COMMITMENTS AND CONTINGENT LIABILITIES - Additional Information (Details) $ in Millions, ¥ in Billions	3 Months Ended
Mar. 31, 2022 JPY (¥)	Mar. 31, 2022 USD ($)	Mar. 31, 2017 USD ($)
Commitments and Contingencies Disclosure [Line Items]
Loss contingency accrual, insurance-related assessment, discount rate			4.25%
Loss contingency, discounted amount of insurance-related assessment liability			$ 62
Loss contingency, undiscounted amount of insurance-related assessment liability			94
Loss contingency, insurance-related assessment, discounted amount of premium tax offset			48
Loss contingency, insurance-related assessment, undiscounted amount of premium tax offset			74
Loss contingency, loss in period			$ 14
Information Technology and Data Services Company Application Maintenance and Development Services
Commitments and Contingencies Disclosure [Line Items]
Outsourcing agreement, remaining term	4 years	4 years
Outsourcing agreement, aggregate remaining cost	¥ 8.0	$ 65

Commitments and Contingencies Disclosure [Line Items]

No definition available.

Name:	afl_CommitmentsAndContingenciesDisclosureLineItems
Namespace Prefix:	afl_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of insurance-related assessment liability that is expected to be recovered through premium tax offset (discounted) based on current laws applied to in-force policies.

+ References

No definition available.

+ Details

Name:	afl_Losscontingencyinsurancerelatedassessmentdiscountedamountofpremiumtaxoffset
Namespace Prefix:	afl_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The amount of insurance-related assessment liability that is expected to be recovered through premium tax offset (undiscounted) based on current laws applied to in-force policies.

+ References

No definition available.

+ Details

Name:	afl_Losscontingencyinsurancerelatedassessmentundiscountedamountofpremiumtaxoffset
Namespace Prefix:	afl_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The minimum amount the entity agreed to spend under the long-term purchase commitment.

+ References

No definition available.

+ Details

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

- Definition

Period covered by the long-term purchase commitment, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_LongtermPurchaseCommitmentPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The rate applied as of the balance sheet date to reduce the undiscounted amount of a guarantee fund and other insurance-related assessments to present value.

+ References

+ Details

Name:	us-gaap_LossContingencyAccrualInsuranceRelatedAssessmentDiscountRate
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The present value of the liability as of the balance sheet date representing required funding mandated by statute or regulatory authority that is related directly or indirectly to underwriting activities, including pools for self-insurance and excluding premium taxes and income taxes. The funds derived from the assessments generally enable a government guarantor to pay insurance claims in the event that the underwriting insurer is insolvent or otherwise unable to meet its payment obligations.

+ References

+ Details

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

- Definition

The amount of loss pertaining to the specified contingency that was charged against earnings in the period, including the effects of revisions in previously reported estimates.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=121557415&loc=d3e14326-108349

+ Details

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

- Definition

The liability as of the balance sheet date representing required funding mandated by statute or regulatory authority that is related directly or indirectly to underwriting activities, including pools for self-insurance and excluding premium taxes and income taxes. The funds derived from the assessments generally enable a government guarantor to pay insurance claims in the event that the underwriting insurer is insolvent or otherwise unable to meet its payment obligations.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 405
-SubTopic 30
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6392405&loc=d3e24119-109301

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 405
-SubTopic 30
-Section 15
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=99384745&loc=d3e23169-109297

+ Details

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

- Details

Name:	us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=afl_InformationTechnologyandDataServicesCompanyApplicationMaintenanceandDevelopmentServicesFirstAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: