Represents the number of properties sold during the period, not categorized as discontinued operations.

No definition available.

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- Definition

Loans And Leases Receivable, Purchase Option, Number Of Properties

+ References

No definition available.

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- Definition

The gross carrying amount of loans receivable that are subordinated to receivables held by other entities.

+ References

No definition available.

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- Definition

The number of loans to VIE borrowers.

+ References

No definition available.

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- Definition

Represents number of unconsolidated joint ventures between entity and an institutional capital partner.

+ References

No definition available.

+ Details

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- Definition

The number of VIE borrowers in which the entity has invested in marketable debt securities.

+ References

No definition available.

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- Definition

Represents the period of call-option retained.

+ References

No definition available.

+ Details

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- Definition

Number of properties leased by the entity to tenants that have been identified as a VIE.

+ References

No definition available.

+ Details

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Balance Type:	na
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- Definition

Tax Benefit Of Initial Consolidation Of Variable Interest Entity

+ References

No definition available.

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Balance Type:	credit
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- Definition

Number of tenants of properties leased by entity for which the tenant is considered a VIE tenant.

+ References

No definition available.

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Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the number of controlling ownership interest entities, in which the company holds the interest and is the managing member of the partnership.

+ References

No definition available.

+ Details

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Data Type:	xbrli:integerItemType
Balance Type:	na
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- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

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- Definition

Amount after allowance and deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements and loans held for sale.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
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-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.7)
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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- Definition

The carrying amount of the consolidated Variable Interest Entity's assets included in the reporting entity's statement of financial position.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (bb)
-URI http://asc.fasb.org/extlink&oid=108788376&loc=d3e5710-111685

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- Definition

The carrying amount of the consolidated Variable Interest Entity's liabilities included in the reporting entity's statement of financial position.

+ References

+ Details

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Balance Type:	credit
Period Type:	instant

- Definition

The gain (loss) recognized on initial consolidation of a variable interest entity (VIE) when the VIE is not a business (as defined).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=108788376&loc=d3e5710-111685

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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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Balance Type:	na
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- Definition

Percentage of the Variable Interest Entity's (VIE) voting interest owned by (or beneficial interest in) the reporting entity (directly or indirectly).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 5A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=108788376&loc=SL6759159-111685

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
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Period Type:	duration

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Variable Interest Entities - Narrative (Details) $ in Thousands, £ in Millions	1 Months Ended		3 Months Ended					9 Months Ended		12 Months Ended
	Aug. 31, 2018	Mar. 31, 2017 property	Jun. 30, 2018 facility	Mar. 31, 2018 USD ($)	Mar. 31, 2018 GBP (£)	Dec. 31, 2017 USD ($) facility	Sep. 30, 2017 facility	Sep. 30, 2018 USD ($) property facility joint_venture tenant loan	Sep. 30, 2017 USD ($)	Dec. 31, 2016 USD ($) property	Mar. 31, 2018 GBP (£)	Dec. 31, 2016 GBP (£) property
Variable Interest Entity [Line Items]
Mezzanine						$ 269,299		$ 21,572
Loans receivable, net						$ 313,326		41,302
Loss from initial consolidation of VIE								$ 41,017	$ 0
Senior housing triple-net
Variable Interest Entity [Line Items]
Number of properties sold		64	2			2	2
Unconsolidated Variable Interest Entities
Variable Interest Entity [Line Items]
Number of unconsolidated joint ventures \| joint_venture								4
Number of VIE borrowers with marketable debt securities \| joint_venture								1
Number of loans to VIE borrowers \| loan								1
VIE tenants-operating leases
Variable Interest Entity [Line Items]
Number of properties leased \| property								48
Number of VIE tenants \| tenant								7
CCRC OpCo
Variable Interest Entity [Line Items]
Ownership percentage (as a percent)								49.00%
Vintage Park Development JV
Variable Interest Entity [Line Items]
Ownership percentage (as a percent)								85.00%
Waldwick
Variable Interest Entity [Line Items]
Ownership percentage (as a percent)								85.00%
Loan - Seller Financing \| Senior housing triple-net
Variable Interest Entity [Line Items]
Mezzanine								$ 10,000
Number of properties sold \| facility								7
Term of facility								5 years
HCP Ventures V
Variable Interest Entity [Line Items]
Ownership percentage (as a percent)								51.00%
Vintage Park JV
Variable Interest Entity [Line Items]
Ownership percentage (as a percent)								90.00%
Watertown JV
Variable Interest Entity [Line Items]
Ownership percentage (as a percent)								95.00%
Hayden JV
Variable Interest Entity [Line Items]
Ownership percentage (as a percent)								99.00%
MSREI JV
Variable Interest Entity [Line Items]
Ownership percentage (as a percent)	51.00%							51.00%
Consolidated lessees VIE
Variable Interest Entity [Line Items]
Number of properties leased \| property								7
DownREIT Partnerships
Variable Interest Entity [Line Items]
Number of controlling ownership interest entities as a managing member \| joint_venture								5
MMCG
Variable Interest Entity [Line Items]
Loss from initial consolidation of VIE				$ 41,000	£ 29
Tax benefit of initial consolidation of variable interest entity				3,000	2
Carrying amount of liabilities in VIE				13,000							£ 9
MMCG \| Property, plant and equipment
Variable Interest Entity [Line Items]
Carrying amount of assets in VIE				114,000							81
MMCG \| Intangible assets
Variable Interest Entity [Line Items]
Carrying amount of assets in VIE				5,000							£ 4
MMCG \| Bridge Loan
Variable Interest Entity [Line Items]
Loans receivable, net										$ 131,000		£ 105
Number of properties in a purchase option \| property										7		7
Period of call-option retained										3 years
Loss from initial consolidation of VIE				$ 41,000	£ 29