Basis of presentation.

No definition available.

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

Accordion feature amount for the credit facility

+ References

No definition available.

+ Details

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

- Definition

Reimbursement of previously incurred costs on inferior ingredients.

+ References

No definition available.

+ Details

Name:	flo_ReimbursementOfPreviouslyIncurredCostsOnInferiorIngredients
Namespace Prefix:	flo_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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

Amount of direct write-downs of accounts receivable charged against the allowance.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 13
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=121599337&loc=SL82919249-210447

+ Details

Name:	us-gaap_AllowanceForDoubtfulAccountsReceivableWriteOffs
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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

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

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3291-108585

+ Details

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

- Details

Name:	srt_ProductOrServiceAxis=flo_FoodServiceCustomersMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- 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:

Basis of Presentation - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended	4 Months Ended	9 Months Ended		12 Months Ended
	Jul. 11, 2020	Apr. 18, 2020	Oct. 03, 2020	Oct. 05, 2019	Dec. 28, 2019
Basis of Presentation [Line Items]
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.
Additional bad debt allowance			$ 6,627
Costs recognized on inferior ingredients				$ 1,400
Reimbursements of previously incurred inferior ingredients costs				$ 1,800
Food Service Customers
Basis of Presentation [Line Items]
Additional bad debt allowance		$ 2,700
Outstanding Trade Receivables \| Wal-Mart/Sam's Club \| Customer Concentration Risk
Basis of Presentation [Line Items]
Concentration risk percentage			19.10%		18.90%
Unsecured Credit Facility
Basis of Presentation [Line Items]
Line of credit facility, additional borrowing capacity		$ 200,000	$ 200,000
Repayments of debt	$ 61,300
Debt facility remaining borrowing capacity			$ 477,600