (Details) $ in Thousands	Mar. 31, 2018USD ($)debt_security	Dec. 31, 2017USD ($)
Liabilities:
Senior unsecured notes	$ 2,213,811	$ 1,725,662
Carrying Amount
Liabilities:
Senior unsecured notes	2,213,811	1,725,662
Secured debt	817,834	794,710
Debt instrument	3,031,645	2,520,372
Estimated Fair Value
Liabilities:
Senior unsecured notes	2,292,648	1,810,882
Secured debt	793,815	783,353
Debt instrument	$ 3,086,463	$ 2,594,235
Quoted Prices in Active Markets for Identical Assets (Level 1)
Liabilities:
Fair value measurement, number of debt securities | debt_security	2
Significant Other Observable Inputs (Level 2)
Liabilities:
Fair value measurement, number of debt securities | debt_security	5

Noncontrolling Interest (Detail

Noncontrolling Interest (Details) $ in Thousands	1 Months Ended	3 Months Ended
	Mar. 31, 2017USD ($)buildingproperty	Mar. 31, 2018USD ($)	Mar. 31, 2017USD ($)
Noncontrolling Interest [Line Items]
Number of properties included in joint venture agreement | property	1
Number of buildings included in joint venture agreement | building	2
Noncontrolling interest, ownership percentage by noncontrolling owners	45.00%		45.00%
Noncontrolling interest, ownership percentage by parent	55.00%		55.00%
Proceeds from noncontrolling interest, net	$ 255,931	$ 0	$ 255,813
Noncontrolling interest in variable interest equity	181,859		181,859
Adjustments to additional paid in capital, difference between net proceeds received and fair value of noncontrolling interest equity	74,072
Comprehensive income attributable to noncontrolling interest		(1,383)	(126)
Cash distribution for joint venture partners		5,667	$ 0
Variable interest entity, consolidated, carrying amount, real estate assets		759,654
Variable interest entity, consolidated, carrying amount, mortgage debt		$ 620,000
Third Party Investor
Noncontrolling Interest [Line Items]
Noncontrolling interest, increase from business combination	$ 261,009

Shareholders' Equity (Details)

Shareholders' Equity (Details) - $ / shares	Mar. 29, 2018	Jan. 01, 2018	Dec. 29, 2017
Former Employees Of RMR LLC
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares purchased to satisfy tax withholding and payment obligations (in shares)		4,628
Shares purchased to satisfy tax withholding and payment obligations, price per share (in dollars per share)			$ 19.15
Trustees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation, shares issued in period (in shares)	3,000
Share-based compensation, equity instruments other than options, nonvested closing price	$ 15.66

Shareholder's Equity - Distribu

Shareholder's Equity - Distribution to Common Shareholders (Details) - USD ($) $ / shares in Units, $ in Thousands	May 17, 2018	Apr. 19, 2018	Feb. 22, 2018	Jan. 19, 2018	Mar. 31, 2018	Mar. 31, 2017
Subsequent Event [Line Items]
Distribution to common shareholders (in dollars per share)			$ 0.39
Distribution to common shareholders			$ 92,674		$ 92,674	$ 92,642
Distributions to common shareholders declared (in dollars per share)				$ 0.39
Distribution payable				$ 92,674
Subsequent Event
Subsequent Event [Line Items]
Distributions to common shareholders declared (in dollars per share)		$ 0.39
Distribution payable		$ 92,675
Scenario, Forecast
Subsequent Event [Line Items]
Distribution to common shareholders (in dollars per share)	$ 0.39
Distribution to common shareholders	$ 92,675

Segment Reporting (Details)

Segment Reporting (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018USD ($)segment	Mar. 31, 2017USD ($)	Dec. 31, 2017USD ($)
Segment Reporting [Abstract]
Number of operating segments | segment	4
Number of reportable segments | segment	3
Revenues:
Rental income	$ 173,728	$ 166,443
Residents fees and services	102,087	98,118
Total revenues	275,815	264,561
Expenses:
Property operating expenses	108,143	101,057
Depreciation and amortization	70,339	73,175
General and administrative	25,118	15,083
Acquisition and certain other transaction related costs	20	292
Total expenses	203,620	189,607
Operating income	72,195	74,954
Dividend income	659	659
Unrealized gains and losses on equity securities, net	27,241	0
Interest and other income	54	120
Interest expense	(43,552)	(43,488)
Loss on early extinguishment of debt	(130)	0
Income from continuing operations before income tax expense and equity in earnings of an investee	56,467	32,245
Income (loss) from continuing operations	237,405	32,281
Income tax expense	(260)	(92)
Equity in earnings of an investee	44	128
Income (loss) before gain on sale of properties	56,251	32,281
Gain on sale of properties	181,154	0
Net income (loss)	237,405	32,281
Net income attributable to noncontrolling interest	(1,383)	(126)
Net income attributable to common shareholders	236,022	32,155
Total assets	7,384,064		$ 7,294,019
Triple Net Leased Senior Living Communities
Revenues:
Rental income	67,975	67,252
Residents fees and services	0	0
Total revenues	67,975	67,252
Expenses:
Property operating expenses	0	0
Depreciation and amortization	20,195	20,334
General and administrative	0	0
Acquisition and certain other transaction related costs	0	0
Total expenses	20,195	20,334
Operating income	47,780	46,918
Dividend income	0	0
Unrealized gains and losses on equity securities, net	0
Interest and other income	0	0
Interest expense	(571)	(5,339)
Loss on early extinguishment of debt	0
Income from continuing operations before income tax expense and equity in earnings of an investee	47,209	41,579
Income (loss) from continuing operations		41,579
Income tax expense	0	0
Equity in earnings of an investee	0	0
Income (loss) before gain on sale of properties	47,209	41,579
Gain on sale of properties	181,154	0
Net income (loss)	228,363	41,579
Net income attributable to noncontrolling interest	0	0
Net income attributable to common shareholders	228,363	41,579
Total assets	2,199,708		2,251,756
Managed Senior Living Communities
Revenues:
Rental income	0	0
Residents fees and services	102,087	98,118
Total revenues	102,087	98,118
Expenses:
Property operating expenses	77,205	73,880
Depreciation and amortization	14,811	20,215
General and administrative	0	0
Acquisition and certain other transaction related costs	0	0
Total expenses	92,016	94,095
Operating income	10,071	4,023
Dividend income	0	0
Unrealized gains and losses on equity securities, net	0
Interest and other income	0	0
Interest expense	(1,327)	(1,176)
Loss on early extinguishment of debt	(130)
Income from continuing operations before income tax expense and equity in earnings of an investee	8,614	2,847
Income (loss) from continuing operations		2,847
Income tax expense	0	0
Equity in earnings of an investee	0	0
Income (loss) before gain on sale of properties	8,614	2,847
Gain on sale of properties	0	0
Net income (loss)	8,614	2,847
Net income attributable to noncontrolling interest	0	0
Net income attributable to common shareholders	8,614	2,847
Total assets	1,313,777		1,273,757
MOBs
Revenues:
Rental income	101,151	94,646
Residents fees and services	0	0
Total revenues	101,151	94,646
Expenses:
Property operating expenses	30,938	27,177
Depreciation and amortization	34,385	31,678
General and administrative	0	0
Acquisition and certain other transaction related costs	0	0
Total expenses	65,323	58,855
Operating income	35,828	35,791
Dividend income	0	0
Unrealized gains and losses on equity securities, net	0
Interest and other income	0	0
Interest expense	(5,909)	(6,321)
Loss on early extinguishment of debt	0
Income from continuing operations before income tax expense and equity in earnings of an investee	29,919	29,470
Income (loss) from continuing operations		29,470
Income tax expense	0	0
Equity in earnings of an investee	0	0
Income (loss) before gain on sale of properties	29,919	29,470
Gain on sale of properties	0	0
Net income (loss)	29,919	29,470
Net income attributable to noncontrolling interest	(1,383)	(126)
Net income attributable to common shareholders	28,536	29,344
Total assets	3,454,428		3,367,485
All Other Operations
Revenues:
Rental income	4,602	4,545
Residents fees and services	0	0
Total revenues	4,602	4,545
Expenses:
Property operating expenses	0	0
Depreciation and amortization	948	948
General and administrative	25,118	15,083
Acquisition and certain other transaction related costs	20	292
Total expenses	26,086	16,323
Operating income	(21,484)	(11,778)
Dividend income	659	659
Unrealized gains and losses on equity securities, net	27,241
Interest and other income	54	120
Interest expense	(35,745)	(30,652)
Loss on early extinguishment of debt	0
Income from continuing operations before income tax expense and equity in earnings of an investee	(29,275)	(41,651)
Income (loss) from continuing operations		(41,615)
Income tax expense	(260)	(92)
Equity in earnings of an investee	44	128
Income (loss) before gain on sale of properties	(29,491)	(41,615)
Gain on sale of properties	0	0
Net income (loss)	(29,491)	(41,615)
Net income attributable to noncontrolling interest	0	0
Net income attributable to common shareholders	(29,491)	$ (41,615)
Total assets	$ 416,151		$ 401,021

Leases and Management Agreeme38

Leases and Management Agreements with Five Star (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018USD ($)lease_agreementcommunity	Mar. 31, 2017USD ($)community	Dec. 31, 2017USD ($)community
Senior Living Communities
Number of communities leased by the Company | community			8
Five Star
Number of communities leased by the Company | community	185	185
Number of leases with related party | lease_agreement	5
Total rental income recognized	$ 51,759	$ 50,985
Related party transaction, annual rents due	1,374	1,445
Rents receivable	17,265		$ 18,539
Real estate improvements purchased		8,082
Increase or decrease in annual lease rent payable		648
Property management agreement expense	$ 3,494	$ 3,299
Five Star | Rents from significant lessee | Revenues
% of Total (as a percent)	18.80%
Five Star | Rents from significant lessee | Investment
% of Total (as a percent)	27.00%
Five Star | Senior Living Communities
Number of communities managed by related party | community	72	68
Rehabilitation Services | Five Star
Expenses from transactions with related party	$ 1,699	$ 1,982

Business and Property Managem39

Business and Property Management Agreements with RMR LLC (Details) $ in Thousands	1 Months Ended	3 Months Ended
	Jan. 31, 2018USD ($)	Mar. 31, 2018USD ($)management_agreementemployeeproperty	Mar. 31, 2017USD ($)
Related person transactions
Number of employees | employee		0
Related party transaction business management agreement incentive fee paid	$ 55,740
Property management and construction supervision fees		$ 2,821	$ 2,590
Property management and construction supervision fees paid		2,779	2,379
Professional fees		69	67
RMR LLC
Related person transactions
Business management fees incurred		23,323	12,781
Related party transaction business management fees related to subsidiary level management		725	62
Related party transaction business management agreement, annual incentive fee estimate included in management fees		$ 14,347	$ 3,266
Related party transaction, incentive fee payable assessment period		3 years
Senior Living Communities | RMR Inc
Related person transactions
Number of consecutive renewal terms of agreement | management_agreement		2
Number of communities managed by related party | property		1

Related Person Transactions - F

Related Person Transactions - Five Star (Details) - Five Star	Mar. 31, 2018shares
Related person transactions
Equity securities investment (in shares)	4,235,000
Investment owned, percentage of total shares outstanding	8.40%
RMR LLC
Related person transactions
Investment owned, percentage of total shares outstanding	35.60%

Related Person Transactions - I

Related Person Transactions - Investment in RMR Inc (Details) $ in Thousands	Mar. 31, 2018USD ($)agreementshares	Dec. 31, 2017USD ($)
RMR Inc | Class A common shares
Related person transactions
Number of management agreements | agreement	2
Equity securities investment (in shares)	2,637,408
Five Star
Related person transactions
Equity securities investment (in shares)	4,235,000
AIC
Related person transactions
Equity method investments | $	$ 8,136	$ 8,185

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Components of provision for income taxes
Income tax expense (benefit)	$ 260	$ 92

Weighted Average Common Share43

Weighted Average Common Shares (Details) - shares shares in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Earnings Per Share [Abstract]
Weighted average common shares for basic earnings per share	237,478	237,391
Effect of dilutive securities: unvested share awards	15	25
Weighted average common shares for diluted earnings per share	237,493	237,416