v2.4.1.9
Income Taxes - Additional Information (Detail)
12 Months Ended
Dec. 27, 2014
Dec. 28, 2013
Income Tax Disclosure [Abstract]    
Effective tax rate 36.50%us-gaap_EffectiveIncomeTaxRateContinuingOperations 39.33%us-gaap_EffectiveIncomeTaxRateContinuingOperations
Period to assess/collect taxes 3 years  
Percentage of understated income taxes required for extension of limitation of statute, minimum 25.00%dvly_PercentageOfUnderstatedTaxRequiredForExtensionOfLimitationOfStatuteMinimum  
Period for statute of limitations 6 years