Represents the minimum amount of awards to be deferred by participants during the year.

No definition available.

Name:	unfi_DefinedBenefitPlanAmountOfAwardsDeferredByParticipantsMinimum
Namespace Prefix:	unfi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The total amount of the benefits expected to be paid.

+ References

No definition available.

+ Details

Name:	unfi_DefinedBenefitPlanExpectedFutureBenefitPayments
Namespace Prefix:	unfi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Represents the percentage of awards to be deferred by participants during the year.

+ References

No definition available.

+ Details

Name:	unfi_DefinedBenefitPlanPercentageOfAwardsDeferredByParticipants
Namespace Prefix:	unfi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the maximum percentage of base salary to be deferred by participants during the year.

+ References

No definition available.

+ Details

Name:	unfi_DefinedBenefitPlanPercentageOfBaseSalaryDeferredByParticipantsMaximum
Namespace Prefix:	unfi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the maximum percentage of director fees, employee bonuses and commissions to be deferred by participants during the year.

+ References

No definition available.

+ Details

Name:	unfi_DefinedBenefitPlanPercentageOfDirectorFeesEmployeeBonusesAndCommissionsDeferredByParticipantsMaximum
Namespace Prefix:	unfi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The interest rate used to adjust for the time value of money for the plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (k)(1)

-URI http://asc.fasb.org/extlink&oid=28361610&loc=d3e1928-114920

+ Details

Name:	us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Details

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

- Definition

The amount of estimated future defined benefit annual plan participant benefits covered by insurance contracts issued by the employer or its related parties.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (n)

-URI http://asc.fasb.org/extlink&oid=28361610&loc=d3e1928-114920

+ Details

Name:	us-gaap_DefinedBenefitPlanEstimatedAmountOfPlanParticipantsFutureBenefitsCoveredByInsuranceContractsIssuedByEmployerOrRelatedParties
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

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

- Definition

Amount of benefits expected to be paid in the five fiscal years after the fifth fiscal year following the latest fiscal year from a defined benefit plan.

+ References