Vesting Time-Based Restricted Stock Units (Detail) - USD ($) $ in Thousands	9 Months Ended
Oct. 03, 2020	Oct. 05, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividends at Vesting	$ 109	$ 1,361
Time-Based Restricted Stock Units \| Fiscal Year Vested 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividends at Vesting	55
Income tax expense related to share-based payments	57
Fair Value at Vesting	$ 1,584

Amount of increase (decrease) in additional paid in capital (APIC) resulting from a tax benefit (deficiency) associated with an share-based compensation plan other than an employee stock ownership plan (ESOP).

No definition available.

+ Details

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

- Definition

Amount of paid and unpaid cash, stock, and paid-in-kind dividends declared for award under share-based payment arrangement.

+ References

No definition available.

+ Details

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

- Definition

Fair value of share-based awards for which the grantee gained the right by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash.

+ 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 (d)(2)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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_AwardTypeAxis=flo_TimeBasedRestrictedStockUnitsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VestingAxis=flo_ShareBasedCompensationAwardTrancheFourMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: