Investments in Debt Securities, Perpetual Securities and Equity Securities (Parenthetical) (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2010
Schedule of Available-for-sale Securities [Line Items]
Other-than-temporary non-credit-related losses	$ (4)

Unrealized gains and losses, before tax, on securities for which an other-than-temporary impairment has been recognized in accumulated other comprehensive income for non-credit-related factors.

No definition available.

Name:	afl_AccumulatedOtherComprehensiveIncomeLossUnrealizedGainsAndLossesOnOtherThanTemporarilyImpairedSecuritiesBeforeTax
Namespace Prefix:	afl_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant