Concentration of Credit Risk - Narrative (Details)	9 Months Ended	12 Months Ended
Sep. 30, 2018 facility renewal	Dec. 31, 2017
Brookdale \| Minimum
Concentration Risk [Line Items]
Percentage of EDITDAR payable as base management fee	4.50%
Brookdale \| Maximum
Concentration Risk [Line Items]
Percentage of EDITDAR payable as base management fee	5.00%
SHOP \| Management and Accounting Services \| Brookdale
Concentration Risk [Line Items]
Number of facilities \| facility	43
Number of facilities owned by unconsolidated joint venture \| facility	16
Management and Accounting Services \| SHOP \| Brookdale
Concentration Risk [Line Items]
Management agreement renewal term (in years)	5 years
Management and Accounting Services \| SHOP \| Brookdale \| Minimum
Concentration Risk [Line Items]
Management agreement term (in years)	10 years
Number of renewals on management agreement \| renewal	3
Management and Accounting Services \| SHOP \| Brookdale \| Maximum
Concentration Risk [Line Items]
Management agreement term (in years)	15 years
Number of renewals on management agreement \| renewal	4
Total Assets \| SHOP \| Brookdale
Concentration Risk [Line Items]
Concentration risk (as a percent)	7.00%	13.00%
Brookdale \| Total Assets
Concentration Risk [Line Items]
Concentration risk (as a percent)	8.00%	10.00%

The number of renewals available under the management agreement.

No definition available.

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- Definition

Represents the term of renewals of the agreement under which the Company receives management and accounting services.

+ References

No definition available.

+ Details

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- Definition

Represents the term of the agreement under which the Company receives management and accounting services.

+ References

No definition available.

+ Details

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- Definition

Represents the percentage of EBITDAR that is payable by the entity as base management fee.

+ References

No definition available.

+ Details

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- Definition

Represents the total number of facilities.

+ References

No definition available.

+ Details

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- Definition

Number of Facilities Owned by Unconsolidated Joint Venture

+ References

No definition available.

+ Details

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- 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

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- Definition

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 18
-URI http://asc.fasb.org/extlink&oid=99393423&loc=d3e6351-108592

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=109250915&loc=d3e13531-108611

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 21
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109250915&loc=d3e13537-108611

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=99393423&loc=d3e6404-108592

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