XML 27 R46.htm IDEA: XBRL DOCUMENT
v2.4.1.9

Indebtedness (Details 2) (USD $) In Thousands, unless otherwise specified | Dec. 31, 2014 | Oct. 31, 2014 | Dec. 31, 2013 | May 31, 2014 | Apr. 30, 2014 | Jul. 31, 2012 | Dec. 31, 2011
--- | --- | --- | --- | --- | --- | --- | ---
Indebtedness |  |  |  |  |  |  |
Face Amount | $ 1,750,000 us-gaap_DebtInstrumentFaceAmount |  | $ 1,100,000 us-gaap_DebtInstrumentFaceAmount |  |  |  |
Unamortized Discount | 6,373 us-gaap_DebtInstrumentUnamortizedDiscount |  | 6,663 us-gaap_DebtInstrumentUnamortizedDiscount |  |  |  |
Total secured | 627,076 snh_SecuredDebtAndCapitalLeaseObligations |  | 699,427 snh_SecuredDebtAndCapitalLeaseObligations |  |  |  |
Interest rate (as a percent) |  | 5.875%us-gaap_DebtInstrumentInterestRateStatedPercentage |  |  |  |  |
Initial Cost of Collateral | 6,238,611 us-gaap_RealEstateInvestmentPropertyAtCost |  | 5,263,625 us-gaap_RealEstateInvestmentPropertyAtCost |  |  |  |
Net Book Value of Collateral | 5,254,761 us-gaap_RealEstateInvestmentPropertyNet |  | 4,422,865 us-gaap_RealEstateInvestmentPropertyNet |  |  |  |
Unamortized net premiums | 2,937 us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet |  | 4,485 us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet |  |  |  |
Net book value of the assets encumbered by capital leases | 18,237 us-gaap_CapitalLeasesBalanceSheetAssetsByMajorClassNet |  | 18,627 us-gaap_CapitalLeasesBalanceSheetAssetsByMajorClassNet |  |  |  |
Required principal payments on outstanding debt |  |  |  |  |  |  |
2015 | 71,541 us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths |  |  |  |  |  |
2016 | 410,660 us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo |  |  |  |  |  |
2017 | 65,941 us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree |  |  |  |  |  |
2018 | 96,197 us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour |  |  |  |  |  |
2019 | 671,757 us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive |  |  |  |  |  |
Thereafter | 1,488,043 us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive |  |  |  |  |  |
Unsecured Debt |  |  |  |  |  |  |
Indebtedness |  |  |  |  |  |  |
Face Amount | 350,000 us-gaap_DebtInstrumentFaceAmount / us-gaap_DebtInstrumentAxis = us-gaap_UnsecuredDebtMember |  |  | 350,000 us-gaap_DebtInstrumentFaceAmount / us-gaap_DebtInstrumentAxis = us-gaap_UnsecuredDebtMember |  |  |
Interest rate (as a percent) | 1.60%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = us-gaap_UnsecuredDebtMember |  |  |  |  |  |
Senior unsecured notes 4.30% |  |  |  |  |  |  |
Indebtedness |  |  |  |  |  |  |
Face Amount | 250,000 us-gaap_DebtInstrumentFaceAmount / us-gaap_DebtInstrumentAxis = snh_SeniorUnsecuredNotes4.30PercentMember |  | 250,000 us-gaap_DebtInstrumentFaceAmount / us-gaap_DebtInstrumentAxis = snh_SeniorUnsecuredNotes4.30PercentMember |  |  |  |
Unamortized Discount | 551 us-gaap_DebtInstrumentUnamortizedDiscount / us-gaap_DebtInstrumentAxis = snh_SeniorUnsecuredNotes4.30PercentMember |  | 1,085 us-gaap_DebtInstrumentUnamortizedDiscount / us-gaap_DebtInstrumentAxis = snh_SeniorUnsecuredNotes4.30PercentMember |  |  |  |
Interest rate (as a percent) | 4.30%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = snh_SeniorUnsecuredNotes4.30PercentMember |  |  |  |  |  |
Senior unsecured notes 3.25% |  |  |  |  |  |  |
Indebtedness |  |  |  |  |  |  |
Face Amount | 400,000 us-gaap_DebtInstrumentFaceAmount / us-gaap_DebtInstrumentAxis = snh_SeniorUnsecuredNotes3.25PercentMember |  |  |  | 400,000 us-gaap_DebtInstrumentFaceAmount / us-gaap_DebtInstrumentAxis = snh_SeniorUnsecuredNotes3.25PercentMember |  |
Unamortized Discount | 256 us-gaap_DebtInstrumentUnamortizedDiscount / us-gaap_DebtInstrumentAxis = snh_SeniorUnsecuredNotes3.25PercentMember |  |  |  |  |  |
Interest rate (as a percent) | 3.25%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = snh_SeniorUnsecuredNotes3.25PercentMember |  |  |  | 3.25%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = snh_SeniorUnsecuredNotes3.25PercentMember |  |
Senior unsecured notes 6.75% |  |  |  |  |  |  |
Indebtedness |  |  |  |  |  |  |
Face Amount | 200,000 us-gaap_DebtInstrumentFaceAmount / us-gaap_DebtInstrumentAxis = snh_SeniorUnsecuredNotes6.75PercentMember |  | 200,000 us-gaap_DebtInstrumentFaceAmount / us-gaap_DebtInstrumentAxis = snh_SeniorUnsecuredNotes6.75PercentMember |  |  | 350,000 us-gaap_DebtInstrumentFaceAmount / us-gaap_DebtInstrumentAxis = snh_SeniorUnsecuredNotes6.75PercentMember | 300,000 us-gaap_DebtInstrumentFaceAmount / us-gaap_DebtInstrumentAxis = snh_SeniorUnsecuredNotes6.75PercentMember
Unamortized Discount | 1,133 us-gaap_DebtInstrumentUnamortizedDiscount / us-gaap_DebtInstrumentAxis = snh_SeniorUnsecuredNotes6.75PercentMember |  | 1,348 us-gaap_DebtInstrumentUnamortizedDiscount / us-gaap_DebtInstrumentAxis = snh_SeniorUnsecuredNotes6.75PercentMember |  |  |  |
Interest rate (as a percent) | 6.75%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = snh_SeniorUnsecuredNotes6.75PercentMember |  |  |  |  |  |
Unsecured senior notes due 2021 |  |  |  |  |  |  |
Indebtedness |  |  |  |  |  |  |
Face Amount | 300,000 us-gaap_DebtInstrumentFaceAmount / us-gaap_DebtInstrumentAxis = snh_SeniorUnsecuredNotes6.75PercentDue2021Member |  | 300,000 us-gaap_DebtInstrumentFaceAmount / us-gaap_DebtInstrumentAxis = snh_SeniorUnsecuredNotes6.75PercentDue2021Member |  |  |  |
Unamortized Discount | 3,696 us-gaap_DebtInstrumentUnamortizedDiscount / us-gaap_DebtInstrumentAxis = snh_SeniorUnsecuredNotes6.75PercentDue2021Member |  | 4,230 us-gaap_DebtInstrumentUnamortizedDiscount / us-gaap_DebtInstrumentAxis = snh_SeniorUnsecuredNotes6.75PercentDue2021Member |  |  |  |
Interest rate (as a percent) | 6.75%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = snh_SeniorUnsecuredNotes6.75PercentDue2021Member |  |  |  |  |  |
Senior unsecured notes 4.75% |  |  |  |  |  |  |
Indebtedness |  |  |  |  |  |  |
Face Amount | 250,000 us-gaap_DebtInstrumentFaceAmount / us-gaap_DebtInstrumentAxis = snh_SeniorUnsecuredNotes4.75PercentMember |  |  |  | 250,000 us-gaap_DebtInstrumentFaceAmount / us-gaap_DebtInstrumentAxis = snh_SeniorUnsecuredNotes4.75PercentMember |  |
Unamortized Discount | 737 us-gaap_DebtInstrumentUnamortizedDiscount / us-gaap_DebtInstrumentAxis = snh_SeniorUnsecuredNotes4.75PercentMember |  |  |  |  |  |
Interest rate (as a percent) | 4.75%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = snh_SeniorUnsecuredNotes4.75PercentMember |  |  |  | 4.75%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = snh_SeniorUnsecuredNotes4.75PercentMember |  |
Senior unsecured notes 5.625% due in 2042 |  |  |  |  |  |  |
Indebtedness |  |  |  |  |  |  |
Face Amount | 350,000 us-gaap_DebtInstrumentFaceAmount / us-gaap_DebtInstrumentAxis = snh_SeniorUnsecuredNotes5.625PercentDue2042Member |  | 350,000 us-gaap_DebtInstrumentFaceAmount / us-gaap_DebtInstrumentAxis = snh_SeniorUnsecuredNotes5.625PercentDue2042Member |  |  |  |
Interest rate (as a percent) | 5.625%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = snh_SeniorUnsecuredNotes5.625PercentDue2042Member |  |  |  |  |  |
Secured and Other Debt |  |  |  |  |  |  |
Indebtedness |  |  |  |  |  |  |
Total secured | 624,139 snh_SecuredDebtAndCapitalLeaseObligations / us-gaap_DebtInstrumentAxis = us-gaap_SecuredDebtMember |  | 694,942 snh_SecuredDebtAndCapitalLeaseObligations / us-gaap_DebtInstrumentAxis = us-gaap_SecuredDebtMember |  |  |  |
Number of properties as collateral | 47 snh_NumberOfRealEstatePropertiesCollateralized / us-gaap_DebtInstrumentAxis = us-gaap_SecuredDebtMember |  |  |  |  |  |
Initial Cost of Collateral | 1,419,482 us-gaap_RealEstateInvestmentPropertyAtCost / us-gaap_DebtInstrumentAxis = us-gaap_SecuredDebtMember |  |  |  |  |  |
Net Book Value of Collateral | 834,302 us-gaap_RealEstateInvestmentPropertyNet / us-gaap_DebtInstrumentAxis = us-gaap_SecuredDebtMember |  | 964,047 us-gaap_RealEstateInvestmentPropertyNet / us-gaap_DebtInstrumentAxis = us-gaap_SecuredDebtMember |  |  |  |
Mortgage 5.83% maturing in June 2014 |  |  |  |  |  |  |
Indebtedness |  |  |  |  |  |  |
Total secured |  |  | 36,145 snh_SecuredDebtAndCapitalLeaseObligations / us-gaap_DebtInstrumentAxis = snh_Mortgage5.83PercentDueJune2014Member |  |  |  |
Interest rate (as a percent) | 5.83%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = snh_Mortgage5.83PercentDueJune2014Member |  |  |  |  |  |
Initial Cost of Collateral | 79,000 us-gaap_RealEstateInvestmentPropertyAtCost / us-gaap_DebtInstrumentAxis = snh_Mortgage5.83PercentDueJune2014Member |  |  |  |  |  |
Net Book Value of Collateral |  |  | 77,799 us-gaap_RealEstateInvestmentPropertyNet / us-gaap_DebtInstrumentAxis = snh_Mortgage5.83PercentDueJune2014Member |  |  |  |
Mortgage 6.015% maturing in March 2015 |  |  |  |  |  |  |
Indebtedness |  |  |  |  |  |  |
Total secured | 29,362 snh_SecuredDebtAndCapitalLeaseObligations / us-gaap_DebtInstrumentAxis = snh_Mortgages6.015PercentDueMarch2015Member |  | 30,177 snh_SecuredDebtAndCapitalLeaseObligations / us-gaap_DebtInstrumentAxis = snh_Mortgages6.015PercentDueMarch2015Member |  |  |  |
Interest rate (as a percent) | 6.015%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = snh_Mortgages6.015PercentDueMarch2015Member |  |  |  |  |  |
Number of properties as collateral | 1 snh_NumberOfRealEstatePropertiesCollateralized / us-gaap_DebtInstrumentAxis = snh_Mortgages6.015PercentDueMarch2015Member |  |  |  |  |  |
Initial Cost of Collateral | 99,000 us-gaap_RealEstateInvestmentPropertyAtCost / us-gaap_DebtInstrumentAxis = snh_Mortgages6.015PercentDueMarch2015Member |  |  |  |  |  |
Net Book Value of Collateral | 94,245 us-gaap_RealEstateInvestmentPropertyNet / us-gaap_DebtInstrumentAxis = snh_Mortgages6.015PercentDueMarch2015Member |  | 96,354 us-gaap_RealEstateInvestmentPropertyNet / us-gaap_DebtInstrumentAxis = snh_Mortgages6.015PercentDueMarch2015Member |  |  |  |
Mortgage 6.25% maturing in May 2015 |  |  |  |  |  |  |
Indebtedness |  |  |  |  |  |  |
Total secured |  |  | 12,093 snh_SecuredDebtAndCapitalLeaseObligations / us-gaap_DebtInstrumentAxis = snh_Mortgage6.25PercentDueMay2015Member |  |  |  |
Interest rate (as a percent) | 6.25%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = snh_Mortgage6.25PercentDueMay2015Member |  |  |  |  |  |
Initial Cost of Collateral | 22,350 us-gaap_RealEstateInvestmentPropertyAtCost / us-gaap_DebtInstrumentAxis = snh_Mortgage6.25PercentDueMay2015Member |  |  |  |  |  |
Net Book Value of Collateral |  |  | 22,033 us-gaap_RealEstateInvestmentPropertyNet / us-gaap_DebtInstrumentAxis = snh_Mortgage6.25PercentDueMay2015Member |  |  |  |
Mortgage 5.65% maturing in June 2015 |  |  |  |  |  |  |
Indebtedness |  |  |  |  |  |  |
Total secured | 4,914 snh_SecuredDebtAndCapitalLeaseObligations / us-gaap_DebtInstrumentAxis = snh_Mortgage5.65PercentDueJune2015Member |  | 5,020 snh_SecuredDebtAndCapitalLeaseObligations / us-gaap_DebtInstrumentAxis = snh_Mortgage5.65PercentDueJune2015Member |  |  |  |
Interest rate (as a percent) | 5.65%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = snh_Mortgage5.65PercentDueJune2015Member |  |  |  |  |  |
Number of properties as collateral | 1 snh_NumberOfRealEstatePropertiesCollateralized / us-gaap_DebtInstrumentAxis = snh_Mortgage5.65PercentDueJune2015Member |  |  |  |  |  |
Initial Cost of Collateral | 22,143 us-gaap_RealEstateInvestmentPropertyAtCost / us-gaap_DebtInstrumentAxis = snh_Mortgage5.65PercentDueJune2015Member |  |  |  |  |  |
Net Book Value of Collateral | 20,511 us-gaap_RealEstateInvestmentPropertyNet / us-gaap_DebtInstrumentAxis = snh_Mortgage5.65PercentDueJune2015Member |  | 20,965 us-gaap_RealEstateInvestmentPropertyNet / us-gaap_DebtInstrumentAxis = snh_Mortgage5.65PercentDueJune2015Member |  |  |  |
Mortgage 6.37% maturing in July 2015 |  |  |  |  |  |  |
Indebtedness |  |  |  |  |  |  |
Total secured |  |  | 11,465 snh_SecuredDebtAndCapitalLeaseObligations / us-gaap_DebtInstrumentAxis = snh_Mortgage6.37PercentDueJuly2015Member |  |  |  |
Interest rate (as a percent) | 6.37%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = snh_Mortgage6.37PercentDueJuly2015Member |  |  |  |  |  |
Initial Cost of Collateral | 14,849 us-gaap_RealEstateInvestmentPropertyAtCost / us-gaap_DebtInstrumentAxis = snh_Mortgage6.37PercentDueJuly2015Member |  |  |  |  |  |
Net Book Value of Collateral |  |  | 14,197 us-gaap_RealEstateInvestmentPropertyNet / us-gaap_DebtInstrumentAxis = snh_Mortgage6.37PercentDueJuly2015Member |  |  |  |
Mortgage 5.66% maturing in July 2015 |  |  |  |  |  |  |
Indebtedness |  |  |  |  |  |  |
Total secured | 12,479 snh_SecuredDebtAndCapitalLeaseObligations / us-gaap_DebtInstrumentAxis = snh_Mortgage5.66PercentDueJuly2015Member |  | 12,773 snh_SecuredDebtAndCapitalLeaseObligations / us-gaap_DebtInstrumentAxis = snh_Mortgage5.66PercentDueJuly2015Member |  |  |  |
Interest rate (as a percent) | 5.66%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = snh_Mortgage5.66PercentDueJuly2015Member |  |  |  |  |  |
Number of properties as collateral | 3 snh_NumberOfRealEstatePropertiesCollateralized / us-gaap_DebtInstrumentAxis = snh_Mortgage5.66PercentDueJuly2015Member |  |  |  |  |  |
Initial Cost of Collateral | 26,606 us-gaap_RealEstateInvestmentPropertyAtCost / us-gaap_DebtInstrumentAxis = snh_Mortgage5.66PercentDueJuly2015Member |  |  |  |  |  |
Net Book Value of Collateral | 24,948 us-gaap_RealEstateInvestmentPropertyNet / us-gaap_DebtInstrumentAxis = snh_Mortgage5.66PercentDueJuly2015Member |  | 25,457 us-gaap_RealEstateInvestmentPropertyNet / us-gaap_DebtInstrumentAxis = snh_Mortgage5.66PercentDueJuly2015Member |  |  |  |
Mortgage 5.880% maturing in July 2015 |  |  |  |  |  |  |
Indebtedness |  |  |  |  |  |  |
Total secured | 2,728 snh_SecuredDebtAndCapitalLeaseObligations / us-gaap_DebtInstrumentAxis = snh_Mortgage5.88PercentDueJuly2015Member |  | 2,805 snh_SecuredDebtAndCapitalLeaseObligations / us-gaap_DebtInstrumentAxis = snh_Mortgage5.88PercentDueJuly2015Member |  |  |  |
Interest rate (as a percent) | 5.88%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = snh_Mortgage5.88PercentDueJuly2015Member |  |  |  |  |  |
Number of properties as collateral | 1 snh_NumberOfRealEstatePropertiesCollateralized / us-gaap_DebtInstrumentAxis = snh_Mortgage5.88PercentDueJuly2015Member |  |  |  |  |  |
Initial Cost of Collateral | 15,397 us-gaap_RealEstateInvestmentPropertyAtCost / us-gaap_DebtInstrumentAxis = snh_Mortgage5.88PercentDueJuly2015Member |  |  |  |  |  |
Net Book Value of Collateral | 13,991 us-gaap_RealEstateInvestmentPropertyNet / us-gaap_DebtInstrumentAxis = snh_Mortgage5.88PercentDueJuly2015Member |  | 14,384 us-gaap_RealEstateInvestmentPropertyNet / us-gaap_DebtInstrumentAxis = snh_Mortgage5.88PercentDueJuly2015Member |  |  |  |
Mortgage 5.81% maturing in October 2015 |  |  |  |  |  |  |
Indebtedness |  |  |  |  |  |  |
Total secured | 6,353 snh_SecuredDebtAndCapitalLeaseObligations / us-gaap_DebtInstrumentAxis = snh_Mortgage5.81PercentDueOctober2015Member |  | 6,579 snh_SecuredDebtAndCapitalLeaseObligations / us-gaap_DebtInstrumentAxis = snh_Mortgage5.81PercentDueOctober2015Member |  |  |  |
Interest rate (as a percent) | 5.81%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = snh_Mortgage5.81PercentDueOctober2015Member |  |  |  |  |  |
Number of properties as collateral | 1 snh_NumberOfRealEstatePropertiesCollateralized / us-gaap_DebtInstrumentAxis = snh_Mortgage5.81PercentDueOctober2015Member |  |  |  |  |  |
Initial Cost of Collateral | 9,650 us-gaap_RealEstateInvestmentPropertyAtCost / us-gaap_DebtInstrumentAxis = snh_Mortgage5.81PercentDueOctober2015Member |  |  |  |  |  |
Net Book Value of Collateral | 9,927 us-gaap_RealEstateInvestmentPropertyNet / us-gaap_DebtInstrumentAxis = snh_Mortgage5.81PercentDueOctober2015Member |  | 9,474 us-gaap_RealEstateInvestmentPropertyNet / us-gaap_DebtInstrumentAxis = snh_Mortgage5.81PercentDueOctober2015Member |  |  |  |
Mortgage 5.810% maturing in October 2015, Two |  |  |  |  |  |  |
Indebtedness |  |  |  |  |  |  |
Total secured | 4,403 snh_SecuredDebtAndCapitalLeaseObligations / us-gaap_DebtInstrumentAxis = snh_Mortgage5.81PercentDueOctober2015TwoMember |  | 4,502 snh_SecuredDebtAndCapitalLeaseObligations / us-gaap_DebtInstrumentAxis = snh_Mortgage5.81PercentDueOctober2015TwoMember |  |  |  |
Interest rate (as a percent) | 5.81%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = snh_Mortgage5.81PercentDueOctober2015TwoMember |  |  |  |  |  |
Number of properties as collateral | 1 snh_NumberOfRealEstatePropertiesCollateralized / us-gaap_DebtInstrumentAxis = snh_Mortgage5.81PercentDueOctober2015TwoMember |  |  |  |  |  |
Initial Cost of Collateral | 8,600 us-gaap_RealEstateInvestmentPropertyAtCost / us-gaap_DebtInstrumentAxis = snh_Mortgage5.81PercentDueOctober2015TwoMember |  |  |  |  |  |
Net Book Value of Collateral | 8,211 us-gaap_RealEstateInvestmentPropertyNet / us-gaap_DebtInstrumentAxis = snh_Mortgage5.81PercentDueOctober2015TwoMember |  | 8,168 us-gaap_RealEstateInvestmentPropertyNet / us-gaap_DebtInstrumentAxis = snh_Mortgage5.81PercentDueOctober2015TwoMember |  |  |  |
Mortgage 5.64% maturing in January 2016 |  |  |  |  |  |  |
Indebtedness |  |  |  |  |  |  |
Total secured | 52,000 snh_SecuredDebtAndCapitalLeaseObligations / us-gaap_DebtInstrumentAxis = snh_Mortgage5.64PercentDueJanuary2016Member |  | 52,000 snh_SecuredDebtAndCapitalLeaseObligations / us-gaap_DebtInstrumentAxis = snh_Mortgage5.64PercentDueJanuary2016Member |  |  |  |
Interest rate (as a percent) | 5.64%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = snh_Mortgage5.64PercentDueJanuary2016Member |  |  |  |  |  |
Number of properties as collateral | 1 snh_NumberOfRealEstatePropertiesCollateralized / us-gaap_DebtInstrumentAxis = snh_Mortgage5.64PercentDueJanuary2016Member |  |  |  |  |  |
Initial Cost of Collateral | 70,495 us-gaap_RealEstateInvestmentPropertyAtCost / us-gaap_DebtInstrumentAxis = snh_Mortgage5.64PercentDueJanuary2016Member |  |  |  |  |  |
Net Book Value of Collateral | 64,175 us-gaap_RealEstateInvestmentPropertyNet / us-gaap_DebtInstrumentAxis = snh_Mortgage5.64PercentDueJanuary2016Member |  | 64,904 us-gaap_RealEstateInvestmentPropertyNet / us-gaap_DebtInstrumentAxis = snh_Mortgage5.64PercentDueJanuary2016Member |  |  |  |
Mortgage 5.97% maturing in April 2016 |  |  |  |  |  |  |
Indebtedness |  |  |  |  |  |  |
Total secured | 6,243 snh_SecuredDebtAndCapitalLeaseObligations / us-gaap_DebtInstrumentAxis = snh_Mortgage5.97PercentDueApril2016Member |  | 6,363 snh_SecuredDebtAndCapitalLeaseObligations / us-gaap_DebtInstrumentAxis = snh_Mortgage5.97PercentDueApril2016Member |  |  |  |
Interest rate (as a percent) | 5.97%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = snh_Mortgage5.97PercentDueApril2016Member |  |  |  |  |  |
Number of properties as collateral | 1 snh_NumberOfRealEstatePropertiesCollateralized / us-gaap_DebtInstrumentAxis = snh_Mortgage5.97PercentDueApril2016Member |  |  |  |  |  |
Initial Cost of Collateral | 10,272 us-gaap_RealEstateInvestmentPropertyAtCost / us-gaap_DebtInstrumentAxis = snh_Mortgage5.97PercentDueApril2016Member |  |  |  |  |  |
Net Book Value of Collateral | 9,552 us-gaap_RealEstateInvestmentPropertyNet / us-gaap_DebtInstrumentAxis = snh_Mortgage5.97PercentDueApril2016Member |  | 9,811 us-gaap_RealEstateInvestmentPropertyNet / us-gaap_DebtInstrumentAxis = snh_Mortgage5.97PercentDueApril2016Member |  |  |  |
Mortgage 5.92% maturing in November 2016 |  |  |  |  |  |  |
Indebtedness |  |  |  |  |  |  |
Total secured | 85,085 snh_SecuredDebtAndCapitalLeaseObligations / us-gaap_DebtInstrumentAxis = snh_Mortgage5.92PercentDueNovember2016Member |  | 87,928 snh_SecuredDebtAndCapitalLeaseObligations / us-gaap_DebtInstrumentAxis = snh_Mortgage5.92PercentDueNovember2016Member |  |  |  |
Interest rate (as a percent) | 5.92%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = snh_Mortgage5.92PercentDueNovember2016Member |  |  |  |  |  |
Number of properties as collateral | 2 snh_NumberOfRealEstatePropertiesCollateralized / us-gaap_DebtInstrumentAxis = snh_Mortgage5.92PercentDueNovember2016Member |  |  |  |  |  |
Initial Cost of Collateral | 157,500 us-gaap_RealEstateInvestmentPropertyAtCost / us-gaap_DebtInstrumentAxis = snh_Mortgage5.92PercentDueNovember2016Member |  |  |  |  |  |
Net Book Value of Collateral | 150,036 us-gaap_RealEstateInvestmentPropertyNet / us-gaap_DebtInstrumentAxis = snh_Mortgage5.92PercentDueNovember2016Member |  | 151,928 us-gaap_RealEstateInvestmentPropertyNet / us-gaap_DebtInstrumentAxis = snh_Mortgage5.92PercentDueNovember2016Member |  |  |  |
Mortgage 6.25% maturing in November 2016 |  |  |  |  |  |  |
Indebtedness |  |  |  |  |  |  |
Total secured | 12,184 snh_SecuredDebtAndCapitalLeaseObligations / us-gaap_DebtInstrumentAxis = snh_Mortgage6.25PercentDueNovember2016Member |  | 12,366 snh_SecuredDebtAndCapitalLeaseObligations / us-gaap_DebtInstrumentAxis = snh_Mortgage6.25PercentDueNovember2016Member |  |  |  |
Interest rate (as a percent) | 6.25%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = snh_Mortgage6.25PercentDueNovember2016Member |  |  |  |  |  |
Number of properties as collateral | 1 snh_NumberOfRealEstatePropertiesCollateralized / us-gaap_DebtInstrumentAxis = snh_Mortgage6.25PercentDueNovember2016Member |  |  |  |  |  |
Initial Cost of Collateral | 22,102 us-gaap_RealEstateInvestmentPropertyAtCost / us-gaap_DebtInstrumentAxis = snh_Mortgage6.25PercentDueNovember2016Member |  |  |  |  |  |
Net Book Value of Collateral | 21,255 us-gaap_RealEstateInvestmentPropertyNet / us-gaap_DebtInstrumentAxis = snh_Mortgage6.25PercentDueNovember2016Member |  | 21,672 us-gaap_RealEstateInvestmentPropertyNet / us-gaap_DebtInstrumentAxis = snh_Mortgage6.25PercentDueNovember2016Member |  |  |  |
Mortgage 5.86% maturing in March 2017 |  |  |  |  |  |  |
Indebtedness |  |  |  |  |  |  |
Total secured | 5,625 snh_SecuredDebtAndCapitalLeaseObligations / us-gaap_DebtInstrumentAxis = snh_Mortgage5.86PercentDueMarch2017Member |  | 5,720 snh_SecuredDebtAndCapitalLeaseObligations / us-gaap_DebtInstrumentAxis = snh_Mortgage5.86PercentDueMarch2017Member |  |  |  |
Interest rate (as a percent) | 5.86%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = snh_Mortgage5.86PercentDueMarch2017Member |  |  |  |  |  |
Number of properties as collateral | 1 snh_NumberOfRealEstatePropertiesCollateralized / us-gaap_DebtInstrumentAxis = snh_Mortgage5.86PercentDueMarch2017Member |  |  |  |  |  |
Initial Cost of Collateral | 11,280 us-gaap_RealEstateInvestmentPropertyAtCost / us-gaap_DebtInstrumentAxis = snh_Mortgage5.86PercentDueMarch2017Member |  |  |  |  |  |
Net Book Value of Collateral | 11,004 us-gaap_RealEstateInvestmentPropertyNet / us-gaap_DebtInstrumentAxis = snh_Mortgage5.86PercentDueMarch2017Member |  | 11,292 us-gaap_RealEstateInvestmentPropertyNet / us-gaap_DebtInstrumentAxis = snh_Mortgage5.86PercentDueMarch2017Member |  |  |  |
Mortgages 6.54% maturing in May 2017 |  |  |  |  |  |  |
Indebtedness |  |  |  |  |  |  |
Total secured | 44,687 snh_SecuredDebtAndCapitalLeaseObligations / us-gaap_DebtInstrumentAxis = snh_Mortgages6.54PercentDueMay2017Member |  | 45,753 snh_SecuredDebtAndCapitalLeaseObligations / us-gaap_DebtInstrumentAxis = snh_Mortgages6.54PercentDueMay2017Member |  |  |  |
Interest rate (as a percent) | 6.54%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = snh_Mortgages6.54PercentDueMay2017Member |  |  |  |  |  |
Number of properties as collateral | 8 snh_NumberOfRealEstatePropertiesCollateralized / us-gaap_DebtInstrumentAxis = snh_Mortgages6.54PercentDueMay2017Member |  |  |  |  |  |
Initial Cost of Collateral | 62,500 us-gaap_RealEstateInvestmentPropertyAtCost / us-gaap_DebtInstrumentAxis = snh_Mortgages6.54PercentDueMay2017Member |  |  |  |  |  |
Net Book Value of Collateral | 53,878 us-gaap_RealEstateInvestmentPropertyNet / us-gaap_DebtInstrumentAxis = snh_Mortgages6.54PercentDueMay2017Member |  | 54,702 us-gaap_RealEstateInvestmentPropertyNet / us-gaap_DebtInstrumentAxis = snh_Mortgages6.54PercentDueMay2017Member |  |  |  |
Mortgages 6.150% maturing in August 2017 |  |  |  |  |  |  |
Indebtedness |  |  |  |  |  |  |
Total secured | 11,059 snh_SecuredDebtAndCapitalLeaseObligations / us-gaap_DebtInstrumentAxis = snh_Mortgage6.15PercentDueAugust2017Member |  | 11,245 snh_SecuredDebtAndCapitalLeaseObligations / us-gaap_DebtInstrumentAxis = snh_Mortgage6.15PercentDueAugust2017Member |  |  |  |
Interest rate (as a percent) | 6.15%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = snh_Mortgage6.15PercentDueAugust2017Member |  |  |  |  |  |
Number of properties as collateral | 1 snh_NumberOfRealEstatePropertiesCollateralized / us-gaap_DebtInstrumentAxis = snh_Mortgage6.15PercentDueAugust2017Member |  |  |  |  |  |
Initial Cost of Collateral | 16,400 us-gaap_RealEstateInvestmentPropertyAtCost / us-gaap_DebtInstrumentAxis = snh_Mortgage6.15PercentDueAugust2017Member |  |  |  |  |  |
Net Book Value of Collateral | 14,846 us-gaap_RealEstateInvestmentPropertyNet / us-gaap_DebtInstrumentAxis = snh_Mortgage6.15PercentDueAugust2017Member |  | 15,180 us-gaap_RealEstateInvestmentPropertyNet / us-gaap_DebtInstrumentAxis = snh_Mortgage6.15PercentDueAugust2017Member |  |  |  |
Mortgages 6.73% maturing in April 2018 |  |  |  |  |  |  |
Indebtedness |  |  |  |  |  |  |
Total secured | 9,195 snh_SecuredDebtAndCapitalLeaseObligations / us-gaap_DebtInstrumentAxis = snh_Mortgage6.73PercentDueApril2018Member |  | 9,425 snh_SecuredDebtAndCapitalLeaseObligations / us-gaap_DebtInstrumentAxis = snh_Mortgage6.73PercentDueApril2018Member |  |  |  |
Interest rate (as a percent) | 6.73%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = snh_Mortgage6.73PercentDueApril2018Member |  |  |  |  |  |
Number of properties as collateral | 1 snh_NumberOfRealEstatePropertiesCollateralized / us-gaap_DebtInstrumentAxis = snh_Mortgage6.73PercentDueApril2018Member |  |  |  |  |  |
Initial Cost of Collateral | 15,100 us-gaap_RealEstateInvestmentPropertyAtCost / us-gaap_DebtInstrumentAxis = snh_Mortgage6.73PercentDueApril2018Member |  |  |  |  |  |
Net Book Value of Collateral | 11,103 us-gaap_RealEstateInvestmentPropertyNet / us-gaap_DebtInstrumentAxis = snh_Mortgage6.73PercentDueApril2018Member |  | 11,299 us-gaap_RealEstateInvestmentPropertyNet / us-gaap_DebtInstrumentAxis = snh_Mortgage6.73PercentDueApril2018Member |  |  |  |
Mortgage 6.71% maturing in Sept 2019 |  |  |  |  |  |  |
Indebtedness |  |  |  |  |  |  |
Total secured | 288,519 snh_SecuredDebtAndCapitalLeaseObligations / us-gaap_DebtInstrumentAxis = snh_Mortgage6.71PercentDueSept2019Member |  | 292,611 snh_SecuredDebtAndCapitalLeaseObligations / us-gaap_DebtInstrumentAxis = snh_Mortgage6.71PercentDueSept2019Member |  |  |  |
Interest rate (as a percent) | 6.71%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = snh_Mortgage6.71PercentDueSept2019Member |  |  |  |  |  |
Number of properties as collateral | 17 snh_NumberOfRealEstatePropertiesCollateralized / us-gaap_DebtInstrumentAxis = snh_Mortgage6.71PercentDueSept2019Member |  |  |  |  |  |
Initial Cost of Collateral | 617,161 us-gaap_RealEstateInvestmentPropertyAtCost / us-gaap_DebtInstrumentAxis = snh_Mortgage6.71PercentDueSept2019Member |  |  |  |  |  |
Net Book Value of Collateral | 245,593 us-gaap_RealEstateInvestmentPropertyNet / us-gaap_DebtInstrumentAxis = snh_Mortgage6.71PercentDueSept2019Member |  | 252,404 us-gaap_RealEstateInvestmentPropertyNet / us-gaap_DebtInstrumentAxis = snh_Mortgage6.71PercentDueSept2019Member |  |  |  |
Mortgage 7.31% and 7.85% maturing in Jan 2022 |  |  |  |  |  |  |
Indebtedness |  |  |  |  |  |  |
Number of mortgages | 2 snh_DebtInstrumentNumberOfMortgages / us-gaap_DebtInstrumentAxis = snh_Mortgage7.31PercentAnd7.85PercentDueJan2022Member |  |  |  |  |  |
Mortgage 7.31% maturing in Jan 2022 |  |  |  |  |  |  |
Indebtedness |  |  |  |  |  |  |
Total secured | 2,723 snh_SecuredDebtAndCapitalLeaseObligations / us-gaap_DebtInstrumentAxis = snh_Mortgage7.31PercentDueJan2022Member |  | 3,007 snh_SecuredDebtAndCapitalLeaseObligations / us-gaap_DebtInstrumentAxis = snh_Mortgage7.31PercentDueJan2022Member |  |  |  |
Interest rate (as a percent) | 7.31%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = snh_Mortgage7.31PercentDueJan2022Member |  |  |  |  |  |
Number of properties as collateral | 1 snh_NumberOfRealEstatePropertiesCollateralized / us-gaap_DebtInstrumentAxis = snh_Mortgage7.31PercentDueJan2022Member |  |  |  |  |  |
Initial Cost of Collateral | 18,827 us-gaap_RealEstateInvestmentPropertyAtCost / us-gaap_DebtInstrumentAxis = snh_Mortgage7.31PercentDueJan2022Member |  |  |  |  |  |
Net Book Value of Collateral | 16,136 us-gaap_RealEstateInvestmentPropertyNet / us-gaap_DebtInstrumentAxis = snh_Mortgage7.31PercentDueJan2022Member |  | 16,478 us-gaap_RealEstateInvestmentPropertyNet / us-gaap_DebtInstrumentAxis = snh_Mortgage7.31PercentDueJan2022Member |  |  |  |
Mortgage 7.85% maturing in Jan 2022 |  |  |  |  |  |  |
Indebtedness |  |  |  |  |  |  |
Total secured | 1,345 snh_SecuredDebtAndCapitalLeaseObligations / us-gaap_DebtInstrumentAxis = snh_Mortgage7.85PercentDueJan2022Member |  | 1,482 snh_SecuredDebtAndCapitalLeaseObligations / us-gaap_DebtInstrumentAxis = snh_Mortgage7.85PercentDueJan2022Member |  |  |  |
Interest rate (as a percent) | 7.85%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = snh_Mortgage7.85PercentDueJan2022Member |  |  |  |  |  |
Mortgage 6.28% maturing in July 2022 |  |  |  |  |  |  |
Indebtedness |  |  |  |  |  |  |
Total secured | 15,318 snh_SecuredDebtAndCapitalLeaseObligations / us-gaap_DebtInstrumentAxis = snh_Mortgages6.28PercentDueJuly2022Member |  |  |  |  |  |
Interest rate (as a percent) | 6.28%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = snh_Mortgages6.28PercentDueJuly2022Member |  |  |  |  |  |
Number of properties as collateral | 1 snh_NumberOfRealEstatePropertiesCollateralized / us-gaap_DebtInstrumentAxis = snh_Mortgages6.28PercentDueJuly2022Member |  |  |  |  |  |
Initial Cost of Collateral | 32,658 us-gaap_RealEstateInvestmentPropertyAtCost / us-gaap_DebtInstrumentAxis = snh_Mortgages6.28PercentDueJuly2022Member |  |  |  |  |  |
Net Book Value of Collateral | 25,848 us-gaap_RealEstateInvestmentPropertyNet / us-gaap_DebtInstrumentAxis = snh_Mortgages6.28PercentDueJuly2022Member |  |  |  |  |  |
Mortgage 6.25% maturing in February 2033 |  |  |  |  |  |  |
Indebtedness |  |  |  |  |  |  |
Total secured | 3,348 snh_SecuredDebtAndCapitalLeaseObligations / us-gaap_DebtInstrumentAxis = snh_Mortgage6.25PercentDueFebruary2033Member |  | 3,444 snh_SecuredDebtAndCapitalLeaseObligations / us-gaap_DebtInstrumentAxis = snh_Mortgage6.25PercentDueFebruary2033Member |  |  |  |
Interest rate (as a percent) | 6.25%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = snh_Mortgage6.25PercentDueFebruary2033Member |  |  |  |  |  |
Initial Cost of Collateral | 5,200 us-gaap_RealEstateInvestmentPropertyAtCost / us-gaap_DebtInstrumentAxis = snh_Mortgage6.25PercentDueFebruary2033Member |  |  |  |  |  |
Net Book Value of Collateral | 4,483 us-gaap_RealEstateInvestmentPropertyNet / us-gaap_DebtInstrumentAxis = snh_Mortgage6.25PercentDueFebruary2033Member |  | 4,588 us-gaap_RealEstateInvestmentPropertyNet / us-gaap_DebtInstrumentAxis = snh_Mortgage6.25PercentDueFebruary2033Member |  |  |  |
Mortgage 5.95% maturing in August 2037 |  |  |  |  |  |  |
Indebtedness |  |  |  |  |  |  |
Total secured | 9,205 snh_SecuredDebtAndCapitalLeaseObligations / us-gaap_DebtInstrumentAxis = snh_Mortgages5.95PercentDueAugust2037Member |  | 9,353 snh_SecuredDebtAndCapitalLeaseObligations / us-gaap_DebtInstrumentAxis = snh_Mortgages5.95PercentDueAugust2037Member |  |  |  |
Interest rate (as a percent) | 5.95%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = snh_Mortgages5.95PercentDueAugust2037Member |  |  |  |  |  |
Number of properties as collateral | 1 snh_NumberOfRealEstatePropertiesCollateralized / us-gaap_DebtInstrumentAxis = snh_Mortgages5.95PercentDueAugust2037Member |  |  |  |  |  |
Initial Cost of Collateral | 11,425 us-gaap_RealEstateInvestmentPropertyAtCost / us-gaap_DebtInstrumentAxis = snh_Mortgages5.95PercentDueAugust2037Member |  |  |  |  |  |
Net Book Value of Collateral | 8,865 us-gaap_RealEstateInvestmentPropertyNet / us-gaap_DebtInstrumentAxis = snh_Mortgages5.95PercentDueAugust2037Member |  | 9,080 us-gaap_RealEstateInvestmentPropertyNet / us-gaap_DebtInstrumentAxis = snh_Mortgages5.95PercentDueAugust2037Member |  |  |  |
Mortgage 4.38% maturing in September 2043 |  |  |  |  |  |  |
Indebtedness |  |  |  |  |  |  |
Total secured | 4,594 snh_SecuredDebtAndCapitalLeaseObligations / us-gaap_DebtInstrumentAxis = snh_Mortgage4.38PercentDueSeptember2043Member |  | 4,672 snh_SecuredDebtAndCapitalLeaseObligations / us-gaap_DebtInstrumentAxis = snh_Mortgage4.38PercentDueSeptember2043Member |  |  |  |
Interest rate (as a percent) | 4.375%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = snh_Mortgage4.38PercentDueSeptember2043Member |  |  |  |  |  |
Number of properties as collateral | 1 snh_NumberOfRealEstatePropertiesCollateralized / us-gaap_DebtInstrumentAxis = snh_Mortgage4.38PercentDueSeptember2043Member |  |  |  |  |  |
Initial Cost of Collateral | 8,059 us-gaap_RealEstateInvestmentPropertyAtCost / us-gaap_DebtInstrumentAxis = snh_Mortgage4.38PercentDueSeptember2043Member |  |  |  |  |  |
Net Book Value of Collateral | 7,459 us-gaap_RealEstateInvestmentPropertyNet / us-gaap_DebtInstrumentAxis = snh_Mortgage4.38PercentDueSeptember2043Member |  | 7,632 us-gaap_RealEstateInvestmentPropertyNet / us-gaap_DebtInstrumentAxis = snh_Mortgage4.38PercentDueSeptember2043Member |  |  |  |
Mortgage bonds |  |  |  |  |  |  |
Indebtedness |  |  |  |  |  |  |
