Summary of Credit-Related Impairment Losses on Other-Than-Temporarily-Impaired Securities With Bifurcated Losses (Detail) (USD $) In Millions	3 Months Ended	6 Months Ended
Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Schedule of Investments [Line Items]
Cumulative credit loss impairments, beginning of period	$ 4	$ 23	$ 13	$ 24
Securities sold during period	0	(10)	(9)	(11)
Cumulative credit loss impairments, end of period	$ 4	$ 13	$ 4	$ 13

Name:

afl_ReductionsInCreditLossImpairmentsRealizedForSecuritiesWithBifurcatedLossesSecuritiesSoldDuringPeriod

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afl

Data Type:

xbrli:monetaryItemType

Balance Type:

debit

Period Type:

duration