Weighted Average Assumptions Used for Pension Plans (Detail)	12 Months Ended
Jan. 02, 2016	Jan. 03, 2015	Dec. 28, 2013
Defined Benefit Plan Disclosure [Line Items]
Weighted average assumptions used to determine net periodic cost, Expected return on plan assets	8.00%
Pension plans
Defined Benefit Plan Disclosure [Line Items]
Weighted average assumptions used to determine benefit obligations, Discount rate	4.25%	4.00%	4.75%
Weighted average assumptions used to determine benefit obligations, Rate of compensation increase	3.00%	4.00%	4.00%
Weighted average assumptions used to determine net periodic cost, Discount rate	4.00%	4.75%	4.00%
Weighted average assumptions used to determine net periodic cost, Expected return on plan assets	8.00%	8.00%	8.00%
Weighted average assumptions used to determine net periodic cost, Rate of compensation increase	4.00%	4.00%	4.00%
Pension plans \| Benefit Obligations
Defined Benefit Plan Disclosure [Line Items]
Weighted average assumptions used to determine Measurement date	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Pension plans \| Net (Income) Cost
Defined Benefit Plan Disclosure [Line Items]
Weighted average assumptions used to determine Measurement date	Jan. 01, 2015	Jan. 01, 2014	Jan. 01, 2013
Postretirement Benefit Plans \| Benefit Obligations
Defined Benefit Plan Disclosure [Line Items]
Weighted average assumptions used to determine benefit obligations, Discount rate	3.83%	3.50%	4.31%
Weighted average assumptions used to determine benefit obligations, Measurement date	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Health care cost trend rate, Initial rate	8.00%	8.00%	8.50%
Health care cost trend rate, Ultimate rate	5.00%	5.00%	5.00%
Health care cost trend rate, Year trend reaches the ultimate rate	2022	2021	2021
Postretirement Benefit Plans \| Net Periodic Benefit Cost
Defined Benefit Plan Disclosure [Line Items]
Weighted average assumptions used to determine net periodic cost, Discount rate	3.50%	4.31%	3.34%
Health care cost trend rate, Initial rate	8.00%	8.50%	8.00%
Health care cost trend rate, Ultimate rate	5.00%	5.00%	5.00%
Health care cost trend rate, Year trend reaches the ultimate rate	2021	2021	2019
Weighted average assumptions used to determine net periodic cost, Measurement date	Jan. 01, 2015	Jan. 01, 2014	Jan. 01, 2013

Defined benefit plan assumptions used calculating benefit obligation measurement date.

No definition available.

Name:	flo_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationMeasurementDate
Namespace Prefix:	flo_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Defined Benefit Plan Assumptions Used Calculating Net Periodic Benefit Cost Measurement Date

+ References

No definition available.

+ Details

Name:	flo_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostMeasurementDate
Namespace Prefix:	flo_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Defined benefit plans measurement date.

+ References

No definition available.

+ Details

Name:	flo_DefinedBenefitPlansMeasurementDate
Namespace Prefix:	flo_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

The interest rate used to adjust for the time value of money for the plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (k)(1)
-URI http://asc.fasb.org/extlink&oid=58740216&loc=d3e1928-114920

+ Details

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

- Definition

Expected rate of compensation increases (for pay-related plans).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (k)(2)
-URI http://asc.fasb.org/extlink&oid=58740216&loc=d3e1928-114920

+ Details

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

- Definition

The interest rate used to adjust for the time value of money.

+ References

+ Details

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

- Definition

An assumption as to the rate of return on plan assets reflecting the average rate of earnings expected on the funds invested or to be invested to provide for the benefits included in the benefit obligation.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Expected Long-Term Rate of Return on Plan Assets
-URI http://asc.fasb.org/extlink&oid=6512046

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (k)(3)
-URI http://asc.fasb.org/extlink&oid=58740216&loc=d3e1928-114920

+ Details

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

- Definition

Expected rate of compensation increases (for pay-related plans).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (k)(2)
-URI http://asc.fasb.org/extlink&oid=58740216&loc=d3e1928-114920

+ Details

Name:	us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostRateOfCompensationIncrease
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
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_DefinedBenefitPlanDisclosureLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The assumed health care cost trend rate for the next year used to measure the expected cost of benefits covered by the plan (gross eligible charges). This is based upon the annual rate of change in the cost of health care benefits currently provided by the postretirement benefit plan, due to factors other than changes in the composition of the plan population by age and dependency status.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Health Care Cost Trend Rate
-URI http://asc.fasb.org/extlink&oid=6514820

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (l)
-URI http://asc.fasb.org/extlink&oid=58740216&loc=d3e1928-114920

+ Details

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

- Definition

The ultimate trend rate for health care costs.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (l)
-URI http://asc.fasb.org/extlink&oid=58740216&loc=d3e1928-114920

+ Details

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

- Definition

Year the ultimate health care cost trend rate is expected to be reached, in CCYY format.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (l)
-URI http://asc.fasb.org/extlink&oid=58740216&loc=d3e1928-114920

+ Details

Name:	us-gaap_DefinedBenefitPlanYearThatRateReachesUltimateTrendRate
Namespace Prefix:	us-gaap_
Data Type:	xbrli:gYearItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis=us-gaap_PensionPlansDefinedBenefitMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=flo_BenefitObligationsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementEquityComponentsAxis=flo_NetIncomeCostMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis=us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=flo_NetPeriodicBenefitCostMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: