Name:	denn_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsCancellationsWeightedAverageGrantDateFairValue
Namespace Prefix:	denn_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

Share Based Compensation Arrangement By Share Based Payment Award, Equity Instruments Other Than Options, Reissuance, Weighted Average Grant Date Fair Value

No definition available.

Name:	denn_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsReissuanceWeightedAverageGrantDateFairValue
Namespace Prefix:	denn_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

Share Based Compensation Arrangement By Share Based Payment Award, Non Option Equity Instruments, Cancellations Due To Modification

No definition available.

Name:	denn_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsCancellationsDueToModification
Namespace Prefix:	denn_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

Share Based Compensation Arrangement By Share Based Payment Award, Non Option Equity Instruments, Reissuance Due To Modification

No definition available.

Name:	denn_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsReissuanceDueToModification
Namespace Prefix:	denn_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

The weighted average fair value of awards on equity-based plans excluding option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, revenue or profit achievement stock award plan) for which the employer is contingently obligated to issue equity instruments or transfer assets to an employee. Includes vested and nonvested awards.

No definition available.

Name:	denn_SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsOtherthanOptionsWeightedAverageGrantDateFairValue
Namespace Prefix:	denn_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

Number of equity instruments other than options outstanding, vested

No definition available.

Name:	denn_SharebasedCompensationArrangementbySharebasedPaymentAwardNonOptionEquityInstrumentsVestedNumber
Namespace Prefix:	denn_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

The weighted average fair value of equity instruments other than options outstanding, vested

No definition available.

Name:	denn_SharebasedCompensationArrangementbySharebasedPaymentAwardNonOptionEquityInstrumentsVestedWeightedAverageGrantDateFairValue
Namespace Prefix:	denn_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event.

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

No definition available.

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

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

No definition available.

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

The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

Number of non-option equity instruments exercised by participants.

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExercised
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

Number of shares under non-option equity instrument agreements that were cancelled as a result of occurrence of a terminating event.

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsForfeitures
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

Net number of non-option equity instruments granted to participants.

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsGranted
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

Number of equity instruments other than options outstanding, including both vested and non-vested instruments.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(ii)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(i)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901