XML 61 R48.htm IDEA: XBRL DOCUMENT
v3.22.0.1

Introduction and Basis of Reporting - (Schedule of Change in Restaurants Counts) (Details) - restaurant | 12 Months Ended
--- | ---
Dec. 29, 2021 | Dec. 30, 2020 | Dec. 25, 2019
Change in Restaurants Counts [Roll Forward] |  |  |
Number of restaurants, beginning of period | 1,650 | 1,703 |
Number of restaurants, end of period | 1,640 | 1,650 | 1,703
Company-owned restaurants |  |  |
Change in Restaurants Counts [Roll Forward] |  |  |
Number of restaurants, beginning of period | 65 | 68 | 173
Units opened | 0 | 0 | 0
Units sold to franchisees | 0 | 0 | (105)
Units closed | 0 | (3) | 0
Number of restaurants, end of period | 65 | 65 | 68
Franchise |  |  |
Change in Restaurants Counts [Roll Forward] |  |  |
Number of restaurants, beginning of period | 1,585 | 1,635 | 1,536
Units opened | 20 | 20 | 30
Units purchased from Company | 0 | 0 | 105
Units closed | (30) | (70) | (36)
Number of restaurants, end of period | 1,575 | 1,585 | 1,635

X
- Definition Change in Restaurants Counts [Roll Forward] + References No definition available. + Details
Name: | denn_ChangeinRestaurantsCountsRollForward
Namespace Prefix: | denn_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number Of Restaurants, Units Closed + References No definition available. + Details
Name: | denn_NumberOfRestaurantsUnitsClosed
Namespace Prefix: | denn_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number Of Restaurants, Units Opened + References No definition available. + Details
Name: | denn_NumberOfRestaurantsUnitsOpened
Namespace Prefix: | denn_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number Of Restaurants, Units Purchased From Company + References No definition available. + Details
Name: | denn_NumberOfRestaurantsUnitsPurchasedFromCompany
Namespace Prefix: | denn_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number Of Restaurants, Units Sold to Franchisees + References No definition available. + Details
Name: | denn_NumberOfRestaurantsUnitsSoldtoFranchisees
Namespace Prefix: | denn_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the number of restaurants. + References No definition available. + Details
Name: | us-gaap_NumberOfRestaurants
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | us-gaap_FranchisorDisclosureAxis=us-gaap_EntityOperatedUnitsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FranchisorDisclosureAxis=us-gaap_FranchisedUnitsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |