Debt Instrument, Extension Option Term

No definition available.

Name:	dhc_DebtInstrumentExtensionOptionTerm
Namespace Prefix:	dhc_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Encumbered Properties

+ References

No definition available.

+ Details

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Namespace Prefix:	dhc_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Number Of Extension Options

+ References

No definition available.

+ Details

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Namespace Prefix:	dhc_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
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-Publisher FASB
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+ Details

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The number of states the entity operates in 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

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

- 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.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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-Section S99
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+ Details

Name:	us-gaap_SecuredDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

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Namespace Prefix:
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- Details

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Data Type:	na
Balance Type:
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- Details

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- Details

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- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=us-gaap_InterestRateCapMember
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Real Estate Investments - Mortgage Debt Joint Venture (Details)	3 Months Ended
	Mar. 31, 2023 USD ($) property state option	Jan. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Real Estate
Number of states in which properties are located \| state	36
Seaport Innovation LLC
Real Estate
Aggregate principal amount of mortgage debt			$ 620,000,000
Corporate Joint Venture
Real Estate
Coupon rate (percent)	4.10%
Debt face amount	$ 1,076,625,000
Aggregate principal amount of mortgage debt		$ 456,600,000
Seaport Innovation LLC \| Corporate Joint Venture \| Massachusetts
Real Estate
Encumbered properties (property) \| property	1
Coupon rate (percent)	3.53%
Debt face amount	$ 620,000,000
The LSMD Fund REIT LLC \| Corporate Joint Venture
Real Estate
Encumbered properties (property) \| property	9
Number of states in which properties are located \| state	5
Coupon rate (percent)	3.46%
Debt face amount	$ 189,800,000
The LSMD Fund REIT LLC \| Corporate Joint Venture \| California
Real Estate
Encumbered properties (property) \| property	1
Coupon rate (percent)	5.90%
Debt face amount	$ 266,825,000
Number of extension options \| option	3
Extension term	1 year
The LSMD Fund REIT LLC \| Corporate Joint Venture \| California \| SOFR
Real Estate
Basis points per annum (as a percent)	1.90%
The LSMD Fund REIT LLC \| Corporate Joint Venture \| California \| SOFR \| Interest Rate Cap
Real Estate
Basis points per annum (as a percent)	4.00%