Real Estate and Other Investments - Schedule of Equity Method Investments in Unconsolidated Joint Ventures (Details) $ in Thousands	Dec. 31, 2025 USD ($) ft² property	Dec. 31, 2024 USD ($)
Real Estate
DHC Carrying Value of Investment \| $	$ 120,126	$ 126,859
Number of Properties \| property	298
Corporate Joint Venture
Real Estate
DHC Carrying Value of Investment \| $	$ 120,126
Number of Properties \| property	11
Area of real estate properties (in square feet) \| ft²	2,203,242
Seaport Innovation LLC \| Corporate Joint Venture
Real Estate
DHC Ownership	10.00%
DHC Carrying Value of Investment \| $	$ 73,471
Number of Properties \| property	1
Area of real estate properties (in square feet) \| ft²	1,134,479
The LSMD Fund REIT LLC \| Corporate Joint Venture
Real Estate
DHC Ownership	20.00%
DHC Carrying Value of Investment \| $	$ 46,655
Number of Properties \| property	10
Area of real estate properties (in square feet) \| ft²	1,068,763

Area of a real estate property.

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- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 28
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482907/825-10-50-28

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 323
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481687/323-10-50-3

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- Definition

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

+ References

No definition available.

+ Details

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- Definition

The carrying amount of investments in unconsolidated real estate and other joint ventures not separately presented. This includes direct and indirect investments.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 944
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(1)(d))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478777/944-210-S99-1

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 944
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(1)(6))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478777/944-210-S99-1

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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

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 976
-SubTopic 310
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477332/976-310-50-1

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