Basis of presentation.

No definition available.

Name:	flo_BasisOfPresentationLineItems
Namespace Prefix:	flo_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Business consulting cost.

+ References

No definition available.

+ Details

Name:	flo_BusinessConsultingCost
Namespace Prefix:	flo_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Costs recognized on inferior ingredients.

+ References

No definition available.

+ Details

Name:	flo_CostsRecognizedOnInferiorIngredients
Namespace Prefix:	flo_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Debt facility remaining borrowing capacity.

+ References

No definition available.

+ Details

Name:	flo_DebtFacilityRemainingBorrowingCapacity
Namespace Prefix:	flo_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Debt Instrument Maturity Year

+ References

No definition available.

+ Details

Name:	flo_DebtInstrumentMaturityYear
Namespace Prefix:	flo_
Data Type:	xbrli:gYearItemType
Balance Type:	na
Period Type:	duration

- Definition

Project cost.

+ References

No definition available.

+ Details

Name:	flo_ProjectCost
Namespace Prefix:	flo_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Additional information about the entity or its reportable segments that may contribute to an understanding of the enterprise.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6374474&loc=d3e8352-108598

+ Details

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

- Definition

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 42
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e9054-108599

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 18
-URI http://asc.fasb.org/extlink&oid=99393423&loc=d3e6351-108592

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=121572278&loc=d3e13531-108611

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 21
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121572278&loc=d3e13537-108611

Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=99393423&loc=d3e6404-108592

+ Details

Name:	us-gaap_ConcentrationRiskPercentage1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=119993939&loc=d3e28551-108399

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

+ Details

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

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

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

- Details

Name:	us-gaap_ConcentrationRiskByBenchmarkAxis=us-gaap_AccountsReceivableMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_MajorCustomersAxis=flo_WalmartSamsClubMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ConcentrationRiskByTypeAxis=us-gaap_CustomerConcentrationRiskMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=flo_UnsecuredCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=flo_TwoPointFourPercentSeniorNotesDueTwoThousandThirtyOneMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=flo_FourPointThreeSevenFivePercentSeniorNotesDueTwoThousandTwentyTwoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Basis of Presentation - Additional Information (Detail) - USD ($)	4 Months Ended		12 Months Ended
	Apr. 24, 2021	Apr. 18, 2020	Jan. 02, 2021	Mar. 09, 2021	Oct. 03, 2020	Apr. 03, 2012
Basis of Presentation [Line Items]
Debt instrument face amount	$ 900,000,000		$ 800,000,000
Segment reporting, description	The company has one operating segment based on the nature of products the company sells, intertwined production and distribution model, the internal management structure and information that is regularly reviewed by the chief executive officer (“CEO”), who is the chief operating decision maker, for the purpose of assessing performance and allocating resources.
Business consulting cost	$ 5,000,000.0
Project cost		$ 0
Additional costs associated with receiving inferior ingredients	$ 100,000
Outstanding Trade Receivables \| Wal-Mart/Sam's Club \| Customer Concentration Risk
Basis of Presentation [Line Items]
Concentration risk percentage	21.30%		18.80%
Unsecured Credit Facility
Basis of Presentation [Line Items]
Debt facility remaining borrowing capacity					$ 670,700,000
2031 Notes
Basis of Presentation [Line Items]
Debt instrument face amount	$ 500,000,000			$ 500,000,000.0
Debt instrument interest rate	2.40%			2.40%
Final Maturity	2031
2022 Notes
Basis of Presentation [Line Items]
Debt instrument face amount	$ 400,000,000.0		$ 400,000,000			$ 400,000,000.0
Debt instrument interest rate	4.375%					4.375%
Final Maturity	2022