v2.4.1.9
Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)
12 Months Ended
Dec. 27, 2014
Dec. 28, 2013
Dec. 31, 2012
Schedule Of Significant Accounting Policies [Line Items]      
Allowance for doubtful accounts receivable $ 18,500us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent $ 15,000us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent  
Periodic installments of principal and interest 24 months    
Allowance for doubtful loans and leases receivable 91,640us-gaap_LoansAndLeasesReceivableAllowance 201,960us-gaap_LoansAndLeasesReceivableAllowance 329,500us-gaap_LoansAndLeasesReceivableAllowance
Definite-lived intangible assets 0us-gaap_FiniteLivedIntangibleAssetsNet 0us-gaap_FiniteLivedIntangibleAssetsNet  
Advertising costs 64,025us-gaap_AdvertisingExpense 43,446us-gaap_AdvertisingExpense  
Company dilutive common stock equivalent shares 0dvly_DilutiveCommonStockOutstanding 0dvly_DilutiveCommonStockOutstanding  
Sales Revenue, Net [Member] | Customer One [Member]      
Schedule Of Significant Accounting Policies [Line Items]      
Percentage of sales accounted to total revenue 10.00%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= us-gaap_SalesRevenueNetMember
/ us-gaap_MajorCustomersAxis
= dvly_CustomerOneMember
10.00%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= us-gaap_SalesRevenueNetMember
/ us-gaap_MajorCustomersAxis
= dvly_CustomerOneMember
 
Maximum [Member]      
Schedule Of Significant Accounting Policies [Line Items]      
Insured amount by the federal deposit insurance corporation $ 250,000us-gaap_CashFDICInsuredAmount
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
   
Estimated useful life of property, plant and equipment 40 years    
Minimum [Member]      
Schedule Of Significant Accounting Policies [Line Items]      
Estimated useful life of property, plant and equipment 5 years