Stock-Based Compensation (Performance-Contingent Total Shareholder Return Shares) - Additional Information (Detail) - shares	4 Months Ended
Apr. 24, 2021	Apr. 18, 2020
Performance Contingent Total Shareholders Return Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
Total Shareholders Return
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based payment award, fair value assumptions, method used	Inputs into the model included the following for the company and comparator companies: (i) TSR from the beginning of the performance cycle through the measurement date; (ii) volatility; (iii) risk-free interest rates; and (iv) the correlation of the comparator companies’ TSR. The inputs are based on historical capital market data.
Total Shareholders Return \| Omnibus Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards vested during period	0	0

Vesting period for return on invested capital awards issued after 2012.

No definition available.

Name:	flo_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestingPeriodOne
Namespace Prefix:	flo_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(2)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Description of method used to estimate fair value of award under share-based payment arrangement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (f)(1)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

+ Details

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

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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

- Details

Name:	us-gaap_DeferredCompensationArrangementWithIndividualShareBasedPaymentsByTypeOfDeferredCompensationAxis=flo_ShareholdersReturnSharesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DeferredCompensationArrangementWithIndividualShareBasedPaymentsByTypeOfDeferredCompensationAxis=flo_ShareholdersReturnMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PlanNameAxis=flo_OmnibusPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: