Number Of Living Units

No definition available.

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Balance Type:	na
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- Definition

The number of real estate properties owned by the entity, which are classified as held for sale as of the balance sheet date.

+ References

No definition available.

+ Details

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

- Definition

Number of Real Estate Properties Sold

+ References

No definition available.

+ Details

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

- Definition

This element represents the aggregate sales price excluding closing costs, of real estate properties sold by the entity.

+ References

No definition available.

+ Details

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

- Definition

Represents the area of the real estate property sold.

+ References

No definition available.

+ Details

Name:	dhc_SquareFootageOfPropertiesSold
Namespace Prefix:	dhc_
Data Type:	num:areaItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3602-108585

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-Section 45
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-URI http://asc.fasb.org/extlink&oid=109226348&loc=d3e2420-110228

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

- Definition

Amount before tax of gain (loss) recognized on the sale or disposal of a disposal group. Excludes discontinued operations.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=109226348&loc=d3e2443-110228

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
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-Section 45
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-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3602-108585

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=109226691&loc=d3e2941-110230

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Carrying amount as of the balance sheet date of investments in land and buildings held for sale, excluding real estate considered to be inventory of the entity.

+ 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
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-URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910

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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

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Real Estate Properties - Schedule of Real Estate Properties (Details) $ in Thousands	1 Months Ended								3 Months Ended			9 Months Ended
	Sep. 30, 2020 USD ($) building living_unit	Aug. 31, 2020 USD ($) building living_unit	Jul. 31, 2020 USD ($) ft² building	Jun. 30, 2020 USD ($) ft² building	Apr. 30, 2020 USD ($) living_unit building	Mar. 31, 2020 USD ($) ft² building	Feb. 29, 2020 USD ($) ft² building	Jan. 31, 2020 USD ($) ft² building	Sep. 30, 2020 USD ($)	Mar. 31, 2020 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($) building	Sep. 30, 2019 USD ($)	Sep. 30, 2020 property	Sep. 30, 2020 building
Real Estate [Line Items]
Impairment of Assets									$ 64,202		$ 33,099	$ 106,611	$ 41,518
Disposed of by Sale, Not Discontinued Operations
Real Estate [Line Items]
Number of real estate properties sold \| building												17
Gain (loss) on Sale												$ 2,403
Impairment of Assets												8,813
Disposed of by Sale, Not Discontinued Operations \| Medical Office Buildings \| Louisiana
Real Estate [Line Items]
Number of real estate properties sold \| building								6
Square Feet \| ft²								40,575
Sales Price								$ 5,925
Gain (loss) on Sale								(81)
Impairment of Assets								$ 0
Disposed of by Sale, Not Discontinued Operations \| Medical Office Buildings \| Pennsylvania
Real Estate [Line Items]
Number of real estate properties sold \| building							1
Square Feet \| ft²							50,000
Sales Price							$ 2,900
Gain (loss) on Sale							0
Impairment of Assets							$ (47)
Disposed of by Sale, Not Discontinued Operations \| Medical Office Buildings \| Texas
Real Estate [Line Items]
Number of real estate properties sold \| building			1			1
Square Feet \| ft²			6,849			70,229
Sales Price			$ 2,072			$ 8,779
Gain (loss) on Sale			(30)			2,863
Impairment of Assets			$ 0			$ 0
Disposed of by Sale, Not Discontinued Operations \| Medical Office Buildings \| South Carolina
Real Estate [Line Items]
Number of real estate properties sold \| building				1
Square Feet \| ft²				49,242
Sales Price				$ 3,550
Gain (loss) on Sale				0
Impairment of Assets				$ 2,753
Disposed of by Sale, Not Discontinued Operations \| Medical Office Buildings \| Connecticut
Real Estate [Line Items]
Number of real estate properties sold \| building			1
Square Feet \| ft²			32,162
Sales Price			$ 625
Gain (loss) on Sale			(25)
Impairment of Assets			$ 267
Disposed of by Sale, Not Discontinued Operations \| Senior Living Communities \| California
Real Estate [Line Items]
Number of real estate properties sold \| building					3
Number of Units \| living_unit					599
Sales Price					$ 47,000
Gain (loss) on Sale					(168)
Impairment of Assets					$ 5,465
Disposed of by Sale, Not Discontinued Operations \| Senior Living Communities \| Mississippi
Real Estate [Line Items]
Number of real estate properties sold \| building	1	2
Number of Units \| living_unit	78,747	116
Sales Price	$ 7,250	$ 2,500
Gain (loss) on Sale	(114)	(42)
Impairment of Assets	148	$ 227
Held-for-sale
Real Estate [Line Items]
Sales Price												80,601
Impairment of Assets												34,880
Number of real estate properties held for sale														22	22
Gross Book Value	165,791								165,791			165,791
Held-for-sale \| Medical Office Buildings
Real Estate [Line Items]
Impairment of Assets										$ 3,071		1,524
Number of real estate properties held for sale \| building															5
Gross Book Value	69,230								69,230			69,230
Held-for-sale \| Senior Living Communities
Real Estate [Line Items]
Impairment of Assets												33,356
Number of real estate properties held for sale \| building															14
Gross Book Value	52,958								52,958			52,958
Held-for-sale \| Triple Net Leased Senior Living Communities
Real Estate [Line Items]
Impairment of Assets												0
Number of real estate properties held for sale \| building															3
Gross Book Value	$ 43,603								$ 43,603			$ 43,603