XML 68 R51.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Indebtedness - Schedule of Outstanding Debts (Details) - USD ($) | Dec. 31, 2018 | Feb. 28, 2018 | Dec. 31, 2017 | Feb. 29, 2016
--- | --- | --- | --- | ---
Debt Instrument [Line Items] |  |  |  |
Face Amount | $ 2,250,000,000 |  | $ 1,750,000,000 |
Unamortized Discount | $ 9,974,000 |  | 3,159,000 |
Senior unsecured notes due 2019 |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Coupon | 3.25% |  |  |
Face Amount | $ 400,000,000 |  | 400,000,000 |
Unamortized Discount | $ 19,000 |  | 78,000 |
Senior unsecured notes due 2020 |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Coupon | 6.75% |  |  |
Face Amount | $ 200,000,000 |  | 200,000,000 |
Unamortized Discount | $ 274,000 |  | 488,000 |
Unsecured senior notes due 2021 |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Coupon | 6.75% |  |  |
Face Amount | $ 300,000,000 |  | 300,000,000 |
Unamortized Discount | $ 1,558,000 |  | 2,093,000 |
Senior unsecured notes due 2024 |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Coupon | 4.75% |  |  |
Face Amount | $ 250,000,000 |  | 250,000,000 |
Unamortized Discount | $ 421,000 |  | 500,000 |
Senior Unsecured Notes Due 2028 |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Coupon | 4.75% | 4.75% |  |
Face Amount | $ 500,000,000 | $ 500,000,000 | 0 |
Unamortized Discount | $ 7,702,000 |  | 0 |
Senior unsecured notes due in 2042 |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Coupon | 5.625% |  |  |
Face Amount | $ 350,000,000 |  | 350,000,000 |
Unamortized Discount | $ 0 |  | 0 |
Senior unsecured notes due in 2046 |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Coupon | 6.25% |  |  | 6.25%
Face Amount | $ 250,000,000 |  | 250,000,000 | $ 250,000,000
Unamortized Discount | $ 0 |  | $ 0 |

X
- Definition Face (par) amount of debt instrument at time of issuance. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28551-108399 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 55 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=114775985&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://fasb.org/us-gaap/role/ref/legacyRef -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
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount, after accumulated amortization, of debt discount. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 1A -URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28541-108399 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 55 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400 + Details
Name: | us-gaap_DebtInstrumentUnamortizedDiscount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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_SeniorUnsecuredNotes6.75PercentMember
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_SeniorUnsecuredNotes4.75PercentDue2024Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=snh_SeniorUnsecuredNotes4.75PercentDue2028Member
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_SeniorUnsecuredNotes6.25DueIn2046Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |