Defined Contribution Plan, Maximum Amount of Incentive Compensation Deferred, Percent

No definition available.

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- Definition

The amount of the cost recognized during the period for defined contribution plans.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 70

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6414718&loc=d3e28014-114942

+ Details

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Balance Type:	debit
Period Type:	duration

- Details

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- Definition

Percentage of employees' gross pay for which the employer contributes a matching contribution to a defined contribution plan.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum percentage of employee gross pay the employee may contribute to a defined contribution plan.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
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- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

Name:	us-gaap_PlanNameAxis=denn_NonqualifieddeferredcompensationplanMember
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Employee Benefit Plans (Defined Contribution Plans) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 25, 2013	Dec. 26, 2012
Defined Contribution Plan Disclosure [Line Items]
Employer contributions	$ 1.4	$ 1.4	$ 1.3
Defined contribution 401(k) plan [Member]
Defined Contribution Plan Disclosure [Line Items]
Maximum annual contribution per employee	25.00%
Employer matching contribution	3.00%
Non-qualified deferred compensation plan [Member]
Defined Contribution Plan Disclosure [Line Items]
Maximum annual contribution per employee	50.00%
Maximum incentive compensation deferral	100.00%
Employer matching contribution	3.00%