Annual report pursuant to Section 13 and 15(d)

Summary of Significant Accounting Policies (Narrative)(Details)

v2.4.1.9
Summary of Significant Accounting Policies (Narrative)(Details) (USD $)
In Thousands, except Share data, unless otherwise specified
 12 Months Ended
Dec. 28, 2014
Dec. 29, 2013
Dec. 30, 2012
Summary of Significant Accounting Policies [Line Items]      
Number of states 13us-gaap_NumberOfStatesInWhichEntityOperates    
Number of restaurants 59us-gaap_NumberOfRestaurants 48us-gaap_NumberOfRestaurants 39us-gaap_NumberOfRestaurants
Proceeds from sale of common stock, net of underwriting fees $ 0us-gaap_ProceedsFromIssuanceOfCommonStock $ 0us-gaap_ProceedsFromIssuanceOfCommonStock $ 81,104us-gaap_ProceedsFromIssuanceOfCommonStock
Marketing expense 1,719us-gaap_MarketingExpense 1,306us-gaap_MarketingExpense 1,319us-gaap_MarketingExpense
Number of reportable segments 1us-gaap_NumberOfOperatingSegments    
Furniture and Fixtures [Member] | Minimum [Member]      
Summary of Significant Accounting Policies [Line Items]      
Estimated useful life 3 years    
Furniture and Fixtures [Member] | Maximum [Member]      
Summary of Significant Accounting Policies [Line Items]      
Estimated useful life 7 years    
Leasehold Improvements [Member] | Minimum [Member]      
Summary of Significant Accounting Policies [Line Items]      
Estimated useful life 5 years    
Leasehold Improvements [Member] | Maximum [Member]      
Summary of Significant Accounting Policies [Line Items]      
Estimated useful life 20 years    
IPO [Member]      
Summary of Significant Accounting Policies [Line Items]      
Sale of stock (in shares)   6,708,332us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction
/ us-gaap_SubsidiarySaleOfStockAxis
= us-gaap_IPOMember 		 
Proceeds from sale of common stock, net of underwriting fees   $ 78,100us-gaap_ProceedsFromIssuanceOfCommonStock
/ us-gaap_SubsidiarySaleOfStockAxis
= us-gaap_IPOMember 		[1]  
[1] Proceeds were used to repay amounts outstanding under the Old Credit Facility.