Name:	afl_CollateralRequirementsMinimumPercentageCollateralToFairValueOfSecuritiesLoanedUnderSecurityLendingTransactions
Namespace Prefix:	afl_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Commercial Mortgage Loan Commitments

No definition available.

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

Number of investments reclassified during the period from the held-to-maturity portfolio to the available-for-sale portfolio.

No definition available.

Name:	afl_HeldToMaturitySecuritiesTransferredToAvailableForSaleSecuritiesNumberOfInvestments
Namespace Prefix:	afl_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

Middle Market Loan Commitment

No definition available.

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

Middle Market Loan Program Unfunded Amount

No definition available.

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

Number of Issuers

No definition available.

Name:	afl_NumberOfIssuers
Namespace Prefix:	afl_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

Other investments held in unit trust, net of reserves, amortized cost

No definition available.

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

Other investments, net of reserves, amortized cost

No definition available.

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

Carrying amount of cash and investment securities on deposit with state regulatory authorities in connection with capital requirements.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 320
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=28366721&loc=d3e22002-158495

Name:	us-gaap_AssetsHeldByInsuranceRegulators
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

This item represents the cost of debt securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (aa)
-URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27161-111563

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.2)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Name:	us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

This item represents the cost of equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments for other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

No definition available.

Name:	us-gaap_AvailableForSaleEquitySecuritiesAmortizedCostBasis
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Amount of debt securities categorized neither as held-to-maturity nor trading.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 25
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=65884222&loc=d3e22054-111558

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=66010992&loc=d3e26610-111562

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (aa)
-URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27161-111563

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 320
-Section 50
-Paragraph 2
-Subparagraph (b)-(g)
-URI http://asc.fasb.org/extlink&oid=6957658&loc=d3e62557-112803

Name:	us-gaap_AvailableForSaleSecuritiesDebtSecurities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Amount of equity securities categorized neither as held-to-maturity nor as trading.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 25
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=65884222&loc=d3e22054-111558

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=66010992&loc=d3e26610-111562

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 320
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6957658&loc=d3e62557-112803

Name:	us-gaap_AvailableForSaleSecuritiesEquitySecurities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

For any transfer of securities categorized as held-to-maturity, this item represents the net carrying amount of the transferred security to another category of investments in debt and equity securities (trading or available-for-sale).

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 10
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27405-111563

Name:	us-gaap_HeldToMaturitySecuritiesTransferredSecurityAtCarryingValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

This item represents the unrealized gain (loss) recognized in other comprehensive income (a separate component of shareholders' equity) as a result of securities categorized as held-to-maturity being transferred to the available-for-sale securities category.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 10
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27405-111563

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

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.

No definition available.

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

Name:	us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis=us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis=us-gaap_VariableInterestEntityNotPrimaryBeneficiaryMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=afl_MiddlemarketloansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_BankLoanObligationsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=afl_CommercialmortgageloansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: