Cash Paid plus Assumed Debt, including closing costs plus other settlement adjustments

No definition available.

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Namespace Prefix:	dhc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The amount of premium on assumed debt that an Entity assumes in acquiring a business or in consideration for an asset received in a noncash (or part noncash) acquisition.

+ References

No definition available.

+ Details

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Namespace Prefix:	dhc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Represents the intangible lease assets recorded as part of the real estate acquisition.

+ References

No definition available.

+ Details

Name:	dhc_RealEstatePropertiesAcquiredIntangibleLeaseAssets
Namespace Prefix:	dhc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Represents the intangible lease liabilities recorded as part of the real estate acquisition.

+ References

No definition available.

+ Details

Name:	dhc_RealEstatePropertiesAcquiredIntangibleLeaseLiabilities
Namespace Prefix:	dhc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The amount of debt that an Entity assumes in acquiring a business or in consideration for an asset received in a noncash (or part noncash) acquisition. Noncash is defined as transactions during a period that affect recognized assets or liabilities but that do not result in cash receipts or cash payments in the period. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=123431023&loc=d3e4304-108586

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=123431023&loc=d3e4313-108586

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=123431023&loc=d3e4332-108586

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The number of real estate properties owned as of the balance sheet date.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

The number of units in a real estate property owned as of the balance sheet date.

+ References

No definition available.

+ Details

Name:	us-gaap_NumberOfUnitsInRealEstateProperty
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- 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://fasb.org/us-gaap/role/ref/legacyRef
-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=120400017&loc=d3e572229-122910

+ Details

Name:	us-gaap_RealEstateInvestmentPropertyNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- 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_RealEstateLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	srt_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis=dhc_IndependentLivingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementGeographicalAxis=stpr_TX
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis=us-gaap_SeriesOfIndividuallyImmaterialBusinessAcquisitionsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=us-gaap_LandMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=us-gaap_BuildingAndBuildingImprovementsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=dhc_FurnitureFixturesAndEquipmentMember
Namespace Prefix:
Data Type:	na
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Period Type:

Real Estate Investments - Schedule of Acquisitions (Details) $ in Thousands	1 Months Ended
	Dec. 31, 2019 USD ($) property unit	Dec. 31, 2021 USD ($) property	Dec. 31, 2020 USD ($)
Real Estate
Number of Properties \| property		390
Net book value of collateral		$ 5,075,749	$ 5,715,829
IL \| Texas \| Acquisitions
Real Estate
Number of Properties \| property	1
Number of Units \| unit	169
Cash Paid plus Assumed Debt	$ 50,506
Acquired Real Estate Leases / Resident Agreements	2,202
Acquired Real Estate Lease Obligations	0
Assumed Debt	0
Premium on Assumed Debt	0
Land
Real Estate
Net book value of collateral		741,501	789,125
Land \| IL \| Texas \| Acquisitions
Real Estate
Net book value of collateral	3,463
Buildings and Improvements
Real Estate
Net book value of collateral		$ 6,072,055	$ 6,621,605
Buildings and Improvements \| IL \| Texas \| Acquisitions
Real Estate
Net book value of collateral	44,189
FF&E \| IL \| Texas \| Acquisitions
Real Estate
Net book value of collateral	$ 652