Represents the number of real estate properties serving as a collateral for debt, as of the balance sheet date.

No definition available.

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- 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 and amount equal to the present value (the principal) at the beginning of the lease term of minimum lease payments during the lease term (excluding that portion of the payments representing executory costs such as insurance, maintenance, and taxes to be paid by the lessor, together with any profit thereon) net of payments or other amounts applied to the principal through the balance sheet date.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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

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Period Type:	duration

- 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
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

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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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- 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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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount, before accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=119993939&loc=d3e28555-108399

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the 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
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
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-SubTopic 210
-Section S99
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-Name Accounting Standards Codification
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-Paragraph 1
-Subparagraph (SX 210.7-03(16))
-URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910

+ Details

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

- Definition

The parent entity's interest in net assets of the subsidiary, expressed as a percentage.

+ References

No definition available.

+ Details

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Data Type:	num:percentItemType
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

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Balance Type:	debit
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- Details

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Name:	us-gaap_DebtInstrumentAxis=dhc_Mortgages6.28PercentDueJuly2022Member
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Indebtedness - Schedule of Secured and Other Debt (Details)	1 Months Ended
	Jan. 31, 2021 USD ($)	Feb. 22, 2021 USD ($)	Dec. 31, 2020 USD ($) property	Dec. 31, 2019 USD ($)
Debt Instrument
Principal Balance			$ 691,573,000	$ 694,739,000
Net Book Value of Collateral			5,715,829,000	5,890,785,000
Unsecured revolving credit facility			0	537,500,000
Revolving Credit Facility
Debt Instrument
Deb issuance costs			19,332,000	17,170,000
Unsecured Revolving Credit Facility
Debt Instrument
Unsecured revolving credit facility			0
Subsequent Event \| Unsecured Revolving Credit Facility
Debt Instrument
Unsecured revolving credit facility		$ 0
Subsequent Event \| Unsecured Revolving Credit Facility \| Revolving Credit Facility \| LIBOR
Debt Instrument
Debt Instrument, Basis Spread on Variable Rate	0.30%
Subsequent Event \| Senior Unsecured Notes Due 2021
Debt Instrument
Principal amount of debt	$ 300,000,000
Subsequent Event \| Senior Unsecured Notes Due Feb 2021 \| LIBOR
Debt Instrument
Principal amount of debt	$ 200,000,000
Secured Debt
Debt Instrument
Principal Balance			$ 692,294,000	698,235,000
Number of Properties as Collateral \| property			9
Net Book Value of Collateral			$ 822,153,000	859,004,000
Deb issuance costs			25,000
Secured Debt \| Mortgage notes 7.49% maturing in January 2022
Debt Instrument
Principal Balance			$ 0	1,426,000
Interest rate (as a percent)			7.49%
Number of Properties as Collateral \| property			0
Net Book Value of Collateral			$ 0	11,469,000
Deb issuance costs			721,000	506,000
Debt issuance costs, net				25,000
Secured Debt \| Mortgage notes 6.28% maturing July 2022
Debt Instrument
Principal Balance			$ 11,838,000	12,513,000
Interest rate (as a percent)			6.28%
Number of Properties as Collateral \| property			1
Net Book Value of Collateral			$ 23,500,000	23,662,000
Secured Debt \| Mortgage notes 4.85% maturing October 2022
Debt Instrument
Principal Balance			$ 10,724,000	10,958,000
Interest rate (as a percent)			4.85%
Number of Properties as Collateral \| property			1
Net Book Value of Collateral			$ 19,675,000	20,139,000
Secured Debt \| Mortgage notes 5.75% maturing October 2022
Debt Instrument
Principal Balance			$ 15,805,000	16,131,000
Interest rate (as a percent)			5.75%
Number of Properties as Collateral \| property			2
Net Book Value of Collateral			$ 19,180,000	19,751,000
Secured Debt \| Mortgage notes 6.64% maturing June 2023
Debt Instrument
Principal Balance			$ 15,646,000	16,056,000
Interest rate (as a percent)			6.64%
Number of Properties as Collateral \| property			1
Net Book Value of Collateral			$ 23,023,000	22,854,000
Secured Debt \| Mortgage notes 3.53% maturing in August 2026
Debt Instrument
Principal Balance			$ 620,000,000	620,000,000
Interest rate (as a percent)			3.53%
Number of Properties as Collateral \| property			1
Net Book Value of Collateral			$ 705,096,000	724,715,000
Secured Debt \| Mortgage notes 6.25% maturing in March 2026
Debt Instrument
Principal Balance			$ 0	1,589,000
Interest rate (as a percent)			6.25%
Number of Properties as Collateral \| property			0
Net Book Value of Collateral			$ 0	4,226,000
Secured Debt \| Mortgage notes 4.44% maturing July 2043
Debt Instrument
Principal Balance			$ 10,470,000	10,688,000
Interest rate (as a percent)			4.44%
Number of Properties as Collateral \| property			1
Net Book Value of Collateral			$ 13,582,000	13,756,000
Secured Debt \| Capital leases 7.70% maturing in April 2026
Debt Instrument
Principal Balance			$ 7,811,000	8,874,000
Interest rate (as a percent)			7.70%
Number of Properties as Collateral \| property			2
Net Book Value of Collateral			$ 18,097,000	$ 18,432,000
Joint Venture
Debt Instrument
Ownership interest by parent			55.00%
Joint Venture \| Secured Debt \| Mortgage notes 3.53% maturing in August 2026
Debt Instrument
Ownership interest by parent			55.00%