Represents the period to terminate the agreement after the request of the party providing the services.

No definition available.

Name:	dde_RelatedPartyTransactionAgreementTerminationPeriodByProviderOfServices
Namespace Prefix:	dde_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the period to terminate the agreement after the request of the party receiving the services.

+ References

No definition available.

+ Details

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Namespace Prefix:	dde_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the length of the harness racing track, located on the related party's property used by the entity during its harness racing season.

+ References

No definition available.

+ Details

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Namespace Prefix:	dde_
Data Type:	num:lengthItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the percentage of voting power of the entity held by the related party of the entity.

+ References

No definition available.

+ Details

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Namespace Prefix:	dde_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the percentage of voting power of another related party held by the related party.

+ References

No definition available.

+ Details

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Namespace Prefix:	dde_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the length of the motorsports superspeedway used by the entity.

+ References

No definition available.

+ Details

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Namespace Prefix:	dde_
Data Type:	num:lengthItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the number of annual motorsports weekends for which the entity allows related party to use indoor grandstands.

+ References

No definition available.

+ Details

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

- Definition

Represents the number of companies, between which assets and liabilities are allocated as per various kind of agreements.

+ References

No definition available.

+ Details

Name:	dde_RelatedPartyTransactionNumberOfCompaniesBetweenWhichAssetsAndLiabilitiesAllocated
Namespace Prefix:	dde_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the number of business days to pay for services received after receipt of an invoice at rates agreed upon as per the agreement.

+ References

No definition available.

+ Details

Name:	dde_RelatedPartyTransactionPeriodForPaymentAgainstServicesReceived
Namespace Prefix:	dde_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the period of set up and tear down rights granted by the related party, before and after the period beginning from November 1 of each year and ending on April 30 of the following year, covered by the perpetual easement.

+ References

No definition available.

+ Details

Name:	dde_RelatedPartyTransactionPeriodForSetUpAndTearDownRights
Namespace Prefix:	dde_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of receivables due from an entity that is affiliated with the reporting entity by means of direct or indirect ownership, due within 1 year (or 1 business cycle).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39599-107864

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-Publisher FASB
-Name Accounting Standards Codification
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-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(k)(1))
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-Publisher FASB
-Name Accounting Standards Codification
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Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
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-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.3(a)(2))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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-Name Accounting Standards Codification
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-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

+ Details

Name:	us-gaap_DueFromAffiliateCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Expenses recognized resulting from transactions (excluding transactions that are eliminated in consolidated or combined financial statements) with related party.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

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

- Definition

Amount of revenue, fees and commissions earned from transactions between (a) a parent company and its subsidiaries; (b) subsidiaries of a common parent; (c) an entity and trusts for the benefit of employees, for example, but not limited to, pension and profit-sharing trusts that are managed by or under the trusteeship of the entity's management; (d) an entity and its principal, owners, management, or members of their immediate families; and (e) affiliates.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1(e))
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Related Parties
-URI http://asc.fasb.org/extlink&oid=16382449

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 946
-SubTopic 225
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-07.1(c))
-URI http://asc.fasb.org/extlink&oid=6488393&loc=d3e606610-122999

+ Details

Name:	us-gaap_RevenueFromRelatedParties
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=us-gaap_AffiliatedEntityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_TypeOfArrangementAxis=dde_VariousAgreementsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_TypeOfArrangementAxis=dde_TransitionSupportServicesAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=dde_AdministrativeAndOperatingCostAllocationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=dde_NascarEventAllocatedExpensesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=us-gaap_BoardOfDirectorsChairmanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Related Party Transactions (Details)	12 Months Ended
Related Party Transactions (Details)	Dec. 31, 2017 USD ($) item mi	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Related Party Transactions
Receivable from Dover Motorsports, Inc.	$ 7,000	$ 7,000
Dover Motorsports, Inc. (DVD)
Related Party Transactions
Harness racing track length (in miles) \| mi	0.625
Motorsports superspeedway length (in miles) \| mi	1
Period for set up and tear down rights	14 days
Number of annual motorsports weekends \| item	2
Dover Motorsports, Inc. (DVD) \| Various agreements
Related Party Transactions
Number of companies between which assets and liabilities are allocated \| item	2
Dover Motorsports, Inc. (DVD) \| Transition Support Services Agreement
Related Party Transactions
Period for payment against services received	30 days
Agreement termination period by recipient of services	90 days
Agreement termination period by provider of services	180 days
Dover Motorsports, Inc. (DVD) \| Certain administrative and operating service costs
Related Party Transactions
Due from related party	$ 1,862,000	1,952,000	$ 1,851,000
Allocations and invoicing from Dover Motorsports, Inc.	187,000	158,000	252,000
Dover Motorsports, Inc. (DVD) \| NASCAR event at Dover International Speedway
Related Party Transactions
Due from related party	903,000	876,000	836,000
Allocations and invoicing from Dover Motorsports, Inc.	224,000	200,000	$ 230,000
Receivable from Dover Motorsports, Inc.	$ 7,000	$ 7,000
Board of Directors Chairman
Related Party Transactions
Minimum percentage of voting power controlled by related party	50.00%
Minimum percentage of voting power of Gaming controlled by other related party	50.00%