Annual report pursuant to Section 13 and 15(d)

Fair Value Measurements (Details )

v2.4.1.9
Fair Value Measurements (Details ) (USD $)
In Millions, unless otherwise specified
3 Months Ended 12 Months Ended
Dec. 29, 2013
restaurant
Dec. 28, 2014
restaurant
Dec. 29, 2013
restaurant
Dec. 30, 2012
restaurant
Asset Impairment        
Number of restaurants impaired 4rrgb_NumberOfRestaurantsImpaired 3rrgb_NumberOfRestaurantsImpaired 4rrgb_NumberOfRestaurantsImpaired 4rrgb_NumberOfRestaurantsImpaired
Carrying amount        
Disclosures of Fair Value of Other Assets and Liabilities        
Credit facility 78.5us-gaap_DebtInstrumentFairValue
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_CarryingReportedAmountFairValueDisclosureMember
138.5us-gaap_DebtInstrumentFairValue
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_CarryingReportedAmountFairValueDisclosureMember
78.5us-gaap_DebtInstrumentFairValue
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_CarryingReportedAmountFairValueDisclosureMember
 
Capital lease obligations 9.3us-gaap_CapitalLeaseObligations
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_CarryingReportedAmountFairValueDisclosureMember
8.5us-gaap_CapitalLeaseObligations
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_CarryingReportedAmountFairValueDisclosureMember
9.3us-gaap_CapitalLeaseObligations
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_CarryingReportedAmountFairValueDisclosureMember
 
Fair value | Level 2        
Disclosures of Fair Value of Other Assets and Liabilities        
Credit facility 78.4us-gaap_DebtInstrumentFairValue
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_EstimateOfFairValueFairValueDisclosureMember
138.4us-gaap_DebtInstrumentFairValue
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_EstimateOfFairValueFairValueDisclosureMember
78.4us-gaap_DebtInstrumentFairValue
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_EstimateOfFairValueFairValueDisclosureMember
 
Capital lease obligations 10.9us-gaap_CapitalLeaseObligations
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_EstimateOfFairValueFairValueDisclosureMember
10.0us-gaap_CapitalLeaseObligations
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_EstimateOfFairValueFairValueDisclosureMember
10.9us-gaap_CapitalLeaseObligations
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_EstimateOfFairValueFairValueDisclosureMember
 
Other assets, net | Level 1        
Disclosures of Fair Value of Other Assets and Liabilities        
Investments in the rabbi trust 3.8rrgb_DeferredCompensationPlanAssetsFairValueDisclosure
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherNoncurrentAssetsMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
5.7rrgb_DeferredCompensationPlanAssetsFairValueDisclosure
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherNoncurrentAssetsMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
3.8rrgb_DeferredCompensationPlanAssetsFairValueDisclosure
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherNoncurrentAssetsMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member