Total secured |  |  | 14,700 snh_SecuredDebtAndCapitalLeaseObligations / us-gaap_DebtInstrumentAxis = snh_BondsPayableMember |  |  |  |
Interest rate (as a percent) | 5.875%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = snh_BondsPayableMember |  |  |  |  |  |
Initial Cost of Collateral | 34,307 us-gaap_RealEstateInvestmentPropertyAtCost / us-gaap_DebtInstrumentAxis = snh_BondsPayableMember |  |  |  |  |  |
Net Book Value of Collateral |  |  | 25,619 us-gaap_RealEstateInvestmentPropertyNet / us-gaap_DebtInstrumentAxis = snh_BondsPayableMember |  |  |  |
Capital leases |  |  |  |  |  |  |
Indebtedness |  |  |  |  |  |  |
Total secured | 12,770 snh_SecuredDebtAndCapitalLeaseObligations / us-gaap_DebtInstrumentAxis = us-gaap_CapitalLeaseObligationsMember |  | 13,314 snh_SecuredDebtAndCapitalLeaseObligations / us-gaap_DebtInstrumentAxis = us-gaap_CapitalLeaseObligationsMember |  |  |  |
Interest rate (as a percent) | 7.70%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = us-gaap_CapitalLeaseObligationsMember |  |  |  |  |  |
Number of properties as collateral | 2 snh_NumberOfRealEstatePropertiesCollateralized / us-gaap_DebtInstrumentAxis = us-gaap_CapitalLeaseObligationsMember |  |  |  |  |  |
Initial Cost of Collateral | 28,601 us-gaap_RealEstateInvestmentPropertyAtCost / us-gaap_DebtInstrumentAxis = us-gaap_CapitalLeaseObligationsMember |  |  |  |  |  |
Net Book Value of Collateral | $ 18,237 us-gaap_RealEstateInvestmentPropertyNet / us-gaap_DebtInstrumentAxis = us-gaap_CapitalLeaseObligationsMember |  | $ 18,627 us-gaap_RealEstateInvestmentPropertyNet / us-gaap_DebtInstrumentAxis = us-gaap_CapitalLeaseObligationsMember |  |  |  |

X
- Definition Represents the number of mortgage loans collateralized by a MOB property. + References No definition available. + Details
Name: | snh_DebtInstrumentNumberOfMortgages
Namespace Prefix: | snh_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition The number of real estate properties serving as collateral for debt as of the balance sheet date. + References No definition available. + Details
Name: | snh_NumberOfRealEstatePropertiesCollateralized
Namespace Prefix: | snh_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Carrying value as of the balance sheet date, including the current and noncurrent portions, of collateralized debt obligations (with maturities initially due after one year or beyond the operating cycle, if longer). Such obligations include mortgage loans, chattel loans, and any other borrowings secured by assets of the borrower and amount equal to the present value (the principal) at the beginning of the lease term of minimum lease payments during the lease term (excluding that portion of the payments representing executory costs such as insurance, maintenance, and taxes to be paid by the lessor, together with any profit thereon) net of payments or other amounts applied to the principal through the balance sheet date. + References No definition available. + Details
Name: | snh_SecuredDebtAndCapitalLeaseObligations
Namespace Prefix: | snh_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The total gross amount less the charge for the use of the long-lived depreciable assets subject to a lease meeting the criteria for capitalization. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 840 -SubTopic 30 -Section 50 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=6455398&loc=d3e45280-112737 + Details
Name: | us-gaap_CapitalLeasesBalanceSheetAssetsByMajorClassNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Face (par) amount of debt instrument at time of issuance. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 55 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=34725769&loc=d3e28878-108400 + Details
Name: | us-gaap_DebtInstrumentFaceAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Contractual interest rate for funds borrowed, under the debt agreement. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | us-gaap_DebtInstrumentLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The amount of debt discount that was originally recognized at the issuance of the instrument that has yet to be amortized. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 1A -URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28541-108399 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 55 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=34725769&loc=d3e28878-108400 + Details
Name: | us-gaap_DebtInstrumentUnamortizedDiscount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The amount of debt discount (net of debt premium) that was originally recognized at the issuance of the instrument that has yet to be amortized. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28555-108399 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28567-108399 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 1A -URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28541-108399 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 55 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=34725769&loc=d3e28878-108400 + Details
Name: | us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_LongTermDebtByMaturityAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing after the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6802200&loc=d3e1835-112601 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-04.(a)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24072-122690 + Details
Name: | us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing in the next fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6802200&loc=d3e1835-112601 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-04.(a)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24072-122690 + Details
Name: | us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing in the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6802200&loc=d3e1835-112601 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-04.(a)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24072-122690 + Details
Name: | us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing in the fourth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6802200&loc=d3e1835-112601 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-04.(a)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24072-122690 + Details
Name: | us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing in the third fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6802200&loc=d3e1835-112601 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-04.(a)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24072-122690 + Details
Name: | us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing in the second fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6802200&loc=d3e1835-112601 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-04.(a)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24072-122690 + Details
Name: | us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of real estate investment property which may include the following: (1) land available-for-sale; (2) land available-for-development; (3) investments in building and building improvements; (4) tenant allowances; (5) developments in-process; (6) rental properties; and (7) other real estate investments. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03.1(d)) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 + Details
Name: | us-gaap_RealEstateInvestmentPropertyAtCost
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of real estate investment property, net of accumulated depreciation, which may include the following: (1) land available-for-sale; (2) land available-for-development; (3) investments in building and building improvements; (4) tenant allowances; (5) developments in-process; (6) rental properties; and (7) other real estate investments. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03.1(d)) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 + Details
Name: | us-gaap_RealEstateInvestmentPropertyNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_DebtInstrumentAxis=snh_BondsPayableMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=snh_Mortgage4.38PercentDueSeptember2043Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=snh_Mortgage5.64PercentDueJanuary2016Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=snh_Mortgage5.65PercentDueJune2015Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=snh_Mortgage5.66PercentDueJuly2015Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=snh_Mortgage5.81PercentDueOctober2015Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=snh_Mortgage5.81PercentDueOctober2015TwoMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=snh_Mortgage5.83PercentDueJune2014Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=snh_Mortgage5.86PercentDueMarch2017Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=snh_Mortgage5.88PercentDueJuly2015Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=snh_Mortgage5.92PercentDueNovember2016Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=snh_Mortgage5.97PercentDueApril2016Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=snh_Mortgage6.15PercentDueAugust2017Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=snh_Mortgage6.25PercentDueFebruary2033Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=snh_Mortgage6.25PercentDueMay2015Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=snh_Mortgage6.25PercentDueNovember2016Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=snh_Mortgage6.37PercentDueJuly2015Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=snh_Mortgage6.71PercentDueSept2019Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=snh_Mortgage6.73PercentDueApril2018Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=snh_Mortgage7.31PercentAnd7.85PercentDueJan2022Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=snh_Mortgage7.31PercentDueJan2022Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=snh_Mortgage7.85PercentDueJan2022Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=snh_Mortgages5.95PercentDueAugust2037Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=snh_Mortgages6.015PercentDueMarch2015Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=snh_Mortgages6.28PercentDueJuly2022Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=snh_Mortgages6.54PercentDueMay2017Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=snh_SeniorUnsecuredNotes3.25PercentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=snh_SeniorUnsecuredNotes4.30PercentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=snh_SeniorUnsecuredNotes4.75PercentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=snh_SeniorUnsecuredNotes5.625PercentDue2042Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=snh_SeniorUnsecuredNotes6.75PercentDue2021Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=snh_SeniorUnsecuredNotes6.75PercentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=us-gaap_CapitalLeaseObligationsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=us-gaap_SecuredDebtMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=us-gaap_UnsecuredDebtMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |