Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form 8-K
-Section 1.05
-Subsection a

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form 6-K
-Section General Instruction
-Subsection B

Name:	cyd_MaterialCybersecurityIncidentLineItems
Namespace Prefix:	cyd_
Data Type:	i:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Cybersecurity Incident, Expenses

+ References

No definition available.

+ Details

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

- Definition

Carrying value as of the balance sheet date of payments made in excess of existing cash balances, which will be honored by the bank but reflected as a loan to the entity. Overdrafts generally have a very short time frame for correction or repayment and are therefore more similar to short-term bank financing than trade financing.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(20))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section 45
-Paragraph 10
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481573/470-10-45-10

+ Details

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

- Definition

Amount by which inventory stated at last-in first-out (LIFO) is less than (in excess of) inventory stated at other inventory cost methods.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(6)(c))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

+ Details

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

- Definition

Amount of cash inflow for proceeds from settlement of insurance claim, classified as operating activities. Excludes insurance settlement classified as investing activities.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Name Accounting Standards Codification
-Section 45
-Paragraph 16
-Subparagraph (c)
-SubTopic 10
-Topic 230
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-16

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 21B
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-21B

+ Details

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

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeStatementLocationAxis=unfi_GrossProfitMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeStatementLocationAxis=us-gaap_OperatingExpenseMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

SIGNIFICANT ACCOUNTING POLICIES (Details) - USD ($) $ in Millions		3 Months Ended	6 Months Ended
	Feb. 26, 2026	Jan. 31, 2026	Jan. 31, 2026	Aug. 02, 2025
Material Cybersecurity Incident [Line Items]
Cybersecurity incident, expenses		$ 7	$ 21
Gain from cybersecurity insurance recoveries		10	20
Net book overdrafts		287	287	$ 267
LIFO reserve		359	359	$ 349
Subsequent event
Material Cybersecurity Incident [Line Items]
Gain from cybersecurity insurance recoveries	$ 10
Gross Profit
Material Cybersecurity Incident [Line Items]
Cybersecurity incident, expenses		6	19
Operating expenses
Material Cybersecurity Incident [Line Items]
Cybersecurity incident, expenses		$ 1	$ 2