v2.4.1.9

Commitments and Contingencies - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 27, 2014	Dec. 28, 2013
Other Commitments [Line Items]
Amount for which the Company is contingently liable under repurchase agreements	5,970,000dvly_AmountForWhichCompanyIsContingentlyLiableUnderRepurchaseAgreements	$ 3,815,000dvly_AmountForWhichCompanyIsContingentlyLiableUnderRepurchaseAgreements
Accrued repurchase commitment	179,065dvly_AccruedRepurchaseCommitmentCurrent	$ 152,510dvly_AccruedRepurchaseCommitmentCurrent
Minimum [Member]
Other Commitments [Line Items]
Period in which DVH is obligated to pay	18 months
Maximum [Member]
Other Commitments [Line Items]
Period in which DVH is obligated to pay	24 months

X

- Definition

Accrued repurchase commitment, current.

+ References

No definition available.

+ Details

Name:	dvly_AccruedRepurchaseCommitmentCurrent
Namespace Prefix:	dvly_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

Amount for which company is contingently liable under repurchase agreements.

+ References

No definition available.

+ Details

Name:	dvly_AmountForWhichCompanyIsContingentlyLiableUnderRepurchaseAgreements
Namespace Prefix:	dvly_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

Repurchase agreements payment period.

+ References

No definition available.

+ Details

Name:	dvly_RepurchaseAgreementsPaymentPeriod
Namespace Prefix:	dvly_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	us-gaap_OtherCommitmentsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: