XML 55 R54.htm IDEA: XBRL DOCUMENT
v3.19.3.a.u2

Indebtedness - Narrative (Details) | 1 Months Ended | 9 Months Ended | 12 Months Ended |  |  |  |  |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Feb. 29, 2020 USD ($) community | May 31, 2019 USD ($) community | Jun. 30, 2018 USD ($) | Mar. 31, 2018 USD ($) | Feb. 28, 2018 USD ($) property | Sep. 30, 2019 USD ($) | Dec. 31, 2019 USD ($) | Dec. 31, 2018 USD ($) property | Dec. 31, 2017 USD ($) property | Feb. 28, 2020 USD ($) | Sep. 30, 2018 USD ($) property | Jul. 31, 2018 USD ($) property | Jan. 31, 2018 USD ($) property | May 31, 2017 USD ($) property | Apr. 30, 2017 USD ($) property | Mar. 31, 2017
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Mortgage debt assumed |  |  |  |  |  |  | $ 0 | $ 44,386,000 | $ 0 |  |  |  |  |  |  |
Unsecured revolving credit facility |  |  |  |  |  |  | 537,500,000 | 139,000,000 |  |  |  |  |  |  |  |
Loss on early extinguishment of debt |  |  |  |  |  |  | 44,000 | $ 22,000 | $ 7,627,000 |  |  |  |  |  |  |
Unsecured Revolving Credit Facility |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Unsecured revolving credit facility, maximum borrowing capacity |  |  |  |  |  |  | 1,000,000,000 |  |  |  |  |  |  |  |  |
Maximum borrowing capacity that may be increased |  |  |  |  |  |  | $ 2,000,000,000 |  |  |  |  |  |  |  |  |
Revolving credit facility, interest rate payable (as a percent) |  |  |  |  |  |  | 2.80% |  |  |  |  |  |  |  |  |
Weighted average interest rate on debt (as a percent) |  |  |  |  |  |  | 3.40% | 3.00% | 2.40% |  |  |  |  |  |  |
Unsecured revolving credit facility |  |  |  |  |  |  | $ 537,500,000 |  |  |  |  |  |  |  |  |
Revolving credit facility, available amount |  |  |  |  |  |  | 462,500,000 |  |  |  |  |  |  |  |  |
Unsecured Revolving Credit Facility | Forecast |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Unsecured revolving credit facility |  |  |  |  |  |  |  |  |  | $ 593,000,000 |  |  |  |  |  |
Revolving credit facility, available amount |  |  |  |  |  |  |  |  |  | $ 407,000,000 |  |  |  |  |  |
Senior unsecured notes due 2019 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Interest rate (as a percent) |  | 325.00% |  |  |  |  |  |  |  |  |  |  |  |  |  |
Loss on early extinguishment of debt |  |  |  |  |  | $ 17,000 |  |  |  |  |  |  |  |  |  |
Debt extinguishment, amount |  | $ 400,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt extinguishment, accrued and interest payable |  | 6,500,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Senior Unsecured Note Due July 2019 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Principal amount of debt |  | $ 42,211,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Interest rate (as a percent) |  | 3.79% |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of communities | community |  | 4 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Senior unsecured notes due 2028 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Principal amount of debt |  |  |  |  | $ 500,000 |  |  |  |  |  |  |  |  |  |  |
Interest rate (as a percent) |  |  |  |  | 4.75% |  |  |  |  |  |  |  |  |  |  |
Unsecured Notes Due June 2023 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Interest rate (as a percent) |  |  |  |  | 6.64% |  |  |  |  |  |  |  |  |  |  |
Mortgage debt assumed |  |  |  |  | $ 16,748,000 |  |  |  |  |  |  |  |  |  |  |
Unsecured Notes Due June 2023 | Senior Living Communities |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of properties mortgaged | property |  |  |  |  | 1 |  |  |  |  |  |  |  |  |  |  |
Unsecured Notes Due July 2043 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Interest rate (as a percent) |  |  |  |  |  |  |  | 4.44% |  |  |  |  |  |  |  |
Mortgage debt assumed |  |  |  | $ 11,050,000 |  |  |  |  |  |  |  |  |  |  |  |
Unsecured Notes Due July 2043 | Office Portfolio |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of properties mortgaged | property |  |  |  |  |  |  |  | 1 |  |  |  |  |  |  |  |
Senior Notes Due October 2022 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Interest rate (as a percent) |  |  |  |  |  |  |  | 5.75% |  |  |  |  |  |  |  |
Mortgage debt assumed |  |  | $ 16,588,000 |  |  |  |  |  |  |  |  |  |  |  |  |
Senior Notes Due October 2022 | Senior Living Communities |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of properties mortgaged | property |  |  |  |  |  |  |  | 2 |  |  |  |  |  |  |  |
Term loan due 2020 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Principal amount of debt |  |  |  |  |  |  | $ 250,000,000 |  |  |  |  |  |  |  |  |
Interest rate (as a percent) |  |  |  |  |  |  | 2.90% |  |  |  |  |  |  |  |  |
Weighted average annual interest rate (as a percent) |  |  |  |  |  |  | 2.90% |  |  |  |  |  |  |  |  |
Loss on early extinguishment of debt |  |  |  |  |  |  | $ 27,000 |  |  |  |  |  |  |  |  |
Term loan due 2020 | LIBOR |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Basis points per annum (as a percent) |  |  |  |  |  |  | 1.25% |  |  |  |  |  |  |  |  |
Unsecured term loan due January 2020 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Principal amount of debt |  |  |  |  |  |  | $ 350,000,000 |  |  |  |  |  |  |  |  |
Term loan due 2022 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Principal amount of debt |  |  |  |  |  |  | $ 200,000,000 |  |  |  |  |  |  |  |  |
Interest rate (as a percent) |  |  |  |  |  |  | 3.20% |  |  |  |  |  |  |  |  |
Weighted average annual interest rate (as a percent) |  |  |  |  |  |  | 3.70% |  |  |  |  |  |  |  |  |
Maximum borrowing capacity that may be increased |  |  |  |  |  |  | $ 400,000,000 |  |  |  |  |  |  |  |  |
Weighted average interest rate on debt (as a percent) |  |  |  |  |  |  |  | 3.40% | 2.70% |  |  |  |  |  |  |
Term loan due 2022 | LIBOR |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Basis points per annum (as a percent) |  |  |  |  |  |  | 1.35% |  |  |  |  |  |  |  |  |
Mortgage maturing in September 2043 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Interest rate (as a percent) |  |  |  |  |  |  |  |  |  |  |  |  | 4.40% |  |  |
Secured debt |  |  |  |  |  |  |  |  |  |  |  |  | $ 4,338,000 |  |  |
Number of properties mortgaged | property |  |  |  |  |  |  |  |  |  |  |  |  | 1 |  |  |
Senior Unsecured Notes Due October 2018 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Principal amount of debt |  |  |  |  |  |  |  |  |  |  |  | $ 90,602,000 |  |  |  |
Number of properties mortgaged | property |  |  |  |  |  |  |  |  |  |  |  | 12 |  |  |  |
Weighted average interest rate on debt (as a percent) |  |  |  |  |  |  |  |  |  |  |  | 5.00% |  |  |  |
Senior Unsecured Notes Due January 2019 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Principal amount of debt |  |  |  |  |  |  |  |  |  |  | $ 6,325,000 |  |  |  |  |
Interest rate (as a percent) |  |  |  |  |  |  |  |  |  |  | 4.70% |  |  |  |  |
Number of properties mortgaged | property |  |  |  |  |  |  |  |  |  |  | 1 |  |  |  |  |
Loss on early extinguishment of debt |  |  |  |  |  |  |  | $ 22,000 |  |  |  |  |  |  |  |
Senior Unsecured Notes Due September 2019 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Principal amount of debt |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 5,449,000 |
Interest rate (as a percent) |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 6.71% |
Secured debt |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 277,837,000 |
Number of properties mortgaged | property |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 17 |
Senior Unsecured Notes Due August 2017 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Interest rate (as a percent) |  |  |  |  |  |  |  |  |  |  |  |  |  | 6.15% |  |
Secured debt |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 10,579,000 |  |
Number of properties mortgaged | property |  |  |  |  |  |  |  |  |  |  |  |  |  | 1 |  |
Senior Unsecured Notes Due August 2037 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Interest rate (as a percent) |  |  |  |  |  |  |  | 5.95% |  |  |  |  |  |  |  |
Secured debt |  |  |  |  |  |  |  | $ 8,807,000 |  |  |  |  |  |  |  |
Number of properties mortgaged | property |  |  |  |  |  |  |  | 1 |  |  |  |  |  |  |  |
Senior Unsecured Notes Due April 2018 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Interest rate (as a percent) |  |  |  |  |  |  |  |  | 6.73% |  |  |  |  |  |  |
Secured debt |  |  |  |  |  |  |  |  | $ 8,403,000 |  |  |  |  |  |  |
Number of properties mortgaged | property |  |  |  |  |  |  |  |  | 1 |  |  |  |  |  |  |
Loss on early extinguishment of debt |  |  |  |  |  |  |  |  | $ 7,627,000 |  |  |  |  |  |  |
Revolving Credit Facility | Unsecured Revolving Credit Facility | LIBOR |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Basis points per annum (as a percent) |  |  |  |  |  |  | 1.20% |  |  |  |  |  |  |  |  |
Loan commitment fee percentage |  |  |  |  |  |  | 0.25% |  |  |  |  |  |  |  |  |
Joint Venture |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Ownership interest by parent |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 55.00%
Subsequent Event | Senior Unsecured Notes Due March 2026 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Principal amount of debt | $ 1,554,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Interest rate (as a percent) | 6.25% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of communities | community | 1 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |

X
- Definition Represents the maximum borrowing capacity to which loan may be expanded per the terms of the agreement, at the option of the reporting entity. + References No definition available. + Details
Name: | dhc_DebtInstrumentMaximumBorrowingCapacityOptionToIncrease
Namespace Prefix: | dhc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Weighted average interest rate on debt during the period. + References No definition available. + Details
Name: | dhc_DebtWeightedAverageInterestRateDuringThePeriod
Namespace Prefix: | dhc_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Extinguishment Of Debt, Accrued And Interest Payable + References No definition available. + Details
Name: | dhc_ExtinguishmentOfDebtAccruedAndInterestPayable
Namespace Prefix: | dhc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Represents the number of communities. + References No definition available. + Details
Name: | dhc_NumberOfCommunities
Namespace Prefix: | dhc_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the number of real estate properties serving as a collateral for debt, as of the balance sheet date. + References No definition available. + Details
Name: | dhc_NumberOfRealEstatePropertiesCollateralized
Namespace Prefix: | dhc_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- 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: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- 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 -URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28551-108399 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 55 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400 + Details
Name: | us-gaap_DebtInstrumentFaceAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Contractual interest rate for funds borrowed, under the debt 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 -Subparagraph (SX 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

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

X
- Definition Weighted average interest rate of debt outstanding. + References No definition available. + Details
Name: | us-gaap_DebtWeightedAverageInterestRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Gross amount of debt extinguished. + References No definition available. + Details
Name: | us-gaap_ExtinguishmentOfDebtAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 50 -Section 40 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=117329964&loc=d3e12355-112629 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 50 -Section 40 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=117329964&loc=d3e12317-112629 Reference 3: 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=118932676&loc=d3e3602-108585 + Details
Name: | us-gaap_GainsLossesOnExtinguishmentOfDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- 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 -Subparagraph (SX 210.5-02(22)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(16)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 3: 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(16)) -URI http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910 + Details
Name: | us-gaap_LineOfCredit
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The fee, expressed as a percentage of the line of credit facility, for the line of credit facility regardless of whether the facility has been used. + References No definition available. + Details
Name: | us-gaap_LineOfCreditFacilityCommitmentFeePercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The effective interest rate at the end of the reporting period. + 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 -Subparagraph (SX 210.5-02.19(b),22(b)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility. + 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 -Subparagraph (SX 210.5-02.19(b),22(b)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding). + 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 -Subparagraph (SX 210.5-02.19(b),22(b)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The parent entity's interest in net assets of the subsidiary, expressed as a percentage. + References No definition available. + Details
Name: | us-gaap_MinorityInterestOwnershipPercentageByParent
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- 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=98513485&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=98513485&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=98513485&loc=d3e4332-108586 + Details
Name: | us-gaap_NoncashOrPartNoncashAcquisitionDebtAssumed1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- 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 -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(16)) -URI http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(16)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(22)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_SecuredDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_DebtInstrumentAxis=us-gaap_LineOfCreditMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementScenarioAxis=srt_ScenarioForecastMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=dhc_SeniorUnsecuredNotesDue2019Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=dhc_SeniorUnsecuredNoteDueJuly2019Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=dhc_SeniorUnsecuredNotes4.75PercentDue2028Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=dhc_UnsecuredNotesDueJune2023Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis=dhc_SeniorLivingCommunityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=dhc_UnsecuredNotesDueJuly2043Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis=dhc_MedicalOfficeBuildingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=dhc_SeniorNotesDueOctober2022Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=dhc_TermLoanDue2020Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_VariableRateAxis=us-gaap_LondonInterbankOfferedRateLIBORMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=dhc_UnsecuredTermLoanDueJanuary2020Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=dhc_TermLoanDue2022Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=dhc_UnsecuredNoteDueSeptember2043Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=dhc_SeniorUnsecuredNotesDueOctober2018Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=dhc_SeniorUnsecuredNotesDueJanuary2019Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=dhc_SeniorUnsecuredNotesDueSeptember2019Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=dhc_SeniorUnsecuredNotesDueAugust2017Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=dhc_SeniorUnsecuredNotesDueAugust2037Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=dhc_SeniorUnsecuredNotesDueApril2018Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CreditFacilityAxis=us-gaap_RevolvingCreditFacilityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_OwnershipAxis=dhc_JointVentureMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=dhc_SeniorUnsecuredNoteDueMarch2026Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |