v2.4.1.9
Summary of Significant Accounting Policies - Computation of Net Loss Per Share (Detail) (USD $)
3 Months Ended 12 Months Ended
Dec. 27, 2014
Dec. 28, 2013
Dec. 27, 2014
Dec. 28, 2013
Regulatory Assets [Abstract]        
Income attributable to common shareholders     $ 651,139dvly_IncomeAttributableToCommonShareholders $ 815,233dvly_IncomeAttributableToCommonShareholders
Weighted average shares outstanding:        
Basic 15,436,518us-gaap_WeightedAverageNumberOfSharesOutstandingBasic 15,493,116us-gaap_WeightedAverageNumberOfSharesOutstandingBasic 15,436,518us-gaap_WeightedAverageNumberOfSharesOutstandingBasic 15,493,116us-gaap_WeightedAverageNumberOfSharesOutstandingBasic
Diluted 15,436,518us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding 15,493,116us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding 15,436,518us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding 15,493,116us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding
Income per share:        
Basic     $ 0.04us-gaap_EarningsPerShareBasic $ 0.05us-gaap_EarningsPerShareBasic
Diluted     $ 0.04us-gaap_EarningsPerShareDiluted $ 0.05us-gaap_EarningsPerShareDiluted