Summary of Significant Accounting Policies (Policies)	12 Months Ended
Dec. 31, 2012
Summary of Significant Accounting Policies
BASIS OF PRESENTATION	BASIS OF PRESENTATION. Our consolidated financial statements include the accounts of Senior Housing Properties Trust, or we, us or our, and our subsidiaries, all of which are 100% owned directly or indirectly by us. All intercompany transactions and balances have been eliminated.
REAL ESTATE PROPERTIES	REAL ESTATE PROPERTIES. We depreciate real estate properties on a straight line basis over estimated useful lives of up to 40 years for buildings and improvements and up to 12 years for personal property. Our management regularly evaluates whether events or changes in circumstances have occurred that could indicate an impairment in the value of long lived assets. If there is an indication that the carrying value of an asset is not recoverable, we estimate the projected undiscounted cash flows to determine if an impairment loss should be recognized. We determine the amount of any impairment loss by comparing the historical carrying value to estimated fair value. We estimate fair value through an evaluation of recent financial performance and projected discounted cash flows using standard industry valuation techniques. In addition to consideration of impairment upon the events or changes in circumstances described above, we regularly evaluate the remaining lives of our long lived assets. If we change our estimate of the remaining lives, we allocate the carrying value of the affected assets over their revised remaining lives. We allocate the consideration paid, generally cash plus the fair value of any assumed liabilities, for our properties among land, building and improvements and identified intangible assets and liabilities, consisting of the value of above market and below market leases, the value of in place leases and the value of tenant relationships. Purchase price allocations and the determination of useful lives are based on our estimates and, under some circumstances studies from independent real estate appraisal firms to provide market information and evaluations that are relevant to our purchase price allocations and determinations of useful lives; however, we are ultimately responsible for the purchase price allocations and determination of useful lives. We allocate the consideration to land, building and improvements based on a determination of the fair values of these assets assuming the property is vacant. We determine the fair value of a property using methods that we believe are similar to those used by independent appraisers. Purchase price allocations to above market and below market leases are based on the estimated present value (using an interest rate which reflects our assessment of the risks associated with the leases acquired) of the difference between (i) the contractual amounts to be paid pursuant to the in place leases and (ii) our estimate of fair market lease rates for the corresponding leases, measured over a period equal to the remaining non-cancelable terms of the respective leases. Purchase price allocations to in place leases and tenant relationships are determined as the excess of (i) the purchase price paid for a property after adjusting existing in place leases to estimated market rental rates over (ii) the estimated fair value of the property as if vacant. We aggregate this value between in place lease values and tenant relationships based on our evaluation of the specific characteristics of each tenant's lease; however, the value of tenant relationships has not been separated from in place lease value for our properties because we believe such value and related amortization expense is immaterial for acquisitions reflected in our historical financial statements. We consider certain factors in performing these analyses including estimates of carrying costs during the expected lease up periods, including real estate taxes, insurance and other operating income and expenses and costs to execute similar leases in current market conditions, such as leasing commissions, legal and other related costs. If we believe the value of tenant relationships are material in the future, those amounts will be separately allocated and amortized over the estimated lives of the relationships. We recognize the excess, if any, of the consideration paid over amounts allocated to land, buildings and improvements and identified intangible assets and liabilities as goodwill. We amortize capitalized above market lease values (included in acquired real estate leases in our consolidated balance sheets) as a reduction to rental income over the remaining non-cancelable terms of the respective leases. We amortize capitalized below market lease values (presented as acquired real estate lease obligations in our consolidated balance sheets) as an increase to rental income over the non-cancelable periods of the respective leases. We amortize the value of in place leases exclusive of the value of above market and below market in place leases to expense over the remaining non-cancelable periods of the respective leases. If a lease is terminated prior to its stated expiration, the unamortized amount relating to that lease is written off.
CASH AND CASH EQUIVALENTS	CASH AND CASH EQUIVALENTS. We carry cash and cash equivalents, consisting of overnight repurchase agreements and short term investments with original maturities of three months or less at the date of purchase, at cost plus accrued interest, which approximates fair value.
RESTRICTED CASH	RESTRICTED CASH. Restricted cash consists of amounts escrowed for real estate taxes, insurance and capital expenditures at certain of our mortgaged properties.
INVESTMENTS IN AVAILABLE FOR SALE SECURITIES	INVESTMENTS IN AVAILABLE FOR SALE SECURITIES. We own 250,000 common shares, or 0.3% at December 31, 2012, of CommonWealth REIT, or CWH. We also own 4,235,000 common shares, or 8.8% at December 31, 2012, of Five Star Quality Care, Inc., or Five Star. We classify these holdings as available for sale and carry them at fair value, with unrealized gains and losses reported as a separate component of shareholders' equity. Cumulative other comprehensive income shown in our consolidated balance sheets includes the net unrealized gain or loss on investments determined as the net difference between the market value of these shares of CWH and Five Star calculated by using weighted average quoted market prices on the dates we acquired these shares ($26.00 and $3.36 per share, respectively) and on December 31, 2012 ($15.84 and $5.01 per share, respectively). At December 31, 2012 and 2011, our investment in CWH had a fair value of $3,960 and $4,160, respectively, including an unrealized loss of $2,540 and $2,340, respectively. At December 31, 2012 and 2011, our investment in Five Star had a fair value of $21,217 and $12,705, respectively, including an unrealized gain (loss) of $7,003 and $(1,509), respectively.
EQUITY METHOD INVESTMENTS	EQUITY METHOD INVESTMENTS. We and the other seven current shareholders each currently own 12.5% of Affiliates Insurance Company, or AIC's, outstanding equity. Although we own less than 20% of AIC, we use the equity method to account for this investment because we believe that we have significant influence over AIC because all of our Trustees are also directors of AIC. Under the equity method, we record our percentage share of net earnings from AIC in our consolidated statements of income and comprehensive income. If we determine there is an "other than temporary impairment" in the fair value of this investment, we would record a charge to earnings. In evaluating the fair value of this investment, we have considered, among other things, the assets and liabilities held by AIC, AIC's overall financial condition and earning trends, and the financial condition and prospects for the insurance industry generally. See Note 5 for a further discussion of our investment in AIC.
DEFERRED FINANCING FEES	DEFERRED FINANCING FEES. We capitalize issuance costs related to borrowings and amortize them over the terms of the respective loans. During 2012, we capitalized $12,608 of issuance costs, including $11,439 related to our $350,000 senior notes issued in July 2012, $1,125 related to our assumption of mortgage loans during 2012 and $44 related to our $300,000 senior notes issued in December 2011. During 2011, we capitalized $13,760 of issuance costs, including $6,723 related to refinancing our revolving credit facility in June 2011, $2,540 related to our assumption of mortgage loans during 2011, $2,487 related to our $300,000 senior notes issued in December 2011, $1,973 related to our $250,000 senior notes issued in January 2011 and $37 related to our $512,934 Federal National Mortgage Association, or FNMA, mortgage financing we closed in August 2009. During 2010, we capitalized $4,661 of issuance costs, including $2,907 related to our $200,000 senior notes issued in April 2010, $903 related to our $512,934 FNMA mortgage financing we closed in August 2009, $826 related to our one year extension to December 31, 2011 on our $550,000 revolving credit facility and $25 related to our assumption of a mortgage loan in April 2010. During 2012, we wrote off $3,897 of unamortized deferred financing fees in connection with our prepayment of approximately $199,197 of the outstanding principal balance of our $512,934 FNMA mortgage financing we closed in August 2009. During 2011, we wrote off $427 of unamortized deferred financing fees in connection with the refinancing of our revolving credit facility. During 2010, we wrote off $1,153 of deferred financing fees and unamortized discounts in connection with the retirement of all of our 7.875% senior notes. The unamortized gross balance of deferred financing fees and related accumulated amortization was $39,471 and $10,061, and $36,144 and $10,710 at December 31, 2012 and 2011, respectively. The weighted average amortization period is approximately 14.7 years. We expect that the amortization expense for the five years subsequent to December 31, 2012 will be $4,748 in 2013, $4,695 in 2014, $3,621 in 2015, $2,170 in 2016, $1,861 in 2017 and $12,315, thereafter.
DEFERRED LEASING COSTS	DEFERRED LEASING COSTS. Deferred leasing costs include brokerage, legal and other fees associated with the successful negotiation of leases and are amortized on a straight line basis over the terms of the respective leases. Deferred leasing costs are included in other assets on our consolidated balance sheets. The unamortized gross balance of deferred leasing costs and related accumulated amortization was $6,917 and $1,793, and $4,663 and $902 at December 31, 2012 and 2011, respectively. The weighted average amortization period is approximately 6.4 years. We expect that the amortization expense for the five years subsequent to December 31, 2012 will be $1,017 in 2013, $946 in 2014, $843 in 2015, $674 in 2016, $530 in 2017 and $1,114, thereafter.
LOANS RECEIVABLE	LOANS RECEIVABLE. Loans receivable are stated at the unpaid principal balance. We recognized interest income based on the contractual terms in the loan agreement, which is included in interest and other income on our consolidated statements of income and comprehensive income.
ALLOWANCE FOR DOUBTFUL ACCOUNTS	ALLOWANCE FOR DOUBTFUL ACCOUNTS. We maintain an allowance for doubtful accounts for estimated losses resulting from the inability or unwillingness of certain tenants to make payments required under their leases. The computation of the allowance is based on the tenants' payment histories and current credit profiles, as well as other considerations. The net amount of our accounts receivables from third parties appear in other assets on our consolidated balance sheets.
REVENUE RECOGNITION	REVENUE RECOGNITION. We recognize rental income from operating leases on a straight line basis over the term of each lease agreement. We recognize percentage rents when realizable and earned, which is generally during the fourth quarter of the year. For the years ended December 31, 2012, 2011 and 2010, percentage rents earned aggregated $10,859, $11,313, and $10,315, respectively. As of December 31, 2012, we own 39 senior living communities, including 29 communities that we acquired since June 2011 and the 10 senior living communities, or the 10 Communities, formerly leased to Sunrise Senior Living, Inc., or Sunrise, that are managed by Five Star. We refer to these 39 communities as the Managed Communities. We derive our revenues at these Managed Communities primarily from services to residents and we record revenues when services are provided. Our share of the net operating results of our Managed Communities in excess of the minimum returns due to us, or additional returns, are generally determined annually. We recognize additional returns due to us under our management agreements at year end when all contingencies are met and the income is earned. We had no additional returns in 2012 and 2011.
EARNINGS PER COMMON SHARE	EARNINGS PER COMMON SHARE. We compute earnings per common share using the weighted average number of shares outstanding during the period. We have no common share equivalents, instruments convertible into common shares or other dilutive instruments.
USE OF ESTIMATES	USE OF ESTIMATES. Accounting principles generally accepted in the United States requires us to make estimates and assumptions that may affect the amounts reported in these financial statements and related notes. The actual results could differ from these estimates.
INCOME TAXES	INCOME TAXES. We have elected to be taxed as a 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 our Managed Communities to our wholly owned taxable REIT subsidiaries, or TRSs, that, unlike most of our subsidiaries, files a separate tax return and are subject to federal and state income tax. Our consolidated income tax provision includes the income tax provision related to the operations of our TRSs and certain state income taxes incurred by us, despite our REIT status. The Income Taxes Topic of the Codification prescribes how we should recognize, measure and present in our financial statements uncertain tax positions that have been taken or are expected to be taken in a tax return. Deferred tax benefits are recognized to the extent that it is "more likely than not" that a particular tax position will be sustained upon examination or audit. To the extent the "more likely than not" standard has been satisfied, the benefit associated with a tax position is measured as the largest amount that has a greater than 50% likelihood of being realized upon settlement. We classify interest and penalties related to uncertain tax positions, if any, in our financial statements as a component of general and administrative expense.
SEGMENT REPORTING	SEGMENT REPORTING. As of December 31, 2012, we have three operating segments. The first operating segment includes short term and long term residential care communities that offer dining for residents. Properties in this segment include leased and managed independent living communities, assisted living communities, skilled nursing facilities and rehabilitation hospitals. We earn rental income revenues from the tenants that lease and operate our leased communities and we earn fees and services revenues from the residents of our Managed Communities. Five Star began managing our Managed Communities for our account in June 2011. The second operating segment includes properties where medical related activities occur but where residential overnight stays and dining services are not provided. Properties in this segment include those leased to medical providers, medical related businesses, clinics and biotech laboratory tenants, or MOBs. The third operating segment includes amounts related to corporate business activities and the operating results of certain properties that offer fitness, wellness and spa services to members, which we do not consider to be sufficiently material as to constitute a separate reporting segment.
RECLASSIFICATIONS	RECLASSIFICATIONS. We have made reclassifications to the prior years' financial statements to conform to the current year's presentation. These reclassifications had no effect on net income or shareholders' equity.
NEW ACCOUNTING PRONOUNCEMENTS	NEW ACCOUNTING PRONOUNCEMENTS. In January 2012, we adopted the Financial Accounting Standards Board, or FASB, Accounting Standards Update No. 2011-04, Amendments to Achieve Common Fair Value Measurements and Disclosure Requirements in U.S. GAAP and IFRS. This update clarified the application of existing fair value measurement requirements. This update also required reporting entities to disclose additional information regarding fair value measurements categorized within Level 3 of the fair value hierarchy. This update was effective for interim and annual reporting periods beginning after December 15, 2011. The implementation of this update did not cause any material changes to the disclosures in, or presentation of, our consolidated financial statements. In January 2012, we adopted FASB Accounting Standards Update No. 2011-05, Presentation of Comprehensive Income. This update eliminated the option to report other comprehensive income and its components in the statement of shareholders' equity. This update was intended to enhance comparability between entities that report under generally accepted accounting principles, or GAAP, and to provide a more consistent method of presenting non-owner transactions that affect an entity's equity. This standard was effective for interim and annual reporting periods beginning after December 15, 2011. The implementation of this update did not cause any material changes to our consolidated financial statements.

Summary of Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2012

Summary of Significant Accounting Policies

BASIS OF PRESENTATION. Our consolidated financial statements include the accounts of Senior Housing Properties Trust, or we, us or our, and our subsidiaries, all of which are 100% owned directly or indirectly by us. All intercompany transactions and balances have been eliminated.

REAL ESTATE PROPERTIES

REAL ESTATE PROPERTIES. We depreciate real estate properties on a straight line basis over estimated useful lives of up to 40 years for buildings and improvements and up to 12 years for personal property. Our management regularly evaluates whether events or changes in circumstances have occurred that could indicate an impairment in the value of long lived assets. If there is an indication that the carrying value of an asset is not recoverable, we estimate the projected undiscounted cash flows to determine if an impairment loss should be recognized. We determine the amount of any impairment loss by comparing the historical carrying value to estimated fair value. We estimate fair value through an evaluation of recent financial performance and projected discounted cash flows using standard industry valuation techniques. In addition to consideration of impairment upon the events or changes in circumstances described above, we regularly evaluate the remaining lives of our long lived assets. If we change our estimate of the remaining lives, we allocate the carrying value of the affected assets over their revised remaining lives.

We allocate the consideration paid, generally cash plus the fair value of any assumed liabilities, for our properties among land, building and improvements and identified intangible assets and liabilities, consisting of the value of above market and below market leases, the value of in place leases and the value of tenant relationships. Purchase price allocations and the determination of useful lives are based on our estimates and, under some circumstances studies from independent real estate appraisal firms to provide market information and evaluations that are relevant to our purchase price allocations and determinations of useful lives; however, we are ultimately responsible for the purchase price allocations and determination of useful lives.

We allocate the consideration to land, building and improvements based on a determination of the fair values of these assets assuming the property is vacant. We determine the fair value of a property using methods that we believe are similar to those used by independent appraisers. Purchase price allocations to above market and below market leases are based on the estimated present value (using an interest rate which reflects our assessment of the risks associated with the leases acquired) of the difference between (i) the contractual amounts to be paid pursuant to the in place leases and (ii) our estimate of fair market lease rates for the corresponding leases, measured over a period equal to the remaining non-cancelable terms of the respective leases. Purchase price allocations to in place leases and tenant relationships are determined as the excess of (i) the purchase price paid for a property after adjusting existing in place leases to estimated market rental rates over (ii) the estimated fair value of the property as if vacant. We aggregate this value between in place lease values and tenant relationships based on our evaluation of the specific characteristics of each tenant's lease; however, the value of tenant relationships has not been separated from in place lease value for our properties because we believe such value and related amortization expense is immaterial for acquisitions reflected in our historical financial statements. We consider certain factors in performing these analyses including estimates of carrying costs during the expected lease up periods, including real estate taxes, insurance and other operating income and expenses and costs to execute similar leases in current market conditions, such as leasing commissions, legal and other related costs. If we believe the value of tenant relationships are material in the future, those amounts will be separately allocated and amortized over the estimated lives of the relationships. We recognize the excess, if any, of the consideration paid over amounts allocated to land, buildings and improvements and identified intangible assets and liabilities as goodwill.

We amortize capitalized above market lease values (included in acquired real estate leases in our consolidated balance sheets) as a reduction to rental income over the remaining non-cancelable terms of the respective leases. We amortize capitalized below market lease values (presented as acquired real estate lease obligations in our consolidated balance sheets) as an increase to rental income over the non-cancelable periods of the respective leases. We amortize the value of in place leases exclusive of the value of above market and below market in place leases to expense over the remaining non-cancelable periods of the respective leases. If a lease is terminated prior to its stated expiration, the unamortized amount relating to that lease is written off.

CASH AND CASH EQUIVALENTS

CASH AND CASH EQUIVALENTS. We carry cash and cash equivalents, consisting of overnight repurchase agreements and short term investments with original maturities of three months or less at the date of purchase, at cost plus accrued interest, which approximates fair value.

RESTRICTED CASH

RESTRICTED CASH. Restricted cash consists of amounts escrowed for real estate taxes, insurance and capital expenditures at certain of our mortgaged properties.

INVESTMENTS IN AVAILABLE FOR SALE SECURITIES

INVESTMENTS IN AVAILABLE FOR SALE SECURITIES. We own 250,000 common shares, or 0.3% at December 31, 2012, of CommonWealth REIT, or CWH. We also own 4,235,000 common shares, or 8.8% at December 31, 2012, of Five Star Quality Care, Inc., or Five Star. We classify these holdings as available for sale and carry them at fair value, with unrealized gains and losses reported as a separate component of shareholders' equity. Cumulative other comprehensive income shown in our consolidated balance sheets includes the net unrealized gain or loss on investments determined as the net difference between the market value of these shares of CWH and Five Star calculated by using weighted average quoted market prices on the dates we acquired these shares ($26.00 and $3.36 per share, respectively) and on December 31, 2012 ($15.84 and $5.01 per share, respectively). At December 31, 2012 and 2011, our investment in CWH had a fair value of $3,960 and $4,160, respectively, including an unrealized loss of $2,540 and $2,340, respectively. At December 31, 2012 and 2011, our investment in Five Star had a fair value of $21,217 and $12,705, respectively, including an unrealized gain (loss) of $7,003 and $(1,509), respectively.

EQUITY METHOD INVESTMENTS

EQUITY METHOD INVESTMENTS. We and the other seven current shareholders each currently own 12.5% of Affiliates Insurance Company, or AIC's, outstanding equity. Although we own less than 20% of AIC, we use the equity method to account for this investment because we believe that we have significant influence over AIC because all of our Trustees are also directors of AIC. Under the equity method, we record our percentage share of net earnings from AIC in our consolidated statements of income and comprehensive income. If we determine there is an "other than temporary impairment" in the fair value of this investment, we would record a charge to earnings. In evaluating the fair value of this investment, we have considered, among other things, the assets and liabilities held by AIC, AIC's overall financial condition and earning trends, and the financial condition and prospects for the insurance industry generally. See Note 5 for a further discussion of our investment in AIC.

DEFERRED FINANCING FEES

DEFERRED FINANCING FEES. We capitalize issuance costs related to borrowings and amortize them over the terms of the respective loans. During 2012, we capitalized $12,608 of issuance costs, including $11,439 related to our $350,000 senior notes issued in July 2012, $1,125 related to our assumption of mortgage loans during 2012 and $44 related to our $300,000 senior notes issued in December 2011. During 2011, we capitalized $13,760 of issuance costs, including $6,723 related to refinancing our revolving credit facility in June 2011, $2,540 related to our assumption of mortgage loans during 2011, $2,487 related to our $300,000 senior notes issued in December 2011, $1,973 related to our $250,000 senior notes issued in January 2011 and $37 related to our $512,934 Federal National Mortgage Association, or FNMA, mortgage financing we closed in August 2009. During 2010, we capitalized $4,661 of issuance costs, including $2,907 related to our $200,000 senior notes issued in April 2010, $903 related to our $512,934 FNMA mortgage financing we closed in August 2009, $826 related to our one year extension to December 31, 2011 on our $550,000 revolving credit facility and $25 related to our assumption of a mortgage loan in April 2010. During 2012, we wrote off $3,897 of unamortized deferred financing fees in connection with our prepayment of approximately $199,197 of the outstanding principal balance of our $512,934 FNMA mortgage financing we closed in August 2009. During 2011, we wrote off $427 of unamortized deferred financing fees in connection with the refinancing of our revolving credit facility. During 2010, we wrote off $1,153 of deferred financing fees and unamortized discounts in connection with the retirement of all of our 7.875% senior notes. The unamortized gross balance of deferred financing fees and related accumulated amortization was $39,471 and $10,061, and $36,144 and $10,710 at December 31, 2012 and 2011, respectively. The weighted average amortization period is approximately 14.7 years. We expect that the amortization expense for the five years subsequent to December 31, 2012 will be $4,748 in 2013, $4,695 in 2014, $3,621 in 2015, $2,170 in 2016, $1,861 in 2017 and $12,315, thereafter.

DEFERRED LEASING COSTS

DEFERRED LEASING COSTS. Deferred leasing costs include brokerage, legal and other fees associated with the successful negotiation of leases and are amortized on a straight line basis over the terms of the respective leases. Deferred leasing costs are included in other assets on our consolidated balance sheets. The unamortized gross balance of deferred leasing costs and related accumulated amortization was $6,917 and $1,793, and $4,663 and $902 at December 31, 2012 and 2011, respectively. The weighted average amortization period is approximately 6.4 years. We expect that the amortization expense for the five years subsequent to December 31, 2012 will be $1,017 in 2013, $946 in 2014, $843 in 2015, $674 in 2016, $530 in 2017 and $1,114, thereafter.

LOANS RECEIVABLE

LOANS RECEIVABLE. Loans receivable are stated at the unpaid principal balance. We recognized interest income based on the contractual terms in the loan agreement, which is included in interest and other income on our consolidated statements of income and comprehensive income.

ALLOWANCE FOR DOUBTFUL ACCOUNTS

ALLOWANCE FOR DOUBTFUL ACCOUNTS. We maintain an allowance for doubtful accounts for estimated losses resulting from the inability or unwillingness of certain tenants to make payments required under their leases. The computation of the allowance is based on the tenants' payment histories and current credit profiles, as well as other considerations. The net amount of our accounts receivables from third parties appear in other assets on our consolidated balance sheets.

REVENUE RECOGNITION

REVENUE RECOGNITION. We recognize rental income from operating leases on a straight line basis over the term of each lease agreement. We recognize percentage rents when realizable and earned, which is generally during the fourth quarter of the year. For the years ended December 31, 2012, 2011 and 2010, percentage rents earned aggregated $10,859, $11,313, and $10,315, respectively.

As of December 31, 2012, we own 39 senior living communities, including 29 communities that we acquired since June 2011 and the 10 senior living communities, or the 10 Communities, formerly leased to Sunrise Senior Living, Inc., or Sunrise, that are managed by Five Star. We refer to these 39 communities as the Managed Communities. We derive our revenues at these Managed Communities primarily from services to residents and we record revenues when services are provided. Our share of the net operating results of our Managed Communities in excess of the minimum returns due to us, or additional returns, are generally determined annually. We recognize additional returns due to us under our management agreements at year end when all contingencies are met and the income is earned. We had no additional returns in 2012 and 2011.

EARNINGS PER COMMON SHARE

EARNINGS PER COMMON SHARE. We compute earnings per common share using the weighted average number of shares outstanding during the period. We have no common share equivalents, instruments convertible into common shares or other dilutive instruments.

USE OF ESTIMATES

USE OF ESTIMATES. Accounting principles generally accepted in the United States requires us to make estimates and assumptions that may affect the amounts reported in these financial statements and related notes. The actual results could differ from these estimates.

INCOME TAXES

INCOME TAXES. We have elected to be taxed as a 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 our Managed Communities to our wholly owned taxable REIT subsidiaries, or TRSs, that, unlike most of our subsidiaries, files a separate tax return and are subject to federal and state income tax. Our consolidated income tax provision includes the income tax provision related to the operations of our TRSs and certain state income taxes incurred by us, despite our REIT status.

The Income Taxes Topic of the Codification prescribes how we should recognize, measure and present in our financial statements uncertain tax positions that have been taken or are expected to be taken in a tax return. Deferred tax benefits are recognized to the extent that it is "more likely than not" that a particular tax position will be sustained upon examination or audit. To the extent the "more likely than not" standard has been satisfied, the benefit associated with a tax position is measured as the largest amount that has a greater than 50% likelihood of being realized upon settlement. We classify interest and penalties related to uncertain tax positions, if any, in our financial statements as a component of general and administrative expense.

SEGMENT REPORTING

SEGMENT REPORTING. As of December 31, 2012, we have three operating segments. The first operating segment includes short term and long term residential care communities that offer dining for residents. Properties in this segment include leased and managed independent living communities, assisted living communities, skilled nursing facilities and rehabilitation hospitals. We earn rental income revenues from the tenants that lease and operate our leased communities and we earn fees and services revenues from the residents of our Managed Communities. Five Star began managing our Managed Communities for our account in June 2011. The second operating segment includes properties where medical related activities occur but where residential overnight stays and dining services are not provided. Properties in this segment include those leased to medical providers, medical related businesses, clinics and biotech laboratory tenants, or MOBs. The third operating segment includes amounts related to corporate business activities and the operating results of certain properties that offer fitness, wellness and spa services to members, which we do not consider to be sufficiently material as to constitute a separate reporting segment.

RECLASSIFICATIONS

RECLASSIFICATIONS. We have made reclassifications to the prior years' financial statements to conform to the current year's presentation. These reclassifications had no effect on net income or shareholders' equity.

NEW ACCOUNTING PRONOUNCEMENTS

NEW ACCOUNTING PRONOUNCEMENTS. In January 2012, we adopted the Financial Accounting Standards Board, or FASB, Accounting Standards Update No. 2011-04, Amendments to Achieve Common Fair Value Measurements and Disclosure Requirements in U.S. GAAP and IFRS. This update clarified the application of existing fair value measurement requirements. This update also required reporting entities to disclose additional information regarding fair value measurements categorized within Level 3 of the fair value hierarchy. This update was effective for interim and annual reporting periods beginning after December 15, 2011. The implementation of this update did not cause any material changes to the disclosures in, or presentation of, our consolidated financial statements.

In January 2012, we adopted FASB Accounting Standards Update No. 2011-05, Presentation of Comprehensive Income. This update eliminated the option to report other comprehensive income and its components in the statement of shareholders' equity. This update was intended to enhance comparability between entities that report under generally accepted accounting principles, or GAAP, and to provide a more consistent method of presenting non-owner transactions that affect an entity's equity. This standard was effective for interim and annual reporting periods beginning after December 15, 2011. The implementation of this update did not cause any material changes to our consolidated financial statements.