The initial applicable margin percentage points added to the debt instrument.

No definition available.

Name:	unfi_DebtInstrumentInitialApplicableMargin
Namespace Prefix:	unfi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Real estate term backed loan

+ References

No definition available.

+ Details

Name:	unfi_Realestatetermbackedloan
Namespace Prefix:	unfi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Sum of the carrying values as of the balance sheet date of all debt, including all short-term borrowings, long-term debt, collateralized financings, and capital lease obligations.

+ References

No definition available.

+ Details

Name:	us-gaap_BorrowedFunds
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The reference rate for the variable rate of the debt instrument, such as LIBOR or the US Treasury rate and the maturity of the reference rate used, such as three months or six months LIBOR.

+ References

No definition available.

+ Details

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

- Definition

The cash inflow during the period from additional borrowings in aggregate debt. Includes proceeds from short-term and long-term debt.

+ References

No definition available.

+ Details

Name:	us-gaap_ProceedsFromIssuanceOfDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The cash outflow during the period from the repayment of aggregate short-term and long-term debt. Excludes payment of capital lease obligations.

+ References

No definition available.

+ Details

Name:	us-gaap_RepaymentsOfDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

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

SUBSEQUENT EVENTS (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		3 Months Ended					3 Months Ended	0 Months Ended
	Nov. 01, 2014 Term Loan	Aug. 14, 2014 Term Loan	Nov. 01, 2014 Minimum Term Loan	Nov. 01, 2014 Maximum Term Loan	Nov. 01, 2014 Federal funds effective rate Term Loan	Nov. 01, 2014 One-month LIBOR Term Loan	Aug. 14, 2014 Nine month LIBOR Term Loan	Nov. 01, 2014 LIBOR Term Loan	May 31, 2012 Term Loan
Subsequent Event [Line Items]
Initial borrowings under term loan agreement		$ 150.0
Repayments of Debt	2.5
Proceeds from Issuance of Debt			10.0	50.0
Reference rate					federal funds effective rate	one-month LIBOR		for one, two, three or six months or, if approved by all affected lenders, nine months
Spread on reference rate (as a percent)					0.50%	1.00%
Real estate term backed loan									$ 200.0
Initial applicable margin		2.50%					1.50%